Hunting Gun With Floating Bolt Provided With A Device For Locking The Bolt Head In The Bolt Breech Upon Firing

Abstract

The hunting gun has a bolt assembly comprising two parts, namely a locking head and a floating element with a spring interposed between the two parts. The locking head comprises essentially one or more projections adapted to engage corresponding recesses in the cylindrical internal surface of the breech and a surface inclined with respect to the breech axis and adapted to engage a mating surface of the floating element. Upon firing the gun recoils but the floating element, being free in the gun, tends to keep its position and keeps the locking head with its projections in engagement with the grooves in the breech. Thus, there is a delay in the opening of the cartridge chamber, which prevents unlocking of the gun in the charge explosion step, i.e. at the time of greatest gas expansion. When the recoil force has decreased to a predetermined extent the spring pushes back the floating element which slides with its inclined surface on the mating surface of the locking head permitting the latter to lower and disengage its projections from the recesses in the breech so that the locking head can also recoil under the action of the residual force of the spring.

Description

This invention relates to a hunting gun, of the kind disclosed in the Italian Patent No. 762319 issued to the applicant of this invention.

The hunting gun disclosed in the above Italian patent is provided with a bolt assembly consisting in two portions, namely a locking bolt head and a floating element adapted to axially reciprocate with respect to the locking bolt head and to unlock it during the movement in one of the two directions, a spring being interposed between said two portions.

Upon firing, the weapon undergoes a recoiling action due to the pressure developed by gases generated upon the explosion of the cartridge charge caused by the firing pin, however, the floating element being free with respect to the breech, accomplishes by its inertia an axial movement relative to the locking bolt head, thereby compressing the spring interposed between the floating element and the bolt head. This prevents the weapon from being unlocked during the charge explosion step, i.e. at the time of maximum gas expansion thereby avoiding a premature weapon unlocking. Only when the recoiling action has been attenuated to a predetermined value, the spring reacting to the compression to which it had been subjected by the inertial mass of the floating element, throws back again the floating element which causes the unlocking of the locking bolt head, so that also the latter is recoiled partly under the action of the spring and partly under the action of the residual gases. This causes in a conventional manner the cartridge ejection, the loading of the weapon and the locking of a fresh cartridge in the cartridge chamber.

In the above Italian patent the locking device of the locking bolt head comprises a push rod, which in the locking position of the locking bolt head is placed between the locking bolt head and a shoulder provided in the breech, and is adapted to be disengaged from the breech during the return stroke of the bolt floating element and to be entrained by the floating element during its stroke.

This invention aims to make the locking device of the bolt head more simple and economical.

More particularly the hunting gun according to this invention is characterized in that the locking bolt head comprises a first surface provided with one or more projections adapted to engage in corresponding recesses provided in the cylindrical internal surface of the breech, a second surface adapted to engage a mating surface of the floating element of the bolt and to slide thereon during the initial intertial movement of the floating element so as to maintain the projections of the first surface in the corresponding recesses of the second surface, said two mating surfaces under these conditions being substantially parallel to the breech axis, and a third surface, inclined with respect to the breech axis and adapted to engage a mating surface of the floating element and to slide thereon during the next back movement of the floating element so as to permit the projection or projections to disengage from the corrsponding recesses provided in the breech.

The invention will be more apparent from the following description, merely given by way of example of an embodiment of the invention taken in connection with the accompanying drawing, wherein:

FIG. 1 is a fragmentary axial section of a hunting gun according to the invention, in the firing step of the weapon;

FIG. 2 is a fragmentary axial section of the gun shown in FIG. 1, in the unlocking step of the weapon;

FIG. 3A is a side elevation view of the locking bolt head of the weapon shown in FIGS. 1 and 2;

FIG. 3B is a top plan view of the locking bolt head shown in FIG. 3A; and

FIG. 4 is a side elevation of the bolt floating element of the weapon shown in FIGS. 1 and 2.

Referring now to FIG. 1, there is shown the locking bolt head 1 which, upon firing, locks the cartridge 2 into the cartridge chamber 17 through the engagement of three curved ribs 3 extending from a curved surface 15 of the bolt head into corresponding curved grooves (see FIG. 2) provided in the breech 7. This engagement is assured by the engagement of a flat 13 (see FIG. 4) provided in the floating element 9 of the bolt, with a flat 16 (see FIG. 3A) of the locking bolt head 1. A spring 10 is placed between the locking bolt head 1 and the floating element 9. The locking bolt head 1 is also provided with two inclined surfaces 8 (see FIGS. 3A and 3B) adapted to cooperate with mating inclined surfaces 12 provided in the floating element 9.

In FIG. 1 the weapon is shown at the time of firing. The hammer 18 has been brought by the actuation of the trigger (not shown) in contact with the firing pin 19 which by striking the explosive charge of the cartridge 2 causes the explosion of the charge with resulting gas release and ejection of the small shot charge 20. The weapon recoils by reaction against the shooter shoulder, however the bolt floating element 9, being out of engagement with the remainder of the gun, has the tendency to maintain its own position thereby compressing the spring 10 interposed between the floating element and the locking head 1. During this step the flat 16 of the locking head slides with respect to the flat 13 of the floating element 9 which keeps the locking head in the position shown in FIG. 1, with the ribs 3 in engagement within the grooves 14 in the breech 7. Therefore, in this step the locking head is locked and closes the cartridge chamber 17. Thus, there is a delay in the cartridge chamber opening which prevents unlocking of the weapon in the charge explosion step, i.e. at the time of greater gas expansion. Therefore, at the time more dangerous there will never be a premature opening of the weapon.

As the recoil force is decreased to a predetermined value at which the spring 10 has been calibrated, the latter pushes back the bolt floating element 9 by means of the force stored during the compression of the spring 10 and as the inclined surfaces 12 of the floating element 9, during this recoil movement, lie at the inclined surfaces 8 of the locking head 1, the latter is able to lower itself, due to the mutual sliding movement of the mating surfaces with respect to the breech 7 until the ribs 3 are disengaged from the grooves 14 of the breech 7. At this time also the locking head 1 can recoil under the action of the residual force stored by the spring 10 and by means of the residual gases opens the cartridge chamber thereby permitting the cartridge case 21 to be ejected. This return step of the bolt floating element 9 and the locking head 1 is shown in FIG. 2.

During the return stroke the bolt will cause in a conventional manner the reloading and locking of the gun which will be ready for a new shot.

As it is seen, the locking and unlocking of the weapon are accomplished by two elements only, namely the locking head 1 and the bolt floating element 9, while in the above Italian patent these functions were accomplished by three elements, namely the locking head, the floating element and the push rod. The locking and unlocking device of the weapon therefore results simplified with respect to that of the Italian Patent No. 762,,319.

While an embodiment only of this invention has been shown and described, it should be understood that various changes and modifications cana be devised without departing from the scope of the invention. Thus, for example, while in the specific embodiment described herein the projections of the locking head and the recesses of the breech intended to receive said projections are in number of three, these projections and recesses can be more or less than three and could be reduced to one only.

Claims

What I claim is:

1. A hunting gun having a cartridge chamber and a breech extending along an axis including a cylindrical internal surface, said gun provided with a bolt assembly comprising a locking bolt head and a floating element adapted for axial movement in back and forth directions with respect to the locking bolt head and to unlock it during the movement in one of the two directions, and a spring interposed between said locking bolt head and said floating element, characterized in that said locking bolt head comprises a first surface provided with at least one projection adapted to engage in corresponding recesses provided in the cylindrical internal surface of the breech, a second surface adapted to engage a first mating surface of the floating element of the bolt assembly and to slide thereon during the initial inertial movement of the floating element so as to maintain said at least one projection of the first surface in the corresponding recesses of the second surface, said two mating surfaces under these conditions being substantially parallel to the breech axis, and a third surface, said third surface being inclined with respect to the breech axis and adapted to engage a second mating surface of the floating element and to slide thereon during a next back direction movement of the floating element so as to permit said at least one projection to disengage from the corresponding recesses provided in the breech.

2. A hunting gun according to claim 1, characterized in that said first surface of the locking bolt head, said at least one projection thereof and said recesses provided in the cylindrical internal surface of the breech are curved.

3. A hunting gun according to claim 1, characterized in that said second and third surfaces of said locking bolt head and said cooperating surfaces of said bolt floating element are flat surfaces.

4. A hunting gun according to claim 3, characterized in that said inclined surfaces of said locking bolt head and said bolt floating element merge in the surfaces of said elements substantially parallel to the breech axis.

5. A hunting gun according to claim 1, characterized in that said third inclined surface of said locking bolt head comprises two distinct areas disposed at both sides of said first and second surfaces of said locking bolt head.

6. A hunting gun according to claim 1, characterized in that said locking bolt head comprises a short cylindrical section intended to close the cartride chamber, and a rod-shaped extension carrying said projection and said second and third surfaces cooperating with said first and second mating surfaces respectively of said bolt floating element, and said floating element is substantially cylinder-shaped, said floating element being provided with a longitudinal slot intended to receive said rod-shaped extension of said locking bolt head.