US2093531A

US2093531A - Spring covering apparatus

Info

Publication number: US2093531A
Application number: US90206A
Authority: US
Inventors: Alexander F Werner
Original assignee: Murray Corp
Current assignee: Murray Corp
Priority date: 1936-07-11
Filing date: 1936-07-11
Publication date: 1937-09-21
Anticipated expiration: 1954-09-21

Description

Sept. 2l, 1937.A A. F. WERNER i V. SPRING COVERING APPARATUS Filed July l1, 1936 2 Sheets-Sheet 1 C47 f0- I rfa ATTORNEYS.

Sept. 2l, 1937. A F WERNER 2,093,531

- SPRING COVERING -APPARATUS Filed July ll, 1936 2 Sheets-Sheet. 2

Hl Agfa/f (as ze' y g4 v INVENTOR fllezdzifr fer/2er Patented Sept. 21,1937

FFIQE SPRING COVERING APPARATUS Alexander F. Werner, Detroit, Mich., assignor to The Murray Corporation of America, a corporation of Delaware Application July 11, 1936, serial No. 90,206

4 Claims.

This invention relates primarily to apparatus for assembling compressible coil springs within f alpreformed fabric spring cover or shroud.

In the manufacture of mattress constructions, seat cushions and various other types of upholstered furniture, it is quite conventional in present day constructions to provide a framework in which are mounted a plurality of adjacently disposed,` similar coil springs and in which the individual coil springs are each completely surrounded by a fabric covering or shroud which closely ts the spring in its normally eX- panded condition. The utilization of these spring covers contributes materially to the quietness of operation of the spring and serves to provide one means which tends to limit the extent to which the springs are permitted to expand.

Heretofore many and various types of spring covers have been utilized for the purpose of individually enclosing each of the coil springs in a cushion construction. In the constructions known to the prior art, those spring covers which may be manufactured suliiciently economically for wide commercial use, in almost every` instance, employ a construction in which a pocket is formed by a suitable stitching operation. The springs are then inserted in the pockets and partially compressed and the pocket stitched to close the opening in the same and confine the spring in predetermined position. f

It is a primary object of the present invention to provide a machine which serves to automatically insert coil springs within pockets in a preformed fabric strip and to dispose these springs in the pocket in such a manner that further stitching operations are unnecessary in order to obtain a satisfactory and neat appearing closure of the aperture through which the spring was inserted.

In order to obtain a better understanding of the objects and advantages of the machine of the present invention, reference'may be had to applicants assignees prior co-pending application Serial No. 84,813, filed June 12, 1936, which relates specifically to a fabric strip which is `stitched toget er in such a manner that a plurality of parallel, adjacently disposed spring receiving pockets `are formed therein, each of said pockets having an interior conformed to enclose and house a coil spring.

It is a further object of the present invention to provide a machine which includes conventional means for compressing the coil spring to be inserted, and a mechanism adapted to engage the compressed coil spring to displace it from the point where it was compressed outwardly between a pair of guiding tongues which serve to guide the compressed spring into the spring receiving pocket of the covering strip. `The present invention contemplates the provision of a` machine in which the guiding tongues are so constructed and arranged that they inherently dispose the compressed coil spring longitudinally in the pocket in which it is received and, as will hereinafter be` more clearly appreciated, the spring receiving pocket is vso constructed that the` iiaps thereof covering the opening are automatically closed by the expansion of the compressed spring therein.

Still further, the invention contemplates the provision of .a machine which is extremely simple in operation, easily constructed and conveniently operated by relatively unskilled labor.

Many other and further objects and advantages of the present invention will become clearly apparent from the following specification when considered in connection with the accompanying drawings forming a part thereof.

In the drawings:

Figure 1 is a perspective view of a machine embodying `the improvements of the invention;

Fig. 2 is an enlarged transverse sectional view, taken substantially on the line 2 2 of Fig. 1, with portions broken away, illustrating the construction and arrangement of the spring compressing and feeding mechanism of the apparatus;

Fig. 3 is a vertical sectional View, taken substantially on the line 3 3 of Fig. 2, showing the mechanism for compressing the spring and the means for moving the compressed spring into the spring receiving pocket of a spring cover;

Fig. 4 is a sectional view substantially similar to Fig. 3, illustrating the manner in which the spring is fed into a spring receiving pocket by the apparatus of the present invention;

Fig. 5 is a transverse sectional View, taken substantially on the line 5-5 of Fig. 4, illustrating the spring feeding plunger and the mechanism for operating the same;

Fig. 6 is an enlarged perspective view of a strip of fabric preformed to provide a plurality of spring covers of the type primarily adapted for use in connection with the machine of the present invention; Y

Fig. 7 is a transverse sectional View, taken su stantially on the line 'l-'l of Fig. 6, illustrating in detail the cross-sectional construction of the spring covered strip shown in Fig. 6; and

Fig. 8 is a transverse sectional View, taken substantially on the line 8-8 of Fig. 6, illustrating in detail the interior construction and configuration of one of the spring receiving pockets of the strip after a coil spring has been mounted therein.

With more particular reference to the drawings, it will be appreciated that the specific` embodiment 'of the invention illustrated therein and described below is merely illustrative of one form of apparatus which is capable of performing the operations necessary to insert coil springs into cover strips and that the specific device illustrated is merely representative of one machine which has been found particularly adaptable for this use.

By way of illustration, the apparatus comprises a work table having a plane top I0 and supported on a plurality of legs II. The legs of the table may be strengthened by means of suitable cross braces I2 as is conventional in constructions of this general character.

The spring compressing and feeding mechanism forming the subject matter of the present invention may be mounted directly upon the upper surface of the table top I0. This mechanism includes a base member I5 which is illustrated as being formed of a suitable casting having a configuration which will be described in detail below. W'hile a casting has been illustrated, it will be readily appreciated that the base supporting member may be conveniently formed of sheet metal if desired.

The base casting I5 is provided at its corners with laterally projecting ears IG which have passing therethrough apertures adapted to receive bolts I'I, which bolts may pass through suitable holes in the table top I0 and provide means for securing the apparatus as a whole in position upon the top of the table. The casting I5 has formed in the upper portion thereof a guideway 20 of substantially trapezoidal crosssection which is adapted to receive a plunger hereinafter described in detail. A movable adjusting plate 22 may form one of the side walls of this guideway 2U and the plate 22 may be adjusted by means of a series of set screws 23 threadably received in the casting I5 and retained in predetermined adjusted position by means of lock nuts 24. The guideway 20 serves to receive the plunger 26 which is adapted for longitudinal movement therein and is of a cross-sectional conguration adapted to smoothly fit within the guideway. It will be apparent that the fitting of this plunger 26 within the guideway may be conveniently controlled by the adjusting plate 22.

The rear end of the plunger 2E is bifurcated to provide a pair of projections 28 through which passes a bolt 29 providing a pivotal connection for the upper end of a bell crank arm 3i), which bell crank arm is pivoted in a bracket 3| secured to one of the reinforcing members I2 of the table. The bolt 29 preferably passes through a square block 33 which is received between a pair of projections 34 formed on the upper end of the bell crank arm 30, thus permitting pivotal movement of the bell crank arm 30 to effect horizontal movement of the plunger 26. The lower end of the bell crank arm 3i! preferably extends forwardly and at its extreme end is flattened out to provide a pedal 31 adapted to be engaged by the foot of the operator of the machine. A tension coil spring 33 preferably interconnects an intermediate point of the lower bell crank arm to the under side of the table in order that the plunger 26 will normally be retained in substantially the position shown in Fig. 3. As will be appreciated by reference to Figs. 3, 4 and 5 of the drawings, the upper surface Ill of the table is provided with a slot 39 to permit free movement of the upper bell crank arm through the table.

Directly above the forward portion of the guideway 20 is permanently secured a cylindrical housing lll which is preferably provided with a flange 4I at its lower end, through which flange passes a pair of bolts 42, thus providing means for securing the cylindrical housing 45 in position upon the base casting I5. The internal diameter of the housing 4D is sufliciently large to receive a coil spring of a size the machine of the present invention is adapted to accommodate. Likewise the guideway 2D has a minimum width slightly greater than the maximum diameter of the springs which the machine is adapted to insert in the spring covers hereinafter described in detail.

While any suitable means may be utilized for the purpose of compressing the coil springs, the apparatus shown includes a piston like plunger 45 having a handle 46 and a transversely extending cross pin 49 which latter is adapted to be received in suitable L-shaped notches 43 formed in the upper portions of the side walls of the cylindrical housing 40. From the foregoing it will be appreciated that an expanded coil spring 4I may be conveniently dropped into the cylindrical housing and that the lower end of this spring will rest upon the lower surface of the guideway 20 immediately beneath the cylindrical housing 40. The plunger 45 may then be inserted and pushed downwardly by means of the handle 45, compressing the spring 41 until its axial length is substantially the saine as the height of the guideway 20. The lower surface of the plunger 45 will then form a smooth continuation of the upper surface of the guideway and the coil spring hio at this time is compressed approximately the maximum amount. The handle 46 may be twisted to seat the cross pin 49 in the L.-shaped notches 4S, Athus rmly locking the spring 4l' in compressed position. A pair of sheet metal tongues 50 and 5I extend forwardly from the open front end of the guideway 20 and serve to form substantial continuations of the upper and lower surfaces thereof. These tongues 50 are preferably of a maximum width substantially equal to the width of the guideway at the point of juncture therewith and taper gradually to rounded points at their extreme outer ends. It will be seen by reference to Figs. 2, 3, and 4 that the tongue 50 is slightly longer and projects slightly farther than the tongue 5I, the purpose and function of transversely by means of lines of stitching 55., The strip of material is folded to provide a body portion 56 having a width substantially equal to the length of the spring member which it is adapted to house when the spring member is in expanded condition and the edge portions 5'II and 58 are folded upon the body portion in overlapping relation prior to the stitching operation. It will be appreciated that when the strip is transversely stitched across by means of lines of stitching 55, a plurality of adjacently disposedl will be formed. It will be appreciated that access to these pockets may be had through the opening formed by the marginal edges of the portions 51 and 58 of the strip, which portions normally lie in overlapping relation. The construction of `this spring cover strip per se forms the subject matter of applicants assignees prior co-pending application referred to above and a more complete understanding of its construction may be had by reference thereto.

In the utilization of this strip with the machine `of the present invention, the marginal edge of the underneath portion 51 of the fabric strip is pulled out and slipped over the upper tongue 50 which extends from the machine and, as has been described above, projects substantially farther than the underneath tongue I. It will be seen that the underneath to-ngue 5l will engage the marginal edge of the portion 58 and retain these flaps in open position to permit the insertion of a compressed coil spring therein. The manner in which this assembly is accomplished will be clearly seen by reference to Fig. 4.

A coil spring is iirst inserted in the cylindrical housing 40 and compressed by means of the plunger 45. The spring cover is inserted upon the projecting tongues 5D and 5l in the manner described above and the foot pedal 31 is then gradually depressed, effecting a vertical movement of the plunger 26 which serves to push the compressed coil spring' 41 outwardly between the tongues 50 and 5I and into the opening of the spring receiving pocket which has been formed in the strip by means of the transversely extending lines of stitching 55. Due to the fact that the upper tongue is substantially longer than the lower tongue, it will be seen that, as the vertical convolutions of the spring reach the extreme end of the lower tongue 5I, these convolutions will, due to the natural resiliency of the spring, be moved downwardly and permit the upper end of the spring to expand outwardly into substantially the position shown in Fig. 4, thus seating the upper end of the spring 41 in one end of the spring pocket in which it is received.

It will be appreciated that as the flaps 51 and 58 are withdrawn from the tongues 5i) and 5| due to the overlapping relation of these flaps and the fact that the inner apis pulled outwardly, the opposite end of the spring will naturally be seated in the opposite end of the pocket and the flaps will automatically be restored to overlapping pcsition, thus automatically closing the opening through which the spring was inserted.

From the foregoing it will be apparent that the machine of the present invention provides extremely smooth and satisfactory means for assembling coil springs within spring covers of this generic type and that as a result of the assembly operation, the pocket in which the spring is received is automatically and neatly closed by the expansion of the coil spring therein and further stitching operations are entirely unnecessary.

As is explained in detail in applicants assignees prior co-pending application referred to above, adjacent spring pockets in the cover strip are separated by spaced double lines of stitching and consequently the strip maybe severed at any desired point in order to provide individual cover springs or a strip containing a plurality of springs each individually housed in a separate pocket of the same cover, as may be desired.

It will be appreciated that the specic embodiment of the apparatus disclosed herein is merely illustrative of the generic inventive concept presented in this application. Many other and further forms and modications thereof, falling Within the scope of the invention as defined in the subjoined claims, will be clearly apparent to those skilled in the art.

I claim as my invention:

l. Apparatus of the class described comprising a pair of fiat, spaced, substantially horizontally extending tongues adapted to enter the opening in a fabric spring cover, and means for projecting a compressed coil spring outwardly between said tongues, one of said tongues being longer than the other whereby said spring is swung into horizontal position as it elongates.

2. Apparatus of the class described comprising a pair of flat, tapering projecting tongues disposed in spaced relation and both adapted to enter the opening in a fabric spring cover, means for projecting a compressed coil spring outwardly between said tongues, one of said tongues projecting farther than the other whereby said spring upon expansion is moved into a position substantially parallel to said tongues.

3. Apparatus of the class described comprising a pair of flat spaced tongues adapted to enter the opening in a fabric spring cover, means for projecting a compressed coil spring outwardly between said tongues, one of said tongues being of substantially less width in its end portion and the other of said tongues projecting out further than said rst mentioned tongue whereby said spring as it expands will be swung into a horizontal position.

4. Apparatus of the class described comprising a pair of iiat sheet metal tongues disposed in spaced parallel relation, the ends of said tongues being tapered and adapted to enter the opening in a fabric spring cover, means for projecting a compressed coil spring outwardly between said tongues whereby the same serve to retain said spring in compressed condition as it is moved therebetween, one of said tongues being substantially longer than the other whereby expansion of said spring serves to swing the same through 90.

ALEXANDER F. WERNER.