US 3497262 A
Description (OCR text may contain errors)
Feb. 24, 1970 A G, plRE'r-n ETAL 3,497,262
. I STCKABLE, DISASSEMBLABLE` CHAIR Filed Nov. 27. 1967 2 Sheets-Sheet 1 Fig.1
Giancarlo PIRETTI Leonida CASTELLI ATTORNEY Feb. 24, A1970 Fnea Nov. 2v, 1967 G. PIRE-rn ETAI- STACKABLE, DISASSEMBLABLE CHAIR 2 Sheets-Sheet 2 i F196 INvENToRs Giancarl PIRETTI Le onid CASTELLI ATTORNEY United States Patent O M 3,497,262 STACKABLE, DISASSEMBLABLE CHAIR Giancarlo Piretti and Leonida Castelli, Bologna, Italy, as-
Signors to S.a.s. Anonima Castelli & C., Bologna, Italy, a limited partnership, a corporation of Italy Filed Nov. 27, 1967, Ser. No. 685,768 Claims priority, application Italy, Sept. 12, 1967, 39,370/ 67 Int. Cl. A47c 3/04, 7/70, 1/24 U.S. Cl. 297-239 5 Claims ABSTRACT 0F THE DISCLOSURE A stackable chair having a pair of inner solid members of die-cast light-metal alloy supporting the head and back, and a pair of outer solid die-cast light-alloy elements in which the legs are received. The inner and outer elements on each side of the chair are generally elongated in the horizontal direction of the respective side of the chair and are provided with mating longitudinal groove-andridge formations and are interconnected by a bolt and expandable-sleeve assembly traversing the inner and outer elements. The outer element on each side of the chair forms, at its upper side, a rest for the underside of the corresponding element of a chair adapted to be stacked thereon, while the other elements also are provided with grooves adapted to receive connecting pins for holding a number of chairs in laterally adjoining relationship to form a row.
The present invention relates to a chair mainly intended for public premises for meetings and work, theater pits and amphitheaters in general, economicoperational premises, oflices and the like, and consisting mainly of light-metal die-cast elements, so designed that, when interconnected, they can be assembled with four screws only, which lock and strongly fix in their proper positions the back and the seat of the chair without requiring the use of supplementary screws, supports, glues, mastics or other traditional systems.
OBI ECT OF THE INVENTION It is the object of the present invention to provide an improved, readily assemblable seating unit having considerable structural strength and rigidity and a minimum number of parts.
The chair of the present invention, as described below, is of simple assembly and easily disassembled and it is so designed that the die-cast elements supporting the legs allow an easy lateral coupling or connection to another like chair on both sides, so as to permit the joining of chairs in a row; furthermore on the outside face of the die-cast elements supporting the legs, it is possible, using the same four screws used for the assembly, to attach, at least on one side of the chair, a bracket supporting an arm or a small wooden block, to be used as writing desk or as a rest, xed to a metal bracket enabling tilting, e.g. a hinge incorporated in the bracket.
The chair, with or without the above-mentioned lateral brackets, can be overlapped without limit and, therefore, it is possible to pile a number of chairs in a minimum possible space.
SUMMARY OF THE INVENTION The chair, according to the invention, consists of at least four die-cast elements of Va light-metal alloy, of
3,497,262 Patented Feb. 24, 1970 ICC i.e. the inside faces, longitudinal grooves adapted to receive corresponding projections formed along the lateral edges of the back and the seat of the chair; the diecast elements are rigidly joined two-by-two, by at least one tubular cylindrical bush or sleeve with slightly conical walls, which bush or bushes are directly inserted at the time of die-casting in the element supporting the legs.
At least one rigid tubular frame connects the coupled die-cast elements, having at least four ends free, in which are received conical locking devices capable of expanding and which can be tightened by means of screws from the outside of the above-mentioned die-cast elements.
'Ihe chair of the instant invention also includes a back or a seat, either separately or together with lateral edges whose projections can be inserted into grooves formed in the above-mentioned die-cast elements.
Furthermore the die-cast elements supporting the legs have on the external side of the chair at least an opening facing a recess casing received in the die-casting, the opening being designed to receive a coupling device for interconnecting the chairs in rows, the device is made of metal, plastic, synthetic resin) material or the like, and on the inside is provided with holes or slits suitable to support hooks, brackets or attachments of any sort for accessories such as paperholding baskets or planes on which can be located things with a limited surface.
The bracket, supporting either an armrest for the person seated on the chair or a desklike tiltable wooden plate or in general some other plate, is fixed on the outer side of the die-cast element supporting the legs by using the same screws which are used for assembling the chair without the brackets, these screws should be long enough to extend beyond the bracket thickness and screw in to the female thread of the expanding conical locking device.
SPECIFIC DESCRIPTION The invention is described below with reference to the drawing in which:
FIG. l shows, in a side view, a chair with the bracket supporting a tilting wooden planar writing desk and a paper-holding basket;
FIG. 2 shows, as seen from the front, the chair of FIG. 1;
FIG. 3 shows a detail of FIG. 2, enlarged;
FIG. 4 shows, as seen from the top, the detail of FIG. 3;
FIG. 5 shows, in a side view, a coupling device between the chairs according to the invention; and
FIG. 6 shows, as seen from the top, the device of FIG. 5.
The chair shown, includes two die-cast main elements 11 of light metal alloy, perfectly identical to one another, each element having therein inserted by imbedding at the time of die-casting, on one side, turned toward the door, two steel tubes forming the legs 12 (covered with plastic material 13 and with adjustable feet 14). On the other side, transversely and turned toward the chair inside, the chair is provided with two tubular bushes 15, with slightly conical section walls, passing through corresponding holes of the die-cast element 17, which are (mirror symmetrical) specularly alike and each of which is coupled to one of the leg-supporting elements 11.
Each bush 15 is machined or, better, bored round the inside edge of its own hole so that the die-cast elements 11 and 17, fitting perfectly one to the other along the joining surface shaped as a tooth or step, will be rigidly and indissolubly connected (see FIG. 3), to form the right or left support of the chair; the axial hole 0f bush 15 is open for the entire length of the bush and is accessible at the faces of elements or pieces 11 and 17 that have remained free.
On the counter-posed surfaces of the die-cast elements 17 which are specularly alike, that is to say that the right-hand element is mirror symmetrical to the left-hand element, we provide extended longitudinal grooves adapted to receive the projections 19 along the lateral edges of the seat 30l and back 21; the latter consist of plywood bodies bent into anatomical shape. The joining element between the right and the left supports of the chair, each formed by the rigid coupling of the respective elements 11 and 17, consists of a frame realized with two sections of steel tube 23, curved according to the lower profile of the seat and connected rigidly by means of cross-pieces 24, which are welded or riveted. The frame has at its four free ends locking and expanding conical devices 25, of wellknown type, which are inserted into the axial holes of the bushes 15 from the interior of element- 17 and can be tightened from the exteriorY of element 11, by means of screws 27 which screw into the axial thread of the expansion cone 27 (FIGS. 3 and 4) of the device 25.
When the four screws 26 are screwed in, after inserting projections 19 of the seat 20 and back 21, into the grooves 18 of the elements 17, one then establishes the traction and locks the conical expansion devices of the frame and, consequently, fully tightens all the pieces comprising the chair.
The die-cast elements 11 have, on the lower edge of the outer side of the chair, a recess 28 (FIG. l) of rectangular shape with the longer side arrested vertically, such opening being the transversal free-section of a groove, produced in the piece at the time of die-casting. The opening is provided with a cylindrical enlargement 29 having a diameter slightly larger than the width of the groove 28 and a depth of a few more millimeters, which on the part exceeding in depth is smaller in diameter and threaded. The recess formed by the groove 28 followed by the cylindrical enlargement .29, is adapted t0 receive the half of the joint piece 30` (FIGS. 5 and 6) which forms the lateral connecting or coupling means between two side-by-side chairs; the other half of the jointpiece 30 is held in the similar recess in the other chair to be connected. The length of the joint-piece 30 is such that, when set, can exert a slight traction, so that the adjacent faces of the side-by-side chairs are forced against each other. One of the two cylindrical ends of the piece 30, that is to say the one with a larger diameter, has a hole 30 to allow the passage of the screw 31, which is threaded into the deeper part of the cylindrical casing 29.
The same die-cast elements 11 have, on the surface towards the inside of the chair, two holes 32 (FIG. 2) into which can be inserted the outwardly bent pins of brackets 33 for hooking a paper-holder basket 34 onto the chair; on the lower surface another two holes are provided in which are inserted nylon mufiiing caps 36, which are useful as cushions when the chairs are stacked one over the other, such that the legs and outer light metal elements 11 of the stacked chairs are in respective planes. In the nonlimiting example shown, the chair is shown to have a bracket 37 supporting the woodenplane writing desk 38 on the right-hand side. Bracket 37 for this desk consists of a tubular light-metal alloy die-cast element with two circular holes (at one end) which overlap those of element 11, traversed by two tightening screws 26, as well as a recess identical to that formed by the groove 28 and the cylindrical enlargement 29, and at the opposed end the hinges 39, formed at the time of die-casting, into which are inserted the pins 40 of the hinge which permits the tilting, within certain angles or fixed limits of the plate which supports the Wooden desk 38. The bracket 37 which supports the wooden desk 38, is identical in its lower part to that which supports the arm and is applied on the external face of element 11 using the same screws 26 needed for the tightening of the chair, such screws being long enough to traverse the thickness of the bracket and screw into the thread of cone 27 of the expansion locking device 25. To avoid transverse oscillations, the bracket 37 is fitted with a tooth 42 (formed at the time of die-casting) identical to one half of the joint piece 30 which at the time of the assembly notches in, exerting a slight traction in groove 28-29 of element 11 so that the bracket 37 remains rigidly connected to the other elements of the chair, forming with them an integral body.
When bracket 37 is not used, the joint piece 30 will have a suiiicient length to be locked, by a slight traction, into grooves 28-29 of the corresponding elements 11 belonging to two side-by-side chairs.
The legs inserted into each element 11 form an acute angle, whose vortex is Vat the top, such that the top surface of each element 11, projecting from element 17 coupled, can offer a support to the muffiing caps 36 on the lower surface of a chair overlapped with the first, since the lower profiles of elements 17 and 37 of the stacked overlying chair are al1 contained within the outline of the corresponding elements of the chair underneath; brackets 37 `are inclined towards the outer part of an angle so that the inside profile of the object to be supported by them, in a position of minimum horizontal surface (desk lifted), falls entirely out of the vertical plane tangent to the external surface of element 11. Such angles and profiles permit stacking of the chairs, also when they are fitted with the accessories 37.
What is claimed is:
1. A stackable chair comprising a pair of generally horizontally elongated inner elements adapted to lie along opposite sides of a seating surface and composed of a diecast light-metal alloy and of generally solid cross-section; a pair of generally elongated outer elements die-cast of a light-metal alloy and of generally solid cross-section respectively juxtaposed with said inner elements, the inner and outer elements along each side of said seating surface being provided with mating longitudinally extending groove-and-ridge formations preventing mutual transverse displacement of the elements at each side of said seating surface; detachable connecting means including a pair of longitudinally spaced expansion members in one of the mating elements at one side of said seating surface and a respective screw traversing the oher element of each side and anchored in each of said expansion members and tightenable to clamp the elements on each side of said seating surface together; a pair of legs anchored in and extending downwardly from each of said outer elements; and a seat structure mounted on said inner elements and bridging same while forming said seating surface, said seat structure including at least one pair of tubular frame members spanning said inner elements and anchored thereto.
2. A chair as defined in claim 1 wherein said inner elements are each formed with a pair of transverse bores each receiving one of the tubular frame members and a respective expansion member whereby said expansion members clamp said tubular frame members to said inner elements and the inner and outer elements of each side of said seating surface together upon tightening of said screws, said outer elements each being formed with laterally open notches alignable with corresponding notches of adjoining substantially identical chairs, each pair of adjoining chairs being provided with a connecting member receivable in the notches of the respective outer elements.
3. A chair as defined in claim 2, further comprising a bracket mounted on the outer element on at least one side of the chair, said bracket and the outer element on which it is mounted being formed with mating tooth-and-notch formations preventing twisting of the bracket with respect to the outer element on which it is mounted, said bracket being traversed by the said screws traversing the outer element on which the bracket is mounted; and a writing desk swingably mounted on said bracket.
4. A chair as defined in claim 2 wherein the legs of each pair extend downwardly while including an acute angle with one another, each of said outer elements being formed with a generally horizontal upper surface between the legs of the respective pair and a lower surface provided with muiing caps adapted to rest upon the upper surface of a corresponding outer element of a generally identical chair therebelow in a stacked condition of said chairs.
5. A chair as defined in claim 4 wherein said seat structure comprises a shaped wood seat and a shaped wood backrest spanning said inner elements, said inner elements having upwardly and rearwardly extending arms carrying said backrest said frame members being interconnected intermittent said elements, said legs being generally tubular and having a covering of synthetic-resin material, said chair further comprising self-adjusting feet on said legs.
References Cited UNITED STATES PATENTS 3,156,498 11/ 1964 Blodee 297-162 3,227,487 1/ 1966 Blanchard 297-248 3,237,984 3/1966 Schneider et al 297-248 3,281,184 10/1966 Axtell 297-248 3,328,075 6/ 1967 Albinson 297-248 FOREIGN PATENTS 974,861 11/1964 Great Britain.
703,439 2/ 1931 France.
958,505 2/ 1957 Germany.
JAMES T. MCCALL, Primary Examiner U.S. Cl. X.R. 297-162, 248