GB2094387A

GB2094387A - Releasable securing device

Info

Publication number: GB2094387A
Application number: GB8107568A
Authority: GB
Original assignee: York Forge & Welding Co Ltd
Current assignee: York Forge & Welding Co Ltd
Priority date: 1981-03-10
Filing date: 1981-03-10
Publication date: 1982-09-15
Also published as: GB2094387B

Abstract

A device for securing parts together comprises a pin (10) with axially spaced stops (11 and 13). One of the stops (11) constitutes a latch and is made from a length of resilient wire. At one end the wire is shaped either as a coil (17) and mounted on the adjacent end portion (15) of the pin, or as a mounting pin (20), which enters an axial hole in the pin. The other end (19) of the wire projects into a transverse hole (16) in the pin. The intermediate part (18) of the wire is normally inclined to the axis of the pin. When the pin is pushed latch-first into aligned holes in the parts to be secured together, the intermediate part of the latch is automatically urged towards the pin. When the latch emerges from the holes it springs back to its normal position, and the transverse end (19) prevents withdrawal of the pin. The fixed stop (13) may be replaced by a second latch. <IMAGE>

Description

SPECIFICATION Releasable securing device This invention relates to a releasable securing device, and in particular to a device of the kind comprising a pin which can be inserted through aligned holes in parts to be secured together and which is provided with releasable retaining means enabling the pin to be secured against withdrawal but capable of being released so as to enable the pin to be withdrawn when necessary.

It is obviously desirable for the device to be constructed and arranged in such a manner that in normal use its component parts do not have to be separated from one another; further it is desirable that the component parts should be either inseparable or capable of separation only when deliberate steps to this end are taken by the user.

A device of either of these kinds has the advantage that at least in normal use there are no separate component parts of the device which might be inadvertently lost or mislaid or which might be dropped and become dirty. The present invention aims to provide a device such that those problems are avoided.

According to the present invention there is provided a releasable securing device comprising a pin provided at axially spaced positions with a pair of stops, at least one of the stops comprising a latch movable between a securing position in which it projects laterally from the pin and a release position in which it does not project laterally from the pin or projects to a lesser extent than when it is in its securing position, spring means urging the latch towards its securing position, the arrangement being such that the pin, with its latch in the release position, can be inserted through aligned holes in articles to be secured together, and that the latch can then assume its securing position, whereupon the stops prevent withdrawal of the pin until the latch, or at least one of the latches where more than one is provided, is moved to its release position.

The latch or at least one of the latches preferably has an inclined face so arranged that if the pin is inserted into a hole latch first the face engages the edge of the hole, and as the pin is pushed further into the hole the latch is automatically moved to its release position against the action of the spring means.

The latch or each latch together with its associated spring is preferably formed as a unitary whole, preferably of resilient metal wire.

One of the stops is preferably immovable and is formed integrally with the pin.

Securing devices embodying the invention are illustrated, by way of example, in the accompanying drawings, in which: Figure 1 is a side view of a securing device embodying the present invention, and Figure 2 is a side view of a slightly different securing device embodying the present invention.

The securing device shown in Figure 1 comprises a body part 10, made from steel rod of circular cross-section, and a spring part 11. The body part comprises a main portion 12 which constitutes a pin. At one end of the pin is a portion 13 of larger diameter than the pin and which constitutes a fixed stop. This fixed stop is of the same diameter as the rod from which the body is formed and is knurled to afford the user a good grip. At the other end of the pin 1 2 the body is formed with a retaining portion 14 of a diameter smaller than that of the pin 1 3. The body then terminates in a mounting portion 1 5 of a diameter smaller than that of the retaining portion 14. A diametral hole 1 6 is formed through the retaining portion 14, at a location near to the adjacent end of the pin 13.

The spring part 11 is made from a length of resilient metal wire of which one end portion is shaped to form a mounting coil 1 7 which fits onto the mounting portion 15 of the body. The axial length of the coil is somewhat less than that of the mounting portion, and the arrangement is such that the free end part of the mounting portion projects beyond the coil. The remainder of the spring part constitutes a latch, and comprises an inclined portion 18 and an abutment portion 19.

The spring part is illustrated in its securing position, in which it is unstressed. The inclined portion 18 is inclined to the axis of the body part 10; that end of the inclined portion connected to the mounting coil 1 7 is at a radial distance from the axis of the body part less than the radius of the pin 12, while the other end of the inclined portion, which is connected to the abutment portion 19, is at a radial distance from the axis of the body part greater than the radius of the pin. The abutment portion 1 9 extends radialiy inwards from the latter end of the inclined portion and enters the hole 1 6.

The fact that the abutment portion enters the hole 16 prevents mounting coil 1 7 slipping off the end of the mounting portion 1 5. During assembly of the device, however, the inclined portion is flexed resiliently outwards sufficiently far to enable the mounting coil to be fitted onto the mounting portion, the inclined portion then being released so as to allow the abutment portion to enter the hole.

The device can be used in releasably securing together parts with aligned holes, into which the pin is inserted. In a typical application the device is used for releasably securing a mixing drum of a concrete mixer to a power driven shaft thereof. A tubular collar projects axially from the back of the drum and embraces the end portion of the shaft.

Diametral holes just large enough to accept the pin 12 are formed in the collar and the shaft and can readily be brought into mutual alignment. A securing device of the kind illustrated in Figure 1 is then inserted into the aligned holes to secure the drum to the shaft. During the initial stages of insertion the outwardly directed face of the inclined portion 18 engages the edge of the hole in the collar, and further insertion causes the inclined portion to be flexed to a release position in which no part thereof is at a distance from the axis of the body portion 1 0 substantially greater than the radius of the pin 12. The diameter of the diametral hole 16 is large enough to allow the abutment portion 1 9 to pass freely into it as the inclined portion moves to the release position.The outside diameter of the collar is equal to the length of the pin 1 2, so that when the pin has been fully inserted the fixed stop 1 3 abuts the collar adjacent to one end of the diametral hole in the collar, while the abutment portion 1 9 of the spring part 11 abuts or lies adjacent to the collar adjacent to the other end of that diametral hole, the spring part having returned to its securing position on emerging from the hole.

When it is desired to remove the device, the user presses the inclined portion 1 8 of the spring part towards the axis of the body part until it assumes its release position, and pushes or pulls the pin from the.aligned holes. If it proves difficult to start the axial movement of the device manually, the end of the body part may be tapped with a hammer to start it moving. It will be noted that if this is done the hammer strikes the end of the mounting portion 15 of the body and does not strike the spring part 11.

The device shown in Figure 2 is largely similar to that shown in Figure 1, and similar parts are given the same reference numerals. In place of the mounting coil 17, however, the spring part is formed with an axially directed mounting pin 20 which enters an axial hole in the mounting portion 15 and which may extend as far as desired into the retaining portion 14. The device can be used in a manner similar to the device shown in Figure 1.

It will be understood, however, that it is not suitable for it to be struck with a hammer as the hammer would strike the spring part.

The securing devices described above are simple and inexpensive to manufacture and assemble, and are effective in use. The body parts can be made largely on an automatic lathe, and should the spring parts become damaged they can readily be replaced. Numerous modifications are possible within the scope of the present invention.

For example, as indicated above, it would be possible to provide a device with a latch at each end. In that case the device would preferably be symmetrical about a plane passing through the centre of the pin, normal to the axis of the pin.

Claims

1. A releasable securing device comprising a pin provided at axially spaced positions with a pair of stops, at least one of the stops comprising a latch, movable between a securing position in which it projects laterally from the pin and a release position in which it does not project laterally from the pin or projects to a lesser extent than when it is in its securing position, and spring means urging the latch towards its securing position, the arrangement being such that the pin, with its latch in the release position, can be inserted through aligned holes in articles to be secured together, and that the latch can then assume its securing position, whereupon the stops prevent withdrawal of the pin until the latch, or at least one of the latches where more than one is provided, is moved to its release position.

2. A releasable securing device according to claim 1 in which the latch or at least one of the latches has an inclined face so arranged that if the pin is inserted into a hole latch first that inclined face engages the edge of the hole, and as the pin is pushed further into the hole the latch is automatically moved to its release position against the action of the spring means.

3. A releasable securing device according to either of claims 1 and 2 in which the latch or each latch together with its associated spring means is formed as a unitary whole.

4. A releasable securing device according to claim 3 in which the latch or each latch together with its associated spring means is formed of resilient wire.

5. A releasable securing device according to claim 4 in which the latch or each latch, together with its associated spring means, comprises a length of resilient wire so shaped as to afford mounting means, abutment means and an inclined portion between the mounting means and the abutment means, the mounting means being mounted on or in an end portion of the pin, the abutment means entering a transverse hole in the pin, and the inclined portion extending lengthwise of the pin between the mounting means and the abutment means, the abutment means and the inclined portion together constituting the latch, and the arrangement being such that when the pin is inserted latch-first into aligned holes in parts to be secured together, engagement with the inclined portion, as the pin is pushed further into the holes, causes the latch to be moved automatically to its release position, while the abutment means moves further into the transverse hole, and when the latch emerges from the aligned holes the latch returns automatically to its securing position.

6. A releasable securing device according to claim 5 in which the mounting means comprises a coil which fits onto the end portion of the pin.

7. A releasable securing device according to claim 6 in which the pin projects beyond both ends of the coil.

8. A releasable securing device according to claim 5 in which the mounting means comprises a mounting pin which enters an axial hole in the end portion of the pin.

9. A releasable securing device according to any one of the preceding claims in which one of the stops is immovable and is formed integrally with the pin.

10. A releasable securing device substantially as hereinbefore described with reference to Figure 1 of the accompanying drawings.

11. A releasable securing device substantially as hereinbefore described with reference to Figure 2 of the accompanying drawings.