Abstract:
The invention provides a massage machine wherein massage arms provided with kneading balls are held inclined forward to give a suitable massage. The massage machine comprises a kneading shaft ( 40 ) disposed on the massage unit ( 20 ) substantially horizontally, pivotal levers ( 33 ),( 33 ) supported by the kneading shaft ( 40 ), massage arms ( 32 ),( 32 ) supported by forward ends of the respective pivotal lever and kneading balls ( 31 ),( 31 ) provided on the respective massage arms each at a position obliquely above the position where the massage arm is supported by the pivotal lever. An arm lock mechanism ( 80 ) is coupled to the massage unit for holding the kneading balls pushed out forward, and the arm lock mechanism tiltably supports arm lock rods ( 83 ),( 83 ) each having one end connected to the massage arm at a position away from the position where the massage arm is supported by the pivotal lever. Each of the arm lock rods is forwardly tiltable by the arm lock mechanism to hold the massage arm with the kneading ball pushed out forward.

Description:
FIELD OF THE INVENTION 
   The present invention relates to massage machines of the chair type comprising kneading balls which can be held pushed out forward for massaging the person to be treated. 
   BACKGROUND OF THE INVENTION 
   Massage machines of the chair type are available which have a chair for a person to sit in to have his or her neck, shoulders, back or waist massaged. 
   The chair-type massage machine comprises a massage unit provided inside the backrest of the chair and movable upward and downward. The massage unit has a pair of opposite therapeutic fingers each comprising a massage arm bent at an obtuse angle and carrying a pair of kneading balls respectively at opposite ends thereof, and a pivotal arm for three-dimensionally moving the massage arm leftward, rightward, upward, downward, forward and rearward. 
   The massage arm is supported by the pivotal arm and biased by a spring so as not to freely rotate relative to the pivotal arm and to position the upper kneading ball as projected forward slightly beyond the lower kneading ball [see, for example, the publication of JP-A No. 2002-143253 (page 4, FIGS. 1 to 3)]. 
   The chair-type massage machine has its backrest covered with a fabric cover or the like. It is likely that the fabric cover will be tensioned by the user leaning against the backrest. If the fabric cover is tensely stretched when a massage is to be given to the person, the massage arm is forced by the cover to stretch the spring when to be tilted, with the result that the massage arm is unable to incline, failing to deliver a sufficient therapeutic force to the person to be massaged. 
   Difficulties are encountered especially in giving a kneading or tapping massage to the shoulder unless the upper kneading ball is pushed out forward when massaging the upper portion of the shoulder of the person to be treated. 
   An object of the present invention is to provide a massage machine of the chair type wherein massage arms provided with kneading balls can be held inclined forward so as to give a suitable massage. 
   SUMMARY OF THE INVENTION 
   To overcome the above problem, the present invention provides a massage machine of the chair type comprising:
         a backrest provided on a chair for the person to be massaged to sit in,   a massage unit reciprocatingly movable upward and downward longitudinally of the backrest,   a kneading shaft disposed on the massage unit substantially horizontally and rotatable by a kneading motor,   pivotal levers supported as inclined on the kneading shaft,   massage arms supported by forward ends of the respective pivotal levers, and   kneading balls provided on the respective massage arms each at a position obliquely above the position where the massage arm is supported by the pivotal lever,   an arm lock mechanism being coupled to the massage unit for holding the kneading balls pushed out forward,   the arm lock mechanism tiltably supporting arm lock rods each having one end connected to the massage arm at a position away from the position where the massage arm is supported by the pivotal lever,   each of the arm lock rods being forwardly tiltable by the arm lock mechanism to hold the massage arm with the kneading ball pushed out forward.       

   With the chair-type massage machine of the present invention, the kneading balls can be held forwardly pushed out by the arm lock mechanism regardless of the intensity of tension of the fabric cover of the backrest. The kneading balls therefore reach the upper portions of the shoulders of the person to be treated to give a highly effective massage. 
   A finger-pressure massage can be given by pushing out the kneading balls forward by the arm lock mechanism, with the therapeutic fingers in contact with the back, waist or the like. 
   In order to give a kneading or tapping massage in the usual manner, the kneading balls can be retracted so as not to be forced against the person to be treated. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a sectional view of a backrest of a massage machine of the chair type; 
       FIG. 2  is a sectional view of the backrest with a massage unit and therapeutic fingers pushed out forward; 
       FIG. 3  is a rear view of the massage unit; 
       FIG. 4  is a perspective view of the massage unit as it is seen obliquely from behind on the right side thereof; 
       FIG. 5  is a perspective view showing the main components of the massage unit as separated from the machine; 
       FIG. 6  is a perspective view of the massage unit as it is seen obliquely from behind on the left side thereof; and 
       FIG. 7  is a sectional view showing the main components of the massage unit as separated from the machine. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The massage machine of the chair type of the invention has a backrest  12  connected as by a frame to the rear end of a seat for the person to be massaged to sit in so as to be tiltable and positionable in place. The backrest  12  is covered with a fabric, cushion or the like. A description will be given below of a massage machine of the chair type wherein not only kneading balls  31 ,  31  can be held pushed out forward but a massage unit  20  itself is also made tiltable forward or rearward relative to the backrest  12  so that the kneading balls  31 ,  31  can be pushed out to a greater extent. 
   Inside Construction of the Backrest 
   As shown in  FIGS. 1 and 2 , the backrest  12  is provided inside thereof with a pair of opposite guide rails  14  extending upward or downward in parallel longitudinally of the backrest  12 . The guide rails  14 ,  14  are each in the form of a channel and arranged with their grooves opposed to each other. The opening side of each rail  14  has a rack  16  (see  FIG. 3 ). The massage unit  20  to be described later is upwardly or downwardly movably mounted on the guide rails  14 ,  14 . 
   With reference to  FIGS. 1 to 3 , the massage unit  20  has four rollers  23 ,  23 ,  65 ,  65  projecting from a main chassis  21  and fitting in the guide rails  14 ,  14  and is thereby made movable upward or downward. All components of the massage unit  20  are mounted on the main chassis  21 . 
   The main chassis  21  has rear and side openings and is fixedly provided at its center with longitudinal subchassis  22 ,  22  as spaced apart as shown in  FIGS. 3 and 4 . 
   The lower rollers  23 ,  23  are fitted to opposite ends of a up-and-down rotating shaft  24  extending through lower portions of the subchassis  22 ,  22  transversely of the machine and projecting from opposite sides of the main chassis  21 . Fixedly mounted on the rotating shaft  24  inwardly of the respective rollers  23 ,  23  are gears  25 ,  25  meshing with the racks  16 ,  16  of the guide rails  14 ,  14 . The rotating shaft  24  is coupled to an up-and-down motor  26  via a reduction device  27 . The gears  25 ,  25  meshing with the racks  16 ,  16  are rotated by driving the motor  26 , moving the massage unit  20  upward or downward along the guide rails  14 ,  14 . The combination of pulleys and a belt, or of a worm and worm wheel is usable to provide the reduction device  27 . The belt reeved around the pulleys of the reduction device  27  is not shown in  FIG. 4 . 
   Construction of Therapeutic Fingers, and Kneading and Tapping Mechanisms 
   With reference to  FIGS. 3 to 5 , therapeutic fingers  30 ,  30  for massaging the person to be treated are coupled to a kneading shaft  40  supported by the subchassis  22 ,  22  generally centrally thereof and to a tapping shaft  50  supported below the kneading shaft  40 . As shown in  FIGS. 3 and 4 , the kneading shaft  40  and the tapping shaft  50  are coupled to a kneading motor  41  and a tapping motor  51  mounted on the main chassis  21 , by way of reduction devices  42 ,  52 , respectively. The combination of pulleys and a belt, or of a worm and worm wheel is usable to provide the reduction device  42  between the kneading shaft  40  and the kneading motor  41 . The belt reeved around the pulleys of each of the reduction devices  42 ,  52  is not shown in  FIG. 4 . 
   With reference to  FIGS. 4 and 5 , the therapeutic fingers  30 ,  30  each comprise a pivotal lever  33  supported as inclined and positioned eccentrically on the kneading shaft  40  and projecting forward through a hole  21   a  formed in a front wall of the main chassis  21 , a massage arm  32  pivoted to the forward end of the pivotal lever  33  and bent at an obtuse angle at the midportion thereof, and kneading balls  31 ,  31   a  supported respectively at the upper and lower ends of the arm  32 . 
   As shown in  FIGS. 4 and 5 , eccentric cams  53 ,  53  which are out of phase with each other by 180 degrees are supported on the tapping shaft  50 . Each of the cams  53 ,  53  is connected by a rod  55  to a universal joint  54  attached to the rear end of the pivotal lever  33  which end is positioned toward the kneading shaft  40 . 
   The pivotal levers  33 ,  33  are supported as inclined on the kneading shaft  40  and connected to rods  55 ,  55  and prevented from rotating, so that when the kneading shaft  40  is rotated, the forward ends of the pivotal levers  33 ,  33  move lefiward and rightward. This movement pivotally moves the massage arms  32 ,  32  lefiward and rightward, reciprocatingly moving the upper kneading balls  31 ,  31 , as well as the lower kneading balls  31   a ,  31   a , toward or away from each other repeatedly for a kneading operation. 
   When the tapping motor  51  rotates, the rods  55 ,  55  eccentrically connected to the shaft  50  cause the therapeutic fingers  30 ,  30  to move upward and downward reciprocatingly for a tapping operation. 
   Pushing-out Mechanism  60   
   The massage unit  20  is provided with a pushing-out mechanism  60  for moving the unit  20  forward or rearward as shown in  FIGS. 1 and 2 . The pushing-out mechanism  60  comprises, for example, a crank mechanism  61  and a link mechanism  70  as will be described below. 
   With reference to  FIGS. 5 and 6 , the crank mechanism  61  comprises a crankshaft  62  disposed in front of the kneading shaft  40 , and crankpins  64 ,  64  (see  FIG. 5 ) rotatably carrying the upper rollers  65 ,  65  (see  FIG. 6 ) thereon and connected to the crankshaft  62  by crank arms  63 ,  63 . The crankpins  64 ,  64  are positioned eccentrically relative to the crankshaft  62 , so that when the crankshaft  62  is rotated, the crankpins  64  revolve about the crankshaft  62 . With the illustrated embodiment, the crankshaft  62 , the crank arms  63 ,  63  and crankpins  64 ,  64  are provided by a single metal rod, and the crankshaft  62  is supported on bearings  62   a ,  62   a  by the main chassis  21  as shown in.  FIG. 5 . 
   With reference to  FIG. 3 , the subchassis  22  is provided at upper and lower portions thereof with support pieces  22   a ,  22   a  each having a bearing  22   b . As shown in  FIGS. 3 ,  4  and  6 , a tilting threaded screw rod  67  is supported by the bearings  22   b ,  22   b . The tilting screw rod  67  has an upper end coupled to a pushing-out motor  69  by way of a reduction device  68  comprising pulleys and a belt (not shown in  FIG. 4 ). 
   A nut  71  is screw-thread engagement with the threaded portion of the screw rod  67 . The nut  71  can be made from a resin. As shown in  FIGS. 6 and 7 , the link mechanism  70  is connected to the resin nut  71 . The link mechanism  70  can be composed of a link  72  and a link piece  78 . 
   The link  72  will be described below with reference to an example of link  72  comprising a first link piece  73  and a second link piece  75  which are slidable relative to each other so as to be contractable longitudinally thereof. 
   The first link piece  73  is pivoted to the resin nut  71  and tiltable forward or rearward. A slide pin  74  projects from the first link piece  73  in the vicinity of a base end thereof. 
   The second link piece  75  comprises a pair of members holding the first link piece  73  therebetween and each having a slot  76  extending longitudinally thereof. The slots  76  of the second link piece  75  have slidably fitted therein the slide pin  74  of the first link piece  73 . 
   Further as shown in  FIG. 6 , the second link piece  75  has a pin  75   a  projecting from the forward end thereof. A spring  77  extends between and is engaged with the slide pin  74  and the pin  75   a . The spring  77  biases the second link piece  75  toward the resin nut  71 . When free of any load, the second link piece  75  is pulled closest to the resin nut  71  by the spring  77 . 
   The link piece  78 , i.e., third link piece  78 , is supported by the pin  75   a  of the second link piece  75 . The third link piece  78  is bent forward at its midportion and has one end secured to the crankshaft  62 . 
   When the resin nut  71  is positioned at an upper portion of the tiling screw rod  67 , the third link piece  78  is pulled toward the second link piece  75 , bringing the massage unit  20  (main chassis  21 ) to the most retracted position (see  FIG. 1 ). 
   When the resin nut  71  is moved down from this position as shown in  FIG. 7  (toward the direction of arrow A in  FIG. 7 ) by rotating the tilting screw rod  67 , the second link piece  75  pulls down the portion of the third link piece  78  engaging with the piece  75 , rotating the third link piece  78  about the crankshaft  62 . Since the third link piece  78  is secured to the crankshaft  62 , the crankshaft  62  rotates with the third link piece  78 . 
   The crankpins  64 ,  64  at the opposite ends of the crankshaft  62  are movable only along the guide rails  14 ,  14  by the rollers  65 ,  65  and are unable to move forward or rearward, so that the rotation of the crankshaft  62  tilts the massage unit  20  about the up-and-down rotating shaft  24 . With the rotating shaft  24  provided below the massage unit  20 , the tilting of the unit  20  pushes out the therapeutic fingers  30 ,  30  forward as shown in  FIG. 2  (as indicated by the arrow B in  FIG. 7 ). 
   By pushing out the fingers  30 ,  30  at the position of the shoulders of the person to be massaged, the fingers  30 ,  30  reach the upper portions of the shoulders. The upper portions of the shoulders of the person can be effectively massaged by driving the kneading motor  41  and/or the tapping motor  51  in this state. 
   When the fingers  30 ,  30  as positioned at a level lower than the shoulders of the person, i.e., at the position of the back or waist, are pushed out, the back or waist of the person can be massaged with the pressure of the fingers. Further a rolling massage can be given with the fingers  30 ,  30  pressed against the person to be treated with a great force, by driving the up-and-down motor  26  to move the massage unit  20  upward and downward. 
   When the tilting screw rod  67  is reversely rotated in the state shown in  FIG. 2 , the resin nut  71  moves upward to conversely retract the massage unit  20  and pull back the fingers  30 ,  30  inwardly of the backrest (see  FIG. 1 ). In the retracted state, a massage can be given in the same manner as conventionally. 
   The amount of pushing-out of the massage unit  20  is controllable by rotating the tilting screw rod  67 , namely by adjusting the position of the resin nut  71  relative to the screw rod  67 . The maximum amount of pushing-out is also controllable by altering the length of the crank arms  63 ,  63 . 
   The amount of pushing-out of the massage unit  20  is detectable by pushing-out sensor means  79 . As the sensor means  79 , for example, a variable resistor  79  is disposed in contact with the third link piece  78  as shown in  FIG. 6  to measure variations in the resistance value involved in the angle of rotation of the third link piece  78  by the resistor  79 . 
   The crankshaft  62 , which rotates with the third link piece  78 , may be provided with the pushing-out sensor means  79 . 
   Other Embodiment of Link Mechanism  70   
   With the foregoing embodiment, the resin nut  71  is connected to the crankshaft  62  by the link mechanism  70  which comprises the link  72  wherein the second link piece  75  is biased by a spring and slidable relative to the first link piece  73 , and the third link piece  78  coupled to the link  72 . The first link piece  73  and the second link piece  75  are made slidable relative to each other so as to render the therapeutic fingers  30 ,  30  (massage unit  20 ), as pushed out forward, slightly retractable when subjected to a force from the front. Consequently, when the person to be massaged forces his or her back against the backrest  12  with the fingers  30 ,  30  pushed out, a great rearward force acts on the fingers  30 ,  30  to retract the massage unit  20 . This removes the pain to be otherwise given to the person. 
   If the above effect need not be produced, the third link piece  78  may be coupled directly to the resin nut  71  by a single piece of link  72  instead of providing separate pieces for use as the first link piece  73  and the second link piece  75 . 
   Since the amount of sliding movement of the second link piece  75  relative to the first link piece  73  corresponds to the force to be applied to the therapeutic fingers  30 ,  30 , means  79   a  can also be provided for detecting the particular part of the body of the person to be massaged with which the fingers  30 ,  30  are in contact, based on the amount of sliding movement of the second link piece  75 . In this case, the amount of sliding movement is detectable by a variable resistor  79   a  or the like which is provided for the first link piece  73  so as to be in contact with the second link piece  75  as shown in  FIG. 6 . 
   When the fingers  30 ,  30  out of contact with the person to be massaged are brought into contact with the shoulders of the person to be massaged, by lowering the massage unit  20  from a position above the backrest  12 , an upward force will act on the fingers  30 ,  30 . 
   As a result, the second link piece  75  slidingly moves upward against the force of the spring  77 . The amount of sliding movement of the second link piece  75  is detected by the variable resistor  79   a . The value of detection indicates that the position if the shoulders of the person. 
   Arm Lock Mechanism  80   
   An arm lock mechanism  80  will be described below which serves to project the therapeutic fingers  30 ,  30  forward with the pushing out of the massage unit  20 . 
   With reference to  FIG. 7 , the arm lock mechanism  80  comprises arm lock rod  83 ,  83  each of which couples the bent portion of the massage arm  32  to the crankshaft  62  by universal joint  81 ,  82 . The universal joint  82  for the crankshaft  62  is provided at such a position that when the massage unit  20  is in the most projected position (see  FIG. 2 ), the upper kneading ball  31  on the massage arm  32  can be pushed out to the foremost position. The universal joint  82  is positioned also away from the axis of the crankshaft  62 . The universal joint  81  for the massage arm  32  is provided at a position away from the position where the massage arm  32  is supported by the pivotal lever  33 . 
   As the massage unit  20  is pushed out as described above by rotating the crankshaft  62 , the universal joint  82  rotates with the rotation of the shaft  62 , pushing the arm lock rod  83  upward while tilting the rod. As a result, the arm lock rod  83  rotates the massage arm  32  forward, causing the upper kneading ball  31  to project forward relative to the main chassis  21  from a state in which the upper and lower kneading balls  31 ,  31   a  are generally in parallel to the backrest  12 . 
   In addition to the pushing-out of the massage unit  20  by the pushing-out mechanism  60  described, the kneading ball  31  is thus pushed out greatly to the upper portion of the shoulder to massage the shoulder effectively. 
   A massage can be given by kneading and/or tapping with the upper kneading balls  31  thus projected, by rotating the kneading shaft  40  and/or the tapping shaft  50  in this state. 
   When the above operation is performed with the therapeutic fingers  30 ,  30  in bearing contact with the back or waist of the person to be massaged, a finger-pressure massage can also be given by the upper kneading balls  31 . 
   Further when the massage unit  20  is retracted by rotating the crankshaft  62  reversely, each universal joint  82  pulls the arm lock rod  83  downward conversely to the above movement. As a result, the arm lock rod  83  rotates the massage arm  32  rearward to return the upper and lower kneading balls  31 ,  31   a  to the position generally in parallel to the backrest  12  for the balls to perform a massage in the usual manner. 
   Apparently, the present invention can be modified or altered by one skilled in the art without departing from the spirit of the invention, and such modifications are included within the scope of the invention as set forth in the appended claims.