Patent Publication Number: US-2006016648-A1

Title: Shock absorber of a seat of a wheelchair

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a shock absorber of a seat of a wheelchair, which can reduce violent shaking of the seat effectively for the wheelchair to be comfortable to ride on.  
      2. Brief Description of the Prior Art  
      Conventional wheelchairs for people to ride on are usually only equipped with shock absorbers between the wheels and the frame, but are not equipped with shock absorbers for the seats. Therefore, violent shaking of one such conventional wheelchair can&#39;t be effectively reduced, and a person ridding on the wheelchair will still feel uncomfortable when the wheelchair is shaking violently.  
     SUMMARY OF THE INVENTION  
      It is a main object of the present invention to provide a shock absorber of a seat of a wheelchair such that violent shaking of the seat can be effectively reduced.  
      The shock absorber of the present invention includes an outer tube secured on an upper side of a frame of the wheelchair, an inner tube secured on a bottom of the seat and movably passed into the outer tube, and a spring-loaded shock absorbing mechanism. The outer tube is formed with a pair of opposing radial holes on an upper end portion. The inner tube is formed with two opposing lengthwise extending slots, and is prevented from separating from the outer tube with help of a pin, which is passed through the radial holes as well as the slots; the shock absorbing mechanism is held in the outer tube and connected to the outer tube, and a lower end of the inner tube at lower and upper ends thereof respectively. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The present invention will be better understood by referring to the accompanying drawings, wherein:  
       FIG. 1  is a perspective view of the wheelchair according to the present invention,  
       FIG. 2  is an exploded perspective view of the present invention,  
       FIG. 3  is a vertical sectional view of the present invention, and  
       FIG. 4  is a vertical sectional view of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Referring to  FIGS. 1 and 2 , a preferred embodiment of a shock absorber of a seat  3  of a wheelchair includes an outer tube  6 , a shock absorbing mechanism  8 , and an inner tube  7 .  
      The outer tube  6  is formed with several pairs of opposing radial through holes  61  along an upper end portion, and several pairs of opposing radial through holes  62  along a lower end portion thereof; the distance between every two adjacent upper holes  61  is the same as the distance between every two adjacent lower holes  62 . A pin  64  is tightly passed through a selected pair of lower through holes  62 .  
      The inner tube  7  is formed with two lengthwise extending slots  71 , which are right faced with each other. A strengthening element  72  is tightly fitted in the slots  71 , which has a through hole having the same shape as the slots  71 , and a gap  721  at a bottom side thereof. The inner tube  7  is up and down movably passed into the outer tube  6 , and a pin  63  is passed through the through hole of the strengthening element  72  and a selected pair of upper through holes  61 ; thus, the inner tube  7  can&#39;t separate from the outer tube  6 , and it can only be displaced relative to the outer tube  6  within a certain range. And, the pin  64  at the lower portion of the outer tube  6  will stop the inner tube  7  to prevent the same from moving further down.  
      The shock absorbing mechanism  8  includes an elastic element  81 , which is passed through the gap  721  of the strengthening element  72 , and hooked over the pin  63  at a first end  811  thereof. In addition, a locating pin  73  is secured on a lower end of the inner tube  7 , and the elastic element  81  is hooked over the locating pin  73  at a second end  812  thereof.  
      Thus, when the seat  3  of the wheelchair moves upwards and downwards during shaking of the wheelchair, the elastic element  81  will counteract movement of the seat  3 . Consequently, the wheelchair will be more comfortable to ride on.  
      From the above description, it can be easily understood that the shock absorber of the present invention can reduce violent shaking of the seat effectively when one is ridding on the wheelchair.