Patent Publication Number: US-2007106185-A1

Title: Portable body massager

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application is a continuation-in-part of U.S. application Ser. No. 10/836,905; filed Apr. 30, 2004, now U.S. Pat. No. 7,128,721. 
    
    
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to massagers, particularly to portable body massagers.  
      2. Background Art  
      The prior art includes body massagers provided within chairs, as well as in portable cushions. These prior art body massagers commonly include a track or guide for moving a massage assembly longitudinally within the chair or cushion. The prior art body massagers are relatively complex and utilize many components, thereby requiring sufficient structure to support the massager and limiting the portability of the massager. Due to the complexities of conventional body massagers, a consumer&#39;s ability to procure such massagers is limited due to value and affordability.  
      For example, many prior art body massagers include a complex guide system and frame thereby requiring a housing that is sufficiently robust, such as a chair. Many prior art body massagers require two motors, one for translating the massage mechanism, and the other for imparting the massage effect from the massage mechanism. Accordingly, these drawbacks of the prior art add both cost and weight to the prior art body massagers.  
      A goal of the present invention is to provide a simplified body massager having improvements in massage function, portability and cost in view of the prior art. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view of a first embodiment body massager in accordance with the present invention;  
       FIG. 2  is an exploded perspective view of a backrest region of the body massager of  FIG. 1 ;  
       FIG. 3  is a front side elevation view of the backrest region of the body massager of  FIG. 1 , illustrated with a portion of a housing thereof partially removed;  
       FIG. 4  is an enlarged, front side elevation view of a carriage of the body massager of  FIG. 1 , illustrated within the backrest housing of the body massager with a cover plate removed therefrom;  
       FIG. 5  is an exploded perspective view of a seat support region of the body massager of  FIG. 1 ;  
       FIG. 6  is a front side elevation view of a backrest region of another embodiment body massager in accordance with the present invention;  
       FIG. 7  is a front side elevation view of the backrest region of the body massager of  FIG. 6 , illustrated with a portion of a housing thereof partially removed;  
       FIG. 8  is an enlarged, front side elevation view of a carriage of the body massager of  FIG. 6 , illustrated within the backrest housing of the body massager;  
       FIG. 9  is another enlarged, front side elevation view of the carriage of the body massager of  FIG. 6 , illustrated within the backrest housing of the body massager with a cover plate removed therefrom;  
       FIG. 10  is yet another enlarged, front side elevation view of the carriage of the body massager of  FIG. 6 , illustrated within the backrest housing of the body massager, partially disassembled for depicting a portion of a transmission of the carriage; and  
       FIG. 11  is another enlarged, front side elevation view of the carriage of the body massager of  FIG. 6 , illustrated within the backrest housing of the body massager, partially disassembled for depicting another portion of the transmission. 
    
    
     DESCRIPTION OF EMBODIMENTS OF THE INVENTION  
      As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale, and some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for the claims and/or as a representative basis for teaching one skilled in the art to variously employ the present invention.  
      With reference to  FIG. 1 , a first embodiment body massager is illustrated in accordance with the present invention and is referenced generally by numeral  10 . The body massager  10  includes a backrest region  12  and a seat support region  14 . The internal assemblies of the backrest region  12  and the seat support region  14  are collectively retained within a flexible cover  16 , which is formed of a high quality vinyl. Of course other materials such as leather may be employed for the cover  16 . The cover  16  provides a pivotal connection  18  at a lower longitudinal end of the backrest region  12  and a rearmost end of the seat support region  14 . The flexible material of the cover  16  provides a living hinge at the pivotal connection  18  permitting user adjustment of an included angle between the backrest region  12  and the seat support region  14 .  
      Massage effects provided by the body massager  10  include a kneading massage effect provided in the backrest support  12 , which is operable to provide the kneading massage effect longitudinally along the length of the backrest region  12 . The seat support region  14  provides a vibratory massage effect to the user seated thereupon.  
      The backrest region  12  is sized to be received upon a backrest of a conventional chair. Likewise, the seat support region  14  is sized to be received upon a seat support of a conventional chair. Additionally, the body massager  10  is portable due to its compact size and light weight so that the user may place the body massager  10  upon a conventional chair for receiving a massage when seated upon the chair. The adjustability of the included angle between the backrest region  12  and the seat support region  14  accommodates a wide range of angles that may be incorporated in conventional chairs.  
      The backrest region  12  includes a height and width corresponding to the conventional chair and has a thickness that is adequate for housing the massage assembly therein while avoiding disruption of comfort and support provided by the underlying chair. Likewise, the seat support region  14  has a width and a depth corresponding to that of the conventional seat support and has a thickness that is adequate for housing the associated massage assembly while avoiding disruption of comfort and support provided by the underlying chair. Additionally, the backrest region  12  includes a pair of straps  20  mounted from its lateral sides for securing the body massager  10  to the conventional chair. The straps  20  each include one of a hook and loop material for securing the straps  20  about the backrest of the conventional chair. Of course, any engagement mechanism is contemplated, such as a belt buckle, a clip or the like.  
      By way of example, the backrest region  12  has a height of approximately twenty-five inches, an overall width of approximately eighteen inches, and a thickness of approximately two and a half inches. Also, by way of example, the seat support region  14  has a width of approximately sixteen and a half inches, a depth of approximately fourteen and a half inches, and a thickness of approximately one and three quarter inches. Of course, the invention contemplates that the body massager may have dimensions adequate to be received by any conventional chair. However, the dimensions of the first embodiment are suitable for most conventional chairs.  
      The seat support region  14  includes a seating surface  22  provided thereon for receiving the user when seated. The backrest region  12  includes a backrest surface  24  for receiving and supporting the back of the user thereupon. The massage assemblies of the backrest region  12  and the seat support region  14  impart the respective massage effects through the backrest surface  24  and seating surface  22  respectively. The cover  16  includes a removable flap  26  mounted to the backrest region  12  along the backrest surface  24 . The flap  26  is removably attached by hook and loop material so that the user may remove the flap  26  and expose a woven fabric (not shown). The flexible material of the flap  26  includes dampening characteristics which reduce the massage effect imparted to the backrest surface  24 . Accordingly, the user may remove the flap  26  to increase the massage intensity.  
      The body massager further includes a remote  28  connected thereto for controlling the operations of the massager  10 . The cover  16  has a pocket  30  mounted to a lateral side of the seat support region  14 . The pocket  30  has an opening provided in its rearward end so that the remote  28  may be conveniently retained when not in use.  
      With reference now to  FIGS. 2-4 , the backrest region  12  is illustrated in greater detail. The backrest region  12  includes a two piece housing provided by an upper housing portion  32  and a lower housing portion  34 . The upper housing portion  32  and the lower housing portion  34  are sized and adaptable to be secured together by a plurality of fasteners  36  for retaining components of a massage assembly  38  therein. The massage assembly  38  includes a carriage  40  which cooperates with the lower housing portion  34  for limited longitudinal translation within the backrest region  12 . Accordingly, the lower housing portion  34  includes a longitudinal guide  41  mounted therein for cooperating with the carriage  40 . The longitudinal direction y is illustrated in  FIG. 2  and the housing includes a longitudinal axis y L . The guide  41  includes a series of gibs indicated and referenced as upper gib  42 , central gib  44  and lower gib  46 . The gibs,  42 ,  44 ,  46  of the lower housing portion  34  cooperate with and retain a first longitudinal key  48  formed laterally along the carriage  40 . The carriage  40  includes a second longitudinal key  50  formed laterally thereupon in transversely spaced opposition to that of the first key  48 . A transverse direction x is illustrated in  FIG. 2 . The second key  50  is retained relative to the lower housing portion  34  by an elongate retainer gib  52  which is secured to the lower housing portion  34  by a series of fasteners  54 .  
      The guide  41  of the lower housing portion  34  further comprises a pair of longitudinal rails  56 ,  56 ′ provided within the lower housing portion  34  and extending upward therefrom. A pair of keyways  58 ,  58 ′ are formed longitudinally through the carriage  40 . The keyways  58 ,  58 ′ are sized to receive the rails  56 ,  56 ′, respectively. The cooperation of the rails  56 ,  56 ′ and keyways  58 ,  58 ′ provides transverse guidance and support to the carriage  40  as it translates along the guide  41 . The carriage  40  includes a plurality of roller bearings  60 , which are each pivotally connected to the carriage  48  and are offset from the keyways  58 ,  58 ′ and adjacent thereto for engaging a bearing surface provide upon each rail  56 ,  56 ′. As the carriage  40  translates along the guide  41 , the carriage  40  is bearingly supported by the roller bearings  60  as they engage the surfaces provided by the rails  56 ,  56 ′.  
      The lower housing portion  34  includes a series of ribs  62  formed therein for providing cross support to the lower housing portion  34  and the gibs  42 ,  44 ,  46 ,  52 . Accordingly, the two piece housing  32 ,  34  provides both a housing and a structural frame for the massage assembly  38 . Both housing portions  32 ,  34  are each formed from an injection molding process or the like to provide low weight, yet rigid structural members. Additionally, the upper gib  42 , central gib  44 , lower gib  46  and rails  56 ,  56 ′ are integrally formed with the lower housing portion  34  thereby enhancing rigidity and structural cooperation therebetween and minimizing costs in components and assembly.  
      The upper housing portion  32  has a peripheral contour that exceeds the overall dimensions of the lower housing portion  34 . This feature is to provide broad lateral support to the user that is distributed directly to the lower housing portion  34 . A pair of lateral cushions  64 ,  64 ′ are each adhered to lateral undersides of the upper housing portion  32  to provide an overall thickness of the two piece housing that is generally uniform. Additionally, another cushion (not shown) is provided within the cover  16  and attached therein. The cushion is oriented to engage the top side of the upper housing portion  32  about its periphery for providing padded comfort and support to the user as the user rests its back against the backrest surface  24 . The cushion is provided within the cover  16  rather than being adhered atop the upper housing portion  32  to permit access to the fasteners  36  that fasten the housing portions  32 ,  34  together.  
      The massage assembly  38  includes a motor  66 , which is mounted to the carriage  40  and retained by a cover plate  68 . The cover plate  68  and the carriage  40  collectively define a motor mount for the motor  66  and are fastened together by a plurality of fasteners  70 . The motor  66  is operable to impart a massage effect from the massage assembly  38  and translate the carriage  40  along the guide  41  of the lower housing portion  34 . The motor  66  includes a motor output shaft  72  extending from the motor  66  and driven thereby. A worm  74  is provided on the motor output shaft  72  and fixed relative to the shaft by a fastener  76 . The worm  74  drives a pair of worm gears  78 ,  78 ′ in opposed rotational directions. Each worm gear  78 ,  78 ′ is secured to a gear shaft  80 ,  80 ′ by a fastener  82 ,  82 ′. The gear shafts  80 ,  80 ′ are each rotatably connected to the carriage  40  and the cover plate  68  so that the worm  74  drives the worm gear  78 ,  78 ′ in opposite rotary directions relative one another in a reduced rotation from that of the motor  66 . The gear shafts  80 ,  80 ′ extend in direction z, which is perpendicular to both the longitudinal direction y and the transverse direction x.  
      Each gear shaft  80 ,  80 ′ extends through the cover plate  68  and receives a massage bracket  84 ,  84 ′, which are each fastened to the respective gear shaft  80 ,  80 ′ by a fastener  86 ,  86 ′. The massage brackets  84 ,  84 ′ are transversely spaced about the longitudinal axis y L . Each massage bracket  84 ,  84 ′ includes a first massage hemispherical node  88 ,  88 ′ and a second hemispherical massage node  90 ,  90 ′ mounted to the respective bracket.  
      The gear shafts  80 ,  80 ′ are oriented perpendicular to the guide  41  and extend in the z direction towards the backrest surface  24 . The massage nodes  88 ,  88 ′,  90 ,  90 ′ each rotate relative to the respective massage bracket  84 ,  84 ′ about an axis that is offset from that of the respective gear shaft  80 ,  80 ′. The massage nodes  88 ,  88 ′,  90 ,  90 ′ extend through a corresponding aperture  92 ,  92 ′ formed through the housing upper portion  32  for imparting the massage effect to the user through the cover  16 . As the massage nodes  88 ,  88 ′,  90 ,  90 ′ revolve around the corresponding gear shaft  80 ,  80 ′ a rotary kneading massage effect is imparted upon the user, which is commonly referred to as a Shiatsu massage.  
      Each massage node  88 ,  88 ′,  90 ,  90 ′ is rotatably connected to the corresponding massage bracket  84 ,  84 ′ to reduce friction generated in the rotary kneading massage effect. Further, each massage node  88 ,  88 ′,  90 ,  90 ′ is axially translatable relative to the corresponding massage bracket  84 ,  84 ′ and is urged to an extended position in the z direction by a spring  93  ( FIG. 2 ) retained between the corresponding massage node  88 ,  88 ′,  90 ,  90 ′ and the respective massage bracket  84 ,  84 ′. The springs  93  ( FIG. 2 ) cause the massage nodes  88 ,  88 ′,  90 ,  90 ′ to extend and engage the user, yet permit the respective massage node  88 ,  88 ′,  90 ,  90 ′ to be urged to a retracted position upon a load provided by the user resting thereagainst thereby enhancing the kneading massage effect by adding axial compliancy to the operation of the rotary massage effect.  
      Additionally, the first massage nodes  88 ,  88 ′ have an overall height in the z direction greater than that of the second massage nodes  90 ,  90 ′ to extend further from the corresponding massage brackets  84 ,  84 ′. The first massage nodes  88 ,  88 ′ also have a diameter greater than that of the second massage nodes  90 ,  90 ′. These variations are utilized for varying the engagement of the rotary kneading effect with the user, resulting in a kneading effect that is nonsymmetrical and similar to a massage provided by the hands of a skilled massage therapist.  
      The apertures  92 ,  92 ′ formed through the upper housing portion  32  are generally elongate for permitting the massage nodes  88 ,  88 ′,  90 ,  90 ′ to pass therethrough as the carriage  40  is translated relative to the guide  41 . Further, the cover plate  68  includes a roller bearing  94  pivotally connected thereto for engaging an underside bearing surface formed within the upper housing portion  32 , thus providing bearing support between the carriage  40  and the upper housing portion  32 . Accordingly, loading imparted upon the backrest surface  24  is translated through the upper housing portion  32  to the carriage  40  through roller bearing  94 , to the lower housing portion  34  through the roller bearings  60  for providing bearing support therebetween and preventing such loading from inhibiting the translation of the carriage  40  along the guide  41 .  
      A first pinion gear  96  is mounted upon gear shaft  80 ′ between the worm gear  78 ′ and the carriage  40  for being driven by rotation imparted upon the worm gear  78 ′. A first reduction gear  98  is rotatably mounted upon an intermediate shaft  100  that is supported by the carriage  40  for rotation about an axis in the z direction. A second pinion gear  102  is secured to the first reduction gear  98  and driven by the rotation imparted upon the first reduction gear  98 . The second pinion gear  102  is engaged with a second reduction gear  104 . The second reduction gear  104  is rotatably coupled to the carriage  40  about a shaft  106 , which is supported between the carriage  40  and the cover plate  68  for rotation about an axis in the z direction. A third pinion gear  108  is secured to the second reduction gear  104  and oriented about the shaft  106  between the second reduction gear  104  and the carriage  40 . The third pinion gear  108  is engaged to a gear rack  110  formed along the retainer gib  52 .  
      The worm  74 , worm gear  78 ′, first pinion gear  96 , first reduction gear  98 , second pinion gear  102 , second reduction gear  104 , third pinion gear  108  and gear rack  110  provide a transmission such that rotation from the motor output shaft  72  experiences three stages of reduction for reduced rotation of the third pinion gear  108  relative to the motor output shaft  72  and two stages of reduction relative to the massage nodes  88 ,  88 ′,  90 ,  90 ′. Since the rack  110  is fixed relative to the guide  41 , rotation of the third pinion  108  translates the carriage  40  along the guide  41 . Accordingly, the rotation of the motor output shaft  72  results in both a rotary kneading massage effect and translation of the carriage along the guide due to the engagement with the gear rack  110 .  
      Due to the translation of the carriage  40  and the motor  66 , cord management is necessary to ensure that a power cord  112 , which provides power to the motor  66  does not interfere with, nor get damaged by the operations of the massage assembly  38 . Accordingly, a longitudinal bar  114  is provided within the backrest region  12  mounted to the lower housing portion  34 . The power cord  112  is coiled about the bar  114  for extension and retraction thereabout as the carriage  40  is translated along the guide  41 .  
      The motor  66  is directly coupled to the associated transmission for translation of the carriage  40  when the motor  66  is powered. In order to reverse direction of the carriage  40 , the rotational direction of the motor  66  is reversed as well. In order to control the reversal of power to the motor  66 , a series of limit switches  116   a - 116   f  are provided along the guide  41 . Each limit switch  116   a - 116   f  includes a leaf spring which extends in an unloaded position thereof. Upon actuation of each leaf spring, the respective limit switch  116   a - 116   f  sends a signal indicating the actuation. Accordingly, the limit switches  116   a - 116   f  are each oriented so that the associated leaf spring extends into the path of travel of the carriage  40  for actuation thereby. The signals provided by the limit switches  116   a - 116   f  are processed by a central processing unit provided at a circuit board  118 , mounted within the backrest region  12  to the lower housing portion  34  as illustrated in  FIG. 3 .  
      The user operates the remote  28  to select a desired target range of massage to be imparted to the user&#39;s back. The range selected on the remote  28  is processed so that a pair of limit switches  116   a - 116   f  provide the range of travel of the carriage  40 . For example, if the user selects a range of massage associated with the entire back, the limit switches  116   a - 116   f  control this operation. For example, referring to  FIG. 3 , with the carriage  40  in a position which actuates the limit switch  116   a , the motor  66  begins a rotation which provides a rotary kneading massage effect rotating the massage nodes  88 ,  88 ′,  90 ,  90 ′ and translates the carriage  40  along the guide  41  towards the limit switch  116   f . Upon the carriage  40  actuating the limit switch  116   f , a signal is sent to the central processing unit, which consequently reverses the rotation of the motor  66 . The reversed rotation of the motor  66  provides a reversed rotation of the rotary kneading massage and translates the carriage  40  towards the limit switch  116   a.    
      Various ranges of massages are provided by the series of limit switches  116   a - 116   f  so that the user may target desired regions of massage upon the back of the user.  
      In order to simplify the manufacture of the backrest region  12 , the limit switches  116   a - 116   f  are each adhered to the housing lower region  34  by resistance welding, friction welding, adhesives or the like.  
      Briefly, the kneading massage effect is generated from the simplified massage assembly  38  and corresponding support frame and guide  41 . Accordingly, the kneading massage effect is provided within the body massager  10  without limiting the portability and weight of the massager  10 . Additionally, the motor  66  is provided upon the carriage  40  to overcome shortcomings of prior art kneading massagers that require either two motors to provide both a massage effect and translation of the massage effect or a complex drive system for providing both effects, which commonly requires a heavy duty frame for supporting the complex drive system.  
      Referring now to  FIG. 5 , the seat support region  14  is illustrated without the cover  16  and is partially exploded. The seat support region  14  comprises a seat support housing defined by a unitary cushion  120  for providing comfort and resilient support to the user. The cushion  120  includes a pair of vibratory massage assemblies  122 ,  122 ′ housed therein. The cushion  120  has a pair of recesses  124 ,  124 ′ formed in its underside illustrated in hidden for receiving each of the respective vibratory massage assemblies  122 ,  122 ′. Each vibratory massage assembly  122 ,  122 ′ includes a motor  126 ,  126 ′ for imparting rotary motion to an eccentric weight  128 ,  128 ′ for generating an invigorating vibratory massage effect upon the cushion  120 , which is received by the user seated thereupon. The vibratory massage assemblies  122 ,  122 ′ are spaced transversely apart relative one another to distribute the massage effect upon the cushion  120 .  
      Each vibratory massage assembly  122 ,  122 ′ includes a bracket  130 ,  130 ′ for securing the respective assembly to the underside of the cushion. Specifically, each bracket  130 ,  130 ′ may be adhered to the underside of the cushion  120  by an adhesive. Each vibratory massage assembly  122 ,  122 ′ includes a motor mount bracket  132 ,  132 ′ for securing the respective motor  126 ,  126 ′ to the corresponding bracket  130 ,  130 ′.  
      The operation of the vibratory massage assemblies  122 ,  122 ′ is controlled by the remote  28 . Therefore, the vibratory massage effect may be imparted to the user alone or in combination with the rotary kneading massage effect. By way of example, the operation of the vibratory massage assemblies  122 ,  122 ′ includes a steady massage, wherein both vibratory massage assemblies  122 ,  122 ′ provide a consistent vibratory massage effect to the user. Additionally, a tapping massage effect is provided wherein both vibratory massage assemblies are operated synchronously with a common direction of rotation relative to another so that the user experiences a vibratory massage effect that is generally enhanced rather than merely vibrating. Additionally, a side to side vibratory massage effect is provided wherein each vibratory massage assembly  122 ,  122 ′ cycles alternatingly so that the user experiences a vibratory massage effect that is directed from one of the vibratory massage assemblies  122  to the other  122 ′. The remote  28  provides control of the intensity of the vibratory massage effect such as low, medium and high wherein the intensity is a result of the speed of the motors  126 ,  126 ′.  
      In summary, the body massager  10  provides an efficient, portable, lightweight, sturdy massage apparatus which generates two types of massage to two areas of the body with operational variations thereof so that the user may experience a variety of massage effects or a desired targeted massage effect, while minimizing the costs of the overall massager.  
      Referring now to  FIG. 6 , another embodiment backrest region is illustrated in accordance with the present invention and is referenced generally by numeral  140 . The backrest region  140  is illustrated without a cover, such as the cover  16  ( FIG. 1 ), which is removed for revealing components of the backrest region  140 . The backrest region  140  may be utilized as a seatback cushion and massager, or may include a seat support region, such as seat support region  14  ( FIG. 1 ), for a seat support cushion and/or a massager.  
      As depicted in  FIG. 6 , the backrest region  140  includes an upper housing portion  32  and a lower housing portion  142 . The upper housing portion  32  includes a pair of apertures  92 ,  92 ′ so that a massage effect may be imparted by a massage assembly  144  through the upper housing portion  32  to a body part of the user.  
      With reference to  FIGS. 6-8 , the massage assembly  144  includes a carriage  146  mounted to a longitudinal guide  148  of the lower housing portion  142  for limited longitudinal translation of the carriage  146  along the guide  148 . Similar to the prior embodiment, the massage assembly  144  includes a pair of transversely spaced apart massage brackets  150 ,  150 ′, each rotatably connected to the carriage  146 . Each massage bracket  150 ,  150 ′ is provided with a first massage node  152 ,  152 ′, a second massage node  154 ,  154 ′, and a third massage node  156 ,  156 ′ rotatably connected to the respective massage bracket  150 ,  150 ′. The apertures  92 ,  92 ′ in the upper housing portion  32  permit the massage nodes  152 ,  152 ′,  154 ,  154 ′,  156 ,  156 ′ to extend from the carriage  146  for engagement with the user.  
      The massage brackets  150 ,  150 ′ are rotated relative to the carriage  146  such that the massage nodes  152 ,  152 ′,  154 ,  154 ′,  156 ,  156 ′ provide a rotary kneading massage effect to the user. Additionally, the massage nodes  152 ,  152 ′,  154 ,  154 ′,  156 ,  156 ′ of each massage bracket  150 ,  150 ′ vary in height and diameter for providing a massage effect that varies in contact and engagement to replicate a manual kneading massage effect from a skilled massage therapist. Additionally, the larger massage nodes, namely the first and second massage nodes  152 ,  152 ′,  154 ,  154 ′, of each massage bracket  150 ,  150 ′ are axially translatable and are provided with springs, such as springs  93  ( FIG. 2 ), for providing axial compliancy to the massage nodes  152 ,  152 ′,  154 ,  154 ′ and the associated massage effect. The third massage nodes  156 ,  156 ′ may provide an ancillary massage effect, such as heat, or any other suitable ancillary effect, as is known in the art.  
      The guide  148  includes a series of gibs which are referenced and indicated in  FIG. 7  as a left upper gib  158 , a left central gib  160 , a left lower gib  162 , a right upper gib  164 , a right central gib  166  and a right lower gib  168 . Referring now to  FIG. 8 , the carriage  146  includes an opposed pair of keys  170 ,  172  extending laterally outboard from the carriage  146  and retained below the gibs  158 ,  160 ,  162 ,  164 ,  166 ,  168  for retaining the carriage  146  within the lower housing portion  142  as the carriage  146  translates. The left upper gib  158 , left central gib  160 , left lower gib  162 , right upper gib  164 , and right central gib  166  are formed integrally with the lower housing portion  142 , for example by an injection molding process of a polymeric material. The right lower gib  168  is formed separately to permit the insertion of the keys  170 ,  172  into the gibs  158 ,  160 ,  162 ,  164 ,  166  during assembly. Subsequently, the right lower gib  168  is fastened to the lower housing portion  142 .  
      The carriage  146  includes a cover plate  174 . A roller bearing  176  is mounted for rotation to the cover plate  174 . The roller bearing  176  engages an underside of the upper housing portion  32  so that loads, such as the weight of a body part, that are applied to the upper housing portion  32  are distributed to the carriage  146  through the roller bearing  176  to reduce friction between the carriage  146  and the upper housing portion  32 . The cover plate  174  also provides a part of a motor mount for a motor  178  that is retained within the carriage  146 .  
       FIG. 9  illustrates the carriage  146  with the cover plate  174  removed. The motor  178  includes a motor output shaft  180  that is driven for rotation by the motor  178 . A worm  182  is mounted to the motor output shaft  180  and extends between and into engagement with a pair of transversely spaced worm gears  184 ,  186 . Each worm gear  184 ,  186  is mounted to a gear shaft  188 ,  190 , which are each rotatably mounted in the carriage  146 . The gear shafts  188 ,  190  each extend through the cover plate  174 . The massage brackets  150 ,  150 ′ are each mounted to a distal end of one of the gear shafts  188 ,  190  external of the cover plate  174 . Thus, when the motor  178  drives the motor output shaft  180 , the worm  182  drives the worm gears  184 ,  186  for driving the gear shafts  188 ,  190  and consequently driving the massage brackets  150 ,  150 ′ and the corresponding massage nodes  152 ,  152 ′,  154 ,  154 ′,  156 ,  156 ′, for generating a rotary kneading massage effect. Since the worm  182  drives both worm gears  184 ,  186 , the left worm gear  184  is driven in reverse rotation than that of the right worm gear  186  for providing a uniform rotary massage effect.  
      The motor  178  also drives the carriage  146  along the guide  148 . A first spur gear  192 , shown hidden in  FIG. 9 , is mounted to the right gear shaft  190  beneath the right worm gear  186  and the first spur gear  192  is consequently driven for rotation with the right worm gear  186 . A first reduction gear  194  is mounted for rotation in the carriage  146  and engaged with the first spur gear  192  for being driven in a reduced rotation. Referring now to  FIG. 10 , a second spur gear  196 , illustrated in hidden, is mounted to the first reduction gear  194 , beneath the first reduction gear  194  for rotation with the first reduction gear  194 . A second reduction gear  198  is also mounted for rotation in the carriage  146 , and is engaged with the second spur gear  196  for being driven in a reduced rotation by the second spur gear  196 .  
      With reference now to  FIG. 11 , a third spur gear  200  is illustrated that is mounted for rotation in the carriage  146 . The third spur gear  200  is coupled to the second reduction gear  198  and rotates with the second reduction gear  198 . The third spur gear  200  is engaged with a first pinion gear  202  that is also mounted for rotation in the carriage  146 . The first pinion gear  202  engages a longitudinal gear rack  204  that is secured within the lower housing portion  142 . The third spur gear  200  drives a fourth spur gear  206  that is mounted for rotation in the carriage  146 . The fourth spur gear  206  drives a second pinion gear  208  that is mounted for rotation in the carriage  146 . The second pinion gear  208  engages a second longitudinal gear rack  210  that is fastened to the lower housing portion  142 . The rotation of the pinion gears  202 ,  208  causes the carriage  146  to translate along the guide  148 .  
      Referring again to  FIG. 9 , the operation of the transmission of the massage assembly  144  is illustrated beginning with the motor  178 . As the motor  178  drives the motor output shaft  180  and worm  182  in a counter-clockwise direction when viewed axially and referenced by the arcuate arrow, the left worm gear  184  rotates clockwise; and the right worm gear  186  and the first spur gear  192  rotate counter-clockwise. The first spur gear  192  therefore drives the first reduction gear  194  in a clockwise direction.  
       FIG. 10  illustrates the first reduction gear  194  and the second spur gear  196  rotating clockwise, thereby driving the second reduction gear  198  counter-clockwise. The third spur gear  200  rotates counter-clockwise with the second reduction gear  198 . In  FIG. 11 , the third spur gear  200  drives the first pinion gear  202  clockwise in engagement with the first rack  204  to drive the carriage  146  in an upward direction in  FIG. 11 . The fourth spur gear  206  is utilized between the third spur gear  200  and the second pinion gear  208 , so that the fourth spur gear  206  rotates clockwise and therefore the second pinion gear  208  rotates counter-clockwise, which is the opposite direction of the first pinion gear  202 , thereby also driving the carriage  146  upward due to the engagement with the second rack  210 . Thus the fourth spur gear  206  is sized so that the second pinion gear  208  rotates at the same rate as the first pinion gear  202 .  
      Moreover, the transmission of the massage assembly  144  provides a reduced rotation from the motor  178  to the massage brackets  150 ,  150 ′, and an even further reduced rotation from the motor  178  to the pinion gears  202 ,  208  so that a rotary kneading massage is imparted upon the user as the carriage  146  translates along the guide  148 . A reversed rotation of the motor results in a reversed rotary kneading massage effect and a reversed translation of the carriage  146  due to a reversal of the massage components, which is opposite of the rotary directions depicted in  FIGS. 9-11 .  
      By utilizing a pair of gear racks  204 ,  210 , even loading of the carriage  146  is applied thereby providing a stabilized translation of the carriage  146 . Thus, the driving torque for translating the carriage  146  is distributed through the spaced pair of pinion gears  202 ,  208  for evenly actuated translation of the carriage  146 .  
      The carriage  146  has a transverse pair of keyways  212 ,  214  formed through the carriage  146 . Each of the keyways  212 ,  214  is aligned with one of the gear racks  204 ,  210  so that the gear racks  204 ,  210  also provide lateral guide support to the carriage  146 . Thus, separate rails are eliminated by the use of gear racks  204 ,  210  for lateral support. The pinion gears  202 ,  208  intersect the keyways  212 ,  214  for access to the gear racks  204 ,  210 . Additionally, a pair of roller bearings  216  are displaced within each keyway  212 ,  214  to engage a forward bearing surface of each gear rack  204 ,  210 . Thus, loading imparted to the carriage  146 , such as a reaction force during the massage operation, or the weight from the body portion of the user, is distributed from the carriage  146  to the lower housing portion  142  through the roller bearings  216 . Further, friction is reduced between the carriage  146  and the lower housing portion  142  by the roller bearings  216 .  
      Similar to the prior embodiment, a coiled power cord  218  is provided in the backrest region  140  as illustrated in  FIG. 7 . The power cord  218  powers the motor  178 . A longitudinal bar  220  is mounted within the lower housing portion  142  for extension and retraction of the coiled power cord  218  along the bar  220 .  
      The backrest region  140  also includes a series of limit switches  222   a - 222   f  for providing signals for indicating the orientation of the carriage  146 . The signals are processed by a controller of a circuit board  224  within the backrest region  140  and/or a circuit board in the associated remote  28  ( FIG. 1 ). As discussed above with reference to the prior embodiment, the signals from the limit switches  222   a - 222   f  are utilized to reverse the direction of the motor  178  and consequently reverse the direction of the carriage  146 . The limit switches  222   a - 222   f  provide various ranges of massage so that the user can select a desired target range, such as upper back, mid back, lower back, or combinations of these regions, including entire length of the back.  
      The controller may also cooperate with the massage assembly  144  to return the carriage  146  to a parked position when not in use. For example, upon the user selecting the termination of a massage operation through the remote  28 , the controller may drive the motor  178  in a direction for translating the carriage  146  to a lowermost position in the backrest region  140 , which is indicated by the lowermost limit switch  222   f . Thus, the carriage  146  may rest against a bumper  226  when not in operation so that the load of the carriage  146  is supported upon the bumper  226  instead of being supported by the transmission of the carriage  146 . This parked position may also serve as a start position for massage programs such that the programs of the controller may have a consistent start position for various massage programs.  
      While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.