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(11) | EP 0 256 837 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Foldable frame assembly |
| (57) The present invention provides a foldable frame assembly, comprising a pair of complementary
X-shaped side frames each having two bar members (1, 2, 1ʹ, 2ʹ) hinged together intermediate
their ends to permit folding and unfolding in the plane of the X, the two side frames
being mutually parallel and in register with each other; and a pair of centrally hinged
transverse X-frame support stays, each having two substantially straight stay members
(4, 5, 4ʹ, 5ʹ) hinged together at their mid points (6, 6ʹ) to permit folding and unfolding
in the plane of the X which is perpendicular to the plane of the side frames. An end
of each stay member is hinged to an end of a side frame bar member so as to permit
pivoting both in the plane of the stay members and in the plane of the respective
bar members, whereby folding and unfolding of the side frames causes simultaneous
and corresponding folding and unfolding of the support stays. The foldable frame can
form the basis for a foldable seat or a foldable chair. |
[0001] This invention relates to a foldable frame assembly, and more particularly to a foldable seat and foldable chair incorporating such assembly.
[0002] There are various kinds of foldable chair presently available, probably the most common being that known as the deckchair. Such chairs fold essentially in one plane only, so that when folded they form a flat package. An object of the present invention is to provide a chair which is foldable in two directions simultaneously, so that it can be reduced to a minimum size for storage and carrying.
[0003] The present invention accordingly provides a foldable frame assembly, comprising a pair of complementary X-shaped side frames each having two bar members hinged together intermediate their ends to permit folding and unfolding in the plane of the X, the two side frames being mutually parallel and in register with each other; and a pair of centrally hinged transverse X-frame support stays, each having two substantially straight stay members hinged together at their mid points to permit folding and unfolding in the plane of the X which is perpendicular to the plane of the side frames, an end of each stay member being hinged to an end of a side frame bar member so as to permit pivoting both in the plane of the stay members and in the plane of the respective bar members, whereby folding and unfolding of the side frames causes simultaneous and corresponding folding and unfolding of the support stays.
[0004] The foldable frame defined above can be adapted to form the basis for a foldable seat or a foldable chair by incorporating detachable cross-members with a flexible seat material supported between them.
[0005] Thus, in one embodiment, the invention provides a foldable seat, comprising a foldable frame as defined above, a pair of cross-members detachably supportable each between a respective pair of upper ends of the side frame bar members, and a flexible seat material supported by and extendible between said cross-members.
[0006] In another embodiment, the invention provides a foldable chair, comprising a foldable frame as defined above, a pair of upper extension members respectively hinged to an upper end of a side frame bar member and to the upper end of the complementary side frame bar member, said upper extension members being pivotable in the respective planes of the side frames; a pair of brace members hinged at their lower ends to the respective lower ends of the side frame bar members below the hinge points of the upper extension members, and at their upper ends respectively to the upper extension members intermediate the ends of the latter; latch means for detachable locking of at least one of the side frames in an unfolded position; a first cross-member detachably supportable between the upper ends of the upper extension members; a second cross-member detachably supportable between the free upper ends of the side frame bar members; and a flexible seat material supported by and extendible between the first and second cross-members.
[0007] Reference is now made to the accompanying drawings, in which:
Figure 1 is a perspective view from the side and above of a foldable frame assembly for a chair according to a preferred embodiment of the invention;
Figure 2 is a view on a larger scale of an embodiment of two-way hinge for use in the invention;
Figure 3 is a perspective view from the front, side and above of a foldable chair incorporating the foldable frame assembly of Figure 1;
Figure 4 is a perspective view from the rear and side of the same chair;
Figure 5 is a perspective view from the side and above of the frame assembly of Figure 1 in between the completely folded and the completely unfolded position; and
Figure 6 is a view of the completely folded chair.&
[0008] The foldable chair incorporates a foldable frame assembly comprising two X-shaped side frames hingedly interconnected with two sets of transverse X-frame support stays.
[0009] Referring more particularly to Figure 1, the first side frame has two rigid bar members 1 and 2 which are hinged together at a point 3 halfway along to form a X-shape. Hinging about the point 3 permits the bar members 1 and 2 to be folded and unfolded in the plane of the X. The second side frame is parallel and in register with the first, and comprises corresponding components 1ʹ, 2ʹ and 3ʹ.
[0010] A pair of centrally hinged transverse X-frame support stays are provided. The first of these links the upper ends of the bar members 1 and 1ʹ respectively with the lower ends of the bar members 2 and 2ʹ. More particularly, this stay assembly comprises a substantially straight stay member 4 linking the upper end of the bar member 1 to the lower end of the bar member 2ʹ, and a substantially straight stay member 5 linking the lower end of the bar member 2 to the upper end of the bar member 1ʹ. The stay members 4 and 5 are hinged together at their midpoints 6 to form an X shape and to permit folding and unfolding of the stay members in the plane of this X, which is perpendicular to the plane of the side frames. Each end of the stay members 4 and 5 is hinged by a two-way hinge (see Figure 2) to the end of the respective side frame bar member so as to permit pivoting at such hinge point both in the plane of the stay members and in the plane of the respective bar members. A complementary second set of stay members is provided to link points close to the end of the top of the bar member 2ʹ to the proximity of the lower end of the bar member 1, and similarly from near the top of the bar member 2 to the proximity of the lower end of the bar member 1ʹ. This second set of stay members is designated by the numerals 4ʹ, 5ʹ and 6ʹ, and are hinged to each other and to the respective ends of the side frame bar members in a similar way to the stay members 4 and 5.
[0011] An example of the two-way hinge is shown in Figure 2, the side frame bar member 2ʹ being of tubular metal in this case. The hinge is formed by a right-angled plate metal bracket 20. One limb of the bracket is hinged by a rivet 21 to the member 2ʹ to permit turning according to arrow A. The other limb of the bracket is hinged by a rivet 22 to the member 5ʹ to permit turning according to arrow B. The turning planes of arrows A and B are at right angles to each other.
[0012] The mutual hinging described above of the side frame bar members and the stay members has the result that the folding and unfolding of the side frames causes simultaneous and corresponding folding and unfolding of the support stays. Thus, if the frame assembly starts in the completely folded position, then gradual unfolding of the side frames will cause gradual unfolding of the support stays to a corresponding extent, so the frame assembly will open both lengthwise and widthwise simultaneously. Similarly, when the open assembly is gradually folded, both the side frames and the support stays will fold up simultaneously to a corresponding extent.
[0013] In one embodiment of the invention, the foldable frame assembly thus far described can be adapted to form the basis for a foldable seat. A first cross-member is detachably supported between the upper ends of the side frame bar members 1 and 1ʹ, and a second cross-member is detachably supported between the upper ends. of the side frame bar members 2 and 2ʹ. A flexible seat material can then be supported by and extended between the two cross-members. When the seat is to be folded up, the two cross-members are detached from the frame assembly and are rolled up together with the flexible seat material. The frame assembly itself can then be folded up as described above. The folded seat thus comprises two folded components whi together form a compact package.
[0014] In a preferred embodiment of the invention, as actually illustrated in the drawings, the basic frame assembly already described is extended by further members to form a foldable chair having characteristics somewhat similar to a deckchair, except for a substantially increased extent of folding. A pair of upper extension members 7 and 7ʹ is hinged at the lower ends respectively to the upper ends of the side frame bar members 2 and 2ʹ. The upper extension members are thus pivotable in the planes of the respective side frames. Two brace members 8 and 8ʹ are hinged at their lower ends to the respective lower ends of the side frame bar members 1 and 1ʹ approximately beneath the hinge points of the upper extension members 7 and 7ʹ respectively. The brace members 8 and 8ʹ are hinged at their upper ends respectively to the upper extension members 7 and 7ʹ intermediate the ends of the latter. Two adjustable latches 9 and 9ʹ are respectively hinged intermediate the ends of the brace members 8 and 8ʹ, and can engage respectively with latching points 10 and 10ʹ where the respective upper extension member is hinged to the respective side frame bar member. When the latching means are in engagement, both of the side frames are locked in an unfolded position as shown in Figure 1. The upper extension members and brace members are also correspondingly locked. A plurality of latching points is provided on the latches 9 and 9ʹ so that the chair can be locked in a variety of positions with the upper extension members at various angles.
[0015] Assembly of the chair is completed by detachably supporting a first cross-member 11 between the upper ends of the upper extension members 7 and 7ʹ. Slots 12 and 12ʹ are provided at the upper ends of the upper extension members, and the first cross-member 11 is dimensioned so as to fit into these slots. A second cross-member 13 can fit into corresponding slots 14 and 14ʹ at the free upper ends of the side frame bar members 1 and 1ʹ. A flexible seat material 15 is supported by and extendible between the first and second cross-members 11 and 13.
[0016] In order to fold up the chair, the cross-members 11 and 13 are first detached from the corresponding slots, and the seat material can then be rolled up around the two cross-members to form a compact package as shown on the left in Figure 6. This leaves the chair frame as shown in Figure 1. The latches 9 and 9ʹ are first disengaged from the latch points 10 and 10ʹ, and the upper ends of the extension members 7 and 7ʹ are pulled back in the directions shown by the arrows. This causes the chair frame to gradually fold up, the side frames folding simultaneously with the support stay assemblies. An intermediate position is shown in Figure 5, and it will be noted that the lower angle formed between each upper extension member and the corresponding side train bar member linked thereto has changed from a reflex angle (as in Figure 1) to an acute angle (as in Figure 5). Folding of the chair frame is then completed until it is complete, and the folded frame forms a compact package as shown on the righthand side in Figure 6.
[0017] Erection of the chair from the folded position is the reverse of the folding procedure described above. The frame assembly is first unfolded and then locked in the unfolded position by the latch means. The seat material is then unrolled and the cross-members are inserted into the corresponding slots, with the seat material extending between them.
[0018] Any rigid material having sufficient strength is suitable for construction of the frame assembly. In one embodiment, the side frame members and upper extension members are made of wood, whilst the support stay assemblies, the brace members and the latches are made of plate material. Alternative materials such as metal tubing, e.g. aluminium, and plastics materials are of course possible. In the case of metal tubing, the cross-members 11 and 13 right-angle turns at their ends for fitting into the upper ends of the upper extension members 7 and 7ʹ and the side frame bar members 1 and 1ʹ, respectively, which do not in this case have the slots 12, 12ʹ, 14 and 14ʹ. The seat material can be made of canvas, but synthetic materials or any kind of flexible construction are also possible.
1. A foldable frame assembly, comprising a pair of complementary X-shaped side frames
each having two bar members hinged together intermediate their ends to permit folding
and unfolding in the plane of the X, the two side frames being mutually parallel and
in register with each other; and a pair of centrally hinged transverse X-frame support
stays, each having two substantially straight stay members hinged together at their
mid points to permit folding and unfolding in the plane of the X which is perpendicular
to the plane of the side frames, an end of each stay member being hinged to an end
of a side frame bar member so as to permit pivoting both in the plane of the stay
members and in the plane of the respective bar members, whereby folding and unfolding
of the side frames causes simultaneous and corresponding folding and unfolding of
the support stays.
2. A foldable seat, comprising a foldable frame as claimed in claim 1, a pair of cross-members
detachably supportable each between a respective pair of upper ends of the side frame
bar members, and a flexible seat material supported by and extendible between said
cross-members.
3. A foldable chair, comprising a foldable frame as claimed in claim 1, a pair of
upper extension members respectively hinged to an upper end of a side frame bar member
and to the upper end of the complementary side frame bar member, said upper extension
members being pivotable in the respective planes of the side frames; a pair of brace
members hinged at their lower ends to the respective lower ends of the side frame
bar members below the hinge points of the upper extension members, and at their upper
ends respectively to the upper extension members intermediate the ends of the latter;
latch means for detachable locking of at least one of the side frames in an unfolded
position; a first cross-member detachably supportable between the upper ends of the
upper extension members; a second cross-member detachably supportable between the
free upper ends of the side frame bar members; and a flexible seat material supported
by and extendible between the first and second cross-members.