BACKGROUND OF THE INVENTION 
     The invention relates to an exercise device for developing muscles in the hand, arm, and chest by adduction or abduction of one or both hands. 
     Good hand strength is important in many daily, athletic, and therapeutic activities, and is directly related to the strength of the wrists, arms, and upper body. To develop hand strength, previously known hand exercisers, such as rubber or foam balls which the user holds in his palm and squeezes, allow the user to contract and then stretch his finger and hand muscles, i.e., to exercise abductor and adductor muscles. Many of such devices are referred to herein as active exercise devices. That is, the device exerts a force of its own which causes it to return to its original state. As referred to herein then, a &#34;non-active&#34; other hand, does not exert a force to cause the device to return to its original position. Rather, the user must exert force by abduction and adduction to move the device to different positions. 
     Other known active exercisers include two handles connected by a spring or other compressive force which urges the handles either away from one another for adduction, i.e, wherein a user grasps the handles from the outside and attempts to force the handles together, or toward one another for abduction, i.e., wherein a user places his thumb and fingers on the inside of either handle and attempts to force the handles apart. Another active exerciser includes two parallel rods connected to a rectangular frame, the size of which can be adjusted by placing a pin through corresponding holes in members of the frame. The rods are biased towards one another by elastic bands which provide a resistant force when the user attempts to pull the rods away from one another. 
     SUMMARY OF THE INVENTION 
     In general, the invention features hand exercise device having a first handle and a second handle, opposed to one another and positioned in a manner to be engaged simultaneously by a hand to be exercised, which compresses and expands the handles against the force of a means for resistance of movement of the first handle relative to the second. 
     In preferred embodiments, the hand exercise device includes a second pair of handles opposed to each other and positioned in a manner to be engaged by a second hand. The means for resistance is a frictional engagement of a frictional element and the handles, the force of the engagement being adjustable by means of a threaded element, e.g., a wing nut and bolt arrangement. Resistance of movement between the frictional element and the handles can be accomplished by the alternating application of force to the pairs of handles, which are disposed in a fixed angular relationship to one another. The angular relationship of the opposing handles is achieved by cooperative engagements, e.g., grooves in the handles which can be released and repositioned at different angles. The opposed handles can also include a padded sleeve with apertures for a user&#39;s fingers and thumb, or a strap for receiving a portion of a hand between the strap and the handle to aid the user in separating the handles after they have been forced together. 
     Other features and advantages will become clear from the drawings and the following discussion of a presently preferred embodiment. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring first briefly to the drawings: 
     FIG. 1 is a perspective view of a hand exerciser according to the present invention, suitable for use with one or two hands; 
     FIG. 2 is a plan view of the inner face of a handle of the hand exerciser shown in FIG. 1; 
     FIG. 3 is a plan view of the side of the handle shown in FIG. 2; 
     FIG. 4 is an exploded side view of the hand exerciser shown in FIGS. 1-3; 
     FIG. 5 is a perspective view of the hand exerciser shown in FIG. 1, including padded sleeves; 
     FIG. 6 is a perspective view of another hand exerciser according to the invention, suitable for use with one hand; and 
     FIG. 7 is a perspective view of the hand exerciser shown in FIG. 6, including sleeves with straps. 
    
    
     Referring to FIG. 1, a hand exerciser 10 has four handles 12a-12d, preferably formed of a strong hard plastic or stainless steel. The handles 12 each include a cylindrical upper portion 16 having a length L and a diamter D 1 , e.g., 4 inches long and 1/2-3/4 inches in diameter, and an integral body portion 18 having a diameter D 2  and a thickness T, e.g., 2 inches in diameter and 1/4 inch thick. In addition, a shoulder portion 20 at the connection of the body 16 and the disk 18 provides strength to the handles 12, thereby ensuring that the handles do not break off from the disks. 
     Referring to FIGS. 2, 3, and 4, one face of each of the body portions 18 defines a number of radially extending grooves 22 which correspond and interlock with like grooves on the face of another of the disks 18. Thus, the body portion 18 of a first upper handle 12a interlocks with the body portion 18 of second upper handle 12d, and the body portion 18 of a first lower handle 12c interlocks with the body portion 18 of a second lower handle 12b. The interlocked handles 12 are then separated by a friction disk 24, and held together in their locked positions by a bolt 26, which passes through the centers of the disks 18 and the friction disk 24. A washer 28 and wing nut 30, secure the bolt and define the amount of resistance created by the friction disk. 
     In an important aspect of the invention, the angle between the handles 12 is defined by the position at which the body portions 18 on each are interlocked. The angle is, therefore, adjustable to different hand sizes by loosening the wing nut 30, separating the body portions 18, rotating the body portions to another angle, interlocking the grooves 22, and tightening the wing nut. Such a feature is usually found lacking in previously known exercisers in which the handles are held together or apart at a distance defined by a spring or other compressive force. Furthermore, in the present invention, it is possible to adjust the angle of one pair of the handles 12 differently than the angle of the other pair of the handles 12 to accommodate a user having a smaller grip or lesser strength in one hand. This feature, likewise, is lacking in previously known exercisers. 
     In use, the exerciser 10 is held in two hands by the handles 12. The handles 12 are then forced together and apart by alternately contracting one hand and then the other. The amount of resistance is varied by loosening or tightening the wing nut 30, or by contracting one hand to force an expanded pair of handles 12 together while attempting to hold the other pair of handles in an already contracted position. Other variations are, of course, possible. For example, the user can hold the device in an overhand or underhand grip, or a combination of the two. 
     Referring to FIG. 5, the exerciser 10 may be further fitted with resilient padded sleeve 32 and 34 which slide over the body portions 16 of the handles 12. To accommodate a user&#39;s hand, sleeve 32 defines a thumb hole 36, while sleeve 34 defines four finger holes 38. Thus, a user places his thumb and fingers in the holes 36 and 38 and is able to practice both abduction and adduction exercises by forcing one pair of the handles 12 together with one hand, while at the same time forcing the other pair of the handles apart with the other hand. With the addition of the sleeves 32 and 24, it is further possible to use the exerciser 10 for abduction and adduction exercises with just one hand, i.e., by alternately forcing one pair of handles together and apart. 
     Referring to FIG. 6, an alternative embodiment of the present invention provides a hand exerciser 40, suitable for use with one hand only. The exerciser 40 includes a pair of handles 42 each having a cylindrical handle portion 46 and a body portion 48 connected by a shoulder portion 50. The opposing faces of the body portions 48 are smooth, i.e., not grooved as are the opposing faces of body portions 18 of the embodiment of FIGS. 1-5, but are nonetheless separated by a friction disk 54 (shown in dotted lines) and held together by a bolt 56, which passes through the centers of the body portions 48 and the friction disk 54. A washer 58 and wing nut 60 secure the bolt and define the amount of resistance created by the friction disk 54. 
     The exerciser 40 further includes padded sleeves 62 and 64 which slide over the handle portions 46 of the handles 42. Sleeve 62 defines a thumb hole 66, while sleeve 64 defines four finger holes 68. Thus, a user places his thumb and fingers in the holes and can practice abduction an adduction exercises by forcing the handles 42 together, against the resistive force of the friction disk 54, and forcing the handles apart, also against the resistive force of the friction disk. 
     Advantages of both embodiments of the above described exercisers with their sleeve elements include allowing the user to practice both abduction and adduction with the same hand exerciser, and to vary the degree of resistance by tightening or loosening the wing nut 60. Furthermore, because the hand exerciser is a device, the user controls the final stopping position of the handles. Thus, there is no danger of the handles snappingg together or apart against the will and strength of the user. By contrast, previously known active exercisers, especially those in which the handles are connected by springs, have a single resistance setting which is typically greater than the user&#39;s strength. Thus, it is possible for the handles to snap back to their original position despite the user&#39;s efforts, thereby discouraging the user from continuing the exercise, or even injuring the user. 
     It will be appreciated that other variations on the above described exerciser are possible. For example, padded sleeves without finger holes can be fitted over the handles of the two handed exerciser 40 to increase the size of the handles for users whose hands are unable to grip small diameter objects. Also, since the holes on the padded sleeves described in connection with exercisers 10 and 40 are not adjustable in their size or spacing, padded sleeves without finger holes can be used. Referring to FIG. 7, such sleeves 70 include a strap 72 attached to either end of the sleeve, e.g., by velcro attachments or a snap, through which the user&#39;s hand fits and can be used to allow the user to practice abduction and adduction exercises regardless of the size or spacing of his fingers. Additional embodiments are within the following claims.
A passive hand exercise device having first and second handles. The handles are opposed to one another and positioned to be engaged simultaneously by a hand to be exercised, which compresses and expands the handles against a passive resistance force applied against movement of the first handle relative to the second.