WO2003067001A1

WO2003067001A1 - A frame clamp

Info

Publication number: WO2003067001A1
Application number: PCT/GB2003/000526
Authority: WO
Inventors: Michael Gardner
Original assignee: Qef Products Limited
Priority date: 2002-02-08
Filing date: 2003-02-08
Publication date: 2003-08-14
Also published as: GB0202960D0; AU2003244408A1; GB2401126A; GB0417385D0

Abstract

A frame clamp is adapted to connect members of a framework. The clamp includes a hub having an axis and at least one ring attached to the hub. A plurality of elongate frame members each of which has a proximal end thereof is pivotally mounted on the ring. A locking member is mounted in the hub and movable relative thereto between locking and release positions. The locking member when in the locking position engages each frame member to lock it in an erected configuration, in which the frame members extend angularly disposed with respect to the hub axis. When the locking ring is moved to the release position, it disengages each frame member, whereby the frame members are movable to a collapsed configuration, in which they lie substantially parallel with the hub axis.

Description

A Frame Clamp

This invention relates to a frame clamp for the joining together the members of a framework.

Frameworks comprising a plurality of tubes or rods joined together by clamps are variously used as scaffolding on construction sites and as support structures for tents and shelters for a variety of purposes, e.g. cold frames, cloches, fishermen's or birdwatchers' shelters, workmen's shelters, crime scene shelters, mosquito nets, military and emergency shelters.

In most cases, an important factor to be considered in assessing the suitability of a framework and the associated clamp arrangements in a particular context is that of the ease and speed with which the framework can be erected and collapsed, particularly in adverse conditions. Another very important factor is the weight of the framework and clamps, particularly as many of the applications relate to products that have to be carried by the user to the location of use.

Many such clamp arrangements have been proposed, with varying degrees of success in meeting the desired criteria of erection/collapsing performance. In US 4192334 there is described a collapsible dome shaped framework for a tent or the like comprising a ring formed of alternate fixed and pivoting sections, to each pivoting section of which is attached a frame member. In the collapsed configuration the frame members extend at right angles to the plane of the ring. To erect the framework, each frame member is in turn pivoted into the plane of the ring and locked in position. To collapse the framework each frame member is in turn unlocked and pivoted into the collapsed configuration.

These operations are relatively time consuming, and the framework can be difficult to handle when some of the frame members are in the erected configuration and some of them are in the collapsed configuration.

In accordance with the present invention, there is provided a frame clamp adapted to connect members of a framework, comprising a hub having an axis, at least one ring attached to the hub, a plurality of elongate frame members each of which has a proximal end thereof pivotally mounted on the ring, a locking member mounted in the hub and movable relative thereto between locking and release positions, whereby the locking member when in the locking position engages each frame member to lock it in an erected configuration in which the frame members extend angularly disposed with respect to the hub axis, and when moved to the release position disengages each frame member whereby the frame members are movable to a collapsed configuration In which they lie substantially parallel with the hub axis.

The locking member, when in the locking position, may engage the proximal end of each frame member. The locking member may comprise a disc mounted on a spindle, and the disc may have a cylindrical outer surface adapted to engage the proximal end of each frame member. The cylindrical surface and the spindle may have a common axis along the hub axis. The locking member may be axially movable relative to the hub between the locking and release positions, and may be resiliency biased towards the locking position. In this case the outer surface of the locking member may have a tapered cylindrical portion. Alternatively, the locking member may be mounted in the hub to rotate about the axis thereof. In this case the cylindrical surface may have a plurality of recesses therein, whereby each recess may be aligned with a respective frame member to disengage the cylindrical surface from the proximal end of that frame member.

The frame clamp may comprise a second ring attached to the hub, concentric with and axially spaced from the one ring, and the second ring may be of greater diameter than the one ring. The second ring may be disposed to that side of the one ring remote from the locking member. The second ring may be disposed relative to the one ring whereby the frame members abut the second ring when they are locked in the erected configuration.

The frame clamp may also comprise a locking device operable to lock the locking member in the locking position. The locking device may comprise a pin slidably mounted in the hub and operable to engage a recess in the spindle of the locking member. The pin may be resiliently biased towards the spindle.

An example of a frame clamp in accordance with the invention will now be described with reference to the accompanying drawings, in which:

Fig. 1 is a plan view of a first example of a frame clamp in a locked erected configuration;

Fig. 2 is a front view of the clamp of Fig. 1 in the locked erected configuration; Fig. 3 is a plan view of the clamp of Fig. 1 in a collapsed configuration;

Fig. 4 is a front view of the clamp of Fig. 1 in the collapsed configuration;

Fig. 5 is a side view of part of the clamp in the direction of arrow V in Fig. 1 ;

Fig. 6 is a side view of part of the clamp in the direction of arrow VI in Fig. 3;

Fig. 7 is a plan view of part of a second example of a frame clamp in a locked erected configuration; and

Fig. 8 is a plan view of part of the frame clamp of Fig. 7 in a collapsed configuration.

Figs. 1 , 2 and 5 show a frame clamp 10 in a locked erected configuration. The clamp 10 comprises a hub 11 having a central axis 12. Mounted in the hub concentrically about and spaced along the axis 12 are two rings 13, 14. Ring 14 is of greater diameter than ring 13. A plurality of elongate frame members 15 are mounted on the frame clamp 10, four being shown but there may be more or fewer than four depending on the application. The ring 13 passes through a hole at a proximal end 16 of each frame member 15 whereby the frame member is pivotally mounted on the ring 13. Mounted in the hub 11 is a locking member 17.

The locking member 17 comprises a disc 18 and a spindle 19. The spindle 19 is retained in the hub 11 so as to be slidable along the axis 12. A spring 20 biases the locking member 17 towards the locking position shown in Figs. 1 and 2. A locking pin 21 engages a recess 22 in the spindle 19 to retain the locking member 17 in the locking position. The locking pin 21 is biased by a spring 23 towards this retaining position. In this locked erected configuration, the proximal end 16 of each frame member 15 abuts the cylindrical outer surface 24 of the disc 18 of the locking member 17. The contact between the proximal ends 16 and the surface 24 maintains the frame members 15 in the erected configuration in which the frame members 15 also contact the larger ring 14. By these means the frame members 15 are locked into the erected configuration and cannot rotate into the collapsed configuration or beyond the erected configuration.

By withdrawing the locking pin 21 from the recess 22, the locking member 17 is able to be pushed against the force of the spring 20 to its release position as shown in Figs. 3, 4 and 6. This movement takes the surface 24 out of contact with the proximal ends 16 of the frame members 15. The frame members 15 are then free to pivot about the ring 13 to the collapsed configuration shown in Figs 3, 4 and 6. This freedom of movement is facilitated by the disc 18 having a tapered cylindrical portion 25. The spring 20 then returns the locking member 17 to the original position.

In Figs. 1 , 2 and 5 the frame members 15 are shown lying in a common plane perpendicular to the axis 12. However, for certain applications it may be desired to have the frame members lying at an angle to the axis 12, i.e. on the surface of an imaginary cone. This may be effected by suitable axial spacing of the rings 13, 14 relative to the diameter of the frame members 15, whereby the frame members 15 contact the ring 14 before reaching the plane perpendicular to the axis 12. Another example of a frame clamp 70 is shown in Figs. 7 and 8. Parts corresponding with those shown in Figs. 1 to 6 are identified by the same reference numerals.

In this example, the locking member 71 is mounted in the hub 11 so as to be rotatable about the axis 12. The locking member 71 has a number of recesses 72 corresponding with the number of frame members 15, at corresponding relative angular dispositions when seen in plan view. When in the locked erected disposition shown in Fig. 7, the proximal ends 16 of the frame members 15 are in contact with the cylindrical surface 24 of the locking member 71 , and the locking member 71 is locked in this position by means of the locking pin 21.

By withdrawing the locking pin 21 , the locking member 71 can be rotated about axis 12 to the position shown in Fig. 8. In this position the recesses 72 align with the frame members 15, which are then free to rotate about the small ring 13 to the collapsed configuration.

By means of the invention a frame clamp is provided that enables the frame to be erected or collapsed with a single movement of the frame clamp. Difficult handling of the frame whilst some frame members are in the erected configuration and some are in the collapsed configuration is avoided. The frame is securely locked when in the erected configuration, thereby minimising the risk of inadvertent or unexpected collapse.

Claims

1. A frame clamp adapted to connect members of a framework, comprising a hub having an axis, at least one ring attached to the hub, a plurality of elongate frame members each of which has a proximal end thereof pivotally mounted on the ring, a locking member mounted in the hub and movable relative thereto between locking and release positions, whereby the locking member when in the locking position engages each frame member to lock it in an erected configuration in which the frame members extend angularly disposed with respect to the hub axis, and when moved to the release position disengages each frame member whereby the frame members are movable to a collapsed configuration in which they lie substantially parallel with the hub axis.

2. A frame clamp according to claim 1 , wherein the locking member, when in the locking position, engages the proximal end of each frame member.

3. A frame clamp according to claim 2, wherein the locking member comprises a disc mounted on a spindle.

4. A frame clamp according to claim 3, wherein the disc has a cylindrical outer surface adapted to engage the proximal end of each frame member.

5. A frame clamp according to claim 4, wherein the cylindrical surface and the spindle have a common axis along the hub axis.

6. A frame clamp according to claim 5, wherein the locking member is axially movable relative to the hub between the locking and release positions.

7. A frame clamp according to claim 6, wherein the locking member is resiliently biased towards the locking position.

8. A frame clamp according to claim 7, wherein the outer surface of the locking member has a tapered cylindrical portion.

9. A frame clamp according to claim 5, wherein the locking member is mounted in the hub to rotate about the axis thereof.

10. A frame clamp according to claim 9, wherein the cylindrical surface has a plurality of recesses therein.

11. A frame clamp according to claim 10, wherein each recess may be aligned with a respective frame member to disengage the cylindrical surface from the proximal end of that frame member.

12. A frame clamp according to any of claims 1 to 11 , further comprising a second ring attached to the hub.

13. A frame damp according to claim 12, wherein the second ring is concentric with and axially spaced from the one ring.

14. A frame damp according to claim 13, wherein the second ring is of greater diameter than the one ring.

15. A frame damp according to claim 14, wherein the second ring is disposed to that side of the one ring remote from the locking member .

16. A frame clamp according to claim 1 , wherein the second ring is disposed relative to the one ring whereby the frame members abut the second ring when they are locked in the erected configuration.

17. A frame clamp according to any of claims 1 to 16, further comprising a locking device operable to lock the locking member in the locking position.

18. A frame clamp according to claim 17, wherein the locking member has a spindle and the locking device comprises a pin slidably mounted in the hub and operable to engage a recess in the spindle of the locking member.

19. A frame clamp according to claim 18, wherein the pin is resiliently biased towards the spindle.