Abstract:
A suspension system for walk training in physical therapy is disclosed to include a framework formed of a top rail and two wheeled posts supporting the top rail, a suspension mechanism, which has a suspension rod suspending from the top rail by a suspension rope for securing a harness for a patient, a spring force control unit fixedly mounted in the framework for stretching the suspension rope and adjusting the stretch force to the suspension rope, an elevation adjustment unit fixedly mounted in the framework for adjusting the elevation of the suspension rod, and a suspension force measurement unit for measuring the pull force of the suspension rope.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to apparatus for physical therapy and more particularly, to a suspension system for walk training, which is conveniently adjustable to fit different users and different walk training requirements. 
   2. Description of the Related Art 
   Various gait training devices are known for physical therapy. Further, a suspension system may be used with a gait training device to help the patient when taking a walk training therapy. A conventional suspension system for this purpose simply uses a suspension mechanism to help the patient stand on the floor. This suspension mechanism is not vertically stretchable to match with the patient&#39;s walking motion. 
   In recent years, suspension systems having a vertically stretchable function have been developed to help patients in walk training. These suspension systems commonly use an elastic rope and a tensile spring to suspend a suspension rod. When in use, the patient is fastened with a harness and then the harness is hung on the suspension rod. However, these improved designs of suspension systems are still not satisfactory in function because they are not adjustable to fit different patients having different body heights or to fit different suspension requirements. Further, these suspension systems are commonly complicated and expensive, not economic to hospitals and patients. 
   SUMMARY OF THE INVENTION 
   The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide a suspension system for walk training, which can conveniently be adjusted to change the elevation of the suspension rod to fit different users. It is another object of the present invention to provide a suspension system for walk training, which can conveniently be controlled to adjust the suspension force to fit different training requirements. 
   To achieve these and other objects of the present invention, the suspension system comprises a framework, the framework comprising two posts vertically arranged in parallel, a top rail horizontally connected between the posts, and two wheel assemblies respectively provided at the posts at a bottom side for moving the framework on a flat surface; a suspension mechanism, the suspension mechanism comprising a suspension rod suspending below the top rail, and a suspension rope mounted in the framework to suspend the suspension rod from the top rail; a spring force control unit fixedly mounted in the framework and connected with one end of the suspension rope for stretching the suspension rope and adjusting the stretch force to the suspension rope; an elevation adjustment unit fixedly mounted in the framework and adapted to move the suspension rope and to further adjust the suspension elevation of the suspension rod; and a suspension force measurement unit, the suspension force measurement unit comprising a pull force sensor connected in series to the suspension rope for measuring the pull force applied to the suspension mechanism. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an elevational view of a suspension system according to the present invention. 
       FIG. 2A  is an exploded view in an enlarged scale of a part of the suspension system according to the present invention, showing the structure of the spring force control unit. 
       FIG. 2B  is an assembly view of  FIG. 2A . 
       FIG. 3A  is an exploded view in an enlarged scale of a part of the suspension system according to the present invention, showing the structure of the elevation adjustment unit. 
       FIG. 3B  is an assembly view of  FIG. 3A . 
       FIG. 4A  is an exploded view in an enlarged scale of a part of the suspension system according to the present invention, showing the structure of the suspension force measurement unit. 
       FIG. 4B  is an assembly view of  FIG. 4A . 
       FIG. 5  is a cutaway view of the suspension system according to the present invention. 
       FIG. 6  is a schematic drawing showing one application example of the present invention. 
       FIG. 7  is a schematic drawing showing another application example of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to  FIGS. 1˜5 , a suspension system for walk training in accordance with the present invention is shown comprised of a framework  10 , a suspension mechanism  20 , a spring force control unit  30 , an elevation adjustment unit  40 , and a suspension force measurement unit  50 . 
   The framework  10  comprises a top rail  11 , two posts  12  respectively connected to the two distal ends of the top rail  11  to hold the top rail  11  in horizontal, two wheel assemblies  121  respectively fastened to the posts  12  at the bottom side for allowing movement of the framework  10  on the floor conveniently, and two handrails  122  respectively adjustably provided at the posts  12  at a suitable elevation. According to this embodiment, the top rail  11  and the posts  12  are respectively formed of hollow frame bars. 
   Referring to  FIG. 1  again, the suspension mechanism  20  comprises a suspension rod  21 , two hanging hooks  211  respectively provided at the two distal ends of the suspension rod  21  for securing a harness (not shown) to be fastened to the patient who is going to take the walk-training exercise, and a suspension rope  22 , which is inserted through the top rail  11  and has a first end extended out of a bottom center hole (not shown) of the top rail  11  and fixedly fastened to the midpoint of the suspension rod  20  and a second end extending through the elevation adjustment unit  40  in one of the two posts  12  and then extending through the top rail  11  into the inside of the other one of the two posts  12  and coupled to the spring force adjustment unit  30  (further, pulleys are used to guide movement of the suspension rope  22 ). 
   Referring to  FIGS. 1 ,  2 A,  2 B and  5  again, the spring force control unit  30  comprises a holder frame  31  fixedly mounted inside one post  12 , a winch  32  pivotally supported on the inside of the holder frame  31 , a torsional spring  33 , which is supported on (a shaft at) one side of the winch  32  and has a first end fixedly connected to one side of the winch  32  and a second end, a worm gear  34  pivotally mounted inside the holder frame  31  and fixedly connected to the second end of the torsional spring  33 , a crank handle  35  pivotally mounted in the respective post  12 , and a worm  351  fixedly provided at one end of the crank handle  35  and meshed with the worm gear  34 . The second end of the aforesaid suspension rope  22  is connected to the winch  32 . The torsional spring  33  imparts a biasing force to the winch  32 , causing the winch  32  to roll up the suspension rope  22 . 
   Referring to  FIGS. 1 ,  3 A,  3 B and  5  again, the elevation adjustment unit  40  comprises a holder frame  41  fixedly mounted inside the other post  12 , a vertical screw rod  42  pivotally mounted on the holder frame  41  at the top, a nut  43  threaded onto the vertical screw rod  42  above the holder frame  41 , a pulley  44  fixedly fastened to the nut  43 , a crank handle  45  pivoted to the respective post  12 , and a bevel gear transmission mechanism  421  coupled between the crank handle  45  and the bottom end of the vertical screw rod  42 . Rotating the crank handle  45  clockwise/counter-clockwise will rotate the vertical screw rod  42 , thereby causing the pulley  44  to be moved with the nut  43  upwards/downwards along the vertical screw rod  42 . Further, the aforesaid suspension rope  22  extends over the pulley  44  and connected between the suspension rod  21  and the winch  32 . Therefore, rotating the crank handle  45  can adjust the elevation of the suspension rod  21 . 
   Referring to  FIGS. 4A ,  4 B and  5  again, the suspension force measurement unit  50  comprises a pull force sensor  51 , which is mounted inside the top rail  11  and has two ends connected in series to the suspension rope  22  for measuring the suspension force of the suspension mechanism  20 , a track  53  fixedly mounted inside the top rail  11  and extending along the length of the top rail  11 , a slide  52  fixedly provided at the bottom side of the pull force sensor  51  and coupled to and movable along the track  53 , two stop blocks  531  respectively provided at the track  53  near the two ends of the track  53  to limit the moving distance of the slide  52  on the track  53 , and two buffer springs  532  respectively provided at the stop blocks  531  and facing the slide  52  for buffering the striking force of the slide  52 . 
   The use of the present invention will be outlined hereinafter with reference to  FIGS. 6 and 7  and  FIG. 1  again. After the harness has been fastened to the patient&#39;s body, the hanging hooks  211  of the suspension mechanism  20  are fastened to the harness by means of the help of the therapist or another person. At this time, the patient can stand up and hold the handrails  122  with the hands, and then start to walk (see  FIG. 6 ) or to run on a treadmill (see  FIG. 7 ). 
   Referring to  FIGS. 2A and 2B  again, because the suspension rope  22  has one end coupled to the winch  32  and the torsional spring  33  imparts a biasing force to the winch  32  to roll up the suspension rope  22 , the suspension rod  21  is smoothly moved up and down following the movement of the patient. 
   Further, the therapist can operate the crank handle  35  to rotate the worm gear  34 , so as to further adjust the spring force of the torsional spring  33  subject to different operation requirements. Further, the engagement between the worm gear  34  and the worm  351  is automatically locked, preventing reverse rotation of the winch  32 . Lock means to automatically lock the engagement between the worm gear  34  and the worm  351  can easily be achieved by means of conventional techniques. Therefore, the therapist can easily adjust the suspension force of the suspension mechanism  20 , controlling the vertical moving range of the suspension rod  21  to fit different walk training requirements for different patients. 
   Referring to  FIGS. 3A ,  3 B and  5  again, the therapist can operate the crank handle  45  of the elevation adjustment unit  40  to pull or release the suspension rope  22  and to further adjust the elevation of the nut  43  and the pulley  44 , so as to further adjust the elevation of the suspension rod  21  of the suspension unit  20 . When lowering the elevation of the pulley  44 , the suspension rod  21  is relatively lifted. On the contrary, when lifting the pulley  44 , the suspension rod  21  is relatively lowered. 
   Referring to  FIGS. 4A and 4B  again, the pull force sensor  51  of the suspension force measurement unit  50  is connected in series to the suspension rope  22  of the suspension mechanism  20 . During operation of the suspension system, the indicator or display means (not shown) that is electrically connected to the pull force sensor  51  automatically indicates the suspension force of the suspension mechanism  20 . Further, the stop blocks  531  and the buffer springs  532  limit the moving distance of the slide  52  on the track  53 , preventing falling of the patient during walk training. 
   A prototype of suspension system has been constructed with the features of  FIGS. 1˜7 . The suspension system functions smoothly to provide all of the features discussed earlier. 
   Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.