Three Position Folding Seat

Abstract

A folding chair has a rectangular outer frame in which a U-shaped inner frame is received. A flat seat is received within the inner frame with the seat and two frames all relatively pivotal about a common axis. Stops are provided at the axis to allow the seat to pivot relative to the inner frame from a position coplanar therewith to a position extending at an angle thereto. The U-shaped inner frame can, in turn, pivot from a position coplanar with said outer frame to a position extending at an angle thereto. In this manner the seat can be raised out of the down, use position while the base of the chair remains open and the chair remains standing for storage of the chair or passage of someone past the chair in a cramped aisle. The pivots are completely contained between the frames and seat at the axis so that the chair only has three independently movable pieces.

Description

The present invention relates to a folding seat designed to take three pre-established positions. This seat, according to our invention, is substantially constituted of a pair of frames having a substantially rectangular shape, one of which is wider than the other so that this latter may be located within the first one, and of a U-shaped frame, so proportioned that in the closed position of the seat said U-frame can enter between said greater and smaller rectangular frames. The rectangular and U-shaped frames are articulated relative to each other by means of articulated joints, each connecting intermediate points of the longitudinal members of the rectangular frames and the end of one of the parallel legs of the U-shaped frame, which joints are each located to one of the sides of the seat. The articulated joint comprises joint elements each respectively integral with one of said three frames, and comprising projecting parts in form of a sector of a circle which are designed to be received in annular guiding grooves provided in the facing surfaces of the adjacent joint elements. The sector-like projecting parts each have an angular length less than that of the co-operating annular groove so as to allow the three frames to perform mutual rotary movements of pre-determined angles about a common pivot axis and to stop respectively in three pre-established positions of the seat. After assembling of the joint elements, these latter are connected to each other by means of supporting busches which are respectively integral with one of said rectangular frames and which are connected to screws respectively supported by the other rectangular frames.

It will be obvious that the structures and materials which are employed for the construction of the three frames must be adapted to enable the seat to resist the forces acting on it and due to the weight of the seat as well as of the user and/or to the loads which can be expected to be applied to it.

Other characteristics and advantages of the present invention will be more apparent upon consideration of the following description of an embodiment which has been given merely by way of example, taken in consideration with the accompanying drawings, in which:

FIG. 1 is a front view of the seat in its closed position;

FIG. 2 is a perspective view of the seat in its open position;

FIG. 3 is a side view of the seat in the intermediate position;

FIG. 4 is an exploded perspective view of the joint elements integral with the side members of the three frames and which are parts of the articulated joint, the joint shown here being to the right side of the seat as viewed in FIG. 1;

FIG. 5 is an exploded perspective view, similar to that of FIG. 4; but showing the same joint elements as seen in the opposite direction; and

FIG. 6 is a detail view, in enlarged scale, of the articulated joint shown in FIGS. 4 and 5, illustrated in an axial section and in the closed position of the seat.

The joint elements constituting the articulated joint on the left side of the seat will be of course symmetrically identical to those which form the articulated joint on the right side of the seat and which are shown in the FIGS. 4 to 6.

As can be seen in FIGS. 1 to 3, the folding seat which is the object of the invention comprises two substantially rectangular frames 7 and 8 which are pivotally connected to one other in intermediate points of their longitudinal members and to the ends of the parallel legs of a U-shaped frame 9 by means of articulated joints generally marked 10 and 10' in FIGS. 1 to 3. The portion of the frame 7 below the joints 10 and 10' is slightly longer than that which is above said joints, the frame 7 constituting with its horizontal transverse member the forward bearing means for the seat. The upper portion of frame 7 carries the back 11, which may be shaped in any suitable manner, but it preferably occupies only the upper part of the space defined by the frame 7 in order not to hinder the backwards pivoting of the frame 8 carrying the sitting plane 8' as the seat is folded up into closed position and the frame 8 is positioned within frame 7.

In the use position of the seat, the U-shaped frame 9 forms with the lower part of the frame 7 a unit which in side view looks like a compass, the angle between frames 7 and 9 being preferably 55.degree.. The transverse member of the U-shaped frame 9 constitutes the rear bearing means for the seat, while as the seat is placed in its closed position (FIG. 1), the frame 9 is placed in the same plane as the frames 7 and 8, thereby lying inside the frame 7 and outside the frame 8.

Of course, the size of the angle formed between the U-shaped frame 9 and the rectangular frame 7 in the open position of the seat, which has been hereabove assured to be of 55.degree., could also be of any different value, as less or more inclined seats are desired.

In the intermediate position, shown in FIG. 3, the frame 8 and the sitting plane 8' carried by this latter are made coplanar with the U-shaped frame 9 and therefore frame 8 will form in this case an angle with the frame 7 which is equal to that which is formed between the frame 9 and the lower part of the frame 7, namely in the illustrated embodiment an angle of 55.degree..

When the seat components are placed in the intermediate position shown in FIG. 3, seats constructed according to this invention and which have the same dimensions can be inserted advantageously into each other so that they can be stored in a very reduced space without any risk that the rows of seats can be overturned, since the seats can stand by themselves, because they always rest on their bearing means. It will be understood from FIG. 3 that in the intermediate position the frame 9 of one seat can pass over and across the lower part of the frame 7 of another seat without meeting any obstacle, until the corresponding elements and the plane comprising the frame 9 and the sitting surface 8' of each of the adjacent seats will be brought into contact with each other. It can be also easily understood that, after a seat has been inserted into another, the forward and rear bearing means of each seat always remain steadily in contact with the ground.

To such an important advantage of the seat of this invention another advantage must be added, which is also of a considerable importance and which is that it is possible to let the seat of the invention pivot from its open position (FIG. 2) to the intermediate position (FIG. 3), where the frames 7 and 8 each form with the frame 9 an angle of 55.degree. , without any displacement of the bearing means or lower transverse members of the frames 7 and 9 relative to each other. This is advantageous in the case where very narrow rows of juxtaposed seats are provided, as often happens in meeting halls, since it facilitates passage to the public without necessitating any change in the position of the seat row, which, on the contrary is not possible when prior art folding seats are employed.

The three positions of the seat, which correspond to those which are illustrated in FIGS. 1 to 3 respectively, as well as the connection of the assembled parts is realized by the articulated joints 10, 10', pivotally arranged on a common axis and which are constituted by the joint elements 10a, 10b, 10c and 10'a, 10'b, 10'c respectively, these latter being symmetrically identical and mounted on the other side of the seat with respect to the preceding ones. The joint elements are respectively integral with the longitudinal members of the frames 7 and 8 and with the ends of the two parallel legs of the frame 9.

With reference to the FIGS. 4 to 6 will be now described the articulated joint 10 and its joint elements which are provided at the right side of the seat, as viewed in FIGS. 1 to 3, but it will be obvious that the description of the symmetrical articulated joint 10' would be the same and therefore it will be omitted.

The joint 10 comprises in combination a joint element 10a integral with the frame 7, a joint element 10b integral with the frame 9, and a joint element 10c integral with the frame 8. The element 10a has an outer surface 12 closed and flat as that of the outer side of the longitudinal member of the frame 7, while at the opposite side a recess 13 is arranged shaped as a semi-circular groove, the ends 14 of which are placed in a substantially diametral plane which is parallel to the plane of the frame 7. Further the element 10a extends inwardly with a hollow shaft or bush 15 having an internally threaded bore, the axis of which constitutes the pivot axis of the seat, namely the pivot axis of the three frames 7, 8 and 9 relative to each other. About bush 15 are pivotally mounted the joint elements 10b, 10c. The joint element 10b is integral with the adjacent end of one of the two parallel legs of the U-frame 9 and is provided with an axial hole 16 of a diameter slightly larger than the outer diameter of the bush 15 which passes through it. At the side of the joint element 10b facing the element 10a, element 10b is provided with a projecting part 18, shaped as a sector of a cylindrical ring forming an angle of about 55.degree., one of the radial end surfaces of which is marked 17 and is placed in a plane parallel to the plane of the frame 9, with which the element 10b is integral. The annular projecting part 18 in the assembled position is received in the groove 13 so that, as the seat is pivoted into its closed position, the end surface 17 of projecting part 18 abuts against the ends surface 14 of the groove 13, in which the projecting part 18 can rotate through a pre-established angle, namely in the shown embodiment through an angle of 55.degree., until the other end surface 19 abuts against that portion of the end surface 14 of the groove 13 which is positioned at the opposite side of the bush 15, so that the projecting part 18 and the groove 13 co-operating one with the other, define in combination the open position of the legs of the seat as well as their closed position, if either the surface 17 or 19 stops against the end surface 14 of the groove 13. At the side of the element 10b facing the element 10c, the element 10b is provided with a semi-circular groove 20 identical to the groove 13 and having the same orientation with respect to the longitudinal plane of the frame 9. The groove 20 is designed to receive a projecting part 22 having the same form and disposition as the projecting part 18, so that the part 10c can rotate through an angle of 55.degree. with respect to the part 10b in one direction, until the radial end surface 23 stops against the surface 21 of the groove 20, while as the element 10c rotates in the opposite direction the end surface 24 will abut against the other part of the end surface 21, the radial end surfaces 23, 24 of the projecting part 22 thus defining the two end positions of the sitting plane 8, 8' with respect to the frame 9, namely the positions shown in FIGS. 2 and 3 respectively. Besides the projecting part 22, the joint element 10c is provided with a short axial hole 25 of a diameter equal to that of the hole 16 and designed to house the end of the bush 15. The hole 25 opens into a wider hole 27, open at the outer side of the element 10c and provided to receive the head 28 of a screw 29 engaging with the inner threaded surface of the bush 15 in order to connect the parts forming the articulated joint 10. The screw 28 and bush 15 in combination with the corresponding elements of the symmetrically positioned joint 10' perform the connection of the parts constituting the structure of the folding seat. The confronting surfaces of the joint elements 10a, 10b, 10c of the articulated joint 10, are provided with annular facing shoulders 30 of equal diameter, which are designed to receive rings 31 made of plastics material and provided for the purpose of spacing apart the joint elements from each other so as to reduce the friction between the parts and to make easier the opening and closing of the seat.

Claims

What I claim is:

1. A folding chair comprising:

an outer frame having a lower end and an upper end;

an inner frame within said outer frame and having a pair of sides;

a seat within said inner frame; and

pivot means defining a pivot axis passing through said outer frame intermediate said lower and upper ends, through said inner frame at said sides, and through said seat, said pivot means including

first stop means at said axis between said outer frame and said inner frame for pivotal movement of said inner frame relative to said outer frame only between a first position parallel to said outer frame and a second position extending at an angle to said outer frame, and

second stop means at said axis between said inner frame and said seat for pivotal movement of said seat relative to said inner frame and independent of the position of said inner frame relative to said outer frame only between a first position parallel to said inner frame and a second position extending at an angle to said inner frame.

2. The chair defined in claim 1 wherein said seat includes a seat frame, said stop means each including an axial projection on one of said frames and a recess on another of said frames receiving said projection.

3. The chair defined in claim 2 wherein said pivot means further includes a pair of bushes lying on said axis and each connected to one of said seats and outer frames.

4. The chair defined in claim 3 wherein said stop means each includes a synthetic-resin ring extending axially between two of said frames.

5. The chair defined in claim 1 wherein inner frame defines in said second position an angle of substantially 55.degree. with said outer frame.

6. The chair defined in claim 1 wherein said outer frame is substantially rectangular.

7. The chair defined in claim 1 wherein said inner frame is substantially U-shaped.

8. The chair defined in claim 1 wherein said outer frame has a back at said upper end, said seat lying between said back and said axis in its first position.

9. The chair defined in claim 1 wherein said seat, said outer frame and said inner frame all define planes including said axis.