SUPPORT CLAMP

The present invention relates to a clamp, in particular a clamp for holding a door or window frame for example in a free-standing position as a work-piece. More particularly, the invention relates to a door clamp to provide support during painting, sanding, mending, the attachment of fittings or other form of treatment.

In order to complete the aforementioned or other works the door needs to be held in a vertical plane procuring the door edge, on which the attachment of fittings is performed, substantially horizontal to the floor.

One traditional method of maintaining a door in the correct orientation enabling fitting, is to employ a second person to provide support for the door. However, this is labour intensive. Even when a single person is employed, it can be inconvenient or awkward for one person to maintain the door in a stable orientation for working.

In view of this problem, attempts have been made to provide a form of bracket to hold the door in a stand alone position.

Clamp stands have since been designed in an attempt to overcome these problems.

GB2405119 discloses a clamp for a door comprising; first and second clamp surfaces, a base plate, in which the clamp surfaces are supported and able to move with respect to each other, and a locking means for locking the clamp surfaces when desired. The clamp may be adjustable by height via the provision of movable feet and include one or more spirit levels. Synthetic materials such as plastic can be used on the second side wall of the slotted recess and the feet to prevent marking of the door.

GB2420736 discloses a support clamp for clamping a door or window frame, for example a door comprising a wedge member, a support means, and a base arranged to support both the wedge member and the support means. The wedge member has a first side wall of the slotted recess and a wedge surface inclined at a wedge angle, whilst the support means provides a second side wall of the slotted recess. The base includes a recess with a wedge guide wall inclined at the wedge angle to the second side wall of the slotted recess, A planar object may be clamped between the first side wall of the slotted recess and the wedge member, and by applying a force in a specific direction to the wedge member along the guide wall.

GB2398265 discloses a door stand including a base and locking pin, which can be used to hold a door in an upright position so that various work can be carried out on it such as to plane a door to fit a recess, cutting out for locks, hinges and recessed bolts. This invention fails to disclose a clamp stand that prevents

damaging the door during clamping, as there is no means of protection either side of the clamp stand

GB2275880 A discloses a vice having two components, a cradle and a wedge A door is laid on its edge into the housing of the cradle and the wedge is then driven alongside the door also into the housing of the cradle, so that it tightens the door to the cradle which will then leave the door free standing to enable a "hands free" situation for planing and fitting of hinges or locks etc

US2005/0173854 A1 discloses a clamp holding a door or window frame for example such as a door The clamp comprises a body shaped to define a recess for receiving a portion of the door or window frame and a wedge which is movable within the recess in order to clamp the door or window frame, between the wedge and the body The wedge and the body are coupled together by means of a coupling mechanism which allows the wedge to adopt a use state, in which the wedge may be moved through the recess, and a storage/transport state in which the wedge is generally co-planar with the body In the preferred embodiment, the coupling mechanism comprises a guide member mated with an elongated aperture

GB2413352 discloses a kit comprising a block having a transverse slot into which a door may engage, with a wedge being provided for insertion into the slot against a face of the door to support the door

EP1125690 discloses an urging system for a jaw of a vice comprising an L- shaped block having slots adapted to be engaged by pins affixed to the jaw, and having a member shaped as an inverted right trapeze which allows displacement and locking of the jaw onto the L-shaped block.

Many of these prior art clamps suffer from a lack of simplicity, leading to increased cost of manufacture and increased maintenance and "wear & tear" problems, or from over-simplicity, leading to problems of damaging door and/or window frame objects mounted therein. Many also are designed in such a way as to allow vertical movement of the wedge during use. This movement quite often results in damage to the surface of the object on which work is being carried out, or may give rise to instability in the object.

It would be advantageous for a clamping device designed for use when working on doors or similar planar objects, to be quick and effective to use, and readily transportable and storable, in addition to being relatively inexpensive, while protecting the door from damage, with convenient storage capability for tools, and which prevented any vertical movement of the wedge during use.

It is an object of the present invention to provide an improved form of support clamp for supporting a door or window frame for example in a maintenance position.

According to the present invention there is provided a support clamp for a substantially planar work-piece, the support clamp comprising a base structure for mounting or resting on a floor or other work surface and a wedge member. The base structure has an elongate body with a transverse groove therein, the groove being adapted to receive the work-piece in an erect orientation, the groove having a first sidewall substantially parallel to the transverse axis of groove, and a second sidewall arranged at a convergence angle with the transverse axis of the groove so that the groove has a substantially trapezoidal plan. The second side wall of the base structure is angled with respect to the longitudinal axis of the groove. The wedges member is similarly trapezoid in plan and is angled along one edge such that it mirrors the angle of the second sidewall of the base and so that it can be received in the groove in clamping engagement with a work-piece mounted therein.

The corresponding, angled edges of the base and the wedge are such that, when a work-piece is mounted in the base and the wedge is inserted, the wedge is prevented from moving in a vertical direction because the angle of the slope is such that the width of the wedge at its base is greater than its width at the top.

Both the angle at which the second side wail of the base meets the base and the angle of one face of the wedge are acute and, preferably, less than about 88°,

more preferably less than about 87°, still more preferably less than about 86° and most preferably less than about 85°.

The support clamp of the invention is advantageous in the simplicity of its design. A door, window frame or other substantially planar work piece may be mounted in the groove in a standing-up orientation adjacent the non-angled sidewall, and the clamping member then driven into the groove to secure the work-piece between the clamping member and the non-angled sidewall.

Preferably, the wedge shaped clamping member is itself substantially trapezoidal in plan shape, and the insertion end of the clamping member has an end surface area large enough to present and adequate target for a hammer or the like when the clamping member is to be removed from its clamping position.

The wedge may be provided with a strike plate attached to the narrow end, thereby strengthening the surface, in order to minimise the risk of damage to the wedge shaped member, and the work-piece, during its removal.

The support clamp may be provided with an insert member adjacent the first sidewall of the groove. Different sizes of insert member may be used to alter the width of the groove to accommodate different size work pieces.

The work piece will typically be a door or window frame.

The support clamp may be provided with a resilient material padding one or both sidewalls, and/or the clamping member The resilient material may for example be rubber or other suitable synthetic material, such as dense polyurethane foam for example The use of a resilient material in this way allows the support clamp of the invention to be of relatively simple and straightforward manufacture, and yet to afford the work-piece mounted therein a degree of protection from damage during clamping, particularly in the robust conditions of the workplace such as a construction or renovation site In the case of the support clamp being provided with an insert member, the insert member may be have a resilient surface for presentation to the work piece, to prevent damage thereof in use of the support clamp In this case the resilient material is provided by incorporating a block of such material (ιe an insert member) into the groove of the base unit

The resilience of the one or both side walls (and/or the wedge shaped member) allows improved gripping of the work piece whilst minimising the danger of damage thereto during the clamping procedure

Preferably, the base unit is elongate and comprises a substantially oblong block with the groove (or slotted recess) cut or machined therein The slotted recess is preferably provided towards the central region of the block so that when the door or window frame is mounted therein effective supporting block sections extend either side of the mounted door

Preferably the base of the clamp provides a wedge storage groove, wherein the groove begins at one end of the second side wall of the slotted recess, so as to provide a corner at said end of the second wall of the slotted recess. The wedge shaped member can rotate around said corner, thereby slotting into a storage position, within the wedge storage groove, by way of being pushed back, the wedge providing a pin aperture, said aperture being slotted over a pin situated in the end wall of the wedge storage groove, securing the wedge to the clamp base, thereby adopting a transport/storage state.

Preferably the main body of the clamp and the wedge member comprise wood, although any suitable material, such as metal, plastic, composite materials or combinations thereof may be used.

An embodiment of the present invention is described by way of example with reference to the accompanying drawings, wherein;

Figure 1 schematically shows a plan view of the support clamp of the present invention, wherein the wedge member is in the storage position;

Figure 2 schematically shows a plan view of the support clamp of the present invention, wherein the wedge member is released from the storage position;

Figure 3 schematically shows a plan view of the support clamp of the present invention, wherein the wedge member is rotated towards the use position;

Figure 4 schematically shows a plan view of the support clamp of the present invention, wherein the wedge member is in the use position;

Figure 5 schematically shows a perspective view of the near side of the support clamp of the present invention, wherein the wedge member is in the use position;

Figure 6 schematically shows a perspective view of the far side of the support clamp of the present invention, wherein the wedge member is in the use position;

Figure 7 schematically shows a perspective view of the near side of the support clamp of the present invention, wherein the wedge member is removed from the clamp stand;

Figure 8 schematically shows a perspective view of the far side of the support clamp of the present invention, wherein the wedge member is removed from the clamp stand;

Figure 9 schematically shows a perspective view of the support clamp of the present invention in the use position with a door inserted into the slotted recess.

Referring to Figures 1 to 9, there is provided a clamp (1) comprising a base (2) having an angled first wedge guide wall (3) and a second, acute angled side wall (4) of the slotted recess (18), arranged to receive a door or window frame for example. Foam, rubber, or similar fabric are disposed in a block formation on at least one of the horizontal inner surfaces of the recess (6), so as to prevent marking the door or window frame clamped within the recess. A wedge (7) is driven into position from its thickest end (10) between a door or window frame (5) and the wedge guide wall (3); the opposing face of the door or window frame (9) is forced into close proximity to the second clamping wall (4). As the proximity between the opposing face (9) and second clamping wall (4) decrease, the door or window frame (5) becomes stable in an upright position (11), allowing workmanship to be performed on the door or window frame. The clamped wedge (7) is removed out of position from its thinnest end (12) releasing the door or window frame.

During storage or transportation of the clamp the wedge (7) may be placed in the wedge groove (13), and fixed in the storage position with a pin (14), for example a metal pin, by means of slotting the pin (14) into the pin sized hole (15) present on the large end of the wedge (10) whereby avoiding the misplacement of essential elements to the invention.

The clamp (1) may provide tool grooves (16) and one or more screw trays (17) whereby aiding workmanship on said object.

The clamp (1) may comprise one or more gripping feet (19) whereby aiding the grip between the clamp stand and the floor.

The wedge shaped member (7) may comprise one side wall grooved at an acute angle (20), whereby slotting over the acute angled second side wall (4) of the slotted recess (18) providing an improved closeness of association between the wedge shaped member (7) and the second side wall (4) of the slotted recess (18).

The door is lowered by a single person into the recess of the clamp and lined up against the first side wall of the slotted recess (3) and the straight edged side (21) of the wedge shaped member (7). The wedge is then driven into position from its widest end (10) along the first wedge guide wall (22) using a hammer until the door is in a stable upright position On completion of the work the wedge is then driven out of the recess and along the door face (9) by way of hitting the thin end of the wedge (12) with a hammer until the wedge is disengaged.