US3382566A - Chair construction - Google Patents

Description

y 4, 1968 J. J. GALLA ETAL 3,382,566

CHAIR CONSTRUCTION Original Filed July 2. 1963 United States Patent 3,382,566 CHAIR CONSTRUCTIQN Joseph J. Galla and Philip J. Williams, Fairfield, Conn.,

assignors to Stewart-Warner Corporation, Chicago, 111., a corporation of Virginia Original application July 2, 1963, Ser. No. 292,268.

Divided and this application Feb. 25, 1966, Ser.

2 Claims. (Cl. 29-509) This application is a division of application Ser. No. 292,268, filed July 2, 1963, and relates to a pedestal-type chain and its construction, and more particularly, to the assembly in such type of chair of the chair post and chair lron.

A typical pedestal-type chair, such as the stenographic or executive-type ofiice 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 manumacturers or sellers prefer the first-mentioned practice, even with its disadvantages.

Several designs provide a detachable-type connection between the chair post and chair iron, such as with a third connection. However, such designs 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 thecomponents, 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 a 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:

FIG. 1 is a side elevational 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 fromline 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

FIG. 5 is a side elevational View, partially in longitudinal center section, of a typical arrangement of the components and appropriate fabricating tool members before the actual fabrication thereof.

FIG. 1 shows a typical pedestal-type posture chair 10 of the executive type. Thechair 10 includes achair pedestal 12 supported on floor surface 13 and in turn supporting vertically achair post 14 connected at its upper end tochair iron 16. Thechair iron 16 supports the chair seat 1 8 and a chair back 20.

conventionally, thechair 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 thechair seat 18. Across member 24 extends across the underside of the chair seat 13 and is connected to theopposite side members 22. Resilient spring means, such astorsion bar 26, is connected to theside members 22 and thecross member 24 in an appropriate manner to produce the desired resiliency of the chair back or chair seat relative to the chaid post.

Thechair post 14 is connected, as at 28 to thechair iron 16. Thechair post 14, threaded as at 30 and having an axially extendingkeyway 32, is connected in an appropriate manner to thechair pedestal 12 to permit height adjustment of thechair 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 Sept. 12, 1961, to S. A. Erickson et al. entitled Locking Arrangement for Swivel Chair Structure.

Thechair 10 shown is an executive-type chair wherein thechair back 20 is fixed relative to thechair seat 18. Details of construction of thechair iron 16 shown can be found in Patent No. 2,971,569, issued Feb. 14, 1961, to H. W. Parrott et al. entitled Tiltable Ofiice 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 Apr. 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 theconnection 28 including the cooperation of its various components. Thecross member 24 of thechair iron 16 has an opening 34 that receives apost support member 36. Thepost support member 36 has anintermediate shoulder 37 which bears against the lower side ofcross member 24 to support the load of the chair. Awasher element 38 is between thecross member 24 and a flattened orflared overportion 39 on thepost support member 36. Thepost support member 36 is thus confined rigidly to thecross member 24.

Thepost support member 36 is annular having a conical through-bore 4t} tapered uniformly along its length to its largest cross-dimension adjacent thechair pedestal 12. A raisedkey portion 42 extends axially of the through-bore 3 40. Thechair post 14 is tapered at itsupper end 44 to an identical conical taper angle as the through-bore 40 and is adapted to fit complementally therein. Thus, thetapered end 44 of thepost 14 is larger adjacent thechair pedestal 12 than adjacent thechair seat 18.

Theconical tapers 4t 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 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 theselflocking tapers 40 and 44. Thekey portion 42 on thepost support member 36 cooperates withkeyway 32 on thechair 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 thekey 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 thekeyway 32 into the bearing (not shown) in thepedestal 12 upon a user swivelling in the chair is minimized. The integralkey 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 difliculty by 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 thekey portion 42 is formed in thebore 40 of thepost support member 36. It can be noted in FIG. that before thepost support member 36 is secured to the chair iron, it has extending from the shoulder 37 atubular shank 52 of exterior size comparable to opening 34 ofcross member 24. The exterior of theshank 52 is knurled at 54 adjacent theshoulder 37. The shank is adapted to be press-fit into the opening 34 from the pedestal side of thecross member 24 until theshoulder 37 abuts thecross member 24.Washer 38 having anintermediate opening 55 also fits over theshank 52 and abuts thecross member 24 On the side thereof remote from theshoulder 37. It is contemplated that theflare 39 is formed by staking it over the frame member and washer. For this purpose it is desirable that thewasher 38 be of a harder material towithstand the staking operation without deforming.

FIG. 5 also shows a preferred tool arrangement for staking thepost support members 36 to thechair iron 16 and for forming thekey portion 42. Thewasher 38 is placed in a recess 58 on a frame or tool table 60, and thecross member 24 is placed over thewasher 38 onto the tool table 60. Theshank end 52 of thepost support member 36 is inserted into theopenings 34 and 55 and pressfit by means oftool 62 into thecross member 24 until theshoulder 37 abuts the cross member. In this inserted position, theshank 52 projects past theWasher 38 into abore 64 within the frame or tool table 60 which houses asecond tool member 66. The advance relative to thefirst tool member 62 of thesecond tool member 66 against the projected end ofshank 52 causes the end to be staked over thewasher 38 as at flare 39 (FIG. 3). Thesecond tool member 66 has aninner bore 68 which partially encloses the projectedend 69 of theshank 52 to cause the staking or flare 39 to occur more readily.

Thefirst tool 62 is tapered at 70 to an identical taper angle as bore 40 of thepost support member 36 and thetaper 44 on thechair post 14. The exterior surface of the taperedtool 62 has therein an axially extendedkeyway 72 which is of general size and dimension as thekeyway 32 of thechair post 14. Upon staking of thepost support member 36 to the chair iron -16 by and upon the advance of thetool members 62 and 66 toward one another, the unsupported portion of thepost support member 36 over thekeyway 72 is deformed into the keyway. This causes the previously-mentioned axially extended out-of-roundkey portion 42 on thepost support member 36. It is to be understood that thetool members 62 and 66 are of sufficiently hardened material to avoid flowing during the staking operation. After the staking operation thetool members 62 and 66 are withdrawn, and the components removed from the tool table 60.

Thus, thekey portion 42 is formed simultaneously with the staking of thepost 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. Theintegral keyway 32 andkey portion 42 preclude the loss of otherwise separate locking components which would render the connection less efiicient.

It has been determined that tapers of .6" per foot taper from approximately 4" larger cross-dimensions mating along axial lengths of 1 /2 give sufiicient holding power to secure a typical chair post-chair iron combination. A key portion raised a minimum of .005 has been found sufiicient to ensure proper positioning of the components together and to prevent rotation of them relative to oneanother.

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 combination with a chair post and a chair iron, an improved connection of securing them together formed by the steps of positioning an annular post support member through an opening in a cross member of the chair iron to project from both sides of the cross member, of staking the post support member to the cross member by means including a first tool member having its exterior surface converging conically toward its end at a small angle self-locking taper and having therein an axially formed keyway positioned within a complementary tapered although uniformly conical opening in the post sup port member and a second tool member on the opposite side of the cross member by and upon advancing the first and second tool members toward one another, effective thereby also to force at least a portion of the post support member disposed over the keyway of the first tool member into the key to cause an axially extending key portion raised from the periphery of the tapered bore of the post support member, and of removing both the first and second tool members from the chair iron, whereby a chair post member having a tapered end and axial keyway similar to the first tool member can subsequently be positioned into the bore of the post support member in proper rotational alignment with the key portion thereof and be driven against the post support member, effective thereby by means of the self-locking tapers of the members to secure them axially and non-rotatably together.

2;. The method of fabricating a planar chair iron cross member to provide a self-locking tapered surface thereon together with key means, the improvement comprising the steps of placing a post support member having a tapered bore into an aperture in said cross member, moving a first tool having an identical taper to said bore into said bore while forcing said member through said aperture until a shoulder on said support member engages said cross member adjacent one side of said aperture with said support member projecting through said aperture, moving a staking tool against the projecting end of said support member to stake said projecting end over said planar chair iron cross member to prevent disengagement of said support member from said cross member while said first tool is engaged in said bore, and the step of simultaneously forming a key in the surface of said bore during the staking of said projecting end.

References Cited UNITED STATES PATENTS Herold 297-301 Lathrop 29-469 X Hitt 28753 Hild et a1. 29509 OTHELL M. SIMPSON, Primary Examiner. 10 A. WEIDENFELD, Assistant Examiner.

Claims (1)

1. 2. THE METHOD OF FABRICATING A PLANAR CHAIR IRON CROSS MEMBER TO PROVIDE A SELF-LOCKING TAPERED SURFACE THEREON TOGETHER WITH KEY MEANS, THE IMPROVEMENT COMPRISING THE STEPS OF PLACING A POST SUPPORT MEMBER HAVING A TAPERED BORE INTO AN APERTURE IN SAID CROSS MEMBER, MOVING A FIRST TOOL HAVING AN IDENTICAL TAPER TO SAID BORE INTO SAID BORE WHILE FORCING SAID MEMBER THROUGH SAID APERATURE UNTIL A SHOULDER ON SAID SUPPORT MEMBER ENGAGES SAID CROSS MEMBER ADJACENT ONE SIDE OF SAID APERATURE WITH SAID SUPPORT MEMBER PROJECTING THROUGH SAID APERATURE, MOVING A STAKING TOOL AGAINST THE PROJECTING END OF SAID SUP-

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