Abstract: A seat structure for an operator that is set in a cab of a construction machine such as a wheel loader includes: a suspension equipment fixed to a floor frame; a plate-shaped attachment bracket attached on the suspension equipment; a seat and a work equipment console juxtaposed to each other on the attachment bracket. The seat is attached to the attachment bracket via slide rails in a manner slidable back and forth. The work equipment console is also attached to the attachment bracket via a slide rail in a manner slidable back and forth.

Abstract: An armrest structure includes a cover and a controlling member which has a pressing portion and a rack portion respectively formed on two sides thereof. A sliding plate has a sliding protrusion and multiple teeth which are engaged with the rack portion. A fixing plate has a sliding groove and the sliding protrusion is slidably engaged with the sliding groove. A fixing device has a sliding area and two first rails. The sliding plate is engaged with the first rails. The fixing device has a recessed area in which the fixing plate is located. The fixing device has multiple engaging teeth engaged with the rack portion, and two guide grooves. A base is connected with the cover and has two second rails which are engaged with the two guide grooves. A height adjustment device is connected to a slot of the fixing device and fixed to the fixing plate.

Abstract: A chair, includes a seat structure and a backrest structure arranged pivotally to the seat structure. An armrest is arranged pivotally to the backrest structure through a pivotal connection, and a link mechanism is journalled to the structures of the seat and the backrest, respectively, the link mechanism actuating and controlling the armrest to maintain its pivotal orientation in any pivotal position of the backrest relative to the seat. The armrest is adjustable in the length direction of the backrest through the pivotal connection which is arranged displaceable on the backrest structure, and the pivotal orientation of the armrest is controlled via a sliding engagement between a lever arm, adjoining the armrest at an angle thereto, and an actuator link included in the link mechanism and displaceable thereby with respect to the backrest so as to extend substantially in the length direction of the backrest in all its positions of displacement.

Abstract: An expandable armrest of a wheel chair includes a fixed part having a first pivotal portion which includes a first pivotal hole. A movable part is pivotably connected to the first pivotal portion of the fixed part by its second pivotal portion. A first transverse hole and a second transverse hole are defined in the second pivotal portion. A slide member is slidably inserted into the slots of the second pivotal portion and has an inclined hole in which an engaging member is engaged. The engaging member has a first end and a second end. A trace that the engaging member moves in the inclined hole constantly intersects a trace that the first end moves in the first transverse hole and a trace that the second end moves in the second transverse hole, such that the movable part is positioned by controlling the movement of the slide member.

Abstract: An adjustable sliding armrest that may be extendable in length and varied in rotational position is provided. The armrest generally includes a support member, a slide member, a locking mechanism, and a tilt adjusting mechanism. The support member and slide member are in slidable communication with one another, and the locking mechanism may serve to lock the position of the slide member with respect to the support member. Moreover, the tilt adjusting mechanism may be utilized to selectively increase or decrease the tilt angle of the armrest. Such features allow users of various arm lengths to adjust the armrest to their comfort.

Abstract: An arm support, comprising an arm supporting element, connected via a connecting device with a lift device, wherein the arm supporting element has a longitudinal direction between a front end and a rear end and is connected via a tilting axis (E) with the connecting device, which tilting axis (E), in top plan view, is situated between the front end and the rear end, wherein the lift device comprises compensation means for bearing the weight of the arm support and a load borne thereon, in particular an arm of a user.

Abstract: An adjustable sliding armrest that may be extendable in length and varied in rotational position is provided. The armrest generally includes a support member, a slide member, a locking mechanism, and a tilt adjusting mechanism. The support member and slide member are in slidable communication with one another, and the locking mechanism may serve to lock the position of the slide member with respect to the support member. Moreover, the tilt adjusting mechanism may be utilized to selectively increase or decrease the tilt angle of the armrest. Such features allow users of various arm lengths to adjust the armrest to their comfort.

Abstract: An armrest apparatus and chair including one or more armrest apparatuses are disclosed. Each armrest apparatus includes an armrest member attached to at least one chair component. The armrest member has a first aperture and a second aperture. A first plate is positioned above the armrest member. The first plate has a longitudinal slot that is transverse to the first and second apertures. An armrest cover is attached to the first plate. A resilient device is positioned between the first plate and the armrest cover or between the first plate and the armrest member. The resilient device has a first hole sized and configured to receive the first member and a second hole sized and configured to receive the second member. A first member extends through the first aperture, first hole and the longitudinal slot and a second member extends through the second aperture, second hole and the longitudinal slot.

Abstract: An office chair is provided with includes a chair arm assembly on each opposite side thereof for supporting the arms of a user. The arm assemblies each include a latching assembly to permit adjustment of the height of an arm cap thereof while maintaining the arm cap at a selected elevation. The latch assembly is engageable with an inner liner provided within a support post. Further, the armrest assembly has a plurality of interconnected and relatively movable plates which permit adjustment of the angular orientation of the arm cap along with adjustment of the arm cap in the front-to-back direction and the side-to-side direction.

Abstract: An armrest includes an armrest base having a guiding groove. A support is mounted below the armrest base. The support includes a top end having a restraining plate. An engaging member includes a body having an upper portion. A slider is formed on the upper portion of the body. The slider includes two arms slideably abutting two lateral walls of the guiding groove, allowing relative sliding movement between the slider and the armrest base along the guiding groove. The engaging plate further includes an insertion plate located below the restraining plate. The engaging member can be rotatably received in the compartment of the support. The top end of the support can include an annular portion having a plurality of annularly spaced teeth in the compartment. A groove is formed between two adjacent teeth. A positioning member projects downwardly from the engaging member and is selectively engaged in one of the grooves.

Abstract: An armrest includes an armrest base having a guiding groove. A support is mounted below the armrest base. The support includes a top end having a restraining plate. An engaging member includes a body having an upper portion. A slider is formed on the upper portion of the body. The slider includes two arms slideably abutting two lateral walls of the guiding groove, allowing relative sliding movement between the slider and the armrest base along the guiding groove. The engaging plate further includes an insertion plate located below the restraining plate. The engaging member can be rotatably received in the compartment of the support. The top end of the support can include an annular portion having a plurality of annularly spaced teeth in the compartment. A groove is formed between two adjacent teeth. A positioning member projects downwardly from the engaging member and is selectively engaged in one of the grooves.

Abstract: A sliding arm mechanism for attaching to an arm of a wheelchair is provided herein. One concept is directed to a sliding arm mechanism that includes a main portion and an inner cavity. The sliding arm mechanism also includes a slide rail, which is adapted to be housed within the inner cavity of the main portion. The slide rail and the main portion are slidably coupled to allow the main portion to move laterally over the slide rail in a direction parallel to the top part of the arm of the wheelchair, thus allowing the main portion to move between a first position and a second position. In some embodiments, the first position corresponds to a full-length position and the second position corresponds to a desk-length position, such that a user can adjust the sliding arm mechanism to access a desk or table.

Abstract: An aircraft seat has an adjustable armrest in which the armrest platform is supported by a hinged attachment to an armrest support member. The hinged attachment between the armrest platform and the arm support member is located at the wrist-end of the arm support member near the aircraft control stick. The armrest platform and the armrest support are locked into position by means of telescoping struts that are controlled at the wrist-end of the arm platform member. The telescoping struts can be selectively locked to create triangular and/or quadrilateral trusses that lock the armrest firmly into position and may include springs or other elements to bias the armrest platform up and forward so that the armrest “floats” when the telescoping struts re released.

Abstract: A control system for a construction vehicle, such as a motor grader, is provided. The control system includes a plurality of joysticks supported by an operator seat assembly of the motor grader.

Abstract: A hinged fitting for an article of seating furniture, which has a supporting element which is capable of being swung, by means of a swing over joint, from a basic position to the side of the seat to an end position that is located in front of the seat to form a leg rest, with the top or lateral surface of the supporting element in the basic position becoming the bottom surface thereof in the end position, has a displacement device, by means of which the end position of the supporting element can be displaced to a position in front of the seat or the base frame of the article of seating furniture beyond the position defined by the swing over joint.

Abstract: An arm support, comprising an arm supporting element, connected via a connecting device with a lift device, wherein the arm supporting element has a longitudinal direction between a front end and a rear end and is connected via a tilting axis (E) with the connecting device, which tilting axis (E), in top plan view, is situated between the front end and the rear end, wherein the lift device comprises compensation means for bearing the weight of the arm support and a load borne thereon, in particular an arm of a user.

Abstract: An armrest adjustment device is revealed. The armrest adjustment device includes an armrest arranged at a top surface of an armrest support. The lower part of the armrest support is connected to a chair seat. The armrest can be adjusted to move forward and backward in relation to the chair seat. A first component is mounted in the armrest. The first component is assembled with and fixed on the armrest support so that the armrest can be moved forward and backward in relation to the first component. Moreover, a second component is arranged between the armrest and the armrest support. Instead of the first component, the second component is assembled with and fixed on the armrest support. Thus the armrest is moved in the left/right direction in relation to the second component.

Abstract: The present invention provides a wheelchair armrest adjusting mechanism comprising a support unit having a horizontal support connected to a top of an upright support, and a plurality of locking units located one side of the horizontal support; wherein an armrest has a slide channel for engaging with the horizontal support, a stop hole for creating a passage to the slide channel in order to fit one of the locking units when the stop hole is aligned with the locking unit, and a control unit fitted in the stop hole for pushing against the locking unit. When the control unit is pushed and held, the armrest can be slid along the horizontal support to align with one of locking units; and when the control unit is released, the locking unit is pushed into the stop hole and thereby locks the armrest in place.

Abstract: A chair arm adjustment device according to embodiments of the present invention includes an arm pad base slidably coupled to the arm support, the arm pad base sliding substantially horizontally in two degrees of freedom with respect to the arm support within a range of motion of the arm pad base with respect to the arm support, and an arm brake assembly coupled with the arm pad base, the arm brake assembly moveable between a locked position in which the arm brake assembly substantially inhibits movement of the arm pad base relative to the arm support and an unlocked position in which the arm brake assembly does not substantially inhibit movement of the arm pad base relative to the arm support, wherein the arm brake assembly moves from the unlocked position to the locked position at any position of the arm pad base within the range of motion.

Abstract: This invention relates to a vehicle seat track assembly. The assembly comprises a first track member having an upwardly facing bearing surface and a second track member for attachment to a vehicle seat, the second track member having a downwardly facing bearing surface. A cage is disposed between the first track member and the second track member. The cage carries a rolling element that is in rolling engagement with the upper and lower bearing surfaces to provide longitudinal movement of the first track member relative to the second track member. The cage is provided with at least one pad section for engaging at least one of the upwardly and downwardly facing bearing surfaces. In an unloaded state, the at least one pad section separates the upwardly and downwardly facing bearing surfaces from each other by a distance which is greater than the diameter of the rolling element.

Abstract: An armrest for a vehicle seat includes an armrest cushion, an armrest body connected to the armrest cushion, a connection part configured to connect the armrest body to at least one of a back rest of the vehicle seat or to a vehicle interior, a tilting device disposed between the armrest body and the armrest cushion and configured to adjust a position between the armrest body and the armrest cushion, and an arresting device disposed between the armrest body and the armrest cushion and configured to fix the position of the armrest cushion relative to the armrest body. A swivel axis is, formed in the connection part running substantially horizontal and parallel to the back rest. The tilting device has a rotation axis arranged parallel to the swivel axis and the rotation axis moveable towards the back rest linearly against a force of a spring.

Abstract: A sliding armrest for use in an automotive vehicle. The sliding armrest including a lower cover, and a lower rail case arranged on a top surface of the lower cover. The armrest includes a guide arranged on the surface of the lower rail case and an upper case cover having a plurality of bosses extending from the surface thereof with the bosses contacting the guide. The sliding armrest also includes a force member arranged between the upper case cover and the guide.

Abstract: The invention relates to an operator workplace of a construction machine, especially a milling machine for processing a road surface, comprising a seat with a seating surface, an armrest arranged to the side of the seating surface and comprising an arm supporting surface, and at least one control element arranged on the armrest for controlling at least one machine function. The invention further relates to a construction machine with such an operator workplace.

Abstract: An adjustable armrest for a vehicle seat comprising an armrest housing pivoted on a seat back frame and a pair of locking elements in the housing, one of which is adjustable and the other being fixed. A seat back stop is engageable with the adjustable locking element. A seat occupant, using an armrest release mechanism, may adjust the relative positions of the locking elements to change a desired active position of the armrest. A memory feature permits return of the armrest to the desired active position from an upright stowed position.

Abstract: An upper body appendage support apparatus having an articulating parallelogram support structure connected to an articulating upper body appendage support structure, the latter accommodating a user's forearm, wrist, and/or heel-of-hand. The apparatus analogously jointed to the human arm and moving synchronously therewith.

Abstract: An armrest support assembly for chair includes an upright support member, an outer tube movably and adjustably mounted on the support member and two opposite resting members each secured in the outer tube to move in concert with the outer tube and each abutting the support member during movement of the outer tube relative to the support member. Thus, when the outer tube is moved relative to the support member, the inner wall of each of two resting members presses the support member closely and tightly to stabilize movement of the outer tube relative to the support member, so that the outer tube is moved relative to the support member smoothly and stably without incurring vibration.

Abstract: A universal reclining armrest system for use with an articulated examination chair. The system includes an armrest adapter having a universal aperture for receiving a post portion of an armrest assembly. The armrest adapter further includes a splined peg for coupling to a pivoting mechanism of an articulated chair. The pivoting mechanism enables the chair to move throughout an operable range of motion while maintaining a fixed rotational position of an attached armrest adapter. The armrest assembly further includes an adjustable joint to provide 360° of rotational adjustment to the armrest relative to the fixed position of the armrest adapter.

Abstract: An adjustable armrest for a vehicle seat comprising an armrest housing pivoted on a seat back frame and a pair of locking elements in the housing, one of which is adjustable and the other being fixed. A seat back stop is engageable with the adjustable locking element. A seat occupant, using an armrest release mechanism, may adjust the relative positions of the locking elements to change a desired active position of the armrest. A memory feature permits return of the armrest to the desired active position from an upright stowed position.

Abstract: A rotatable armrest assembly comprises: an armrest support adapted to be connected to a base of the child car seat and having an insert hole; and an armrest having top and bottom ends that are opposite to each other in an axial direction, and provided with a shaft that extends into the insert hole so as to permit the armrest to be rotatable relative to the armrest support about an axis of the shaft that extends in the axial direction.

Abstract: An armrest, in particular for an office chair, preferably has a height-adjustable armrest column and an arm support positioned on the armrest column. In order to improve the operation of an armrest of this type, it is recommended that a multi-function bearing head disposed on the armrest column be fitted, with a rotational, longitudinal and lateral adjustment mechanism for the arm support.

Abstract: An armrest device comprises an armrest base plate on the upper end of an armrest support rod. A support block is provided on the armrest base plate. An engagement portion of the support block engages in a slot of the armrest base plate. A plurality of grooves are formed on a projection along the slot. An elastic tongue of the support block engages with the projection to allow the armrest base plate to slide back and forth smoothly. The armrest support rod is surrounded by an intermediate tube and an armrest support tube. A turning lever in the armrest support rod is pivotally mounted to an operating lever on the upper end of the armrest support rod. A pin which passes through a hole of the turning lever engages in an opening of the intermediate tube. The opening comprises a vertical elongate portion and a plurality of horizontal engagement portions. The pin selectively engages in any one of the engagement portions to allow the armrest to be held at respective height.

Abstract: An office chair is provided with includes a chair arm assembly on each opposite side thereof for supporting the arms of a user. The arm assemblies each include a latching assembly to permit adjustment of the height of an arm cap thereof while maintaining the arm cap at a selected elevation. The latch assembly is engageable with an inner liner provided within a support post. Further, the armrest assembly has a plurality of interconnected and relatively movable plates which permit adjustment of the angular orientation of the arm cap along with adjustment of the arm cap in the front-to-back direction and the side-to-side direction.

Abstract: An armrest for a motor vehicle seat includes an armrest body configured to coupled to a fixing mechanism. The armrest body includes axle pins and stop pins and the fixing mechanism includes a pivot bearing and a stop groove. The axle pins are configured to insert into the pivot bearings and pivot about an axis of rotation. The distance between the stop pins is smaller than the distance between the pivot bearings.

Abstract: A forward/rearward slidable and upwardly pivotable armrest supported upon an open center console. Retractable pins associated with inner underside locations of the armrest are displaced upon actuation of a lever component associated with the armrest, and which selectively reseats the armrest at linear travel locations along first and second rails defined upon the side walls of the console. Seating locations established between a slidable and upper support portion of the armrest and the recessed stops defined along inwardly facing surfaces of the rails permit the armrest to be translated to either forward or rearward locations of a center nominal position, relative to a fixed lower carriage with pivot support bracket.

Abstract: An adjustable armrest mechanism is provided, which is adapted to be coupled to a vehicle frame. The armrest mechanism comprises a base fixed to the vehicle frame, armrest apparatus movably coupled to the base such that the armrest apparatus moves relative to the control handle and pivots about a virtual pivot point in front of the control handle, and a locking device for releasably locking the armrest apparatus to the base in one of at least two positions.

Abstract: A machine includes a seat assembly and a mechanical strut attached to the seat assembly. The mechanical strut, free of pneumatic seals, is positioned to move at least a portion of an armrest of the seat assembly along a horizontal axis. A length adjustment mechanism is movable to release a friction lock mechanism within the mechanical strut. The mechanical strut is telescopically movable through a continuous range of armrest lengths when the friction lock mechanism is released.

Abstract: Disclosed herein is a width control device which automatically controls the width of an armrest, provided in a seat of a vehicle, in response to the body type of a passenger, thus enabling the passenger to sit in a comfortable position.

Abstract: A seat for use in an aircraft having a floor is disclosed. The seat has a support assembly adapted to be secured to the floor, a seat having a central portion and a rear portion, a seat back pivotably coupled to the support assembly for movement between an upright position and a reclined position relative to the support assembly. A pivot assembly couples the central portion of the seat to the support assembly for permitting the seat to pivot about a pivot axis relative to the support assembly. A connector assembly couples the rear portion of the seat to the seat back for causing the rear portion of the seat to pivot downwardly about the pivot axis in unison with the seat back as the seat back moves from the upright position to the reclined position A method of construction of an aircraft seat frame is also disclosed. An armrest for an aircraft seat is further disclosed.

Abstract: A massage chair of the present invention includes an electric reclining mechanism for moving a backrest into different sloping positions, left and right holding mechanisms for respectively holding user's left and right forearms, and a controller for controlling operations of the mechanisms. The controller separately controls operations of the electric reclining mechanism and the left holding mechanism as well as operations of the electric reclining mechanism and the right holding mechanism. When controlling the former operations, the controller controls (A) allow the left holding mechanism to hold the left forearm, (B) allow the electric reclining mechanism to recline the backrest to any of the different sloping positions, (C) allow the electric reclining mechanism to raise the backrest to any of the different sloping positions, and (D) allow the left holding mechanism to release the left forearm. Similarly, the controller controls the latter operations.

Abstract: A control console includes a body supporting a plurality of controls, a base, and first and second legs each having a first end pivotably connected to the body and a second end pivotably connected to the base. The legs are shiftable between a first position projecting over a first end of the base, a second position projecting over a second end of the base and a third position between the first and second positions. At least one spring is provided to bias the legs toward the third position, and a motor may included for shifting the legs.

Abstract: An armrest for a vehicle seat includes a seat cushion and a backrest. The armrest is intended to be turned around a pivot axis between a first active position and a second folded-away position. The armrest includes an upper part, which in the active position is positioned with its longitudinal axis substantially parallel to a substantially vertical plane through a side surface constituting an outer edge surface of the vehicle seat and intended to support a user's forearm, and at least one lower part provided with a fixing device for attaching the upper part to the vehicle seat. The lower part includes a linking mechanism arranged for setting the upper part in a transverse direction between a first position outside the side surface and an adjustable second position, and a locking device that is arranged to activate a catch that locks the upper part in a set position after it has been moved to the second position. A vehicle seat provided with an armrest and to a vehicle including an armrest are also provided.

Abstract: A slideable armrest, which may form a lid of a vehicle console compartment, comprises a cover and a base slideably connected to each other by slideable engagement between at least one guide and at least one guide groove.

Abstract: An armrest apparatus and chair including one or more armrest apparatuses are disclosed. Each armrest apparatus includes an armrest member attached to at least one chair component. The armrest member has a first aperture and a second aperture. A first plate is positioned above the armrest member. The first plate has a longitudinal slot that is transverse to the first and second apertures. An armrest cover is attached to the first plate. A resilient device is positioned between the first plate and the armrest cover or between the first plate and the armrest member. The resilient device has a first hole sized and configured to receive the first member and a second hole sized and configured to receive the second member. A first member extends through the first aperture, first hole and the longitudinal slot and a second member extends through the second aperture, second hole and the longitudinal slot.

Abstract: The present invention provides a cost-effective, mobile, adjustable, versatile, reliable and easy-to-use exercise sitting apparatus that permits a user to develop, strengthen, stretch, increase the flexibility of and/or rehabilitate, and to eliminate or reduce pain (if present) associated with, a wide variety of muscles and/or body parts, such as the abdominal, lower back, external oblique and/or hip flexor muscles. The user of the exercise sitting apparatus may be of normal health, disabled, suffering from a disease or recovering from an illness, injury, accident or surgery. The exercise sitting apparatus comprises a platform, a turntable assembly, a slide plate assembly, a supporting structure and a base. It can be used virtually anywhere, for example, in a home, an office, a gym, a hospital, a rehabilitative facility, a back pain center, a nursing home or the like.

Abstract: An adjusting mechanism for adjusting arm rest of a chair includes an inner tube with an axial groove in an outside thereof and multiple positioning holes are located within the axial groove. An outer tube is mounted to the inner tube and an arm rest is connected to a top end of the outer tube. An engaging portion protrudes inward from an inside of the outer tube and movably engaged with the axial groove of the inner tube, so that the outer tube can be moved relative to the inner tube. An operation member is pivotably connected to the outer tube and includes a hook which extends through the outer tube and is engaged with one of the positioning holes. A guide plate is located above the hook and movably accommodated in a guide slot in the outer tube so that the operation member is operated in stable status.

Abstract: An armrest (1) for use with a vehicle seat (2), comprising a unit (3) for supporting an arm of an operator of the vehicle seated in the seat, a first fixing element (4) connected to the armrest unit (3) and a second fixing element (5) can be fastened to the seat (2) on the vehicle. The first and the second fixing element can be adjusted and locked in relation to one another by means of a device (6) for adjusting the position of the armrest unit (3) in relation to the seat when using the armrest. When using the armrest, the adjusting and locking device (6), which links the first fixing element (4) and the second fixing element (5) in at least two different positions, can be used to set the armrest unit (3) to different positions by moving the armrest unit (3) in a direction having a component in the horizontal plane, aligned so that the position of the armrest unit (3) is laterally variable in relation to the seat (2).

Abstract: The invention provides a chair armrest that is variably adjustable to allow a user to assume an ergonomically preferred sitting position. The ergonomic chair armrest comprises, either separately or together, an arm support assembly capable of adjustment to various positions through a vertical plane and an arm pad assembly capable of adjustment to various positions through a horizontal plane. The invention further provides an ergonomic chair having an armrest that is adjustable in both a vertical plane and a horizontal plane.

Abstract: A rotating structure for armrests includes a rotary plate disposed onto a support mounted to a holder extending upwardly on each of two sides of a chair. the support includes a receiving chamber formed on the top surface thereof and having a plurality of toothed recesses arranged around the external rim thereof. The rotary plate includes a pivotal member extending therefrom corresponding to the support and having a cutout fixed on one side thereof for receiving a slidable retaining tab which is biased by a spring. The the retaining tab includes a number of toothed protrusions attached thereon and engaging with the toothed recesses. The bottom of a holding panel for placing a user's elbow may be assembled with the rotary plate, thereby obtaining a quick and secure positioning purpose and preventing making noise while in operation.

Abstract: An armrest device includes an armrest mount, an armrest member coupled to and rotatable relative to the armrest mount about a pivot axis, a latch member that extends through the armrest member and into the armrest mount and that is movable in a direction parallel to the pivot axis between locking and unlocking positions, and an armrest button mounted movably on the armrest member and operable to move along a button axis transverse to the pivot axis for driving movement of the latch member from the locking position to the unlocking position. The latch member engages the armrest mount to arrest rotation of the armrest member relative to the armrest mount when in the locking position, and is disengaged from the armrest mount to permit rotation of the armrest member relative to the armrest mount when in the unlocking position.

Abstract: An office chair is provided with includes a chair arm assembly on each opposite side thereof for supporting the arms of a user. The arm assemblies each include a latching assembly to permit adjustment of the height of an arm cap thereof while maintaining the arm cap at a selected elevation. The latch assembly is engageable with an inner liner provided within a support post. Further, the armrest assembly has a plurality of interconnected and relatively movable plates which permit adjustment of the angular orientation of the arm cap along with adjustment of the arm cap in the front-to-back direction and the side-to-side direction.