Vibration dampening material and method of making same
The material minimizes vibration transmitted through the material that includes shear thickening fluids and magnetorheological fluids, which are generally referred to as “resistive fluids.”
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The field of the invention is a vibration-reducing material that uses shear thickening fluid.
BACKGROUNDShear thickening fluids (STFs), or dilatants, is the general name for fluids that exhibit a non-Newtonian flow and in particular, exhibit large increases in viscosity with increasing shear stress. Stated more simply, a shear thickening fluid is flowable and flexible during normal handling. During impact or puncture, i.e. shear, the fluid becomes nearly instantaneously rigid.
A common example of a shear thickening fluid can be made from a mix or corn starch and water. When the mixture nears the critical concentration—with a creamy consistency—the mixture will exhibit its shear thickening fluid. Once in this state, the application of a sharp force by stabbing or impact results in the fluid behaving like a solid. A slow application of force, however, results in the fluid acting like a liquid.
The use of shear thickening fluids have gained increased attention for use in body armor, such as that disclosed in US Publication 2005/0266748 to Wagner, herein incorporated by reference. Wagner focuses on impregnating fibers and yarns with STFs.
Another type of fluid that can both flow and become rigid is a magnetorheological fluid (MRF). It is a suspension of microsized magnetic particles in a carrier fluid, usually a type of oil. When subjected to a magnetic field, the fluid's flow increases, turning it into a viscoelastic solid. The difference between MRFs and STFs is that MRFs are rigid upon activation—but not necessarily impact.
The problem with both STFs and MRFs is that their rigidity transmits vibration over a greater area than the impact, but almost directly through the material.
SUMMARYThe inventive material described herein minimizes vibration transmitted through the material that includes STFs and MRFs, which shall generally be referred to herein as “resistive fluids.” Each of the materials, and then their uses on certain items will be described first in summary, and then in detail.
The first material comprises first and second elastomer layers; and a reinforcement layer comprising resistive fluids disposed between and generally separating the first and second elastomer layers. The reinforcement layer comprising a layer of high tensile strength fibrous material, typically with a Young's Modulus between 0.01 and 5 (GPa).
The second material comprises first and second elastomer layers and a reinforcement layer comprising resistive fluids disposed between and generally separating the first and second elastomer layers. The reinforcement layer has a plurality of high tensile strength fibrous material connected to the first and second elastomer layers and located between the first and second elastomer layers. The high tensile strength fibrous material is generally compliant only in a direction generally perpendicular to the major material surface so as to be generally non energy storing in the direction. The high tensile strength fibrous material is also generally interlocked in and generally held in position by the first and second elastomer layers. Finally, the high tensile strength fibrous material generally distributes impact energy parallel to the major material surface and into the first and second elastomer layers.
The third material comprises a first elastomeric layer of vibration absorbing material which is substantially free of voids therein; a second elastomeric layer which includes an aramid material comprising resistive fluids therein and that is disposed on the first elastomeric layer, wherein the aramid material distributes vibration to facilitate vibration dampening; and a third elastomeric layer disposed on the second elastomeric layer and adapted for gripping.
The fourth material comprises a first elastomeric layer adapted to absorb vibration, the first elastomeric layer being substantially free of voids therein;
a second elastomeric layer which includes an aramid material comprising resistive fluids therein and that is disposed on the first elastomeric layer, the aramid material comprising a plurality of individual strips of aramid of different sizes, wherein the aramid material distributes vibration to facilitate vibration dampening, the second elastomeric layer being substantially free of voids therein; and
a third elastomeric layer that is disposed on the second elastomeric layer, the third elastomeric layer being substantially free of voids.
The fifth material comprises: a first elastomeric layer of vibration absorbing material which is substantially free of voids therein; a second elastomeric layer that includes an aramid material comprising resistive fluids therein and that is disposed on the first elastomeric layer, wherein the aramid material distributes vibration to facilitate vibration dampening; and a third elastomeric layer disposed on the second elastomeric layer.
The sixth material comprises: a first elastomeric layer adapted to absorb vibration, the first elastomeric layer being substantially free of voids therein;
a second elastomeric layer which includes an aramid material comprising resistive fluids therein and that is disposed on the first elastomeric layer, the aramid material comprising a plurality of individual strips of aramid of different sizes, wherein the aramid material distributes vibration to facilitate vibration dampening, the second elastomeric layer being substantially free of voids therein; and
a third elastomeric layer that is disposed on the second elastomeric layer, the third elastomeric layer being substantially free of voids.
The seventh material comprises: a first layer adapted to absorb vibration and being formed by an elastomer that is substantially free of voids therein;
a second layer which includes an aramid material comprising resistive fluids therein and that is disposed on the first layer, the aramid material comprising a plurality of individual strips of aramid of generally equal sizes, wherein the aramid material distributes vibration to facilitate vibration dampening, the second layer being substantially free of voids therein, the plurality of individual aramid strips being generally parallel to each other; and
a third layer formed by an elastomer that is substantially free of voids.
The eighth material comprises: a first elastomeric layer of vibration absorbing material which is substantially free of voids therein;
a second layer including fiberglass material comprising resistive fluids and that is disposed on the first elastomeric layer, wherein the fiberglass material distributes vibration to facilitate vibration dampening, wherein the fiberglass material forms a substantially imperforate sheet; and
a third elastomeric layer disposed on the second elastomeric layer.
The ninth material comprises: a first elastomeric layer of vibration absorbing material which is substantially non-porous;
a second layer including a fiberglass material comprising resistive fluids and that is disposed on the first elastomeric layer, wherein the fiberglass material distributes vibration to facilitate vibration dampening, wherein the fiberglass material forms a plurality of individual strips that are generally co-aligned within a common plane that extends generally throughout the second layer; and
a third elastomeric layer disposed on the second elastomeric layer.
The tenth material comprises: a first elastomeric layer of vibration absorbing material which is substantially free of voids therein;
a second layer including high tensile strength fibrous material comprising resistive fluids and that is disposed on the first elastomeric layer, wherein the high tensile strength fibrous material distributes vibration to facilitate vibration dampening, wherein the high tensile strength fibrous material forms a substantially imperforate sheet; and
a third elastomeric layer disposed on the second elastomeric layer.
The eleventh material comprises: first and second elastomer layers; and
a reinforcement layer disposed comprising resistive fluids between and generally separating the first and second elastomer layers, the reinforcement layer comprising a cloth layer formed of a plurality of woven high tensile fibrous material, the plurality of woven high tensile fibrous material being connected to the first and second elastomer layers generally uniformly throughout to provide substantially complete coverage between the first and second elastomer layers, the cloth layer being generally compliant only in a direction generally perpendicular to the first major surface so as to be generally non energy storing in the direction, wherein the high tensile fibrous material generally distributes impact energy parallel to the first major surface and into the first and second elastomer layers.
The twelfth material comprises: first and second elastomer layers; and
a reinforcement layer comprising resistive fluids disposed between and generally separating the first and second elastomer layers, the reinforcement layer comprising a cloth layer formed of fiberglass, the fiberglass being connected to the first and second elastomer layers generally uniformly throughout to provide substantially complete coverage between the first and second elastomer layers, the cloth layer being generally compliant only in a direction generally perpendicular to the first major surface so as to be generally non energy storing in the direction, wherein the fiberglass generally distributes impact energy parallel to the first major surface and into the first and second elastomer layers.
The thirteenth material comprises: first and second elastomer layers; and
a reinforcement layer comprising resistive fluids disposed between and generally separating the first and second elastomer layers, the reinforcement layer comprising a cloth layer formed of a plurality of woven high tensile fibrous material, the plurality of woven high tensile fibrous material being connected to the first and second elastomer layers generally uniformly throughout to provide substantially complete coverage between the first and second elastomer layers, the cloth layer being generally compliant only in a direction generally perpendicular to the first major surface so as to be generally non energy storing in the direction, the cloth layer is generally interlocked in and generally held in position by the first and second elastomer layers, wherein the high tensile fibrous material generally distributes impact energy parallel to the first major surface and into the first and second elastomer layers.
The fourteenth material comprises: first and second elastomer layers; and
a reinforcement layer comprising resistive fluids disposed between and generally separating the first and second elastomer layers, the reinforcement layer comprising a cloth layer formed of a plurality of woven high tensile fibrous material, the plurality of woven high tensile fibrous material being connected to the first and second elastomer layers generally uniformly throughout to provide substantially complete coverage between the first and second elastomer layers, the cloth layer being generally compliant only in a second direction so as to be generally non energy storing in the second direction, wherein the high tensile fibrous material generally distributes impact energy parallel to the first direction and into the first and second elastomer layers.
The fifteenth material comprises: an elastomer layer having a first plurality of fibers therein; and
a support structure comprising resistive fluids penetrated by and embedded on and/or within the elastomer layer, the support structure being semi-rigid and supporting the elastomer layer.
The sixteenth material comprises: an elastomer layer; and
a support structure comprising resistive fluids penetrated by and embedded on and/or within the elastomer layer, the support structure being formed of a second elastomer having a higher durometer than the elastomer layer such that the support structure is semi-rigid and supporting the elastomer layer.
The seventeenth material comprises: a first elastomer layer; and
a support structure comprising resistive fluids penetrated by and embedded on and/or within the elastomer layer, the support structure being semi-rigid or rigid and supporting the elastomer layer, the support structure having a first plurality of particles therein.
The eighteenth material comprises: a first elastomer layer; and
a support structure comprising resistive fluids formed by a second elastomer layer, the support structure being located and configured to support the first elastomer layer.
The nineteenth material comprises: a first elastomer layer; and
a support structure comprising resistive fluids located and configured to support the elastomer layer, the support structure having a first plurality of gel particles therein.
The twentieth material comprises: a tape body being stretchable along the longitudinal axis from a first position to a second position, in which the tape body is elongated by a predetermined amount relative to the first position, the tape body comprising:
a first elastomer layer defining a tape length, as measured along the longitudinal axis, of the tape body;
a support structure comprising resistive fluids disposed within the elastomer layer generally along the longitudinal axis in an at least partially non linear fashion while the tape body is in the first position so that a length of the support structure, as measured along a surface thereof, is greater than the tape length of the first elastomer layer; and
wherein when the tape body is stretched into the second position, the support structure is at least partially straightened so that the support structure is more linear, relative to when the tape body is in the first position, the straightening of the support structure causing energy to be dissipated and generally preventing further elongation of the elastomer layer along the longitudinal axis past the second position, the support structure comprising a plurality of fibers.
The twenty-first material comprises: a tape body being stretchable along the longitudinal axis from a first position to a second position, in which the tape body is elongated by a predetermined amount relative to the first position, the tape body comprising:
a first elastomer layer defining a tape length, as measured along the longitudinal axis, of the tape body;
a support structure comprising resistive fluids disposed at least partially within the elastomer layer generally along the longitudinal axis in an at least partially non linear fashion while the tape body is in the first position so that a length of the support structure, as measured along a surface thereof, is greater than the tape length of the first elastomer layer; and
wherein when the tape body is stretched into the second position, the support structure is at least partially straightened so that the support structure is more linear, relative to when the tape body is in the first position, the straightening of the support structure causing energy to be dissipated and generally preventing further elongation of the elastomer layer along the longitudinal axis past the second position.
Each of these materials could be used alone of in various combinations to reduce vibrations in the goods described herein.
BRIEF DESCRIPTION OF THE DRAWING(S)The foregoing summary, as well as the following detailed description of the preferred embodiments of the present invention will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments which are presently preferred. It is understood, however, that the invention is not limited to the precise arrangements and instrumentality shown. In the drawings:
Certain terminology is used in the following description for convenience only and is not limiting. The term “implement,” as used in the specification and in the claims, means “any one of a baseball bat, racket, hockey stick, softball bat, sporting equipment, firearm, or the like.” The above terminology includes the words above specifically mentioned, derivatives thereof, and words of similar import. Additionally, the words “a” and “one” are defined as including one or more of the referenced item unless specifically stated otherwise.
Referring to
The material 10 is preferably generally non elastic in a direction generally perpendicular “X” to a major material surface 316A (shown in
The first elastomer layer 12A acts a shock absorber by converting mechanical vibrational energy into heat energy. The high tensile strength fibrous material layer 14 redirects vibrational energy and provides increased stiffness to the material 10 to facilitate a user's ability to control an implement 20 encased, or partially encased, by the material 10. It is preferred, but not necessary, that the high tensile strength fibrous material layer 14 be formed of aramid material.
In one embodiment, the composite material 10 may have three generally independent and separate layers including the first elastomer layer 12A and a second elastomer layer 12B. Elastomer material provides vibration damping by dissipating vibrational energy. Suitable elastomer materials include, but are not limited urethane rubbers, silicone rubbers, nitrile rubbers, butyl rubbers, acrylic rubbers, natural rubbers, styrene-butadiene rubbers, and the like. In general, any suitable elastomer material can be used to form the first and second elastomer layers without departing from the scope of the present invention. For example the elastomer layers may be thermoset elastomer layers. Alternatively, the elastomer layers 12A, 12B can be thermoplastic or any material suitable for thermoforming. For example, when manufacturing some shaped articles, such as a golf club grip, it may be more efficient to first form the material 10 as a generally flat piece or sheet of material 10 which could then be reformed or thermoformed into the desired shaped article. Additionally, the material 10 may include a shrink wrap or shrinkable layer therein and/or thereon. The shrinkable layer can be heat and/or water activated.
The material 10 can include additional layers thereover, such as a generally rigid material or the like. For example, one or more generally rigid plates of rigid material can be positioned over the material 10 to distribute impact force over an increased amount of the material. This can be useful when using the material in umpire vests, bulletproof vests, shoulder pads, shoes, or in any other application where a generally rigid outer layer is desired.
The softness of elastomer materials can be quantified using Shore A durometer ratings. Generally speaking, the lower the durometer rating, the softer the material and the more effective an elastomer layer is at absorbing and dissipating vibration because less force is channeled through the elastomer. When a soft elastomer material is squeezed, an individual's fingers are imbedded in the elastomer which increases the surface area of contact between the user's hand and creates irregularities in the outer material surface to allow a user to firmly grasp any implement 20 covered, or partially covered, by the material. However, the softer the elastomer layers 12A, 12B, the less control a user has when manipulating an implement 20 covered by the elastomer. If the elastomer layer is too soft (i.e., if the elastomer layer has too low of a Shore A durometer rating), then the implement 20 may rotate unintentionally relative to a user's hand or foot. The material 10 of the present invention is preferably designed to use first and second elastomer layers 12A, 12B having Shore A durometer ratings that provide an optimum balance between allowing a user to precisely manipulate and control the implement 20 and effectively damping vibration during use of the implement 20.
It is preferable, but not necessary, that the elastomer used with the material 10 have a Shore A durometer of between approximately ten (10) and approximately eighty (80). It is preferred that the first elastomer layer have a Shore A durometer of between approximately ten (10) and approximately twenty-five (25) and that the second elastomer layer has a Shore A durometer of between approximately twenty-five (25) and approximately forty-five (45).
The first elastomer layer 12A is preferably used to slow down impact energy and to absorb vibrational energy and to convert vibrational energy into heat energy. This preferably, but not necessarily, allows the first elastomer layer to act as a pad as well as dissipate vibration. The second elastomer layer 12B is also used to absorb vibrational energy, but also provides a compliant and comfortable grip for a user to grasp (or provides a surface for a portion of a user's body, such as the under sole of a user's foot when the material 10 is formed as a shoe insert).
In one embodiment, the first elastomer layer 12A preferably has Shore A durometer of approximately fifteen (15) and the second elastomer layer has a Shore A durometer of approximately forty-two (42). If the first and second elastomer has generally the same Shore A durometer ratings, then it is preferable, but not necessary, that the first and second elastomer layers 12A, 12B have a Shore A durometer of fifteen (15), thirty-two (32), or forty-two (42).
The high tensile strength fibrous material layer 14 is preferably, but not necessarily, formed of aramid fibers. The fibers can be woven to form a cloth layer 16 that is disposed between and generally separates the first and second elastomer layers 12A, 12B. The cloth layer 16 can be formed of aramid fibers, high tensile strength fibers, fiberglass, or other types of fiber. It is preferred that the cloth layer 16 does not have suitable rigidity for use as an open gridwork having any significant energy storage capability. It is preferred that the material which forms the reinfocement layer 14 is generally bonded to the elastomer layers 12A, 12B. The cloth layer 16 preferably generally separates the first and second elastomer layers 12A, 12B causing the material 10 to have three generally distinct and separate layers 12A, 12B, 14. The high tensile strength fibrous material layer 14 blocks and redirects vibrational energy that passes through one of the elastomer layers 12A or 12B to facilitate the dissipation of vibrations. The high tensile strength fibers 18 redirect vibrational energy along the length of the fibers 18. Thus, when the plurality of high tensile strength fibers 18 are woven to form the cloth layer 16, vibrational energy emanating from the implement 20 that is not absorbed or dissipated by the first elastomer layer 12A is redistributed evenly along the material 10 by the cloth layer 16 and then further dissipated by the second elastomer layer 12B.
The cloth layer 16 is preferably generally interlocked in, generally affixed to, or generally fixed in position by the elastomer layers 12A, 12B in order for the cloth layer 16 to block and redirect vibrational energy to facilitate dissipation of vibrations.
It is preferable that the high tensile strength fibers 18 be formed of a suitable polyamide fiber of high tensile strength with a high resistance to elongation. However, those of ordinary skill in the art will appreciate from this disclosure that any aramid fiber suitable to channel vibration can be used to form the high tensile strength fibrous material layer 14 without departing from scope of the present invention. Additionally, those of ordinary skill in the art will appreciate from this disclosure that loose fibers or chopped fibers can be used to form the high tensile strength fibrous material layer 14 without departing from the scope of the present invention. The high tensile strength fibrous material may also be formed of fiberglass. The high tensile strength fibrous material preferably prevents the material 10 from substantially elongating in a direction parallel to the major material surfaces 316A, 316B during use. It is preferred that the amount of elongation is less than ten (10%) percent. It is more preferred that the amount of elongation is less than four (4%) percent. It is most preferred that the amount of elongation is less than one (1%) percent.
Those of ordinary skill in the art will appreciate from this disclosure that the material 10 can be formed of two independent layers without departing from the scope of the present invention. Accordingly, the material 10 can be formed of a first elastomer layer 12A and a high tensile strength fibrous material layer 14 (which may be woven into a cloth layer 16) that is disposed on the first elastomer 12A.
Referring to
When the material of the present invention forms an insert 310 for a shoe, the insert 310 includes a shoe insert body 312 having a generally elongated shape with an outer perimeter 314 configured to substantially conform to a sole of the shoe so that the shoe insert body 312 extends along an inner surface of the shoe from a location proximate to a heel of the shoe to a toe of the shoe. The shoe insert body 312 is preferably generally planar and formed by a reinforced elastomer material 10 that regulates and dissipates vibration. The shoe insert body 312 has first and second major surfaces 316A, 316B. The reinforced elastomer material 10 preferably includes first and second elastomer layers 12A, 12B. In one embodiment it is preferred that the first and second elastomer layers are generally free of voids therein and/or that the elastomer layers are formed by thermoset elastomer.
A reinforcement layer 14 is disposed between and generally separates the first and second elastomer layers 12A, 12B. The reinforcement layer 14 may include a layer formed of a plurality of high tensile strength fibrous material. Alternatively, the reinforcement layer may be formed of aramid, fiberglass, regular cloth, or the like. The reinforcement layer may be formed by woven fibers. In one embodiment, it is preferred that the reinforcement layer consist of only a single cloth layer of material.
The woven high tensile strength fibrous material is preferably connected to the first and second elastomer layers 12A, 12B generally uniformly throughout to provide substantially complete coverage between the first and second elastomer layers 12A, 12B. The cloth layer is generally compliant only in a direction “X” generally perpendicular to the first major surface 316A so as to be generally non energy storing in the direction “X”. Wherein the high tensile strength fibrous material 14 generally distributes impact energy parallel to the first major surface 316A and into the first and second elastomer layers 12A, 12B. The reinforcement layer 14 preferably prevents the shoe insert 310 from substantially elongating during use. The reinforced elastomer 10 can also be used as a sole for footwear or as part of a sole or insole for footwear. The reinforced elastomer can also be used to provide padding within or along a side or upper portion of a shoe or boot.
Referring to
Referring to
The reinforced elastomer material 10 includes first and second elastomer layers 12A, 12B. A reinforcement layer 14 is disposed between and generally separates the first and second elastomer layers 12A, 12B. In some embodiments, the elastomer layer is generally free of voids and/or is a thermoset elastomer. The reinforcement layer 14 preferably includes a layer of high tensile strength fibrous material. The high tensile strength fibrous material can be woven into a cloth, chopped, or otherwise distributed. Instead of the reinforcement layer 14 being formed by high tensile strength fibrous material, the reinforcement layer 14 can be formed by a layer of fiberglass, aramid, or any other suitable material.
The high tensile strength fibrous material layer 14 is connected to the first and second elastomer layers 12A, 12B generally uniformly throughout to provide substantially complete coverage between the first and second elastomer layers. This preferably prevents sliding movement between the reinforcement layer 14 and the elastomer layers 12A, 12B. The cloth layer is preferably generally compliant only in the second direction “Z” so as to be generally non energy storing in the second direction “Z”. The high tensile fibrous material generally distributes impact energy parallel to the first direction “Y” and into the first and second elastomer layers. This causes vibrational energy to be reduced and dampened rather than bounced back against the hand grasping the grip.
While the grip 22 will be described below in connection with a baseball or softball bat, those of ordinary skill in the art will appreciate that the grip 22 can be used with any of the equipment, tools, or devices mentioned above without departing from the scope of the present invention.
When the grip 22 is used with a baseball or softball bat, the grip 22 preferably covers approximately seventeen (17) inches of the handle of the bat as well as covers the knob (i.e., the proximal end 26 of the implement 20) of the bat. The configuration of the grip 22 to extend over a significant portion of the bat length contributes to increase vibrational damping. It is preferred, but not necessary, that the grip 22 be formed as a single, contiguous, one-piece member.
The baseball bat (or implement 20) has a handle 24 including a handle body 28 having a longitudinal portion 30 and a proximal end 26. The material 10 preferably encases at least some of the longitudinal portion 30 and the proximal end 26 of the handle 24. The material 10 can be produced as a composite having two generally separate and distinct layers including a first elastomer layer 12A and a high tensile strength fibrous material layer 14 (which may be a woven cloth layer 16) disposed on the elastomer layer 12A. The high tensile strength fibrous material layer 14 is preferably formed of woven fibers 18. The second elastomer layer 12B may be disposed on a major surface of the high tensile strength fibrous material layer 14 opposite from the first elastomer layer 12A.
As best shown in
Referring to
The panel body 324 is formed by a reinforced elastomer material that regulates and dissipates vibration. As shown in
Multiple methods can be used to produce the composite or vibration dissipating material 10 of the present invention. One method is to extrude the material by pulling a high tensile strength fibrous cloth layer 16 from a supply roll while placing the first and second elastomer layers 12A, 12B on both sides of the woven high tensile strength fibrous cloth 16. A second method of producing the material 10 of the present invention is to mold the first elastomer layer 12A onto the implement 20, then to weave an aramid fiber layer thereover, and then to mold the second elastomer layer 12B thereover.
Alternatively, a cloth layer 16 can be pressured fit to an elastomer layer to form the material 10. Accordingly, the cloth layer 16 can be generally embedded in or held in place by the elastomer layer. The pressured fitting of the reinforcement layer, or fabric layer, 14 to an elastomer preferably results in the reinforcement layer, or fabric layer, 14 being generally interlocked in and/or bonded in position by the elastomer. Thus, the cloth layer can be generally interlocked with the elastomer layer. It is preferable that the high tensile strength cloth generally not be able to slide laterally between the first and second elastomer layers. The cloth layer in the resulting material would be generally fixed in position. One of ordinary skill in the art would realize that the cloth layer 14 in the resulting material would be generally interlocked and/or bonded in position by the elastomer 12A, 12B. Alternatively, the material 10 can be assembled by using adhesive or welding to secure the elastomer layer(s) to the reinforced layer.
It is preferred that the woven high tensile strength fibers are connected to the first and second elastomer layers generally uniformly throughout to provide substantially complete coverage between the first and second thermoset elastomer layers. The cloth layer is generally non energy storing in a direction generally perpendicular to a major material surface. This results in the vibrational energy being generally evenly redistributed throughout the material by the cloth layer. This is due to the high tensile strength fibers transmitting/storing energy unidirectionally along the length of the fiber and generally not storing energy in a direction generally perpendicular to the length of the fiber or perpendicular to a cloth layer formed by the fibers.
In other words, the cloth layer 16 is preferably compliant generally only in a direction generally perpendicular to a major material surface so as to be generally non energy storing in the direction perpendicular to the major material surface and to generally distribute energy parallel to the major material surface and into the first and second elastomer layers. The present invention preferably generally dissipates vibration throughout the material to prevent “bounce back” (e.g., to avoid having a runner's feet absorbed too much vibration during athletics).
In some cases the high tensile fibrous material can be pulped to form an imperforate sheet that may be secured in position between the first and second elastomer layers 12A, 12B. Those of ordinary skill in the art will appreciate from this disclosure that any known method of making composite or vibration dissipating materials can be used to form the material 10.
The covering of the proximal end of an implement 20 by the grip 22 results in reduced vibration transmission and in improved counter balancing of the distal end of the implement 20 by moving the center of mass of the implement 20 closer to the hand of a user (i.e., closer to the proximal end 26). This facilitates the swinging of the implement 20 and can improve sports performance while reducing the fatigue associated with repetitive motion.
A characterizing feature of sleeve 210, as illustrated in
In a broad practice of this invention, sleeve 210 can be a single layer. The material would have the appropriate hardness and vibration dampening characteristics. The outer surface of the material would be tacky having high friction characteristics.
Alternatively, the sleeve 210 could be formed from a two layer laminate where the vibration absorbing material forms the inner layer disposed against the handle, with a separate tacky outer layer made from any suitable high friction material such as a thermoplastic material with polyurethane being one example. Thus, the two layer laminate would have an inner elastomer layer which is characterized by its vibration dampening ability, while the main characteristic of the outer elastomer layer is its tackiness to provide a suitable gripping surface that would resist the tendency for the user's hand to slide off the handle. The provision of the knob 220 also functions both as a stop member to minimize the tendency for the handle to slip from the user's hand and to cooperate in the vibration dampening affect.
Laboratory tests were carried out at a prominent university to evaluate various grips mounted on baseball bats. In the testing, baseball bats with various grips were suspended from the ceiling by a thin thread; this achieves almost a free boundary condition that is needed to determine the true characteristics of the bats. Two standard industrial accelerometers were mounted on a specially fabricated sleeve roughly in positions where the left hand and the right hand would grip the bat. A known force was delivered to the bat with a standard calibrated impact hammer at three positions, one corresponding to the sweet spot, the other two simulating “miss hits” located on the mid-point and shaft of the bat. The time history of the force as well as the accelerations were routed through a signal conditioning device and were connected to a data acquisition device. This was connected to a computer which was used to log the data.
Two series of tests were conducted. In the first test, a control bat (with a standard rubber grip, WORTH Bat-model #C405) was compared to identical bats with several “Sting-Free” grips representing practices of the invention. These “Sting-Free” grips were comprised of two layers of pure silicone with various types of high tensile fibrous material inserted between the two layers of silicone. The types of KEVLAR, a type of aramid fiber that has high tensile strength, used in this test were referenced as follows: “005”, “645”, “120”, “909”. Also, a bat with just a thick layer of silicone but no KEVLAR was tested. With the exception of the thick silicone (which was deemed impractical because of the excessive thickness), the “645” bat showed the best reduction in vibration magnitudes.
The second series of tests were conducted using EASTON Bats (model #BK8) with the “645” KEVLAR in different combinations with silicone layers: The first bat tested was comprised of one bottom layer of silicone with a middle layer of the “645” KEVLAR and one top layer of silicone referred to as “111”. The second bat test was comprised of two bottom layers of silicone with a middle layer of KEVLAR and one top layer of silicone referred to as “211”. The third bat tested was comprised of one bottom layer of silicone with a middle layer of KEVLAR and two top layers of silicone referred to as “112”. The “645” bat with the “111” configuration showed the best reduction in vibration magnitudes.
In order to quantify the effect of this vibration reduction, two criteria were defined: (I) the time it takes for the vibration to dissipate to an imperceptible value; and, (2) the magnitude of vibration in the range of frequencies at which the human hand is most sensitive.
The sting-free grips reduced the vibration in the baseball bats by both quantitative measures. In particular, the “645” KEVLAR in a “111” configuration was the best in vibration reduction. In the case of a baseball bat, the “645” reduced the bat's vibration in about ⅕ the time it took the control rubber grip to do so. The reduction in peak magnitude of vibration ranged from 60% to 80%, depending on the impact location and magnitude.
It was concluded that the “645” KEVLAR grip in a “111” combination reduces the magnitude of sensible vibration by 80% that is induced in a baseball bat when a player hits a ball with it. This was found to be true for a variety of impacts at different locations along the length of the bat. Hence, a person using the “Sting-Free” grips of the invention would clearly experience a considerable reduction in the sting effect (pain) when using the “Sting-free” grip than one would with a standard grip.
In view of the above tests a particularly preferred practice of the invention involves a multilayer laminate having an aramid such as KEVLAR, sandwiched between layers of pure silicone. The above indicated tests show dramatic results with this embodiment of the invention. As also indicated above, however, the laminate could comprise other combinations of layers such as a plurality of bottom layers of silicone or a plurality of top layers of silicone. other variations include a repetitive laminate assembly wherein a vibration dampening layer is innermost with a force dissipating layer against the lower vibration dampening layer and then with a second vibration dampening layer over the force dissipating layer followed by a second force dissipating layer, etc. with the final laminate layer being a gripping layer which could also be made of vibration dampening material. Among the considerations in determining which laminate should be used would be the thickness limitations and the desired vibration dampening properties.
The various layers could have different relative thicknesses. Preferably, the vibration dampening layer, such as layer 222, would be the thickest of the layers. The outermost gripping layer, however, could be of the same thickness as the vibration dampening layer, such as layer 224 shown in
As shown in
In a preferred practice of the invention, as previously discussed, a force dissipating stiffening layer is provided as an intermediate layer of a multilayer laminate where there is at least one inner layer of vibration dampening material and an outer layer of gripping material with the possibility of additional layers of vibration dampening material and force dissipating layers of various thickness. As noted the force dissipating layer could be innermost. The invention may also be practiced where the laminate includes one or more layers in addition to the gripping layer and the stiffening layer and the vibration dampening layer. Such additional layer(s) could be incorporated at any location in the laminate, depending on its intended function (e.g., an adhesive layer, a cushioning layer, etc.).
The force dissipating layer could be incorporated in the laminate in various manners.
The vibration dampening grip cover of this invention could be used for a wide number of implements. Examples of such implements include athletic equipment, hand tools and handlebars. For example, such athletic equipment includes bats, racquets, sticks, javelins, etc. Examples of tools include hammers, screwdrivers, shovels, rakes, brooms, wrenches, pliers, knives, handguns, air hammers, etc. Examples of handlebars include motorcycles, bicycles and various types of steering wheels.
A preferred practice of this invention is to incorporate a force dissipating layer, particularly an aramid, such as KEVLAR fiber, into a composite with at least two elastomers. One elastomer layer would function as a vibration dampening material and the other outer elastomer layer which would function as a gripping layer. The outer elastomer layer could also be a vibration dampening material. Preferably, the outer layer completely covers the composite.
There are an almost infinite number of possible uses for the composite of laminate of this invention. In accordance with the various uses the elastomer layers may have different degrees of hardness, coefficient of friction and dampening of vibration. Similarly, the thicknesses of the various layers could also vary in accordance with the intended use. Examples of ranges of hardness for the inner vibration dampening layer and the outer gripping layer (which may also be a vibration absorbing layer) are 5-70 Durometer Shore A. One of the layers may have a range of 5-20 Durometer Shore A and the other a range of 30-70 Durometer Shore A for either of these layers. The vibration dampening layer could have a hardness of less than 5, and could even be a 000 Durometer reading. The vibration dampening material could be a gel, such as a silicone gel or a gel of any other suitable material. The coefficient of friction as determined by conventional measuring techniques for the tacky and non-porous gripping layer is preferably at least 0.5 and may be in the range of 0.6-1.5. A more preferred range is 0.7-1.2 with a still more preferred range being about 0.8-1. The outer gripping layer, when also used as a vibration dampening layer, could have the same thickness as the inner layer. When used solely as a gripping layer the thickness could be generally the same as the intermediate layer, which might be about 1/20 to ¼ of the thickness of the vibration dampening layer.
The grip cover of this invention could be used with various implements as discussed above. Thus, the handle portion of the implement could be of cylindrical shape with a uniform diameter and smooth outer surface such as the golf club handle 238 shown in
Referring to
As detailed above, the material 10 of the present invention can be used to form gloves or to form panels 305 incorporated into gloves. The preferred cross-section of the glove panels 305 is also shown in
With reference to
Referring to
Referring specifically to
Accordingly, the support structure 817 shown in
Referring again to
The fibers 814 are preferably, but not necessarily, formed of aramid fibers. Referring to
It is preferable that the aramid fibers 818 are formed of a suitable polyamide fiber of high tensile strength with a high resistance to elongation. However, those of ordinary skill in the art will appreciate from this disclosure that any aramid fiber suitable to channel vibration can be used to form the support structure 817 without departing from scope of the present invention. Additionally, those of ordinary skill in the art will appreciate from this disclosure that loose aramid fibers or chopped aramid fibers can be used to form the support structure 817 without departing from the scope of the present invention. The aramid fibers may also be formed of fiberglass or the like.
When the aramid fibers 818 are woven to form the cloth 816, it is preferable that the cloth 816 include at least some floating aramid fibers 818. That is, it is preferable that at least some of the plurality of aramid fibers 818 are able to move relative to the remaining aramid fibers 818 of the cloth 816. This movement of some of the aramid fibers 818 relative to the remaining fibers of the cloth converts vibrational energy to heat energy.
With reference to
In the situation where the support structure 917 is formed by a second elastomer layer, the two elastomer layers can be secured together via an adhesive layer, discreet adhesive locations, or using any other suitable method to secure the layers together. Regardless of the material used to form the support structure 917, the support structure is preferably located and configured to support the first elastomer layer (see
It is preferred that the material 910 have a single contiguous elastomer body 912. Referring to
Referring to
The fibers 914 are preferably, but not necessarily, formed of aramid fibers. However, the fibers can be formed from any one or combination of the following: bamboo, glass, metal, elastomer, polymer, ceramics, corn husks, and/or any other renewable resource. By using fibers from renewable resources, production costs can be reduced and the environmental friendliness of the present invention can be increased.
Particles 915 can be located in either an elastomer layer 912, 912A, and/or 912B and/or in the support structure 915. The particles 915 increase the vibration absorption of the material of the present invention. The particles 915 can be formed of pieces of glass, polymer, elastomer, chopped aramid, ceramic, chopped fibers, sand, gel, foam, metal, mineral, glass beads, or the like. Gel particles 915 provide excellent vibration dampening due their low durometer rating. One exemplary gel that is suitable for use the present invention is silicone gel. However, any suitable gel can be used without departing from the present invention.
In addition to use with implements, sleeves, covers, and the like described above, the material can be used as an athletic tape, padding, bracing material, or the like (as shown in
When the material of the present invention is used to form athletic tape, that athletic tape provides a controlled support for a portion of the person's body. The athletic tape includes a tape body 64 that is preferably stretchable along a longitudinal axis 48 (or stretch axis 50) from a first position to a second position, in which the tape body 64 is elongated by a predetermined amount relative to the first position.
As described below, the configuration of the support structure 17 within the vibration absorbing layer 12 allows the predetermined amount of elongation to be generally fixed so that the athletic tape provides a controlled support that allows limited movement before applying a brake on further movement of the wrapped portion of a person's body. This facilitates movement of a wrapped joint while simultaneously dissipating and absorbing vibration to allow superior comfort and performance as compared to that experienced with conventional athletic tape. While the predetermined amount of elongation can be set to any value, it is preferably less than twenty (20%) percent. The predetermined amount of elongation is more preferably less than two (2%) percent. However, depending on the application any amount of elongation can be used with the material 10 of the present invention.
The tape body 64 preferably includes a first elastomer layer 12 that defines a tape length 66, as measured along the longitudinal axis 48, of the tape body 64. The support structure 17 is preferably disposed within the elastomer layer 12 generally along the longitudinal axis 48 in an at least partially non linear fashion while the tape body is in the first position so that a length of the support structure 17, as measured along a surface thereof, is greater than the tape length 66 of the first elastomer layer 12. It is preferred, by not necessary, that the support structure 17 (or ribbon material) is positioned in a generally sinusoidal fashion within the elastomer layer 12 while the tape body 64 is in the first position. However, the support structure 17 can be positioned in an irregular fashion without departing from the scope of the present invention. As described above, the support structure 17 and/or the elastomer layer 12 can include particles, fibers, or the like (as shown in
Referring to
Referring to
As detailed above, the support structure 17 and/or the elastomer layer 12 may include a plurality of particles therein. Such particles may include any one or combination of gel particles, sand particles, glass beads, chopped fibers, metal particles, foam particles, sand, or any other particle in parting desirable vibration dissipation characteristics to the material 10.
Referring to
Referring again to
The first elastomer layer 712 defines a material length 772, as measured along the stretch axis 750 of the material body 770. The support structure 717 is preferably disposed within the elastomer layer 712 generally along the stretch axis 750 in an at least partially non linear fashion while the material body 770 is in the first position so that a length of the support structure, as measured along the surface thereof, is greater than the material length 772 of the first elastomer layer. When the material body 770 is elongated into the second position, the support structure 717 is at least partially straightened so that the support structure is more linear, relative to when the material body 770 is in the first position.
The support structure 717 is preferably positioned in a sinusoidal fashion within any of the materials 710 of the present invention. The support structure 717 or ribbon may also be positioned in the form of a triangular wave, square wave, or an irregular fashion without departing from the scope of the present invention.
Any of the materials of the present invention may be formed with an elastomer layer 712 formed by silicone or any other suitable material. Depending upon the application, the vibration absorbing material 712 may be a thermoset and/or may be free of voids therein.
Any of the embodiments of the material 710 can be used as an implement cover, grip, athletic tape, an all purpose material, a brace, and/or padding. When the material 710 of the present invention is used as part of a padding, the padding includes a padding body 774 that is elongateable along the stretch axis from a first position to a second position, in which the padding body 774 is elongated by a predetermined amount relative to the first position. The padding includes a first elastomer layer 712 which defines a padding length 776, as measured along the stretch axis 750 of the padding body 774.
The support structure 717 is disposed within the elastomer layer 712 generally along the stretch axis 750 in an at least partially non linear fashion while the padding body 774 is in the first position so that a length of the support structure 717, is measured along a surface thereof, is greater than the padding length 776 of the first elastomer layer 712. When the padding body 774 is elongated into the second position, the support structure 717 is at least partially straightened so that the support structure is more linear, relative to when the padding body 774 is in the first position. The straightening of the support structure 717 causes energy to be dissipated and generally prevents further elongation of the elastomer layer along the stretch axis 750 past the second position.
When the materials 710 of the present invention are incorporated as part of a brace, the brace provides a controlled support for a wrapped portion of a person's body. The brace includes a brace body 778 that is elongateable along the stretch axis 750 from a first position to a second position, in which the brace body 778 is elongated by a predetermined amount relative to the first position. The brace body includes a first elastomer layer 712 that defines a brace length 780, as measured along the stretch axis 750, of the brace body 778.
The support structure 717 is preferably disposed within the elastomer layer generally along the stretch axis 750 in an at least partially non linear fashion while the brace body 778 is in the first position so that a length of the support structure 717, as measured along a surface thereof, is greater than the brace length 780 of the first elastomer layer 712. When the brace body 778 is stretched into the second position, the support structure 717 is at least partially straightened so that the support structure 717 is more linear, relative to when the brace body 778 is in the first position. The straightening of the support structure 717 causes energy to be dissipated and preferably generally prevents further elongation of the elastomer layer 712 along the stretch axis past the second position. Those ordinarily skilled in the art will appreciate that any of the materials 710 of the present invention may be formed into a one piece brace that provides a controlled support as described above without departing from the scope of the present invention.
Referring to
Referring to
Any of the materials 710 of the present invention can be used in conjunction with additional layers of rigid or flexible materials without departing from the scope of the present invention. For example, the materials 710 of the present invention may be used with a hard shell outer layer which is designed to dissipate impact energy over the entire material 710 prior to the material 710 deforming to dissipate energy. One type of rigid material that can be used in combination with the materials 710 of the present invention is molded foam. Molded foam layers preferably include multiple flex seams that allow portions of the foam layer to at least partially move relative to each other even though the overall foam layer is a single body of material. This is ideal for turning an impact force into a more general blunt force that is spread over a larger area of the material 710. Alternatively, individual foam pieces, buttons, rigid squares, or the like can be directly attached to an outer surface of any of the materials 710 of the present invention. Alternatively, such foam pieces, buttons, rigid squares, or the like can be attached to a flexible layer or fabric that will dissipate received impact energy over the length of the fabric fibers prior to the dissipation of energy by the material 710.
Alternately, rather than using aramid layers, other fibers could be used, including high tensile strength fibers.
While other high tensile strength materials could be used, aramids with a tensile modulus of between 70 and 140 GPa are preferred, and nylons such as those with a tensile strength of between 6,000 and 24,000 psi are also preferred. Other material layers and fibers could substitute for the aramid layers 1010, 1012; in particular, low tensile strength fibers could be combined with higher tensile strength fibers to yield layers 1010, 1012 that would be suitable to stabilize and contain the elastomeric layer 1020. For example, cotton, kenaf, hemp, flax, jute, and sisal could be combined with certain combinations of high tensile strength fibers to form the supportive layers 1010, 1012.
In use, the first and second aramid material layers 1010, 1012 are preferably coated with a bonding layer 1010a, 1010b, 1012a, 1012b, preferably of the same material as the elastomeric material that facilitates bonding between the aramid layers 1010, 1012 and the elastomeric layer 1020, although these bonding layers are not required. Further, although equal amounts of the bonding layers 1010a, 1010b, 1012a, 1012b are shown on either side of the aramid layers 1010, 1012, the bonding layers 1010a, 1010b, 1012a, 1012b need not be evenly distributed over the aramid layers 1010, 1012.
The applicant has observed that the aramid layers 1010, 1012 distribute impact and vibration over a larger surface area of the elastomeric layer 1020. This finding has suggested using the material in heavier impact applications, such as using it as a motor mount 1030 or flooring 1035, 1037, since the aramid layers 1010, 1012 will discourage displacement of the elastomeric layer 1020, while still absorbing much of the vibration in those applications. This property could be useful in many of the above-noted applications, and in particular in impact absorbing padding, packaging, electronics padding, noise reducing panels, tape, carpet padding, and floor padding.
In use, this material can be used as a flooring 1037, as shown in
In use as a motor mount, the material is formed as a cylinder 1040, in which the aramid layer 1010 forms an outer cylinder with an elastomer 1020 located therebetween. This cylinder 1040 is closed on itself (by gluing or welding) to form the toroidal shaped shock absorber 1050, which could be used as a motor mount.
The foam layer 1110 is preferably rigid and inflexible, although softer foam layers may be used. The rigid foam layers 1110 present a problem in that many impact-resistant applications require flexible material, i.e., paintball padding and armor that can flex around a person's body. The applicant solved this problem by forming narrow areas of weakness 1111 in the foam layer. These areas can be formed by cutting, stamping, or forming the area of predetermined weakness, but in any event, the allow for the foam layer 1110 to bend at these areas 1111. Various shapes of the areas of predetermined weakness could be used depending on the needed flexibility. As shown, parallel, hexagonal, and herringbone (diamond) areas are presently preferred.
Finally, the applicant has found that a fourth rigid layer comprising plastic, foam, or metal, could be added over the foam/aramid/elastomer to further dissipate impact energy.
Any of the above-mentioned layers could be soaked in, embedded in, encapsulated by, or otherwise distributed with a resistive fluid. Preferably, the resistive fluid layer is separated from the wearer/holder by at least one of the elastomer layers to minimize the direct transmission of impact to the wearer/holder.
Body armor is a frequently cited use of resistive fluids—such an application would work well with all of the vibration-reducing materials described herein because the vibration-reducing material would further protect the wearer from damaging vibration from an impact and puncture.
It is recognized by those skilled in the art, that changes may be made to the above-described embodiments of the invention without departing from the broad inventive concept thereof. For example, the material 10 may include additional layers (e.g., five or more layers) without departing from the scope of the claimed present invention. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but is intended to cover all modifications which are within the spirit and scope of the invention as defined by the appended claims and/or shown in the attached drawings.
Claims
1. A material adapted to regulate vibration, comprising:
- first and second elastomer layers; and
- a cloth layer disposed between and generally separating the first and second elastomer layers, the cloth layer comprising a resistive fluid.
2. A composite material adapted to regulate vibration, the composite material having three generally independent and separate layers, comprising:
- first and second elastomer layers; and
- a cloth layer disposed between and generally separating the first and second elastomer layers, the cloth layer comprising a resistive fluid.
3. A vibration absorbing material, comprising:
- a first elastomeric layer of vibration absorbing material;
- a second elastomeric layer which includes a material disposed on the first elastomeric layer; and
- a third elastomeric layer disposed on the second elastomeric layer;
- wherein at least one of the elastomeric layers comprises a resistive fluid.
4. A vibration absorbing material comprising:
- a first elastomeric layer of vibration absorbing material;
- a second elastomeric layer of vibration absorbing material;
- wherein at least one of the elastomeric layers comprises a resistive fluid.
5. A material that regulates vibration by distributing and partially dissipating vibration exerted thereon, the material comprising:
- an elastomer layer; and
- a support structure penetrated by and embedded on and/or within the elastomer layer, the support structure comprising a resistive fluid and supporting the elastomer layer.
6. A material adapted to regulate vibration by distributing and partially dissipating vibration exerted thereon, the material comprising:
- a elastomer layer; and
- a support structure penetrated by and embedded on and/or within the elastomer layer, the support structure comprising a resistive fluid and supporting the elastomer layer, the support structure having a first plurality of particles therein.
7. A material adapted to regulate vibration by distributing and partially dissipating vibration exerted thereon, the material comprising:
- a first elastomer layer; and
- a support structure comprising a resistive fluid and formed by a second elastomer layer, the support structure being located and configured to support the first elastomer layer.
8. An athletic tape for wrapping a portion of a person's body, the athletic tape having a longitudinal axis and being adapted to provide a controlled support for the portion of the person's body, the athletic tape comprising:
- a tape body being stretchable along the longitudinal axis from a first position to a second position, in which the tape body is elongated by a predetermined amount relative to the first position, the tape body comprising: a first elastomer layer defining a tape length, as measured along the longitudinal axis, of the tape body; a support structure disposed within the elastomer layer generally along the longitudinal axis in an at least partially non linear fashion while the tape body is in the first position so that a length of the support structure, as measured along a surface thereof, is greater than the tape length of the first elastomer layer, the support structure comprising a resistive fluid; and wherein when the tape body is stretched into the second position, the support structure is at least partially straightened so that the support structure is more linear, relative to when the tape body is in the first position, the straightening of the support structure causing energy to be dissipated and generally preventing further elongation of the elastomer layer along the longitudinal axis past the second position, the support structure comprising a plurality of fibers. ***any of the layers has a resistive fluid
9. A vibration-reducing material comprising:
- first and second high tensile strength material layers, wherein the high tensile strength material layers distribute vibration to facilitate vibration dampening; and
- an elastomeric layer configured to absorb vibration and impact energy, located substantially between the first and second high tensile strength material layers;
- wherein at least one of the layers comprises a resistive fluid.
10. The material of claim 9, wherein the high tensile strength material has a tensile strength between 6,000 and 24,000 psi.
11. A vibration-reducing material comprising:
- a foam material layer;
- a material layer that distributes vibration to facilitate vibration dampening; and
- a elastomeric material layer configured to absorb vibration;
- wherein at least one of the layers comprises a resistive fluid.
12. A vibration-reducing material comprising:
- a foam material layer;
- a high tensile strength material layer that distributes vibration to facilitate vibration dampening; and
- a elastomeric material layer configured to absorb vibration;
- wherein at least one of the layers comprises a resistive fluid.
Type: Application
Filed: Dec 8, 2006
Publication Date: Jun 28, 2007
Applicant: Sting Free Company (Berwyn, PA)
Inventors: Robert Vito (Berwyn, PA), Carmen DiMario (West Chester, PA), Thomas Falone (Mickleton, NJ)
Application Number: 11/635,939
International Classification: D03D 15/00 (20060101);