US2250486A - Wire spring and spring structure - Google Patents

Description

Patented July 29, 1941 WIRE SPRING AND SPRING STRUCTURE Jacob Kronheim, Cleveland Heights, hio,,as-

signor to John 0. Lincoln, Scottsdale, Ariz.-

Application May 24, 1938, Serial No. 209,713

2 Claims.

This invention relates to fiat springs of sinuous or similar shape, used for seats of upholstered furniture, cushionedautomobile seats or the like, and more parti arly to the type of springs described in Patent 0. 2,047,411 dated July 14th 1936. Springs of this type embody an upper axially compressible and extensible seating portion, a yielding, rearwardly and downwardly extending supporting means at the front end of the seating portion, and a downwardly extending,

Fig. 1 shows a vertical sectional view through a spring structure mounted in the open frame of a cushioned seat, the spring structure em-' bodying springs provided with an elevated front yielding supporting means at the rear end of the seating portion. The supporting means of the springs are either integrally formedv with the seating portion or rigidly connected to the opposite ends thereof to effect upward bulgingand longitudinal stretching of the seating portion when a load is placed thereon.

These springs are assembled to spring structures by individually mounting the springs with their supporting means upon opposite rails of an open frame so that all seating portions of the springs are situated in a plane above the frame, and by interconnecting all seating portions of the springs to a continuous seating surface, generally to be covered with padding and upholstering material and a customary roll front edge so.

asto insure proper mounting and holding of loose seat cushions.

As well known, construction of a rolledge and its attachment to a seating surfaceis a slow and costly process which necessitates employment of highly skilled labor.

The principal object of the present invention is to reduce manufacturing and labor costs in building of upholstered furniture by providing springs of improved construction and designer!!- bodying at their frontseating portions elevated means substantially equal in action to that of a front r011 edge.

Another objectof the invention is the provision of an improvedwire spring having an elevated seating portion and integral elevated means at the front of the "seating portion equal in action to that of a front roll edge. I

In addition, the invention has certain other marked superiorities which radically distinguish ;it from presently known structures. The-improvements or superior characteristics embodying certain novel features of construction are- -clearly set-forth in the following specification and the appended claims; and a preferred form of embodiment of the invention is hereinafter shown with reference to the accompanying draw ing formfiig 'p'art of the specification.

In the drawing: 7

edge to permit of proper support of seat cushions on the padded spring structure without use of a special front roll edge; the section being taken on line |-I of Fig. 2.

Fig.2 is a cross sectional view through the spring structure and chair base shown in Fig. 1, the section being taken on line 22 of Fig. 1.

Fig. 3 is a fragmentary vertical sectional view through the rear portion of the chair base and spring structure shown in Fig. l, the section being taken on line 3-3 of Fig. 2..

Fig. 4 is a perspective view of one of the springs used in the construction of the spring structure shown in Fig. 1; and

, Fig. 5 is a perspective view of one of the spring hooks yieldingly tying the rear end of the spring structure to the rear rail of the open frame;

Referring now more particularly to the drawing, reference numeral 2 represents the frame of a chair embodying at its bottom portion a rectangular open frame 3, the front, rear and side rails 4, 5 and 6 of which are secured to thefront and rear legs 1 and 8 of the frame 2. Open frame 2 has mounted on its front and rear rails 4 and 5 a plurality of flat springsS, made of sinuous-shaped or horizontally corrugated steel wire. These springs each include rearwardly and downwardly inclined front and rear'supporting means or'lever arms ill, II respectively, adapted to support the proper seating portion l2 of the spring in an elevated position, which supporting means extend from'the opposite ends of the said seating portion. The front supporting means or supporting arm 10 is looped'at its free end to form two oppositely wound coils I 4 and I5, arranged in a plane substantiallyre'ctangular to the plane of the seating surface '12, which coils k are of diflerent elasticity, coil l4 having less windings than coil l5 and therefore being stifler than said latter coil. Preferably, as shown, front lever arm I0 is bent and offset as at It to prohibit contact of the-coils l4 and I5 with the seating portion I! when a 'load is placed upon said portion. The free end of coil I5 is extended forwardly of said coil and secured to the front rail 4 by means of an angular offset l6, metal bracket I! being used for such purpose.

The. rear supporting means H for the seating portion lZ-is formed as a, curved extension of said surface, curved at its rear portion to semi-circular shape. This rear supporting means'has thereto, which hook 20 is held in proper position on rail 5 by staples 2|.

The above described construction of the rear supporting means ll of the spring 9 materially simplifies manufacturing of said spring and is of great importance for spring seat structures in which the seating portions of all springs are interconnected to a substantially unitary seating surface 22 by means of an edge wire 23 and wire braces 24, which wires are secured to the springs by clips 25, all as shown in the drawing. In such spring seat structure the movement of the seating surface is mainly controlled by the rear supporting means which in the described construction has rather low resistance against forward movement of the seating surface when under load. This deficiency in the structure is overcome by the arrangement of torsion spring means 26 which pivotally engage a rearward extension 21 of the edge wire 23. and are secured to the rear rail 5 by means of staples 28. The torsion spring means 28 are made of spring steel wire and embody a coiled portion 29, having extended from its opposite ends a hook-shaped lever arm 30 and an angular resting and attachment arm 3 I which latter is secured to the rail 5 in a manner previously described.

The coil l5 of the front supporting means and the coil IQ of the rear supporting means effect a substantial reduction of the forward movement'of the structure under load. Thus coil I4 has less resiliency than coil l5, and coil l8, having less resiliency than coil l9, permit of the coils l5 and I!) being contracted to effect a substantially vertical downward movement of the seating surface when a load is placed thereon until the elasticity vided with a roll edge to give proper support to the legs of a person sitting on such structure and to propely support the customary seat cushions in such a fashion that the cushions do not slip from their support. The present spring structure embodies means .which permit of discarding the edge roll to facilitate manufacturing at decreased cost. For that purpose the front part of the seating portions l2 of all springs 9 are forwardly and upwardly inclined as 32 to permit of formation of an elevated front edge on the finished seat without necessitating the slow and costly attachment of special means for building a roll edge at the front of the spring structure.

Having thus described my invention, what I claim is:

1. A spring for cushioned seats or the like comprising a horizontally corrugated seating portion including at its front end a ledge upwardly and outwardly inclined with respect to the axis of said seating portion, a front supporting means'rearwardly and downwardly extended from the front end of said ledge in inclined relation with respect thereto, and rear supporting means integrally extended from the. rear end of said seating portion.

2. A spring for cushioned seats or the like comprising a horizontally corrugated seating portion including at its front end a corrugated ledge upwardly and outwardly inclined with respect to the axis of said seating portion, and inclined front and rear supporting means integrally extended from said seating portion at an inclination with respect thereto.

JACOB KRONHEIM.

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