A number of different types of connector for fastening two panels together at right angles to one another are known. A commonly used connector for fastening two panels together such that they can also be disconnected easily is known as a cam and dowel connector. This type of connector comprises two parts, an attachment pin or dowel, which is fixedly mounted in the face of a first panel, and a rotatable clamping pin which includes a cam track mounted in the other panel. There are a number of different arrangements of this type of connector available but they all operate in a similar manner in which the head of the dowel is inserted into the clamping pin and the pin is rotated such that the cam draws the head of the dowel into the clamping pin to pull the two panels together. This type of fastening provides an easily disengageable fastening but it has the disadvantage that the attachment pin extends out from the surface of the first panel. This is a particular disadvantage for panels of modular boxes as the pins are easily damaged or dislodged.

It is an object of the present invention to provide a connector that can be fully retracted within the plane of the part in which it is mounted when the connector is disengaged.

The invention provides a connector for disengageably fastening two parts together, comprising: retaining means in a first part;

a catch member inserted in an elongate hole in a second part, the catch member comprising an engagement portion having movable anchor means and an operating portion having operating means for moving the anchor means; and means to move the engagement portion and the operating portion along the elongate hole.

Preferably the retaining means comprises a collar inserted in a bore in the first part. Alternatively the retaining means may be integral with the first part, for example the retaining means may be a collar integrally moulded within a bore integrally moulded in a panel of plastics material.

Preferably the operating portion comprises a plunger portion having plunger means.

Preferably the second part further includes an access hole extending at right angles to, and into, the elongate hole.

Preferably the movement means moves the engagement portion and the plunger portion along the elongate hole towards and into the collar to engage the connector and moves the engagement portion and the plunger portion along the elongate hole away from the collar and back into the elongate hole to disengage the connector.

Preferably, as the engagement portion and the plunger portion are moved along the elongate hole to engage with the collar, the anchor means is moved into an engagement position relative to the collar. At this position, the engagement portion is preferably disengaged from the moving means while the plunger portion continues to be moved by the

moving means with respect to the engagement portion such that the plunger means is advanced between the anchor means within the collar to move the anchor means into engagement with the collar.

The collar is advantageously inserted in a bore in, for example, a panel or a corner post of a modular box or a furniture item or similar. The collar preferably has a self-tapping thread for insertion and fixing within the bore. Preferably the collar has an angled face for co-operation with the anchor means. The collar may advantageously be machined or die cast metal. It must be sufficiently strong and held within the bore with sufficient strength to withstand forces on the anchor portions of the connector which will tend to pull the two parts apart. Advantageously the collar comprises a cylindrical collar with a self-tapping thread on the outer surface of the cylinder and a smooth bore on the inside surface of the cylinder, the smooth bore extending to an angled face on the interior of the bore or on the inside end of the cylinder. Advantageously for a collar having an angled face on the interior of the bore of the cylinder, the bore in the panel is substantially the same depth as the collar. Alternatively, for a collar having an angled face on the inside end of the cylinder, the bore in the panel has a greater depth than the length of the collar.

The catch member is inserted in the elongate hole in, for example, a panel for attachment to the first panel or corner post. Preferably the elongate hole extends from the edge of the panel or a batten fastened to the panel and the access hole extends to the elongate hole from the face of the panel or batten.

The engagement portion and the plunger portion of the catch portion comprise two complimentary portions that are arranged in conjunction

with one another. The engagement portion preferably comprises a body portion attached to the anchoring means. The plunger portion preferably comprises a body portion attached to the plunger means. Preferably the plunger means is arranged within the anchor means and the respective body portions are arranged adjacent one another.

Preferably the anchor means comprises a two fingered collet. Preferably the end faces of the fingers are angled to co-operate with the angled face of the collar. The fingers are resilient such that the movement of the plunger through the anchor means causes the fingers to be forced outward and retraction of the plunger through the anchor means allows the anchor means to return to their original position.

Advantageously the fingers are formed with notches on their inner surface for engagement with corresponding ridges on the plunger means to indicate when the anchor means is in engagement with the collar.

Alternatively the notches may be formed on the plunger means and the ridges may be formed on the fingers. The co-operating notches and ridges also advantageously serve to retain the connector in the engaged position. The"click"as the ridge engages with the notch indicates to an operator that the connector is in the operable position. Additionally, some force is required to disengage the connector, thus reducing the risk of inadvertent disengagement. Advantageously a further set of co- operating notches is provided to serve as an engagement means with the ridges when the catch is retracted to withdraw the anchor means with the plunger means.

Preferably the elongate hole is dimensioned such that the catch means is within the panel when it is fully retracted.

Advantageously the catch means is formed with a protruding lug at its inner end to ensure correct alignment of the two catch components, anchor and plunger, during installation.

Preferably the plunger portion comprises a substantially cylindrical plunger that extends between the anchor means.

The body portion of the anchor means includes a disengagement portion such that, as the catch means is advanced by the movement means, the anchor means moves into position relative to the collar, the movement means then disengages from the anchor means but remains in engagement with the plunger means so that the plunger is advanced further between the fingers of the anchor portion, forcing the fingers apart. and into engagement with the collar to hold the two parts together.

The catch means is advantageously formed of injection moulded plastics, advantageously a polycarbonate material. Alternatively, the engagement portion may be formed of a polycarbonate material and the plunger portion may be formed of an acetal material, though any suitable materials may be used.

Preferably the body portion of the anchor means comprises teeth for engagement with the movement means.

Preferably the body portion of the plunger means comprises teeth for engagement with the movement means.

Preferably the respective body portions are formed as complimentary sections, each being half the thickness of the catch means and each having complimentary sets of teeth for engagement by the movement means, such that the movement means engages with both sets of teeth to move both the engagement portion and the plunger portion.

Preferably the movement means comprises a key having a splined shaft which is inserted through the access hole. Preferably the shaft is held in position within the access hole and is operated by a key means.

Preferably the shaft passes right through both body portions and engages with a co-operating hole in the panel to the rear side of the elongate hole.

This holds the shaft in position relative to the catch means.

Advantageously an insert sleeve is mounted in the co-operating hole.

Preferably the insert sleeve has a"click"fitting to indicate to an operator when the splined shaft is in engagement and/or to prevent inadvertent disengagement of the splined shaft.

When the shaft is rotated, the spline co-operates with the teeth in the body portions to move the catch means. When the spline reaches the end of the teeth section on the anchor portion, it moves into a free wheel position. The anchor portion thus does not move any further but continued rotation of the shaft causes the plunger portion to be moved further with respect to the anchor portion. This forces the plunger means between the fingers, moving them apart and into engagement with the collar.

To release the catch, the shaft is rotated in the other direction, thus retracting the plunger portion which allows the fingers of the anchor means to return to the disengaged position. As the plunger portion is

moved back, the anchor portion is pulled back with it, bringing the spline back into engagement with the teeth on the anchor portion and thus retracting both portions of the catch back into the elongate hole.

Because it is advantageous for a user to be able to operate the connector in a known direction, it is preferable for the elongate hole and the catch to co-operate in only one orientation. An advantageous arrangement for ensuring this is for the catch to have one side with a flat face and for the elongate hole to be"D"shaped in cross-section.

Advantageously the fingers form a split cylinder surrounding the plunger.

The invention will now be described by way of example only with reference to the drawings, of which: Figure 1 shows a connector according to the invention in side view, within two panels; Figure 2 shows a plan view of the anchor portion of the connector; Figure 3 shows a side view of the anchor portion of the connector; Figure 4 shows a plan view of the plunger portion of the connector; Figure 5 shows a side view of the plunger portion of the connector; and Figure 6 shows a cross-sectional view of a splined key and an access hole and an elongate hole for receiving the connector in a panel.

As shown in Figure 1, a connector 1 in accordance with the invention comprises a two part catch 2, a retaining means 3 and a movement means 4. The connector 1 can be used to disengageably connect together two parts 5,6 such as panels, posts or other elements of, for example, a box or a furniture item.

The retaining means 3 comprises a collar having a self-tapping thread 7 that is inserted into a bore 8 within the first part 5 which, in this example, will be described with reference to a corner post of a modular box formed from panels attached to each other via corner posts. The bore 8 is drilled within the corner post 5 and is of a diameter such that the self-tapping thread 7 of the collar 3 grips firmly within the bore 8. The depth of the bore 8 is of sufficient depth so that the bottom of the bore 8 does not interfere with the fitting of the collar 3. The inner face 9 of the collar 3 is formed as an angled face within the inner bore of the collar 3.

The catch 2 comprises two complimentary parts, an engagement portion 10 and a plunger portion 11. These are shown in more detail in Figures 2-5. The catch 2 is positioned in an elongate hole 13 in the part 6, which in this example will be described with reference to a panel or a batten fastened to the face of a panel for forming a modular box.

The engagement portion 10 comprises a body portion 12 and anchor means 14 in the form of a two fingered collet which forms a split cylinder having two sides, or fingers, 14a, 14b. The fingers 14a, 14b are formed of a resilient material such that they can be deformed outwardly by a force and will return to a rest position when the force is removed.

The plunger portion 11 comprises a body portion 15 and a plunger 16.

The plunger 16 fits within the fingers 14a, 14b of the anchor means 14.

The body portions 12,15 of the engagement portion 10 and plunger portion 11 respectively are each formed as approximately half the depth of the cylinder formed when the plunger 16 is positioned within the fingers

14a, 14b. Thus, the body portions 12,15 lie in adjacent relationship as part of the catch 2.

The body portions 12,15 have a U-shaped interior 12a, 15a respectively with teeth 17,18 formed on one surface thereof. The teeth 17,18 of the respective body portions 12,15 can be positioned in alignment for engagement with the movement means 4.

The movement means 4 comprises a splined key 19 having a shaft 19a with splines 19b that engage with the teeth 17,18 on the body portions 12,15. The shaft 19a is inserted through the body portions 12,15 through an access hole 24 (Figure 6) in the panel 6, the access hole 24 extending orthogonally to the elongate hole 13, and extending into the panel 6 on the far side of the elongate hole 13 to form a retaining bore 25 for the end of the splined shaft 19a. This enables the shaft 19a to be retained in position with respect to the catch 2 so that it does not dislodge.

In operation, to connect two parts 5,6 together, the collar 3 is inserted into the bore 8 in the post 5 and the catch 2, comprising the engagement portion 10 and the plunger portion 11 in co-operative engagement with each other, is inserted into the elongate hole 13 in the panel 6. The hole 13 is longer than the catch 2 such that the catch 2 can be fully retracted within the panel 6 when not in use. The length of the hole 13 is fairly critical as it is important that the catch 2 cannot move further than its withdrawal length to avoid the risk of the splined shaft 19a disengaging from the catch 2. The length of the hole 13 is determined by the relationship between the length of the catch 2 and the position of the orthogonal access hole 24 through the elongate hole 13.

A small lug 12b extends beyond the end of the body portion 12 of the engagement portion 10 to allow ensure correct alignment of the two catch components 10,11 during installation. The shaft 19a is inserted through the access hole 24 and through the interior portions 12a, 15a of the body portions 12,15 of the engagement portion 10 and the plunger portion 11 respectively. The splines 19b on the splined shaft 19a engage with the teeth 17,18 on the interior surfaces 12a, 15a of the body portions 12,15. A slight rotation of the shaft 19a will bring the shaft 19a into engagement from any entry orientation.

To operate the connector 1, post 5 is positioned adjacent the panel 6 with the bore 8 in alignment with the end of the elongate hole 13. The shaft 19a is rotated and the splines 19b on the shaft 19a engage with the teeth 17,18 to move the catch 2 forwards towards the end of the elongate hole 13 and into the collar 3. When the fingers 14a, 14b are inserted into the collar 3 far enough such that angled grip faces 20 at the ends of the fingers 14a, 14b are in alignment with the angled face 9 of the collar, the splines 19b of the shaft 19a slip into a free-wheel position 21 on the engagement portion 10. The splines 19b are still engaged with the teeth 18 of the plunger portion 11 and continued rotation of the shaft 19a will move the plunger portion 11 further forward. This forces the plunger 16 between the angled grip faces 20, moving them outwards until they engage with the angled face 9 of the collar 3. At this position, ridges 22 on the surface of the plunger 16 click into engagement with notches 23a on the interior surface of the fingers 14a, 14b. This"click"can be felt by an operator rotating the shaft 19a and thus gives an indication that the catch 2 has engaged with the collar 3.

When the connector 1 is thus engaged, the angled grip faces 20 act against the angled face 9 of the collar 3 to hold the two parts 5 and 6 together. The shaft 19a within the catch 2 holds the engagement portion 10 and the plunger portion 11 in position such that the catch 2 cannot be disengaged without an element of force on the shaft 19a to rotate it to retract the catch 2. The engagement of the ridges 22 and the notches 23a gives an additional retention force to prevent inadvertent disengagement.

To disengage the connector 1, the shaft 19a is rotated in the opposite direction to retract the catch 2. A certain degree of force is required to disengage the ridges 22 from the notches 23a to enable the catch 2 to be retracted. As the shaft 19a is rotated, the splines 19b engage with the teeth 18 on the plunger portion 11, moving it back into the elongate hole 13. As the plunger 16 moves back through the fingers 14a, 14b, the resilient fingers 14a, 14b spring back to their release position, disengaging the grip faces 20 from the angled face 9 of the collar 3. As the plunger portion 11 is retracted further, the ridges 22 engage with a rear set of notches 23b on the interior surface of the fingers 14a, 14b to move the engagement portion 10 back, thus moving the teeth 17 back into engagement with the splines 19b of the shaft 19a. Continued rotation of the shaft 19a moves both the engagement portion 10 and the plunger portion 11 back together into the elongate hole 13 until the catch 2 is retracted within the hole 13.

The notches 23b serve to engage the engagement portion 10 and the plunger portion 11 together for movement of the catch 2 and the notches 23a serve to indicate engagement of the catch 2 with the collar 3 and to prevent accidental disengagement of the connector 1.

When the two parts 5,6 are disconnected, none of the parts of the connector 1 extend beyond the surface of the parts 5 or 6, which allows any risk of damage to the connector 1 when the connector 1 is disengaged to be minimise.

Figure 6 shows the arrangement of the elongate hole 13 and the access hole 24 in the part 6. The part 6 is shown here as comprising a panel 6a and a batten 6b, fastened together. The elongate hole 13 extends into the batten 6b from the edge of the part 6 such that the catch 2 can be inserted into the elongate hole 13 lengthways. Because it is advantageous for a user to be able to operate the connector 1 in a constant direction, it is undesirable for the catch 2 to be able to be inserted into the hole 13 in either orientation and the hole 13, therefore, has a"D"shaped cross- section.

The access hole 24 for the splined key 19 extends from the face of the batten 6b, through the access hole 24 and into the retaining bore 25 on the inner face of the panel 6a. An insert sleeve 26 within the bore 25 engages a ridge 27 on the end of the shaft 19a to give a"click"fit, which serves to indicate to an operator that the shaft 19a is engaged and also prevents inadvertent disengagement of the key 19.

As shown in Figure 6, the splined shaft 19a has a head 28. The head 28 may have a particular pattern to correspond to a key such that rotation of the shaft 19a may only be carried out by an operator having a key corresponding to the particular pattern. This arrangement adds to the security of assembly of boxes, crates and so on.

The tolerances of the catch 2, the elongate hole 13, the access hole 24 and the shaft 19a are all closely defined to limit relative movement of the parts of the connector 1 and thus reduce any chances of inadvertent dislodgement of the separate parts of the connector 1 or disengagement of the connector 1 from its connected position.

The connector of the invention has many advantages over prior art connectors, particularly in that it can be easily engaged and disengaged when required and in that, when disengaged, all the parts of the connector can be within the plane of the panel or post in which they are mounted.