GB2325695A - Fastening device with transversely displaceable jaws - Google Patents

Abstract

A fastening device comprises a pair of transversely displaceable jaw members 24, 26 at least one of which is biased toward the other, a longitudinally displaceable button 14 and a linking mechanism between the button and one or both jaw members adapted to convert longitudinal motion of the button to transverse motion of at least one jaw member. The linking mechanism is preferably at least one arm 20, 22 pivotably connected at one end to the button and at another to a jaw member. Preferably, the or each jaw is constrained to move only in a transverse direction. Both jaws may be biased toward each other, or one jaw may be fixed and the other biased toward the fixed jaw. Electromagnetic assistance can be provided, in the form of an electromagnet located within one or both jaws. The battery can be stored within the button. It is preferable to withdraw power from the electromagnet when to jaws are fully closed, to preserve battery life.

Description

FASTENING DEVICE The present invention relates to a fastening device.

Fastening devices are known as such, but those which provide an adequate fastening force usualiy suffer from excessive stiffness in applying and removing a device. Conversely, those which are easy to attach normally apply an inadequate fastening force. The present invention seeks to overcome this balance.

The present invention therefore provides a fastening device comprising a pair of transversely displaceable jaw members at least one of which is biased toward the other, a longitudinally displaceable button, and a linking mechanism between the button and one or both jaw members adapted to convert longitudinal motion of the button to transverse motion from at least one jaw member.

The linking mechanism is preferably at least one arm rotatably connected at one end to the button and at another end to a jaw member, at a divergent angle with respect to the longitudinal direction. This provides a particularly simple mechanism which is able to provide both the necessary action.

Preferably, the or each jaw is constrained to move only in a transverse direction.

It is naturally preferred if both jaws are biased toward each other, but the invention is capable of application in circumstances where one jaw is fixed and the other is biased toward the fixed jaw.

The jaws of the device can also be biased together by an electromagnet, preferably situated within one or both jaws. This can be activated by a suitable arrangement of contacts associated with the button, preferably such that the electromagnet is activated when the device is not fully closed.

Embodiments of the invention will now be described by way of example, with reference to the accompanying Figures, in which: Figure 1 is a vertical cross-section of the first embodiment of the present invention, with the button in the depressed position and the jaws in the open position; Figure 2 is a similar cross-section to Figure 1, but with the button in the released position and the jaws in the closed position; Figure 3 is a cross-section on Ill-Ill of Figure 1; Figures 4 and 5 are perspective views of a second embodiment of the invention; and Figure 6 is a sectional view of a third embodiment.

Figures 1 to 3 show a first embodiment of the fastening device according to the present invention. A body 10 has a central bore 12 running internally along its longitudinal axis. The bore 1 2 is of varying width as will be apparent from the subsequent description. A plunger 14 sits within the bore 12 at one end thereof, projecting out of the body 10. The plunger 14 is able to move longitudinally within the bbre. At the end of the plunger 14 within the body 10, a recess 1 6 accommodates a hinge roller 1 8. A pair of arms 20, 22 are rotatably connected to the hinge 1 8 and can therefore rotate thereabout.

At the other end of the bore 12, a pair of jaws 24, 26 are provided.

These are able to move transversely across the bore, in a direction substantially perpendicular to the plane of the hinge 18. They are constrained against longitudinal movement by engagement of a lug 28 behind ridges 30, 32 formed in the side of the bore 12. Each jaw 24, 26 is biased toward the other by a compression spring 34, 36.

The free ends of the arms 20, 22 are connected to a face of each jaw 24, 26 respectively. This means that as the plunger is depressed into the bore 12, the arms 20, 22 are forced to swing outward, opening the jaws 24, 26 to the position shown in Figure 1. When the pressure on the plunger 14 is released, the compression springs 34, 36 force the jaws 24, 26 to close, in turn causing the plunger 14 to rise.

Figures 1 and 2 also show a pair of springs 40, 42 which lie in channels 44, 46 either side of the plunger 14. These exert an upward force on the plunger 14 via lugs 48, 50 on either side of the plunger 14 which project into the channels 44, 46. Thus, when the device grips an object within the jaws 24, 26, the plunger 14 is propelled to its upper position when released. This prevents the plunger 14 from rattling and gives a neater appearance.

Figures 4 and 5 show a second embodiment of the present invention, in which immaterial external dimensions differ slightly. Also shown in the second embodiment is a recess 50 formed on the internal faces of the jaws 24, 26 to provide a better grip.

The internal recess 50 could of course be replaced by a rough surface, or a saw-tooth surface, or any similar gripping surface.

Figure 5 also includes arrow A, showing the direction of force applied to the plunger 14, resulting in opening of the jaws 24, 26 in the direction of arrow B.

Figure 6 shows a third embodiment including electromagnetic closing assistance. It is generally similar to the embodiments of Figures 1 and 2, but includes a battery 51 instead of or within the button 14. This can suitably be a rechargeable battery of the type commonly used in cordless drills, screwdrivers etc. A contact 52 within the device makes two-pole electrical contact with the battery 51 when the battery/button is in any position other than fully closed. The contact 52 leads to a cable 54 which takes that electrical power to a contact 56. This, again, is adapted to make electrical contact with the jaw 26 when the latter is in any position other than fully closed. The jaw 26 contains an electromagnet 58, whereas the opposing jaw 24 is made of a ferro-magnetic material. Thus, when the electromagnet 58 is activated, the two jaws 24, 26 are drawn firmly toward each other.

However, when both jaws are fully closed and in contact, one or both of the contacts 52, 56 is broken and no current flows. Thus, battery life is conserved when the device is not in use. However, as soon as the device is opened, as it will need to be in order to retain a device between the jaws 24, 26, electrical contact is made and the electromagnet is activated.

It will of course be appreciated by those skilled in the art that the above described embodiments serve simply to exemplify the present invention, which is naturally not limited thereby.

Claims (9)

1. A fastening device comprising a pair of transversely displaceable jaw members at least one of which is biased toward the other, a longitudinally displaceable button, and a linking mechanism between the button and one or both jaw members adapted to convert longitudinal motion of the button to transverse motion from at least one jaw member.

2. A fastening device according to claim 1 wherein the linking mechanism comprises at least one arm rotatably connected at one end to the button and at another end to a jaw member, at a divergent angle with respect to the longitudinal direction.

3. A fastening device according to claim 1 or claim 2 wherein the or each jaw is constrained to move only in a transverse direction.

4. A fastening device according to any preceding claim wherein both jaws are biased toward each other.

5. A fastening device according to any one of claims 1 to 3 wherein one jaw is fixed and the other is biased toward the fixed jaw.

6. A fastening device according to any preceding claim wherein at least one jaw includes an electromagnet thereby to attract the other jaw.

7. A fastening device according to claim 6 wherein the button includes a battery for powering the electromagnet.

8. A fastening device according to claim 6 or claim 7 wherein electrical power is withdrawn from the electromagnet when the jaws are fully closed.

9. A fastening device substantially as herein described with reference to and/or as illustrated in the accompanying drawings.