Telescopic support for armrest

Abstract

A telescopic support is provided for an armrest of a chair. The telescopic support includes a lower tube, an upper tube and a helical spring. The lower tube is installed on the chair. The upper tube telescopically receives the lower tube and supports the armrest. The helical spring is axially positioned in the upper tube and compressed between the upper tube and the lower tube for automatically and smoothly lifting the upper tube from the lower tube.

1 . A telescopic support for an armrest of a chair, the telescopic support comprising a lower tube ( 70 ;  60 B), an upper tube ( 10 ;  10 B) for telescopically receiving the lower tube and supporting the armrest and a helical spring ( 40 ) axially positioned in the upper tube and compressed between the upper tube and the lower tube for automatic and smooth lifting of the upper tube from the lower tube.  
   
   
       2 . The telescopic support according to  claim 1  comprising a guide ( 20 ) axially inserted in the upper tube for guiding the helical spring.  
   
   
       3 . The telescopic support according to  claim 2  wherein the guide comprises a rod inserted through the helical spring.  
   
   
       4 . The telescopic support according to  claim 3  wherein the rod comprises a groove ( 23 ) and at least one aperture ( 25 ) in communication with the groove, wherein the telescopic support comprises: 
 a retainer ( 60 ) fit in the lower tube, the retainer comprising a channel ( 66 ) for receiving the rod and at least one series of recesses ( 61 ) in communication with the channel;    at least one ball ( 50 ) positioned in the aperture of the rod for insertion into selected one of the recesses of the retainer so as to retain the guide and the upper tube in position relative to the retainer and the lower tube; and    a controller ( 30 ) movable in the groove of the rod between a first position for pushing the ball into selected one of the recesses of the retainer and a second position for allowing the movement of the ball from the recesses.    
   
   
       5 . The telescopic support according to  claim 4  comprising a handle ( 80 ) connected to the controller ( 30 ).  
   
   
       6 . The telescopic support according to  claim 5  wherein the upper tube comprises an opening ( 13 ) through which the handle is exposed from the upper tube.  
   
   
       7 . The telescopic support according to  claim 4  wherein the helical spring is compressed between an end of the retainer and two fasteners ( 22 ) secured to the rod.  
   
   
       8 . The telescopic support according to  claim 4  wherein the controller comprises a wedge ( 35 ) for pushing the ball.  
   
   
       9 . The telescopic support according to  claim 4  comprising a spring ( 37 ) for connecting the controller to the rod, thus tending to push the controller to the first section from the second section.  
   
   
       10 . The telescopic support according to  claim 4  wherein the upper tube comprises an enlarged upper portion ( 11 ), wherein the guide comprises a platform ( 28 ) formed on the rod and positioned in the enlarged upper portion of the upper tube.  
   
   
       11 . The telescopic support according to  claim 1  comprising a platform ( 11 B) installed on the upper tube and a cap ( 61 B) installed on the lower tube, wherein the helical spring is compressed between the cap and the platform.  
   
   
       12 . The telescopic support according to  claim 11  wherein the helical spring comprises a lower end fit on a portion of the cap so that the helical spring is positioned.  
   
   
       13 . The telescopic support according to  claim 12  wherein the upper tube comprises two lateral apertures ( 13 B) defined therein, wherein the lower tube comprises two opposite series of continuous apertures ( 62 ) defined therein, wherein the telescopic support comprises a controller ( 80 B) with a latch ( 813 B) movably inserted in the lateral apertures of the upper tube and the two series of continuous apertures of the lower tube, wherein the latch ( 813 B) comprises two reduced sections ( 814 B) movable in the two series of continuous apertures of the lower tube for allowing the movement of the latch in and along the two series of continuous apertures of the lower tube.  
   
   
       14 . The telescopic support according to  claim 13  wherein the controller comprises a button ( 81 B) connected to an end of the latch, a washer ( 832 B) and a fastener ( 831 B) secured to an opposite end of the latch through the washer so that the button and the washer retain the latch in the upper tube.  
   
   
       15 . The telescopic support according to  claim 14  wherein the controller comprises a spring ( 82 B) compressed between the button and the upper tube for moving the reduced sections of the latch from the two series of continuous apertures of the lower tube.  
   
   
       16 . The telescopic support according to  claim 14  wherein the latch comprises a ridge ( 815 B) formed thereon, wherein the upper tube comprises a cutout ( 15 B) defined in the edge of each of the lateral apertures for receiving the ridge of the latch so that the latch cannot be rotated in the upper tube.  
   
   
       17 . The telescopic support according to  claim 14  wherein the upper tube comprises a lip ( 14 B) around one of the lateral apertures for protecting the button.  
   
   
       18 . The telescopic support according to  claim 14  wherein the upper tube comprises a lip ( 16 B) around one of the lateral apertures for protecting the washer and the fastener.  
   
   
       19 . The telescopic support according to  claim 18  wherein the controller comprises a cover ( 84 B) installed on the lip for covering the washer and the fastener.  
   
   
       20 . The telescopic support according to  claim 19  wherein the cover comprises a ridge ( 842 B) formed thereon, wherein the lip defines, on an internal side, a groove ( 161 B) for receiving the ridge of the cover.