Patent Publication Number: US-2007120408-A1

Title: Backrest and armrest synchronous adjustment device for a massage chair

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to an adjustment device for a massage chair, and more particularly to a backrest and armrest synchronous adjustment device for a massage chair.  
      2. Description of the Prior Art  
      Most of the backrests of the existing massage chairs are adjustable and can be fixed at different angles, and the tilt angle of the backrest is usually controlled by an advanced electronic control system. However, these conventional massage chairs still have the following shortcomings that need to be improved:  
      Firstly, the armrest is inflexible and cannot be adjusted in response to the angle adjustment of the backrest, so that the user feels uncomfortable since his arms cannot be laid comfortably on the armrest if the backrest is reclined back.  
      Secondly, since different users use the massage chair, the users whose arms are relatively short, like the children and old people, will feel particularly uncomfortable due to their arms are too short to be rest on the armrest after the backrest is reclined back.  
      The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.  
     SUMMARY OF THE INVENTION  
      The primary objective of the present invention is to provide an armrest and backrest synchronous adjustment device for a massage chair comprising a base, a backrest, at least two armrests and two rail members. The base is formed with a space. The backrest is pivoted on the base and located correspondingly to the space of the base. The armrests are pivoted to the base, and lower end of each of the armrests is located correspondingly to the space of the base. The rail members are mounted at the lower end of the armrests or the backrest and located in the space of the base, on each of the rail members is formed a slot that is used to rotate the armrests when the backrest is adjusted.  
      The present invention will become more obvious from the following description when taken in connection with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiments in accordance with the present invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a front view of an armrest and backrest synchronous adjustment device for a massage chair in accordance with the present invention;  
       FIG. 2  is a side view of the armrest and backrest synchronous adjustment device for a massage chair in accordance with the present invention;  
       FIG. 3  is an exploded view of an armrest in accordance with the present invention;  
       FIG. 4  is an assembly view of the armrest in accordance with the present invention;  
       FIG. 5  is an operational view of showing the armrest and backrest synchronous adjustment device for a massage chair in accordance with the present invention;  
       FIG. 6  is another operational view of showing the armrest and backrest synchronous adjustment device for a massage chair in accordance with the present invention;  
       FIG. 7  is an exploded view of a slide track structure of the armrest in accordance with the present invention; and  
       FIG. 8  shows another slide track structure of the armrest in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Referring to  FIGS. 1-4 , an armrest and backrest synchronous adjustment device for a massage chair in accordance with the present invention is mounted on a massage chair  10  and comprises: a base  20 , a backrest  30 , two armrests  40  and two rail members  50 .  
      The base  20  is a rack assembly fixed to the bottom of the massage chair  10  and is set firmly on the ground. The base  20  includes a narrow first rack  21  and a wide second rack  22 , the first rack  21  is located within the second rack  22 , and between the first and second racks  21  and  22  is formed a space A.  
      The backrest  30  is pivoted to the first rack  21  of the base  20  and is located correspondingly to the space A, and at both sides of the lower end of the backrest  30  are coaxially arranged two pivotal shafts  31  on each of which being mounted an extending rack  312  and a retainer  311 .  
      The armrests  40  each includes a support portion  41 , a pivot  42  and two positioning cylinders  43  sequentially mounted on an armrest rack  45  in a top down manner. The armrests  40  are pivoted on the second rack  22  by the pivot  42  and the slide sleeve  44 , and the positioning cylinders  43  below the armrests  40  are located correspondingly to the space A of the base  20 . Beneath the support portion  41  are sequentially arranged a positioning board  401 , a partition board  402  and a base board  403  (as shown in  FIG. 7 ), in the positioning board  401  and the partition board  402  are formed a plurality of slide tracks  411  (which are in the form of elongated holes in this embodiment) that are arranged in a crisscross pattern. On the partition board  402  and on the base board  403  are formed a plurality of protrusions  412  to be moveably inserted in the slide tracks  411 . The support portion  41  is positioned on the armrest  45  via the slide tracks  411 , and the user can use the crisscrossed slide tracks  411  to make the positioning board  401 , the partition board  402  and the base board  403  move relative to one another, so that the support portion  41  can be adjusted to different positions to support the user&#39;s arm.  
      The rail members  50  are in the form of a board, each of the rail members  50  is mounted on the two positioning cylinders  43  below the armrest  40  and is located in the space A of the base  20 . In each of the rail members  50  is formed a slot  51  for insertion of the pivotal shafts  31 , and then the pivotal shafts  31  are moveably confined in the slot  51  of the rail members  50  by the retainers  311 .  
      For a better understanding of the present invention, reference should be made to  FIGS. 4-6 , the backrest  30  is pivoted to the first rack  21  of the base  20 , so that the backrest  30  can be adjusted automatically or manually to different angles according to the user&#39;s needs. Furthermore, at both sides of the lower end of the backrest  30  are coaxially arranged the pivotal shafts  31  on each of which being mounted an extending rack  312 , the pivotal shafts  31  are moveably confined in the slots  51  of the rail members  50 . Plus the armrests  40  are pivoted to the second rack  22  by the pivot  42  and the slide sleeve  44 .  
      By such arrangements, the rail members  50  will rotate within the space A of the base  20  synchronously when the tilt angle of the backrest  30  is adjusted. Due to the rail members  50  are mounted on the two positioning cylinders  43  below the armrest  40 , when the rails members  50  are driven by the pivotal shafts  31  to rotate within the space A, the rails members  50  will synchronously rotate the armrest  40 . Meanwhile, the support portion  41  of the armrest  40  will be tilted towards the second rack  22 , and with the help of the crisscrossed slide tracks  411 , the support portion  41  can be adjusted to different positions in response to the tilt angle adjustment of the backrest  30 , to support the user&#39;s arm.  
      It will be noted that another function of the present invention is that the slot  51  can be used to adjust the tilt angle of the armrest  40  due to the slot  51  is a slant slot. Furthermore, the slot  51  also can be formed in different curvatures or tilt angles, so as to change the tilt angle of the armrest  40 .  
      Referring to  FIG. 8 , slide tracks of the armrest in accordance with another embodiment of the present invention are shown, wherein the positioning board  401 , the partition board  402  and the base board  403  are also located below the support portion (not shown) of the armrest  40 , and the slide tracks  411  (which are in the form of a slide rod) are arranged at the upper and lower sides of the partition board  402 . In the positioning board  401  and the base board  403  are formed a plurality of holes  413  for insertion of the slide tracks  411 . The support portion  41  is positioned on the armrest  45  via the slide tracks  411 , and the user can use the crisscrossed slide tracks  411  to make the positioning board  401 , the partition board  402  and the base board  403  move relative to one another, so that the support portion  41  can be adjusted to different positions to support the user&#39;s arm.  
      While we have shown and described various embodiments in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.