US1437875A - Back support - Google Patents

Description

C. J. TRAVERS.

BACK SUPPORT. PPLICATIQN FILED NOV. 8,1921.

Lgysmo Patented Dec. 5,1922.

2 SHEETS-SHEET l.

C. J. TRAVERS.

BACK SUPPORT. APPLICATION FILED I'Iov. a, 1921.

Patented Dec. 922

2 SH EETS-S 2.

Patented Dec. 5, 1922.v

NITED STATES I 1,437,875 PATENT OFFICE.

CHARLES J'. TRAVERS, OF PORT WASHINGTON, WISCONSIN, ASSIGNOR T0 GILSON MFG. CO., OF PORT WASHINGTON, WISCONSIN.

BACK SUPPORT.

Application filed November 8, 1921. Serial No. 513,702.

, To all whomz't may concern:

Be it known that I, CHARLES J. TRAVERS, a citizen of the UnitedStates, and resident of Port Washington, in the county of Ozaukee and State of Wisconsin, have invented certain new and useful Improvements in Back Supports; and I do hereby declare that the following is a full, clear, and exact description thereof.

My invention refers to chair iron fittings` and particularl to fittings for the general type of typewriter chairs wherein the back support is adjustable and yieldable, relative to tlie'seat support. Heretofore the usual practice has been to provide some direct pivot connection between the back support and the fitting, whereby the back support is adjusted horizontally and the means for locking said back support in its adjusted position has either been in a form of a fixed selective adjustment 0r the adjustment has been effected by friction. The result of these types of radial adjustments has demonstrated in practice that, due to wear, slippage -will occur in the friction types mentioned, whereby accidents may happen when the weight of the chair occupant is put upon the back rest. In cases where the adjustment is limited to a series of fixed positions, the scope of adjustment is not sufficient to meet all of the requirements.

My invention therefore, vprimarily contemplates advancing the art, wherein the objectionable features mentioned above are overcome by a simple, economical and effective means, which means can be manufactured at a minimum cost to thus insure micromic horizontal adjustment of the back support.

Referring again to the prior art. structures, provision was made for adjusting the height of the back support, in which case the shoulder pad in connection with seats of this general type was raised or lowered with relation to the back support or arm by some means. Hence in effecting the adjustment of the shoulder rest, in a vertical direction, requires more or less time and skill for raising or lowering the shoulder pad and locking it in connection with lthe supporting arm.

In addition to the objectionable features mentioned, it is necessary in some cases to drop the pad below the upper end of the arm, so that the device appeared unsightly.

Furthermore, the locking means added to the expense in manufacture and when in the form of a wing nut or analogous device, this nut forms an unsightly projection and frequently causes accidents to the persons using the chairs due to coming in contact therewith.

My invention, therefore, contemplates overcoming these objectionable features by employing a single fitting or shoe, having means in connection therewith for adjusting the back supporting arm radially, and also for adjusting it vertically. The vertical adjustment is effected by friction means which is suiiicient to resist all strain for this particular adjustment, due to the fact that the load strain upon the back support or arm is at a right angle to the clamping strain.

The main object of my invention, therefore, is to provide a simple, economical and durable fitting for effecting vertical and horizontal adjustment of the back support, at a common point, together with locking means for preventing slippage after such vertical adjustment.

Other objects of my invention are:

To provide a master shoe. with mea-ns for effecting michromic vertical and horizontal adjustments of the back support, each adj ustment being directly associated with the shoe.

To provide a pivoted master shoe with friction means for effecting vertical adjustment of the back support and positive screw means for producing the desired horizontal adjustment, whereby the position of the back pad may be micromically set and locked, the back pad being a fixture with relation to the upper portion of the arm.

To-provide a hanger of the spring controlled link type associated with a seat supporting chair iron, the link having pivoted to its rocking end, a back supporting shoe with a screw adjusting means connecting the shoe and link, whereby the back support is positively adjusted about the shoe axis, together with means for guiding and adjusting the lower end of the back support with relation to the shoe, whereby the pad is raised or lowered bodily with the arm thereof and locked in such vertical adjustment by friction means.

To provide the previously mentioned back supporting shoe with side fianges between which the back supporting arm is fitted, whereby a single retaining bolt will confine the arm in proper vertical alignments and in its various adjusted positions.

To provide a clamping bolt for the arm which is raised and lowered with said arm and confined in a slot in the retaining shoe.

To provide various structural features in connection with the shoe and pivoted link associated therewith, whereby these parts are manufactured' at a minimum cost and tures of my invention, the section being indicated partly by line 1-1 of Figure 2.

Figure 2, an enlarged fragmentary bottom plan vie'w of the back supporting adjustment fittings with parts broken away and in section to more clearly illustrate certain structural features.

Figure 3, an enlarged cross sectionalview through the back supporting arm and pad. showing particularly the permanent means for attaching the pad to the arm, whereby these parts are held securely metal to metal. and the fastening means concealed.

Figure 4, a detailed sectional elevation through the adjustment fittings of the seat support, the section being indicated by line 4 4 of Figure 1.

Referring by characters to the drawings, A represents a chair spider of standard type, having a trunnion 1, which serves as a pivot support for a link 2. The link is provided with a depending apertured arm 2 through which is extended a spring retaining bolt a, which bolt passes through a web of the spider A, and is provided with collars or thimbles between which a coil spring is mounted and adjustably tensioned by a knurled hand wheel c, the same being in threaded union with the end of the bolt rz. The arm 2 of the link 2 is normally held under spring tension against the inner'face of the spider web, as shown. whereby movement in one direction of the link is limited. it being understood that the link has free movement in opposition to its spring control upon the pivot trunnion 1 whereby the back rest, to be hereinafter described, is capable of yielding under horizontal strain about its axis or trunnion 1 upon which it is primarily mounted. Hence the link 2 or leg is, in

effect, oscillatory and the side bars thereof, as shown, are cross connected by the arm 2 and companion webs 3 3', which structure of link materially increases its strength in proportion to the weight of the metal, it being borne in mind that this link or leg carries the load strain incidentally developed by the weight of the occupant upon the back rest.

The rear free end of the link is formed with apertured ears 2 for the reception of a pivot stud 4, which stud is upset or otherwise secured to ears 5 of an oscillatory shoe 6. The base 6 of the shoe has also extending therefrom, companion lugs 7, which lugs are cross connected by a pivot pin 7 that also passes through the shank of a screw threaded stem 8. The stem extends through a clearance slot 8 that it formed in the rear web 3 of the link and said stem also extends through and is supported by an aperture 8 which is aligned with the aforesaid slot and is formed in the opposite companion web 3 of the pair, as best shown in Figure 1. The parallel web 3 and 3 of the link are spaced apart a sufficient distance to permit free rotation therebetween of an adjusting wheel or nut 9, the same being in threaded union with the stem 8.

As best shown in Figure 2, the adjusting nut 9 is knurled for hand manipulation and mounted between the rear face of the same and the juxtaposed wall of the web 3, is a coil spring washer 9. which washer in connection with the hub ot' the wheel normally fills up the gap between the webs and locks the nut against rotation after it is manually operated for adjusting purposes, it being understood that the knurled face of nut or wheel extends a sufficient distance below the link webs whereby access may be had thereto. The spring washer 9 also urges the nut against the face of the web 3 and serves as a take-up to prevent play or rattle of the stem 8 incidental to movement of the shoe upon its pivot 4.

As best shown in Figure 1, the shoe 6 is preferably rectangular in form and its rear face has extended therefrom, parallel flanges 10, between which flanges is fitted the lower end lever 11 of a back supporting post or arm 11, the same being preferably shaped up from a wooden strip. The arm is clamped to the base of the shoe 6 bya bolt 12, the squared shank of which boltpasses through a centrally positioned slot 10 formed in the shoe base. The bolt extends through an aperture bored in the lower end 11 of the arm, and said bolt is in threaded connection with a knurled hand wheel or nut 12. The base of the shoe is of such length, in proportion to the enlarged base of the lower end of the arm 11. that said arm can be adjusted vertically within the scope of the slot 10 and frictionally locked in its adjusted position to insure a full supported surface between the base and shoe flanges with relation to the arm end, whereby both vertical and horizontal strain is effectually resisted. Thus it will be seen that the arm and shoe connection involves primarily a single bolt, whereby these parts may be adjusted with relation to each other in a vertical direction, and whereby they are frictionally held against slippage and also against side movement, due to the shoe flanges. This vertical adjustment is for the purpose of positioningthe back pad 13, that is connected to the upper end of the arm, with relation to the back and shoulders 'of the occupant of the chair, whereby the rest will provide the desired comfort and support.

Radial or horizontal adjustment of the back pad 13 with relation to the seat, is micromically effected by rotation of the hand wheel 9 and its associated stem and other parts, whereby the shoe 6 is rocked upon its trunnion or axis 4, back or forth, and when the desired adjustment is effected to the convenience and taste of the chair occupant, there is no liability of this positive adjustment being disarranged. due to the threaded stern and wheel connection which are locked firmly in conjunction with the spring washer. Hence a positive horizontal adjust-ment of the back rest is obtained solely through metallic connections to insure locking of the parts. V

Obviously I may, without departing from the spirit of the invention, employ mechanical equivalents for the wheel and threaded stem, that is, any cam mechanism properly designed will produce the desired positive adjustment and lock.

Attention is further called to the fact that the vertical adjust-ment of the back rest is tangential with relation to the axis of the oscillatory arm 2, and owing to this fact, there is no strain in a vertical direction of these parts, after they are adjusted. Hence friction means can be employed to produce the desired practical results.

It will be further noted that the vertical adjustment of the back rest is effected from the base of the arm and closely associated with the horizontal adjustment thereof. Therefore it is not necessary to shift the position of the pad 13'so as to lengthen or shorten the back rest. Hence the upper end of the arm and its associated back pad 13, in the development of my invention, can be permanently secured together to present a neat appearance and to avoid radial play of the parts due to wea-r.

Referring particularly to the back rest, as shown in Figures 1 and 3, the rear wall of the shoulder pad 13 has secured thereto, a hollow rectangular metallic shell 14 by means of wood screws 14', the heads of which wood screws are counter sunk with relation to the outer face of the shell. -The base wall of the shell is also formed with a pair of centrally positioned spaced apertures, which apertures are aligned with counter-sunk apertures 15 that are formed in the back wall of the shoulder pad 13, the same being preferably composed of wood. The outer shoulders of the apertures 15 constitute seats 15 for nuts 16, which nuts are inserted between the juxtaposed walls of the pad and shell, prior to the shell being permanently secured to said pad. The nuts thus constitute clamping members which are in threaded engagement with retaining screws 17 that pass through the arm apertures, their heads being counter sunk therein, whereby plugs may be inserted thereover to present a finished and neat appearance when the structure is completed.

Thus all retaining elements between the pad and upper end of the arm are concealed, and at the same time, these retaining elements are secured by metal to metal contacting parts.

While I have shown and described one exemplification of my invention minutely as to detail, it is understood that may vary the structural features within the scope of the claims as they may be hereinafter interpreted by those skilled in the mechanical art.

For example the hanger or link Q'may, in some instances, be rigidly connected to the chair arm or seat, whereby the yielding movement thereof upon the pivot 1 is dispensed with.

l claim:

1. An adjustable back support for chairs comprising a chair spider, a. hanger pivoted thereon, resilient means opposing the movement of said hanger in one direction, a back supporting shoe, a pivot carried by said hanger, said shoe being rotatable on said pivot and a nut and screw controlled adjusting means connecting the shoe and hanger operable to gradually alter the adjustment on the mere rotation of said nut.

2. In a chair having a spider, a link in pivotal union therewith, having` an arm, a bolt carried by the spider having a spring engageable with the arm. whereby yield of the. link in one direction is had, the combination of a shoe in pivotal union with the outer end of the link, the base of the shoe being longitudinally slotted, a web extending from the link, a threaded stem carried by the shoe and extending through the web. an adjusting wheel engageable with the web and in threaded union with the stem. means for holding the adjusted wheel against longitudinal movement with relation to the stem, a back supporting arm mounted upon the shoe, and a bolt carried by the arm having its head mounted in the shoe slot for adjusting and locking the arm upwardly or downwardly with relation to the shoe slot.

3. A horizontally yieldable back support comprising a seat support, a spring controlled link in pivotal uniontherewith, said link having at its free end companion webs, a shoe having forwardly extended ears in pivotal union with the free end of the link, a threaded stem carried by the shoe and extending towards the link webs, a wheel mounted between the link webs in threaded union with the stem, flanges extending rearwardly from the shoe and a back supporting arm adjustably mounted upon the shoe between the flange.

I. A horizontally yieldable back support comprising a seat support, a spring controlled link in pivotal union therewith, a

' shoe having a fiat slotted base and ears extending therefrom, pivot means connecting the ears and free end of the link, a threaded stem extending from the base of the shoe, a web carried by the link, a wheel in threaded union with the stem associated with said web, means for confining the wheel against longitudinal play with relation to the stem, whereby the wheel, when rotated, will cause the shoe to oscillate upon its pivot connection with the link, a back supporting arm fitted -to the base of the shoe, means for adjusting and clamping the back supporting arm to the base of the shoe, and means for locking the arm against radial play with relation to the shoe.

In a horizontally yielding back support, a link, a shoe in pivotal union therewith, the lshoe including a base, ears extending forwardly from the base for effecting a pivotal connection with the link, parallel flanges extending rearwardly from the shoe base adapted to receive therebetween the lower end of a back supporting arm, a slot being provided in said base for the recep tion of' a clamping screw for said arm, and a threaded stem and nut connection between the shoe and link, whereby said shoe is moved about its pivot point.

6. A back support comprising a pad, a metallic shell secured to the rear face of the pad, nuts encased within the shell between the rear face of the pad and opposite face of said shell, an arm and a pair of set screws for the pad extending through said arm in threaded union with the nuts.

In testimony that I claim the foregoing I have hereunto set my hand at Milwaukee in the county of Milwaukee and State f Wisconsin.

CHARLES J. TRAVERS.

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