US 3206251 A
Description (OCR text may contain errors)
Sept. 14, 1965 J. G. STEVENS CHAIR STRUCTURE AND METHOD FOR MAKING SAME Filed June 1'7, 1963 3 Sheets-Sheet l JOEL e. STEVENS INVENTOR.
ATTORNEYS BY Iu LL Sept. 14, 1965 G. STEVENS 3,206,251
CHAIR STRUCTURE AND METHOD FOR MAKING SAME Filed June 17, 1963 3 Sheets-Sheet 2 JOEL G. STEVENS INVENTOR.
m'm rm ATTORNEYS Sept. 14, 1965 J. a. STEVENS CHAIR STRUCTURE AND METHOD FOR MAKING SAME Filed June 17, 1963 3 Sheets-Sheet 3 FIG FIG .9
JOEL G. STEVENS INVENTOR.
ATTORNEYS United States Patent 3,206,251 CHAIR STRUCTURE AND METHUD FUR MAKING SAL IE Joel G. Stevens, 5006 41st SW., Seattle, Wash. Filed June 17, 1963, Ser. No. 288,3tl8 4 Claims. (Cl. 297-457) This invention relates to a new and novel chair structure and method for its making, and more particularly to a chair structure and method directed to a chair shell made of fiat, relatively thin, sheet material and which does not have a supported back but which does not have a supported back but which depends on its naturally formed curves for strength and flexibility.
Many, if not most, of the chair shells which are known today are singularly complex devices. Their designs and hence their manufacture is involved and expensive. For instance, compound and other artifically formed curves require molding and forming equipment usually found in elaborate production lines. The nature or" the hitherto known designs also necessitates specially designed leg structures. In most of the other types and designs with which applicant has become familiar the leg structure for the chair has also employed a support for the back portion of the chair shell. With no support a one piece, rigid molded and nonfiexible shell usually requires specially designed leg mountings to achieve and flexibility in the structure as a whole. Apparently it has been assumed in all cases that a back support for the chair shell is necessary.
This invention is designed to provide a chair shell and the method for its making which represent a significant advance in the chair manufacturing industry. This invention overcomes numerous of the disadvantages of other chairs because of its extreme simplicity. In essence, this invention involves cutting a predetermined pattern design from a piece of sheet material, slitting the sheet or the pattern at a predetermined location, and then overlapping the portions on each side of the slit to draw the pattern into a natural or free form configuration around the inside end of the slit. Such structure and method result in the formation of a form which most closely resembles a cone generated generally around the inside end of the slit or cut. In any event there are no obvious stress points or areas which would, and which usually do, result from artifically formed curves. The formed single sheet pattern is attached to practically any kind of leg structure which does not involve means for supporting the back portion of the chair shell. The overlapping, intended primarily for the seat, increases the chair strength twofold in an area which might otherwise not be strong enough. At the same time the back and sides, being formed of single thickness material, are more fiexible than the seat which is precisely the result desired.
Accordingly it is one of the many objectives and purposes of this invention to provide a chair incorporating a maximum of design balance, comfort and strength.
Another object of this invention is to supply a chair which is simple in design and to which many, if not most of the conventionally known leg structures can be adapted.
A prime object and purpose of this invention is to furnish a chair structure and method for its making which because of design simplicity requires no complex, costly time consuming production equipment and which is therefore extremely inexpensive to produce.
Another object of this invention is to provide a chair structure and method for its making which, in utilizing the natural curves of a cone, enable an infinite number of design variations on the basic concept by changing the pattern layout.
3,206,251 Patented Sept. 14, 1965 ice Still another object of this invention is to supply a chair structure which is light in weight and which can be partially finished so as to provide shipping advantages in reduced weight and compact packaging.
Yet another object of this invention is to furnish a chair structure which is rugged and durable even though made of thin sheet material and even though it lacks supporting means for the back portion of the chair shell.
A further object of this invention is to provide a chair structure and method for its making in which the comfort characteristics are derived from the fact that the user does not need to distribute his body in the chair to accommodate the chair design, but which allows the chair to flex and adjust itself to the body of the user.
These and other objects and advantages will become apparent upon reading the following specification, claims and accompanying drawings, all of which form a part of this disclosure.
In the drawings:
FIGURE 1 is a view in perspective of a chair shell formed according to this invention which for purposes of illustration only has been shown to be mounted on a pedestal type base or leg structure;
FIGURE 2 is a side view of the chair of FIGURE 1 which also illustrates that the angle of the chair back in relation to the chair seat may be varied considerably;
FIGURE 3 shows how a pattern for this invention may be laid out in its purely flat state;
FIGURE 4 shows a side view of a chair which may be formed from the pattern of FIGURE 3, and which for purposes of illustration shows a different leg structure;
FIGURE 5 shows an alternative pattern in which the point at the back of the chair seat is de-emphasized by making a diiferent cut in the pattern;
FIGURE 6 shows in perspective what a chair formed from the pattern of FIGURE 5 would look like;
FIGURE 7 shows how emphasis may be taken off the point at the rear of the seat depending upon the nature of the cut at the inner end of the slit;
FIGURE 8 shows a difierent pattern in which the chair back is slit in order to form a double back instead of a double seat;
FIGURE 9 shows a chair formed from the pattern of FIGURE 8 and suggests along with FIGURE 8 the extreme flexibility of the method involved in this invention;
FIGURE 10 illustrates a side view of a single piece pattern which could be designed to include the secondary cone structure at the top of the chair shell back for shade or for holding a reading light, if desired; and
FIGURE 11 shows a front view of an alternative embodiment formed basically from the pattern of FIGURE 3 but in which the seat has been flattened rather than allowed to follow the natural curves generated around the point at the back of the seat.
Referring now to the drawings, it will be seen that the chair shell, generally designated by the number 10, is cut to a predetermined pattern from a sheet of flat, relatively thin material such as aluminum or resin reinforced fiberglass. Either of these materials can be used, although the plastic shell should use a pattern with a fairly large hole at the inner end of the seat. The thickness of the sheet material takes no definite or specific dimensions. However, it has been found that .030 gauge tempered aluminum sheet has been incorporated very favorably in those chairs already produced. Likewise a plastic shell, which besides fiberglass, could include a wide range of plastic material would be in the area of about /s of an inch thick. The seat portion, as can be seen witth reference to FIGURE 4, flares outwardly and away from the general area at the base of the back portion 12 in the form of reverse curve edge portion 42.
The edge portion 42 terminates at points 44. A generally semi-circular edge as at 38 and 46 is cut from one point 44 to the other point 44. Curvative of the edges 38 and 40 is determined by the fact that those portions of the chair shell defining said edges will overlap and must therefore place said edges as close together as possible.
The pattern can be considered as symmetrical on each side of a longitudinal axis running along a center line taken through the back and seat portions. When the pattern has been out along the general lines mentioned above a hole 34 is cut at a predetermined point on the longitudinal axis at a predetermined distance from the front edge of the seat. The pattern is slit from the front edge to the hole along said axis to define the seat section 18 with a slit edge 20 and a seat section 22 with a slit edge 21. Thus seat section 22 has front edge 49 while seat section 18 has front edge '38. The hole '34 may be of any size and therefore its dimensions are not to be considered limiting. The purpose in deemphasizing the point of the chair with a larger hole, as in FIGURE 7, is to reduce possible injurious effects by reducing the projection of models with little or no covering. Also for chairs left outside, moisture and rain are easily drained oft. For purposes of illustration a hole 34 one inch in diameter may be cut on the longitudinal axis sufficiently far from the front edge of the seat to provide adequate =body support or seat area and yet at the same time to allow for the fact that the body will not occupy a space of several inches which is most immediate to hole 34-. As can be seen by reference to FIGURE 3, the hole may be larger and of a shape other than round as indicated by the hole 36 in dotted lines. Hole 36 is given the illustrated shape so as to present a curved side view rather than a straight line side view thus avoiding abrupt edges.
When the pattern has been cut and slit as indicated one seat section, as for instance 18, is drawn over and lapped on the other seat section 22. As a result of this overlapping the pattern will dr-aw itself into natural curves around the hole '34 which, in effect, is the point or apex of a cone. In theory all curves are generated in the form of a perfect cone. As practical matter, however, the curves are not perfect but do very closely resemble natural cone curves. The overlapping of sections 18 and .22 is limited in the extreme by the desire to have an angle of no less than 90 degrees between the back and seat surfaces. However, it is best not to overlap to such an extent that the seat and the back achieves such an angle to each other. When the desired angle between the seat and the back has been realized, four holes are drilled or formed through the overlapping seat sections 18 and 22. As can be seen, particularly with reference to FIGURE 1, two holes are drilled near the slit edge '20 of top seat section 18 and two holes are drilled or otherwise formed near the underside slit edge 20 of seat section 22. Two
holes are located near the front edge of the seat While two holes are drilled relatively close to hole 34. Securing means 24 and 26 and 28 and 29 are inserted through the holes to hold the seat sections in their overlapping relationship and to secure the entire seat shell or pattern 10 to the leg structure which for purposes of this illustration has been shown to be pedestal 32.
The leg structure or chair shell supporting structure is contemplated only in its broadest and most encompassing meaning. Once the overlapping has been achieved, the holes formed and the securing means inserted through the holes and into the base or leg supporting structure, the chair is essentially completed. It is only necessary then to use a proper hand tool to de-burr and to round the edges and to do whatever finishing is desired. This particular chair shell lends itself very readily to upholstering with any kind of material from a thin fabric to a thick foam rubber or other cushioning type covering. Any type of covering or upholstering is easily provided by simply cutt ng it to the shell pattern. Stretching and pulling are avoided and the problems of accommodating the covering to compound curves and irregular lines and surfaces are also not encountered. Thus adhesives may be used very effectively.
FIGURES 5 and 6 suggest a way in which the sharp point effect of a small hole 34 may be eliminated by a slightly different cut in that area of the pattern surrounding the inside end of the slit. A pattern 50 has a back portion 51 and a seat area which is generally in agreement with the outlines of pattern 10. The slit is made defining slit edges '54 and 56 but terminating as at 52 at a predetermined point on the longitudinal axis. At a point several inches from the terminal end 52 of the slit a circular cut is made extending in a generally round curve for approximately 270 degrees or a circle. The cut or slit 62 is made with terminal end 52 as the generating center thus defining the center section 64 which is still integrally connected to the overall pattern. When this alternative structure is finished with the seat sections overlapping the center section 64 has cut off a larger portion of the point of the cone than the one inch hole. The center section 64 in effect itself assumes a slightly conical shape around terminal end 52. This particular pattern shows some of the flexibility that is connected with the use of this method and structure. The pattern or chair shell 59 can be attached to the leg structure 66. If desired the outer ends of the seat slit may be rounded oil as 58 and 69 for aesthetic reasons, and to eliminate sharp projections so that the lapped portions slide more easily into place.
FIGURES 8 and 9 indicate that the pattern may have a double thickness on its back portion if desired to strengthen the back or mount something thereon. Note that in pattern 7 (9 there are two back sections 74 and 76. Hole 82 is formed in the pattern on the longitudinal axis thereof and a slit is made from between the two back sections to said hole 82. The seat portion 72 is designed to its finished shape as the back section 12 is in pattern 10. Note that slit edges 78 and Sit in the finished chair extend from the point generally upwardly and outwardly to the transition curve between the seat and back portion. Finally the completed chair shell is secured to a leg supporting structure 84. The extra variability of design indicated by these two figures gives a chair shell with seamless seat and side portions. The double thickness back allows the shell to be fastened to a wall for stationary use.
FIGURE 10 shows further the versatility of the free form cone design. A pattern 9t) has aform similar to that of pattern It) but also has a hood section 92 formed around a hole at point 94.
FIGURE 11 shows that the seat of pattern 10 may be flattened if preferred to the natural curve. Some forming would then take place in the seat portion as at 9.6 and 98 in the area next adjacent to slit edges 20 and 21.
This invention, particularly as shown in FIGURES 1 to 7, l0 and 11 provide a chair which allows a maximum of free movement to its occupant. Thus, side-toside, back-and-forth, and twisting motion are permitted the user. The amount of movement allowed can be controlled by leverage due to the height of the back, angle of tilt of back with respect to the seat, and by the extent of overlap in the seat.
The foregoing is considered as illustrative only of the principal of this invent-ion and hence it is not desired to limit the invention to the exact structure and method shown and described. Accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
What is claimed is:
1. A chair structure, comprising: a chair shell made of a single sheet of flat, relatively thin, essentially rigid material, said shell being formed from a pattern in which sections of said patterns are overlapped to define a double thickness seat area leaving the side portions adjacent said seat area and the back portion of said shell in single thickness, said shell being formed on natural, essentially conelike curves around a hole means centered with respect to the side edges of said shell and from which hole means said seat, side portions and back portion are generated; and a chair shell supporting structure attached to said shell by securing means designed to be inserted through said double thickness seat portion for maintaining said double thickness seat, said supporting structure being entirely free of means for supporting said back portion of said shell.
2. A chair structure, comprising: a chair shell made of a single sheet of fiat, relatively thin, essentially rigid material, said shell being formed from a pattern in which sections of said pattern are overlapped to define a double thickness seat area leaving the side portions adjacent the seat area and the back portion of said shell in single thickness, said shell being formed on natural, essentially conelike curves around a hole means centered with respect to the side edges of said shell and from which hole means said seat, side portions and back portion are generated; and a chair shell supporting structure attached to the underside of said shell by securing means, said securing means being inserted through said double thickness seat and said supporting structure being entirely free of means for supporting said back portion of said shell.
3. A chair structure, comprising: a chair shell made of a single sheet of flat, relatively thin, essentially rigid material, said shell being formed from a pattern having a back portion, a seat area and side portions adjacent said seat area, said pattern having sections which are overlapped to define a double thickness seat area leaving the side portions adjacent the seat area and the back portion of said shell in single thickness, said shell being formed on natural, essentially cone-like curves around a hole means centered with respect to the side edges of said shell and from which hole means said seat, side portions and back portions are generated; and a chair shell supporting structure attached to the underside of said shell by securing means inserted through said double thickness seat portion, said supporting structure being entirely free of means for supporting said back portion of said shell.
4. A chair structure, comprising: a chair shell made of a single sheet of flat, relatively thin, essentially rigid material, said shell being formed from a pattern in which sections of said pattern are overlapped to define a double thickness back area leaving the side portions adjacent the seat area and the seat portion of said shell in single thickness, said shell being formed on natural, essentially cone-like curves around a hole means centered with respect to the side edges of said shell and from which hole means said seat, side portions, and back portion are generated; a chair shell supporting structure attached to the underside of said shell by securing means; and securing means inserted through said double thickness back; and said supporting structure being entirely free of means for supporting said back portion of said shell.
References Cited by the Examiner UNITED STATES PATENTS 401,302 4/89 Purdy 297-445 2,541,835 2/51 Saarinen 297-457 2,606,601 8/52 Saarinen 297418 2,939,517 6/60 Saarinen 297-418 3,009,740 11/61 Nelson et a1. 297457 FRANK B. SHERRY, Primary Examiner.