US3174795A

US3174795A - Seating structure

Info

Publication number: US3174795A
Application number: US315483A
Authority: US
Inventors: Howard D Chapman; Henry C Banke
Original assignee: CLARIN Manufacturing CO
Current assignee: Goodman Manufacturing Co LP; CLARIN Manufacturing CO
Priority date: 1963-10-11
Filing date: 1963-10-11
Publication date: 1965-03-23
Anticipated expiration: 1982-03-23

Description

March 23, 1955 H. D. CHAPMAN ETAL 3,174,795

SEATING STRUCTURE 2 Sheets-Sheet 1 Filed Oct. l1, 1965 HOW/1 @D Q CHAPMAN #EA/RVG. BAA/KE Agg March 23, 1965 H. D. CHAPMAN ETAL 3,174,795

SEATING STRUCTURE Filed oct. 11, 1965 2 Sheets-Sheet 2 United States Patent O 3,174,795 SEATING STRUCTURE Howard D. Chapman, Highland Park, and Henry C. Bauke, Chicago, Ill., assignors to Clarin Mfg. Co., Chicago, Ill., a corporation of Illinois Filed Oct. 11, 1963, Ser. No. 315,483 11 Claims. (Cl. 297-160) This invention relates to seating units. More particularly, the invention relates to seating units which include an arm assembly.

The principal object of the present invention is to provide an improved seating structure including a detachable arm assembly.

An additional object of the invention is to provide a seating arrangement which includes an aligned row of two or more seating units releasably interconnected by a detachable arm assembly supported intermediate adjacent units.

A further object of the invention is to provide an arm assembly adapted to be supported intermediate a pair of adjacent seating units and capable of interconnecting the units to each other to form an aligned row.

A still further object of the invention is to provide seating units adapted to be interconnected with one another in an aligned row and to have an arm assembly releasably attached thereto.

Another object of the invention is to provide an improved seating structure which includes a detachable tablet arm assembly.

A related object of the invention is to provide a tablet arm assembly which is adapted to be detachably mounted on a seating unit.

Other objects and advantages of the invention will become apparent with reference to the following description and the accompanying drawings.

In the drawings:

FIGURE l is 'a front elevational view of a seating arrangement showing various of the features of the invention;

FIGURE 2 is an enlarged fragmentary sectional plan view taken along line 2 2 of FIGURE l;

FIGURE 3 is an enlarged front elevational view of the tablet arm assembly which forms part of the seating arrangement shown in FIGURE l;

FIGURE 4 is an exploded fragmentary sectional view of the structure shown in FIGURE 2;

FIGURE 5 is a perspective elevational view of a seat-` ing structure showing various of the features of the invention;

FIGURE 6 is a fragmentary partially broken away plan view of a portion of the seating unit shown in FIG- URE 5;

FIGURE 7 is a fragmentary enlarged side elevational view of the seating unit shown in FIGURE 5;

FIGURE 8 is an enlarged fragmentary sectional elevational view taken along line 8 8 of FIGURE 6; and

FIGURE 9 is an enlarged sectional elevational view taken along line 9 9 of FIGURE 8.

Very generally, the illustrated embodiment of the present invention comprises an arm assembly 11 which is adapted to be detachably mounted on either or both sides of an individual seating unit 13, and which can be supported intermediate and detachably mounted on each of a pair of adjacent seating units so as to interconnect the units in an aligned row.

The seating unit 13 is in the form of a chair similar to that shown in U.S. Patent No. 3,084,977 and includes a body-receiving shell 14 supported by a pair of depending leg members 15 adjacent each of opposite sides thereof. A bracket 17 is secured to one of the pair of leg members 15, and a mating bracket 19 is secured to the "lee opposite pair. As set forth in the above-mentioned patent, these brackets are formed so as to be capable of being placed in releasable interlocking engagement with each other. Hence, when two such chairs, facing in the same direction, are arranged in side-by-side relation, they can be releasably interconnected or ganged in an aligned row.

The arm assembly 11 includes a standard 21 provided at its upper end with a generally horizontally disposed member which, in the illustrated embodiment, is in the form of a tablet arm 23 but which may assume any of various other forms, such as a conventional arm rest, if desired. The standard 21 is provided on one side with a bracket 25 similar to the bracket 19 of the seating unit 13 and capable of being placed in releasable interlocking engagement with the bracket 17 of the seating unit 13, thereby facilitating detachable mounting of the arm assembly to the seating unit in a manner which renders the tablet arm 23 suitable for use by an occupant of the seating unit. In addition, the standard 21 is provided with a bracket 27 on its opposite side, which bracket is similar to the bracket 17 of the seating unit 13 and is capable of releasable interlocking engagement with the bracket 19 of the seating unit. Accordingly, the tablet arm may be disposed intermediate, and detachably mounted on, each of a pair of like seating units arranged in side-by-side relation, thereby releasably interconnecting the seating units with one another in an aligned row.

More specifically, the bodyesupporting shell 14 is preferably molded, las from a ber reinforced resin, anddefines a seat 29 and a backrest 31, each of which may be padded as at 33 if desired. The shell 14 is attached to and supported by the leg members 15 which are defined by outwardly extending end portions of a pair of generally U-shaped

tubular members

35 and 37, which members also dene intermediate bight portions 41, referred to in greater detail shortly. The leg members 15 are tapered toward their outer ends to provide a more graceful and pleasing appearance for the chair, and each of the outer ends has detachably aixed thereto a foot 43 in the form of a universally mounted pad or button constructed to permit swivelling movement of the pad relative to the leg member to thereby ensure full supporting engagement between the pad and the supporting surface.

The bight portions 41 of the Urshaped

tubular members

35 and 37 are bent in an arcuate shape (FIGS; 5 and 6) and have a pair of horizontally spaced elongated metallic trips 45, one of which is shown in FIGURES '6 and 7, secured, as by welding or the like, to their upper surfaces. Each of the strips 4S is adapted to be detachably secured to the under-surface of the vseat 29 of the shell 14 and includes an upwardly offset ange portion 47 (FIG. 7) provided with a hole 49 at its forward end to receive a suitable fastener (not shown). An elongated slot 51 is provided in each of the strips 45 in rearwardly spaced relation to the forward ends thereof to accommodate a second fastener (not shown). The

lbrackets

17 and 19, previously referred to, render the chair 13 adapted for releasable interconnection with a-n adjacent chair and, in addition, render the chair suitable for the releasable attachment thereto of` the arm assembly 11. In addition, the'particular form of brackets shown in the illustrated embodiment serve to interconnect and brace the leg members 15 adjacent each side of the chair.

More specifically, the bracket 17 is preferably secured to the legs 15 adjacent the right side of the chair and is in the form of a trapezoidally-shaped open frame defined by generally parallel upper 4and

lower cross members

53 and 55 respectively interconnected by a pair of up'- wardly converging intermediate-sections 57. Each of s the intermediate sections includes outwardly projecting curved side flange portions 59 which are secured, as by welding, to the outer side surfaces of the leg members on the right hand side of the chair. The inner edge portions of the intermediate sections of the bracket are formed to provide oppositely facing lchannel sections 61 which are open toward the front and rear respectively of the chair and define upwardly converging grooves 63 adapted to receive complementary portions of either the bracket 19 or the bracket 25, soon to be describe-d.

The bracket 19 is iixed tothe opposite, or left hand, side of the chair 1-3 and, like the bracket 17, is in the form of a trapezoidally shaped open trame defined by generally parallel upper and lower cross members 65 .and 67 joined by upwardly converging intermediate sections 69 and secured to the leg members 15 by `curved flanges 17.' However, whereas the intermediate sections 57 of the bracket 17 are formed to provide oppositely facing channel sections 61 defining grooves 63, the intermediate sections of the bracket 19 are formed to provide a pair of inwardly facing tongues 71 which are offset outwardly of` the main plane of the bracket and are -arranged 41n upwardly converging relation to each other. The tongues 7-1 of the bracket 19 and the channels 61 of the bracket 17 are dimensioned and disposed with respect to each other such that the tongues 71 can be slidably received into the grooves 63 when the bracket l19 is rnoved downwardly with respect to the bracket 17.

' IIt will be noted in FIGURE 2 that each of the channels 61 and tongues 71 of the brackets 17 and `19 respectively define horizontally spaced, generally vertically disposed surfaces which engage one another and prevent lateral movement of the brackets relative to one another when the brackets are placed in interlocking engagement. Moreover, the converging con-figuration ot the 'channels and tongues causes them to dene upwardly and downwardly directed interengagiug surfaces respectively which limit vertical downward movement of the bracket 19 relative to the bracket 17 These features are particularly advantageous with respect to the arm assembly 11, as will become apparent shortly.

' To provide for ver-tical stacking of the chairs, a stud 73 projects outwardly from each of the leg members 15 immediately above each of the brackets 1-'7 and 19 and is engaged by the lower edge of a corresponding bracket oi a stacked overlying chair. A recess 75 -is formed in the lower edge of each of the lower cross members 55 and 67 of each of the brackets 17 and `19 to receive the studs of an underlying chair.

v Refierring now to the arm assembly 11, .the standard V21 thereof (FIGS. 3, 5 and 7) is defined by a pair of upright, horizontally-spaced forwardly and rearwardly disposed

Vtubular members

77 and 79 respectively interconnected at approximately their vertical midpoints by a horizontally extending pin 81. The pin 81 also passes through one end of a brace 83, soon to be described, which is positioned intermediate the members and is adapted for pivotal movement about the pin. A cap 85 is secured to the outer surface of the standard to conceal the open end of the brace.

The

tubular members

77 and 79 are bent so as to diverge relative to one another both above 4and below the pin 81, thereby defining a generally X-shaped configuration. The upper ends of the forwardly and rearwardly disposed

tubular members

77 and 79 are offset forwardly and rearwardly respectively to provide generally horizontally disposed

portions

87 and 89 to which the tablet arm 23 is pivotally secured, as hereinafter described;

The lower end of the standard is provided on opposite sides with the

brackets

25 and 27 which are adapted tor interlocking engagement with the

brackets

17 and 19 respectively of the chair so as to permit detachable mounting of the arm assembly 11 to a single chair 13 or to each of a pair of chairs disposed in side-by-side relation intermediate which the arm assembly is supported` The

brackets

25 and 27 also provide structural support for, and strengthen the lower end of, the standard -21 so as to prevent relative movement of the tubular membersY about the pin S1.

Mor-e specifically, the bracket 25 Vis ahixed to the innermost side of the standard so as to be adjacent to and engageable with the bracket 17 of a 'first seating unit 13a when the Iarm assembly 11 is disposed in the desired position adjacent the seating unit {lt-TIG. 1). The bracket 25 is identical to the bracket 19 and, hence, is capable of interlocking engagement with the bracket 17, thereby detachably securing the tablet arm assembly to the seating unit. 'In this regard, the bracket 25 includes a pair of inwardly facing tongues 91 which are adapted to be received in the grooves 63 of the bracket 17 when the arm assembly is lowered or moved vertically downwardly relative lto the bracket 17. Such downward movement is halted by the interengagement of the upwardly and downwardly lfacing surfaces of the channels and tongues respectively, thus providing vertical support for the assembly 11. Lateral support for the assembly is provided by the iuterengaging vertically disposed horizontally spaced surfaces of the brackets, thereby preventing or greatly limiting lateral wobbling mov-ement of the assembly.

The bracket 27 is aiixed to the opposite or outer side of the standard 21 and is therefore engageable with the bracket 19 of al second seating unit 13b disposed adjacent the iirst seating unit 13a on which the arm assembly is mounted. The bracket 27 is identical to the bracket 17 and, hence, is capable of interlocking engagement with the bracket 19, thereby detachably securing the arm assembly 11 to the second seating unit and, hence, securing the first and second seating units to one another. In this regard, the bracket 27 is provided with a pair of oppositely facing channel sections 93 defining upwardly converging grooves 95 which are adapted to receive the tongues '71 of the bracket 19 when the bracket 19 is lowered or moved downwardly relative to the bracket 27. The engagement of the arm assembly by a bracket 19 of an adjacent chair provides additional structural support for the assembly.

Accordingly, it should be apparent that the tablet arm assembly can, by vertical movement, be attached to or detached from a first seating unit 13a when the

bracket

25 and 17 are placed in, or removed from, interlocking engagement with one another, and may have a second seating unit 13b attached to or detached from it, thereby detachably securing a pair of the seating units to each other.

In order to ensure the sturdy support of the arm assembly 11 adjacent a seating unit 13a, particularly when the assembly is not receiving additional support from a second seating unit 13b, as well as to hinder the unauthorized detachment of the arm assembly, the brace S3 is provided and comprises a short tubular member (FIGS. 3 and 6) flat-tened at one end to provide a vertically disposed portion 97 which, as previously mentioned, is posi` tioned intermediate the

tubular members

77 and 79 of the standard 21. The tubular member of the brace is flattened at its opposite end to provide a horizontally disposed portion 99 which is provided with a hole to enable it to be fastened to one of the strips 45 aiixed to the bight portion 41 of the

leg members

35 and 37. In addition, a second hole isprovided at approximately the mid-portion of the brace to receive a bolt 101 from which is suspended a clamping plate 103 (FGS. 3 and 6). The clamping plate 103 is adapted to engage the lower surfaces of the bight portions 41 of the leg members 35 and 37and, accordingly is preferably provided with a pair of spaced-apart arcuate recesses (not shown).

In the'attachment of the arm assembly 11 to theseating unit 13, the outwardly extending end portion of the brace 83 is positioned intermediate the bight portions d1 of the leg members, with the'clampingplate 103 disposed in parallel relation to the brace, and with the liattened end portion 97 of the brace disposed in partially underlying relation to the strip 45. As the arm assembly is lowered to bring the

brackets

17 and 25 into engagement with one another, the brace is pivoted slightly to bring its flattened end 99 into contact with the under surface of the strip 4S. The brace is then secured to the strip 45 by a suitable fastener 195 passing through the strip 45 and end portion 99 of the brace, and the clamping plate is rotated to the position shown in FIGURE 6, after which a nut 106 of the bolt 101 is tightened to clamp the plate to the bight portions 41.

The tablet arm 23, carried on the upper end of the standard 21, may be of any conventional design but, as illustrated, comprises an elongated fiat board having an enlarged forward por-tion 107 defining a supporting surface for receiving books, writing materials, etc., and a rearwardly extending narrow neck portion 109 located along the right side of the tablet arm which is disposed farthest from the shell 14 and serves as an arm rest. The tablet arm may be formed of any rigid material, but is preferably formed of wood.

The rearward end of the neck por-tion 109 of the tablet arm is pivotally secured to the standard by means of a clip 111 aiixed to the underside of the neck and defining, with the tablet arm, a generally circular bearing cavity which receives the rearwardly directed horizontally disposed upper end portion of the tubular member 79 of the standard. The curvature of the rearwardly directed portion 89 is such that the clip 111 is unable to slide forwardly therealong and, hence, forward shifting of the tablet arm is prevented. Rearward shifting of the tablet arm is prevented by the pivotal interconnection of the forward portion of the tablet arm and the forwardly directed upper portion 37 of the tubular member 77 of the standard, as hereinafter described.

More specifically, the enlarged portion of the tablet arm has a generally L-shaped tube 113 secured by suitable fasteners 115 to its under-surface and includes an arm 117 extending generally parallel to the side edges of the tablet arm and a leg 119 extending generally transversely to the side edges.

The rearward end of the arm 117 is rotatably connected to the forward end of the horizontally disposed arm portion of the standard so as to permit the arm to be moved between a generally horizontal position, as shown in full lines in FIGURE 5, and an upright position as shown in dotted lines in FIGURE 5, the latter position facilitating ingress to and egress from the shell 14.

More specifically, the forwardly extending horizontally disposed end portion 87 of the tubular member 77 of the standard is formed to define a hollow cylindrical cavity having disposed therein a cylindrical bearing member 121 which is keyed against rotation within the cavity by a pair of pins or dowels 123 and extends outwardly of the cavity. The outer end of this extending portion of the bearing member 121 is formed to provide a projecting semi-cylindrical segment 125 having a generally vertically disposed laterally directed face 127.

The forwardly extending portion of the bearing member defines an axis about which the L-shaped tubular member 113 rotates and, in this regard, is received Within a cavity defined by the rearwardly extending ar-m 117 of the member 113. A plug 129 is disposed inwardly of the cavity of the arm and is keyed thereto by suitable pins or dowels 131. The rearwardly facing end of the plug is disposed adjacent the forward end of the bearing member 121 and is formed to provide a rearwardly projecting stud 133 of pie-shaped or quarter-round configuration adapted to cooperate with the semi-cylindrical segment 125 of the plug 121 to limit rotational movement of the tablet arm.

More specifically, and with reference to FIGURE 9, it will be seen that interengagement between the face 127 of the semi-cylindrical forwardly projecting segment 125 of the bearing member 121 and the faces of the pieshaped stud 133 of the plug 129 limits the rotation of the L-shaped tubular member 113 and, hence, of the tablet arm 23, to approximately one quarter turn, thereby permitting the tablet arm to assume either a horizontal or an upright position. It has been found preferable to form the pie-shaped stud 133 so that the included angle thereof is slightly greater than thereby placing the tablet arm at slight angles to the vertical and horizontal in each of the respective positions.

An improved seating arrangement has thus been provided which includes an arm assembly which can be detachably mounted on a single seating unit, or which can be disposed intermediate and attached to each of a pair of side-by-side units, in which case the arm assembly serves to interconnect the units to each other.

While various structural features of the invention have been shown and described with respect to one specific embodiment thereof, it should be apparent that Various modifications might be made therein without departing from the scope of the invention.

What is claimed is:

l. An arm assembly adapted to be detachably mounted adjacent one side of a seating unit to which a bracket yis iixedly secured, said arm assembly comprising a standard having affixed thereto a bracket adapted for interlocking engagement with the bracket of the seating unit, said brackets being so formed that engagement therebetween is effective to rigidly secure said arm assembly to the seating unit, and an arm member carried on said standard.

2. An arm assembly adapted to be detachably mounted intermediate a pair of seating units arranged in side-byside relation and having a bracket affixed to each of the adjacent sides thereof, said arm assembly comprising a standard having a bracket affixed to each of its opposite sides, each of said standard brackets being adapted for interlocking engagement with a complementary bracket of one of the seating units so as to detachably secure said arm assembly to each of the seating units and interconnect the seating units with each other, and an arm member carried on said standard.

3. An arm assembly adapted to be detachably mounted adjacent one side of a seating unit provided with a bracket, said arm assembly comprising a standard provided with a complementary bracket adapted for interlocking engagement with the bracket of the seating unit so as to detachably secure said arm assembly to the seating unit, said bracket of said arm assembly including horizontally spaced laterally facing surfaces adapted to cooperate with similarly disposed surfaces on the bracket of the chair to limit lateral movement of said arm assembly in the interlocking position, said bracket of said arm assembly also including a downwardly facing surface adapted to cooperate with an upwardly facing surface on the bracket of the chair to limit downward vertical movement of said arm assembly when in the interlocking position whereby said arm assembly may be lowered vertically into or raised vertically out of mounting engagement with the chair, and an arm member carried on said standard.

4. A tablet arm assembly adapted to be detachably mounted adjacent one side of a seating unit provided with a bracket, said tablet arm assembly comprising an upright standard, a complementary bracket secured to said standard and adapted for interlocking engagement with the bracket of the seating unit so as to detachably secure said tablet arm assembly to the seating unit, said standard including an outwardly extending generally horizontal member, a tablet arm disposed adjacent the upper end of said standard, and means for pivotally connecting said tablet arm to said standard comprising a support member secured to the under surface of said tablet arm in coaxial relation with the member of said standard, a bearing extending from one of said horizontal and support members in the direction of the other member, tbe other of said members defining a cavity at one'end to receive said bearing', a plug i'lxedly secured within said cavity'and including an end disposed adjacent the inwardly extending end of said bearing, said adjacent ends Of said bearing and said plug being provided with meshing projections to limit rotation of said support member and, hence, of said tablet arm to a predetermined included angle.

5. A seating arrangement comprising a seating unit having a bracket allixed adjacent one side thereof, and an arm assembly detachably mounted on said seating unit, said arm assembly comprising a standard, a bracket atxed to said standard and interlockingly engaged with said bracket of said seating unit, said brackets being so formed that engagement therebetween is effective to rigidly secure said arm assembly to the seating unit, and an arm member carried on said standard.

Y 6. A seating arrangement comprising a seating unit, a bracket secured to said seating unit and dening a pair of horizontally spaced'laterally facingy surfaces and an upwardly facing surface, andan arm assembly detachably mounted on said seating unit, said arm assembly comprising a standard, a bracket secured to said standard, said bracket defining a pair of horizontally spaced laterally facing surfaces and a downwardly facing surface in engagement with said laterally and upwardly facing surfaces respectively deiined by said bracket secured to said seating unit, and an arm member carried on said standard.

7. A seating arrangement comprising` a seating unit, a bracket secured to said seating unit, said bracket including a pair of channels deiining upwardly converging grooves, and an arm assembly detachably mounted on said seating unit, said arm assembly comprising a standard, a bracket securedto said standard, said bracket including a pair of upwardly converging tongues disposed within the said grooves defined by said bracket of said seating unit, and an arm member carried on said standard.

8. A seating arrangement comprising a seating unit provided with a bracket, and a tablet arm assembly detachably mounted on said seating unit, said tablet arm assembly comprising a standard, a bracket secured to said standard and interlockingly engaged with said bracket or' said seating unit, said standard including an outwardly extending generally horizontal member, a tablet arm disposed adjacent the upper end of said standard, and means for pivotally connecting said tablet arm to said standard comprising a support member secured to the under surace yof said tablet arm in coaxial relation with the member of said standard, a bearing member extending from one of said horizontal and support members inthe direction othe other member, the other of said members defining a cavity at one end to receive said bearing, a plug xedly secured within said cavity and including an end disposed adjacent the inwardly extending end of said bearing, said adjacent ends of said bearing and said plug being provided with meshing projections to limit rotation of said support member and, hence, oli said tablet arm to a predetermined included angle.

9. A seating arrangement comprising a pair of seating units disposed in side-by-side relation, a rst and a second bracket secured to cach of opposite sides of each of said seating units, said rst bracket including a pair ot channels defining upwardly converging bracket including a pair of upwardly converging tongues, and an arm assembly disposed intermediate said seating units and detachably secured to each so as to detachably secure said seating units to each other, said arm assembly comprising a standard, a rst and a second bracket secured to opposite sides of said standard and interlockingly engaged with a bracket `of one of said side-by-side seating units, said lirst bracket including a pair of upwardly converging tongues disposed within the said upwardly converging grooves of said rst bracket of said seating unit and said second bracket including a pair of channels deiining upwardly converging grooves having disposed therein the tongues of said second bracket of said seating unit, and an arm member carried on said standard.

it). A seating arrangement comprising a pair of seating units disposed in side-by-side relation, a bracket secured to each of opposite sides of each of said seating units, one of said brackets dening a pair of horizontally spaced laterally facing surfaces and a downwardly facing surface, and an arm assembly disposed intermediate said seating units and detachably secured to each so as to detachably secure said seating units to each other, said arm assembly comprising a standard, a bracket secured to each of opposite sides of said standard and interlockingly engaged with a bracket of one of said side-by-side seating units, one of said brackets defining a pair of horizontally spaced laterally facing surfaces and a downwardly facing surface in engagement with said laterally and upwardly facing surfaces respectively dened by said one bracket of said seating unit, and an arm member carried on said standard.

ll. A seating arrangement comprising a pair of seating units disposed in side-by-side relation, a bracket secured to each of opposite sides of each of said seating units, one or said brackets including a pair oi' channels deiining upwardly converging grooves and the other of said brackets including a pair of upwardly converging tongues, and an arm assembly disposed intermediate said seating units and detachably secured to each so as to detachably secure said seating units to each other, said arm assembly comprising a standard, a bracket secured to each of opposite sides of said standard and interlockingly engaged with a bracket of one of said side-by-side seating units, one of said brackets including a pair of upwardly converging tongues disposed within the said upwardly converging grooves of said one bracket of said seating unit and the other of said brackets including a pair of channels defining upwardly converging grooves having disposed therein the tongues of said other bracket of said seating unit, and an arm member carried on said standard.

References Cited by the Examiner UNTED STATES `PATENTS 3,684,977 4/ 63 Chapman 297-239 3,095,236 6/63 Klassen 297-162 FOREIGN PATENTS 822,162 12/37 France.

560,270 9/57 Belgium.

806,377 12/58 Great Britain. 1,062,407 7/59 Germany.

862,789 3/6l Great Britain.

FRANK B. SHERRY, Primary Examiner.

grooves and said second

Claims

1. AN ARM ASSEMBLY ADAPTED TO BE DETACHABLY MOUNTED ADJACENT ONE SIDE OF A SEATING UNIT TO WHICH A BRACKET IS FIXEDLY SECURED, SAID ARM ASSEMBLY COMPRISING A STANDARD HAVING AFFIXED THERETO A BRACKET ADAPTED FOR INTERLOCKING ENGAGEMENT WITH THE BRACKET OF THE SEALING UNIT, SAID BRACKETS BEING SO FORMED THAT ENGAGEMENT THEREBETWEEN IS EFFECTIVE TO RIGIDLY SECURE SAID ARM ASSEMBLY TO THE SEATING UNIT, AND AN ARM MEMBER CARRIED ON SAID STANDARD.