GB2129043A

GB2129043A - Clamping assembly

Info

Publication number: GB2129043A
Application number: GB08230691A
Authority: GB
Inventors: David Partridge
Original assignee: Starpoint Electrics Ltd
Current assignee: Starpoint Electrics Ltd
Priority date: 1982-10-27
Filing date: 1982-10-27
Publication date: 1984-05-10

Abstract

A ring 2 is locked to a tube 1 of slightly smaller diameter than the internal diameter of the ring by means of a generally U-shaped component 8 having two limbs 9, 10 capable of resilient displacement in relation to one another. The limb 9 co-operates with an axially inclined surface 5, located in a recess 4 in the interior of the ring, so that axial movement of the component 8 in relation to the ring 2 produces a wedging action forcing the limb 9 against the surface of the tube to establish a frictional lock. The other limb 10 engages the outer surface of the ring 2 and is formed with a shoulder 16 co-operating with a corresponding shoulder 17 on the other surface of the ring to hold the component in the locking position. <IMAGE>

Description

SPECIFICATION Clamping assembly Many arrangements are available for clamping assemblies to tubes or pipes in heavy duty conditions. It sometimes happens, however, that a comparativeiy light assembly or component needs to be clamped to a relatively thin tube, for example of plastics material, and moreover may need to be adjustable along the pipe or tube. For example, in coin handling equipment it may be necessary to detect the presence of coins in a tubular magazine.

A common method of obtaining this result is to use a transparent tube with a light source on one side and a detector on the other side, so that a signal is produced when a coin moves through the beam of light between the source and the detector, e.g. if an individual coin falls through the beam or the top of a stack of coins in the tube moves upwardly or downwardly through the beam. As a matter of convenience the light source and the detector and the associated circuitry may be mounted in a common ring which needs to be clamped to the tube and also needs to be adjustable so as to adjust the level at which the coins are detected The heavy duty arrangements used in normal engineering practice are quite unsuitable for a purpose such as this.

The present invention is based on the principle of a ring which is a relatively loose fit on the pipe or tube in question and the use of a component which is clipped to the ring and has a portion located between the surface of the ring and the surface of the tube which has a wedging action locking the ring to the tube when the component is clipped in position.Thus, according to the invention, the component is generally U-shaped so as to have two limbs capable of resilient displacement in relation to one another, one of which limbs co-operates with an axially inclined surface located in a recess in the interior of the ring so as to face the surface of the tube, so that axial movement of the component in relation to the ring produces a wedging action forcing the limb against the surface of the tube to establish a frictional lock, the other limb engaging the outer surface of the ring and being formed with a shoulder co-operating with a corresponding shoulder on the outer surface of the ring so that when the component is moved axially to the locking position engagement between the two shoulders prevents return movement and clips the component in its locking position.Consequently, in order to clamp the ring in position it is first slid along the tube and the U-shaped component is then moved into its locking position in which it is automatically clipped by the engagement of the two shoulders, simultaneously introducing the wedging action which locks the ring in the selected position. The wedging action tends to displace the ring laterally in relation to the tube to a small extent and if it is important that the ring should be fairly accurately centered, the ring may be locked from opposite sides by two similar wedging components.

The shoulder on the outer surface of the ring is preferably formed by one side of a projecting ridge extending circumferentially of the ring and the outer limb of the wedging component is formed with a projecting portion which, when the shoulders are in engagement, bears against the other side of the ridge. In other words, the ridge is located between the shoulder and the projecting portion which may conveniently be relatively thin and flexible and this assists in holding the component as a whole in position.

It will be appreciated that the clamping arrangement is extremely simple, both in construction and use, in that the ring can be moved to any desired position on the tube and when that position has been reached, it is then merely a question of moving one or more wedging components into their locking positions where they are automatically clipped by the arrangement already described. When the ring needs to be unlocked, it is merely a question of unclipping the wedge component by disengaging the co-operating shoulders, and for this purpose the component may be formed with a projecting part with facilitates flexing in order to move the shoulder on the component away from that on the ring.

An example of an arrangement in accordance with the invention will now be described in more detail, with reference to the accompanying drawings, in which: Figure 1 is a longitudinal sectional view showing a ring in position on a tube with a wedging component in an unlocked position; and Figure 2 is a view similar to Figure 1 but showing the wedging component in the locked position clamping the ring against the tube.

In both views the tube is shown as 1 and the ring as 2. Although no details are shown, the tube 1 may be of transparent plastics material serving as a coin magazine and the ring 2 may support a light source and detector on opposite sides of the tube 1 with connecting circuitry passing through the hollow interior of the ring at 3. On the right hand side as seen in the drawings, the ring 2 is formed with a recess indicated generally as 4 which has a surface 5 facing the surface of the tube 1 and inclined to the axis at a small angle in the region of 10 to 1 5 degrees. The recess 4 is open at the top for the insertion of a wedging component 8 which is of inverted U-shape, and is formed as a moulding of resilient plastics material so that its two limbs 9 and 10 are capable of resilient displacement in relation to one another.

The limb 9 fits into the recess 4 and has a lower portion 12, the right hand side of which co-operates with the inclined surface 5 on the ring and the left hand side of which, braced by a strut 13, engages the surface of the tube 1 at 14. The outer limb of the component 8 engages the outer surface 1 5 of the ring 2 outside the recess 4 and is formed with an upwardly facing square shoulder 1 6 which co-operates with a downwardly facing shoulder 1 7 defined by the lower surface of a circumferentially extending ridge 18 on the surface 1 5 of the ring.

In the position shown in Figure 1, the inner limb 9 is clear of the inclined surface 5, the portion 14 rests lightly against the surface of the tube 1 and the component is supported by the upper surface of the ridge 18. When downward pressure is exerted on the component 8, the outer limb 10 is displaced slightly outwardly so as to ride over the ridge 18 and the inner limb 9 comes into engagement with the inclined surface 5. As the downward movement is continued the reaction between the limb 9 and the inclined surface 5 produces a wedging action which forces the portion 14 into firm engagement with the surface of the tube 1, the pressure between the two increasing with the extent of the downward movement.As explained originally, the arrangement is intended only for light duties so that no excessive pressure need be exerted and the proportions are designed so that when the shoulder 1 6 passes over the ridge 1 8 and comes into engagement with the shoulder 17, adequate locking pressure is exerted. This position is illustrated in Figure 2, in which it will be seen that the engagement between the shoulders 1 6 and 1 7 resists the upward force resulting from the reaction between the limb 9 and the inclined surface 5 and this effectively clips the component in position.At this stage, a relatively thin and flexible projecting portion 20 on the inner side of the limb 10, which is situated a short distance above the shoulder 16, engages the upper surface of the ridge 1 8 which is then locked between the shoulder 1 6 and the projection 20 so that the component 8 is positively located.

The projection 20 is located in a space 21 defined by an outwardly curved portion 22 of the limb 10, this portion contributing to the overall flexibility of the limb to assist in the unlocking step. For unlocking purposes, the limb 10 has a downwardly extending projection or tab 24 which can be engaged by the finger and moved outwardly in the direction of the arrow in Figure 2.

This causes flexing of the portion 22 sufficient to disengage the shoulders 1 6 and 1 7 so that as a result of the reaction between the inner limb 9 and the inclined surface 5, assisted if necessary by slight upward finger pressure on the tab 24, the component is moved back to the unlocked position of Figure 1 and the ring 2 can then be slid quite freely again from the tube 1. In this way the ring 2 can be adjusted as required quite freely on the tube 1, and can then be clamped in any required position as a result of straight forward pressure on the component 8, being subsequently released in the manner just described.

The wedging action between the ring 2 and the tube 1 caused by the reaction between the inner limb 9 and the inclined surface 5 tends to displace the ring 2 slightly to the right as seen in the drawings, and if it is important that the ring should be centralised more accurately, more than one clamping arrangement may be fitted, e.g. two at diametrically opposite points or three at equally angular intervals.

Claims

1. The combination of a ring and a component for locking the ring to a pipe or tube of slightly smaller diameter than the internal diameter of the ring, the component being generally U-shaped so as to have two limbs capable of resilient displacement in relation to one another, one of which limbs co-operates with an axially inclined surface located in a recess in the interior of the ring so as to face the surface of the tube when the ring is in position on the tube, so that axial movement of the component in relation to the ring produces a wedging action forcing the limb against the surface of the tube to establish a frictional lock , the other limb engaging the outer surface of the ring and being formed with a shoulder co-operating with a corresponding shoulder on the outer surface of the ring so that when the component is moved axially in relation to the ring, to the locking position, engagement between the two shoulders prevents return movement and clips the component in its locking position.

2. A combination according to claim 1, in which the shoulder on the outer surface of the ring is formed by one side of a projecting ridge extending circumferentially of the ring and the outer limb of the wedging component is formed with a projecting portion which, when the shoulders are in engagement, bears against the other side of the ridge.

3. The combination of a ring and a component for locking the ring to a pipe or tube of slightly smaller diameter than the internal diameter of the ring, substantially as described and as illustrated with reference to the accompanying drawings.