Patent Publication Number: US-6991609-B2

Title: Massage assembly and massage machine incorporating same

Description:
FIELD OF THE INVENTION 
   The present invention relates to a massage assembly for massaging the shoulders, back and/or waist of the user, and more particularly to a massage assembly for converting a reciprocating movement of a massage unit to the movement of therapeutic members, and to a massage machine having the assembly incorporated therein. 
   BACKGROUND OF THE INVENTION 
   Massage machines are available which have therapeutic members movable upward and downward, leftward and rightward and/or forward and backward for massaging the shoulders, back and waist of the user. Such a massage machine includes a massage assembly comprising a massage unit provided with therapeutic members and reciprocatingly movable. The massage assembly is incorporated in the backrest of a chair or a bed. 
   The massage assembly is equipped with a power source for reciprocatingly moving the massage unit and another power source for moving the therapeutic members. The massage machine therefore has the problem of being large-sized and heavy-weighted. 
   Further massage machines are available wherein a motor for moving the therapeutic members is mounted on the massage unit. In the case where massage machines of the chair type have this construction, the center of gravity of the machine shifts upward when the massage unit, which is given an increased weight by the motor mounted thereon, moves upward. This entails the problem of impairing the stability of the chair. 
   An object of the present invention is to provide a massage assembly wherein the reciprocating movement of a massage unit is converted to the movement of therapeutic members and which is provided with a single motor for moving the massage unit and the therapeutic members and is thereby made lightweight, compacted and simplified in construction, and a massage machine having the massage assembly incorporated therein. 
   SUMMARY OF THE INVENTION 
   To fulfill the above object, the present invention provides a massage assembly wherein a massage unit comprising a therapeutic member for massaging the body of the user by a massaging action capable of producing a kneading and/or a tapping movement wherein the therapeutic member is reciprocatingly moved between a pair of frames and which comprises a motion converting mechanism for converting a reciprocating movement of the massage unit to a kneading and/or tapping movement of the therapeutic member. As used herein the term, “massaging action”, shall mean such action as will selectively produce a kneading movement, a tapping movement, or a combination of such movements. 
   The present invention also provides a massage machine comprising the massage assembly as incorporated in a backrest of a chair or bed. 
   The massage assembly of the invention moves the therapeutic member by converting the reciprocating movement of the massage unit to this movement. Accordingly, a single motor for reciprocatingly moving the massage unit serves as the sole drive source. The massage unit need not be provided with another motor for moving the therapeutic member, nor is it necessary to provide, for example, electric wiring for this motor. This renders the massage unit and the massage assembly compact and lightweight, further resulting in decreased operation noise and reduced power consumption. 
   Since the massage assembly can be compacted and made lightweight, the backrest of the chair or bed of the massage machine can be reduced in thickness to render the massage machine also lightweight. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a massage machine of the chair type; 
       FIG. 2  is a rear view partly in section and showing a massage assembly of the invention; 
       FIG. 3  is a view in section along a therapeutic shaft of the massage assembly of the invention; and 
       FIG. 4  is a view in section along a screw rod of the massage assembly of the invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   The present invention will be described below with reference to a massage machine of the chair type to which the invention is applied. The invention is applicable not only to the chair type but also to massage machines of the bed type. In the following description, the term “upper” refers to the direction toward which the shoulders are positioned when the user is seated in the chair, and the term “lower” to the direction toward which the waist of the seated user is positioned. 
     FIG. 1  is a perspective view of a massage machine  10  of the chair type. A chair  12  comprises a seat  14  for the user to sit in, and a backrest  16  extending upward from the rear end of the seat  14 . The backrest  16  may be made tiltable relative to the seat  14 . 
   The backrest  16  is enclosed with a fabric or like cover  18 . The cover  18  has disposed therein a massage assembly  20  of the invention. 
   As shown in  FIG. 2 , the massage assembly  20  comprises upper and lower frames  22 ,  23 , and guide rails  24 ,  24  interconnecting these frames. The frames  22 ,  23  and/or guide rails  24 ,  24  are attached, for example, to the frame of the backrest  16 . 
   The guide rails  24 ,  24  comprise channel-shaped rail portions  25 ,  25 , which are attached to the frames  22 ,  23 , with their recesses facing inward toward each other as shown in  FIG. 3 . 
   Each rail portion  25  is provided on the inner side thereof with a rack  26 , which is preferably made of a resin so as to ensure reduced operation noise. 
   Disposed between the guide rails  24 ,  24  is a screw rod  30  extending through and supported by the upper and lower frames  22 ,  23 . The screw rod  30  has a pulley  31  mounted on its lower end and connected by a belt  34  to a motor  33  fixed to the lower frame  23  for power transmission. The motor  33  is mounted on the lower frame  23  to thereby lower the center of gravity of the assembly  20  and give good stability to the chair  12 . 
   When driven, the motor  33  rotates the screw rod  30  positively or reversely. The expression “positive rotation” means the rotation in such a direction as to move a massage unit  40  to be described below upward, and the expression “reverse rotation” means the rotation in such a direction as to move the massage unit  40  downward. 
   With reference to  FIGS. 2 to 4 , the massage unit  40  is reciprocatingly movably disposed between the upper and lower frames  22 ,  23 . The massage unit  40  comprises therapeutic members  50 ,  50  arranged on a base plate  41 . The base plate  41  is a box having an open front side and centrally provided with threaded sleeves  42 ,  42  screwed on the screw rod  30 . The base plate  41  is provided with a therapeutic shaft  52  orthogonal to the screw rod  30 . The therapeutic members  50 ,  50  at left and right are mounted on the therapeutic shaft  52  and spaced apart from each other by a predetermined distance. The therapeutic shaft  52  is rotatably supported by a shaft bearing plate  59  supported by upper and lower portions of the base plate  41  and positioned centrally of the front opening thereof. The shaft  52  carries at opposite ends thereof rollers  53  fitting in the respective rail portions  25  of the guide rails  24 . The rollers  53  are preferably made of a resin. 
   Pinions  54  meshing with the respective racks  26  are fixed to the therapeutic shaft  52  rotatably therewith and positioned closer to the center of the assembly  20  than the rollers  53  to provide a motion converting mechanism. Preferably, the pinions  54  are made of a resin to ensure reduced operation noise. 
   Preferably, the rollers  53  and the pinions  54  are so adapted that even when the massage unit  40  is pushed rearward by the user, the force acts on the rollers  53 , with a clearance maintained between each pinion  54  and the rack  26 . This reduces the friction to be produced between the rack  26  and the pinion  54  to diminish the wear on these members and reduce the operation noise. 
   When the screw rod  30  is rotated positively or reversely, the threaded sleeves  42  are moved upward or downward by screw thrust to reciprocatingly move the base plate  41  coupled to the threaded sleeves  42 . Since the therapeutic shaft  52  has its opposite ends held in meshing engagement with the racks  26  by the respective pinions  54 , the shaft  52  rotates when the pinions  54  travel on the racks  26  while in rotation with the reciprocating movement of the base plate  41 . 
   The therapeutic shaft  52  has the therapeutic members  50 ,  50  mounted thereon as seen in  FIGS. 2 to 4 . The therapeutic members  50 ,  50  each comprise an arm  56  extending upward or downward as bent at an obtuse angle at its midportion, and kneading balls  55 ,  55   a  rotatably mounted on respective opposite ends of the arm  56  as shown in  FIG. 4 . By an attaching member  61  fixedly fitted around the shaft  52 , a support bearing  60  is mounted on the bent portion of the arm  56 , with the center of rotation of the bearing  60  inclined with respect to the shaft  52  and positioned eccentrically thereof. Each of the members  50 ,  50  is supported by the bearing  60  on the shaft  52 , as inclined with respect to the shaft. 
   As shown in  FIGS. 3 and 4 , each member  50  has a contact piece  57  projecting rearward from the rear end thereof. The rear wall of the base plate  41  has upper and lower stoppers  43 ,  43   a  projecting therefrom toward a path of movement of the contact piece  57  for limiting the angle of pivotal movement of the therapeutic member  50 . 
   The arm  56  is provided below the bent portion thereof with means  58  for biasing the arm  56  rearward. The illustrated biasing means  58  is a coil spring and extends between, and is attached to, the arm  56  and the base plate  41  for biasing the lower portion of the arm  56  rearward so that the upper kneading ball  55  will project forward. 
   When free of load, each therapeutic member  50  is in a standby state, with its contact piece  57  held in bearing contact with the upper stopper  43  by the biasing means  58  and with the upper kneading ball  55  projecting forward. 
   When the therapeutic shaft  52  is rotated, the therapeutic members  50 ,  50  act to rotate with the shaft  52  following the rotation thereof, whereas because each member  50  has its lower portion biased rearward by the biasing means  58  and because the angle of pivotal movement of the member is limited by the stoppers  43 ,  43   a , the member  50  moves up and down within the range limited by the contact of the piece  57  with the stoppers  43 ,  43   a  while pivotally moving leftward and rightward without following the shaft  52 . 
   The massage assembly  20  is disposed within the backrest  16  of the chair  12  shown in  FIG. 1 , with the screw rod  30  positioned in parallel to the longitudinal direction of the backrest  16 , and the cover  18  is provided over the backrest. 
   The operation of the massage machine  10  thus constructed will be described. 
   When the motor  33  is driven with the user seated in the chair  12 , the screw rod  30  rotates. The threaded sleeves  42  of the massage unit  40  are in screw-thread engagement with the screw rod  30 , so that when the screw rod  30  rotates positively, the massage unit  40  is moved upward by the resulting screw thrust. When the screw rod  30  is rotated reversely, the unit  40  is moved down. 
   The reciprocating movement of the massage unit  40  causes the pinions  54 ,  54  on the therapeutic shaft  52  to travel on the racks  26 ,  26  while in rotation. The rotation of the pinions  54 ,  54  rotates the shaft  52 . 
   The rotation of the therapeutic shaft  52  moves the therapeutic members  50 ,  50  while pivotally moving the members leftward and rightward, whereby the user can be massaged by kneading in combination with a rolling massage afforded by the reciprocating movement of the massage unit  40 . 
   With the massage assembly  20  of the invention and the massage machine  10  incorporating the assembly, the reciprocating movement of the massage unit  40  can be converted to the reciprocating movement of the therapeutic members  50 ,  50 . This eliminates the need to provide another drive source for moving the members  50 ,  50 . 
   Further with the massage assembly  20  of the foregoing construction, the massage unit  40  or the kneading balls  55 ,  55   a  are likely to be forcibly pushed rearward by the user during massaging, whereas the force acts on the rollers  53  bearing on the guide rails  24 , with a predetermined clearance maintained between each pinion  54  and the rack  26 . Even if the pinion  54  and the rack  26  are made of a resin, a great frictional force will not be produced therebetween, with wear on the teeth and occurrence of noise precluded. 
   Although the screw rod  30  is used for reciprocatingly moving the massage unit  40 , the screw rod  30  can be replaced by a chain reeved around the upper and lower frames  22 ,  23  and movable by the rotation of a motor, with a massage unit attached to the chain, so that the massage unit  40  is reciprocatingly movable by the travel of the chain. 
   The foregoing embodiment is adapted to perform a kneading massage as described above, whereas the massage assembly can be adapted to perform a tapping massage or the combination of a kneading massage and a tapping massage by reciprocatingly moving the therapeutic members  50 ,  50  upward and downward. 
   Apparently, the present invention can be modified or altered by one skilled in the art without departing from the spirit of the invention. Such modifications are included within the scope of the invention as set forth in the appended claims.