EXPANDABLE CONNECTOR ASSEMBLY, TOOL ATTACHMENT

AND WORKPIECE JIG

FIELD OF THE INVENTION

THIS INVENTION relates to joinery and particularly to joinery employing

an expandible connector and more particularly but not limited to joinery

employing a kit comprising a tool and connector.

BACKGROUND TO THE INVENTION

Expandible connectors are known. The connectors are often of plastics and are inserted into a hole and usually employ a rigid expander, often a screw which is driven into the connector to expand the connector into gripping

engagement with the hole. Most often the connector is elongate and the

expander is driven into the connector in the longitudinal direction of the connector. While this type of connector is useful it has limited application where it is desirable to pull two pieces being joined together. Connectors that apply a

force to draw two objects together while connecting are also known. One

example is cam connector where a slotted cam is held in a transverse hole, it engages a rod through a side hole and upon rotation of the cam the parts are pulled together.

It is an object of the present invention to provide an expandible connector which is able to draw parts together.

It is a further object to provide an expandable connector insertable into

opposed aligned slots where the slots have a narrow entry.

OUTLINE OF THE INVENTION

In the present case there is provided a kit where the parts of the kit are

independently inventive but in the preferred form are matched to each other to

provide a matching slotting tool and associated connector. Thus one invention

is to a tool, another invention is to a connector and another invention is to a kit

comprising a tool and a connector.

Furthermore there is provided a tool for forming a slot for a particular

connector and to a method and apparatus for forming the slot and, in particular,

but not limited to, a method and apparatus for forming a dovetail slot by routing and an associated expandible dovetail connector.

In one broad aspect therefore there is provided a slot and connector assembly whereby mating slots formed according to the method may be aligned

and connected using an expandable connector.

In one preferred form there is provided a slot and connector assembly whereby mating slots formed according may be aligned and connected using an expandable connector, the expandable connector having opposite sections, at

least one being an expandable section and the sections being locatable in

respective confronting slots of opposed workpieces forming a joint using the connector, the expandable section having an opening to receive an expander

and there being an expander forcible into the expandable section, the slots

mating to form opposite dovetails, the connector being generally X -shaped in

cross section and the expander being generally U-shaped in cross-section with

legs insertable into the connector. Preferably, the expandable sections comprise

dovetail sections with respective expansion holes.

In addition there is provided a means for placing a workpiece in position

so a slot may be formed. The means for placing a workpiece in position may is

typically a portable workpiece alignment tool and preferably comprises a jig

having a clamp. The jig may be part of the tool. Thus the tool may comprise a

jig with an integral router or a jig with a router attachment.

In another broad aspect therefore there is provided a method and

apparatus for forming a slot in a workpiece, an expandable connector and an

assembly of same, the connector having opposite expandable sections and

being locatable in respective confronting slots of opposed workpieces forming

a joint using the connector, each expandable section having an opening to

receive an expander and there being an expander forcible into the expandable sections, the method comprising positioning the workpiece with respect to a

router tool in a portable workpiece alignment tool, and routing a slot to match the

expandable sections, the portable alignment tool having a router tool opening and means to position the workpiece in predetermined relation to the router tool while the slot is being formed. Subject to the slot being formed the router tool or

the workpiece may be fixed relative to the other.

The particular workpiece alignment tool may have a dedicated router mounted so that the router tool may be moved on a suitable guide means to

perform the slot forming operation.

The workpiece alignment tool may have one or more workpiece clamps.

It may have one or more workpiece guides. Typically, the alignment tool

comprises a guide for forming slots in mitred joints. In addition, it is preferable

to include a guide for forming slots for butt joints. In another embodiment the

guide is reversible having one position forming slots for mitred joints and

another position for forming slots for butt joints. In another embodiment

longitudinally extending slots may be formed in an edge of the workpiece by

sliding the workpiece along the alignment tool.

The slots may be formed as short transverse slots or may be formed as

longitudinally extending slots. In the case of mitred joints, the slots may be

formed in workpieces having non-straight or non-flat profiles using an adjustable

support. For example, in the case of decorative mouldings, the moulding may be supported by using a slidable wedge to support the non-straight or non-flat portion. The slidable wedge is preferably mounted to travel in a transverse guide

way. The slot is typically a blind slot so that the connector may be inserted into

the slot from the rear of the workpieces being joined and consequently the

connector is a concealed connector not visible from the front.

In another aspect there is provided an expandable connector having opposite sections, at least one being an expandable section and the sections

being locatable in respective confronting slots of opposed workpieces forming a joint using the connector, the expandable section having an opening to receive

an expander and there being an expander forcible into the expandable section.

Preferably, both sections are expandable and the expander comprises

respective expander sections which are simultaneously insertable into both

expandable section at once.

The expandable sections preferably comprise dovetail sections so the

connector is generally cross or X shaped. The connector preferably has a slot

entry end and an opposite flat outer end that may be located just below or flush

with the workpiece surface adjacent the slot. The entry end is typically concave.

Each expandable section preferably includes an expander locator which is

preferably a slot having recessed side walls the expander being locatable in the

recess.

The expander is typically U-shaped having legs insertable into the

expandable sections. The legs are preferably braced. The expander preferably includes a cap matched to the outer end to cap the outer end.

In a further aspect there is provided a connector assembly comprising a

connector and expander as broadly described above and preferably having the

preferred features set out above. fn a still further broad aspect there is provided a kit comprising a connector and tool as broadly described above. Typically the tool and connector

have the preferred features as set out above.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the present invention may be more readily understood and

be put into practical effect, reference will now be made to the accompanying drawings and wherein:-

Figures 1 and 2 are examples of slotted workpieces adapted to and

aligned to receive a connector described below;

Figures 3, 4, 5 and 6 are respective elevation, plan, end and underside

views of an expandable connector;

Figures 7 and 8 are respective side and plan views of an expander for the

connector of Figures 3 to 6;

Figure 9 is a side view showing the expander of Figures 7 and 8 partially

inserted into the connector of Figures 3 to 6;

Figures 10, 11 and 12 are respective plan and side views of a hand tool

for forming a slot of the type illustrated in Figures 1 and 2;

Figure 13 is a perspective view of the tool of Figures 10 to 12; Figure 14 is a perspective drawing of another embodiment, in this case

a clamp (shown in its released position in Figure 14) for aligning a workpiece for

the formation of a slot of the type illustrated in Figures 1 and 2;

Figure 15 is a perspective drawing illustrating the clamp of Figure 14 with

a workpiece clamped in position and the slot having been cut, noting that a 45°

guide is employed so that one half of a mitred joint is formed, a second 45° guide is located opposite so a slot may be cut in the opposite mitre;

Figure 16 illustrates the clamp of Figures 14 and 15 with the guide reversed;

Figures 17, 18 and 19 are respective plan, side and end views illustrating

an alternative embodiment of the clamp; and

Figures 20 to 22 are respective side plan and end views of a clamping aid suitable for use with the embodiment of Figures 14 to 16.

METHOD OF PERFORMANCE

Referring to the drawings and initially to Figures 1 and 2, there is

illustrated in Figure 1 workpieces 10 and 11 aligned to form a butt joint whereby

the workpiece 10 has a dovetail slot 12 and the workpiece 11 has a dovetail slot

13 which clearly, if filled by a connector, will hold the two parts in the butt joint

position.

Figure 2 illustrates workpieces 14 and 15 forming a mitred joint where

slots 16 and 17 are aligned in similar fashion to the slots 12 and 13 of Figure 1.

In order to secure the workpieces of Figures 1 and 2 together, an expandable

connector is employed and this expandable connector utilises an expander so

that when the expandable connector is inserted into the slots and expanded it

pulls the two workpieces together and removes any slack in the joint.

A typical connector is illustrated in Figures 3 to 9. Referring to these

drawing figures there is illustrated a connector 18 and an expander 19,

expander 19 having a capped section 20 and spaced legs 21 and 22 while the connector 18 has an X shaped body 23 comprising wings 24, 25, 26 and 27

whereupon insertion of the expander into apertures 28 and 29 between the

respective pairs of wings causes the wings to pivot outward and inward in the direction of the arrows shown thus pulling a joint together.

In order to form a slot of the type illustrated in Figures 1 and 2 in a workpiece a number of tools are employed and Figures 10 to13 illustrates a

hand held tool comprising a workpiece alignment means in the form of plate 31 having a flange 32 such that plate 31 and flange 32 sit at right angles and may

be positioned over a corner of workpiece. A router head 33 is adapted to travel through a slot 34 in the plate 31 and cut a slot of the type illustrated in Figures

1 and 2 in the aligned workpiece.

The router head is driven by a motor 34 on a carriage formed by guide

rails 35 and 36 and guide ways 37 and 38 so that the router head may be moved

manually back and forth in the direction as illustrated by arrow 39 in Figure 13.

A workpiece is illustrated in phantom at 40 in Figure 13. It will be appreciated

that by movement of the router motor along the guide and guide ways that a slot

according to the present invention would be cut in the workpiece.

An alternative is illustrated in Figures 14, 15 and 16. In this case a

greater variety of workpieces may be cut while still being portable, a clamp

assembly 41 comprises a router guide plate 42 having a router tool opening 43,

a workpiece guide plate 44 having 45° guides 45 and 46 so that opposite mitres

may be cut using the guides 45 and 46. The clamp 41 may be mounted on a

bench adjacent a bench router so that upon alignment of a workpiece in position adjacent to opening 43 the press may be used to form the slot in the workpiece.

The assembly has a clamp 47 comprising a handle 48, cams 49 and 50, a clamp

bar 51 and spring mountings 52 at opposite ends. This enables a workpiece to be clamped when the handle 48 is pulled down to a position running generally

parallel to the guide 44. Thus a workpiece is slid along one of the 45° guides into alignment with the slot 43 and then the clamp is applied to hold that piece in position for the slot cutting process. The guide plate 44 is travelling in a guide

set at 90° to the plate 42 and consequently the clamp handle 52 for the guide

is offset relative to the central guide way for the plate 44.

While the clamp and guide may be utilised in relation to rectangular

workpieces, in many cases for a mitred joint it is desirable to form a mitred joint

in a decorative workpiece and consequently the alignment process for a

decorative workpiece in this case involves wedges 53 and 54 which may slide

and the wedge may then be used in conjunction with the clamp bar 51 to support

the workpiece in its position to cut the slot.

Figure 15 illustrates a workpiece 55 in position, a slot 56 having been cut

using a suitable bench router. As an alternative to a bench router, a router

similar to the arrangement illustrated in relation to Figures 10 to13 may be

formed on the outside of the plate 42 with suitable guides so that a dedicated

router may be used with the clamp arrangement 41 so that there is fixed

geometry between the router and the clamp so that the slots may be cut.

Referring to Figure 16, it will be clearly seen that the guide plate 44 has

been reversed such that its rear edge 57 provides a support for a workpiece slid

into the clamp for the purpose of cutting a slot for a joint of the type illustrated

in Figure 1. That is, slot 13 may be cut by removing wedges 53 and 54 and pushing the edge 57 up against the workpiece to secure it relative to the slot 43.

In another embodiment, the clamp 47 may be completely removed and the holes

utilised for that clamp may be used to secure a holdfast or other clamp to apply downward pressure to a workpiece.

Another embodiment is illustrated in Figure 17 and as can be seen many of the elements of this embodiment are similar to those of Figures 14 to 16. However, the clamp in this case at 58 may be used to clamp either a workpiece

in the mitre arrangement or alternatively a workpiece slid in from the left to

secure a workpiece for the cutting of a slot suitable for a butt joint. In another case the router tool may be held fixed projecting through the opening 43 and the

workpiece slid along to cut a slot.

As an alternative to the above described operation of the embodiments

of 14 and 15 as described in relation to Figure 16, a clamping aid according to

Figures 20 to 22 may be utilised underneath the clamp 47 with the wedges 53

and 54 removed and the guide plate 44 in the reverse configuration of Figure

16. The clamping aid is used to apply downward pressure on a workpiece

running hard up against the plate 42 and parallel to the clamp bar 51. The

clamping aid 60 has a recess 61 matching the cross section of the clamp bar 51.

The clamp bar 51 is shown in phantom at 62. The clamp aid 60 effectively

operates as a lever having a fulcrum at 63 and a clamp head at 64 so that a part

operation of the handle 48 the clamping portion 64 applies downward pressure

on to a workpiece 65 shown in phantom forcing it down on to the bed of the clamp of Figure 16 while the plate 57 bears against the workpiece which in turn

is held against plate 42, thus the combination of the plate 42, the bed of the

apparatus, the plate 47 and the point contact of the clamping head 64 secures

the workpiece 65 in place, such that a slot may be cut in a workpiece 65 held in this position. It will be appreciated that a slot may be cut transversely in the

workpiece 65, or the workpiece 65 may be slid with sufficient clamping force to enable close sliding so that a longitudinal slot may be cut.

Whilst the above has been given by way of illustrative example of the

present invention many variations and modifications thereto will be apparent to those skilled in the art without departing from the broad ambit and scope of the

invention as set out in the appended claims.