Bi-directional Cam Buckle
A bi-directional cam buckle is provided. The invention allows selectable placement of a bi-directional buckle across a strap for secure resistance of bi-directional load pulls. The bi-directional cam device can be threaded in anti-reverse, dual cam, or single cam configurations.
The present invention relates to a bi-directional cam buckle. More particularly, the present invention relates to a dual cam buckle device with bi-directional resistance for opposing a load pull from either direction across the cam device. The bi-directional cam device of the present invention has application to resistance training for fitness, among other uses.
BACKGROUND OF THE INVENTIONIn general, strength training refers to muscle training that uses a resistance force in opposition to the force generated from a muscle contraction. Resistance training is a specific type of strength training, where the opposing force is provided by elastic, hydraulic, or mechanical tension. The resistance force could be a force opposing muscular action of bending, stretching, pushing, or squeezing an object. However, the key aspect of resistance training is the opposition of an elastic, changing force against the muscle. The resistance exercise is isotonic in that the muscle is engaged in relative movement against the opposing force.
Resistance training is a well-known aspect of personal exercise and fitness programs. Through resistance training, a person can gradually and progressively overload the musculoskeletal system so it gets stronger. Resistance training can strengthen and tone muscles and increase bone mass. Properly performed, resistance training offers significant functional benefits and is an efficient method of developing greater muscle mass or muscle tone. One particular aspect of resistance training that is beneficial is that resistance training exercises generally allow a full range of motion. This is helpful because certain muscles are overloaded more efficiently at specific joint angles where the muscle is worked. It is therefore important in resistance training that the equipment used by the person by properly sized or positioned for optimal alignment with the person's skeletal size and joint alignment.
One method of resistance training is to attach an exercise elastic to a fixed object and exert repetitive motions that stretch the elastic away from the fixed object. However, as discussed above, in order to maximize the efficiency of a training workout, the equipment must be properly positioned for the individual person. One way to adjust the location of the attachment point for the elastic to the fixed object is to use a sliding cam-type buckle on a strap that is secured to a fixed object. The cam-type buckle can be slid across the strap and then locked in place through a gripping motion of the buckle's teeth against the strap.
U.S. Pat. No. 7,343,650 (Baldwin et al.) discloses a child restraint system that employs a dual cam buckle device with teeth for gripping a strap. Webbing can be passed through the buckle in a single direction and the gripping teeth act to prevent the webbing from sliding backwards against the direction of the inserted webbing. The buckle is fixedly attached to the child restraint unit, which is a car seat. By squeezing the handles of the opposing cams, the opposing teeth of the buckle can be opened and the webbing can be loosened opposite the direction of insertion. The device allows unidirectional resistance of movement of the car seat straps and thereby safely encloses the child within the child restraint seat.
U.S. Pat. No. 6,863,197 (Dirlam et al.) discloses a garment hanger with improved garment securing grips. The garment securing grip has a cam-type buckle that opens to allow a unidirectional insertion of clothing into the hanger clip. When closed, the gripping teeth of the hanger clip engage against the clothing and the rear clip wall, thereby preventing the clothing from falling out of the hanger clip. The cam-type buckle of this device is comprised of a single cam. U.S. Pat. No. 2,488,709 (Colwell) discloses a spring activated dual-cam clip for a hanger. The hanger clip allows clothing to be inserted into the clip and secures the clothing within the clip by the spring-activated engagement of the opposing cam teeth against the inserted clothing.
These prior art cam gripping devices are inadequate because, among other things, they do not provide for a bi-directional gripping action. The need to provide ultimate adjustability to any cam-locking buckle used to secure the elastic to the fixed object demands that the buckle be capable of withstanding bi-directional pull. The bi-directional features of a buckle are also necessary if the person is to employ a wide variety of exercise during the routine. Pull-down exercises would require the buckle to resist downward movement, while pull-up exercises would require the buckle to resist upward movement. The prior art devices do not allow this type of bi-directional movement without physically detaching and reversing the single-direction locking cam buckle. Thus, there exists a need in the art for a simple, easily adjustable bi-directional locking device that can be used to secure resistance training equipment to fixed objects while allowing a full range of exercise motion and points of attachment customized to the individual person.
SUMMARY OF THE INVENTIONIt is an object of the present invention to provide a bi-directional cam buckle device.
It is a further object of the present invention to provide a resistance training device that can allow a full range of exercise motions customized to an individual person.
It is further desirable to provide a bi-directional resistance training device that can be adapted for placement across a door and that is easily portable and lightweight.
It is further desirable to provide a bi-directional resistance training device that is easy to use and inexpensive to manufacture.
It is a further object of the present invention to provide a bi-directional cam buckle that can be selectively positioned in conjunction with a fixed object.
It is yet another object of the present invention to provide a selectively moveable device that can engage a strap and oppose bi-directional pull without slippage across the strap.
It is further desirable to provide a single bi-directional cam device selectively configurable to anti-reverse, dual cam and single cam positions.
It is still a further object of the present invention to provide a tie-down system using a bi-directional cam buckle for securing cargo loads to a vehicle.
The above-described features and advantages of the present invention, as well as additional features and advantages, will be set forth or will become more fully apparent in the description that follows. Furthermore, the features and advantages of the invention may be learned by the practice of the invention, or will be obvious to one skilled in the art after referring to the invention description, as set forth hereinafter.
Various embodiments of the present invention are shown and described in reference to the numbered drawings wherein:
It will be appreciated that the drawings are illustrative and not limiting of the scope of the invention which is defined by the appended claims. The embodiments shown accomplish various aspects and objects of the invention. It is appreciated that it is not possible to clearly show each element and aspect of the invention in a single FIGURE, and as such, multiple figures are presented to separately illustrate the various details of the invention in greater clarity.
DETAILED DESCRIPTION OF THE INVENTIONThe present invention relates to a bi-directional cam buckle. The present invention allows more efficient isotonic athletic conditioning customized to the person's skeletal size. The present invention also allows a wide variety of training exercise to be performed through selective movement and locking of the bi-directional cam device (5) across a support strap (35). Thus, the present invention is a useful advancement in the athletic training art. Further, the bi-directional cam-type device of the present invention has application across a number of different arts where resistance to a bi-directional load pull is necessary, such as cargo netting and cargo tie-downs.
It is understood that the terminology used herein is used for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention. It is also understood that, as used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural reference, unless the context clearly dictates otherwise.
Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which this invention belongs. While various methods, compositions, and materials of the present invention are described herein, any methods and materials similar or equivalent to those described herein can by used in the practice or testing of the present invention. All references cited herein are incorporated by reference in their entirety.
Referring to the accompanying drawings, there is illustrated a bi-directional cam-type device (5) into which a strap (35) or other type of webbing can be threaded. The bi-directional cam device (5) has two opposing plates (10) which form the lateral support structure for the device. Opposing plates (10) are spaced a sufficient distance apart such that the width of strap (35) can be accommodated. Opposing plates (10) are kept apart in a fixed position by connecting rod (15), friction bars (20), and cam-type engagers (25), whose respective functions are described below.
In addition to acting as a spacer between opposing plates (10), connecting rod (15) may also serve as the attachment point between bi-directional cam device (5) and any external equipment or items intended for use with the device. For example, if bi-directional cam device (5) is to be used in a sheathed elastic resistance trainer system, connecting rod (15) would receive the attachment clip from the end of the sheathed elastic tubing which would then be pulled by the person in a direction against the gripping force of bi-directional cam device (5).
Friction bars (20) are also placed between opposing plates (10) and have longitudinal slots (22) formed into them for providing an increased frictional surface against which strap (35) can be pressed by cam-type engagers (25). The cam-type engager (25) has a friction face (27), pivot rod (29), spring (31), and pressure plate (33). The rotational axis on which pivot rod (29) turns is eccentrically positioned such that the length of the arc created by rotating the edge of pressure plate (33) about pivot rod (29) is greater than the length of the resulting arc movement of friction face (27). Spring (31) is wrapped about pivot rod (29) with opposing ends placed against the back of pressure plate (33) and the inner side of friction bar (20) such that friction face (27) of cam-type engager (25) is biased in a closed position against longitudinal slots (22) of friction bar (20). Pivot rod receiving holes (12) are drilled into opposing plates (10) for receiving the ends of pivot rods (29) such that cam-type engagers (25) can be fixedly placed between opposing plates (10) while allowing rotational movement of cam-type engagers (25) about pivot rods (29). Together, connecting rod (15), pivot rods (29), and friction bars (20) provide lateral support for opposing plates (10) and function with opposing plates (10) as the frame of the bi-directional cam device (5).
It is contemplated that pressures plates (33) will be squeezed or pinched together against the stored energy of springs (31) toward the direction of connecting rod (15) by the simple action of finger pressure. Accordingly, the ratio of the radial length defined by the distance from the outer edge of pressure plate (33) to the center of the axis of pivot rod (29) compared to the radial length defined by the distance from the outer edge of friction face (27) to the center of the axis of pivot rod (29) is 1:1, preferrably 3:2, and most preferably 2:1. The parts comprising bi-directional cam device (5) can be made of any type of rigid, strong material such as steel or composite plastics or may be cast depending on the specific application for which the device is used. Preferably, bi-directional cam device (5) and all component parts thereof are made of stainless steel.
A further inventive aspect of bi-directional cam device (5) of the present invention is the unique placement of friction bars (20) from the distal ends of pressure plates (33). It is contemplated that pressure plates (33) of cam-type engagers (25) will be simultaneously or independently squeezed through application of finger pressure. To assist the user in holding cam-type engagers (25) open against the closing action of springs (31), connecting rod (15) is located an ergonomic distance from the distal ends of pressure plates (33) such that the first knuckle of the user's thumb and forefinger will be located directly opposite each other across connecting rod (15). In this manner, the user can comfortably hold cam-type engagers (25) in an open position while moving bi-directional cam device (5) across strap (35) by using the fingers' knuckle joints to naturally locate and squeeze against connecting rod (15). It is preferred that the distal ends of pressure plates (33) be located between 10 and 20 mm from the central axis of connecting rod (15) when measured in the maximum open position, most preferably 15 mm.
To thread a strap or webbing (35) into bi-directional cam device (5), pressure plate (33) is squeezed toward connecting rod (15) such that friction face (27) of cam-type engager (25) is lifted off of the longitudinal slots (22) of friction bar (20). The webbing is then inserted into the gap between friction face (27) and friction bar (20). Pressure plate (33) is then released and the stored energy of spring (31) biases friction face (27) into a closed position thereby pressing webbing (35) against friction bar (20). Friction face (27) of cam-type engager (25) is formed with an angled face that cannot completely move inward across friction bar (20) without striking the bar. In this way, pulling the webbing further into bi-directional cam device (5) after pressure plate (33) is released will act to jam friction face (27) tighter and tighter against friction bar (20) thereby completely arresting any further inward movement of the webbing. It will be appreciated by those skilled in the art that friction face (27) of cam-type engager (25) and friction bar (20) can be modified to accommodate curvilinear straps, such as ropes.
It is central to the purpose of the present invention that cam-type engagers (25) are positioned in opposite bias relative to each other such that a strap or webbing threaded through bi-directional cam device (5) and across both friction faces (27) can be effectively locked in place against bi-directional pull on either end of the webbing. In this way, the bi-directional cam device of the present invention can function as an anti-reverse cam buckle. The bi-directional buckle is further designed for additional versatility in that it can also act as either a single or dual cam buckle. By leaving the end of bi-directional cam device (5) that is distal from connecting rod (15) and between opposing plates (10) open, webbing can be threaded across friction face (27) of cam-type engager (25) and out the bottom of bi-directional cam device (5) without crossing the second friction face. In this manner, bi-directional cam device (5) can act as a single cam buckle, if one strap is threaded, or a dual cam buckle if two straps are threaded into the sides and out the bottom of the device.
Another configuration of the present invention is to affix the ends of opposing plates (10) opposite friction bars (20) to a face bracket (70). The face bracket (70) could the be mounted using mounting hole (72) or welded to any equipment or device desired to be selectively positioned across strap or webbing (35). This would eliminate the need to install connecting rod (15). In the event that face bracket (70) is used in place of connecting rod (15), the width of opposing plates (10) should be configured such that both pressure plates (33) could be biased open in a convenient manner by positioning the user's fingers across the width of the plates.
Yet another novel configuration of the present invention is utilizing a single friction bar (20) instead of two friction bars. This unique arrangement is accomplished by positioning cam-type engagers (25) and their respective pivot rods (29) such that the friction faces (27) of each engager strikes the same single friction bar. The friction bar (20) must be positioned equidistant from each pivot rod axis and must further have longitudinal slots (22) positioned to match the incoming friction faces (27) of each cam-type engager (25). This particular configuration is advantageous due to its lower construction costs and more slim design. Further, there is less rotational disruption to the fixed position of longitudinal slots (22) on friction bar (20) when bi-directional cam device (5) is used in anti-reverse mode because the opposing rotational forces balance out across friction bar (20). Like the dual friction bar model, the single friction bar version of the present invention can be threaded in anti-reverse, dual cam, or single cam patterns. The single friction bar configuration can also employ mounting bracket (70) for more permanent and secure attachment of equipment or devices to bi-directional cam device (5).
The bi-directional cam device of the present invention can be used as a bi-directional resistance trainer through the application of an isotonic resistance exercise device such as a sheathed elastic attached to a handle. It will be appreciated by those of skill in the art that the bi-directional resistance trainer could employ unsheathed elastics, springs, weights, etc. For this specific application, webbing (35) is provided with mounting holes (50) on both ends of a piece of webbing. The webbing (35) is threaded into bi-directional cam device (5) in an anti-reverse configuration and the webbing is stretched tight across a flat surface of a heavy or immovable object such as a wall. Surface attachments such as screws or rivets are placed through mounting holes (50) to fixedly attach the webbing and threaded bi-directional cam device (5) to the surface of the heavy or immovable object. A clip (64) is used to attach the end of sheathed elastic (60) to connecting rod (15) of bi-directional cam device (5). It is preferred that SLASTIX® brand sheathed elastics be used because of their versatile tensile strengths, rugged construction, and safety features. A handle (62) is attached to the opposite end of sheathed elastic (60). The person wishing to exercise can pinch together the pressure plates (33) of bi-directional cam device (5) and selectively position the bi-directional cam device vertically or horizontally, depending on the orientation of strap (35), to pull handle (62) either down or up depending on the desired muscle group to be worked. The bi-directional capability of bi-directional cam device (5) allows instantaneous changing of the routine such that the exerciser can switch between sets of pull-downs and pull-ups against the resistance force of the sheathed elastic (60). Different tensile strengths of sheathed elastics (60) can be easily added between clip (64) and handle (62) to increase the difficulty of the exercise routine. Thus, the bi-directional capability of the present resistance training device allows for simple adjustment of the bi-directional cam device to account for specific muscle groups, the skeletal size of the person exercising, as well fine-tuning the angle of exercise to promote a more efficient work out of joint angles.
Yet another embodiment of the present invention is a bi-directional resistance trainer adapted for attachment to a door (40). Instead of using mounting holes (50) to attach the webbing (35) and bi-directional cam device (5) to a wall using screws or rivets, a fairly permanent arrangement, webbing (35) can be attached to door brackets (45) and stretched tight across a face of a door (40). There are a number of possible methods of attaching webbing (35) to door brackets (45), all well known to practitioners in the art. It is preferred that at least one of the door brackets (45) be adjustably attachable to webbing (35) such that the arrangement can be easily adapted to doors of various heights. Door brackets (45) are preferably configured with 90° angles such that the brackets will remain positioned on the top and bottom of door (40) when the webbing is tightened. Alternatively, there could be a single door bracket (45) permanently fixed to webbing (35) with a short end and a long end of webbing extending therefrom. The long end of the webbing could be wrapped up and around the top of the door and adjustably connected with the short end of the webbing using any number of connection methods known in the art, such as a locking buckle. In this single-bracket configuration, the door can easily be opened and closed without removing the webbing because there is no top bracket to interfere with the top door jam. A further contemplated configuration for the door system is to place extra folds of material along a portion of the webbing such that the extra folds will hit the top of the door jam and thereby prevent full rotation of the webbing around the door when the door is closed. This configuration is preferable because there is less likelihood the door will be marked or scuffed from the folded or bunched webbing material compared to the use of brackets (45). Once webbing (35) is cinched tight, a sheathed elastic (60) can be attached to connecting rod (15) of bi-directional cam device (5) using clip (64). As with the wall-type mount, the bi-directional features of the present invention can be employed by selectively positioning bi-directional cam device (5) across webbing (35) stretched across door (40). This configuration provides an extremely convenient and portable exercise system specifically adapted to travelers, office workers, or casual home users, although these examples are not limiting.
Yet another embodiment of the present invention is a bi-directional tie-down system for securing cargo to a vehicle.
Yet another embodiment of the present invention is a system of cargo netting using the bi-directional cam devices disclosed herein.
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.
Claims
1-3. (canceled)
4. A device for resisting a bi-directional load pull, the device comprising:
- a housing;
- dual cam-type engagers secured within said housing and positioned in opposite bias, said engagers having a friction surface and being positionable between an open and a closed position; and
- means for securely holding a strap threaded into said device against said engagers when said engagers are in a closed position.
5. The device of claim 4, wherein said housing includes first and second plates spaced a sufficient distance apart such that said strap can be threaded between said plates;
- wherein said engagers include pivot rods secured to said first and second plates such that said engagers can be rotatably positioned around said pivot rods between said open and closed positions.
6. The device of claim 5, wherein said engagers include a pressure plate having an end distal to said friction surface.
7. The device of claim 6, wherein the ratio of the radial length defined by the distance from said distal end of said pressure plate to the center of said pivot rod compared to the radial length defined by the distance from said friction face to said pivot rod is 1:1.
8. The device of claim 7, wherein said ratio is 3:2.
9. The device of claim 7, wherein said ratio is 2:1.
10. The device of claim 6 further comprising a connecting rod positioned between said plates.
11. The device of claim 10, wherein the distance between said connecting rod and said distal ends of said pressure plates is between 10 and 20 mm.
12. The device of claim 11 further comprising springs wrapped around said pivot rods, said springs biasing said engagers into a closed position.
13. A method for producing a device for resisting a bi-directional load pull, comprising:
- providing a housing adapted to receive cam-type engagers, said engagers being positioned in opposite bias, having a friction surface, and being configured to pivotably move between open and closed positions within said housing; and
- providing means for securely holding a strap threaded into said device against said engagers when said engagers are in a closed position, such that said strap is secured against movement relative to said device when pulled in either direction across said engagers.
14. An exercise system comprising:
- a bi-directional cam device comprising a housing; dual cam-type engagers secured within said housing and positioned in opposite bias, said engagers having a friction surface and being positionable between an open and a closed position; and means for securely holding a strap threaded into said device against said engagers when said engagers are in a closed position;
- a strap comprising means for securely affixing said strap to a non-moving surface, said strap being configured for slideable placement across said engagers of said bi-directional cam device when said engagers are in an open position;
- a resisting element configured for attachment to said bi-directional cam device; and
- a handle attached to said resisting element.
15. The exercise system of claim 14, wherein said resisting element is an elastic member that provides a changing force against muscular pull when said engagers of said bi-directional cam device are in a closed position agains said strap.
16. A method for securing cargo, comprising:
- providing a plurality of housings, each housing adapted to receive cam-type engagers, said engagers being positioned in opposite bias, having a friction surface, and being configured to pivotably move between open and closed positions within said housing;
- providing means for securely holding straps threaded into said housings against said engagers when said engagers are in a closed position, such that said straps are secured against movement relative to said housings when pulled in either direction across said engagers;
- placing said straps across a cargo load;
- threading said straps into said housings and across said engagers; and
- cinching said straps across said engagers to secure said cargo.
17. The method of claim 16, further comprising the step of forming a netting of said straps using a plurality of housings across which said straps are selectively placed and selectively cinched.
Type: Application
Filed: Dec 3, 2009
Publication Date: Jun 3, 2010
Inventor: Shon L. Harker (Syracuse, UT)
Application Number: 12/630,425
International Classification: A63B 21/00 (20060101); B61D 45/00 (20060101); A44B 11/02 (20060101);
