Safety pin for hand grenades

Abstract

 A safety mechanism for a hand grenade consists of a safety pin 12 for cooperation with an ignition head 3 and a safety arm 11. The safety pin is shaped like a clamp 10 made of spring steel, with one end 1 designed to be led through overlapping holes 2 in the ignition head 3 and the safety arm 11. Further, it has a second end 4 designed to be twisted over the ignition head 3 and which is secured by being led past protruding pins 6, 7, 8, 9 on the ignition head 3 or the safety arm 11.

Description

1. Field of the invention

[0001] The present invention involves a device for locking the safety flank in the ignition mechanism of a hand grenade, preferably a smoke hand grenade.

2. Background of the invention

[0002] The present invention involves a device developed in connection with a user clobject which specifies that the safety pin, after its release, shall be easy to reinsert, thus protecting the grenade in a satisfactory manner. A brief description of the ignition mechanism of a hand grenade will be provided in the following.

[0003] A hand grenade is fired with the aid of the ignition mechanism, which consists of the following components: A delaying element with blasting cap and an ignition mechanism with striking arm/hammer mounted on an ignition head, which is screwed into the end of the grenade; an explosive charge, which is fastened to the delaying element; a safety arm made of metal, which keeps the hammer cocked in the ignition mechanism; and a safety mechanism, which locks the safety arm to the ignition head and prevents the safety arm from popping up and releasing the firing lock.

[0004] The present invention is intended to replace the conventional safety mechanism, which consists of a metal pin fastened to a metal ring. The pin locks the safety arm to the ignition head and prevents the release of the firing lock by simultaneously running through overlapping holes in the safety arm and the ignition head. The pin, which is divided lengthwise, is further locked by being bent outward in the protruding end after it has been put in place. Upon deactivation of the safety mechanism, the pin is disengaged with the aid of the ring, which is fastened at the other end. Reinserting the pin, when this is desirable, will be difficult, since the pin is bent outward a bit at the end after being pulled out. If the pin has successfully been reinserted, it must be bent out again with a tool, in order to obtain an acceptable safety.

[0005] In addition to conventional safety mechanisms such as those mentioned above, there is a known safety device for hand grenades from DE Offenlegungsschrift 4.140.902, consisting of a protective cap, a safety pin, a pulling ring and a locking element. This device consists of so many loose parts that it is difficult to reinsert the safety mechanism, if one should change one's mind. Furthermore, the pulling ring sticks out above the grenade when stored, which makes it not very compact and prone to damage in a fall.

[0006] FI 69368 describes a safety pin with accompanying pulling ring. The pin has two ends, which rest against each other when the pin has been pulled, preventing the pin from being reinserted in the ignition head. Thus it is difficult to reinsert the pin if the user wishes to reactivate the safety mechanism.

3. The object of the invention

[0007] One object of the invention has been to devise a simple safety mechanism for hand grenades whereby the deactivation of the safety can readily be reversed.

[0008] Another object has been to produce a more reliable safety mechanism.

[0009] Yet another object of the invention has been to produce a safety mechanism that is more compact than previously known safety mechanisms.

4. Brief description of the invention

[0010] These objects are achieved with a safety mechanism according to the attached independent patent clobject 1, which contains a safety pin for cooperation with an ignition head and safety arm, where the safety pin is shaped like a clamp made of spring steel, with one end designed to be threaded through a hole in the ignition head and safety arm, and the other end designed to be twisted over the ignition head and secured by being drawn past protruding impediments on the ignition head or safety arm.

[0011] Additional embodiments of the invention are indicated by the subsequent dependent claims.

5. Brief description of the drawings

[0012] 

• Figure 1 shows a safety pin according to the invention.
• Figure 2 shows the safety pin mounted on a smoke hand grenade, as seen from the side.
• Figure 3 shows the same smoke hand grenade as seen from the rear.

6. Preferred embodiments of the invention

[0013] Figure 2 shows a hand grenade equipped with a safety mechanism in accordance with the invention. The grenade is equipped with an ignition head 3 and a spring loaded safety arm 11. In the ignition head 3, and under the safety arm 11, there is a firing lock (not shown). The safety arm 11 is held in place by a safety pin 12.

[0014] When in use, the grenade is held in one hand. The hand holds the safety arm 11 firmly against the body of the grenade. The safety pin 12 is pulled by the other hand, whereupon the grenade is thrown. When in flight, the safety arm 11 pops open and releases the firing lock, whereupon the grenade is detonated after an appropriate delay.

[0015] Figure 1 shows the actual safety pin 12. The safety pin 12 is in the form of a clamp, with a first end 1, a mid-section 10 and a second end 4. It may be made of spring steel wire, with a diameter of 2-3 mm. When mounted, the first end is threaded through an overlapping hole 2 in the safety arm 11 and the ignition head 3. The end 4 of the locking arm on the safety pin 12 should not be longer than will allow for it to slide over the edge 5 of the safety arm 11 with ease. The safety pin 12 is then twisted toward the top of the ignition head at the same time that the clamp is pressed in at mid-section 10, such that the other end 4 slides over locking notches 6 & 7 on the safety arm 11. In an alternative form of the safety mechanism, corresponding locking pins may be cast into the ignition head 3. When the pressure on the mid-section 10 is relieved, the safety pin 12 will be locked. Identical locking notches or locking pins can be situated on both sides of the ignition head. The first end 1 of the safety pin may then be inserted from whichever side the user chooses. When the grenade is being safety-deactivated, the described locking sequence is reversed.

[0016] Thus it can be see that the safety pin, in the present invention, is not locked upon being split and bent, and so is not subject to the aforementioned problems with respect to reinsertion. Furthermore, it is presumably easy to manufacture, as it consists solely of a simple steel wire made of spring steel. This also provides for a simple, quick installation.

[0017] The present invention also makes it possible to use a smaller, simpler ignition head. Such an ignition head is often molded into a plastic material. The simple construction, which can be used in a safety mechanism according to the invention, enables the component to be molded without producing critical tensions in the plastic material. This reduces the likelihood of cracking open during the qualification test, and also during long-term storage under the constant pressure to which the threaded section is subjected after being screwed into the grenade. This storage period can last 10-20 years.

[0018] The invention also provides for a safer deactivation of the grenade safety mechanism. With the conventional solution, the pin must be pulled out against a force of 8-12 kp. This increases the likelihood of loosing one's grip on the grenade during deactivation of the safety mechanism, especially when wearing snow-covered mittens. The new safety mechanism also requires a corresponding force in order to release the lock. However, this power-consuming operation takes place before the pin is withdrawn. Thus the last stage, which deactivates the safety mechanism, can be carried out without the use of force, and the likelihood of loosing the grenade is minimized.

Claims

1. Safety mechanism for the hand grenade, consisting of a safety pin for cooperation with an ignition head and a safety arm
characterized in that the safety pin (12) is shaped like a clamp of spring steel, with one end (1) designed to be led through a hole in the ignition head (3) and safety arm (11), and the other end (4) designed to be twisted over the ignition head (3) and secured by being carried past protruding stops (6, 7, 8, 9) on the ignition head (3) or the safety arm (11).

2. Safety mechanism according to clobject 1,
characterized in that the stops consist of locking lugs (8, 9) on the ignition head (3).

3. Safety mechanism according to clobjects 1 and 2,
characterized in that the protrusions consist of locking notches (6, 7) on the safety arm (11).

4. Safety mechanism according to clobjects 2 and 3,
characterized in that the ignition head (3) is made of plastic.

5. Safety mechanism according to one of the aforementioned clobjects,
characterized in that the locking notches (6, 7) or the locking pins (8, 9) are placed on both sides of the ignition head (3), such that the safety pin (12) can be reinserted and secured from both sides of the ignition head (3).

Drawing