Patent Publication Number: US-6336680-B1

Title: Height-adjustment mechanism for armrest

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a height-adjusting mechanism for armrest that enables easily adjustment of an armrest to a desired height relative to a seat of an armchair simply by pulling upward a handle and moving the armrest to a desired position and then releasing the handle. 
     There are different designs for armrests of armchairs. There are also different mechanisms for adjusting armrests to different heights and/or different open angles, so that users sit on the armchairs more comfortably and the armchairs are more valuable. The mechanisms for adjusting armrests are kept improved mostly in their spatial configurations, number of parts, and/or operating manners, so as to create armchairs having different structures, improved functions or reduced manufacturing cost to increase their competition ability in the markets. 
     SUMMARY OF THE INVENTION 
     A primary object of the present invention is to provide a height-adjusting mechanism for armrest. The mechanism mainly includes a slider movably mounted in a slide way of a sleeve connected at a lower end to a seat of an armchair. An armrest is connected to a top of the slider. A retaining block horizontally extends through a transverse hole on the slider and into one of many vertically spaced locating holes on the slide way to hold the slider to a certain height relative to the sleeve. A long plate having a top handle is attached to one side of the slider and could be pulled upward and elastically return to an original position when being released. When the long plate is a pulled upward, it drives the retaining block to disengage from the locating hole and allows the slider to freely move up and down. And, when the long plate is released, the retaining block is driven to engage into another locating hole to hold the slider to a new height. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein 
     FIG. 1 is an assembled perspective view of a height-adjusting mechanism for armrest according to a first embodiment of the present invention; 
     FIG. 2 is an exploded perspective view of the height-adjusting mechanism for armrest of FIG. 1; 
     FIG. 3 is a sectioned side view of the height-adjusting mechanism for armrest of FIG. 2; 
     FIG. 4 shows the height-adjusting mechanism for armrest of FIG. 3 is adjusted to a higher position; 
     FIG. 5 is an assembled perspective view of a height-adjusting mechanism for armrest according to a second embodiment of the present invention; and 
     FIG. 6 a sectioned side view of the height-adjusting mechanism for armrest of FIG.  5 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Please refer to FIGS. 1 through 4 in which a height-adjusting mechanism for armrest according to a first embodiment of the present invention is shown. 
     The height-adjusting mechanism for armrest includes a sleeve  10 , a lower end of which is screwed to a bracket  11  that is then screwed to a seat of an armchair (not shown) to form an arm support. A tubular member  20  is mounted in the sleeve  10  with an upper end seated on a top of the sleeve  10 . The tubular member  20  is provided with an internal slide way  21 , an inner side of which is provided with a vertical row of equally spaced locating holes  22 . A wall of the tubular member  20  opposite to the slide way  21  is cut away to form a vertically extended an access window  23 , via which related components or parts are conveniently mounted in the tubular member  20 . 
     A slider  30  is vertically movably received in the slide way  21 . The slider  30  includes an arm bracket  31  additionally connected to or integrally formed at a top thereof for an armrest (not shown) to connect to the arm bracket  31 , and a vertical trough  34  formed at an outer side of the slider  30 . A fixing hole  32  and a transverse through hole  33  are separately provided at predetermined positions in the trough  34 . An exterior cover  35  may be connected to the slider  30  to create an integral appearance of the height-adjusting mechanism. 
     A long plate  40  is located at the outer side of the slider  30  in the trough  34  and has an outward bent upper end to provide a handle  41  that is accessible from outside of the outer cover  35 , a horizontal lug  42  provided below the handle  41  for a spring  43  to connect at an upper end thereto, a vertical long slot  44  formed below the lug  42 , and an outward protruded portion  45  formed below the long slot  44 . 
     A fixing plate  50  and an elongate guiding plate  60  are sequentially attached to an outer side of the long plate  40 , so that the fixing plate  50  and the guiding plate  60  and the long plate  40  are together fixed onto the slider  30  with the long slot  44  corresponding to the fixing hole  32 . 
     The long plate  40  is vertically movable in the trough  34  within a range defined by upper and lower ends of the long slot  44 . The fixing plate  50  has an outward bent lug  51  at its top to connect to a lower end of the spring  43 , such that the long plate  40  automatically returns to a lower position under an elastic force of the spring  43  when the long plate  40  is upward pulled and released again. 
     The guiding plate  60  is formed at a predetermined position with an inward protruded portion  61  to face toward the outward protruded portion  45  of the long plate  40 . The guiding plate  60  is connected to a transverse retaining block  70  by engaging a lower end of the guiding plate  60  with a slot  71  at an outer end of the retaining block  70 . 
     The retaining block  70  is adapted to extend an inner end  72  through the transverse slot  33  on the slider  30  and extend into one of the locating holes  22  on the slide way  21 . The inner end  72  of the retaining block  70  has a configuration corresponding to that of the locating hole  22  and preferably includes a right-angled lower end surface and a beveled upper end surface. This configuration allows the retaining block  70  to move only upward to pass over a locating hole  22  but not downward to disengage from the locating hole  22 . That is, the retaining block  70  works like a ratchet to allow a one-way adjustment of its position. 
     When the handle  41  is not upward pulled, as shown in FIG. 3, the outward protruded portion  45  of the long plate  40  is located below the inward protruded portion  61  of the guiding plate  60 , the guiding plate  60  has a lower end in a vertically downward extended position, and the retaining block  70  is in engagement with one of the locating holes  22 . Since the retaining block  70  is extended through the transverse slot  33  on the slider  30 , the slider  30  is held by the retaining block  70  at a fixed height. 
     There are several different ways to adjust the height of an armrest mounted to the arm bracket  31  relative to a seat of the armchair: 
     (1) To adjust the armrest to a higher position, a user may directly pulls the armrest upward to move the slider  30  upward. With an inherent elasticity of the long plate  60  and the one-way adjustment function of the retaining block  70 , the retaining block  70  is brought by the upward pulled long plate  40  to upward pass over each upper locating hole  22  until the armrest reaches a desired height. At this point, the retaining block  70  is located in a new locating hole  22  to complete the height adjustment of the armrest. 
     (2) To adjust the armrest to a lower position, a user may first pull the handle  41  upward, as shown in FIG. 4, so that the long plate  40  moves upward and the outward protruded portion  45  is brought to push against the inward protruded portion  61  of the guiding plate  60 , causing the lower end of the guiding plate  60  to shift outward to leave the original downward vertical position and the retaining block  70  to disengage from the locating hole  22 . At this point, the slider  30  in the slide way  21  is allowed to freely move downward until the armrest reaches a desired height. The handle  41  is then released, and the retaining block  70  is automatically pulled by the elasticity of the guiding plate  60  to engage into a new locating hole  22  at a lower position to complete the adjustment of the armrest. 
     (3) To adjust the armrest to either a higher or a lower position, a user may pull the handle  41  upward, as shown in FIG. 4, so that the slider  30  is freely slidable up and down in the slide way  21 . At this point, the user may move the armrest upward or downward to a desired position and then releases the handle  41 . 
     (4) Alternatively, a user may first pull the handle  41  upward to free the slider  30 , and then pushes the armrest to a lowest position before releases the handle  41 . Thereafter, the armrest may be pulled upward to a desired height in the manner as described in the above paragraph (1). 
     FIGS. 5 and 6 are assembled perspective and sectioned side views, respectively, of a height-adjusting mechanism for armrest according to a second embodiment of the present invention. The second embodiment and the first embodiment are identical in their functions and operations. 
     The height-adjusting mechanism for armrest according to the second embodiment of the present invention mainly includes a sleeve A 10 , a lower end of which is screwed to a bracket A 11  that is then screwed to a seat of an armchair (not shown) to form an arm support. A tubular member A 20  is mounted in the sleeve A 10  with an upper end seated on a top of the sleeve A 10 . 
     The tubular member A 20  is provided with an internal slide way A 21 , an inner side of which is provided with a vertical row of equally spaced locating holes A 22 . A wall of the tubular member A 20  opposite to the slide way A 21  is cut away to form a vertically extended an access window A 23 , via which related components or parts are conveniently mounted in the tubular member A 20 . 
     A slider A 30  is vertically movably received in the slide way A 21 . The slider A 30  includes an arm bracket A 31  additionally connected to or integrally formed at a top thereof for an armrest (not shown) to connect to the arm bracket A 31 , and a vertical trough A 34  formed at an outer side of the slider A 30 . A fixing hole A 32  and a transverse through hole A 33  are separately provided at predetermined positions in the trough A 34 . An exterior cover (not shown) may be connected to the slider A 30  to create an integral appearance of the height-adjusting mechanism. 
     A long plate A 40  is located at the outer side of the slider A 30  and has an outward bent upper end to provide handle A 41  that is accessible from outside of the outer cover, a horizontal lug A 42  provided below the handle A 41  for a spring A 43  to connect at an upper end thereto, and a vertical long slot A 44  formed below the lug A 42 . A lower end of the long plate A 40  is extended through a retaining block A 70  and then formed into an outward protruded portion A 45 . 
     A fixing plate A 50  is located at an outer side of the long plate A 40  and is screwed to the slider A 30  with a screw extended through the long slot A 44  of the long plate A 40  and into the fixing hole A 32  of the slider A 30 , such that the long plate A 40  is vertically movable in the trough A 34  within a range defined by upper and lower ends of the long slot A 44 . The fixing plate A 50  has an outward bent lug A 51  at its top to connect to a lower end of the spring A 43 , such that the long plate A 40  automatically returns to a lower position under an elastic force of the spring A 43  when the long plate A 40  is upward pulled and released again. 
     A guiding plate A 60  having predetermined length and elasticity is screwed at a lower end A 61  to a lower end of the slider A 30 , such that an upper end A 62  of the guiding plate A 60  elastically presses against the retaining block A 70  inward. 
     The retaining block A 70  is a U-shaped block defining an internal space A 71  through which the lower end of the long plate A 40  extends. Two inner ends A 72  of the U-shaped retaining block A 70  extend through the transverse slot A 33  on the slider A 30  and extend into one of the locating holes A 22  on the slide way A 21 . Each inner end A 72  of the retaining block A 70  has a configuration corresponding to that of the locating hole A 22  and preferably includes a right-angled lower end surface and a beveled upper end surface. This configuration allows the retaining block A 70  to move only upward to pass over a locating hole A 22  but not downward to disengage from the locating hole A 22 . That is, the retaining block A 70  works like a ratchet to allow a one-way adjustment of its position. When the handle A 41  is upward pulled, the outward protruded portion A 45  of the long plate A 40  is moved upward into the internal space A 71  of the U-shaped retaining block A 70  to directly push the retaining block A 70  outward and disengage the two inner ends A 72  of the retaining block A 70  from the locating hole A 22 , allowing the slider A 30  to slide up and down to a desired height. When the handle A 41  is released again, the retaining block A 70  is elastically pushed by the guiding plate A 60  inward to automatically extend the two inner ends A 72  into a new locating hole A 22  to complete the adjustment of the armrest in height. The armrest connected to the height-adjusting mechanism of the second embodiment could be adjusted to a desired height through operating procedures completely the same as that described in the first embodiment.