US2711787A

US2711787A - Knock-down chair

Info

Publication number: US2711787A
Application number: US224094A
Authority: US
Inventors: Jr Howard T Hallowell; Bennett Frank
Original assignee: Standard Pressed Steel Co
Current assignee: SPS Technologies LLC
Priority date: 1951-05-02
Filing date: 1951-05-02
Publication date: 1955-06-28
Anticipated expiration: 1972-06-28

Description

June 28; 1955 H. T. HALLOWELL, JR, ET AL 2,711,787

KNOCK-DOWN CHAIR Filed May 2, 1951 3 Sheets-Sheet l June 23, W55 H. T. HALLOWELL, JR, ET AL 2,711,737

KNOCK-DOWN CHAIR Filed Ma 2. 1951 s Shets-Sheet 2 22 --.Z@ A? 2 Had June W55 H. T. HALLOWELL, JR, ETAL 2,711,77

KNOCK-DOWN CHAIR Filed May 2. 1951 3 Sheets-Sheet 3 United States Patent Ofice 2,711,787 Patented June 28, 1955 KNOCK-DOWN CHAIR Howard T. Hallowell, .lr., Rydal, and Frank Bennett, Philadelphia, Pa., nssignors to Standard Pressed Steel Co., Jenlrintown, Pa., a corporation of Pennsylvania Application May 2, 1951, Serial No. 224,094

10 Elaims. (Cl. 155--=194) The present invention relates to knock-down occupational chairs, and more particularly to improved structural members for such chairs.

A principal object of the present invention is to provide a chair of the stated class of durable and rigid construction which may be shipped and stored in quantity in a minimum of space.

A further object is to provide a chair of the stated class having improved means for adjusting the vertical positions of both the seat and the backrest.

Another object is to provide a chair of the stated class having a novel friction-reducing foot element, the invention residing also in the means for securing this element to the leg structure of the chair.

A still further object is to provide a one-piece stringer or reinforcing framework for the leg members to positively position the said leg members relative to one another, thereby providing a substantial. reinforcement for the structure as a whole.

In the accompanying drawings:

Fig. l is a perspective view of a chair embodying the present invention;

Fig. 2 is an exploded perspective view of the chair illustrating the various component parts;

Fig. 3 is a front elevational view of a single leg' structure of the chair illustrated in Fig. 1;

Fig. 4 is an elevational view showing the reverse side of the leg structure illustrated in Fig. 3;

Fig. 5 is a side elevational view of the leg structure with a portion broken away to illustrate means for securing a friction-reducing foot element to the structure;

Fig. 6 is a sectional View on the line 66 of Fig. 3;

Fig. 7 is a sectional view on the line 7-7 of Fig. 5;

Fig. 8 is a fragmentary elevational view illustrating a modification in the form of the foot element within the scope of the present invention;

Fig. 9 is a perspective view of a stool embodying the present invention;

Fig. 10 is a perspective view of a structural component of the stringer or reinforcing framework for the leg members in a preliminary stage of formation;

Fig. 11 is a fragmentary view of the component illustrated in Fig. 10 in a succeeding stage of formation;

Figs. 12 and 13 are enlarged fragmentary perspective views of the corner construction of the stringer;

Fig. 14 is an exploded perspective view showing elements of the stringer;

Fig. 15 is a perspective view of a stringer embodw'ng the present invention;

Fig. 16 is an enlarged fragmentary sectional view on the line 1616 of Fig. 4; and

'Fig. 17 is a section on the line 1717 of Fig. 1.

Referring more specifically to Figs. 1 and 2 of the drawings, reference numeral 20 represents generally a knock-down occupational chair. The chair is designed to be readily broken down into its component parts for shipment and storage with other like chairs in a minimum of space. The component parts of the chair 29 include a seat structure 21 comprising in the present embodiment a circular seat element 22 with four downwardly depending upper leg members 23, a like number of lower leg members 24, arranged, as more fully set forth hereinafter, to be adjustably secured to the upper leg members 23; a one-piece stringer or leg-reinforcing frame- Worl: 26 arranged for engagement with the lower leg members 24; and a backrest 27 including downwardly depending

side pieces

28, 28 arranged to be adjustably secured to the leg members 24 by a pair of

clamps

29, 29 as more fully set forth below.

Referring to Figs. 3 to 8, the leg structure for the chair 20 comprises the. relatively adjustable upper and

lower leg members

23 and 24 respectively, each of generally angular cross section and fitted one within the other for relative sliding movement. The upper member 23 is provided with a pair of spaced

holes

31, 31 arranged to register with two of a series of regularly spaced holes 32 in the lower leg member 24, said holes being adapted for reception of fastening means in the form in the present instance of bolts 33 and associated nuts 34. This affords relative adjustment of the upper and lower leg members.

Each of the

leg members

23 and 24 is of modified angular cross section, best illustrated in Fig. 6, over the greater portion of its length. The upper member 23 comprises a pair of

side flanges

35 and 36 which lie at substantially ninety degrees to each other and are joined together at the midsection of the member by a channel 37. In effect the

flanges

35 and 36 converge. inwardly and terminate in

sidewalls

38, 38 of the channel 37, said channel comprising the said

sidewalls

38, 38 and a connecting Web 39.

The lower leg member 24 is similarly formed, having

flanges

41 and 42 which correspond to

flanges

35 and 35 of the member 23, and a central channel portion 43 which corresponds to channel 37 of member 23 having the same

relation tothe flanges

41 and 42 as does channel 37 to the

flanges

35 and 36. The upper and lower leg members differ only in the relative dimension of the parts, the channel 37 being somewhat smaller than the channel 43 so as to nest Within the latter channel as illustrated in Fig. 6.

The angular cross section of the member not only materially increases the resistance to bending and torsional stresses in the individual leg members, but also provides substantial rigidity to the adjustable interconnection of the

leg members

23 and 24, when secured by the single connecting bolt 33 and the associated nut 34. Ease of assembly is afforded not only by the use of a single nut and bolt, but also by the snug fit of the nut 34 into the channel 37 such that the

sides

38, 38 of the channel 37 embrace the sides of the nut 34 as illustrated in Fig. 6 to preclude rotation of the nut relative to the stem of the bolt as the latter is threaded into the nut. It is noted that the

apertures

31 and 32 in the

leg members

23 and 24 respectively are formed in the web portion of the

channels

37 and 43 respectively whereby flat seating surfaces are presented to the bolt and its nut to provide further structural rigidity in the interconnection.

The upper leg member 23 is flattened out at its upper terminal end as indicated at 45, the upper extremity 46 being offset inwardly from the adjoining portion of the leg member as indicated at 47 in Fig. 5. The terminal portion 46 in the present embodiment is formed transversely on the arc of a circle so as to fit the inner rim portion 48 of the circular seat 22. In the assembly of the seat structure 21, the terminal portion 46 of the leg mem-- ber 23 lies flush against the inner surface of the rim 48 by reason of the curved formation. It is noted also that the lower edge of the rim 48 will seat upon the shoulder formed at 47 by reason of the offset of the terminal portion 46. Thus when the leg member is joined to the seat 22 by welding or other suitable means, the shoulder relieves the strain on the welded union and affords further structural rigidity and durability to the seat structure 21.

The lower leg member 24, described above, is shaped at its lower extremity to form a cylindrical terminal socket 50 within which is established an anti-friction foot element As illustrated in Fig. 5 the element 51 comprises a cylindrical body portion 53 having an enlarged convex head 54 and a circumferential groove 55 encircling the cylindrical body portion 53 substantially medial of its ends. The cylindrical surface of the body portion 53 is knurled as indicated at 56 in the embodiment illustrated in Fig. 5.

In the assembly of the anti-friction foot element 51 to the lower leg member 24, the cylindrical body portion 53 fits tightly within the terminal socket of the leg member 24, the fit preferably being a force fit to afford an interlocking action between the knurls 56 and the inner surface of the cylindrical. socket 50 so as to hold the foot element 51 against rotation in the socket. Longitudinal displacement of the element from the socket is effectively precluded by pressing the metal of the wall of the socket 50 into the groove as is well illustrated in Figs. 5 and 7. In this manner the element 51 is securely anchored in the socket 50 and is effectively immobilized against movement relative to the lower leg element 24.

In some instances it has been found that the antifriction foot element may be anchored in the socket by providing the cylindrical surface of the element with cross knurls of the general type illustrated in Fig. 8 wherein the lower leg member is indicated by reference numeral 57, the socket formation by the numeral 58, and the foot element by the numeral 59. The above mentioned cross knurls, indicated at 60 afford interlocking engagement between the element 59 and the socket formation 58 to immobilize the element relative to the leg member 57.

Fig. 9 illustrates the assembly of the respective lower leg elements 24 to the seat structure 21. To provide further structural rigidity the one-piece stringer 26 is secured to the leg members near their lower extremities, as more fully described below. To this end, each lower leg member 24 is perforated at 62 (see Fig. 2) for the reception of a connecting bolt 63 and its associated nut 64.

Referring now to Figs. 10 to 16 and particularly Fig. 15 the stringer 26 comprises generally a pair of

angle members

65, 65 bent into U-shape, butted together, and integrally joined at 66, 66 as more fully described hereinafter by a pair of

connectors

67, 67.

According to the present invention each U-shaped member 65 is formed of an elongated angle member 70 illustrated in Fig. 10 comprising a horizontal flange 71 and a vertical flange 72. The flange 71 is provided with a pair of T-shaped

slot

73, 73 arranged with the enlarged head portion adjacent and parallel to the line of juncture of the

flanges

71 and 72, and the tail portion extending normal to said line of juncture the complete width of the flange 71. so as to divide the member 70 into three sections.

The central section 74 is approximately equal in length to the horizontal distance between the apertures 62 in adjacent lower leg members 24 of the assembled chair structure 20, whereas each end section 75 is equal in length to approximately one half of the said distance, such that when the member 70 is bent at the

slots

73, 73 as more fully described below, the U-shaped member 65 is formed (see Fig. 14) with the cross section 74 twice the length of each side section 75. When two such members 65,are abutted as illustrated in Fig. 15, a square framework is formed with each side equal in length to the distance be tween the apertures 62 in the assembled chair 20, thereby providing a substantial reinforcing element for the lower leg member 24 when secured thereto as described below.

Adjacent each T-slot 73 in angle member 70, the verti cal flange 72 turns outwardly to form a channel 76, as illustrated in Fig. 11. The exterior dimension of the channel 76 are such as to afford a slidable fit of said channel within the interior of the channel 43 in the lower leg member 24. The web of the channel 76 is perforated at 77, said perforation registering with the aperture 62 in the web of channel 43 so as to afford the passage of the bolt 63 through the webs of

channels

43 and 76 into engagement with the nut 64. The nut fits nicely interiorly of the channel 76, being embraced by the side walls of said channel so as to be precluded from rotation relative to the shank of the bolt 63 when the latter is threaded into the nut to secure the member 26 to the leg structure 24.

It is noted that the channel formations 76 divide the flange 72 into portions 72a and 72b comprising integral parts of

sections

74 and 75 respectively of the channel 70. The member 70 is bent as indicated by the broken lines in Fig. 11, so that the portions 72a and 72b assume a position approximately at ninety degrees to one another terminating in the side walls of channel 76 in the manner described above in connection with the formation of the

leg structures

23 and 24. To this end the terminal portions of the flange 71a in section 74 are offset upwardly at 78 to afford passage of the adjacent terminal portion of flange 71b in section 75 beneath the flange 71a, thus providing the over-lapping relationship illustrated in the drawings. To provide further rigidity to the corner formation, the overlapping terminal portions of flanges 71a and 71b are welded together as indicated at 79 in Fig. 12.

With reference to Fig. 16, it is seen that the corner structure of element 26 nests within the lower leg structure 24,

flanges

35 and 36 neatly embracing the flanges 72a and 72b respectively, whereby when the stringer 26 is secured to the leg structure 24 by the bolt 63 and its nut 64, as described above, a connection of substantial structural rigidity and durability is presented.

In the final operation in the formation of the one piece stringer 26, the U-shaped member 65 is joined to a second like member, as illustrated in Fig. 15. To this end the side sections 75 of the two members are aligned incontiguous end to end relationship at 66 to form a square framework. The connector 67 is provided, underlying the line of juncture at 66, to comprise a mutual connecting link. The sections 75 are then welded or otherwise joined to the connector 67 as indicated at 80 in Fig. 15 to provide a neat smooth junction. The horizontal flange 71 is then deflected downwardly along the inner periphery to provide further resistance to bending and torsional stresses and to enhance the ornamental appearance of the member.

A stringer of this general type affords substantial economies in manufacture and assembly. The formation of the corner in the member 70 prior to the assembly of the two members 65 enables the operator to stamp out such formations with a high degree of accuracy with a minimum of wasted time and material. The elimination of seams and joints in the corner structure improves the rigidity of such a structure, and eliminates the need for complicated jigs and fixtures in the forming operations. It is apparent that in the assembly of the chair, a single member in lieu of a multiplicity of cross pieces, provides for more efficient assembly and for a more rigid and durable end product.

Referring again to Figs. 1 and 2 and to Fig. 17, an improved adjustable backrest for a knock-down chair is illustrated. The backrest 27 is supported by the

side pieces

28, 28 which are adjustably secured to the upper leg members 23 by a pair of

clamps

29, 29. The clamp 29 is readily releasable for vertical adjustment of the back support 27, but is positive in action and non-mutilative of the chair parts with which it is immediately associated. To this end the clamp 29 consists of a split sleeve 82 adapted to embrace one of the side pieces 28, said sleeve being provided with

radial flanges

83, 83, one at each side of said split. The flanges 83 are provided with mutually aligned

apertures

84, 84, said apertures being arranged to register with the apertures 31,

in the upper leg member 23, and adapted to receive the shanks of a pair of bolts 85, 85. A nut 86 coacts with the threaded shank of each bolt 85, to contract and thereby clamp the sleeve 82 on the side piece 16,. and to secure the said side piece to the leg structure. It is noted that the nut 86 fits neatly into the channel 37, being precluded from rotation relative to said threaded shank by engagement with the

side walls

38, 38. The channel formation 43 of the lower leg member 24 affords a flat surface on which the flange 83 may seat, thus providing a high degree of rigidity and durability in the interconnection of the backrest 27 to the leg structure of the chair 20. Adjustment of the height of the backrest relative to the seat 22 is effected by loosening the bolts 85, sliding the side pieces through the sleeves to the new position, and retightening the bolts. It is apparent that the manner in which the clamps engage the side pieces of the back support obviates mutilation of the engaged elements, and thereby insures against functional deterioration.

It is apparent from the foregoing description that the present invention contemplates a knock-down occupational chair of substantial durability and rigidity. The nice fit of the individual components at each interconnection greatly facilitates the assembly of the chair; the flat interseating surfaces at each connection provides a heretofore unattainable rigidity and durability; the individual components are formed with inherent resistance to bending and torsional distortion; and the said components are simply formed such that each like element may be substituted for another like element without regard for the eventual location in the assembled chair.

In packing and storing a number of the chairs, it will be appreciated that a substantial saving in space is afforded. To this end; the seat structures 21 may be nested one within the other; the lower leg members 24, each being identical to the other, may be packed irrespective of their evenual position in the assembly; and the stringer 26 and the back supports 27 are similarly capable of packing and storing in a minimum of space.

The invention is not limited to the specific embodiments illustrated herein, but considerable modification in the structural details is possible within the scope of the present invention as defined in the appended claims.

We claim:

1. A pressed steel leg unit of angular cross sectional form, said unit comprising opposite longitudinal side flanges converging toward each other at a substantial angle and terminating in a central U-shaped channel section, said flanges adjoining the free edges of the side walls of the channed, and the baseweb of the channel forming a flat surface extending longitudinally of the unit.

2. A leg unit according to claim 1 including a framework adapted to interconnect said unit with a number of like units, said framework consisting of an elongated member having a vertical flange bent at an angle approximating the angle of convergence of said opposing flanges and formed at the apex of said bend with a channel section exteriorly dimensioned to fit snugly within the channel section of the leg unit to an extent that the web portions of the interfitted channel sections and the flanges of said sections seat nicely against each other to provide an internesting relationship, and means for securing said leg units to said framework.

3. A knock-down occupational chair comprising a seat structure consisting of a seat element and a plurality of downwardly depending upper leg members of generally angular cross section, a like number of lower leg mem bers of similar angular cross section arranged to internest with said upper leg members, means for releasably securing said leg members together in inter-nested relationship, a rigid framework disposed to interconnect said lower leg members to preclude relative movement of said members, means for releasably securing said framework to each of said lower leg members, both said upper and lower leg members comprising opposing longitudinal side flanges converging towards each other at a substantial angle and terminating in a central U-shaped channel section, said flanges adjoining the free edges of the side walls of said channel section, and the baseweb of the channel section forming a flat surface extending longitudinally of the member, and the channel section of one of said upper and lower leg members being dimensionally reduced so as to fit slidably and accurately within the channel section of the other said members.

4. A chair according to claim 3 wherein the webs of the channel portions of the respective upper and lower leg members are provided with mutually registering perforations arranged to receive said means for releasably securing said leg members together in inter-nested relationship.

5. A chair according to claim 4 including a back rest, a support for said rest having downwardly depending side pieces, and a clamp comprising a sleeve split lengthwise and partially opened to loosely embrace one of said side pieces, said sleeve being formed with radial flanges extending outwardly at each side of said split, said flanges being adapted to seat on the Web portion of the exterior channel section, and being perforated to register with the perforations in said upper and lower leg members to re ceive said securing means so that upon the tightening of said means, the sleeve is contracted about the said piece, thereby anchoring the clamp to both the side piece and the leg members.

6. A metal leg structure comprising a longitudinal member of angular cross section, the lower extremity of the said angular leg member being formed into a socket the shape of a hollow cylinder, a friction reducing foot element consisting of a cylindrical body portion dimensioned to fit neatly within said socket, an enlarged friction reducing head at the lower end of said cylindrical body, said body being inserted in said socket to an extent that the head portion of said element lies below the terminal end of the socket and being provided with a circumferential groove, and the wall of the socket being pressed locally inwardly into the groove to prevent longitudinal displacement of the foot member from the socket.

7. A leg structure according to claim 6 wherein the cylindrical body of the foot element is knurled and is force fitted into the socket to preclude rotation of said element within the socket.

8. A leg structure according to claim 7 wherein the lines of knurls on said body portion extend transversely to the cylindrical axis of the body portion.

9. A chair according to claim 3 wherein the said framework has vertical and horizontal flanges, the vertical flanges being arranged to nest against the opposing longitudinal side flanges of the leg members, and being formed at the corners with U-shaped channel sections exteriorly dimensioned to rest interiorly of the channel sections of said leg members, the free edges of the channel sections of the framework terminating in the vertical flanges of said framework, and the web of said last mentioned channels forming a flat surface to seat upon the flat web surfaces of the leg members.

10. A chair according to claim 9 wherein the respective web portions of the leg members and the framework are provided with mutually registering apertures adapted to receive the means for releasably securing said framework to the lower leg members.

References Cited in the file of this patent UNITED STATES PATENTS 102,627 Van Patten May 3, 1870 180,251 May July 25, 1876 483,174 Scoville Sept. 27, 1882 856,036 Dean June 4, 1907 (Other references on following page) UNITED STATES PATENTS 1,918,780 Rand July 18, 1933' 1,966,343 Hallowell et a1. July 10, 1934 13331322 $155,121,1 1:11:13::1'2322: 1312 2,474,668 Herbolsheimer June 28, 1949 1,286,629 Herzog Dec 3, 1918 25 O9284 Allen May 1950 1 302 359 Salomon May 6 1919 5 2, 4 ,592 OCOBHOI Feb. 27, 1951 1,467,830 Boggs Sept. 11, 1923 2,599,170 Franks J1me 1952 1,821,636 Harter $6 11. 1, 1931 2,642,121 Prick June 16, 1953 1,854,777 Bales Apr. 19, 1932