US3285639A

US3285639A - Chair construction

Info

Publication number: US3285639A
Application number: US483145A
Authority: US
Inventors: Joseph J Galla; Philip J Williams
Original assignee: Stewart Warner Corp
Current assignee: Stewart Warner Corp
Priority date: 1965-08-27
Filing date: 1965-08-27
Publication date: 1966-11-15
Anticipated expiration: 1983-11-15

Description

Nov. 15, 1966 J.J. GALLA ET AL 3,285,639

CHAIR CONSTRUCTION Original Filed July 2, 1963 INVENTORS 5 I JOSfPH J. 6am

I P/l/Z m J MAL/4M5 BY fim mlwum ATTORNEY United States Patent f This is a continuation application of application Serial No. 292,268, filed July 2, 1963, now abandoned and relates to a pedestal-type chair and its construction, and

more particularly, to the assembly in such type of chair of the chair post and chair iron.

A typical pedestal-type chair, such as the stenographic or executive-type office chair, commonly includes a chair post connected at its lower end to a chair pedestal and at its upper end to a chair iron, which in turn supports the chair back and the chair seat. Frequently, these components are fabricated by a different manufacturer than the ultimate chair manufacturer or seller, so that they must be shipped to and be assembled by the latter to form the completed chair. The chair post and chair iron are particularly troublesome, since they must be connected together rigidly and with sufiicient holding capacity to support the full load of the chair.

One commonly followed practice in the chair business is that the manufacturer of the chair post and chair iron permanently secures them together such as by staking, press-fitting and pinning, or even welding; and ships them as an assembly to the chair manufacturer or seller. This type chair post-chair iron assembly generally is economical, structurally sound, and is ready for use in the chair. The assembly has. its disadvantages, however, since being considerably bulkier than the chair post and chair iron separately, it requires larger storing and shipping space; and being permanently connected, it cannot be interchanged with various other chair posts or chair irons to give different chair post-chair iron combinations.

An alternative practice is to ship the separated chair post and chair iron to the chair manufacturer or seller, who in turn, secures them together. The components being separated until used permit compact shipping and storing. However, since generally special equipment and labors are required to assemble the components properly, most chair manufacturers or sellers prefer the first-mentioned practice, even with its disadvantages.

Several designs provide a detachable-type connection 1 between the chair post and chair iron, such as with a threaded connection. However, such design-s have not been accepted commercially due primarily to their higher cost, complicated or lengthy assembly procedures, and,

lack of rigidity.

Accordingly, an object of this invention is to provide a chair post and chair iron combination which can be secured together easily and-manually without elaborate tools or time consuming labors by the chair manufacturer, seller, or ultimate user.

Another object of this invention is to provide a chair post and chair iron combination which can be assembled only according to the intended design to minimize wear of or strain on the components, and which thereafter prevent relative rotation of the components.

Another object of this invention is to provide an improved means for and method of forming or fabricating at least part of the structure to effect the previous object by and upon part of the fabrication of the chair iron itself.

In order that these as well as other objects can be more fully appreciated, reference is herein made to the following specification including as a part thereof the accompanying drawings, wherein:

ice

FIG. 1 is a side elevati-onal view of a typical executive pedestal-type chair showing the preferred embodiment of the subject invention;

FIG. 2 is an enlarged sectional view of the subject invention as seen generally from line 22 of FIG. 1;

FIG. 3 is an enlarged elevational view, partially in longitudinal center section, of the connection shown in FIG. 2;

FIG. 4 is a top plan view of the connection shown in FIG. 3; and V FIG. 5 is a side elevational view, partially in longitud-inal centersection, of a typical arrangement of the components and appropriate fabricating tool members before the actual fabrication thereof.

FIG. 1 shows a typical pedestahty'pe posture chair 10 of the executive type. The chair 10 includes a chair pedestal 12 supported on floor surface 13 and in turn supporting vertically a chair post 14 connected at its upper end to chair iron 16. The chair iron 16 supports the chair seat 18 and a chair back 20.

Conventionally, the chair iron 16 includes a pair of spaced side members 22 (only one of which is shown in FIG. 2) adapted to be connected to the underside of the chair seat 18. A cross member 24 extends across the underside of the chair seat 18 and is connected to the opposite side members 22. Resilient spring means, such as torsion bar 26, is connected to the side members 22 and the cross member 24 in an appropriate manner to produce the desired resiliency of the chair back or chair seat relative to the chair post.

The chair post 14 is connected, as at 28 to the chair iron 16. The chair post 14, threaded as at 30 and having an axially extending keyway 32, is connected in an appropriate manner to the chair pedestal 12 to permit height adjustment of the chair seat 18. A construction of the threaded connection between the chair post and the chair pedestal can be found in Patent No. 2,999,665, issued September 12, 1961, to S. A. Erickson et al. entitled Locking Arrangement for Swivel Chair Structure.

The chair 10 shown is an executive-type chair wherein the chair back 20 is fixed relative to the chair seat 18. Details of construction of the chair iron 16 shown can be found in Patent No. 2,971,569, issued February 14, 1961, to H. W. Parrott et a1. entitled Tiltable Office Chair." Chair irons, however, can also support the chair back tiltably relative to the chair seat as is shown in Patent No. 2,374,350, issued April 24, 1945, to W. F. Herold entitled Posture Chair. Accordingly, it should be understood that the particular improvement to be disclosed herein has application to any type chair post-chair iron combination.

FIGS, 2, 3 and 4 show the connection 28 including the cooperation of its various components. The cross member 24 of the chair iron 16 has an opening 34 that receives a post support member 36. The post support member 36 has an intermediate shoulder 37 which bears against the lower side of cross-member 24 to support the load of the chair. A washer element 38 is between the cross member 24and a flattened or flared ovenp-ortion 39 on the post support member 36. The post support member 36 is thus confined rigidly to the cross-member 24.

The post support member 36 is annular having a conical through-bore 4t tapered uniformly along its length to its largest cross-dimension adjacent the chair pedestal 12. A raised key portion 42 extends axially of the through-bore 40. The chair post 14 is tapered at its upper end 44 to an identical conical taper angle as the through-bore 40 and is adapted to fit complementally therein. Thus, the tapered end 44 of the post 14 is larger adjacent the chair pedestal 12 than adjacent the chair seat 18.

The conical tapers 40- and 44 are tapered at a small taper angle relative to their longitudinal center axes and engage one another on complementary axially extending surfaces. The tapers are thus self-locking or self-holding with one another. The basic requirement of a self-locking taper is that the taper causes a greater frictional force component in the direction parallel to the engaging surfaces than the force component tending to separate them. Conventionally, a self-locking taper has a taper angle varying from approximately /2" to A" per foot. See for example, the Morse, the Brown and Sharp, the Jarno, and the American Standard Machine tapers.

The chair post and the chair iron are secured together solely by means of the frictional forces developed between the complementary engaging surfaces on the self-locking tapers 4t) and 44. The key portion 42 on the post support member 36 cooperates with keyway 32 on the chair post 14 to prevent rotation of the chair iron on the chair post. Also, since this cooperation occurs in only one rotatable position of the chair post and chair iron, by properly locating the key portion 42 relative to the chair iron, strains can be minimized. For example, when key 42 is in alignment with the axis of tilt of the chair seat, as shown, any digging of the pointed edges of the keyway 32 into the bearing (not shown) in the pedestal 12 upon a user swivelling in the chair is minimized. The integral key portion 42 readily locates this proper position even for in-the-field assembly.

It should be noted that self-locking tapers can be separated from one another without too much difficulty by an impact-type blow tending to dislodge them. Thus, the top portion of the chair post, as at 47, projects slightly beyond the chair iron when assembled thereto so that a hammer (not shown) can be directed against it to separate the chair post and chair iron.

Also of particular significance in the subject invention is the manner in which they key portion 42 is formed in the bore 40 of the post support member 36. It can be noted in FIG. that before the post support member 36 is secured to the chair iron it has extending from the shoulder 37 a tubular shank 52 of exterior size comparable to opening 34 of cross-member 24. The exterior of the shank 52 is knurled at 54 adjacent the shoulder 37. The shank is adapted to be press-fit into the opening 34 from the pedestal side of the cross-member 24 until the shoulder 37 abuts the cross-member 24. Washer 38 having an intermediate opening 55 also fits over the shank 52 and abuts the cross-member 24 on the side thereof remote from the shoulder 37. It is contemplated that the flare 39 is formed by staking it over the frame member and washer. For this purpose it is desirable that the washer 38 be of a harder material to withstand the staking operation without deforming.

FIG. 5 also shows a preferred tool arrangement for staking the post support members 36 to the chair iron 16 and for forming the key portion 42. The washer 38 is placed in a recess 58 on a frame or tool table 60, and the cross-member 24 is placed over the washer 38 onto the tool table 60. The shank end 52 of the post support member 36 is inserted into the

openings

34 and 55 and press-fit by means of tool 62 into the cross-member 24 until the shoulder 37 abuts the cross-member. In this inserted position, the shank 52 projects past the washer 38 into a bore 64 within the frame or tool table 60 which houses a second tool member 66. The advance relative to the first tool member 62 of the second tool member 66 against the projected end of shank 52 causes the end to be staked over the washer 38 as at flare 39 (FIG. 3). The second tool member 66 has an inner bore 68 which partially encloses the projected end 69 of the shank 52 to cause the staking or flare 39 to occur more readily.

The first tool 62 is tapered at 70 to an identical taper angle as bore 40 of the post support member 36 and the taper 44 on the chair post 14. The exterior surface of the tapered tool 62 has therein an axially extendedkeyway 72 which is of general size and dimension as the keyway 32 of the chair post 14. Upon staking of the post support member 36 to the chair iron 16 by and upon the advance of the

tool members

62 and 66 toward one another, the unsupported portion of the post support member 36 over the keyway 72 is deformed into the keyway. This causes the previously-mentioned axially extended outof-round key portion 42 on the post support member 36. It is to be understood that the

tool members

62 and 66 are of sufliciently hardened material to avoid flowing during the staking operation. After the staking operation the

tool members

62 and 66 are withdrawn, and the components removed from the tool table 60'.

Thus, the key portion 42 is formed simultaneously with the staking of the post support member 36 to the chair iron, and is formed by distorting the normal symmetrical dimension of the through bore 40 into the through-bore. The integral keyway 32 and key portion 42 preclude the loss of otherwise separate locking components which would render the connection less efficient.

It has been determined that tapers of .6 per foot taper from approximately larger cross-dimensions mating along axial lengths of 1 /2 give sufficient holding power to secure a typical chair post-chair iron combination. A key portion raised a minimum of .005" has been found sufficient to ensure proper positioning of the components together and to prevent rotation of them relative to one another.

While only a single embodiment of the subject invention has been disclosed, it will be obvious to those skilled in the art that various other designs are possible. Accordingly, it is desired that the invention be limited only by the scope of the claims hereinafter following.

What is claimed is:

1. In a chair of the class which includes a base rotatably supporting a vertical post having a conically tapered upper free end portion concentric to its rotational axis, and a post support member fixed against axial and rotary movement on said post, said post support member having a similarly tapered conical bore receiving said free end portion of the post, sai-d post being formed with a keyway of uniform width extending axially from its free upper end toward its medial portion, the inner periphery of said post support member around said bore having an axially extending eccentric key portion equal in width to and spanning said keyway, said key portion pre senting a surface which is displaced radially inwardly with respect to the rest of said inner periphery and is located radially between an imaginary extension of said inner periphery and a plane common to the opposite edges of said keyway.

2. In combination, a chair post, a chair iron connected to the chair post, a cross member in the chair iron having an opening aligned with and open to the chair post, an annular post support .member having a cylindrical portion fitting within the opening of the cross member with a press fit, said annular post support member having a first shoulder and an intermediate shoulder, said first shoulder and said intermediate shoulder being of cross-dimension greater than the opening in the cross member, said first shoulder abutting the cross member on its upper side and the intermediate shoulder abutting the cross member on its lower side to thereby confine the post support member to the cross member, the post support member having an elongated bore aligned with and open to the chair post, said bore being conical throughout its length and diverging uniformly in the direction toward the chair post to its largest cross-dimension approximately equal to that of the chair post, thechair post and its end being tapered conically to a similar tapered angle as that of the bore of the post support member and converging uniformly in the direction to- 'ward the chair iron, the tapered end of the chair post 5 6 approximately /2 to inch per foot so as to be self- References Cited by the Examiner looking with one another, the chair post also having an UNITED STATES PATENTS axially-extended keyway in its tapered conical surface 296 017 4/1884 Jordanrecessed toward its longitudinal center axis, and a raised 2,54zj469 2/1951 Bolens 243*1881 out-of-round axially-extended key portion on the tapered 5 2 955 35 11 19 Storch 30g 23 conical peripheral surface of the bore of the post support CARL W TOMLIN, Primary Examiner. member fitting into the keyWay 1n the chair post to therev by prevent relative rotation of the chair post and post THOMAS E CALLAGHAN Examiner support member. D. W. AROLA, Assistant Examiner.

Claims

1. IN A CHAIR OF THE CLASS WHICH INCLUDES A BASE ROTATABLY SUPPORTING A VERTICAL POST HAVING A CONICALLY TAPERED UPPER FREE END PORTION CONCENTRIC TO ITS ROTATIONAL AXIS, AND A POST SUPPORT MEMBER FIXED AGAINST AXIAL AND ROTARY MOVEMENT ON SAID POST, SAID POST SUPPORT MEMBER HAVING A SIMILARLY TAPERED CONICAL BORE RECEIVING SAID FREE END PORTION OF THE POST, SAID POST BEING FORMED WITH A KEYWAY OF UNIFORM WIDTH EXTENDING AXIALLY FROM ITS FREE UPPER END TOWARD ITS MEDIAL PORTION, THE INNER PERIPHERY OF SAID POST SUPPORT MEMBER AROUND SAID BORE HAVING AN AXIALLY EXTENDING ECCENTRIC KEY PORTION EQUAL IN WIDTH TO AND SPANNING SAID KEYWAY, SAID KEY PORTION PRESENTING A SURFACE WHICH IS DISPLACED RADIALLY INWARDLY WITH RESPECT TO THE REST OF SAID INNER PERIPHERY AND IS LOCATED RADIALLY BETWEEEN AN IMAGINARY EXTENSION OF SAID INNER PERIPHERY AND A PLANE COMMON TO THE OPPOSITE EDGES OF SAID KEYWAY.