GB2158544A

GB2158544A - Demountable framework assembly

Info

Publication number: GB2158544A
Application number: GB08510692A
Authority: GB
Inventors: Robert Mcconnochie
Original assignee: SHEERSPEED U K Ltd
Current assignee: SHEERSPEED U K Ltd
Priority date: 1984-05-11
Filing date: 1985-04-26
Publication date: 1985-11-13
Also published as: GB8510692D0; GB2158544B

Abstract

A demountable framework assembly for use as, for example, a temporary shelter, consists of socket elements (1) each having a plurality of sockets (3) into each of which the tubular ends of respective framework rods (2) can be snap-fitted. Each rod end has a spring-loaded locking catch (5) which engages in a circumferential locking groove (4) in the respective socket and which is releasable by pressing a catch release member (7) on the rod, accessible when the rod is locked in the socket. <IMAGE>

Description

SPECIFICATION Demountable framework assembly This invention relates to a demountable framework assembly.

A known type of framework assembly comprises interconnectible sockets and framework rods which can be releasably interconnected to form frameworks. Such frameworks are useful, for example, as supports for temporary awnings or shelters as used over roadworks, or as supports for tents or horticultural enclosures.

An object of the present invention is to provide an improved framework assembly as aforesaid in which the interconnection of the socket and rods is effected with a positive interlocking, while permitting easy release of the interconnected elements when dissassembling the framework.

According to the present invention there is provided a demountable framework assembly comprising at least one socket element provided with a plurality of sockets in which tubular ends of respective framework rods can be fitted, wherein each socket is formed with an internal circumferential locking groove and each framework rod has a resiliently loading locking catch at its tubular end which fits in the socket, the catch engaging in the locking groove to lock the rod in the socket, and the catch being connected to a catch release member which is accessible when the rod is locked in the socket to disengage the catch from the locking groove.

Positive interlocking of the or each socket element with the framework rods or tubes is ensured by the engagement of the locking catches in the locking grooves of the sockets, while release of the tubes or rods upon disassembly can be effected by the readily accessible catch release members. Such an arrangement is more secure than previously known arrangements relying upon a simple forcefit between framework elements and sockets.

The framework rods may be entirely tubular and may, for example, comprise metal tubes.

Preferably each locking catch is carried by a leaf spring element housed in the end of the associated rod, the associated catch release member being also mounted on the leaf spring element and projecting through a hole in the rod spaced from the locking catch. In a preferred embodiment each leaf spring element comprises a U-shaped spring strip anchored within the end of the rod, with the two limbs of the spring strip extending along the inside surfaces of a tubular end portion of the respective rod, each limb carrying a respective locking catch near its free end projecting through a first hole in said tubular end and, nearer the closed end of the U-shaped spring strip, a respective catch release member projecting through a second hole in said end portion spaced inwardly from the first hole.

With this preferred embodiment the two locking catches carried by the U shaped spring strip engage in a common locking groove in one of the sockets of one of the socket elements and release is effected by squeezing together the two catch release members, which would normally lie in a common diametrical plane of the respective rod.

The or each socket element may be in the form of a tube, sphere or polyhedron having a number of said sockets for receiving respective framework rods. A socket element with rounded external surfaces is found to be ideal for use in constructing frameworks for supporting temporary shelters or tents as used by workmen, since the tent material, usually plastics sheet, can then easily be slid over the socket elements of the assembled framework without snagging.

The or each socket element, which is preferably moulded in plastics material and made in two symmetrical halves secured together, may be designed to provide four equiangularly spaced sockets lying in a common plane. Alternatively, six equiangularly spaced sockets may be formed, the axes of the sockets lying at the centers of the faces of an imaginary cube.

The invention further includes, in another aspect, a framework comprising, in combination: a plurality of socket elements, each having a plurality of sockets, each said socket having an internal circumferential locking groove; a plurality of rods, each having a tubular end which fits releasably in a respective said socket of the socket elements to define a frame; respective locking catches carried at each said tubular rod end, resilient biassing means within said tubular rod ends and acting upon said locking catches, and respective catch release members spaced from the respective locking catches and connected to the respective biassing means, and wherein:: said locking catches are resiliently urged into locking engagement in said locking grooves to lock the rods to the socket elements said catch release members are accessible outside the socket elements when said rods are locked in said sockets.

The invention will be further described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a purely diagrammatic exploded view in perspective of part of a framework assembly according to one embodiment of the invention; Figure 2 is a side elevational view, partly in section, of a socket element and a tubular framework rod forming part of a demountable framework assembly according to another embodiment of the invention; Figure 3 is a perspective view of an enclosure or shelter made from a framework assembly according to the invention; Figure 4 is a plan view, in the direction of arrow IV in Figure 5, of one half of a molded plastics socket element forming part of a framework assembly according to another embodiment of the invention, and Figure 5 is a cross sectional view taken on line V-V in Figure 4.

Referring first to Figure 1, a demountable framework assembly comprises one or more socket elements 1 and a number of tubular framework rods 2. The socket element 1 is in this example in the form of a cube having rounded corners and provided centrally on each of its faces with a socket 3 designed to receive, as a close sliding fit, one end of a said framework rod 2. Each socket 3 is formed with an internal circumferential locking groove 4, in which a resiliently loaded locking catch 5 close to the end of the framework rod 2 can engage to lock the rod 2 in the socket 3.

Each locking catch 5 is carried at a cantilevered end of a leaf spring element 6 anchored within the end of each tubular rod 2, as shown diagrammatically in the cut-away portion of one of the rods 2 in Figure 1. The leaf spring element 6 also carries a catch release member 7 which is spaced from the locking catch 5 on the opposite side of the latter from the free end of the rod 2, by a distance greater than the distance of the locking groove 4 from the mouth of the associated socket 3, so that the catch release member 7 is accessible on the outside of the socket element 1 when the rod 2 is locked in the socket 3.

The spring-loaded locking catch 5 and the catch release member 7 project through respective first and second holes in the side wall of the tubular rod 2, as shown in Figure 1. Alternatively, these two elements may project through a single longitudinal slot made in the side wall of the tubular rod 2.

Figure 2 illustrates an alternative embodiment of the invention, in which each tubular framework rod 2, one only of which is shown, is each provided with two spring locking catches 5 at its ends, the catches 5 being carried at the ends of a U-shaped spring strip 8 located within the end of the rod, with the two limbs of the spring strip 8 extending along the inside surfaces of the rod in a longitudinal direction. Nearer the closed end of the Ushaped strip two respective catch release members 7 are carried by the strip and project through diametrally opposed first holes in the wall of the tubular rod 2.

Although the socket elements 1 shown in Figures 1 and 2 are in the form of cubes with rounded corners, it will be appreciated that in practice these elements may be in the form of a sphere, or a polyhedron with rounded corners.

Frameworks of a variety of configurations and sizes may be assembled using the socket elements 1 and framework rods 2, in simple and rapid operations which do not call for the use of any tools or skilled labor. Each framework rod 2 is introduced into a respective socket 3 after first applying pressure to the catch release member 7 to retract the associated locking catch 5.

To provide for automatic snap-locking of each framework rod 2 in the sockets af the socket element 1 the spring-loaded locking catches 5 may be provided with bevelled or ramp surfaces 5A sloping radially inwardly towards the adjacent free end of the respective rod 2 so that the locking catches 5 are automatically retracted as the rod 2 is pushed into a socket 3, and spring outwards to lock the rod in position when the catch 5 reaches the locking groove 4 within the socket 3.

Once the rod 2 has been fully inserted into the socket 3 the member 7 is released allowing the catch 5 to move outwardly under the action of its loading spring 6 into positive locking engagement with the respective locking groove 4. Disassembly of the framework is easily effected by simply depressing the catch release members 7 to retract the locking catches 5 and then withdrawing the framework tubes 2 from the sockets 3.

An example of a framework formed from a framework assembly according to the invention is illustrated in Figure 3.

The illustrated framework is made up of a number of tubular rods 2 of aluminium interconnected by socket elements 1 as described previously, the framework being in this case a simple free-standing rectangular structure such as may be employed, for example, as a portable shelter for workmen. The upright legs of the framework, formed by four rods 2A, are engaged in respective base members 10 which are molded in the same plastics material as the socket elements 1.Each base member 10 has on its upper face a socket portion 10A provided with five sockets 3 each having an internal locking groove 4 and being in all respects identical to the sockets 3 of the socket elements 1: one of these sockets is vertical and receives lower ends of the upright legs of the frame, while the other four sockets 3 are horizontal and can receive the ends of horizontal bracing struts constituted by further tubular rods 2B.

Two flexible resilient strips 11, each made of plastics material, extend diagonally across the top of the assembled framework and are braced at their opposite ends in respective recesses 12 (Figure 1) formed in the external surface of each socket element 1 between adjacent sockets 3 thereof. The strips 11 are bowed upwardly, forming a support for a cover sheet 13 (shown in broken outline), for example a glass fibre fabric, which fits over the assembled framework. The two strips 11 may be pivotally interconnected at their intersection point.

In the embodiment of Figure 1 release of the locking catches 5 is effected by simply applying thumb pressure to the catch release member 7, which is suitably shaped for this purpose. In the embodiment of Figure 2 and release of the locking catches 5 associated with each tube 2 is effected simply by squeezing the two outwardly projecting catch release members 7 together using a finger and thumb.

The socket elements 1 of the framework assembly are conveniently moulded in plastics material.

For this purpose each socket element 1 may be made in two halves which are subsequently joined together, by means of screws or dowels. Figures 4 and 5 illustrate one half of such a molded socket element, formed with four equiangularly spaced sockets 3 lying in a common plane. The illustrated socket element half has projecting dowels 14 which engage in corrresponding sockets 15 in a complementary half (not shown) of the socket element. The illustrated half of the socket element also has a tubular spigot 15 on which a further socket member (not shown) may be fitted to provide a socket with its axis perpendicular to the plane in which the four illustrated sockets lie, so that when the two socket halves are joined together six equiangularly spaced apart sockets are provided.

In some embodiments of the invention the sockets 3 in the socket element 1 may be inclined at an angle (for example 45 ) to the neighboring sockets of the element; such an arrangement is useful for constructing a framework with a gable roof.

It will be understood that although the framework assemblies described with reference to the drawings employ tubular framework rods, solid rods may equally well be employed provided they are formed with tubular ends or end cavities housing the requisite resiliently loaded locking catches and catch release members.

Claims

1. A demountable framework assembly comprising at least one socket element provided with a plurality of sockets into which the ends of respective framework rods can be fitted, each socket having an internal circumferential locking groove and each framework rod having a tubular end provided with a resiliently loaded locking catch which engages in the locking groove to lock the rod in the socket when the rod is fully inserted therein, and a catch release member connected to the locking catch within the tubular end of the rod, the catch release member being spaced from the catch and being accessible when the rod is locked in the socket for disengaging the catch from the locking groove.

2. A framework assembly according to Claim 1, in which each locking catch is carried by a leaf spring element housed in the tubular end of each framework rod, the associated catch release member being also mounted on the leaf spring element and projecting through a hole in said tubular end of the rod.

3. A framework assembly according to Claim 2, in which the tubular end of each said rod has a first hole and a second hole spaced inwardly from the first hole longitudinally of the rod, and in which each said leaf spring element comprises a U-shaped spring strip located within the tubular end and having two limbs extending along the inside surfaces of said tubular end, one limb being anchored to the tubular end and the other limb carrying the respective locking catch adjacent its free end, projecting through the first hole, and spaced from said free end, the associated catch release member projecting through the second hole.

4. A framework assembly according to any one of Claims 1 to 3, in which the or each socket element is provided with six sockets, the axes of adjacent ones of said sockets being perpendicular to each other.

5. A framework assembly according to any one of Claims 1 to 4, in which the or each socket element is in the form of a sphere, or a cube of polyhedron with rounded corners.

6. A framework assembly according to any one of the preceding claims, in which the or each socket element is moulded in plastics material and comprises two symmetrical halves secured together.

7. A framework assembly according to any one of the preceding claims, in which each framework rod comprises a metal tube.

8. A framework assembly according to Claim 4 or Claim 5, in which the external surface of the or each socket element is formed with recesses between adjacent sockets.

9. A framework assembly according to Claim 8, and further including at least one flexible resilient strip the ends of which are engageable in respective said recesses in respective socket elements in a framework formed from the assembly.

10. A framework assembly according to any one of the preceding claims, including at least one base member the lower face of which is designed to rest upon a supporting surface and the upper face of which is provided with a socket portion having a plurality of sockets with respective internal locking grooves, matching the said sockets of the socket elements.

11. A framework comprising, in combination: a plurality of socket elements, each having a plurality of sockets each formed with an internal circumferential locking grooves; a plurality of rods, each having a tubular end which fits releasably in a respective said socket of the socket elements to define a frame; respective locking catches carried by each said tubular rod end, resilient biassing means within said tubular rod ends and acting upon said locking catches, and respective catch release members spaced from the respective locking catches and connected to the respective biassing means, the locking catches being resiliently urged by the biassing means into locking engagement in said locking grooves to lock the rods to the socket elements, and the catch release members being accessible outside the socket elements when the rods are locked in said sockets.

12. A framework according to Claim 11, and further including at least one flexible resilient strip the ends of which are braced against respective upper socket elements of the frame to hold the strip in an upwardly bowed condition to act as a support, and at least one cover of sheet material which fits over the frame and rests upon the support formed by said strip or strips.

13. A framework according to Claim 11 or Claim 12 and further including base members acting as support feet for the frame, each said base member having on its upper face a socket portion having a plurality of sockets with respective internal locking grooves, matching the said sockets of said socket elements.

14. A demountable framework assembly substantially as herein described with reference to and as shown in the accompanying drawings.