Patent Publication Number: US-6702386-B2

Title: Height and pivot-adjustable chair arm

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates in general to an office chair arm rest and in particular to an office chair arm rest that can be adjusted in height and rotation about a vertical axis. 
     2. Description of Related Art Including Information Disclosed Under 37 C.F.R. §§1.97 and 1.98 
     There are many different patents disclosing chair arm rests that can be adjusted vertically in height and rotationally in a horizontal plane to conform to the arms of the user of the chair. 
     Some of these patents disclose hydraulic actuators for raising and lowering the arm rest, such as U.S. Pat. Nos. 5,931,536; 5,908,221; and 5,765,804. 
     Others disclose some manually-activated support shafts that can be manually raised and lowered with some type of engaging device. Some of such patents are U.S. Pat. Nos. 5,393,124; 5,971,484; 6,053,578; 5,895,095; 5,749,628; 5,641,203; 5,647,638; and 5,407,249. 
     Other patents disclose strictly horizontally-adjustable arm rests such as disclosed in U.S. Pat. Nos. 5,590,934; 5,655,814; 5,884,976; 5,944,486; and 6,045,191. 
     All of these patents disclose complex mechanisms for raising and lowering the arm rest and for pivoting the arm rest in a horizontal plane. 
     It would be in a desirable to have an arm rest that can be moved both in the vertical plane and rotated horizontally with simple mechanisms that are easily constructed and easily usable. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a height and pivot-adjustable office chair arm assembly that is operated vertically to provide different arm rest heights using a gas cylinder and is rotated in a horizontal plane about a vertical axis using a simple radially-biased ball bearing and detent assembly that is operable independent of the mechanism for raising and lowering the chair arm rest. 
     The chair arm assembly has an arm rest assembly thereon and comprises an arm support having one end for attaching the chair arm assembly to a chair and having an opposite end. A gas cylinder cooperates with the arm support for movement in the vertical direction to raise and lower the arm rest assembly to any selected vertical position. A shroud surrounds and vertically moves in relation to at least a portion of the arm support and has an upper end. The shroud is connected to the gas cylinder for vertical movement by the gas cylinder and an arm rest pivot support attached only to the shroud receives the arm rest assembly and enables the arm rest assembly to pivot in a horizontal plane thereby allowing the arm rest to assume a selected rotational position independent of the operation of the gas cylinder mechanism. 
     The shroud is formed of a hollow tube that slidedly receives the arm support. It has a cross-sectional shape that conforms to the cross-sectional shape of the arm support and is such that the shroud can move vertically with respect to arm support but is non-rotatable with respect to the arm support. In the preferred embodiment, the cross-sectional shape of the shroud and the arm support are ovate. 
     The arm rest assembly itself has an upper arm pad assembly for receiving the arm of the user, and a lower arm pad assembly that has a first end attached to the upper arm pad assembly, and a second end having a bearing and ring assembly that is associated with the arm rest pivot support that is attached only to the shroud. There is a detent carrying device fixedly attached to the lower end of the shroud to mate with the bearing support ring and assist in holding the arm rest in a given horizontal rotational position. The detent carrying device matingly engages the at least one bearing and spring assembly to enable the bearing to rotatively move from one detent to another as the arm rest pivot support plate is rotated about a substantially vertical axis to establish a given rotational position of the arm rest. 
     The novel detent-carrying device has a plurality of vertically-oriented detents and there are at least one bearing and spring assembly on the lower arm pad assembly such that each of the bearings radially engages a different one of the detents for releasably holding the arm rest in a given rotational position. In the preferred embodiment, the bearings are ball bearings biased radially against elongated vertically-positioned detents by springs or other resilient devices. The bearings could also be roller bearings that would also be biased radially against the detents by the springs. In the preferred embodiment, at least two sets of three detents are disposed on diametrically-opposed sides of the shroud, and each of the at least two bearings radially and releasably engages a corresponding set of detents. The top of the shroud is circular with an outer periphery for carrying the vertically-oriented detents. The bearing and spring assemblies are spaced from each other with each of the bearings releasably and radially engaging corresponding detents and enabling the arm rest assembly to assume any selected horizontal position represented by the detents. In the preferred embodiments, the detents allow 40° rotation of the arm rest assembly. 
     Further, the novel arm rest assembly comprises a substantially V-shaped arm pad assembly having first and second legs joined at one end. The first leg forms a substantially-horizontal upper rest for the user&#39;s arm, and the second leg is a lower rest for attachment for the shroud upper end, and the first leg is longer than the second leg. 
     In the preferred embodiment, the second leg is at least partially hollow with a lever actuator extending from the hollow portion of the second leg engaging and operating a lever extending through the partially-hollow second leg between the lever actuator and the gas cylinder such that the lever actuator can be used to move the lever to actuate the gas cylinder and enable raising and lowering of the arm rest assembly. 
     Thus, it is an object of the present invention to provide an arm rest for a chair that can be adjusted both vertically and rotationally in the horizontal plane about the vertical axis for adapting to a particular user. 
     It is also an object of the present invention to provide an arm rest assembly that is adjustable in the vertical direction with the use of a gas cylinder, and in the horizontal rotational position by a bearing radially biased against the detent assembly. 
     It is still another object of the present invention to provide a chair arm rest assembly that is movable in a vertical direction with a gas cylinder having an upper end attached to a shroud surrounding an arm support in which the gas cylinder can move vertically with the cross-sectional shape of the shroud and the arm support being such that the shroud can move vertically with respect to the arm support but cannot be rotated. 
     It is another object of the present invention to provide the shroud and the arm support with a cross-sectional ovate shape to allow sliding vertical relative motion but to prevent horizontal rotation with respect to each other. 
     It is also an object of the present invention to provide an arm rest assembly that has substantially V-shaped arm pad assembly having first and second legs joined at one end with the first leg forming a substantially-horizontal upper rest for the user&#39;s arm and the second leg forming a lower rest for attachment to the shroud upper end with the first leg being longer than the second leg. 
     Thus, the present invention relates to a height and pivot-adjustable office chair arm assembly having an arm rest assembly thereon and comprising an arm rest support having one end for attaching the chair arm assembly to a chair and having an opposite end; a gas cylinder cooperating with the arm rest support for movement in the vertical direction to raise and lower the arm rest support to any selected vertical position; a shroud surrounding and vertically movable in relation to at least a portion of the arm support and having an upper end; the shroud being connected to the upper end of the gas cylinder for vertical movement; and an arm rest pivot support attached only to the shroud for receiving the arm rest assembly and enabling the arm rest assembly to pivot in a horizontal plane thereby allowing the arm rest assembly to assume any selected rotational position. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other objects of the present invention will be more fully described when taken in conjunction with the following detailed description of the drawings wherein like numerals represent like elements and wherein: 
     FIG. 1 is a side exploded view of the novel arm rest assembly; 
     FIG. 2 is a side cross-sectional view of the novel arm rest assembly; 
     FIG. 3 is a bottom view of the lower arm pad assembly of the arm rest; 
     FIG. 4 is a perspective exploded view of the shroud and arm support illustrating the circular detent-carrying device that is attached to the upper end of the shroud; 
     FIG. 5 is a perspective view of the novel arm rest assembly, the arm rest shown in the forward-facing position; 
     FIG. 6 is a side view of the arm chair assembly shown in FIG. 5; 
     FIG. 7 is a top view of the novel arm rest assembly illustrating rotation of 20° inwardly; 
     FIG. 8 is a top view of the novel arm rest assembly showing a 20° rotation outwardly; 
     FIG. 9 is a top view of the novel arm rest assembly illustrating the arm rest in the centered forward position; 
     FIG. 10 is a side view of the novel arm rest assembly illustrating the arm rest assembly in its bottom position; 
     FIG. 11 is a side view of a novel arm rest assembly illustrating the arm rest in its middle vertical position; and 
     FIG. 12 is a side view of a novel arm rest assembly illustrating the arm rest in its top or most elevated position. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S) 
     FIG. 1 is an exploded side view of the novel height and pivot-adjusting office chair arm assembly  10 . It has an arm support  12  having one end  14  (shown in FIG. 2) for attaching the arm chair assembly  10  to a chair and having an opposite end  15 . A gas cylinder  22  is placed within the arm support  12  for movement in the vertical direction to raise and lower arm rest  20  to any selected vertical position. A shroud  16  surrounds and is vertically movable in relation to at least a portion of the arm support  12 . The shroud  16  has an upper end  17 . The shroud  16  is connected to the gas cylinder  22  with a press-fit for vertical movement by the gas cylinder. An arm rest support plate  18  is attached only to the shroud with the bolts  19  for receiving the arm rest assembly  20  and enabling the arm rest assembly  20  to pivot in a horizontal plane thereby allowing the arm rest assembly  20  to assume any selected rotational position. It can be seen in FIGS. 2 and 4 that the shroud  16  comprises a hollow tube for slidably receiving the arm support  12 , and as can best be seen in FIG. 4 has an ovate cross-sectional shape that conforms to the cross-sectional shape of the arm support  12  and is such that the shroud can move vertically with respect to the arm support  12  but is non-rotatable with respect to the arm support  12 . Obviously, the cross-sectional shape of shroud  16  and the arm support  12  could be of any shape other than cylindrical so that the shroud can move vertically with respect to the arm support but cannot be rotated. The ovate shape is preferred. The arm rest assembly  20  comprises an upper arm pad assembly  28  for receiving the arm of the user and a lower pad assembly  30  having a first end  32  attached to the upper arm pad assembly  28 , and a second end  34  attached to the arm rest pivot support  18 . A detent means  36 , best shown in FIG. 4, the upper end  17  of the shroud  16  to assist in holding the arm rest assembly  20  in a given horizontal rotational position. The lower arm pad assembly  30  has at least one bearing and spring assembly  40 , best shown in FIG. 3, for matingly engaging the detent means  38  on the shroud  16  such that the bearing  40  may rotatively move from one detent means  38  to another as the arm rest pivot support  18  is rotated about a substantially-vertical axis to establish a given rotational position of the arm rest assembly  20 . 
     As can be seen best in FIGS. 3 and 4, a plurality of vertically-oriented detents  42  are located in the shroud  36  and at least one bearing and spring assemblies,  40 ,  44  on the lower arm pad assembly  30  such that each of the bearings  40  radially engages a different opposing detent  42  for releasably holding the arm rest assembly  20  in the given rotational position. As can be seen in FIGS. 3 and 4, in the preferred embodiment, the bearings are ball bearings biased radially against elongated vertically-positioned detents  42  by springs  44 . Of course, roller bearings could be used as the bearings  40 . As can be seen in FIG. 4, at least two sets of three detents  42  are disposed on diametrically-opposed sides of the detent-carrying device  36 . Each of the at least two bearings  40  radially and releasably engage a corresponding set of detents  42  by means of the springs  44  shown in FIG.  3 . It can be seen in FIG. 4 that the detent-carrying device  36  is circular in shape and has an outer periphery  37  for carrying the vertically-positioned detents  42 . Also as can be seen in FIG. 3, the bearing and spring assemblies  40 ,  44  are spaced from each other with each of the bearings  40  releasably and radially engaging corresponding detents  42  and enabling the arm rest assembly  20  to assume any selected horizontal position represented by the detents  42 . It can be seen that since the bearings roll against the outer periphery of the shroud  16  in a bearing race  52 , that the detent-carrying device  36  allows 40° rotation of the arm rest assembly  20 . 
     As can best be seen in FIGS. 1 and 2, the arm rest assembly  20  has a substantially V-shaped arm pad assembly having a first leg  28  and second leg  30  joined at the one end  32 . The first leg  28  forms a substantially-horizontal upper rest for the user&#39;s arm, and the second leg  30  is a lower rest for attachment to the upper end  17  of the shroud  16 . It will be noted that the first leg  28  is longer than the second leg  30 . It can also best be seen in FIG. 2 that the second leg  30  is at least partially hollow. A lever actuator  46  extends from the hollow portion of the second leg  30  with a lever  48  extending through the partially-hollow second leg  30  between the lever actuator  46  and the gas cylinder  22  such that the lever actuator  46  can be used to move the lever  48  to actuate the gas cylinder  22  and in a well-known manner and enable raising and lowering of the aim rest assembly  20 . 
     It will be noted that FIG. 3 is a bottom view of the lower arm pad assembly  30  taken along line  3 — 3  in FIG.  1 . 
     Thus, there has been disclosed a novel height and pivot-adjustable arm rest assembly  20  for a chair comprising a hollow main arm support  12  for rigid attachment to the chair at  14 ; a gas cylinder  22  in the hollow main support arm  12  for raising and lowering the arm rest assembly  20 ; a hollow housing or shroud  16  surrounding the hollow main arm support  12  for relative, slidable motion in the vertical direction and having an upper portion  17  attached to the upper end of the gas cylinder preferably by a press-fit for movement therewith; a circular detent means  36  mounted on the upper portion  17  of the hollow housing or shroud  16  for establishing arcuate arm rest positions; an arm pad assembly  20  forming a portion of the arm rest assembly  10  for rigid to the upper portion  17  of the hollow shroud  16 ; and a radially-biased bearing and spring assembly  40  associated with the lower second leg  30  for engaging detents  42  in the circular detent means  36  such that the arm rest assembly  20  may be rotated to any desired arm rest position and releasably held in place by the bearing and spring assembly  40 ,  44 . 
     Both the hollow main arm support  12  and the hollow housing  16  have corresponding cross-sectional shapes that prevent rotation of the housing  16  with respect to the main arm support  12 , but allows relative vertical movement of the housing  16  with respect to the main arm support  12 . 
     In one preferred embodiment, the bearings  40  are roller bearings in a bearing cage  52  with the long bearing axis in the vertical plane for radially engaging the detents to releasably hold the arm rest assembly  20  in the given rotated position. The bearings could be ball bearings in bearing cage  52  for radially engaging the detents  42  to releasably hold the arm rest assembly in the given rotated position. 
     FIG. 5 is a perspective view of the novel office chair arm assembly  10  with the arm rest assembly  20  being centered and pointing in the forward direction. 
     FIG. 6 is a side view of the office chair arm assembly  10  shown in FIG.  5 . 
     FIGS. 7,  8  and  9  illustrate, respectively, a top view of the office chair assembly  10  with the arm rest assembly  20  rotated 20° inwardly, 20° outwardly, and centered. 
     FIGS. 10,  11  and  12  are side views of the novel office chair arm assembly  10  illustrating the arm rest assembly  20  in the lowest, the middle, and the highest arm rest positions. 
     While the present invention has been described as in connection with a preferred embodiment thereof, it will be apparent to those skilled in the art that many changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, it is intended by the appended claims to cover all such changes and modifications encompassed by the spirit and scope of the appended claims.