US2093319A - Posture chair - Google Patents

Description

sept. 14,1937. WF1-15mm 2,093,319

POSTURE CHAIR' Filed July 50, 1936 2 Sheets-Sheet l INVENTOR WALTER 1T- HEHULD.

BY 11ML va/64M- ATTORNEY Sept. 14, 1937. W, F HEROLD 2,093,319

POSTURE CHAIR Filed July 30, 1936 2 Sheets- Sheet 2 l .INVENTO WALTER FHERULD.

BY l

ATTORNEY Patented Sept. 14, 1937 UNITEDy STATES Partnr orties i POSTURE CHAIR Application July 30, 1936, Serial No. 93,351

5 Claims.

The present invention relates to an improvement in posture chair, particularly of the type in which the chair back is tiltably supported and is adapted to be adjusted as to angularity, height,

5 and tension, for the purpose of adapting the back to the particular person using the chair.

The present improvement relates especially to the means for adjusting the angle of the chair back, an object being to provide such means l which will be of simple and sturdy construction, which will reliably support the back in adjusted position without slippage, and which may be easi- 1y and conveniently operated to adjust the angularity. To this end it is proposed to provide slots 15 in the tilting member which cooperate with slots inthe angle adjusting back supporting member pivotally secured/to the tilting member, these slots being engaged by a shaft, and being arranged in such angular relation to each other 20 that the shaft is frictionally engaged by the slots with a scissors-like gripping action, which while permitting convenient angular adjustment of the l back'in the unsecured relation :of the shaft will rigidly support the back against movement upon 25naxial tightening of the shaft.

Due tothe scissors-like gripping action of the slots upon the-shaftonlya relatively slight axial frictionis requiredin the securing vof the shaft, so that the latter may be secured by a compara- 30gtively-easy and 'slightturning of the hand nut onthe end of theshaft, asdistinguished from certain previous types of' angle adjusting means in which the shaft engaged slotted means but in which the whole securing action depended upon 35;#.the -axialtightening of the shaft, or upon axially engaged interlocking means, asteeth or the like.

Withwthe above and other'objects in view an embodiment oft-the invention is shown in the accompanying drawings, and this embodiment will 4#-fbe hereinafter more fully described with Vreference;.thereto,and theinvention will be finally pointed out in the claims.

In the drawings:

Fig. l is aside elevation offa chair `back tilting 45.rf-mechanism, according to the invention, the chair baseand--theupper portion of the chair back `ig.3lis a transverse verticallsectional View takenalong-the line23--3 of Fig. 2.

Fig.4 isa, side e1evationenlarged, of the tilting member Vandthe angle adjusting member, show- 55-- glng.in,.full. lines one position of adjustment, and

showing in dot-and-dash lines two other positions of adjustment.

Similar reference characters indicate corresponding parts throughout the several figures of the drawings.

Referring to the drawings, the chair seat lil has secured to its under side a pair of angle iron spider arms H-ll between which there is clisposed a bearing post'member l2, the side portions l--l of which are secured to the respective inner sides of the spider arms by means of rivets I4.

The tilting member, preferably formed of sheet metal, is mounted for tilting movement upon the bearing member l2, and comprises an upper transverse portion i5 and side portions lit-l bent downwardly at right angles therefrom, the side portions extending rearwardly beyond the rearward edge of the upper portion and being provided at their rearward upper corners with apertured bearing portions El for pivotally mounting the angle adjustment member, hereinafter more fully referred to. The tilting member is mounted for tilting movement at the forward lower corners of the side portions by means of a bolt I8 engaged through apertured bearing lugs |9-I9 formed upon the bearing post I2, the sidesv lS-IE being disposed between these bearinglugs l9-I9 and the side portions l3-l3 of the bearing post.

The sides IB-IS are provided with outwardly embossed stop portions 2!! and 2l between which are disposed the inner head ends of the rearwardly disposed rivets lffl, and which head ends act as limit stops for determining the range of tilting movement of the tilting member, the stop portions 2l being engaged with the rivet heads in the non-tilted position, and the stop portions 20 engaging the rivet heads in the fully tilted position.

In the upper transverse portion I5 there is provided near the forward edge an opening 22 from the rearward edge of which there is bent upwardly a flange 23 having a slot 2li therein, which slot also extends rearwardly in the top portion l5, the rearward surface of the flange 23 at each side of the slot 24 forming with the upper surface of the top portion I5 V-shaped pockets in which are engaged the knife edge portions 25-25 of the head 26 provided upon the end of the spring bolt 2l.

The bolt 21 extends forwardly at a downward angle through the opening 22 and through an opening 28 provided in a vertically disposed bearing wall .portion 29 of the bearing post member adjusting member.

l2, this portion 29 being integrally formed with and extending between the side portions |3-I3 of the bearing member. At the forward side of the bearing wall 29 there is formed an annular groove 30 in which is seated one end of the spring 3|, the other end of the spring being engaged by a washer 32, the groove 35i being provided with a shoulder 33 and the washer 32 being provided with a shoulder 34, which shoulders are respectively engaged by the ends of the spring. The forward end of the bolt 2l is threaded and projects loosely through the washer 32 Where it is engaged by an internally threaded hand Wheel or nut 35, which upon being turned adjusts the tension of the spring. The spring normally maintains the tilting member I6 and the back supported thereby in non-tilted position with the stops 2| in engagement with the rivet heads I4. Upon rearward pressure being applied to the chair back the tilting member swings downwardly to the point where the stops 20 engage the rivet heads, the spring becoming compressed and returning the chair back tol non-,tilted position upon release of rearward pressure thereon.

A yoke shaped angle adjusting member comprising side portions 36-36 having a connecting portion 3l is pivotally mounted upon the tilting member by means of a shaft 38 engaged in the bearing portions I'l-I'l of the tilting member and in inwardly embossed bearing portions 39--39 provided upon the upper ends of the sides 36-36. The corners between the side portions and the connecting portion of the angle adjusting member are preferably of bevelled form, as at 1U-40, the portion 31 being engaged by the intermediate channel portion ll-4| of the lower strap portion 42 of the chair back, this strap portion carrying at its ends the tubular uprights 43-43 upon the upper ends of which the upper portion of the back is'secured.

The member 42 is mounted for vertical adjustment by means of a headed bolt 44 engaged through a, vertical slot 45 in the portion 31 of the angle adjusting member and through an aperture 46 in the channel portion 4|, a hand wheel or nut 41 being engaged upon the bolt at the rearward side of the portion 4|. Upon loosening of this nut the back may be adjusted as to height upon the angle adjustment member, the adjustment being secured by tightening of the nut.

VIn each side I6 of the tilting member there is provided an elongated inclined slightly arcuate slot 48 and in each side 36 of the angle adjusting member in an inwardly embossed bearing portion 4g thereof there is provided an inclined slot 55 disposed in intersecting angular relation to the slot 48 of the tilting member. A bolt 5| is engaged through the slots 48 and 50, being provided upon one end with ahead 52 engaged With the outer surface of the bearing portion 49 of one of the sides 36 of the angle adjusting member and provided adjacent this head with a squared portion 53 engaged in the slot 50 of the same side of the angle adjusting member to prevent rotation of the shaft relative to the angle A Spanner sleeve 54 is engaged upon the shaft between the sides |6|S of the tilting member having frictional engagement at its ends with the inner surfaces of said sides adjacent the slots 48. Another sleeve 55 is engaged upon the shaft between the hand wheel or nut 56 provided upon its threaded end and the side 35 of the angle adjusting member opposed to the side engaged by the bolt head 52. Upon turning of the nut 56 a clamping action is set up between the head 52 and the sleeves 54 and 55 axially of the bolt, which' frictionally binds or clamps the sides of the tilting member and the angle adjusting member together.

The angular arrangement of the slots 48 and 50 with respect to each other is such that a scissors-like binding action is set up upon the bolt 5| producing a moment of .resistance against relative movement between the tilting member and the angle adjusting member, which in addition to the binding action set up upon tightening of the nut 56 rigidly secures the parts against movement. The arrangement of the double slots is such, when pressure is applied against the back in the tightened or locked relation of the parts, that the axial clamping action only takes a portion of the torque or moment around the axis of the pivot shaft 38, the resultant being taken by the shearing action between the slots rand the bolt. As only a slight axial clamping action is required to prevent relative movement of the bolt in the slots, the nut 58 does not have binding action there is, as the back isadjusted v forwardly or rearwardly, a camming action set up between the slots 48 and 5|)` andthe bolt causing the bolt to move in one or the other direction in the slots.

I have illustrated and described a preferred and satisfactory embodiment of the invention,

but it will be obvious that changes may be made therein, within the spirit and scope thereof, as dened in the appended claims.V

Having thus described my invention What I claim and desire to secure by Letters Patent isz- 'f point of engagement of said restraining means that they are adapted upon application of manual turning force to said angle adjusting member to exert both a shearing and a propelling force to move said restraining means when loose; in said slots throughout the range of its motion, and adjustable means cooperating with said restraining means to exert a force thereon opposite to and at least equal rto said propelling force whereby said slots are effective to exert only sheering action on said restraining means through said application of force to said angleV adjusting means. Y

2. Angle adjusting means comprising va supporting member, an angle adjustingmember pivoted to said supporting member, each of said members having a slot, the 'slot of` one member being at an angle to and intersecting the slot of the other member and both of said slots being'` non-concentric to the pivot axis, restraining means movably engaged in the yintersection of said slots, one of said slots being so curved that they are at a substantially constant angular relation at the point of engagement of said 'restraining means, said slots adapted uponiapplication of manual turning force to said angle adjusting member to exert both a sheering and a propelling force to move said restraining means When loose in said slots, throughout the range of its motion, and adjustable means cooperating with said restraining means to exert a force thereon opposite to and at least equal to said propelling force whereby said slots are effective to exert only sheering action on said restraining means through said application of force to said angle adjusting means.

3. Angle adjusting means comprising a supporting member, an angle adjusting member pivoted to said supporting member, each of said members having a slot, the slot of o-ne member being at an angle to and intersecting the slot of the other member and both of said slots being non-concentric to the pivot axis, restraining means movably engaged in the intersection of said slots, one of said slots being straight and one of said slots being so curved that they are at a substantially constant angular relation at the point of engagement of said restraining means, said slots adapted upon application of manual turning force to said angle adjusting member to exert both a sheering and a propelling force to move said restraining means When loose in said slots, throughout the range of its motion, and adjustable means cooperating with said restraining means to exert al force thereon opposite to and at least equal to said propelling force Whereby sai-d slots are eiective to exert only sheering action on said restraining means through said application of force to said angle adjusting means.

4. Angle adjusting means comprising a supporting member, an angle adjusting member pivoted to said supporting member, each of said members having a slot, the slot of one member being at an angle to and intersecting the slot of the other member and both of said slots being non-co-ncentric to the pivot axis, restraining means movably engaged in the intersection of said slots, said slots being so shaped that they are constantly at such angular relation at the point of engagement of said restraining means that they are adapted upon application of manual turning force to said angle adjusting mem' ber to exert both a sheering and a propelling force to move said restraining means When loose in said slots, throughout the range of its motion, and adjustable means cooperating with said restraining means to exert a force thereon opposite to and at least equal to said propelling force whereby said slots are effective to exert only sheering action on said restraining means through said application of force to said angle adjusting means, said restraining means being slidably and non-rotatably engaged in one of said slots.

5. Angle adjusting means comprising a supporting member, having a pair of spaced side portions, an angle adjusting member having a pair of spaced side portions and pivoted to said supporting member, each of said side portions of said members having a slot, the slots of one member being at an angle to and intersecting the slots of the other member and the slots of both members being non-concentric to the pivot axis, a single bolt extending between said side portions and engaged near its ends in the intersections of said slots, said slots being so shaped that they are constantly at such angular relation at the point of engagement of said bolt that they are adapted upon application of manual turning force to said angle adjusting member to exert both a sheering and a propelling force to move said bolt When loose in said slots, throughout the range of its motion, axial tightening of said bolt adapted to exert a force thereon opposite to and at least equal to said propelling force whereby` sai-d slots are effective to exert only sheering action on said bolt through said application of force to said angle adjusting means.

WALTER F. HEROLD.

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