US 3709559 A
Chairs and other seating units are made with seats and, where present, backs, each comprising a plurality of sinuous spring wires secured to rigid frame members of the seating units, these rigid frame members being themselves held apart by one or more other rigid frame members. The sinuous spring wires are in their natural state shaped in circular or cylindrical arcs which are partially but not completely flattened in the completed seats and backs, to place the springs in tension and to aid in their retention by the frame. The spring wires touch or come quite close to each other at least once per cycle, and a thin sleevelike plastic coating surrounds the wires and follows their sinuous shape. It also surrounds the rigid frame members to which they are secured and links the wires and frame together and links the wires to each other wherever they touch, to provide a unitary seat or back assembly. The springs are, however, secured firmly to the frame, and the plastic is not relied on for rigid attachment. In preferred forms of the invention, the plastic coating has a Shore A durometer between 45 and 90, so that the assembly is held together by the plastic coating without substantially restraining the flexing of the spring wires, and the coating itself provides a spring action between adjacent wires by stretching and contracting, thereby giving a two-way stretch action.
Description (OCR text may contain errors)
United States Patent 1 Rowland  FURNITURE FOR SEATING PEOPLE  Inventor: David L. Rowland, 49 West 55th Street, New York, NY. 10019 22 Filed: March22, 1971 211 Appl.No.: 126,576
 US. Cl. ..297/445, 267/111, 297/56,
297/457  Int. Cl ..A47c 4/00, A47c 7/00  Field of Search ..160/403, 404; 5/353, 354;
 References Cited UNlTED STATES PATENTS Primary ExaminerCasmir A. Nunberg Att0rneyOwen, Wickersham & Erickson [451 Jan. 9, 1973  ABSTRACT Chairs and other seating units are made with seats and, where present, backs, each comprising a plurality of sinuous spring wires secured to rigid frame members of the seating units, these rigid frame members being themselves held apart by one or more other rigid frame members. The sinuous spring wires are in their natural state shaped in circular or cylindrical arcs which are partially but not completely flattened in the completed seats and backs, to place the springs in tension and to aid in their retention by the frame. The spring wires touch or come quite close to each other at least once per cycle, and a thin sleevelike plastic coating surrounds the wires and follows their sinuous shape. It also surrounds the rigid frame members to which they are secured and links the wires and frame together and links the wires to each other wherever they touch, to provide a unitary seat or back assembly. The springs are, however, secured firmly to the frame, and the plastic is not relied on for rigid attachment. In preferred forms of the invention, the plastic coating has a Shore A durometer between 45 and 90, so that the assembly is held together by the plastic coating without substantially restraining the flexing of the spring wires, and the coating itself provides a spring action between adjacent wires by stretching and contracting, thereby giving a two-way stretch action.
41 Claims, 37 Drawing Figures PATENTEUJAM ems 3,709,559
' SHEET 1 OF 7 L FI6.37 INVENTOR F1619 DAWD L. ROWLAND BY a; an
L ATTORNEY PATENTEDJAN' 9 I973 SHEET 2 UF 7 INVENTOR. DAVID L. ROWLAND PAIENTEUJAI' a ma SHEET 3 UF 7 INVENTOR. DAVID L. ROWLAND ATTORNEY mimmm 9197a 3.709.559
( o n/W W gm v ATTOQNEY INVENTOR. DAVID L. ROWLAND v mzmim ems 3.709.559
SHEEI 7 [1F 7 INVENT I DAVID L. ROW v OQWAUQMfi W ATTORNEY FURNITURE FOR SEATING PEOPLE BACKGROUND OF THE INVENTION This invention relates to seating units, such as chairs, sofas, stools, benches, automobile and other transportation seating, and the like. Each of these seating units is characterized by the seat and back being made up of a series of sinuous spring wires partially held together by a thin sleevelike plastic coating around each of the wires that bridges the wires where they touch. In addition, however, the wires are secured firmly to rigid frame members of the seating units at or near their ends by any of various rigid securing means.
A hard seat can, at best, only approximate a comfortable shape, since human posteriors vary greatly. While seats theoretically might be tailor-made for each individual, this would be costly and would require carrying the tailor-made seats to wherever they would be used. A better solution to the problem is to provide a seat which automatically tends to shape itself to each user's posterior. The provision of a seat with proper resilience in the right places is thus an object of this invention.
The seated human body rests mainly on the ischial tuberosities, the two lower points of the pelvis. Additionally it rests on the meaty and fatty flesh in a l to 2 inch radius therefrom. A flat, hard surface becomes uncomfortable quickly because the load is concentrated on the small area of the ischial tuberosities, and the flesh immediately covering them is compressed with great force. Spreading this load over a larger area makes a more comfortable condition as the unit area compressive force is substantially reduced. Automatically shaping the seat surface to generally conform to the sitter helps to accomplish this. On the other hand, spreading this area over too wide a surface, such as is the case when a seat is too soft, results in engulfing the sitter too deeply and also often results in a lack of security, which comes from feeling insufficiently supported. One often sees automobiles in which the owner has gone to the trouble of installing wooden slat accessory pads to make the seat firmer.
Dr. Bengt Akerblom, eminent Swedish authority on human posture, says in his book Standing And Sitting Pasture, published by A. B. Nordiska Bokhandeln, 1948 Naturally a rather soft seat would distribute the pressure over the tuberosities better than a hollowed rigid one. They are, however, so small that there would be very little sense in having a very soft and resilient seat. On the contrary, such a seat might be expected to transfer a not inconsiderable proportion of theweight on to tissues which are not adapted for bearing it. The best consistency for the seat would therefore be such that although it gave under pressure, it only gave slightly." 2
Proper resilience alone is not enough, either. Independent freedom of movement, such as that found in a two-way stretchable material, more appropriately conforms to the human posterior shape, which itself has compound curvature.
While certain spring and padding combinations can afford proper yieldability and firmness, practically all padding materials have the fault of being good heat insulators. In a cold room, this might be acceptable temporarily, but people usually wear clothes appropriate for temperature conditions anyway and to sit for any length of time on a heat-insulative material becomes uncomfortable, because of inhibition of dispersion of body heat in the human posterior area. To get to a cooler spot, the person squirms. Anyone who, while wearing a swim suit, has tried to sit down on the seat of a convertible car that has been out in the hot sun, knows that such heat conditions of the seat can be unbearable.
Some prior art seats have been made from spacedapart wires, but in them the spacing has been such that too much load has been concentrated on too few wires, and this textural discomfort has made the use of upholstery pads requisite for such seats.
An ideal seat therefore has:
1. Proper shape (including proper compound curvature).
2. Proper resilience and firmness (resilience provides shape adaptability to each sitter).
3. Proper heat dispersion.
4. Proper surface contact area.
An object of this invention is to provide a seat more nearly approaching the ideal than has been achieved in the past.
Each seating unit of this invention comprises a series of sinuous spring wires, partially held together by a thin sleeve-like plastic coating around each of the wires, bridging the wires where they touch. The spring wires are firmly secured to the chair frame.
The invention may be considered as an improvement over my earlier U.S. Pat. No. 2,803,293. In that patent, each of the sinuous springs had a hook on each end which partially encircled a rigid frame member. This hooking did not positively prevent relative movement of the wires to the frame, nor did it hold them in proper position relative to each other prior to the seats being coated with plastic. Partly because there was only line contact, at best, between the wire and the frame (and unless the chair frame size was exactly matched with the size of the hook, there would be contact at only two points), the'hook tended to rotate when subjected to force, as when someone sat on the chair. Even after the chair had been coated with plastic, this instability was such that when the chair was being sat upon, the wire hooks tended to walk along the chair frame as the sitter shifted his position, thereby distorting the seat area, with the result of making the seat uncomfortable.
Also, the chair of US. Pat. No. 2,803,293 was expensive to manufacture because the springs had to be carefully positioned and the positioning retained while the chair was dipped. Further, great care had to be taken that the springs themselves were not distorted by the spring manufacturer while they were being made; otherwise, the spring junctures could not be properly bridged across by the plastic.
These difficulties are overcome in the present invention, in which rigid securement of the ends of the springs to the chair frame is provided, and reliance is not made on the plastic for that particular purpose, although it does coat that portion and no doubt provides some extra forces holding the springs to the frame. However, it is important here that the actual holding is done by the rigid securement of the springs to the frame.
Another disadvantage of my prior chair was that the chair seat and the back were substantially planar, and even if they did have a slight bowing, they were installed in a generally flat at-rest shape of the springs so that there was little spring tension or cushioning action. In the present invention it becomes possible to obtain much more tension, cushioning, and resilient support from the springs by virtue of making the springs as circular or cylindrical segments that are somewhat flattened when they are put on to the chair frame but are not forced completely flat, rather than making the chairs from a series of substantially flat springs. The resulting tension of the wires pulling inwardly is utilized in retaining the wires to the frame.
Another important feature of the invention is the provision of a two-way stretch, which is obtained by using plastic coatings that lie within a prescribed range of Shore A durometer. The springs can continue their flexing in the usual manner without being overly limited by the coating, and also the spring assembly can flex the plastic where it bridges the wires. In the prior patent it was possible to use a wide variety of materials, including hard plastics such as nylon which would certainly hold the wires together but would not themselves stretch, so that all the stretch had to be accomplished by the wires when such materials were used. This would give the seat some yieldability, but usually only in a cylindrical surface, rather than in the compound curve which results in a seat that has two-way stretch. Nor was this two-way stretch recognized or found in this type of chair until a desired range of durometers was discovered in the present invention and used in'proper relationship to suitable gauges of wires to enable achievement of this goal.
Even two-way stretchability and proper wire gauge alone have been found to be insufficient. Resistance to bounciness is an important property when considering the resilience necessary for a comfortable seat, and it is especially necessary in transportation seating, where up-and-down motion tends to result in harmonic vibration, for harmonic vibrations subject the sitter to vertical oscillations for some time after a bump has been traversed. Bounce dampening is thus requisite, and is partly accomplished in the present invention by proper choice of durometer of the plastic coating. if the durometer is too low a value, the springs are too free and are too ready to bounce. if the durometer is too high, the seat is too stiff and lacks the proper two-way stretch quality desired. Proper choice of durometer according to the principles of this invention, enables the plastic to serve as a shock absorber and provides a snubblng action against bounce. Variation of gauge, of length and of temper of adjacent wires is a further means of dampening bounce vibrations in this invention.
The amount of the seating area occupied by the wire gauge, and the thickness of the plastic coating are also important features to be considered, and little, if any, thought about these features is evident from the prior art. For example, in the drawings for US. Pat. No. 2,803,293, it can be shown that the metal occupies only about 14 percent of the silhouette of the area, whereas I have now found that for proper results the spring steel should occupy a minimum of 17 percent of the silhouette of the area and a maximum of about 75 percent, with the range of 17 percent to 25 percent,
preferable generally. The coating should generally be about one-half as thick as the wire, in order to givebridging, proper heat insulation, and proper stretchability, but values in the range of from one-fifth of the wire thickness to about equal to the wire thickness can be used. Also, the size of the void areas between the coated wires should be no greater than about percent of the seat area used to accommodate one adult sitter and should not be less than about 2 percent, with about 60 to 75 percent being preferable.
SUMMARY OF THE INVENTION The present invention comprises a seating unit in which the seats and backs are made from a series of arcuate sinuous spring wires, each of which is rigidly attached at its opposite ends to a rigid frame member of the seating unit. Each wire extends between these frame members in a circular arc, and the circular arcs are parallel to each other. The wires touch or closely approach their adjacent wires at least once per cycle.
A thin sleevelike plastic coating surrounds both the spring wires and the rigid frame members to which they are secured, following the sinuous shape of the spring wires and bridging between them and joining them at points where they touch or closely approach each other, and also joining and bridging between the rigid frame members and the wires. This thin plastic coating preferably leaves most of the area of the seat open in between the wires but links the wires together and the wires and the frame members together into a unitary assembly, with the seat or back shaped as a rather flat cylindrical arc, thereby placing the spring wires in tension. When used as a seat, the rise from one end to another after flattening is preferably between a quarter of an inch and an inch. For the back, the curvature may be somewhat greater, such as a radius of 7 to l 1 inches. The plastic preferably is in the range of Shore A durometer between 45 and and seems to be best at about 75, so that the two-way stretch action previously referred to is obtained.
Note that in this invention the wires cannot go straight' across. They must undulate in order to be stretchable. Moreover, they must be connected to each other by stretchable means. This contrasts with my earlier patent which may allow flexible joints but does not require stretchable joints. A lSO-pound person sitting normally on a chair of the present invention will depress it by at least 1 inch (or at least one-eighteenth part of seat height) and, at most by about 3 inches (about one-sixth part of seat height). As stated, the juncture is stretchable and flexible, but it is so tough that it cannot be pulled apart under usual human sitting conditions. Putty and kneaded erasershave a rubbery quality, but not the elasticity, stretchability, flexibilit or resilience requisite here.
To get the best results in the present invention, the area of the silhouette of the wires prior to coating should be at least 17 percent but not more than about 75 percent of the seat area, especially of a typical area. For sufficient bridging, heat insulation, and surface cushioning, the coating should be at least 20 percent of the wire diameter.
If the seat were made from spring metal alone, the comfort would be insufficient, particularly when used in moving vehicles. It would be too bouncy. Proper durometer and proper thickness of the coating relative to the wire thickness help to prevent this bounciness. The reason is similar to the reason why a car is not comfortable with metal springs alone; it also needs the rubber, air, and hydraulic fluid in the combination of rubber-pneumatic tires and hydraulic shock absorbers, before it can be comfortable. Wire gauge, length, and temper variations also produce bounce-dampening in the invention.
BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:
FIG. 1 is a view in perspective of a chair embodying the principles of the invention.
FIG. 2 is an exploded view in perspective of the chair of FIG. 1, showing the various elements, parts of the seat and back being shown as though they were an assembly, which actually they are not until they are put on the chair and then dipped in plastic. Some of the springs have been separated out, and one is shown in its original, pre-installation circular-arc shape. The radii before and after installation are shown and compared.
FIG. 3 is a fragmentary view in perspective on an enlarged scale of a portion of the chair of FIGS. 1 and 2, showing the rigid attachment of the spring wires to a rigid frame member, the plastic coating being partly broken away to show the underlying metal members.
FIG. 4 is a still further enlarged detailed view of the attachment of one spring member to the rigid frame member.
FIG. 5 is a view in section taken through the line 5- 5 in FIG. 4.
FIG. 6 is an enlarged fragmentary view in perspective of a portion of a modified form of chair, in which the springs are rigidly attached to the rigid frame members in a different manner and in which a front rim member" is also attached to the frame and secured by plastic to an adjacent spring of the seat. The plastic is partly broken away and in part is shown in section. One of the wires is broken off to show a part of the frame that and also including a border wire.
FIG. 9 is a view similar to FIG. 6 of another modified form of the invention, again with some parts broken off or broken away and some parts shown in section. Some of the spring wires are of different shape from others.
FIG. 10 is a view in section taken along the line l0 10 in FIG. 6.
FIG. 11 is a view like FIG. 10 but with a peripheral wire added.
FIG. 12 is another view similar to FIGS. 6 and 9 of an additional modified form of the invention, with the plastic broken away and shown partly in section.
FIG. 13 is a similar view of still another modified form of the invention, with parts being broken off or broken away to show some of the parts which would otherwise be hidden.
FIG. 14 is a view similar to FIG. 13 of still another modified form of the invention with some parts again being broken away and shown in section and some parts being broken off to disclose other parts.
FIG. 15 is a diagrammatic view showing the difference in curvature between an individual spring as originally made in a rather closed circular arc and the flattened circular are that results when the spring is installed on the frame of the seating unit.
FIG. 16 is a view in perspective of a modified form of chair embodying the principles of the invention. Some portions of the fabric covering are broken away to show the structure beneath them.
FIG. 17 is a view in side elevation of another modified form of chair embodying the principles of the invention.
FIG. 18 is an enlarged view in section of the attachment of the seat and back to a rigid frame member in FIG. 17 and also in FIG. 16.
FIG. 19 is a view in side elevation of still another form of chair embodying the principles of the invention.
FIG. 20 is a view in perspective of a chair embodying another modified form of the invention.
FIG. 21 is a view in side elevation of the chair of FIG. 20.
FIG. 22 is a view in side elevation showing how a compound curve is obtained in the chair of FIGS. 20 and 21.
FIG. 23 is an enlarged top plan diagrammatic view in two halves illustrating the two-way stretch effect of the wires and plastic assembly.
FIG. 24 is a view in side elevation of an opened folding chair embodying the principles of the invention.
FIG. 25 is a view in side elevation of the folding chair of FIG. 24 in folded position.
FIG. 26 is a diagrammatic view of the relative arcs and radii of back and seat for the chair of FIG.- 24.
FIGS. 27 to 35 are all top plan fragmentary views of various patterns of the arcuate sinuous members, in each instance with portions of the wire shown uncovered and with plastic linking the spring members together. Various patterns are shown as illustrative of the many, many more that are possible in this invention.
FIG. 36 is a view in front elevation of the lower portion of a modified form of chair embodying the principles of the invention.
FIG. 37 is a view in side elevation embodying the principles of the invention in another modified form.
DESCRIPTION OF SOME PREFERRED EMBODIMENTS An Example of a Chair Embodying the Invention, FIGS. 1-5
Many, many types of seating members may embody the principles of the invention, including chairs, sofas, davenports, benches, stools, automobile seats, bus seats, camp chairs, and so on.
A chair 50 is shown in FIG. 1 for the purpose of giving one example of a seating unit that can embody the principles of the invention. This example is not to be construed as representing all types of seating units or even all types of chairs embodying this invention, for such chairs can vary greatly in frame structures, appearance and so on, some of the variations being shown in other drawings. The basic part of this invention is concerned with the seat and back of the chair and with their attachment to the frame of the chair.
The chair 50 has front legs 51 and 52 and rear legs 53 and 54, which continue up, preferably at an angle, to form back frame portions or members 55 and 56. In this particular chair there are cross frame members 57, 58 and 59. The member 57 joins together the front legs 51 and 52, the member 58 joins the rear legs 53 and 54 together, and the member 59 joins the back frame members 55 and 56 together. Horizontal side frame portions or members 60 and 61 join the front legs 51 and 52 to the juncture of the rear legs 53 and 54 and the back frame members 55 and 56. The particular bracing and structure concerned is not critical, being only an example of what can be done. In this particular form of the invention the back frame members 55 and 56 are parallel to each other, and the side frame members 60 and 61 are parallel to each other, but this parallelism need not always be present though it is often preferred.
The side frame members 60 and 61 support a seat 62, and the back frame members 55 and 56 support a back unit 63. The seat 62 and back 63 are very similar to each other and theoretically might in some instances be identical, but usually the back unit 63 is somewhat smaller than the seat unit 62 and, in any event, is preferably made from smaller, less stiff wires. The structure of the seat 62 and the back 63 may, however, be considered substantially identical for purposes of discussion, except where differences are pointed out. Both of them are made from individual spring wires firmly secured to the chair frame, and in both of them there is a coating of plastic applied to them and to the frame members that secure them. As shown in FIG. 2, the seat 62 is secured to the side frame members 60 and 61 with the aid of securement members 64 and 65, while similar securement members 66 and 67 secure the back 63 to the back frame members 55 and 56. In this instance there is also a rim 68 for the seat 62 and a rim 69 for the back 63.
The main elements of the seat 62 are a series of springwires 70, 70a, 70b, 70c, 7012, which extend across from one side frame member to another, and the same is true in the back 63, where the wires 71, 71a, 71b, 71c, 71n are substantially identical in form to the wires 70, though preferably of smaller gauge. The wires 70, 70a, etc., may be identical to each other, and so may the wires 71, 71a, etc., though that is not always necessary or desirable, as will be seen. These wires 70, 71 are sinuous springs that are made to arch naturaliy into a circular arc, as shown at the bottom of FIG. 2 where the radius R1 of the initial state is indicated. This is also shown diagrammatically in FIG. 15. When the wires 70, etc., are installed on the seat 62, they are spread out and flattened to the position shown above and to the left of the single arched wire in FIG. 2, but the flattening does not really take place except under installation. Then its radius is R2. Furthermore. although most of the seat 62 and all of the back 63 are shown in FIG. 2 as joined together in assemblies, these assemblies are not really present, but the wires 70, 71 etc. are individual wires until after they have been stretched and installed on the seat and the whole has been coated. Typical wires of this type are of spring steel, having 0.60 to 0.75 percent carbon and 0.90 to 1.20 percent manganese. Tensile strength typically runs about 215,000 to 265,000 p.s.i., and their I Rockwell hardness is about 39-41 RC range. The
diameter of the wires preferably lies in the range of 0.05 to 0.15 inch. Too thick a wire tends to concentrate the stiffness too much and the seat is too firm, while too thin a wire makes the seat too soft.
Various means are used to anchor each end of each spring 70 or 71 to the frame members, and many of these will be desbribed as examples of the many, many more that could be given. Also, it should be pointed out that the springs 70 and 71 may have any of many different shapes, some of which are shown in FIGS. 27 through 35. They may be of the type often called nonsagging springs and sometimes sold under the trademark No-Sag. Each end of each spring 70 or 71 is firmly anchored to and secured to a frame member of the seating unit. Whether this securement relies on a friction grip or on welding or something else is optional, but in the particular chair 50 of FIGS. 1 and 2, a friction-grip type of anchorage is shown.
Each spring member or wire 70 in the seat 62 and each spring member or wire 71 in the back 63 is placed tangent to adjacent wires. Each wire 70 or 71 touches its adjacent wires at least once per cycle. The touching may be actual contact or tangency or it may be an approximate touching or a close approach, because, as will be seen, the seat 62 and back 63 are eventually held together in a way that does not require actual physical contact of the metal at each tangent point, but there is always a very close relationship if not an actual touching.
A thin sleevelike plastic coating 72 (see FIG. 3) surrounds the spring wires 70, 70a, etc., or 71, 71a, etc., follows their sinuous shape, bridges the wires where they substantially touch together, and also surrounds the frame members to which they are attached, if not indeed the entire frame of the chair. The coating 72 may be applied by dipping the entire chair S0, or it may be done by dipping only the seat 62 and back 63 and adjacent portions. The result is the chair 50 shown in FIG. 1. Preferably, the plastic coating 72 is about onehalf of the thickness of the wire 70, or in the range of one-fifth of wire thickness to about equal to the wire thickness. At the junctures, the thickness may be mostly greater, though the wires themselves may touch each other.
Securing the Frame End to the Chair Frame, FIGS. 2-5
Each spring end is, in the form of the invention shown in FIGS. 2-5, anchored to the chair side frame members 60 and 61 or back frame members 55 and 56 with the aid of the securement members 64, 65, 66 and 67. These latter are tubular segments and have a main body 73 with a series of short arcuate projecting tonv gues 74 along one edge alternating with a series of longer, out-turned tongues 75. Each short tongue 74 is used as a stop member, and each long out-turned tongue 75 is flared away from the cylindrical arc and is used as a friction-grip holding member for a wire 70. Thus, when a wire end portion 76 is slipped in, it is held between the long tongue 75 and the chair frame member 60 (or 61) with its actual end 77 abutting against the edge of the short tongue member 74, which snugly lies against the frame member 60 (or 61). In this example, the frame members 60, 61, etc. of the chair 50 are cylindrical and tubular, although this serves only as an example and will not always be the case. Each wire end portion 76 is placed into the proper position by itself; the stop member tongues 74 act as spacing members, and, since the springs 70 are all standardized, they locate the springs 70 so that they will properly touch each other as shown in FIG. 3. The wires 70 as shown have to be stretched to span the distance between the frame members 60, 61.
The rim member 68 is supported by the members 60 and 75, as shown in FIG. 5, and provides a border around the seat 62, as the rim member 68 provides a border around the back 63. (See FIGS. 1 and 2.) This rim member 68 may be anchored by positive means, or its anchoring may be by the plastic coating 72, which is put on after the rim 68 has been installed. In this instance it serves to cover the projecting curves of the foremost or rearmost wires 70, which tend to provide hooks that can catch the clothing of the sitter, and, this rim 68 with the aid of the coating 72, protects the clothes from being snagged. The securement members 64, 65 may be secured to the frame members 60, 61 by spot welding, seam welding, or other types of welding or by rivets or screws, as desired. In installation, the rims 68 and 69 are set in place by whatever means after the springs 70, 71, for seat 62 and back 63, respectively, have been installed.
Another Type of Securement, FIGS. 6 and 7 A different type of securement member 80 is shown in FIGS. 6 and 7. It comprises a tubular segment 81 secured to the frame member 61. From the tubular segment 8] are formed a series of projecting portions 82 and 83 spaced from the frame member 61, and there are a series of punched-out openings 84. Here the edges of the segment 81 provide stops for the ends 77 of the wires 70, and the projections 82 provide a mechanical holding means for each wire 70. The end 77 abuts against the continuation of the tubular segment 81, while the holding portion 82 covers part only of the punched out portion 84, preferably being made from it, while the uncovered portion of the opening 84 gives better access for installing the wires 70, etc. There is no side rim member in this instance but there is a front and (preferably a rear) rim member 85, and they may be similarly anchored into holes 86 in the portions 83. During installation the wires 70, 71 are placed in tension, and this tension helps to hold them in place during dipping. After installation of all the springs 70 and of the rim member 85, as shown in FIG. 6, the entire assembly is dipped, some of the plastic 72 being shown and other portions being removed to show the parts below it more clearly.
Another Type of Securement, FIG. 8
The securement shown in FIG. 8 resembles that of FIG. 7, but the securement member 80 has been rotated about l20, and a rim-member 68 (like that of FIGS. 1 and 2) has been snapped in place between the seat and members 60 and 61. The assembly is then dipped in plastic, as are the other constructions.
Another Type of Securing With Direct Securing to the Frame, FIGS. 9 and 10 FIGS. 9 and 10 show a form of the invention in which there is no separate securement means but in which a chair frame member 90 itself is punched to provide openings 91 through which ends 92 of the wires and rim wire 93 are projected, preferably by bending each of the wires 70 or 93 at a place spaced away from its end. The holes 91 are positively located, and they position the springs 70, 70a, etc. relative to each other to provide the necessary contact. There may be some very slight freedom of movement in this instance before the plastic coating 72 is put on, but once it is on, the parts are held very firmly, and all parts are secured together into the unitary assembly. The plastic bridging zone 94 and the tension required to put the wire 70 into the hole 91 serve to prevent the disengagement of the wire 70 from the hole 91 by an external lifting force.
FIG. 9 also shows an important modification, in,
which a wire 70b (and other similar wires) is introduced between some of the predominant wires 70, 70a etc. This wire 70b of FIG. 9 has a different shape from the wires 70 and 70a and has a different curve length. This means that the wire 70b has a different period of vibration and the resultant combination of different wires results in bounce dampening. Wires that differ in curve length or in diameter or in stiffness or spring tension all help to dampen bounce. By this means, the bounce characteristics may be greatly changed, and bounce may be fully dampened.
A Modified Securing Means, FIG. 11
FIG. 11 shows a modified securing means similar to that of FIG. 10, but with the rim member 68 added and attached to the frame by welding.
Another Form of Attachment Means, FIG. 12
In FIG. 12 the attachment of the springs 70 to the frame member 61 is made with the aid of a wire 95 formed substantially in the shape of a square wave and mostly secured to the frame member 61, as by welding, but provided at certain portions with raised portions 96 providing, in effect, loops through which the spring wires 70 enter and which substantially snugly hold them. The opposite end 97 of the square wave wire 95 acts as a stop. In this instance, a rim member 98 has an end portion 99 that abuts the end 77 of the adjacent spring wire 70 and they act as a stop for each other, although other structures are conceivable. Again, the coating 72 is provided to tie all this together and to reinforce the mechanical holding provided by the wire 95.
Another feature shown in FIG. 12 is the fact that some wires may be of different gauge than others. Thus the wires 70b, 70c, 70d are of a larger gauge than the wires 70, 700. This is to impart variation in stiffness, so that one part of the seat is stiffer than another.
Another Form of Securing Device, FIG. 13
FIG. 13 shows a frame'member 61 around a portion of which is secured a wire 100, which may be welded to it at intervals or may instead be snapped onto the frame member 61, since it is a little larger than half the circumference of the frame member 61. The wire 100 is provided with a spacing portion 101, and at intervals a channel-like portion 102 made by simply forming the wire with two segments 103 and 104 close together. These channel-like portions 102 are in this instance used to anchor hooked ends 105 of the wires 70. This is somewhat like that looping shown in US. Pat. No. 2,803,293 but differs in that here the wire hooks 105 of the spring wires 70 are positively maintained by the precisely located and secured channel portions 102 of the securement wire 100. The rim 106 may be secured in a similar manner at the front and rear edges, and no rim member is needed along the side edges. The rim may be secured differently if desired. The entire assembly is then coated with the coating 72 in the same manner.
Yet Another Form of Attachment, FIG. 14
FIG. 14 shows another means of attachment in which the wires 70 have hooked ends 1 l resembling those of my earlier patent but in which a frame member 111 is provided with recesses or grooves 112 to receive these hooks 1 l0 and positively position them. The spring wires 70 themselves are held firmly in position both before and during the dipping with the plastic 72. This drawing has also been used to illustrate a modified form of rim wire 113 at the forward edge, with the wire itself sinuous, somewhat like a true sine curve, filling in much of the space left by the main spring wires 70, so that there is no strong projection tending to catch clothing etc. Once the wires are held in place, dipping is assured with good results, and the coating 72 is then provided.
The Significance of Flattening the Cylindrical Arc, FIGS. 2 and FIG. 15 shows diagrammatically what happens when the wires 70 of FIG. 2 are installed on the chair 50 of FIG. 1. The round circular arc with radius R1 is flattened from the shape shown at the left of FIG. 15 to the shape shown at the right-hand side of FIG. 15, where it has a larger radius R2. This is also shown somewhat in FIG. 2. The wire 70 then has a broader span, and its arc is somewhat flattened so that it can be used as a seat. It has a crown height h shown in FIG. 15 and is still a circular are but much flatter than before.
This flattening of the arc is an important feature of the invention. By making the wires initially as circular arcs which are parallel to each other, and with the arc quite round and fairly closed and then flattening the are considerably, a large amount of desirable tension is placed into the completed seat, so that it has a springy feel to it, acting substantially as though there was a large cushion instead of simply an assembly of thin springs. The exact amount of crown height h or of curvature depends, of course, somewhat on taste but generally there' will be about a three-quarter inch crown height I: in a l6-inch wide seat. The proportion is usually best considered as being a crown height h of one-sixty-fourth to one-sixteenth of the span, or onequarter inch to 1 inch in a 16-inch wide seat.
The amount of force required to flatten a seat of typical dining chair size is important as well. For purposes of the present invention, it has been found that a collection of springs in a seat 70 requiring a force of between 340 pounds and 680 pounds to flatten it, give the seat a proper tension, and preferably the amount is around 500 pounds. This is the force exerted in pulling the ends 76 and 77 of all the wires apart to an appropriate distance to fit onto the chair frame portions 60 and 61 For the chair back, somewhat different rules apply and it will be noticed that in the chair of FIG. 1, as in most such chairs, the arc of the back extends rearwardly and is not something that the sitter tends to flatten, but rather he tends to increase the arc curvature, reducing its radius.
In both the seat and the back, the tension of the wires pulling inwardly, resulting from flattening, is the main force retaining the wires.
Significance of the Plastic Coating 72, FIG. 23
The plastic coating 72 may be chosen from various types of plastic, such as polyvinyl chloride, polyvinyl acetate, mixtures thereof, other vinyl compounds, polyethylene, butadiene, acrylic eiastomers, and so on. The material may be transparent, where that is desired, or it may be opaque and impart its own color to the unit. It may contain dye or pigment, which imparts the desired color, completely preventing view of the wires themselves and giving the appearance of constituting the actual seating material. The plastic coating 72 may be semitransparent and may give shade or tone to the overall color.
The sinuous wires 70, a, etc., are preferably not welded to each other at their points of tangency but are held together only by the plastic coating 72 with the wires either touching each other or even slightly apart from each other but closely approaching each other. The same is true of the connection between the wires 70, 71 and the rim members 68, 69, 85, 93, 98, 106, l 13 where those are present.
An important feature of the plastic coating 72 is that by choosing a proper range of durometer, a two-way stretch effect can be obtained, as illustrated in FIG. 23. The springs not only stretch in the well-known manner of non-sagging springs, but also the plastic coating 72 between the adjacent springs 70, 700, etc., may be stretched, and this two-way stretch effect gives a wide range of resilience to the seat. If the plastic 72 is too hard, there can be substantially no such stretch, and if the plastic 72 is too soft, there will be too much stretch, the springs 70 themselves are not properly availed of, the sitter will sink'too deeply into the seat and the seat or back may even be torn apart after some use. By holding the Shore A durometer of the plastic coating within critical values, the effect is right, with sufficient rigidity so that the springs are taken advantage of and so that they are held apart with sufficient resilience so that the whole is not simply encased in a rigid covering. I have found that the durometer range necessary to achieve this critical action is from 45 to Shore A durometer, with a preferable value of about 75.
In FIG. 23 there are two portions. The left portion illustrates part of a seat 62 before it is sat upon, with the springs 70 therefore in their normal configuration. A typical area 280 is shown outlined, this area comprising one complete cycle of wires 70, so that it is representative of the total area of the seat 62 so far as the percentage of metal silhouette per total area is concerned. This area can therefore be used for determining accurately the silhouette of the wire and its average occupation of the seat area. Taking the gauge or wire diameter as G, the length of the wire can be determined in terms of G by measuring the length of the center lines of all the wires 70 in the area 280 in terms of G, and the value is found to be 34G. The area 280 itself measures 14.6G by l0.7G, which is l56.22G The silhouette area of the wire in the area 280 is 346 which is 21.76 percent of the area 280. This value lies within the preferred range of I? percent to about 75 percent of the seat area mentioned earlier.
Also, the empty spaces between the coated wires should be no greater than about 75 percent and no less than about 2 percent of the area of the seat surface, and the range of about 60 percent to 75 percent is preferred. The minimum of about 2 percent is to provide sufficient air ventilation.
The wires 70 in the seat 62 lie closely adjacent each other and nearly touch at points of near-tangency, where the distance between them may be D as shown in FIG. 23 and the distance across the assembly there is T,. The plastic coating 72 forms a bridge fastening the wires 70 together at 281 and has a thickness t.
The right portion of FIG. 23 illustrates what happens when the seat 62 is sat upon. The length L, in the left portion extends to the longer length L, in the right portion. The width W in the left portion extends also to become the width W, in the right portion. The distance D in the left portion has stretched to become the distance D, in the right portion, and the distance T has become T Thus is seen the importance of the bridge or juncture 281 and of the stretchability'of the plastic 72 at this bridge or juncture 281. This, of course, is related also to the thickness t of the plastic coating 72.
A glance at the seat 62 might lead one to conclude that the surface configuration would be texturally uncomfortable. However, this conclusion would be mistaken, for the seat 62 acts differently than one might at first conclude, for the following reasons:
1. The average occupation by the wire of the typical area (i.e., 17 percent to about 75 percent) is so great that the human posterior is supported without concentrating the load too much. In contrast, if the wire occupies less than about 17 percent of the area (e.g., the 14.4 percent occupation of the FIG. 2 area in U.S. Pat. No. 2,803,293), the seat would be texturally uncomfortable.
2. The empty spaces constitute at least 2 percent of the seat area, in order to give sufficient air ventilation, and preferably occupy much more of the seat area, up to about 75 percent.
3. The wires 70 are not exposed bare metal, which would be highly heat conductive and therefore unpleasant and uncomfortable. Each wire 70 is adequately coated with plastic 72 which is low in heat conductivity; so it is pleasant and comfortable to sit upon.
4. The coating 72 lies within the range of Shore A durometers (45-90) where it is neither too hard nor too soft; in fact it tends in itself to provide some cushioning effect, and its action at the bridges 281 adds to the comfort. Without this, the seat 62 could be too hard or too soft.
5. The two-way stretch discussed above provides automatic contouring, offering minimal resistance to the human posterior. Without this two-way stretch, the seat 62 would become increasingly uncomfortable.
A Modified Form of Chair, FIG. 16
FIG. 16 shows a chair 120 incorporating a seat 121 and a back 122. The back 122 is substantially like the back of the chair of FIG. 1 with three exceptions: (l) the curve of the back 122 is vertical and forward instead of horizontal and backward, (2) the frame members 123 and 124 to which it is secured run horizontally instead of vertically, and (3) the back 122 is covered with a fabric pad 125; this last is optional. The structure of the back 122 is otherwise basically the same, and although the frame as shown is quite different in appearance, the basic point is still rigid frame members 123 and 124 to which the springs 71, 71a, etc., of the back member 122 are secured. A rigid member 126 spaces the members 123 and 124 apart rigidly. A portion of the fabric 125 is shown broken away to show the underlying structure. This is illustrative of the fact that fabric coverings can be used in any of the chairs of this invention, although often it is better not to do it because the open structure parts have advantages.
The seat 121 is basically like the back 122 but has an important difference, in that it has a sharp bend 127 spaced in front of and above the front frame member 128. This bend 127 functions to give the chair a resiliency at the front, which is extremely desirable, and also an accentuated curve at the front end making the chair more comfortable than if that curve were absent. The rear ends of the springs 70 are secured to theframe member 124.
Another Fore-and-Aft Chair Seat Arrangement, FIGS. 17 and 18 FIG. 17 illustrates another form of chair 130 differing from the chair of FIG. 16 in that the bend 127 is absent from the seat 131, and the seat 131 goes directly from the front frame member 128 to the rear frame member 124. Also, as in FIG. 16 the bottom of the back 122 and the rear end of the seat 131 are secured to the same frame member 124. This can be done in various ways, but as shown in FIG. 18, it may be done by inserting end portions 132 and 133 of both wires 70 and 71 through either the same or adjacent perforations 134 in the chair frame member 124 and using both parts 132 and 133 as anchors, and then securing the whole by the coating 72 later on. This chair 130 may be coated with a fabric coating or left with bare, plastic-coated springs.
'Another Fore-and-Aft Seat Arrangement, FIG. 19
springiness and comfort and is considered desirable by some manufacturers.
A Chair With Compound Curves, FIGS. 20-22 A chair is shown in FIGS. 20-22 which has front legs 151 and 152, rear legs 153 and 154, rear frame members 155 and 156, cross-frame members 157 and 158, side rails 160 and 161, a seat 162 and a back 163. The difference in this chair 150 is that the frame is so constructed to provide both the seat 162 and the back 163 with compound curves. Thus, the front legs 151 and 152 merge into the side frame members 160 and 161 through relatively wide-radius curved portions 164 and 165, and the rear frame members 155 and 156 have upper portions 166 and 167 that are curved. The result is that the installed seat 162, which originally (see FIG. 22) had a simple flat cylindrical curve, now has a compound curve (FIGS. and 21), for the front portion 168 of the seat is curved in the direction of the chair frame at the same time that it is arched across between the frame members 160 and 161. The back 163 is also curved at the portion 169 to follow the curved back while being arched across it. These compound curves give added comfort to seating. Straight portions at the front edge of a chair are likely to cut into the legs and to be uncomfortable and a curved portion eases that part, provided that there are no sharp cutoffs, so far as the sitter is concerned.
FIG. 22 illustrates how the chair 150 may be made. The chair 150 is first made with the frame in the shape shown in FIG. 22 and with the seat 162 and the back 163 both making simple cylindrical arcs. Then a pair of die members 170, 171 is used to apply the compound curve to the back and another pair of die members 172, 173 is used to provide the compound curve at the front and also to move the front legs 151, 152 down to where they can be touching the floor while the rear legs 153, 154 are substantially vertical. This means that the chair 150 may be first assembled and coated with plastic 72, and then the compound curve applied by bending the frame members.
A Folding Chair Embodying the Principles of the Invention (FIGS. 24 to 26) A folding chair 200 is shown in FIGS. 24 and 25, having a seat 201 and a back 202, both embodying the principles of the invention. The folding chair 200 has a pair of side frame members 203 that support the seat 201, a pair of rear leg members 204 extending to the front of the chair 200, and a pair of front leg and back frame members 205 that support the back 202.
FIGS. 24 and 25 show a significant feature of the invention. The seat 201 is crowned upwardly, and the back 202 is crowned rearwardly, so that when the chair 200 is folded, the seat 201 can nest within the back 202 as shown in FIG. 25. This enables very compact folding of the chair 200, so that the thickness of the chair 200 in a stack of such folding chairs need be no greater than the frame thickness.
This feature of compact stackability is also applicable in a non-folding but compactly stackable chair wherein seats nest compactly over seats, and backs nest compactly into backs, as illustrated by my US. Pat. No. Re. 26,071. I
Some of the features of the folding chair part are illustrated also in the diagrammatic view of FIG. 26. This shows that the seat 201 may be curved less than the back 202, and in most examples this provides a more comfortable chair 200 than if they were curved only to fit each other. The back concavity should be equal to or greater than that of the seat; in other words the radius of curvature of the seat 201 is greater than the radius of curvature of the back 202. The back 202 may vary from having a radius identical to that of the seat 201, to a radius no less than half of the radius of the seat 201, in order to secure both comfort and adequate folding. Of course when the curvatures are different,
the stacking may be somewhat less compact, but this is a disadvantage to be weighed against the other disadvantage of having the seat and back be uncomfortable when sat upon. In FIG. 26 is illustrated another unique feature of the invention. The seat member 201 has a Y crown height of between one-quarter inch and l inch.
Some of the Many Patterns of Wire Possible in This Invention, FIGS. 27 to 35 A substantially infinite number of wire patterns are possible under this invention. The one shown heretofore with the wire 70 is a very good pattern but it is not the only good one that can be used. Patterns can be used for their structural features, because of manufacturing convenience, or because of design features. Some of these features will appear from the selected forms shown, and in all of them it will be seen that the wires, whether in parallel pattern or alternate patterns,
touch each other at least once per cycle; the touching may be flush to each other in the same plane, or may be by an overlap or planes with the unit still having substantially the same plane.
FIG. 27 shows a wire 211 with vinyl covering 212 and an adjacent wire 213 with vinyl covering 212 also on it. The wires 211 and 213 are bent in the same pattern but are set to alternate, so that one is rotated 180 relative to the other; instead of each wire 211 being strictly parallel to its adjacent wire 213, their sinuosities are reversed, and the alternating effect is obtained. Alternation can give some interesting designs, such as the one shown here. The length of the one cycle has been marked on the drawing, and it will be seen that the cycle is rather long, partly due to the alternation and partly due to the wire pattern itself. Thus, the wire 211, starting from the left-hand end, has a long vertical portion 214, then a horizontal portion 215 succeeded by a short vertical portion 216, then a horizontal portion 217 preferably the same length as the portion 215. The portion 217 is followed by a portion 218 identical in length to the portion 216 and then leading to another portion 219 which is parallel to and in line with the portion 215 and of the same length again. The portion 219 is followed by a portion 220 that is longer than the portions 216 and 218 and equal in length-to the portion 214 and therefore raising the wire up toa new level. This is succeeded by a horizontal portion 221 of the same length as the portion 215 and parallel to it but displaced from it. This in turn is succeeded by a short portion 222 the same length as the portion 218 but starting from a different place, so that the succeeding portion 223 is not in line with the portions 215 and 219. Another portion 224 equal in length to the portion 222 is followed by a portion 225 in line with and equal to the portion 221, and this is followed in turn by a portion 214a identical to the portion 214 and beginning a new cycle.
The wire 213 adjacent to the wire 211 has the same pattern but is reversed, so that the wires 211 and 213 touch at the portions 215 and 219. The wires 211 and 213 touch or come close to the other wires to which they are adjacent at the portions 221 and 225. These touching portions in this instance extend for the whole width, and the plastic coating 212 covers these portions as well as the individual wires.
FIG. 28 shows a wire 230 having a sinuous shape and an adjacent wire 231 both of them being covered by a plastic 232. The length of one cycle is in this instance much shorter. The wire 230 has a flaring portion that describes what are nearly two circles 233 and 234, with the radii displaced, and these near-circles 233 and 234 are joined by a smooth connecting curve 235. Again the pattern is interesting, and the structural effects substantially the same as what have already been described. All these patterns enable the two-way stretch discussed earlier.
FIG. 29 shows a wire 240 which is made in a sinuous pattern not unlike the wire 70. The adjacent wires are overlapped so that the wire 240 lies over a wire 241 and beneath a wire 242, and the plastic covering 243 joins all the wires. This pattern provides a small opening 244 through the overlaps and a large opening 245. This makes an interesting pattern, is another way of forming the assembly, and shows that the wires do not have to actually abut or lie in the identical plane.
FIG. 30 shows a wire 250 with an adjacent wire 251 with plastic covering 252. Another type of square-wave pattern is shown giving a different pattern, and again the length of the cycle is shown.
FIG. 31 shows another form of pattern. In this case, a wire 255 actually overlaps itself with a succession of circles, so that no one wire actually lies in a single plane, but there is, of course, substantially a planar configuration. The successive wires abut each other.
FIG. 32 shows another square wave configuration with steps down and up, with wires 260, 261, etc., and plastic coating 262.
FIGS. 33 and 34 show an angular configuration and two different uses of the same wire 265 and coating 266. In FIG. 33 the adjacent wires are reversed to make big spaces in between, while in FIG. 34 the successive wires are parallel, to make trapezoids that are (in each row) alternately inverted. The effects are different but use the same wires.
FIG. 34 also shows a wire 267 of different shape and length located between the wires 265 but attached to them with plastic coating 266. The wire 267 serves as a bounce suppressor or dampener, since having a different shape or length, its period of vibration differs from that of its adjacent wires.
FIG. 35 shows overlapped wires 270, 271 covered by a coating 272 which fastens the wires 270 and 271 together, with one wire 270 going under its adjacent wire 271, which in turn goes under its adjacent wire 273, and so on.
These are only examples of what can be done. Countless other patterns are possible.
Some Other Embodiments FIG. 36 shows the lower portion of a chair 280 having a seat 62 that is inverted with respect to FIG. 1, so that it is concave instead of convex. While generally not preferable, this structure is quite usable and gives a simple trough shape.
FIG. 37 shows a stool 285 having a seat 62 provided after installation with double curvature, by bending the frame, to provide a concave arc bent into an upper or convex arc, as seen from the side. The concave-convex seat may be made in the manner described in connection with FIGS. 20 to 22.
To those skilled in the art to which this invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. The disclosures and the description herein are purely illustrative and are not intended to be in any sense limiting.
1. A seating assembly, including in combination:
a. a frame having at least two rigidly spaced-apart rigid frame portions,
b. a series of arcuate, continuous, sinuous wires, each having two ends, each said wire closely approaching each of its immediately adjacent said wires at frequent intervals, each said wire defining a cylindrical arc,
c. retaining means for firmly securing said wires to respective fixed locations of said frame portions adjacent their ends and for preventing relative sliding movement of the wires along said frame portions, each said wire upon installation being flattened from its initial cylindrical arc to a flatter cylindrical arc and placed in tension, and
d. a thin sleevelike stretchable plastic coating being a separate member from said retaining means and surrounding said wires, retaining means and frame portions, following the sinuosity of said wires and stretchably joining said wires together where they closely approach each other, said approaches being close 'enough for effective bridging between them by said coating, whereby said wires, retaining means, frame portions, and plastic coating com prise a unitary assembly and whereby resilience for seating comfort is obtained both by the arcing and tensioning of said wires and by the strenchability 4. The assembly of claim 3 wherein said frame folds said arched seat up to nest within said arched back, with the lower surface of said arched seat then lying within the chord across said arched back.
5. The assembly of claim 3 wherein the seat and back thicknesses are each substantially less than the frame thickness and said frame is stackable upon a like frame with the upwardly arched seats nesting on each other and the rearwardly arched backs nesting on each other, so that compactness of the stack is limited to frame thickness rather than seat or back thickness.
6. The assembly of claim 5 wherein the thicknesses of the seat and back areas are no less than 1 200 and no more than 1/50 of the height of the seating assembly.
7. The assembly of claim 3 wherein the wires in the seat lying closest to the forward edge of the chair are of lighter gauge than the remaining wires of the seat, thereby imparting increased comfort.
8. The assembly of claim 2 wherein in each said assembly said wires occupy a silhouette area of about 17 percent to 75 percent of the area over which they extend so that the sitter is supported without undue load concentration.
9. The assembly of claim 2 wherein said seat arches upwardly from front to rear and said back arches forwardly from bottom to top.
10. The assembly of claim 2 wherein said frame is curved so that the seat and back are compoundly curved.
11. The assembly of claim 1 wherein some of said wires are of different natural vibration frequency than others to afford bounce dampening to said assembly.
12. The assembly of claim 1 1 wherein some wires are different in thickness from others.
13. The assembly of claim 11 wherein some wires are of different arc-cycle length from others.
14. The assembly of claim 11 wherein some wires have a different spring temper from others.
15. The assembly of claim 1 wherein said means for securing comprises friction lock means fastening each wire at each end to a said rigid frame portion and preventing withdrawal.
16. The assembly of claim 1 wherein said retaining means comprises a strip of metal secured to each said frame portion and providing a plurality of wire-end anchoring means between said strip and said frame portion.
17. The assembly of claim 16 wherein each said frame portion has a cylindrical outer surface and each said strip is a cylindrical segment having two series of projecting tongues, alternating with each other, the tongues of one series being short and lying against the surface of their said frame portion, thereby providing stop portions for ends of said wires, the tongues of the other series being longer and diverging from the surface of their said frame portion to provide space for the wire ends to lie between those tongues and said frame portion along a line parallel to the axis of said frame portion and with their ends abutting the shorter tongues.
18. The assembly of claim 17 wherein said longer tongues provide friction grip means for said wire.
19. The assembly of claim 17 having a rim member surrounding the wires at their sides and ends and enclosed by said coating with the wires.
20. The assembly of claim 17 wherein each said frame portion is cylindrical and each said strip is a cylindrical arc snug against the surface of said frame portion and having punched-out portions and bent out portions for receiving the ends of said wires along a line parallel to the axis of the frame portion, with the ends of the wires snugly against a portion that has not been punched out or bent out and that acts as a stop.
21. The assembly of claim 20 having front and rear non-sinuous rim wires secured to said frame portions by said strips and tangent to the forward and rear wires and coated with them.
22. The assembly of claim 1 wherein said frame portions are tubular and said retaining means comprises a series of holes through the walls of said frame portions for receiving bent ends of said wires.
23. The assembly of claim 22 having rim means with portions extending along said frame portions and touching said bent ends.
24. The assembly of claim 1 wherein said retaining means comprises a bent wire member separate from said series of wires and fixedly secured to each said frame portion.
25. The assembly of claim 24 wherein said bent wire member comprises a square-wave pattern with two axially-extending portions joined by alternating circumferential portions, one of which serves as a stop, the other of which is bent away from said frame portion to enable the end of a said spring wire to pass thereunder.
26. The assembly of claim 24 wherein said bent wire is bent to provide an axial portion regularly interrupted by two circumferential portions providing a channel, each for receiving an arcuately hooked portion of a said spring wire.
27. The assembly of claim 1 wherein said retaining means comprises a series of generally circumferentially extending grooves in said frame portions for receiving arcuately hooked end portions of said wires.
28. The assembly of claim 1 wherein said plastic coating has a Shore A durometer in the range of 45 to 90.
29. The assembly of claim 28 wherein said coating has a Shore A durometer of about 75.
30. The assembly of claim 28 wherein the thickness of said plastic coating is from about 20 percent to about 100 percent of the wire thickness.
31. The assembly of claim 1 wherein the wire thickness is in the range of 0.05 inch to 0.15 inch.
32; The assembly of claim 1 wherein said series of wires comprises a seat and the seat has a consistency such that it depresses between 1 inch and 3 inches when sat upon by a ISO-pound person.
33. The assembly of claim 1 wherein said series of wires comprises an upwardly arching seat having a crown height that is one sixty-fourth to one-sixteenth of the width of the seat.
34. The assembly of claim 1 wherein said series of wires comprises a downwardly arching seat, having a concave upper surface.
' 35. The assembly of claim 1 wherein the empty space between the coated wires occupies from about 2 percent to about percent of the area of the wire assembly.
36. The assembly of claim 1 wherein the series of I wires comprises a seat and the seat is compoundly curved from a concave shape.
37. A seat for a chair or sofas or the like, comprising:
two rigid frame members, held apart by one or more additional stiff frame members,
a series of sinuous spring wires extending between said frame members and secured to them at their ends, each wire touching its adjacent wires at least once per cycle.
spacing and latching means secured to each said frame member for securing one end of each of said wires to respective fixed locations of said frame members and for properly spacing said spring wires from each other, each said spacing and latching means having a receptacle for an end of 39. The assembly of claim 38 wherein said plastic coating has a Shore A durometer of 45 to enabling a two-way stretch action.
40. The assembly of claim 38 wherein said plastic coating has a Shore A durometer of about 75.
41. The assembly of claim 1 wherein the close approaching of said wires comprises overlap of the successive wires, so that while all the wires lie substantially on the same plane, they are actually in different planes at the overlaps.