Field of the Invention The invention relates to a clamp, and more particularly, but not exclusively, to a one piece (or single unit) clamp for clamping together furniture/cabinet components.

Background of the Invention It is known to provide clamps for clamping together furniture components. For example, it is known to provide a clamping assembly for clamping together furniture components, wherein the clamping assembly has two clamping members which are drawn together by way of a threaded engagement. However, the applicant has identified that clamping assemblies of that type are not always suitable, as it is sometimes impractical to embed one clamping member in each of the furniture components. For example, the applicant has identified that such typical clamping assemblies may not be suitable for use in a 90 degree joint between panels of furniture.

The applicant has previously proposed a one piece clamp for holding together panels of furniture in a 90 degree arrangement, with a product marketed under the name "Zipbolt Fastfit". However, the applicant has identified that the Fastfit product has a relatively limited degree of tightening, and may not bite sufficiently into all materials. He has also identified that with the current trend towards the use of CNC Routers or Nesting Machines it would be beneficial for there to be provided an improved one piece clamp. ^*

Examples of the present invention seek to provide a clamp which overcomes or at least alleviates one or more disadvantages associated with previous clamps. Summarv of the Invention

In accordance with one aspect of the present invention, there is provided a clamp for clamping a first part to a second part, including a housing adapted to be retained relative to the first part, a shaft rotatably mounted to the housing, the shaft being threaded for threaded engagement with the second part, a first gear having a receptacle for receiving a tool and for transmitting rotation from the tool to the first gear, and a second gear for transmitting rotation from the first gear to the shaft, wherein the shaft slides relative to the second gear as the shaft is threaded into the second part.

Preferably, the threaded shaft is threadedly engaged with a mating thread in the housing, such that rotation of the shaft driven by the tool causes the shaft to move along a longitudinal axis of the shaft relative to the housing. Preferably, the housing is shaped to engage within a recess formed in the first part to retain the clamp housing relative to the first part.

In a preferred form, the shaft extends through a central aperture of the second gear, and the shaft and central aperture are shaped such that driving rotation of the second gear is transmitted from the second gear to the shaft. More preferably, the shaft has a non- circular cross-section, and the central aperture of the second gear has a non-circular cross- section corresponding to the cross-section of the shaft such that driving rotation of the second gear is transmitted from the second gear to the shaft. Even more preferably, the shaft has a hexagonal cross-section, and the central aperture of the second gear has a hexagonal cross-section corresponding to the cross-section of the shaft such that driving rotation of the second gear is transmitted from the second gear to the shaft.

Preferably, the first gear and the second gear are identical parts. In a preferred form, the clamp is adapted to provide a two stage clamping of the first and second parts, including a first stage in which the threaded shaft is driven into the second part maintaining an existing relative positioning of the first and second parts, and a second stage in which the first and second parts are clamped together, More preferably, the shaft has a rim which limits protrusion of the shaft beyond the housing during the second stage, and the shaft has a gap between the rim and a beginning of the thread to enable rotation of the shaft relative to the housing with the shaft at the protrusion limit without driving longitudinal movement of the shaft relative to the housing. Even more preferably, the gap is at least as large as a width of the housing.

Preferably, the housing is formed as two parts, with a cavity between the two parts to house the shaft and gears.

Brief Description of the Drawings

The invention is described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a clamp in accordance with an example of the present invention, shown without one half of a housing thereof; Figure 2 is a side view of an internal mechanism of the clamp;

Figure 3 is a perspective view of one side of the clamp, shown with one half of the housing removed; Figure 4 is a perspective view of the other side of the clamp, with the other half of the housing removed;

Figure 5 is a side view of the arrangement shown in Figure 4; Figure 6 is a side view of the arrangement shown in Figure 3; Figure 7 shows detail of the threaded shaft;

Figure 8 shows detail of two half portions of the housing; Figure 9 shows details of dimensions of the clamp;

Figure 10 shows an embodiment of the assembled clamp prior to use in clamping two parts; Figure 1 1 shows a clamp in accordance with another example of the present invention, and a furniture component;

Figure 12 shows a gear of the clamp shown in Figure 1 1 ; and Figures 13 to 1 8 show diagrammatic views of a clamp similar to the one shown in

Figures 1 1 and 12.

Detailed Description With reference to Figures 1 to 10, there is shown a clamp 10 which is suitable for use in clamping together furniture components, especially in a 90 degree arrangement of furniture panels as shown in Figure 10. The clamp 10 is embedded in a recess 26 formed in a first part 12 (of furniture panel), and is operated by way of a tool (for example an alien key) to drive a threaded shaft 18 of the clamp 10 into a second part 14 (or furniture panel). Advantageously, the clamp 10 is adapted to provide a two-stage tightening process wherein the first stage involves threaded engagement of the threaded shaft 18 in the second part 14, and the second stage involves drawing together of the two parts 12, 14.

More specifically, the detailed operation of the clamp 10 is described with reference to Figures 1 to 9. These drawings show a clamp 10 for clamping the first part 12 to the second part 14, including a housing 16 adapted to be retained relative to the first part 12. The clamp 10 also includes a shaft 18 rotatably mounted to the housing 16, the shaft 18 being threaded for threaded engagement with a bore 19 in the second part 14. The clamp 10 also includes a first gear 20 and a second gear 22 for transmitting drive from a tool to the shaft 18. More particularly, the first gear 20 has a receptacle 24 for receiving a tool and for transmitting rotation from the tool to the first gear 20, whereas the second gear is for transmitting rotation from the first gear 20 to the shaft 18. The shaft 18 slides relative to the second gear 22 when the shaft 1 8 is threaded into the second part 14.

As can be seen in Figure 1 , the threaded shaft 18 is threadedly engaged with a mating female thread in the housing 16, such that rotation of the shaft 18 driven by the tool causes the shaft 18 to move along a longitudinal axis of the shaft 18 relative to the housing 16. In this way, the shaft 18 is positively driven outwardly of the housing 16 when the first gear 20 is rotated. The housing 16 is shaped to engage within the recess 26 formed in the first part 12 to retain the clamp housing 16 relative to the first part 12. As can be seen in Figure 10, the housing 16 has a bulbous circular end which is unable to pass through a narrow throat 27 of the recess 26, such that the housing 16 is effectively retained relative to the first part 12. Returning to the mechanical operation of the clamp 10, the shaft 18 extends through a central aperture 28 of the second gear 22, and the shaft 18 and central aperture 28 are shaped such that driving rotation of the second gear 22 is transmitted from the second gear 22 to the shaft 18. The shaft 18 has a hexagonal cross-section along part of its length, and the central aperture 28 of the second gear 22 has a matching hexagonal cross- section corresponding to the cross-section of the shaft 18 such that driving rotation of the second gear 22 is transmitted from the second gear 22 to the shaft 18. Although the example shown in the drawings depicts the cross-section of a proximal portion of the shaft 18 to be hexagonal and the matching cross-section of the central aperture 28 to also be hexagonal, it will be understood by those skilled in the art that other non-circular cross- sectional shapes would also serve the purpose of transmitting driving rotation from the second gear 22 to the shaft 18 (for example, a square cross-section, triangular cross- section, an oval cross-section, etc).

Advantageously, in the example shown in the drawings, the first gear 20 and the second gear 22 are identical parts. This is beneficial as it reduces the total number of different parts that need to be manufactured to form the clamp 10. As the first gear 20 is identical to the second gear 22, the receptacle 24 of the first gear 20 is of the same dimensions as the central aperture of the second gear 22, and the hexagonal proximal portion of the shaft 18 is therefore of the same cross-sectional dimensions as the alien key tool used to engage the first gear 20.

As seen clearly in Figure 2, the first gear 20 is tilted downwardly from the second gear 22 toward the shaft 18 to improve access to the receptacle 24, particularly when the clamp 10 is to be used close to a 90 degree joint of panels which may otherwise inhibit the operator's accessibility to tighten the clamp 10.

The clamp 10 is adapted to provide a two stage clamping of the first and second parts 12, 14. These two stages include a first stage in which the threaded shaft 18 is driven into the second part 14 maintaining an existing relative positioning of the first and second parts 12, 14, and a second stage in which the first and second parts 12, 14 are clamped together. The shaft 18 has a rim 30 which separates the hexagonal proximal portion of the shaft 18 and the threaded distal portion of the shaft 18. The rim 30 limits protrusion of the shaft 18 beyond the housing 16 during the second stage. The shaft 18 also has a gap 32 between the rim 30 and a beginning of the thread to enable rotation of the shaft 18 relative to the housing 16 with the shaft 18 at the protrusion limit without driving longitudinal movement of the shaft 18 relative to the housing 16. The gap 32 is at leas as large as a width of the housing 16 at the distal wall of the housing 16.

The applicant has identified that without the gap 32, the thread of the shaft 18 would be threadedly engaged with the female thread formed in the distal wall of the housing 16 even when the rim 30 abuts against the distal wall with the shaft 18 at its protrusion limit. If that were the case, the shaft 18 would cease to be able to rotate relative to the housing 16, and it would not be possible for further rotation of the shaft 18 to draw the second part 14 closer to the first part 12 in a clamped abutment. In the preferred embodiment shown, the housing 16 is formed as two parts, with a cavity between the two parts to house the shaft 18 and gears 20, 22. The two parts are held together by way of pins of one part which extend through apertures formed in the other part, with the pins flared to prevent the two parts from coming apart. In an alternative example, one part of the housing may be formed with shorter pins and the other part may be formed with limited depth recesses/bores (rather than through holes), and the two parts may be held together by a friction fit (of the pins within the recesses/bores) and/or with the assistance of glue.

With reference to Figures 1 1 to 18, there is shown a clamp 10 in accordance with an alternative example of the present invention which includes various modifications over the clamp shown in Figures 1 to 10. In particular, Figures 1 1 and 12 show that the housing 16 and the gears 20, 22 are made of metal. More specifically, the housing 16 is formed as two half shell portions, with each half being formed by die-casting Zamak material, which is an alloy with a base metal of zinc and alloying elements of aluminium, magnesium and copper. Although Figure 1 1 shows the tip of the shaft 18 protruding from the housing 16 when in the fully retracted state, in other examples it may be possible to fully retract the shaft 18 so that the tip of the shaft is flush with the housing 16. The shaft 18 may be formed from mild steel. Figure 12 shows a gear which may be used for both the first gear 20 and the second gear 22, such that the first gear 20 and the second gear 22 are formed of interchangeable identical parts. The gear may be formed of alloy steel, with high carbon content for toughness. One face of the gear may be flat, with the opposite face having a slight convex curvature to assist in keeping the gear snug within the housing 16, and to ensure the gear can only be inserted in the correct orientation. The gear may have seven teeth, and each of the teeth may be rounded. The rounding of the teeth may assist in compensating for slight shape variations caused during the stamping production process, to ensure that the gears operate smoothly even with minor manufacturing variations. The metal teeth of the metal gears may be significantly stronger than gears formed of plastic material, and may also provide good resistance to unwanted creep and compression.

With reference to Figures 13 to 18, there are shown various views depicting changes made to the internal configuration of the housing 16 to accommodate (and complement) the curved gears 20, 22 of the kind shown in Figure 12. The general configuration of the clamp 10 shown in Figures 13 to 18 is similar to the configuration of the clamp 10 shown in Figures 1 to 10, and like features are labelled with like reference numerals. The main difference resides in that the housing 16 includes cavities 34 which are correspondingly tapered to house the gears 20, 22 having curved faces. As can be seen in Figure 13, the curved face of the first gear 20 faces away from the shaft 18, and the curved face of the second gear 22 faces toward the threaded end of the shaft 18. The housing 16 also has an additional support partition 36 which, in use, sits between the second gear 22 and the rim 30.

Specifically, Figure 13 shows a left-hand shell portion 38 of the housing 16 with the shaft 18 fitted therein, Figure 14 shows the left-hand shell portion 38 with the shaft 18 removed, Figure 15 shows cavity detail of the left-hand shell portion 38, Figure 16 shows cavity detail of a right-hand shell portion 40, Figure 17 shows the right-hand shell portion 40 with the shaft 18 located therein, and Figure 18 shows detail of the right-hand shell portion 40 with the shaft 18 and the second gear 22 mounted therein. The length of the hexagonal portion of the shaft 18 may be tailored to ensure correct seating within the second gear 22 when the shaft 18 is fully extended.

While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not by way of limitation. It will be apparent to a person skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus, the present invention should not be limited by any of the above described exemplary embodiments.

In particular, the threaded engagement of the shaft in the second part could, in an alternative example, be by way of threaded engagement of the shaft in a nut (or other body) embedded in the second part. Also, the shaft could be shaped with an oval cross- section which is received in an oval hole in the second part such that when the shaft is rotated (for example by 90 degrees) the shaft is tightly retained within the hole. . The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.