GB2245676A

GB2245676A - Forming a joint

Info

Publication number: GB2245676A
Application number: GB9014217A
Authority: GB
Inventors: Jack Lane
Original assignee: EDGEFOLD WOOD PRODUCTS Ltd
Current assignee: EDGEFOLD WOOD PRODUCTS Ltd
Priority date: 1990-06-26
Filing date: 1990-06-26
Publication date: 1992-01-08
Anticipated expiration: 2010-06-26
Also published as: GB9014217D0; GB2245676B

Abstract

Right angled corner joints are made by holding a pair of mitred and pre-slotted members (30, 2) against guiderails or fences (10, 11) on a bench (12) and a connector (40) is forced into preformed slots (33, 4) adjacent the mitred ends. In accordance with the invention, the members (2, 30), and their respective fences (11, 10) are set an angle alpha which instead of being 90 DEG is 90.5 DEG to 92 DEG . By setting the fences not at a right angle joints are obtained of consistent acceptability and lacking any tendency for the outside edge of the joint to open. <IMAGE>

Description

METHOD OF FORMING A JOINT, JOINT THEREBY FORMED AND APPARATUS FOR USE THEREIN This inention relates to a method of forming a joint, a joint formed by that method and apparatus for use in the method.

In the building industry, the provision of accurate right angle joints, particularly in window frames but also in other applications is important. Conventionally such joints have been made by the mortise and tenon method.

However to obtain a satisfactory joint in this way requires a considerable amount of skill and time.

Various methods have been proposed for de-skilling and speedirg up frame manufacture. Such methods are for example described in B-A-2102908r GB-A-2076924, GB-A-2076103 and GB-A-2013301.

A more recent proposal has been described in GB-A-2167513.

According to the method described in this patent specification, joints are made using a connector comprising a weEb and gripping formations on the web, the gripping formations generally being in the form of mutually divergent flanges at opposite margins of the web.

The members to be joined, e.g. window frame members, are each provided, at the surfaces to be joined with one or more slots such that, when the two members are brought together with the adjacent faces abutting, the slot positions correspond to form at least one single common slot across the joint. Then, with the members to be joined abutting, a connector is forced into the or each commcn slot such that the gripping formations engage with the frame members under pressure, the pressure being sufficient to deform the members and the engagement being such as to urge the members together at the interface according to the patent specification.

While GB-A-2167519 offers a potentially quick method of forming a firm joint with a relatively small amount of swill 1117 it has been found that the joints formed are not of consistently acceptable quality. In particular it has been found that right angled joints, which are of course the most commonly used joints, formed in this way by introduction of the web from the inside of the joint angle tend to separate at the outside edge of the joint. This results in a joint which is inaccurate, unattractive, and also has a route for the easy entrance of water into the joint.

It has now surprisingly been found that if, rather than being set at right angles for insertion of the web, the members to be joined are set at slightly greater than 900 for the insertion of the web joints of consistently high quality may be obtained.

According to the present invention there is provided a method of forming a right angled joint between two members wherein the ends to be joined are mitred, and wherein each member to be joined is provided, at the face to be joined, with a slot defined between flat, mutually parallel surfaces and having an open side at the surface to be joined and an open end at the adjacent inside face of the member such that, when the members are placed with the two feces together, the slots are mutually aligned to form a single slot which is common to the members and witch has mutually parallel boundary surfaces defining opposite boundaries of the common slot, which method comprises positioning the members to be joined with the surfaces to be joined facing each other and substantially abutting to the outside of the join to be made, the members being set at 90.50 to 920 to each other, and forcing, from the inside of the joint to be made and along the pair of corresponding slots in the members and between the members, a connector having a web and gripping formations on the web with at least one of the gripping formations In engagement under pressure with one of the members and at least another of the gripping members in engagement under pressure with the other of the members, the pressure being sufficient to deform the members and the engagement being such as to bring the members together at the interface.

With the method of the present invention, it is found that with the forcing in of the connector web, the frame members are brought together at the interface to make consistently acceptable joints and without the outside edge of the joint being opened as was obtained previously with the frames being set at a right angle for joining.

The results ars particularly good for the obtaining of a frame comprising four right angled joints obtained by the present invention to obtain a frame which is firm and accurately joined.

Moreover the present invention provides a rapid method of forming a joint which can be obtained with accuracy and consistency with little prior experience. The joints furmed by the present invention are firm and this enables the assembly to be handled without having to wait for any adhesive which has been applied to become cured. There is, therefore, a saving in assembly time as compared with prior jointing methods.

The invention also provides a joint produced by the method according to the present invention.

The method of the present invention is particularly suited for the manufacture of window frames.

The members to be joined by the present method are generally of wood but any suitable material can be used.

Members having the desired profile, e.g. fo the frame to be made, are prepared for joints by beIng cut to length and provided with a 450 mitred end. Then the faces to be joined are provided with corresponding slots, e.g. cut with a circular saw.

The connector web used according to the present invention is typically made of metal but can be made of any suitable material having the required strength. The connector is generally a flat member having extending from the surface of it at least one pair of flanges which diverge towards the leading edge of the connector.

The present invention further provides apparatus for use in the provision of a right angled joint, which apparatus comprises a pair of guide rails or fences set at 90.50 to 920 with respect to each other, and on the intersection of the angle formed between the guide rails or fences, means for holding a connector web for use according to the present invention and for advancing the connector web towards the angle and drive the connector web into members to be joined.

The member for holding the connector web may for example be in the form of a cassette which is advanced pneumatically or hydraulically to drive the connector web into the slot in the frame member. The connector web carrier can be adaptable to vary the number, size and position of connector webs to be used depending upon the requirement of the joint to be made. Similarly the pneumatic or hyraulic pressure used may be varied.

The guide fences or rails are preferably at an angle of 0 910.

The members to be joined are positioned adjacent these fences or rails and then move away with the insertion of the connecting member and formation of the 900 angle joint.

The invention is further illustrated with reference to the accompanying drawings wherein: Figure 1 shows the prepared end of a window frame member to be coined by the present invention.

Figure 2 is a plan view of the members to be joined and apparatus of the present invention in position prior to the insertion of the connector web.

Figure 3 is a plan view of the joint formed following the insertion of the connector web iD Figure 2.

Figure 4 is a section aLong the line of IV-IV in Figure 3.

Referring to Figure 1 of the drawings, there is shown the mitred end 1 of a window frame member 2 having a profile such as to provide a window rebate at 3. At the mitred end 1, the window frame member 2 has been provided with two parallel slots 4 and 5, cut with a circular saw and extending into the inside face 6 of the window frame member.

Turning now to Figure 2 there is shown apparatus comprising a pair of guide fences 10 and 11 which extend vertically from a bench 12 and are secured to the bench 12 such that the angle alpha between the two guide fences 10 0 and 11 is 91 On the line intersecting the angle alpha there is provided a holder 20 for the connector web to be inserted, in this case for two connector webs, one directly below the other.

The holder 20 is capable of being driven forward towards the angle alpha between guide fences 10 and li as shown bv the arrow on the drawing. This may be achieved for example by hydraulic or pneumatic means (not shown).

To form a joint according to the present invention the frame member 2 of Figure 1 is placed with its outside face 7 against guide fence 11.

A corresponding window frame member 30 is placed with its outside face 31 against guide fence 10. Corresponding window frame member 30 also has a mitred end j2 comprising saw blade cut parallel slots (only 33 shown), corresponding to the parallel slots 4 and 5 in indo frame member 2. The window frame member 30 has the same profile as that of window frame member 2 and includes a rebate at 34 in the same way.

In position against the guide fences 10 and 11, the mitred ends 1 and 32 of the window frame member 2 and 30 face each other with the slots 4, 5 and 33 (and other not shown) corresponding to each other and the same height.

The window frame members 20 and 30 abut at the outer edge of their mitred ends adjacent the guide fences. However because the angle alpha is greater than 9007 at the inside edges of the mitred ends, the frame members 2 an 30 diverge.

Suitably, the window frame members 2 and 30 are held in position against the guide fences 10 and 11 and down against the bench 12 by means of two pneumatically or hydraulically operated pistons urging the frame members towards the bench 12. However of course care has to be taken that the force exerted by these pistons is not so great as to prevent the frame members moving away from the guide fences during formation of the joint.

The connector web holder 20 has mounted on it two connector webs (only one show) directly beneath one another and at a height corresponding to the height of the slots 4, 5, 33 in frame members 2 and 30.

Each connector 40 comprises a flat web 41 which is of substantially the same thickness as the height of the slots 4, 5, 33 in frame members 2 and 30. Extending from the flat web 41 are a pair of ribs 42 and 43. The ribs 42 and 43 diverge from each other towards the leading edge 44 of the connector 40. The underside of connector 40 and flat web 41 is provided with a similar pair of mutually diverging extending ribs.

To form a joint, the Connectors 40 on holder 20 are driven forward in the direction of the arrow shown in Figure 2.

The right hand part of upper connector 40 as shown in Figure 2 enters slot 4 in frame member 2 and the left hand edge enters slot 33 in frame member 30. SimIlarly the right hand side of the lower connector enters slot 5 in frame member 2 and the left hand side enters the lower slot in frame member 30. As the connectors are driven in the extending ribs 42, 43, which extend beyond the slots themselves, engage the wood of the frame members 2 and 30 and the mitred end faces 1 and 32 are drawn together drawing the frame members away from the guide fences 10 and 11 to form a right angled joint.

The joint formed is illustrated in Figures 3 and 4. Thus in the joint formed the two frame members 2 and 30 are held together with the faces of their mitred ends 1 and 32 held in contact to form an angle between of 900. The frame members are held firmly in this position by means of connector webs 40 within the common slot formed by the bringing together of slots 4 and 33 and the lower set of slots in the two frame members; the ribs 42 and 43 extending from web 41 of connector 40 having been driven into the frame members 2 and 30 holding the frame firmly together.

Claims

1. A method of forming a right angled joint between two members wherein the ends to be joined are mitred and wherein each member to be joined is provided, at the face to be joined, with a slot defined between flat mutually parallel surfaces and having an open side at the surface to be joined and an open end at the adjacent inside face of the member such that, when the members are placed with two faces together, the slots are mutually aligned to form a single slot which is common to the members and which has mutually parallel boundary surfaces defining opposite boundaries of the common slot, which method comprises positioning the members to be joined with the surfaces to be joined facing each other and substantially abutting to the outside of the joint to be made, the members being set at 90.50 to 920 to each other, and forcing, from the inside of the joint to be made and along the pair of corresponding slots in the members and between the members, a connector having a web and gripping formations on the web with at least one of the griping fornzi in engagement under pressure with one of the members and at least another of the gripping members in engagement under pressure with the other of the members, the pressure being sufficient to deform: the members and the engagement being such as to bring the members together at the interface.

2. Method according to claim 1 wherein the members to be joined are set at 90.50 to 924 to each other against guiderails or fences at a like angle with respect to each other and the connector is engaged in the slot by hydraulic or pneumatic drive means.

3. An assembly comprising two members joined by the method of claim 1 or 2.

4. An assembly according to claim 3 and which is a window frame.

5. An assembly according to claim 3 or 4 wherein the members are made of wood.

6. Apparatus for use in forming right angled joints which apparatus composes as pair of guiderails or fences set at 90.50 to 920 with respect to each other and, on the intersection of the angle formed between the guiderails or fences, means for holding a connector web and for advancing the connector web towards the angle to drive the connector web into pre-slotted members to be joined located against the guiderails or fences.

7. Apparatus according to claim 6 and including a carrier for one or more connector webs and drive means for advancing the carrier pneumatically or hydraulically to form the joint.

8. Apparatus according to claim 6 or 7 wherein the guiderails or fences are set substantially at an angle of 910 to one another.

9. Apparatus according to any one of claims 6 to 8 and including hydraulic or pneumatic means for holding the members to be joined adjacent the guiderails or fences with a force not so great as to prevent the members moving away from the guiderails or fences during formation of the joint.

10. A method of making a joint substantially as hereinbefore described with reference to the accompanying drawings.

11. Apparatus for making a right angled joint substantially as hereinbefore described with reference to the accompanying drawings.