GB2252998A

GB2252998A - Frame corner joint connector

Info

Publication number: GB2252998A
Application number: GB9200538A
Authority: GB
Inventors: Trevor Vella Tomlin
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-01-16
Filing date: 1992-01-10
Publication date: 1992-08-26
Anticipated expiration: 2012-01-10
Also published as: GB9200233D0; GB2252998B; GB9100932D0; GB9200538D0

Abstract

A connecting device, especially for connecting metal extrusions in the assembly of window frames, has two pivotally connected parts each including a core (12) surrounded by an expandable sleeve (20), a wedge (24) and a bolt (18) for driving the wedge into the sleeve for expanding the sleeve to grip the extrusion. The core and sleeve of at least one part of the device are telescoped so that further tightening of the bolt, after expansion of the sleeve, draws the core into the sleeve and pulls the frame extrusions into firm abutment. <IMAGE>

Description

FRAMES This invention relates to frames, and in particular to a frame assembly in which two elongate frames are joined at their ends using a connecting device arranged to extend into hollow sections of the frame members. The invention is concerned especially, but not necessarily exclusively with the manufacture of window frames assembled from metal extrusions.

It is usual for extruded metal window frames to be assembled in the factory and transported as assembled units to the site of the building where they are to be installed. This practice is uneconomic, especially where transportation over large distances is involved and/or the frames must be kept in storage between the time of manufacture and final delivery to the site. During manufacture lengths of extrusion are cut and mitred to enable them to be assembled into a rectangular frame of the required dimensions. At each of the four corners of the frame the two abutting extrusions are joined together by means of an L-shaped cleat arranged with its two legs extending into the respective extrusions.The extrusions are fixed to the cleat by a crimping operation requiring use of a special cleating tool and during which the extrusion is pjrmanently deformed into engagement with serrated surfaces of the cleat. The jointing operation is not one which could easily be performed on site. Apart from the inconvenience of having to transport and store whole window frames, the prior art practice has the disadvantage that frames cannot easily be disassembled, which is sometimes desirable, e.g. for maintenance purposes.

The present invention addresses the problem explained above and accordingly provides a connecting device for securing together the ends of two elongate frame members having hollow sections, the device comprising two interconnected parts for extending into the respective frame members and arranged to be fixed therein, at least one said part comprising a sleeve adapted to be anchored to the frame member, a core surrounded by the sleeve, and means coupled between the core and sleeve for drawing the core into the sleeve thereby to draw into firm abutment the two frame members having the respective parts fixed therein.

In a preferred embodiment each part of the connecting device includes a core, an expandable sleeve surrounding the core, a wedging member engageable in the sleeve, and means for displacing the wedge member relative to the sleeve for expanding the sleeve into tight engagement with the frame member.

In an especially convenient embodiment the displacing means consists of a threaded element, specifically a bolt, which passes through an axial bore in the wedging member, preferably formed as a tapered plug, and which is in screw threaded connection with a tapped hole in the core. Rotation of the bolt, readily achieved by use of an appropriate tool, drives the tapered plug into the sleeve causing the sleeve to expand and grip tightly the hollow section of the frame member, e.g. an extrusion in which it is accommodated. By the same action of tightening the bolt the core, at least on one part of the device, is then pulled into the sleeve for drawing the frame members into firm abutment.To help ensure the sleeve is wedged in position before the core is drawn into it, means may be provided, on either the core or the sleeve to restrain movement of the core into the sleeve until the sleeve has been expanded.

This means may be a resilient abutment element, such as a spring.

It is not essential that the core should be moveable into the sleeve on both parts and on one part stop means, e.g. a shoulder, may be provided on the core or sleeve to limit movement between them.

The sleeve will have an external cross sectional shape to suit that of the section in which it is received, e.g. square, rectangular, hexagonal, etc. and the core and tapered plug will be of complementary shape to the interior cross section of the sleeve, which may conveniently be the same as the external shape. In the particular embodiment described in detail herein, the core and sleeve are cylindrical and the tapered plug is frustoconical, but these configurations are not essential and others may be used without departing from the scope of the invention.

It is preferred that the two parts of the device according to the invention are pivotally connected so that the device may be used to join together frame members at any angle, at least in the range of 900 to 1800, assuming the ends of the frame members are cut off or mitred to meet at the desired angle.

Window frames may be easily assembled at an installation site using coupling devices embodying the invention, even by unskilled workers, whereby it is practical to supply and deliver frames in kit form ready for assembly. The devices can be released by untightening the bolts to facilitate fine adjustment of a corner joint and/or complete dismantling of the frame should it be desired.

The invention also resides in a kit for assembling a frame, comprising two frame members with ends to be connected to each other, and a device for joining said members and including two parts for cooperation with the respective members, each part including means receivable within a substantially closed section of the member and expandable for tight frictional engagement with said section, and tightening means operable to expand said expandable means and to urge the expandable means, and the first said member gripped thereby, towards the end of the second said member engaged by the other part of the joining device.

A better understanding of the invention will be had from the following detailed description of an embodiment, reference being made to the accompanying drawings, in which: Figure 1 is a cross section through one side of a window frame including an outer fixed frame and an inner frame which, in use, receives a double glazing panel and is movable relative to the fixed frame to open and close the window; Figure 2 is a section taken along the line A-A of Figure 1; Figures 3A and 3B are side elevations of the core parts of a frame connecting device; Figures 4A and 4B are axial cross sections through the respective core parts shown in Figs. 3A and 3B; Figures 5A, 5B and 5C are a side elevation, an outer end elevation, and an axial cross section, respectively, of an expandable sleeve of a frame connecting device; and Figures 6A, 6B and 6C show another embodiment of the invention.

Illustrated in Figure 1 is a cross section through part of a window frame which includes an outer stationary frame 1 and an inner frame 2 within which glass sheets are mounted, in use, the inner frame being hinged or otherwise moveably mounted to the outer frame to allow the window to be opened and closed.

Each of the inner and outer frames 1, 2 is assembled from frame members 3 formed as lengths of metal extrusion of appropriate length and mitred at 450 at their ends to enable adjoining members to be connected to form right angle joints at the corners of the frame. One corner segment of each frame 1, 2 is shown in Figure 2. The frame members comprise two main portions 5, 6 separated by a thermal break 4 of conventional form. One main portion 5 includes a substantially cylindrical section 7 which is fully enclosed around the periphery except for an opening defined by a longitudinal slot 8. In the outer frame 1 the slot faces outwardly whereas in the inner frame 2 the slot is directed inwardly. On either side of the slot the extrusion is shaped to define a longitudinal surface with undercut lateral edges extending therealong to enable a locking or cover plate 10 to be fitted by snap engagement over said surface to prevent said cylindrical section 7 being deformed to widen the slot, as described in more detail below.

At the corner of each frame, the two members 3 are connected securely together by means of a joining device having two parts pivoted together.

Each said part has a core 12, the inner end of one core (Figs. 3A and 4A) being bifurcated and the other core (Figs 3B and 4B) having a tongue 14 which is positioned between the forks 15 of the first core, and a pivot pin 16 being inserted through holes provided the forks and tongue so that the cores are pivotally adjustable from an in-line position to and even beyond the 900 position as shown in Fig. 2. The outer end of each core is cylindrical and is provided with a blind tapped hole 17 for receiving a threaded bolt 18.

Surrounding an outer end portion of each core is a sleeve 20 which has a tight but sliding friction fit on the core. The sleeve projects beyond the free end of the core and the projecting sleeve portion is slotted longitudinally, there being four uniformly spaced slots 21 in the embodiment illustrated, to facilitate radial expansion of the sleeve. For effecting such expansion a conical wedge 24 is provided and is connected to the core by the bolt 18 which passes through an axial bore through the wedge.

To facilitate further the action of the wedge the sleeve is provided with an inwardly tapering internal surface 26 at its outer end.

The sleeve is essentially cylindrical but has an integral external key 28 extending along the length thereof and having a width to fit within the slot 8 in the cylindrical section 7 of the extrusion member.

To assemble the frame corner joint, the connection device is taken with its components assembled together but the bolts in an untightened condition so that the sleeves 20 are not expanded by the conical wedges 24. The two parts of the device are inserted into to the extrusion sections 7 of the respective frame members which themselves have been mitred at the ends, e.g. at 450, according to the angle of the joint to be made. A locking cover plate is 10 snapped onto each frame member and extends over at least the length of the section 7 accommodating the sleeve 20.The two bolts 18 are then tightened by engaging an appropriate tool with the bolt heads and turning them so that they become screwed into the cores 12 and hence drive the conical wedges 24 into the sleeves 20 thereby causing the slotted portions of the latter to be expanded radially outwardly into tight engagement with the frame sections 7. It may be mentioned here that the locking cover plates 10 prevent any distortion of the extrusion sections 7 due to the slots 8 therein and the expansion of the sleeves 20. The friction fit between the sleeves 20 and the respective cores 12 prevents them merely sliding forwards over the cores as the wedges are driven inwardly by the action of tightening the bolts.

Eventually each sleeve becomes firmly clamped by compression between the wedge 24 and the extrusion section 7, and the wedge is unable to advance any further along the sleeve. Continued tightening of the bolts 18 then causes the cores 12 to be pulled into the sleeves 20 towards the wedges 24, so that the mitred faces of the frame members are drawn in firm abutment.

The sleeves 20 are prevented from rotating in the sections during tightening of the bolts due to the engagement of the keys 28 in the slots 8. In this way any tendency for the device to become twisted at the pivot pin 16 is avoided.

When the bolts have been correctly tightened a good fitting rigid corner joint is obtained. It will be noted that the connecting devices can be released by undoing the bolts, which may facilitate final adjustments in the joint assembly procedure, as well as allowing subsequent disassembly of the frame should it be desired. Of course, in constructing a rectangular frame four such right angle joints must be completed. However, the connecting device described is not only suitable for right angle joints, the pivotal connection between the two parts enabling it to be used at a wide variety of angles including 1800 or in-line joints. The joints are easy to assemble without demanding special skills or tools, such as cleat crimping tools, so that it is practical for frames to be constructed on site and hence to the transported in unassembled condition.

Modifications to the described device are possible without departing from the invention. It may be advantageous in facilitating assembly if only one part of the connecting device has a core which can be drawn into its sleeve. Thus, on the other part an abutment shoulder, such as indicated by the numeral 30 (Fig. 3A) or 31 (Fig. 5C), may be defined on the core or in the sleeve to limit the movement of the core into the sleeve, in which case expansion of the sleeve by the wedge will not be followed by displacement of the core into the sleeve when the bolt is tightened.

The abutment shoulder may be defined by an integral formation or by a separate element fastened to the core or sleeve.

Also to facilitate frame assembly, in particular correct insertion of the sleeve into the extrusion and to ensure the sleeve is expanded by the wedge before the core is drawn into it upon tightening the bolt, means may be provided to restrain the core against displacement into the sleeve. For example, the core may be equipped with a resilient element, conveniently a bull spring washer 33 (Fig. 3A) located in a peripheral groove, against which the sleeve will initially abut until the tension applied by the bolt is sufficient to overcome the spring and cause the core to be drawn into the sleeve to tighten the frame joint. Of course, an equivalent spring member could instead be provided in the sleeve bore.

Another embodiment of a connecting device according to the invention is illustrated in Figures 6A, 6B and 6C. This device is of basically the same construction as that described above but differs in respect of the features described below. The sleeves 120 are shaped as rectangular blocks for cooperation with corresponding hollow sections in the frame members (not shown) to be connected together. The outer ends of the blocks are slotted, e.g. as shown in either Fig. 6B or Fig. 6C, to provide segments which can be forced apart by the wedge 124 to expand the block to grip the frame member. The wedges are coupled to the respective pistons or cores 112 by Allen screws 118. The cores are each provided with a rearwardly facing shoulder 130 and at least one core is fitted with a spring collar, e.g. a coil spring or a nylon ring 133 as shown, between this shoulder 130 and the forward end face 135 of the corresponding block 120. When the Allen screw is tightened, sliding movement of the block 120 over the core 112 is limited by the spring ring 133 abutting between the confronting faces, until the block has been expanded by the wedge 124 to grip tightly the frame member, after which continued tightening of the screw draws the core 112 into the block, the spring ring 133 compressing, e.g. deforming by buckling, to allow this movement of the core into the block. In this way the joint between the frame members is tightened as described above.

While it is preferred to employ expandable sleeves and wedges for fixing the sleeves in the frame members, this is not essential and the sleeves could instead be anchored within the frame member by drilling a hole through the frame member and into the sleeve and inserting a screw to fix the sleeve in position.

Although specifically described with reference to frames assembled from metal extrusions, it is to be noted that the invention is also applicable to frame members of timber (wood), plastics or any other material. Furthermore, the frame members can have box sections or slotted sections for accommodating the connecting device.

Claims

CLAIMS:

1. A connecting device for securing together the ends of two elongate frame members having hollow sections, the device comprising two interconnected parts for extending into the respective frame members and arranged to be fixed therein, at least one said part comprising a sleeve adapted to be anchored to the frame member, a core surrounded by the sleeve, and means coupled between the core and sleeve for drawing the core into the sleeve thereby to draw into firm abutment the two frame members having the respective parts fixed therein.

2. A connecting device according to claim 1, wherein each part has a core, an expandable sleeve, a wedging member engagable in the sleeve and means for displacing the wedging member relative to the sleeve for expanding the sleeve into tight engagement with the frame member.

3. A connecting device according to claim 2, wherein the wedging member of said at least one part is coupled to the core by said drawing means, whereby operation of said drawing means first displaces the wedge member to expand the sleeve and then draws the core into the sleeve.

4. A connecting device according to claim 3, wherein means are provided for restraining movement of the core into the sleeve until the sleeve has been expanded by the wedging member.

5. A connecting device according to claim 4, wherein said restraining means comprises a resilient abutment element.

6. A connecting device according to any one of claims 2 to 5, wherein on one part of the device stop means are provided to limit movement between the sleeve and the core whereby expansion of the sleeve member is not followed by relative movement of the core and sleeve.

7. A connecting device according to any one of claims 2 to 6, wherein the means for displacing the wedging member comprises a screw threaded element connected to the core.

8. A connecting device according to claim 7, wherein the threaded element passes through a bore in the wedging member.

9. A connecting device according to any one of the preceding claims wherein the two parts are pivotally interconnected.

10. A connecting device according to claim 9, wherein the two parts are pivotally adjustable between 900 and 1800, at least.

11. A connecting device substantially as herein described with reference to the accompanying drawings

12. A frame assembly comprising two elongate frame members of hollow section connected end-to-end by a connecting device as defined in any one of the preceding claims.

13. A kit for assembling a frame, comprising two frame members of hollow section and with ends to be connected to each other, and a connecting device for joining said frame members and including two parts for secure cooperation with the respective frame members, at least one said part including means receivable within a substantially closed section of the frame member and expandable for tight frictional engagement with said section, and tightening means operable to expand said expandable means and to urge the expandable means, and the said frame member gripped thereby, toward the end of the other frame member in which the other part of the connecting device is fixed.

14. A kit according to claim 13, wherein the connecting device is as claimed in any one of claims 1 to 11.