EP0215160B1

EP0215160B1 - A hand-grenade pin

Info

Publication number: EP0215160B1
Application number: EP19850305084
Authority: EP
Inventors: Reima T. Kaiponen; Heikki Liimatainen
Original assignee: Kemira Oyj
Current assignee: Kemira Oyj
Priority date: 1985-07-17
Filing date: 1985-07-17
Publication date: 1988-10-12
Also published as: EP0215160A1; DE3565599D1

Description

The present invention relates to a hand-grenade pin.
More particularly this invention relates to a hand-grenade pin comprising an arm part for fitting through openings in the handle and in the body of a hand-grenade, a pulling part associated with one end of the arm part for use in withdrawing the arm part, and a locking part for use in preventing inadvertent withdrawal of the arm part.
In the prior art there was provided such a hand-grenade pin wherein the arm part was formed by a cotter pin. At the end of the cotter pin remote from the pulling part (after insertion of the pin in the hand-grenade), the ends of the two branches of the cotter pin, in use, are bent away from each other in order to lock the cotter pin in place. With this prior art hand-grenade cotter pin, the pulling force required for withdrawing the pin depends on the amount of flare of the branch ends of the cotter pin, and this is not constant. Thus, at times, the withdrawing of the pin can be really difficult, whereas, at other times, there is the danger of the pin being withdrawn inadvertently. In addition, the pulling ring at one end may be caught by something adjacent the grenade, and thereby the pin may be inadvertently withdrawn. In addition, if the cotter pin has already been withdrawn for the purpose of throwing the hand grenade, and the throwing need not be done, it is then desirable to re- secure the grenade it is impossible to re-insert . the cotter pin through the two-dimensionally precise openings spaced at a distance from each other, owing to the nature of the cotter pin, due to the flare of the branch ends of the pin.
Thus, the present invention seeks to provide a hand-grenade pin having the characteristics that (a) the force required for withdrawing the cotter pin is constant and (b) that inadvertent withdrawing of the cotter pin, especially during transportation, is eliminated.
Applicants have become aware, from the European Search Report, of FR-A-593 569 and FR-A-2 142 633.
In FR-A-593 569 there is shown a hand-grenade pin comprising in accordance with the preamble of claim 1, an arm part for fitting through openings in the handle and in the body of a hand-grenade, a pulling part associated with one end of the arm part for use in withdrawing the arm part, and a locking part for use in preventing inadvertent withdrawal of the arm part, said locking part having a free end for securing the arm part, said pulling part comprising a pulling ring adapted to be positioned relative to said arm part so as to engage with said pin in order to secure the hand-grenade for the duration of its transportation.
However, this pin once released is not readily re-secured. The locking part of the pin extends orthogonally to the arm part and is retained by a lip formed on a band around the grenade cap. This lip, which is formed during the assembly of the grenade, will be destroyed so far as concerns its securing function, once the pin is partially pulled out. There are occasions when the pin is to be replaced and this construction would not allow the pin to be fully re-secured. Furthermore, although the pull-ring is illustrated as being engageable with the free end of the pin (i.e. the arm part) it is not readily apparent how this would be achieved. Certainly, it would appear to be difficult in practice to position the ring behind the free and pointed end of the pin (arm part). Again, the force required for withdrawing the pin (arm part) will be variable owing to the configuration and strength (resistance) of the lip on the band which holds the locking part. It will be appreciated that the extent to which this lip formation encloses the locking part of the pin may vary. With that variation so the force required to remove the pin will vary.
The present invention further seeks to provide a hand-grenade pin having the above characteristics (a) and (b) and also positively releasable, but also replaceable, means for securing the pin.
Accordingly, the present invention is characterised in that said locking part comprises a hook-like part having said free end which engages said arm part, said locking part, in use, extending about the handle of the hand-grenade when said arm part is secured, means for displacing said free end of said hook-like part so as to release said arm part for the withdrawal thereof, said pulling ring being engageable with a protrusion on said hook-like part for securing the hand-grenade, and wherein said pulling ring is of such size and shape that, when arranged to extend over said hand-grenade handle, it can be snapped over the said protrusion for securing the hand-grenade for the duration of transportation.
By comparison with FR-A-593 569 the hand-grenade pin above defined has a completely different and advantageous arrangement for securing the pin. The pin has a locking part which has a hook-like part. It is with this hook-like part that the pull-ring engages. Thus the pin is secured by engagement of its own parts. Thus, the stated objective of achieving a constant force for withdrawing the pin is readily achieved. The variable force caused by the degree of flare on the prior art cotter pin or the degree to which the lip (of FR-A-593 569) encloses the pin, simply does not arise. Furthermore in the present arrangement the securing part, in use, also extends about the handle of the hand-grenade which again distinguishes in an advantageous manner from the prior art as exemplified by FR-A-2 142 633. It will also be appreciated that, from a practical standpoint, it is a far preferable operation to place the ring over the hook-like part (defined herein) rather than manipulate the ring over the end of the arm part of the pin as suggested by FR-A-593 569. The present invention also provides displacing means for positive release of the free end of the hook-like part, which is an advantageous provision not found in the prior art. In an embodiment one end of said arm part is formed with a loop to which said pulling ring is coupled.
It is a feature of the preferred embodiment that said hook-like part has a first limb which extends in spaced relation to said arm part and a second limb extending to provide said free end, said first and second limbs being joined at a pre-formed bend.
Advantageously, in the preferred embodiment said displacing means is formed by said pulling ring, the arrangement being such that said pulling ring may be twisted relative to said arm part to cause said free end of said hook-like part to be urged from the position in which it secures the arm part to a position in which it permits said arm part to be released.
In a preferred embodiment the previously known branched locking part of the cotter pin has been replaced with a hook-like part. In use this hook-like part extends under, or preferably over, the handle of the hand-grenade. The free end of the hook-like part is capable of being forced, by twisting the ring-like pulling part, to turn from behind the handle of the hand-grenade in order to enable the arm part to be withdrawn. In this embodiment, the force required to withdraw the pin has been made constant, and inadvertent withdrawal of the pin is not possible. For withdrawal it does not suffice that the ring-like pulling part is subjected to pulling, but it must at the same time be subjected to a twisting movement in order to force the free end of the hook-like part of the cotter pin to turn from behind the handle of the hand-grenade. In addition, the bend of the hook-like part has been made to protrude somewhat, and the pulling ring is of such size and shape that, when turned over the hand-grenade handle, it can be snapped over the said protrusion in order to secure the hand-grenade for the duration of transportation. At this time the pulling ring is tightly pressed against the handle of the hand-grenade and thus cannot be caught by anything adjacent it.
In this embodiment, at that end of the pin which is towards the pulling ring there is formed a loop through which the pulling ring has been fitted. Furthermore, the hook-like part extends preferably over the arm part in such a way that the arm part, together with the hook-like part, forms a loop which is completely closed but capable of being opened by twisting the pulling ring.
In using this embodiment of hand-grenade pin, it is thus not sufficient that the arm part is subjected to pulling, but the pulling ring must first be snapped over the protrusion in the hook-like part. It must then be turned away from over the hand-grenade arm, and be twisted in such a way that the hook-like part turns from behind the hand-grenade handle. Thereafter the straight arm part can be withdrawn from the openings in the hand-grenade handle and body in order to detonate the hand-grenade.
An embodiment of the invention is now described below, by way of example only, in greater detail with reference to the accompanying drawing, in which:-
Figure 1 depicts a hand-grenade pin in its transportation position, and Figure 2 depicts the same pin in a state of readiness in which the pulling part is not secured.
In the accompanying drawing the arm part is indicated by reference numeral 1 and the pulling ring by reference numeral 2. At one end of the arm part 1 a loop 4 has been formed, and the pulling ring 2 has been fitted through it. By mediation of the loop 4, the arm part 1 is connected to a hook-like part 3 on top of the arm part 1. The hook-like part 3 has a first limb which extends in spaced relation to the arm part 1 and a second limb extending to provide the free end, the first and second limbs are joined at a pre-formed bend. The free end of the hook-like part 3 extends over the arm part 1, thus forming a loop which is closed but can be opened by twisting the pulling ring 2. At the bend of the hook-like part 3 there has been formed by bending a protrusion 5. The pulling ring 2 is of such size and shape that it can be turned and snapped over the protrusion 5 at the bend of the hook-like part 3, to occupy the position shown in Figure 1. In this position the pulling ring 2 rests on top of the hand-grenade handle (not shown in the figure, since it is of a conventional structure).
During transportation, the pulling ring 2 of the hand-grenade cotter pin is in the position depicted in Figure 1. Before detonation the pulling ring 2 can be easily forced over the protrusion 5 on the hook-like part 3 and be turned to the position depicted in Figure 2. If no detonation is carried out, the pulling ring can be easily turned back over the handle of the hand-grenade and be snapped over the protrusion 5 in the hook-like part 3. If the cotter pin has been withdrawn entirely before the throwing of the hand-grenade, the straight arm part 1 can be easily pushed into place and be thus re-secured.
The arm part 1, the loop 4 and the hook-like part 3 are preferably of one piece and made from spring wire of suitable thickness, as is also the pulling ring 2.
Thus the embodiment of the present invention provides a very simple and inexpensive hand-grenade pin, its inadvertent withdrawing having been eliminated and the force required for the withdrawing of the pin being constant.

Claims

1. A hand-grenade pin comprising an arm part (1) for fitting through openings in the handle and in the body of a hand-grenade, a pulling part (2) associated with one end of the arm part (1) for use in withdrawing the arm part (1), and a locking part (3) for use in preventing inadvertent withdrawal of the arm part (1) said locking part having a free end for securing the arm part (1), said pulling part comprising a pulling ring (2) adapted to be positioned relative to said arm part (1) so as to engage with said pin in order to secure the hand-grenade for the duration of its transportation, characterised in that said locking part (3) comprises a hook-like part having said free end which engages said arm part (1), said locking part (3), in use, extending about the handle of the hand-grenade when said arm part (1) is secured, means for displacing said free end of said hook-like part (3) so as to release said arm part (1) for the withdrawl thereof, said pulling ring (2) being engageable with a protrusion on said hook-like part (3) for securing the hand-grenade, and wherein said pulling ring (2) is of such size and shape that, when arranged to extend over said hand-grenade handle, it can be snapped over the said protrusion (5) for securing the hand-grenade for the duration of transportation.

2. A hand-grenade pin as claimed in Claim 1, wherein said one end of said arm part (1) is formed with a loop (4) to which said pulling ring (2) is coupled.

3. A hand-grenade pin as claimed in either Claim 1 or Claim 2, wherein said hook-like part (3) has a first limb which extends in spaced relation to said arm part (1) and a second limb extending to provide said free end, said first and second limbs being joined at a pre-formed bend.

4. A hand-grenade pin as claimed in Claim 3, wherein said protrusion (5) is formed at said bend.

5. A hand-grenade pin as claimed in any one of Claims 1 to 4, wherein said displacing means is formed by said pulling ring (2), the arrangement being such that said pulling ring (2) may be twisted relative to said arm part (1) to cause said free end of said hook-like part (3) to be urged from the position in which it secures the arm part (1) to a position in which it permits said arm part (1) to be released.