GB2240058A

GB2240058A - Device for applying torque

Info

Publication number: GB2240058A
Application number: GB9007733A
Authority: GB
Inventors: Adrian Thomas Cole
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-01-17
Filing date: 1990-04-05
Publication date: 1991-07-24
Also published as: GB9007733D0; GB9000991D0

Abstract

A device for applying torque to angular objects such as nuts and bolts comprises a rigid case 1 provided with a plurality of resiliently biased hexagonal elements 4. In use the device is applied to an object and some elements are displaced thereby. The elements 4 thus conform to the shape of the object. Torque applied to the case 1 is transferred to the elements 4 and hence the object. <IMAGE>

Description

METHOD OFi AND DEVICE FOR, APPLYING TORQUE This invention relates to methods of, and devices for, applying torque. More especially but not exclusively the invention relates to wrenches for fastening and unfastening screw fasteners.

Screw fasteners especially nuts and bolts are very useful but the large number of head sizes result in a large number of spanners being required. Alternatively incorrect size spanners and adjustable spanners may be used but they can slip on the flats of the head resulting in damage to the operator and the fastener.

The invention seeks to provide a device for applying torque to objects of differing sizes.

According to the invention there is provided a device for applying torque to an angular object, the device comprising a rigid case containing a plurality of resiliently mounted elements, the elements being arranged with substantially parallel longitudinal axes, the elements being biasable away from their rest position the arrangement being such that when the device is applied to the angular object the elements conform to the object thereby allowing torque to be applied to the object.

An embodiment of the invention will be illustrated by reference to the accompanying drawings of which Figure 1 is a partially cut away side elevation and Figure 2 is a top plan The device comprises a rigid case 1 preferably of a steel. An end of the case 1 is provided with a drive spigot or recess 2 for drive means. A handle (not shown) may be provided in place of the spigot 2.

The opposing face of case 1 is provided with a cavity 3. Preferably cavity 3 is hexagonal. Other shapes may be used but the cavity is preferably angular so that the case assists elements 4 in resisting torsional forces. The interior of the cavity 3 may be moulded to fit exactly the extreme outer pattern created by the plurality of elements 4.

Case 1 is provided with a plurality of elements 4 which substantially fill cavity 3. Preferably a large number of such elements are provided. If few are provided they will not conform to the object as well as if a large number are provided. A very large number of elements may result in a device which is expensive to manufacture. Those skilled will readily be able to determine the optimum number and hence size of elements for a particular application.

Preferably the elements are all regular hexagonal ,prisms because this will result in a good fit when used in conjunction with common hexagon headed fasteners.

Other shapes such as square prisms may be used.

Cylindrical elements may be advantageous because assembly does not require relative orientation of adjacent elements.

The elements 4 are resiliently mounted in the case 1. Preferred resilient mounting means are helical compression spring 6. An end of spring 6 can be secured for example by adhesive or as a tight fit to an end of element 4 which may be cylindrical, a reduced diameter cylindrical projection 5 inside the helical spring 6 from element 4 serves as a guide to prevent the spring buckling during compression. The other end of spring 6 is secured to the base 7 of cavity 3. A preferred method of construction includes the steps of providing a case with a cavity and applying a layer of adhesive such as an epoxy resin to the base of the cavity. Resilient biasing means such as springs for securing to the element are then mounted in the adhesive. When the adhesive has set or cured the springs will be secured to the cavity base.

The elements can be mounted on the biasing means before, at the same time as, or after mounting in the cavity.

In use the elements are applied to the object to which torque is to be applied. Those elements which contact the object will be biased away from their rest positions while the others will retain their rest position. The elements thereby at least partially envelope the object. The small size of the elements relative to the object ensure that they conform closely to object. Torque can then be applied to the case. The torque is transmitted from the case to elements adjacent the case wall, hence to elements adjacent the object and finally to the object itself. Relative rotation of the object and device is prevented as the elements can not slide past the angular corners of the objects.

It will be appreciated that the biasing means should allow sufficient movement for the elements to envelope sufficient of the object as to allow torque to be applied. those skilled will be able to determine suitable amounts of movement and will bear in mind that nonangular bolts often protrude from nuts increasing the amount of movement necessary.

Although the invention has been illustrated by reference to applying torque to nuts and bolts those skilled will appreciate that the invention has application in other fields.

Claims

1. A device for applying torque to an angular object, the device comprising a rigid case containing a plurality of resiliently mounted elements, the elements being arranged with substantially parallel longitudinal axes, the elements being biasable away from their rest position the arrangement being such that when the device is applied to the angular object the elements conform to the object thereby allowing torque to be applied to the object.

2. A device as claimed in claim 1 wherein the elements are prisms

3. A device as claimed in claim 2 wherein the prisms are hexagonal prisms.

4. A device as claimed in any one of the preceding claims wherein the resilient mountings comprise helical springs.

5. A device as claimed in claim 4 wherein an end of an element having a reduced diameter is located within a helical spring the arrangement being such that the bulkling of the spring is substantially prevented.

6. A device as claimed in any one of the preceding claims wherein the case and elements comprise steel.

7. A device for applying torque substantially as described herein by reference to the figures.

8. A method of applying torque to an angular object comprising the steps of: i applying a device as claimed in any one of the preceding claims to the object; and ii applying a torsional force to the device substantially perpendicular to the longitudinal axes.