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Patent Searching and Data


Title:
A CLAMP APPARATUS
Document Type and Number:
WIPO Patent Application WO/2004/106005
Kind Code:
A1
Abstract:
The present invention provides clamping apparatus (2) for holding an item (42) in a generally vertical plane, the apparaws (2) comprising two members (4, 6) for clamping about an item (42), and biasiing means (32) for biasing the two clamping members (4, 6) from a clamping position towards a release position wherein the distance between the clamping members is greater in the release position than in the clamping position. Apparatus which may be conveniently used to both clamp and subsequently release an item is thereby provided.

Inventors:
CHURCHMAN TIMOTHY MICHAEL OLIV (GB)
Application Number:
PCT/GB2004/002312
Publication Date:
December 09, 2004
Filing Date:
May 28, 2004
Export Citation:
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Assignee:
CHURCHMAN TIMOTHY MICHAEL OLIV (GB)
International Classes:
B25B11/00; E04F21/00; (IPC1-7): B25B11/00; E04F21/00
Foreign References:
US1598520A1926-08-31
US2971548A1961-02-14
US1715722A1929-06-04
US1130975A1915-03-09
US0962376A1910-06-21
US0848837A1907-04-02
Attorney, Agent or Firm:
URQUHART-DYKES & LORD LLP (21-27 Newport Road, Cardiff CF24 0AA, GB)
Download PDF:
Claims:
Claims
1. A clamp apparatus for holding an item in a generally vertical plane, the apparatus comprising two members for clamping about an item; and biasing means for biasing the two clamping members from a clamping position towards a release position wherein the distance between the clamping members is greater in the release position than in the clamping position.
2. A clamp apparatus as claimed in Claim 1, wherein said biasing means mechanically secures the two clamping members to one another.
3. A clamp apparatus as claimed in Claim 2, wherein said biasing means mechanically secures the two clamping members to one another so that said members are rotationally moveable relative to one another between the clamping position and the release position.
4. A clamp apparatus as claimed in Claim 2 or 3, wherein said biasing means if adjustable in such a way as to allow the distance between the clamping members, when said members are in the release position, to be selectively varied.
5. A clamp apparatus as claimed in Claim 4, wherein said biasing means is telescopically mounted to one of the clamping members.
6. A clamp apparatus as claimed in Claim 5, wherein the clamping member to which said biasing means is telescopically mounted is provided with means for selectively securing said biasing means to said clamping member.
7. A clamp apparatus as claimed in Claim 1, further comprising means for allowing the bias of the biasing means to be overcome when, in use, an item to be clamped is rested on said apparatus between the clamp members.
8. A clamp apparatus as claimed in Claim 7, wherein the means for allowing the bias of the biasing means to be overcome comprises a foot member extending from each clamping member, the foot member being located on either side of the space between the clamping members in which, in use, an item clamped by the clamping members is positioned.
9. A clamp apparatus according to any preceding claim, wherein each foot member projects downwardly from a base of each clamping member, thereby raising the clamping members from a surface on which they are positioned.
10. A clamp apparatus according to Claim 9, wherein the surface of each foot member is adapted to allow each base to rotate about a pivot point provided by each foot.
11. A clamp apparatus according to Claim 10, wherein the surface of each foot member is curved.
12. A clamp apparatus according to any preceding claim, wherein a first end of the spring is permanently secured to a first of said clamping members and is releasably secured at a second end of said spring to the second of said clamping members.
13. A clamp apparatus according to Claim 12, wherein the second end of the spring is releasably secured by way of a frictional force member gripping said spring.
14. A clamp apparatus according to Claim 12, where the frictional force member is a locating screw threaded bolt which passes through a screw threaded hole and secures said spring.
15. A clamp apparatus for holding an article in a generally vertical plane, the apparatus comprising two clamping members having inner portions for clamping about said item, each clamping member having a respective foot for supporting said clamping member, the apparatus further including a biasing means for mechanically securing the two clamping members to one another so that said members can rotationally move relative to one another between a clamping position and a release position, wherein said biasing means is provided as a leaf spring which is of sufficient stiffness to substantially prevent the inner portions from rotating downwardly about the respective foot members thereby biasing the clamping members to a release configuration so that an article can be received in the clamp and wherein when an article is placed on the leaf spring, the biasing effect of the leaf spring is overcome by the weight of the article acting on the leaf spring so causing the inner portions of the two clamping members to rotate downwardly so that the article is clamped in said clamp apparatus.
Description:
A Clamp Apparatus The present invention relates to a clamp apparatus and particularly, but not exclusively, to apparatus for holding an item such as a door.

It is very well known to use a clamp or vice mechanism for temporarily holding an item to be worked upon such as a door or window frame. One particular prior art clamp for holding a door is disclosed in patent document US 5,294, 099.

This prior art clamp comprises two gripping members each having a horizontal base member and an upright clamp member. A pair of resiliently compressible support pads is attached to the underlying surface of outer end portions of the base members and these have the effect of holding the apparatus stationary on a floor surface in a substantially non-slip manner. The support pads also have the effect of elevating the outer end portions of the base members above the floor. A hinge is provided at the inner end portions of the base members for pivotally coupling the hinge members together. The arrangement is such that the upright clamp members are spaced from one another so as to provide a slot in which a door may be received.

In use of the prior art apparatus, the base members at their adjacent inner end portions are able to oppositely pivot upward away from the floor to a higher elevation than the outer end portions of the base members by virtue of the hinge. In pivoting the base members in this way, the slot between the upright clamp members is widened so as to facilitate ready positioning of a door in the apparatus. The base members may also oppositely pivot downward toward the floor and thereby locate at a lower elevation than that of the outer end portions of the base members. This movement results in the upright clamp members moving towards one another and allows a door placed within the aforementioned slot to be gripped by the clamp members. The door may be thereby firmly held by the prior art apparatus.

A problem associated with the above prior art apparatus is that the weight of the door bears upon the hinge and can

result in the upright clamp members gripping the door located therebetween so tightly that the apparatus tends to become jammed and the door difficult to release. The apparatus also tends to locate in a clamping position under the action of gravity and this can make it difficult to position an item between the clamp members.

It is an object of the present invention to provide improved apparatus for gripping an item and particularly an item such as a door.

The present invention provides a clamp apparatus for holding an item in a generally vertical plane, the apparatus comprising two members for clamping about an item; and biasing means for biasing the two clamping members from a clamping position towards a release position wherein the distance between the clamping members is greater in the release position than in the clamping position.

Thus, in use of clamp apparatus according to the present invention, release of an item held between the clamping members is assisted by biasing means which tends to move the clamping members away from the clamping position towards a release position.

Preferably, the biasing means may mechanically secure the two clamping members to one another. The biasing means may mechanically secure the two clamping members to one another so that said members are rotationally movable relative to one another between the clamping position and the release position.

It may also be preferable for the biasing means to be adjustable in such a way as to allow the distance between the clamping members, when said members are in the release position, to be selectively varied. Ideally, the biasing means is telescopically mounted to one of the clamping members. The clamping member to which the biasing means is telescopically mounted may be provided with means for selectively securing the biasing means to the biasing member.

However, during operation of the clamp, the spring is positively clamped against movement in either direction so that the gap between the jaws is maintained even when not in use.

This prevents problems associated with the prior art where there may be slippage of a spring which could result in the

clamps closing, making it difficult to slide material between the gripping members of the clamp apparatus. By having a spring that is clamped, this restricts movement of the gripping members to a pivot action only. Preferably, the spring is permanently fixed in one jaw and clamped to the other, for example, by a thumb wheel.

Furthermore, means are ideally provided for allowing the bias of the biasing means to be overcome when, in use, an item to be clamped is rested on said apparatus between the clamp members. The means for allowing the bias of the biasing means to be overcome may comprise a foot member extending from each clamping member, the foot members being located on either side of the space between the clamping members in which, in use, an item clamped by the clamping members is positioned.

The biasing means may comprise a spring which may be a leaf spring.

An embodiment fo the present invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a schematic side view of apparatus according to the present invention; Figure 2 is a schematic end view of the apparatus of Figure 1; and Figure 3 is a schematic side view of the apparatus of Figure 1 in use clamping a door.

The accompanying drawings show a clamping apparatus 2 which is of a similar design to the aforementioned prior art apparatus of US 5,294, 099 in that two gripping members are provided which each have a base member and upright clamp member with support pads on outer end portions of the base members and hinge means connecting inner end portions of the base members so as to allow a downward and opposite upward relative rotation of said members. More specifically, each gripping member 4, 6 is fabricated from a single sheet of metal and comprises a base member 8,10 from inner end portions 12,14 of which a clamp surface 16,18 upwardly extends. Each gripping member 4,6 also comprises a reinforcing web portion 20,22 which extends from one edge of the associated clamp surface 16,18 to an edge of the associated base member 8,10. The gripping

members 4,6 are thereby stiffened and the clamp surfaces 16, 18 are less likely to bend relative to their respective base members 8,10 during use.

The support pads of the clamping apparatus 2 are provided as metal feet members 24,26 which are located at the outer end portions 28,30 of the base members 8, 10. The feet members 24,26 project downwardly from the lower surface of the base members 8,10 and have the effect of raising the base members 8,10 off the floor on which the apparatus 2 is placed during use. The surface of the feet members 24,26 which, in use, engages the floor is preferably adapted to allow the base members 8,10 to readily rotate. The surface of the feet members 24,26 engaging the floor is therefore ideally curved.

The hinge means of the clamping apparatus 2 is provided as a leaf spring 32 which extends between inner end portions 12,14 of the base members 8,10. In the clamping apparatus 2 shown in the accompanying drawings, the leaf spring 32 is permanently secured to the inner end portion 12 of the first gripping member 4 and releasbly secured to the inner end portion 14 of the second gripping member 6. The leaf spring 32 has sufficient stiffness to substantially prevent the inner end portions 12,14 from rotating downwardly about the feet members 24,26 under the weight of the clamping apparatus 2.

The leaf spring 32 is releasbly secured to the second gripping member 6 in such a way as to allow the size of the slot between the clamp surfaces 16,18 to be varied. In this regard, the leaf spring 32 extends through an aperture (not shown) in the clamp surface 18 of the second gripping member 6 and locates over a boss 34 in which a screw threaded hole 36 is provided (see Figure 2). The leaf spring 32 is itself provided with a plurality of holes (not shown) along its length and any one of these holes may be aligned with the screw threaded hole 36. The width of the slot between the clamp surfaces 16,18 is varied depending upon which hole in the leaf spring 32 is aligned with the screw threaded hole 36. When a spring hole has been selected and aligned with the screw threaded hole 36, the leaf spring 32 may be secured in position by locating a screw threaded bolt 38 through the spring hole and into screw threaded engagement with the screw threaded hole

36. In this way, the width of the slot between the clamp surfaces 16,18 may be varied to best suit the width of the door or other item to be placed therein.

As the spring is of a broad spring plate type, it provides a good support, even for relating soft materials, which assists in preventing damage to an object that is being clamped.

Other mechanisms for allowing a telescopic adjustment of the leaf spring relative to the gripping members 4, 6 will be apparent to the skilled reader. For example, rather than providing the spring with a plurality of holes, a mechanism may be provided by which the portion of leaf spring 32 extending into the second gripping member 6 is clamped and held by friction forces. In this way, any slot width (rather than predetermined slot widths) may be selected within a given range.

The clamp surfaces 16,18 are each provided with a resiliently compressible pad which serves to protect the item which is clamped in use. The pads 40 may be manufactured from a rubber material.

As shown in Figure 1, the pads 40 have cutaway portions at their upper and lower ends. the cutaway at the lower end enables there to be an upward flexing of spring 32.

In use of the clamping apparatus 2, the gap (ie the aforementioned slot width) between the clamp surfaces 16,18 is adjusted by telescopically lengthening or shortening the leaf spring 32 extending between the gripping members 4,6 so as to allow a door 42 (or other item to be gripped) to be readily located between the clamp surfaces 16,18. In order to ensure the apparatus 2 firmly grips the door 42, the distance between the pads 40 of the gripping members 4,6 should be only marginally greater than the thickness 44 of the door 42 (see Figure 3). Once the door 42 has been placed between the pads 40, the weight of the door 42 is allowed to rest on the leaf spring 32. In so doing, the inner end portions 12,14 of the base members 8,10 move downwardly and the clamp surfaces 16,18 move towards one another and grip about the door 42. As will be seen from Figure 3 it is the pads 40 on the clamp surfaces 16,18 which physically engage

the door 42 and thereby protect the door 42 from being damaged.

The pads 40 resiliently deform and ensure a high friction grip on the door 42. With the door securely gripped between the clamp surfaces, the clamping apparatus 2 provides the door 42 with sufficient lateral support for the door 42 to remain in an upright standing position. The door 42 may be then worked upon in a convenient fashion.

It will be understood that the downward rotating of the gripping members 4,6 is achieved by the weight of the door 42 overcoming the bias of the leaf spring 32 which tends to press the gripping members 4,6 towards the release position shown in Figure 1. This spring bias has the effect of allowing the door 42 (or any other item clamped) between the gripping members 4,6) to be conveniently released by application of an upward force so as to lift the weight of the door 42 from the leaf spring 32. With the weight of the door 42 lifted from the leaf spring 32, the leaf spring 32 tends to move the apparatus 2 to the release configuration of Figure 1. The door 42 may then be removed from the apparatus 2.

It will also be appreciated that the provision of the spring 32 ensures that the clamping apparatus 2 rests in the release configuration and is accordingly always ready to receive an item to be clamped.

The present invention is not limited to the specific embodiment described above. Alternative arrangements and suitable materials will be apparent to a reader skilled in the art. For example, the leaf spring may be permanently secured or, alternatively, releasably secured, to both gripping members 4,6. Furthermore, alternative means for biasing the gripping members 4,6 into the release configuration may be provided.

In this regard, the gripping members 4,6 may be pivotally connected to one another by means of conventional hinge and biased into the release configuration by means of a helical compression spring extending downwardly into engagement with the floor from each inner end portion 12,14.