US3744846A - Seating construction - Google Patents

Abstract

A seating construction consisting of a frame, a generally horizontal seat deck panel, a generally vertical back deck panel using from the rearward edge of the seat panel, a bell-crank lever pivoted in the frame on a horizontal transverse axis adjacent the juncture of the seat and back panels, and having upwardly and forwardly projecting arms, the forward edge of the seat panel being connected to the frame and its rearward edge being connected by resiliently extensible members to the upwardly extending arm of the lever, the lower edge of the back panel being secured to the forwardly extending arm of the lever, and its upper edge being connected to the frame by resiliently extensible members.

Description

United States Patent 1 Platt et a1.

1451 July 10, 1973 SEATING CONSTRUCTION [75] lnventors: Thomas W. Platt; Harmon W.

Arnold; Lloyd E. Tieman, all of Carthage, Mo.

[73] Assignee: Flex-O-Lators, lnc., Carthage, Mo.

[22] Filed: Sept. 16, 1971 [21] Appl. No.: 180,974

Primary Examiner-Francis K. Zugel Attorney-John A. Hamilton [57] ABSTRACT A seating construction consisting of a frame, a generally horizontal seat deck panel, a generally vertical back deck panel using from the rearward edge of the seat panel, a bell-crank lever pivoted in the frame on a horizontal transverse axis adjacent the juncture of the seat and back panels, and having upwardly and forwardly projecting arms, the forward edge of the seat panel being connected to the frame and its rearward edge being connected by resiliently extensible members to the upwardly extending arm of the lever, the lower edge of the back panel being secured to the forwardly extending arm of the lever, and its upper edge being connected to the frame by resiliently extensible members.

10 Claims, 5 Drawing Figures [52] US. Cl. 297/452, 297/307 [51] Int. Cl. A47c 7/16 [58] Field of Search 247/452, 285, 455, 247/309, 316, 320, 307, 308, 456

[56] References Cited UNITED STATES PATENTS 2,586,433 2/1952 Lepp 297/455 X 3,030,147 4/ 1962 Kinnebrew 297/452 2,832,398 4/1958 Liljengren 297/456 X 3,462,196 8/1969 Arnold 297/455 3,610,688 10/1971 Arnold 297/452 1,768,383 6/1930 Van Hove 297/309 X PAIENIE JUL 1 0 I973 By I. o 0 El man SEATING CONSTRUCTION This invention relates to new and useful improvements in seating structures, and has particular reference to seating structures including both seat and back cushions which are spring supported for softness and depth of yielding for greater comfort.

The primary object of the present invention is the provision of a seating structure of the character described in which the back cushion is attached to and moves vertically with the seat cushion, as the latter yields vertically under the weight of the occupant. In most seating structures the seat and back cushions are mounted independently in a rigid frame, with most of the occupants weight of course supported by the seat cushion, so that if the occupant jostles or bounces on the seat cushion, a certain friction and sliding occurs between his back and the back cushion. This effect, though most pronounced in automotive seating where vertical bouncing normally occurs continuously due to the roughness of road surfaces and normal driving conditions, also occurs in furniture seating, and is a contributing cause to the discomfort and fatigue resulting from long periods of driving or sitting.

Various attempts have been made to solve this difficulty by securing the lower edge of the back cushion, or the spring deck thereof, to the rearward edge of the spring deck of the seat cushion, so that the back cushion moves vertically with the yielding of the seat cushion. These attempts, while partially successful, have been subject to the difficulty that the juncture of the back and seat decks must itself be floating, that is, freely movable both horizontally and vertically without restraint, and that as a result, yielding of the seat cushion tends to pull the lower edge of the back cushion forwardly. The back cushion therefore in turn tends to force the spine of the occupant in a slouching curvature which is highly objectionable from a postural point of view, and which is itself a cause of discomfort, fatigue, and even pain when occupying the seat for long periods of time. The present structure solves the problem by interconnecting the seat and back spring decks, not directly as has heretofore been practiced, but to the respectively opposite ends of a bell crank lever pivoted in the frame on a horizontal transverse axis adjacent the juncture of the seat and back spring decks. This lever functions to translate downward yielding of the seat deck into downward movement of the back deck, as desired, but at the same time prevents any resultant forward movement of the lower edge of the back deck.

Another object is the provision of a seating structure of the character described wherein the seat and back decks, while constituting panels generally inelastic in their own planes, and deriving their yieldability transversely of their planes from elastic edge supports, as is inherently required when using the lever action described, are so formed as to possess substantial resilient resistance to flexure transversely of their planes. If they were limply pliable, they would yield by hammocking", yielding most deeply at the point of loading. Such hammocking is not conducive to good seating posture, encouraging slouching and causing eventual discomfort and fatigue. Stiffening of the deck panels translates a portion of this hammocking" yield into a platform" type of yielding, in that the panels remain more nearly planar as they yield, thereby providing better comfort. In some cases, stiffening of the seat panel also provides a desirable tilting action of the seat, as will appear.

Other objects are simplicity and economy of construction, efficiency and dependability of operation, and adaptability for use in many different types of seatmg.

With these objects in view, as well as other objects which will appear in the course of the specificatiomreference will be had to the accompanying drawing, wherein:

FIG. I is a vertical sectional view of a seating structure embodying the present invention, with the padding and upholstery layers omitted, being a sectional view taken on line I-I of FIG. 3,

FIG. 2 is a sectional view, partially broken away and foreshortened, taken on line IIlI of FIG. 1,

FIG. 3 is a sectional view taken on line III-III of FIG.

FIG. 4 is an enlarged detail view similar to a portion of FIG. 1, but showing a slight modification of structure, and

FIG. 5 is a fragmentary sectional view taken on line VV of FIG. 4.

Like reference numerals apply to similar parts throughout the several views, and the numeral 2 applies generally to a seating frame having a horizontal rectangular seat portion supported by floor-engaging legs 4 and including a front rail 6, rear rail 8, and side rails 10, and a back portion including side uprights l2 rising from each side rail 10 adjacent its rearward end, and a horizontal top rail 14 connecting the upper ends of said uprights. The structure also includes a seat deck panel indicated generally at 16, and a back deck panel indicated generally at 18. Each of said panels includes a pair of parallel side strands 20 and 22 each comprising, as best shown in FIG. 4, a spring steel core wire 24 over which is applied a sheath 26 of soft, indentable material such as twisted paper, plastic or the like. Extending between said side strands, at right angles thereto, is a continuous series of closely spaced apart, parallel cross wires 28 of spring steel, said cross wires being of substantially smaller gauge than core wires 24 of the side strands. Each end of each cross wire is secured to the associated side strand by being twisted tightly about the sheath 26 of said side strand, in indenting relation thereto, and then twisted about itself to form a knot" 30. The knotting provides a secure connection preventing the cross wires from pulling free of the side strands in usage. The sheaths 26 provide a good purchase for the cross wires on the side strands, and also prevent the rubbing or grating "wire noises which would otherwise occur. Each panel is also provided with a series of intermediate strands 32 extending parallel to side strands 20 and 22 in regularly spaced relation therebetween. Said intermediate strands are pierced by each of cross wires 28 at its point of intersection therewith, being formed of twisted paper, plastic or the like, but without core wires, for this purpose. Said intermediate strands serve to maintain a generally uniform spacing between the cross wires throughout their lengths.

Seat deck panel 16 is arranged generally horizontally over the seat portion of frame 2, with side strand 20 thereof overlying front rail 6 of the frame, and secured thereto by staples 34 if the frame is wood, or by other suitable fasteners if said frame is metal, and with side strand 22 thereof disposed forwardly of rear rail 8 of the frame. Rear deck panel 18 is arranged generally vertically over the back portion of frame 2, with its side strand 20 extending horizontally and transversely be tween uprights 12, and connected to top rail 14 by a series of transversely spaced apart, generally vertical coil springs 36. Each of said springs is hooked at its lower end around strand 20, and is hooked at its upper end in a triangular hanger 38 secured to top rail 14 by staples 40 or other suitable fasteners. The lower side strand 22 of the back panel is disposed just above and behind strand 22 of the seat panel. The lateral edges of both the seat and back panels are not connected to the frame, and are freely movable with respect thereto.

A bell crank lever 42 constituting an angle iron extends horizontally and laterally between side rails of the frame, just forwardly of rear frame rail 8. The axis of the lever is longitudinal of the angle iron, each end of said angle iron being pivoted, by means of a bracket 44 welded therein, on a stub shaft 46 affixed in the adjacent side frame rail 10 by nuts 48, and projecting inwardly therefrom. The two stub shafts are of course coaxial. The angle iron provides a lever arm 50 projecting upwardly from the pivot axis, and a lever arm 52 extending forwardly from the pivot axis.

The lower edge of back panel 18 is secured to the forward edge of lever arm 52 by a series of transversely spaced apart links 54, each of said links being provided at its upper end with a hook 56 engageable downwardly over strand 22 of the back panel, and at its lower end with a hook 58 engageable upwardly in a hole 60 formed therefor in the forward edge portion of lever arm 52. In the species of the invention shown in FIGS. l-3, the rear side strand 22 of seat panel 16 is connected to the upwardly extending leg 50 of lever 42 by a series of transversely spaced apart coil springs 62,

each of said, springs being hooked at its forward end' about seat panel strand 22, and hooked at its rearward end into a hole 64 provided therefor in the upper edge portion of lever arm 50. Springs 62 extend beneath the lower side strand 22 of the back panel, and between links 54, so that there is no interference therebetween. The use of stiff core wires 24 in the panel side strands 20 and 22 permits the use of fewer, more widely spaced connector members such as springs 36 and 62, and links 54, since they transmit the stresses imposed thereon by a number of cross wires 28 to a single connector, without undue flexure of the core wires. in the species of the invention shown in FIG. 4, the rear side strand 22 of seat panel 16 is connected to lever arm 50 by a series of transversely spaced apart links 66 (one shown) instead of springs 62, each of said links being provided respectively at its forward and rearward ends with hooks 68 and 70 engageable respectively about strand 22 of the seat panel, and in holes 64 of lever arm 50. Links 66, as well as links 54, are of course substantially rigid and inextensible.

Although not shown, it will be understood that the usual padding and upholstery layers are applied over the seat and back panels as is common and well understood in the art, it being preferable that there be no direct connection between the seat upholstery and back upholstery. The close spacing of cross wires 2&[310- vides ample support for padding material, preventing it from gradually working into and through the spaces between the cross wires. Intermediate strands 32 also assist in this respect.

Considering first the operation of the species of the invention shown in FIGS. 1-3, it will be seen that as a person applies his weight to seal panel 16 and thereby deflects it downwardly, springs 62 exert an increased forward force on lever arm 50, pivoting said lever in a counterclockwise direction as viewed in FIGS. 1 and 4, and thereby causing links 54 to pull back panel 18 downwardly as permitted by the yielding of springs 36. Thus the back panel tends to move upwardly and downwardly in unison with the deflection of the seat panel, and the friction or rubbing between the occupants back and the back cushion which would otherwise occur when the occupant varies the deflection of the seat by vertical jostling is eliminated orgreatly re duced. At the same time, while the rearward edge of seat panel 16 moves forwardly at least to some degree as said panel is deflected, due both to the extension of springs 62 and to the pivoting of the lever, the lower edge of the back panel cannot shift forwardly since it is connected directly to the lever by links 54. Thus the occupants lower back is not forced forwardly to compel a slouching curvature of the spine, and greater comfort is preserved. The stiffness of panel cross wires 28 is also important, in that they tend to reduce the simple hammocking thereof which would occur under load if they were pliably flexible. Since they impart to the panels a substantial resistance to flexure about any line parallel to the axis of lever 42, they cause the yielding of the panels to be converted partially from simple hammocking to a platform type of yielding, maintaining a somewhat more nearly planar form as they are deflected. Since neither a full hammocking nor a completely stiff, board-like panel would provide the best comfort, balancing or proportioning the two effects by proper selection of the stiffness of wires 28 is necessary to provide the highest degree of comfort, although this is at least partially a matter of personal preference.

It will be seen that as long as either the forward or rearward connections of seat panel 16 or the upper or lower connections of back panel 18, are resiliently yieldable transversely to pivot axis 46, both the seat and back panels are resiliently supported by that resiliently yieldable connection. This is a distinct advantage regardless of which of the four connections is made yieldable, since it provides resilient support for both panels from a single set of springs connected to only one panel. This is a valuable advantage in simplicity and economy, since the springs represent a major item of expense. However, it is a primary object of the invention that the back panel move vertically in unison with the seat panels, and since the back panel is moved vertically by pulling force at its lower edge, it is essential to this action that the top connection of the back panel be yieldable transversely of lever axis 46, as provided by springs 36, and as at least greatly preferred that the bottom connection of the back panel be inextensible transversely to said axis, as provided by links 54. This arrangement provides that the entire pivotal action of the lever is translated into vertical movement of the back panel. Likewise, it is preferred that the forward edge of the seat panel be directly and inelastically secured to the frame, as by stapeles 34, since this provides for the full translation of the horizontal component of the deflection of the seat panel into forward motion of the rearward edge of the seat panel, to provide better action of the lever, rather than into rearward motion of the forward edge of said seat panel, which would be inoperative to pivot the lever. In fact, so far as efficient lever action alone is concerned, it would be preferable to use the links 66 of FIG. 4 rather than the springs 62 of FIG. 1 to secure the rearward edge of the seat panel to lever 42, the panels then deriving their entire resilient support from top springs 36. The FIG. 4 structure would provide all of the advantages thus far described. Springs 62, by their extension provide that not all of the forward motion of the rearward edge of the seat panel is translated into pivotal motion of the lever, the degree of lever movement and resultant vertical motion of the back panel therefore being reduced. Also, the increased forward movement of the seat panel, as permitted by the extension of springs 62, tends to shift the occupants hips further forwardly with respect to the back panel, and thereby to deprive his lower back of the support of the back cushion. This latter effect is perhaps very slight, but is not in accordance with best practice.

Nevertheless, despite their discussed disadvantages, the use of springs 62 is preferred over the use of links 66 in veiw of at least two valuable, and partially ofisetting, advantages derived from their use. First, the series of springs 62 spaced apart transversely of the seat can yield unequally, yielding to the greatest degree directly beneath the occupants hips. This permits the seal panel, at its rearward edge, to bow transversely to conform to or wrap around the posterior of the occupant thereby providing greater comfort. This transverse conforming action cannot take place when using links 66 instead of springs 62, since said links tend to hold the rearward edge of the seat panel in a substantially straight line. Second, the extension of springs 62, in connection with the direct connection of the forward edge of the seat panel to the frame, and with the resilient stiffness of cross wires 28 of the seat panel, provides that the seat panel will tilt downwardly to the rear when loaded, somewhat in the manner of a platform pivoted at its forward edge and resiliently supported at its rearward edges. This tilting action encourages the occupant to keep his hips well to the rear where his lower back is well supported by the back cushion, and discourages forward movement of the hips into a slouched position, thereby overcoming or greatly reducing any tendency of springs 62 to shift the occupants hips forwardly by their extension. This tilting action does not occur when links 66 are used in place of springs 62, since the tilting results from extension of the springs while links 66 are not extensible.

Moreover, any disadvantages of springs 62 in reducing the lever action, or in shifting the occupants hips forwardly, by reason of their extension, can be greatly reduced, if not entirely eliminated, by the proper selection of the relative strengths of springs 62 and 36. Preferably, springs 62 are somewhat weaker than springs 36, or more springs 36 than springs 62 are used, to provide a greater total resistance to extension. lf properly selected, a condition is reached wherein the occupant, in originally settling his weight into the seat, causes extension of springs 62 to a condition in which they are virtually "fully extended" and are greatly stiffened against further extension, while springs 36 are still relatively easily extensible. Thereafter, during subsequent bouncing or jostling of the occupants weight, springs 62 function primarily as links in the same manner as links 66, being subject to very little further extension. As such, they provide virtually the same full lever action as provided by links 66, and do not cause any further forward shifting of the occupants hips relative to the back, so that the occupant remains comfortable,

assuming that he originally seated himself with his lower back properly supported by the back cushion. At the same time, springs 62 still provide their desired function of permitting the seal panel to conform transversely to the occupants posterior and providing for downward and rearward tilting of the seat panel.

While we have shown and described certain specific embodiments of our invention, it will be readily apparent that many minor changes of structure and operation could be made without departing from the spirit of the invention.

What we claim as new and desire to protect by Letters Patent is:

l. A seating structure comprising:

a. a frame,

b. a flexible, generally planar seat deck panel disposed generally horizontally in said frame,

c. means connecting the forward edge of said seat panel to said frame,

d. a flexible, generally planar back deck panel rising upwardly from the rearward edge of said seat panel,

e. means connecting the upper edge of said back panel to said frame,

f. a bell crank lever pivoted in said frame on a horizontal transverse axis adjacent the juncture of said seat and back panels and having a pair of arms extending respectively upwardly and forwardly from its pivotal axis,

g. means connecting the rearward edge of said seat panel to the upwardly extending arm of said lever, and

h. means connecting the lower edge of said back panel to the forwardly extending arm of said lever, at least one of connecting means 0, e, g, and h being resiliently yieldable in a direction transverse to the pivotal axis of said lever.

2. The structure as recited in claim 1 wherein said seat and back panels include resilient members whereby said panels have substantial resilient resistance to flexure transversely of their planes, about any line thereof generally parallel to the pivotal axis of said lever.

3. The structure as recited in claim 2 wherein said seat and back panels each comprise:

a. a pair of parallel resilient side strands, said side strands being disposed respectively at the forward and rearward edges of said seat panel and at the upper and lower edges of said back panel, and

b. a series of parallel resilient cross wires extending transversely between and secured at their ends to said side strands.

4. The structure as recited in claim 3 wherein each of said side strands includes a spring steel core wire relatively heavy as compared to said cross wires, and a sheath of soft, indentable material covering said core wire, each of said cross wires being wrapped tightly about said sheath in indenting relation thereto and then twisted about itself.

5. The structure as recited in claim 1 wherein connecting means e is resiliently yieldable in a direction transverse to the pivotal axis of said lever.

6. The structure as recited in claim 1 wherein connecting means e is resiliently yieldable in a direction transverse to the pivotal axis of said lever, and wherein connecting means h is rigidly inextensible in a direction transverse to the pivotal axis of said lever.

seat panel includes resilient members imparting to said panel a substantial yieldable resistance to flexuure thereof transversely of its plane about any line thereof generally parallel to the pivotal axis of said lever.

10. The structure as recited in claim 8 wherein connecting means g has a lesser total resistance to resilient extension than connecting means e.

Claims (10)

1. A seating structurE comprising: a. a frame, b. a flexible, generally planar seat deck panel disposed generally horizontally in said frame, c. means connecting the forward edge of said seat panel to said frame, d. a flexible, generally planar back deck panel rising upwardly from the rearward edge of said seat panel, e. means connecting the upper edge of said back panel to said frame, f. a bell crank lever pivoted in said frame on a horizontal transverse axis adjacent the juncture of said seat and back panels and having a pair of arms extending respectively upwardly and forwardly from its pivotal axis, g. means connecting the rearward edge of said seat panel to the upwardly extending arm of said lever, and h. means connecting the lower edge of said back panel to the forwardly extending arm of said lever, at least one of connecting means c, e, g, and h being resiliently yieldable in a direction transverse to the pivotal axis of said lever.

2. The structure as recited in claim 1 wherein said seat and back panels include resilient members whereby said panels have substantial resilient resistance to flexure transversely of their planes, about any line thereof generally parallel to the pivotal axis of said lever.

3. The structure as recited in claim 2 wherein said seat and back panels each comprise: a. a pair of parallel resilient side strands, said side strands being disposed respectively at the forward and rearward edges of said seat panel and at the upper and lower edges of said back panel, and b. a series of parallel resilient cross wires extending transversely between and secured at their ends to said side strands.

4. The structure as recited in claim 3 wherein each of said side strands includes a spring steel core wire relatively heavy as compared to said cross wires, and a sheath of soft, indentable material covering said core wire, each of said cross wires being wrapped tightly about said sheath in indenting relation thereto and then twisted about itself.

5. The structure as recited in claim 1 wherein connecting means e is resiliently yieldable in a direction transverse to the pivotal axis of said lever.

6. The structure as recited in claim 1 wherein connecting means e is resiliently yieldable in a direction transverse to the pivotal axis of said lever, and wherein connecting means h is rigidly inextensible in a direction transverse to the pivotal axis of said lever.

7. The structure as recited in claim 6 wherein connecting means c and g are rigidly inextensible in a direction transverse to the pivotal axis of said lever.

8. The structure as recited in claim 6 wherein connecting means c is rigidly inextensible, and connecting means g is resiliently yieldable, in directions transverse to the pivotal axis of said lever.

9. The structure as recited in claim 8 wherein said seat panel includes resilient members imparting to said panel a substantial yieldable resistance to flexuure thereof transversely of its plane about any line thereof generally parallel to the pivotal axis of said lever.

10. The structure as recited in claim 8 wherein connecting means g has a lesser total resistance to resilient extension than connecting means e.

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