Abstract:
An exercise device comprising a chair attachment assembly adapted for attachment to a chair at a location under a seat of the chair and configured to extend outwardly therefrom. A pair of leg supports are pivotally coupled at first ends thereof to a pivot point on the chair attachment assembly. Each leg support is independently moveable between a contracted position and an extended position. A leg holder is coupled to each leg support near a second end thereof. A resistance element is pivotally coupled between each leg support and the chair attachment assembly. Each resistance element is configured to provide resistance against both outward movement of the associated leg support from the contracted position to the extended position and inward movement of the associated leg support from the extended position to the contracted position.

Description:
REFERENCE TO RELATED APPLICATION 
   This application claims priority from U.S. Provisional Patent Application No. 60/886,626, filed 25 Jan. 2007 and entitled “LEG EXERCISER”. 

   TECHNICAL FIELD 
   This invention relates to exercise machines. Certain embodiments relate to leg exercise machines capable of being attached to or integrated with standard office chairs which can be used for exercising the legs while seated and without interfering with or impeding the performance of office duties. 
   BACKGROUND 
   Office work is routinely sedentary. Sedentary work brings with it an increased risk of poor health. Consequently, many office workers seek ways to integrate exercise into their workday. 
   There exist a number of prior art devices for exercising in chairs, including the following:
     U.S. Pat. No. 5,044,633 to Rice;   U.S. Pat. No. 5,599,260 to Rovinsky et al.;   U.S. Pat. No. 6,099,445 to Rovinsky et al.;   U.S. Patent Application Publication No. 2004/0053756 to Tremayne;   U.S. Patent Application Publication No. 2004/0142797 to Andre; and,   U.S. Pat. No. 6,979,284 to Curtis.   

   The inventor has identified a need for improved exercise devices which may be attached to or incorporated into chairs. 
   SUMMARY 
   The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements. 
   One aspect of the invention provides an exercise device comprising a chair attachment assembly adapted for attachment to a chair at a location under a seat of the chair and configured to extend outwardly therefrom. A pair of leg supports are pivotally coupled at first ends thereof to a pivot point on the chair attachment assembly. Each leg support is independently moveable between a contracted position and an extended position. A leg holder is coupled to each leg support near a second end thereof. A resistance element is pivotally coupled between each leg support and the chair attachment assembly. Each resistance element is configured to provide resistance against both outward movement of the associated leg support from the contracted position to the extended position and inward movement of the associated leg support from the extended position to the contracted position. 
   In one embodiment of the present invention, two adjustable resistance mechanisms, one for each leg, enable each leg to be exercised independently of the other. Additionally, so that the muscles on the top of the leg can be exercised independently from the muscles at the back of the leg, different resistance settings, requiring a different applied force, can be used for stretching the leg outward as opposed to retracting the leg to its original position. 
   In one embodiment the present invention comprises an exercise device which may be attached to a standard office chair (or built into an existing chair, sofa, bench, etc). The present invention has a chair attachment assembly with a pair of leg supports pivotally attached thereto. Each leg support is independently movable between an extended and a contracted position, and has a leg or ankle holder attached to its outer end. A resistance mechanism, which may comprise a hydraulic cylinder, is coupled to each leg support and resists motion of the associated leg support. The resistance mechanism optionally has an adjustment mechanism to regulate the amount of force required to move the attached leg support. In embodiments wherein the resistance mechanism is a hydraulic cylinder, the adjustment mechanism may comprise an adjustable valve, for example. 
   Further aspects of the invention and details of specific embodiments are set out below. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
     In drawings which illustrate non-limiting embodiments of the invention: 
       FIG. 1  is a schematic representation of a leg exerciser attached to an office chair according to one embodiment of the invention with both leg supports in a contracted position; 
       FIG. 2  shows the leg exerciser of  FIG. 1  with the right leg support in an extended position 
       FIG. 3  is a front view of the leg exerciser of  FIG. 1 ; 
       FIG. 4  is a top view of the leg exerciser of  FIG. 1 ; 
       FIG. 5  is a schematic representation of a leg exerciser attached to an office chair according to another embodiment of the invention; 
       FIG. 6  is a schematic representation of a leg exerciser attached to a chair according to another embodiment of the invention; and, 
       FIG. 7  shows the attachment assembly of the  FIG. 6  embodiment in isolation. 
   

   DESCRIPTION 
   Throughout the following description specific details are set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known elements may not have been shown or described in detail to avoid unnecessarily obscuring the disclosure. Accordingly, the description and drawings are to be regarded in an illustrative, rather than a restrictive, sense. 
   Referring to  FIGS. 1-4 , one embodiment of the present invention provides a leg exerciser  10  which may be attached to a chair  20  having a central post  22  such as, for example, an office chair. Leg exerciser  10  comprises a chair attachment assembly comprising a main supporting element  30  coupled to a bracket  100  at an inward end thereof. The terms “inward” and “outward” are used herein refer to the directions toward and away from central post  22  of chair  20 , respectively. In the illustrated embodiment, bracket  100  comprises a generally cylindrical bracket adapted for mounting leg exerciser  10  to a central post  22  of chair  20 , but it is to be understood that bracket  100  may be differently configured for mounting leg exerciser  10  to different types of chairs. 
   Bracket  100  is coupled to supporting element  30  by a tab  102  extending outwardly from bracket  100  in the illustrated embodiment. Tab  102  may have apertures therethrough for receiving bolts (not specifically enumerated), which also are received through slots  104  defined in supporting element  30 . Slots  104  allow a user to adjust the position of supporting element  30  inwardly and outwardly with respect to chair  20  by loosening the bolts, sliding supporting element to the desired position, and then tightening the bolts. In other embodiments, bracket  100  could be integrally formed with supporting element  30 , or could be coupled to supporting element  30  by other mechanisms. 
   A pair of leg supports  80 L and  80 R are pivotally attached to supporting element  30  at a pivot point  40  near an outward end of supporting element  30 . Left leg support  80 L is not visible in  FIG. 1 , since left leg support  80 L is hidden behind right leg support  80 R. Left leg support  80 L is visible in  FIG. 2 , which shows right leg support  80 R in an extended position. In the illustrated embodiment, leg supports  80 L and  80 R are coupled to supporting element  30  by means of a pin  42  (see  FIG. 3 ) inserted through apertures in leg supports  80 L and  80 R and supporting element  30 , and spacers  44  (see  FIG. 3 ) are provided to maintain a desired separation between leg supports  80 L and  80 R and supporting element  30 . 
   Pivot point  40  is preferably located at a height approximately equal to a height of the seat of chair  20 . In the illustrated embodiment, a user may adjust the position of supporting element  30  inwardly or outwardly, as discussed above, such that pivot point  40  is positioned approximately on a line passing through the user&#39;s knee joints. In embodiments wherein the position of supporting element  30  with respect to chair  20  is not adjustable, supporting element  30  may be provided with a plurality of apertures (not shown) in different locations for receiving pin  42  (see  FIG. 3 ), to allow the user to position pivot point  40  close to a line passing through the user&#39;s knee joints. 
   Each of leg supports  80 L and  80 R has a leg holder coupled thereto. In the illustrated embodiment, the leg holders comprise left and right leg grippers  90 L and  90 R which are respectively attached to leg supports  80 L and  80 R near the ends thereof opposite pivot point  40  (i.e., near the lower ends of leg supports  80 L and  80 R). Leg grippers  90 L and  90 R are shaped to receive a user&#39;s leg or ankle to facilitate pushing and pulling the leg supports  80 L and  80 R. As shown in  FIG. 4 , leg grippers  90 L and  90 R define leg receiving recesses  92 L and  92 R, respectively. Leg grippers  90 L and  90 R may be positioned such that the distance between leg receiving recesses  92 L and  92 R is suitable for receiving lower portions of a user&#39;s legs. Leg grippers  90 L and  90 R may be padded for the comfort of the user. Alternatively, the leg holders could comprise straps or the like for wrapping around the user&#39;s legs or ankles. 
   Footrests  95 L and  95 R may be respectively attached to the lower ends of leg supports  80 L and  80 R. In some embodiments, footrests  95 L and  95 R may be removable from leg supports  80 L and  80 R, or may be foldably coupled to leg supports  80 L and  80 R so that a user may fold footrests  95 L and  95 R up and out of the way when they are not desired. In some embodiments, footrests  95 L and  95 R may have a construction similar to footrests of a motorcycle. 
   Left and right resistance elements  60 L and  60 R are pivotally coupled between supporting element  30  and leg supports  80 L and  80 R, respectively. The inward ends of resistance elements  60 L and  60 R are pivotally attached to supporting element  30  at attachment points  70 L and  70 R, respectively. The outward ends of resistance elements  60 L and  60 R are pivotally attached to leg supports  80 L and  80 R at attachment points  50 L and  50 R, respectively. Attachment points  50 L and  50 R may be located between pivot point  40  and leg grippers  90 L and  90 L, respectively. In some embodiments, attachment points  50 L and  50 R may be located closer to pivot point  40  than to leg grippers  90 L and  90 L. 
   Resistance elements  60 L and  60 R provide resistance against both outward and inward movement of leg supports  80 L and  80 R. Resistance elements  60 L and  60 R may include adjustment mechanisms for individually varying the amount of force required to move leg supports  80 L and  80 R. The adjustment mechanisms may also permit different amounts of force to be required for outward movement of leg supports  80 L and  80 R than for inward movement of leg supports  80 L and  80 R. Resistance elements  60 L and  60 R may comprise, for example, hydraulic or pneumatic cylinders, and the adjustment mechanisms may comprise adjustable valves. 
   In operation, when a user is seated in chair  20 , the right leg is slipped into right leg gripper  90 R and the left leg in slipped into left leg gripper  90 L with both leg supports  80 L and  80 R in the contracted position shown in  FIG. 1 . To begin exercising, the user extends their right leg, for example. In so doing, the leg pushes against leg gripper  90 R and moves leg support  80 R in a direction rotationally away from the seated user to an extended position, as shown in  FIG. 2 . After the right leg is fully extended, the exerciser begins to push the left leg against gripper  90 L while contracting the right leg against gripper  90 R. This cycle may be repeated for as long as the exerciser desires. Alternatively, leg exerciser  10  could be used by extending and contracting both legs at the same time. 
     FIG. 5  shows a leg exerciser  10 ′ according to another embodiment of the invention. Leg exerciser  10 ′ is the same as leg exerciser  10  of  FIGS. 1-4 , except that leg exerciser  10 ′ comprises a calf exerciser mechanism  110  attached to right leg support  80 R. Another calf exerciser mechanism  110  may be attached to left leg support  80 L but has been omitted from  FIG. 5  to avoid cluttering the drawing. 
   Calf exerciser mechanism  110  comprises a resistance element  120  pivotally attached to right leg support  80 R at attachment point  130 . Resistance element  120  may comprise, for example, an adjustable hydraulic or pneumatic cylinder similar to resistance elements  60 L and  60 R. A foot gripper  140  is attached to the end of resistance element  120  opposite attachment point  130 . 
   In operation, a user seated in chair  20  places their foot in foot gripper  140 . The user may then exercise their calf muscles by raising and lowering their toes, such that their foot pulls and pushes on foot gripper  140 , which in turn contracts and extends resistance element  120 . 
     FIG. 6  shows a leg exerciser  150  according to another embodiment of the invention. Leg exerciser  150  is adapted for use with a chair  200  having a seat  210  coupled to a frame  220 . In the  FIG. 6  embodiment, the chair attachment assembly comprises an attachment plate  160  coupled to a supporting element  170 .  FIG. 7  shows attachment plate  160  and supporting element  170  in isolation. Attachment plate  160  is configured to be attached between seat  210  and frame  220  of chair  200 . The remaining components of leg exerciser  150  are equivalent to those of leg exerciser  10  described above with reference to  FIGS. 1-4  (and are identified with the same reference characters), and are not described again to avoid repetition. 
   While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope.