Adjustable linear friction device
An adjustable linear friction device for exercising the forearm, wrist and hand, comprising: a disc rotatably mounted on a housing, with a circumferential edge and opposed faces; a friction band extending between an anchor and biasing means, the friction band disposed against the circumferential edge of the disc; a shaft extending outwardly from the opposed faces, with handles on the shaft for rotating the shaft to effect rotation of the disc. Rotating the disc in a first direction results in a first normal friction between the friction band and the circumferential edge, and rotating the disc in a second and opposite direction results in a second, different normal friction. The device can be used to exercise the forearm and wrist joint in supination/pronation, extension/flexion, and radial/ulnar deviation motions through the full range of motion.
The present invention relates to exercise devices for working the forearm, wrist and hand muscles, and more particularly to such exercise devices employing frictional resistance.
BACKGROUND OF THE INVENTIONVarious sports activities require a certain degree of arm/wrist strength and range of motion, particularly where an object is manipulated by the player's hands (e.g. a baseball bat). However, it is sometimes the case that a player does not possess the desired strength and range of motion. Participating in the particular sports activity while possessing inadequate strength or range of motion can sometimes result in an injury to the wrist muscles, which may entail a considerable recovery period if full recovery is even possible.
The wrist and associated muscles are involved in six primary forms of motion: forearm supination and pronation; wrist flexion and extension; and radiavulnar deviation:
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- Forearm supination/pronation: Supination is forearm movement that causes the hand to be positioned palm-up, while pronation is forearm movement that causes the hand to be positioned palm-down. In supination/pronation, the axis of rotation passes through the centres of both the radial and ulnar heads, and is therefore not parallel to the longitudinal axis of the forearm, pronation and supination resulting from rotation of the radius about the ulna.
- Wrist flexion/extension: Flexion is a downward/inward movement at the wrist that results in the palm facing inward toward the individual, while extension is an upward movement at the wrist that results in the palm facing outward. The axis of rotation passes through the centre of the capitate bone.
- Radial/ulnar deviation: Deviation involves side-to-side movement of the hand at the wrist. Radial deviation (also known as abduction) is a rotation of the hand toward the thumb, while ulnar deviation (also known as adduction) is a rotation away from the thumb. The axis of rotation is a line perpendicular to the plane of the palm through the intersection of the capitate and lunate bones.
As inadequate strength or range of motion can result in serious injury, and the wrist is involved in a number of different forms of motion, it is therefore desirable to exercise the relevant muscles in such a way that the muscles are strengthened for all forms of motion and the range of motion for all forms of motion is improved.
There are many and diverse exercise devices known in the art, a number of which are specifically directed to wrist/forearm exercise, such as Canadian Patents Nos. 658,291 to Hotas and 1,134,404 to Brentham. However, despite their utility, such devices are generally directed to only a select type of wrist/forearm motion (e.g. only wrist flexion/extension), and accordingly provide limited benefits to the player who wishes to exercise the wrists and forearms through their entire range of motion for all primary types of wrist/forearm motion.
What is needed, therefore, is a device for exercising the forearm, wrist and hand, through their entire range of motion, for all primary types of wrist/forearm motion.
SUMMARY OF THE INVENTIONThe present invention accordingly seeks to provide a frictional exercise device that can be used by a player to strengthen muscles of the forearm, wrist and hand, providing resistance for all six primary types of motion discussed above.
According to one aspect of the present invention there is provided a device for exercising forearm, wrist and hand, the device comprising: a housing; a discoid member having a circumferential edge and opposed faces, the discoid member rotatably mounted on the housing; an anchor member on the housing adjacent the circumferential edge of the discoid member; biasing means connected to the housing adjacent the circumferential edge of the discoid member and spaced from the anchor member; an elongate friction member extending between the anchor member and the biasing means, the elongate friction member disposed against the circumferential edge of the discoid member, the elongate friction member having a first end attached to the anchor member and a second end attached to the biasing means; a shaft extending outwardly from at least one of the opposed faces; and handle means on the shaft for rotating the shaft to effect rotation of the discoid member; such that actuation of the handle means effecting rotation of the discoid member in a first direction results in a first normal friction between the elongate friction member and the circumferential edge, and actuation of the handle means effecting rotation of the discoid member in a second and opposite direction results in a second normal friction between the elongate friction member and the circumferential edge.
In exemplary embodiments of the present invention, the device further comprises adjusting means on the housing connecting the biasing means to the housing, the adjusting means connected to the biasing means for selectively adjusting biasing effected by the biasing means, thereby selectively adjusting normal friction between the elongate friction member and the circumferential edge. Most preferably, the biasing means comprise first and second extension springs, and the adjusting means comprise: a threaded adjustment bolt mated with the housing; a nut threaded onto the threaded adjustment bolt, such that rotating the threaded adjustment bolt causes the nut to move axially along the threaded adjustment bolt; projections extending outwardly from the nut; a bar for connecting to the second end of the elongate friction member; and the first and second extension springs connected at respective first ends to the projections and at respective second ends to the bar; such that rotating the threaded adjustment bolt in a first direction causes the nut to move away from the discoid member, increasing the normal friction between the elongate friction member and the circumferential edge.
The biasing means are preferably an extension spring, while the anchor member is preferably a post extending from the housing at least partially past the circumferential edge of the discoid member. The elongate friction member is preferably a band composed of material sufficient to effect a desired coefficient of friction between the elongate friction member and the circumferential edge of the discoid member, and the elongate friction member is preferably in direct contact with the circumferential edge along greater than half of the extent of the circumferential edge.
The shaft preferably extends generally perpendicularly from the at least one of the opposed faces, and most preferably from each of the opposed faces. The handle means may be disposed either generally parallel to the opposed faces of the discoid member and generally perpendicular to the shaft, or generally perpendicular to the opposed faces of the discoid member and generally parallel to the shaft; this would be dictated by the type of motion the player wished to address in the exercise period, as described in greater detail below.
The device is also preferably provided with vertical support means, which most preferably comprise a base member and a generally vertical mast extending upwardly therefrom, the generally vertical mast connected to the housing.
A device according to the present invention, therefore, can provide the player with a resistance exercise means, where the resistance to applied torque is different depending on which direction the player rotates the shaft. Depending on how the handle means are positioned, as described in greater detail below, the player can also use a device according to the present invention to exercise the hand/wrist/forearm through all six primary types of motion, through the entire range of motion. In addition to improving a players ability, such exercise can help to prevent sports-related injury.
A detailed description of an exemplary embodiment of the present invention is given in the following. It is to be understood, however, that the invention is not to be construed as limited to this embodiment.
BRIEF DESCRIPTION OF THE DRAWINGSIn the accompanying drawings, which illustrate an exemplary embodiment of the present invention:
Referring now in detail to the accompanying drawings, there is illustrated an exemplary embodiment of a device according to the present invention generally referred to by the numeral 10. Referring specifically to
Referring now in detail to
The device 10 further comprises adjusting means for adjusting the tension acting on the friction band 48.
The exemplary embodiment of the present invention also incorporates a support structure to assist in using the device 10. The support structure comprises a generally horizontal base 50, which serves as the support for a vertical mast 52. The mast 52 holds up the housing 12, and is connected to the housing 12 by means of a bracket 54. Preferably, the mast 52 is fully rotatable with respect to the base 50, which may take the form of a pin-and-socket arrangement (not shown).
The present invention seeks to provide frictional resistance as an aid to exercise. Friction is a resistive force that is a function of the force perpendicular to the contact surface (also called the “normal force”) and the coefficient of friction (which is a function of the materials brought into contact). In the exemplary embodiment of the present invention, friction is being generated between the circumferential edge 16 and the friction band 48 which is being forced against the circumferential edge 16.
As one end 56 of the friction band 48 is connected to a fixed anchor 24, rotation of the disc 14 in the first direction of rotation 38 will generate a first normal force. The other end 58 of the friction band 48 is connected to the extension springs 26, 62 (by means of the bar 66), so rotation of the disc 14 in the second direction of rotation 40 will generate a second normal force. As the anchor 24 is fixed, while the extension springs 26, 62 have an inherent flexibility, the first normal force will accordingly be greater than the second normal force, although using the threaded adjustment bolt 42 to increase the tension on the friction band 48 will narrow the difference between the first and second normal forces. The result is that a user may select either direction of rotation 38, 40 with the result that a different friction will be generated; if greater resistance is desired, for example, the user would select the first direction of rotation 38, but the second direction of rotation 40 would be selected if the user desired a lesser frictional resistance.
Referring now to FIGS. 3 to 5b, various orientations of the device 10 are illustrated, specifically various handle positions/orientations, each addressed to a different set of the primary types of wrist/forearm motion set out above.
In
Referring now to
Finally,
In addition, the exemplary embodiment allows for adjusting the resistance using the threaded adjustment bolt 42, so the various forms of exercise described above could be conducted at a variety of resistances as determined by the user to be desirable given the strength of the muscle group being worked. As the muscle group strength increased over time, the user could gradually adjust the resistance to enhance the benefits of the exercise.
While the exemplary embodiment illustrates different handles 34, 36 for use with the orientation set out in
While a particular embodiment of the present invention has been described in the foregoing, it is to be understood that other embodiments are possible within the scope of the invention and are intended to be included herein. It will be clear to any person skilled in the art that modifications of and adjustments to this invention, not shown, are possible without departing from the spirit of the invention as demonstrated through the exemplary embodiment. For example, various forms of support means could be employed with the present invention, including different mast 52 lengths for sitting or standing. Various friction band 48 and disc 14 materials could also be employed, as would be known to one skilled in the art, for generating different frictional resistances. Also, various means would be obvious for tensioning the friction band 48, for example using a compression spring for pressing the friction band 48 down onto the circumferential edge 16 (rather than extension springs 26, 62 for pulling the friction band 48 up against the circumferential edge 16), and various adjusting means would also be obvious to one skilled in the art. The invention is therefore to be considered limited solely by the scope of the appended claims.
Claims
1. A device for exercising forearm, wrist and hand, the device comprising:
- a housing;
- a discoid member having a circumferential edge and opposed faces, the discoid member rotatably mounted on the housing;
- an anchor member on the housing adjacent the circumferential edge of the discoid member;
- biasing means connected to the housing adjacent the circumferential edge of the discoid member and spaced from the anchor member,
- an elongate friction member extending between the anchor member and the biasing means, the elongate friction member disposed against the circumferential edge of the discoid member, the elongate friction member having a first end attached to the anchor member and a second end attached to the biasing means;
- a shaft extending outwardly from at least one of the opposed faces; and
- handle means on the shaft for rotating the shaft to effect rotation of the discoid member;
- such that actuation of the handle means effecting rotation of the discoid member in a first direction results in a first normal friction between the elongate friction member and the circumferential edge, and actuation of the handle means effecting rotation of the discoid member in a second and opposite direction results in a second normal friction between the elongate friction member and the circumferential edge.
2. The device of claim 1 further comprising adjusting means on the housing connecting the biasing means to the housing, the adjusting means connected to the biasing means for selectively adjusting biasing effected by the biasing means, thereby selectively adjusting normal friction between the elongate friction member and the circumferential edge.
3. The device of claim 2 wherein the biasing means comprise first and second extension springs, and the adjusting means comprise:
- a threaded adjustment bolt mated with the housing;
- a nut threaded onto the threaded adjustment bolt, such that rotating the threaded, adjustment bolt causes the nut to move axially along the threaded adjustment bolt;
- projections extending outwardly from the nut;
- a bar for connecting to the second end of the elongate friction member; and
- the first and second extension springs connected at respective first ends to the projections and at respective second ends to the bar,
- such that rotating the threaded adjustment bolt in a first direction causes the nut to move away from the discoid member, increasing the normal friction between the elongate friction member and the circumferential edge.
4. The device of claim 1 wherein the biasing means comprise an extension spring.
5. The device of claim 1 wherein the anchor member is a post extending from the housing at least partially past the circumferential edge of the discoid member.
6. The device of claim 1 wherein the elongate friction member is a band composed of material sufficient to effect a desired coefficient of friction between the elongate friction member and the circumferential edge of the discoid member.
7. The device of claim 1 wherein the elongate friction member is in direct contact with the circumferential edge along greater than half of the extent of the circumferential edge.
8. The device of claim 1 wherein the shaft extends generally perpendicularly from the at least one of the opposed faces.
9. The device of claim 1 wherein the shaft extends outwardly from each of the opposed faces.
10. The device of claim 1 wherein the handle means are disposed generally parallel to the opposed faces of the discoid member and generally perpendicular to the shaft.
11. The device of claim 1 wherein the handle means are disposed generally perpendicular to the opposed faces of the discoid member and generally parallel to the shaft.
12. The device of claim 1 further comprising vertical support means.
13. The device of claim 12 wherein the vertical support means comprise a base member and a generally vertical mast extending upwardly therefrom, the generally vertical mast connected to the housing.
Type: Application
Filed: Jul 6, 2005
Publication Date: Jan 11, 2007
Inventor: Byron Christensen (Calgary)
Application Number: 11/174,567
International Classification: A63B 21/012 (20060101);