Patent Publication Number: US-2009230750-A1

Title: Infinitely adjustable armrest for seat

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/036,402 filed Mar. 13, 2008. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to an armrest for a seat, and more specifically an armrest that is infinitely adjustable over a defined range of motion. 
     BACKGROUND OF THE INVENTION 
     In the field of seating devices, it is often desirable to have seats with adjustable armrests. This permits the armrest to maintain a level orientation with an associated floor while the back of the seating device is adjusted to alter the inclination thereof. The armrest can also be adjusted to provide the desired orientation for comfort for the differing sizes and shapes of individuals using the seat. Often, seat armrests are limited to a down position or an up position, with no variable adjustments between the two positions. Other devices have been developed which allow adjustment in a limited range, or at limited and specific positions. As an example, ratchet type mechanisms are often employed in armrests to provide adjustability. The ratcheting mechanism, however, limits the adjustments of the arm rest to specific positions due to the operation of the mechanism. 
     It would be highly advantageous, therefore, to remedy the foregoing and other deficiencies inherent in the prior art. 
     SUMMARY OF THE INVENTION 
     Briefly, to achieve the desired objects and advantages of the instant invention apparatus is provided mounting an armrest to a seatback with infinite adjustments. It will be understood that the term “infinite adjustment” refers to the adjustability of the armrest being continuously moveable and lockable anywhere between the limits. The apparatus includes an inner tube affixed to the seatback and an outer tube affixed to the armrest and coaxially mounted over the inner tube so as to rotatably nest the outer tube over the inner tube. A substrate is affixed to the outer tube, and a guide is formed on the substrate. A slave link is pivotally attached to the inner tube. A lock link is pivotally attached to the slave link so as to be positioned in the guide in the substrate and is movable relative to the substrate. A lock mechanism is movably mounted on the substrate. The lock link is slideably engaged with the lock mechanism for relative movement between the lock link and the lock mechanism, the lock mechanism being movable between a locked position in which the lock mechanism frictionally engages the lock link and an unlocked position in which the lock link is free to slide relative to the lock mechanism. An adjustment lever is positioned to temporarily move the lock mechanism from the locked position into the unlocked position and a spring is coupled between the substrate and the lock mechanism for biasing the lock mechanism into the locked position to hold the lock link and the armrest in a selected position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Specific objects and advantages of the invention will become readily apparent to those skilled in the art from the following detailed description of a preferred embodiment thereof, taken in conjunction with the drawings in which: 
         FIG. 1  is a side elevational view of an infinitely adjustable armrest in accordance with an embodiment of the present invention; 
         FIG. 2  is a side elevational view of a substrate portion of the armrest of  FIG. 1 ; 
         FIG. 3  is an isometric view of the substrate portion of the armrest of  FIG. 3 ; 
         FIG. 4  is an isometric view of the view of an outer tube portion of the armrest of  FIG. 1 ; 
         FIG. 5  is an isometric view of an inner tube portion of the armrest of  FIG. 1 ; 
         FIG. 6  is a sectional side view of the inner tube portion of the armrest of  FIG. 5 ; 
         FIG. 7  is an end view of the inner tube portion of the armrest of  FIG. 5 ; 
         FIG. 8  is an isometric view of a lock portion of the armrest of  FIG. 1 ; 
         FIG. 9  is an exploded view of the infinitely adjustable armrest of  FIG. 1 ; 
         FIG. 10  is a side elevational view of the infinitely adjustable armrest in an upright or vertical position and in a lower or horizontal position; 
         FIG. 11  is an exploded view in perspective of another embodiment of infinitely adjustable armrest in accordance with the present invention; 
         FIG. 12  is a view in perspective of the infinitely adjustable armrest of  FIG. 11  assembled, portions thereof removed to illustrate inner components; 
         FIG. 13  is a view in perspective of the infinitely adjustable armrest of  FIG. 11  assembled within an enclosing housing; and 
         FIG. 14  is a top plan view of the armrest assembled within an enclosing housing and attached to a portion of a seat back. 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     Referring to  FIG. 1 , an infinitely adjustable armrest  10 , in accordance with the present invention, is illustrated. Armrest  10  includes a substrate  12 , an outer tube  14 , an inner tube  16 , a slave link  18 , a lock link  20 , a lock mechanism  22 , and an extension spring  24  (biasing member). It will be understood by those skilled in the art that armrest  10  will generally be associated with a seat such as those used in airplanes, busses, trucks, trains and other vehicles as desired, but that armrest  10  can be used with any seat or other device to which a movable armrest might be attached, including desk chairs and the like. It will also be understood that certain arm supporting structure and padding will generally be included in the armrest with the mechanism illustrated but this structure is not shown in this embodiment, since it is not a part of this invention and to better illustrate the operating mechanism of armrest  10 . 
     Referring additionally to  FIGS. 2 and 3 , substrate  12  is illustrated in more detail. Substrate  12  includes flanges  30  formed perpendicular to the main body of substrate  12  along a lower edge (upper edge in  FIGS. 3 and 4 ) and breaks in the main body of substrate  12  formed into flanges  32  that are parallel with and spaced from flanges  30 . Together, flanges  30  and  32  form a track (or guide) in which lock link  20  is positioned and movable in a reciprocating manner. Another break in the main body of substrate  12  forms a vertical flange  34  that is positioned to have one end of extension spring  24  attached thereto. An arcuate slot  36  is formed in the main body of substrate  12  adjacent one end  37 . For purposes of this disclosure the one end  37  will be referred to as the rear end and the opposite end, designated  38 , will be referred to as the front or forward end. Arcuate slot  36  is substantially circular and extends for approximately 270° and may extend a few degrees (e.g. up to 5°) more or less. 
     Referring additionally to  FIG. 4 , outer tube  14  is illustrated in more detail. Outer tube  14  is a generally hollow cylinder with a rectangular notch  39  cut out of the periphery at one end. Notch  39  extends approximately 90° and may extend a few degrees (e.g. up to 5°) more or less around the periphery. Further, tube  14  is designed and constructed to be fixedly engaged in slot  36  of substrate  12  so as to form an arcuate slot between substrate  12  and tube  14  and rotate with substrate  12  as armrest  10  is pivoted. In a preferred embodiment, substrate  12  and most of the other components can be formed of metal, such as sheet metal, sheet steel, or a sufficiently rigid and rugged plastic so that tube  14  could be fixed in place for example by welding or some compatible adhesive. 
     Referring additionally to  FIGS. 5 ,  6 , and  7 , inner tube  16  is illustrated in more detail. Inner tube  16  is a generally hollow cylinder with one end  40  closed to form a generally circular cylindrical cup-shape. A mounting hole  42  is formed in end  40 . Inner tube  16  is designed and formed to be fixedly attached to a seat back or the like and to be rotatably received within outer tube  14 . Thus, as will be better understood from the following description, armrest  10  is substantially supported on a seat back or the like by outer tube  14  rotatably nested over inner tube  16 . It will of course be understood that inner tube  16  could be a short section, as shown and be attached to, for example, a side of a seat back (not shown) or could extend through the seat back and out the other side to provide a mount for a second infinitely movable armrest  10 , if desired. 
     With momentary reference to  FIG. 9 , slave link  18  and lock link  20  are clearly illustrated. Slave link  18  is an elongated link or strip of rigid material formed with mounting holes  46  and  48  adjacent opposite ends. Lock link  20  is an elongated link or strip of rigid material formed with a mounting hole  50  and  48  adjacent one end and a longitudinally extending guide slot  52  extending from adjacent the opposite end toward the one end. 
     Referring additionally to  FIG. 8 , lock mechanism  22  is illustrated in more detail. Lock mechanism  22  includes multiple portions in a single element in this embodiment. As will be described in a subsequent embodiment, the various portions can be supplied separately. Lock mechanism  22  is formed from an elongated link or strip of rigid material bent approximately 360° at one end to form a hook  60 . The strip of material is bent approximately 98° (generally L-shaped), give or take a few degrees, adjacent the opposite end to form an adjustment lever  62 , as will be understood from the following description. A longitudinally extending locking slot  64  is formed through the main body (locking element) of lock mechanism  22 . An opening  66  is formed in the main body of lock mechanism  22  and positioned to receive an opposite end of extension spring  24 . 
     The relative positions of the various components described above are illustrated in  FIG. 9 . Referring to  FIGS. 1 and 9 , the assembly of the various components described above can be seen. A pivot pin is fixed concurrently through mounting hole  46  of slave link  18  and mounting hole  42  in inner tube  16  to pivotally attach slave link  18  to inner tube  16 . Inner tube  16  is then nestingly or coaxially positioned in outer tube  14  with slave link  18  positioned in peripheral notch  39  and outer tube  14  is fixed in slot  36  of substrate  12 . As described above, inner tube  16  is affixed to the back rest of a seat or the like on which armrest  10  is to be an armrest. 
     A mounting or pivot pin  70  is affixed to substrate  12  adjacent the upper edge so as to extend generally perpendicular to the surface parallel to and between flanges  32 . Hook  60  of lock mechanism  22  is positioned over pivot pin  70  with lock mechanism  22  hanging downwardly from adjacent the upper edge. The length of the main body of lock mechanism  22  is such that adjustment lever  62  is positioned below the lower surface of substrate  12  (as illustrated in  FIG. 1 ). Lock link  20  is inserted through slot  64  in lock mechanism  22  so as to be slideably engaged therein. A pivot pin is fixed concurrently through mounting hole  48  of slave link  18  and mounting hole  50  in lock link  20  to pivotally attach lock link  20  to slave link  18 . In this fashion lock link  20  is slideably engaged in the track formed or defined by flanges  30  and  32 . 
     Also a stop pin  72  is affixed to substrate  12  and spaced above flange  30  so as to extend generally perpendicular to the surface parallel to and spaced above the flanges  30  adjacent forward end  38  of substrate  12 . Stop pin  72  is positioned to extend through slot  52  in lock link  20 . Extension spring  24 , which is a tension spring, is connected between vertical flange  34  and opening  66  in lock mechanism  22 . Spring  24  biases lock mechanism  22  rearwardly (toward rear end  37 ) which is the locked position of lock mechanism  22 . In the locked position lock link  20  is frictionally engaged with the top and bottom edges of slot  64  in lock mechanism  22  and lock link  20  cannot move further toward rear end  37  of substrate  12 . However, lock link  20  will move freely toward the front end  38  of substrate  12  and, thus, armrest  10  can be easily moved from any position, such as the horizontal position illustrated in  FIG. 10  toward the vertical position. Once moved toward the vertical position, armrest  10  is prevented from moving back toward any lowered position. Further, armrest  10  can be positioned at any of an infinite number of positions between the upper and lower positions illustrated in  FIG. 10  by simply raising adjustment lever  62  (i.e. rotating adjustment lever  62  counterclockwise in  FIG. 10 ), moving armrest  10  to a desired position upwardly or downwardly, and releasing adjustment lever  62  to lock armrest  10  and prevent downward movement from the selected position. 
     Turning now to  FIG. 11 , another embodiment of an infinitely adjustable armrest, designated  100  (seen in entirety in  FIGS. 13 and 14 ) is illustrated. Armrest  100  includes a substrate  102 , an outer tube  104 , an inner tube  106 , a slave link  108 , a lock link  120 , and a lock mechanism  122  including a manually operated adjustment lever  124 . 
     In this embodiment substrate  102  is formed in the shape of an elongated channel with a generally U-shaped cross-section for additional strength. Substrate  102  has a channel bottom  130  with a first side  132  and an opposed side  134  generally parallel and spaced from each other. Four pins,  135 ,  136 ,  137 , and  138 , extended across the channel between sides  132  and  134  to form a guide or track in which lock link  120  is positioned and movable in a reciprocating manner. An opening  140  is formed so as to extend through each of the sides  132  and  134  of substrate  102  adjacent one end  142 . For purposes of this disclosure the one end  142  will be referred to as the rear end and the opposite end, designated  144 , will be referred to as the front or forward end. 
     Outer tube  104  is a generally hollow cylinder with a rectangular alignment notch  144  cut out of the periphery at one end. Further, tube  104  is designed and constructed to be fixedly engaged in opening  140  of substrate  102  by some convenient means, such as welding or the like. In the assembly process notch  144  is designed to mate with a small rectangular protrusion  146  to accurately align outer tube  104  within substrate  102 . This alignment is described because outer tube  104  includes a circumferentially extending arcuate slot  150  through which slave link  108  extends, as will be described in more detail presently. In a preferred embodiment, substrate  102  and most of the other components can be formed of metal, such as sheet metal, sheet steel, or a sufficiently rigged and rugged plastic so that tube  104  could be fixed in place for example by frictional engagement, welding or some compatible adhesive. 
     Inner tube  106  is a generally hollow cylinder with one end  152  closed to form a generally circular cylindrical cup-shape. A mounting hole  154  is formed in end  152 . Inner tube  106  is designed and formed to be fixedly attached to a seat back  155  or the like (see  FIG. 14 ) and is received within outer tube  104  for relative rotation therewith. Thus, as will be better understood from the following description, armrest  100  is substantially supported on a seat back or the like by outer tube  104  rotatably nested over inner tube  106 . It will of course be understood that inner tube  106  could be a short section, as shown and be attached to, for example, a side of a seat back  155  or could extend through the seat back and out the other side to provide a mount for a second infinitely movable armrest  100 , if desired. 
     With additional reference to  FIG. 12 , slave link  108  and lock link  120  are clearly illustrated in the assembled position. Slave link  108  is an elongated link or strip of rigid material formed with mounting holes  156  and  158  adjacent opposite ends. Lock link  120  is an elongated link or strip of rigid material formed with a mounting hole adjacent the rear end. A pivot pin  160  extends through hole  156  in slave link  108  and into mounting hole  154  in the end of inner tube  106 . A pivot pin  162  extends through hole  158  in slave link  108  and into the mounting hole adjacent the rear end of lock link  120  so that lock link  120  is pivotally attached to slave link  108  and moves with a reciprocal movement within the guide. 
     Circumferentially extending slot  150  has a length which limits upper and lower rotational movement of substrate  102  and therefore, armrest  100 . As substrate  102  is rotated, outer tube  104  rotates relative inner tube  106  and slot  150  moves relative to slave link  108 . Relative movement of slave link  108  within slot  150  is limited by contact of slave link  108  with the opposing ends of slot  150 . In other words when slave link  108  contacts the upper end of slot  150 , downward movement of substrate  102  is stopped, and when slave link  108  contacts the lower end of slot  150 , upward movement of substrate  102  is stopped. Thus, the range of movement of armrest  100  can be modified by increasing or decreasing the length of slot  150 . 
     In this embodiment lock mechanism  122  includes a pair of lock plates  164  each having a slot defined therethrough with dimensions slightly larger than the cross-sectional dimensions of lock link  120  and lock link  120  is positioned within the slots for lateral movements therein. Lock plates  164  are rotatably held within the channel of substrate  102  by means of a U-shaped lock pivot  166 . Lock pivot  166  extends through openings in the channel bottom  130  and the upper ends of lock plates  164  are held therein by lock link  120  for limited pivotal movement. A compression spring  170  is positioned around lock link  120  abutting lock plates  164  on the forward side. A spring plate  172  having a slot therethrough is positioned around lock link  120  between compression spring  170  and pins  136 ,  137  through substrate  102 . Thus, spring plate  172  holds compression spring  170  against lock plates  164  so that lock plates  164  are biased rearwardly or into a locked position. That is, lock link  120  is frictionally engaged by lock plates  164  which cause a “binding” that prevents forward movement of lock link  120  through lock plates  164 . This binding results in substrate  102  (and armrest  100 ) being locked in the particular vertical orientation selected, i.e. substrate  102  and thus the armrest cannot move downwardly. 
     In this embodiment manually operated adjustment lever  124  of locking mechanism  122  is an elongated element bifurcated adjacent the rear end so as to form an elongated slot  125 . Holes  126  adjacent the rear end are used to pivotally mount lever  124  on pin  134  within the channel of substrate  102  with lock link  120  extending through slot  125 . An optional return spring  180  is held on pin  137  and biases lever  124  downwardly and helps eliminate unwanted movement. Thus, in the at-rest position illustrated in  FIG. 12 , locking mechanism  122  binds lock link  120  in whatever position it is in. By manually lifting lever  124  upwardly, generally by pressing upwardly on portion  182  which is externally accessible, lever  124  bears against the bottom of lock plates  164 , pivoting lock plates  164  forwardly and thereby temporarily releasing lock link  120  for forward movement. It will be understood that lock mechanism  122  does not prevent upward movement of substrate  102  and the associated armrest. Thus, substrate  102  and the associated armrest can simply be moved upwardly to any desired position and locking mechanism  122  holds it in the desired position against downward movement. To adjust substrate  102  and the associated armrest downwardly, the operator simply presses upwardly on portion  182  and moves it to the desired position. 
     Referring additionally to  FIGS. 13 and 14 , a housing  190  is illustrated that surrounds and encloses substrate  102  and the associated mechanism to form infinitely adjustable armrest  100 . As can be seen, portion  182  of manually operated adjustment lever  124  is externally accessible through housing  190  for convenient access and use. 
     Various changes and modifications to the embodiments herein chosen for purposes of illustration will readily occur to those skilled in the art. To the extent that such modifications and variations do not depart from the spirit of the invention, they are intended to be included within the scope thereof, which is assessed only by a fair interpretation of the following claims. 
     Having fully described the invention in such clear and concise terms as to enable those skilled in the art to understand and practice the same, the invention claimed is: