US2302479A - Spring structure - Google Patents

Description

Nov. 17, 1942. s, TALLMADGE 2,302,479

SPRING STRUCTURE Filed March 17, 1941 3 Sheets-Sheet 1 'FIG.2. v

INVENTOR. E ERETT S. TALLMADGE ATTORNEYS N 1 4 E. s. TALUMADGE SPRING STRUCTURE- FiledvMarch 17, 1941 3 Sheets-Sheet 2 INVENTOR. E'VERETT- s. TALLMADGE BY r ATTORNEY;

Nov. 17, 1942. E. s. TALLMADGE SPRING STRUCTURE 3 Sheets-Sheet 3 Filed March 1'7, 1941 lOO - IOO INVENTOR.

EVERETT S. TALLMADGE m I ATT Patented Nov. 17, 1942 SPRING STRUCTURE Everett S. Tallmadge, Robbinsdale, Minn, assignor to Flexsteel Spring Corporation, Minneapolis, Minn, a corporation of Minnesota Application March 17, 1941, Serial No. 383,838

16 Claims.

' cushioning effect.

Another object is to provide a spring structure that is strong and durable, economical to manufacture, and efficient in operation.

Other objects, advantages and novel details o-f'construction of this invention will be made more apparent as this description proceeds,

especially when considered in connection with g the accompanying drawings, wherein:

Figure 1 is a perspective view of a spring structure embodying my invention;

Figure 2 is a transverse sectional view taken substantially on the line 2-2 of Figure 1;

Figure 3 is a longitudinal sectional view taken substantially on the line 3-3 of Figure 1;

Figure 4 is a top plan view of a slight modification;

Figure 5 is a transverse sectional view taken substantially on the line 5-5 of Figure 4;

Figure 6 is a longitudinal sectional view taken substantially on the line 6-6 of Figure 4;

Figure 7 is a top plan view of another modification;

Figure 8 is a perspective view of another modification.

Referring now to the drawings, A is the frame, B is the seating surface, and C are intermediate supporting springs of a spring structure embodying my invention.

As shown, the frame A is substantially squareshape in plan and is preferably formed from a single length of inwardly opening light weight channel-shaped stock. At the front corners of the frame are mitered joints l9 and II between the front crossbar l2 and the side rails l3 and it, while at substantially the center of the rear crossbar I2 the ends of the channel stock are held in abutting relation by a suitable tiebar I5 welded to said stock. The lower side it of the channel stock is wider than the upper side ll thereof and is engageable with a suitable support (not shown) for the spring structure. In the present instance the channel stock is curved at IS, I9, 2!! and 2|, respectively, to provide rounded corners.

The seating surface B is curved both longitudinally and transversely relative to the frame A and preferably comprises a series of substantially parallel transversely extendingelongated leaf springs 22, 23, 24, 25 and 26, respectively. As shown, thesprings 22 and 26 are at the front and rear of the frame and are wider than theintermediate springs 23 to 25, inclusive. Preferably the frontwide spring 22 and the adjacentintermediate spring 23 are arched across the frame and have theircrown portions 24' and 25', respectively, substantially in alignment at approximately the longitudinal median line of the frame, while the rearwide spring 26 has adepressed portion 21 in longitudinal alignment with thecrown portions 24' and 25 of thearched springs 22 and 23. The intermediate spring 2A is only slightly arched across the frame, while theintermediate spring 25 is substantially straight across the frame, hence theintermediate springs 23, 24 and 25, respectively, provide a stepped-down structure between the front andrear springs 22 and 26. To stiffen and reinforce the structure, theleaf springs 22 to 25, inclusive, have longitudinally extending embossed narrow substantially trough-shaped portions 28, 23, 3B and 3|, respectively, while therear leaf spring 26 has two substantially parallel relatively long embossed substantially trough-shaped portions 32 and 33 and is provided at opposite ends of said embossed portions with relatively short embossedportions 34 and 35, respectively. Therear leaf spring 26 is also provided at its rear edge with adownturned flange 36.

The intermediate supporting springs C are also leaf springs and are preferably inverted substantially L-shape in configuration. Preferably theupright legs 31 of the L-shaped springs are rigidly secured at their lower ends to the side rails I3 and I4 of the frame at spaced points thereof, while theother legs 38 of the Us extent inwardly beneath and are secured to theleaf springs 22 to 26, inclusive, at opposite ends thereof. In the present instance, theleaf springs 22 and 23 are supported by and secured to the forward L shaped springs C; theleaf spring 24 and 25 are supported by and secured to the intermediate L- shaped springs C; and therear leaf spring 23 is supported upon and secured to the rear L-shaped springs C. Preferably narrowauxiliary leaf springs 39 extend along the inner edges of the forward L-shaped springs C beneath the end portions of theleaf springs 22 and the structure.

By referring to Figure 1, it will be noted that thefront leaf spring 22 projects forwardly beyond the front L-shaped springs C and is cut away at and 4|, while therear leaf spring 26 projects rearwardly beyond the rear L -shaped springs C and is cutaway as at 42 and 53, respectively, to afford clearance between theend portions 44 and 45, respectively, of said leaf springs and the adjacent L-shaped springs C so that the latter will have proper freedom of movement during the flexing action of the spring structure. Thus, better flexing action is obtained as a result of this construction.

Actually theforward edge 55 of thefront leaf spring 22 is in advance of the front crossbar l2, and as the latter is well below and in rear of said edge, there is no interference with the action of the spring other than to act as a safety stop under an extreme load.

The rear flangededge 36 of therear leaf spring 26 is curved-like and is just in advance of the rear crossbar l2 of the frame. Thus, the rear 23 to strengthenleaf spring 26 is sufficiently forward of the rear crossbar |2 and at a suitable height relative thereto to flex without metal-to-metal contact. To provide the proper contour for upholstery material or padding (not shown) that may be mounted on the spring structure, the opposite ends of theleaf springs 22 and 25 are rounded as at 41 and 48, respectively.

In Figures 4 to 6, inclusive, I have illustrated a slight modification wherein the frame A is substantially square-shape in plan and is preferably formed of two channel members and 5|, respectively. Themember 5|] is U-shape in plan and forms thefront crossbar 52 andside rails 53 and 54 of the frame, while themember 5| forms the rear crossbar of the frame and is bowed outwardly from one side rail to the other.

55 and 55, respectively, are attaching flanges or extensions projecting forwardly from opposite ends of the bowedportion 5! of the rear crossbar and overlapping and rigidly secured to theside rails 53 and 54 at their rear ends. Preferably thechannel members 50 and 5| are formed of relatively light gauge metal and open inwardly. Thelower sides 5! and 58, respectively,

of thechannels 53 and 5| are relatively wide and z are engageable with a suitable support (not shown) for the spring structure, while theupper sides 59 and 60 of said members are narrow but adequately stiffen and reinforce said members.

In the present instance, the lower sides 5'! and 58 of the channel members are cut away as at BI, 62, E3 and 64, respectively, and the bases and 65, respectively, of the channel members are curved at 61, 68, 69 and 10, respectively, to provide rounded corners. It will also be noted that therear crossbar 5| is deeper than thefront crossbar 52 andside rails 53 and 54. Thus, a comparatively light but sturdy and durable frame is provided.

The seating surface B is curved both longitudinally and transversely relative to the frame A and preferably comprises a series of substantially parallel transversely extending elongated leaf springs H, 12 and 13, respectively. As shown, the springs 1| and 13 are at the front and rear of the frame and are quite wide, while thesprings 12 are intermediate the spring H and i3 and are relatively narrow. In each instance, the springs are arched upwardly over the frame A and have their crown portions l4, l5

and 16, respectively, substantially in alignment at approximately the longitudinal median line of the frame. Likewise, in each instance thecrown portions 14, 15 and 16 of the springs have upwardly embossed downwardly opening troughshaped portions 11, T8 and 19, respectively, that extend longitudinally of the arched portions of the springs across the longitudinal median line of the frame and serve to stiffen and reinforce the springs.

The intermediate supporting springs C are also leaf springs and are preferably inverted substantially L-shaped in configuration. Preferably the upright legs of the springs are rigidly secured at their lower ends to the rails '53 and 54 at spaced points thereof, while the other legs 8| of the Ls extend inwardly beneath and con stitute supports for opposite ends of the leaf springs ll, 12 and 13, respectively. As shown, the inwardly extending legs 8| oft he Ls incline upwardly from theupright legs 80 and are preferably riveted at their inner ends of the leaf springs ll, '12 and 13, respectively. Preferably the spring TI andadjacent spring 12 are secured to the springs C at the front end of the frame; two of thesprings 12 are secured to the center springs C; and thespring 13 and adjacent spring '12 are secured to the springs C at the rear end of the frame.

In order that theseating surface 13 will be curved longitudinally of the frame with the lowest part of the curve about midway the ends of the frame, the springs C at opposite ends of the frame incline toward the center of the frame and are spaced above the lower edges of the side rails 53 and 54, while the springs C at the center of the frame are secured at a lower elevation so that the lower edges thereof are substantially flush with the lower edges of therails 53 and 54. Thus, the springs 'H and I3 and adjacent springs l2 incline toward the center of the frame, while the two center springs 12 are at a lower elevation and have opposite ends thereof in a common horizontal plane substantially parallel to therails 53 and 54.

For reinforcing thenarrow leaf springs 12, I have provided supporting or secondary spring leaves D between the inturned legs 8| of the springs C and the ends of thesprings 12. As shown, these secondary spring leaves D are similar to those shown in my application Serial No. 338,623 filed June 3, IMO, and serve the same purpose. Such spring leaves D are held in place by therivets 82 that secure thesprings 12 to the springs C.

Preferably the wide springs H and 73 at the front and rear of the structure overhang the L-shaped spring C to which they are secured so as to properly support upholstery material o padding therefor (not shown) of a seat construction. Actually the straight forward edge of the leaf spring 7| at the front end of the str1lcture is in advance of thefront crossbar 52. and as the latter is well below and in rear of saidedge 95, there is no interference with the action of the spring other than to act a safety stop under an extreme load.

The rear edge 9| of the spring l3 at the rear f the structure is curved like therear crossbar 2 but terminates short thereof. Thus, the is sufficiently forward of the crossbar at a suitable height relative thereto to without rnetal-to-rnetal contact.

.referably the leaf spring TI is cut on the bias at opposite ends thereof as at 92 and 93, re-

the forward end of the structure are rounded at 94 and 95, respectively.

In Figure '7 I have illustrated another modiflcation wherein twoauxiliary crossbars such as I are used in the frame construction. Preferably such bars are located in vertical alignment with openings llll between the springs H, 12 and 13 so there will be no metal-to-metal con tact between such springs and the auxiliary crossbars when the structure is subjected to a normal load. However, under an extreme load the upholstery material or padding therefor on the springs ll, 12 and 13 would rest upon the auxiliary crossbars I00 which, in such instance. would serve as a safety or limiting stop.

In Figure 8 I have illustrated another modification wherein a wire H9 of relatively heavy gauge is employed at the forward edge of the spring structure for engagement with the upholstery material or padding therefor (not shown) when it is placed upon the spring structure. The wire has a portion Ill extending transversely across the structure in advance of the forward L-shaped springs C to which they are secured so versely extending connecting leaf springs I I2 and H3, and is provided at opposite sides of the structur with open return-bends ll4 and I65 that extend rearwardly to and are disposed upon the leaf spring H3. For holding the wire Hi). there is a metal strip H6 at the longitudinal median line of the structure terminally secured to the leaf spring H3 and to the portion Ill of the wire. Preferably this strip H6 extends beneath the leaf spring I I3 and over the leaf spring H2 and is provided intermediate its ends with a longitudinally extending substantially troughshaped embossed portion H! to stiffen and reinforce the same.

Many other adaptations of my invention may be made. For example, the inverted L-shape leaf springs of the type illustrated herein could be used at the rear of a seat, for example, at the rear of an automobile seat, wherein springs of other configuration, for example, C-shape of the type illustrated in my application Serial No. 338,623, aforesaid, may be employed at the front thereof for supporting intermediate or connecting longitudinally extending leaf springs instead of transversely extending springs such as 22 to 26, inclusive. In fact, the L-shaped springs may be used on either or both sides or at either or both front and rear portions of any supporting seat frame structure, for the purposes herein set forth. Also, this idea could be embodied in a bed spring structure if desired.

Thus, from the foregoing, it will be apparent that each spring structure has a saddle effect. Under a load the transversely extending leaf springs will flex at opposite ends of the embossed portions thereof, while the L-shaped springs will flex inwardly and downwardly relative to the side rails of the supporting frame. The embossed portions of the leaf springs serve to stiffen and reinforce the structure so that it will properly support and cushion the load. Such embossed portions do not necessarily prevent all flexing of the springs at said embossed portions.

In some instances, the embossed portions are shallow enough so that there is appreciable flexing at such points. The embossed portions do, however, control this flexing movement. As a result, the maximum comfort is afforded by the spring structure.

What I claim as my invention is:

1. A spring structure having a frame, and a seating surface yieldably supported upon said frame and curved longitudinally relative to said frame, said'seating surface consisting of a series of spaced transversely extending leaf springs, some of said leaf springs being arched, adjacent springs at opposite ends of the frame being inclined toward the center of the structure.

2. A spring structure having a frame, and a seating surface yieldably supported upon said frame and curved transversely relative to said frame, said seating surface consisting of a series of spaced transversely extending leaf springs, some of said leaf springs being arched, the leaf springs at opposite ends of the structure being wider than the intermediate springs, one of said wide springs having a marginal downturned stiffening flange.

3. A spring structure having a frame, and a seating surface yieldably supported upon said frame and curved both longitudinally and transversely relative to said frame, said seating surfac consisting of a series of spaced transversely extending leaf springs, some of said leaf springs being arched, the leaf springs at opposite ends of the structure being wider than the intermediate springs, the wid spring at the forward end of the structure overhanging the front portion of the frame.

4. A spring'structure having a frame, and a seating surface yieldably supported upon said frame and curved both longitudinally and transversely relative to said frame, said seating surface consisting of a series of spaced transversely extending leaf springs, some of said leaf springs being arched, the leaf springs at opposite ends of the structure being wider than the intermediate springs, one of said wide springs being cut on a bias at opposite ends thereof.

5.A spring structure having a frame, and a curved seating surface yieldably supported upon said frame, said seating surface consisting of a series of spaced transversely extending leaf springs, some of said leaf springs being arched, th leaf springs at opposite ends of the structure being wider than the intermediate springs, one of said wide springs having rounded ends.

6. An all-metal seat spring structure having a seating surface curved both transversely and longitudinally to provide a saddle effect, a rigid base frame, and intermediate supporting springs,

- the seating surface consisting of a series of substantially parallel transversely extending elongated leaf springs, the transversely extending springs at the front and rear of thestructure being wider than the transversely extending springs therebetween, the transversely extending spring at the front of the structure and the transversely extending spring next adjacent thereto being arched and having their crown portions substantially in alignment at approximately the longitudinal median line of the frame, the transversely extending spring at the rear of the structure having a depressed portion substantially in alignment with the crown portions just mentioned, the intermediate supporting springs being inverted substantially L-shaped leaf springs and constituting the sole supporting means for the transversely extending springs forming said seating surface, the upright legs of the Us being secured to opposite sides of the base frame and the horizontal legs of the Ls being secured in surface-to-surface relation to the transversely extending leaf springs at opposite ends thereof.

'7. An all-metal seat spring structure having a seating surface, a rigid base frame, and intermediate supporting springs, the seating surface consisting of a series of substantially parallel transversely extending elongated leaf springs, the transversely extending spring at the front of the structure and the transversely extending spring next adjacent thereto being arched and having their crown portions substantially in alignment at approximately the longitudinal median line of the frame, the transversely extending spring at the rear of the structure having a depressed portion substantially in alignment with the crown portions just mentioned, the intermediate supporting springs being inverted substantially L- shaped leaf springs and constituting the sole supporting means for the transversely extending springs forming said seating surface, the upright legs of the Us being secured to opposite sides of the base frame and the horizontal legs of the Us being secured in surface-to-surface relation to the transversely extending leaf springs at opposite ends thereof.

8. An all-metal seat spring structure having a seating surface, a rigid base frame, and intermediate supporting springs, the seating surface consisting of a series of substantially parallel transversely extending elongated leaf springs, the intermediate supporting springs being inverted L-shaped leaf sprin s and constituting the sole supporting means for the transversely extending springs forming said seating surface, the upright legs of the Us being secured to opposite sides of the base frame and the horizontal legs of the Ls being secured in surface-to-surface relation to the transversely extending leaf springs at opposite ends thereof, the transversely extending leaf springs at the front and rear of the structure 1 projecting outwardly beyond and overhanging the outer edges of their supporting L-shaped springs and being cut away over the horizontal portions of the L-shaped springs to afford clearance between portions of said transversely extending springs and said L-shaped springs so that the latter will have freedom of movement during the flexing action of the spring structure.

9. An all-metal seat spring structure having a seating surface, a rigid base frame, and inter- 1 mediate supporting springs, the seating surface consisting of a series of substantially parallel transversely extending elongated leaf springs, the intermediate supporting springs being inverted L-shaped leaf springs and constituting the sole supporting means for the transversely extending springs forming said seating surface, the upright legs of the Us being secured to opposite sides of the base frame and the horizontal legs of the Us being secured in surface-to-surface relation to the transversely extending leaf springs at opposite ends thereof, the transversely extending leaf spring at the front of the structure projecting outwardly beyond and overhanging the forward edges of its supporting L-shaped springs and being cut on the bias at opposite ends thereof so that upholstery material placed upon the structure will not be cut by said transversely extending leaf spring and the L-shaped springs will have greater freedom of movement during the flexing movement of the spring structure.

10. An all-metal spring structure having a frame, a transversely arched yieldable seating surface above the frame, and inverted L-shaped leaf springs carried by the frame and constituting the sole support for said seating surface, the yieldable surface at opposite ends of the structure being separate leaf springs inclined toward the center thereof so that opposite ends of the seating surface are higher than the center porticn thereof.

11. A seat spring structure having a seating surface curved both transversely and longitudinally to provide a saddle effect, a rigid base frame, and intermediate supporting springs, the seating surface consisting of a series of substantially parallel transversely extending elongated leaf springs, the transversely extending spring at the front of the structure and the transversely extending spring next adjacent thereto being arched and having their crown portions substantially in alignment at approximately the longitudinal median line of the frame, the transversely extending spring at the rear of the structure having a depressed portion substantially in alignment with the crown portions just mentioned, the intermediate supporting springs being inverted substantially L-shaped leaf springs and constituting the sole supporting means for the transversely extending springs forming said seating surface, the upright legs of the Us being secured to the base frame at opposite sides thereof, and the horizontal legs of the Ls being secured to the transversely extending leaf springs at opposite ends thereof.

12. An all-metal seat spring structure having a seating surface, a rigid base frame, and intermediate supporting springs, the seating surface consisting of a series of substantially parallel ransversely extending elongated leaf springs, the transversely extending spring at the front of the structure and the transversely extending spring next adjacent thereto being arched and having their crown portions substantially in alignment at approximately the longitudinal median line of the frame, the intermediate supporting springs being inverted substantially L-shaped leaf springs and constituting the sole supporting means for the transversely extending springs forming said seating surface, the upright legs of the Us being secured to opposite sides of the base frame and the horizontal legs of the Us being secured in surface-to-surface relation to the transversely extending leaf springs at opposite ends thereof.

13. A seat spring structure having a seating surface, a rigid base frame, and intermediate supporting springs, the seating surface consisting of a series of spaced transversely extending elongated leaf springs, some of said transversely extending springs being arched, the intermediate supporting springs being inverted substantially L-shaped leaf springs, the upright portions of the Us being secured to the base frame at opposite sides thereof, the horizontal portions of the Us extending inwardly over the frame and being secured to the transversely extending springs at opposite ends thereof, the transversely extending leaf springs at opposite ends of the structure being wider than the other transversely extending springs, at least one of said wider leaf springs projecting outwardly beyond and freely overhanging the outer edges of the horizontal porsupporting said transversely extending spring tions of its supporting springs.

the frame, the transversely 14. A seat spring structure having asrigid base frame, inverted substantially L-shaped leaf springs having the upright portions thereof secured to the base frame at opposite sides thereof, the horizontal portions of the L-shaped springs extending inwardly over said base frame, and transversely extending leaf springs spanning the space between and terminally secured to the horizontal portions of said L-shaped springs, the transversely extending spring at the front of the structure and the transversely extending spring next adjacent thereto being arched and having their crown portions substantially in alignment at approximately the longitudinal median line of extending spring at the rear of the structure having a depressed portion substantially in alignment'with the crown portions just mentioned.

15. A seat spring structure having a rigid base frame, inverted substantially L-shaped leaf springs having theupright portions thereof socured to the base frame at opposite sides thereof, the horizontal portions of the L-shaped springs extending inwardly over said base frame, and transversely extending leaf springs spanning the space between and terminally secured to the horizontal portions of said L-shaped springs, the transversely extending leaf spring at the front ing spring at the front of of the structure being arched and having its crown portion at approximately the longitudinal median line of the frame, the forward portion of said transversely extending spring at the front of the structure projecting forwardly beyond and overhanging the horizontal portions of the foreextending inwardly over said base frame, and

transversely extending leaf springs spanning the space between and terminally secured to the horizontal portions of said L-shaped springs, the transversely extending leaf spring at the'front of the structure being wider than adjacent transversely extending springs and projecting forwardly beyond and overhanging the horizontal portions of the foremost L-shaped springs, the overhanging portion of the transversely extendthe structure being free to flex relative to said foremost L-shaped springs.

EVERETT S. TALLMADGE.

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