Reconversion device for a gun from semi-automatic to pump operation

A reconversion device permits a rapid conversion from a semi-automatic operation system to a pump system and vice versa for fixed barrel sporting and defense guns without disassembling the gun.

The present invention relates to a reconversion device from a 
semi-automatic operation system to a pump system and vice versa for fixed 
barrel sporting and defense guns. 
The sporting and defense guns presently in use rely normally on a single 
operation principle either of the semi-automatic type such as gas operated 
backward moving barrel guns, fixed barrel guns using the kinetic recoil 
energy, etc., or of the manual pump type based on the movement of the 
cocking rod or handgrip in a direction parallel to the gun barrel guided 
by a tubular magazine mounted on a support structure secured to the 
barrel. 
It is apparent that each of the above mentioned operation principles has 
peculiarities or deficiencies which are not complementary and compel 
almost always to make selective choices in favour of the one or the other 
but which do not comply with all requirements of use. 
Approaches have been already made to combine on the same arm a 
semi-automatic gas operation and a manual pump operation, but they have 
brought to very complex and expensive solutions. 
It is an object of the present invention to provide a reconversion device 
of the above mentioned type which has not the disadvantages of the 
approaches in this sense made up to now, by starting from a particular 
semi-automatic operation type of gun, more particularly that described in 
the Italian Pat. No. 762.319. This gun is of the fixed barrel type using 
the kinetic recoil energy of the arm for the ejection of the cartridge and 
the recocking of the arm. It includes a breech bolt head separated from 
the remaining breech bolt (hereinafter simply referred to as breech bolt) 
with a spring freely interposed between them, having the function of 
making elastic the recoil of the mass of the breech bolt against the 
breech bolt head thus cushioning the recoil serving to automatically 
register the release of the locking system thus providing a delay time at 
the opening, and causing by its reaction to the backward movement of the 
whole breech bolt head--breech bolt system the ejection of the cartridge 
and the recocking of the arm. 
More particularly, the reconversion device according to the invention is 
characterized in that it comprises an annular control handle rotatably 
supported on a ring secured to an end of a tubular cocking rod axially 
slidable on a tubular magazine, said handle and said ring being provided 
with means for their mutual snap action engagement in four positions at 
90.degree. to one another, said handle having, projecting from an end 
front face thereof, two diametrically opposite sectors each ending in a 
tooth and the front face of a support of the magazine, secured to the 
barrel, facing the end front face of the handle having an annular recess, 
with two diametrically opposite passages with a height larger than that of 
the remaining recess, said recess communicating with an annular undercut 
groove in the support, the two passages of the annular recess having a 
larger height being adapted to receive the teeth of the two sectors 
projecting from the end front face of the handle, the four snap engagement 
positions of the handle and the ring secured to the cocking rod 
corresponding, alternately, to the engagement of the teeth of the two 
sectors in the undercut groove in the support of the magazine and the 
disengagement of the teeth of the two sectors from said undercut groove. 
By engaging, by means of a rotation of the control handle the handle teeth 
in the magazine support secured to the barrel, the whole cocking rod group 
is locked to the barrel providing the semi-automatic operation system 
using the kinetic recoil energy of the arm according to the Italian Pat. 
No. 762.319. 
By disengaging the control handle teeth from their seat in the magazine 
support, it is possible, by means of a rotation of the handle, to stop the 
handle in a disengaged position and allow the whole cocking rod group to 
slide in a direction parallel to the gun barrel. There is thus provided 
the pump operation system of the arm according the which the opening of 
the breech bolt and the recocking of the arm is obtained by means of a 
manual movement of the cocking rod. 
The invention has the following advantages with respect to the solutions 
suggested up to now in the field of the reconversion of the sporting and 
defense guns: 
elimination of the to-day existing anchoring on pump guns between braces 
secured to the cocking rod and the breech bolt; 
extreme simplicity and reliability of the system deriving from the 
semi-automatic type operation to which it is associated which completely 
eliminates the gas part thus reducing the number of components to full 
benefit of economy; 
limited overall size of the whole mechanism which enables to completely 
balance the increase in the weight of the arm with respect to the guns 
presently in use and makes easier its manoeverability and transport; 
possibility to shoot both very low energy non lethal ammunition by using 
the manual repetition pump operation system and high stopping power 
ammunition with all the recocking rapidity advantages of the 
semi-automatic operation system. 
A more ample and detailed explanation of the invention is given hereinafter 
it being understood that only for descriptive purposes there is 
illustrated an application of the reconversion device object of the 
invention on a sporting gun of which all those parts are omitted which 
operate in a manner similar to that of the arms at present in use.

The reconversion device according to the invention consists (FIG. 1) of a 
knurled annular control handle 1 mounted on a ring 2 which is internally 
threaded and secured to a cocking rod 3 provided with a handgrip 4 and 
slidable on a tubular magazine 5. 
The annular handle 1 carries on its front side two sectors 6, of which only 
one is shown since the other, quite similar, is in a diametrically 
opposite position, both sectors being provided with a tooth 7 adapted to 
engage an undercut groove 8 in a support 9 of the magazine secured to the 
barrel 10. 
The annular control handle 1 is mounted (FIG. 3) on the threaded ring 2, 
screwed on the cocking rod 3 by means of a flat semicircular spring 11 
which permits a complete rotation through 360.degree. of the control 
handle about an axis with four indexing positions, every 90.degree. one, 
individually determined by the engagement of a wedge folded end 12 of the 
spring with one of four holes 13 provided in the annular control handle 1, 
because of the tension of the spring, but does not permit the longitudinal 
sliding of the control handle in a direction parallel to the barrel of the 
arm. 
The flat spring 11 in fact, because of the tension it undergoes in the 
position it is mounted (FIG. 3), engages both the annular groove 14 in the 
control handle 1 and the groove 15 facing the groove 14 provided in the 
internally threaded ring 2 secured to the cocking rod 3. 
A hook folded end 16 of the flat spring 11 engaging through a hole in the 
ring 2 a notch in the cocking rod 3 determines the tension of the spring 
11 and keeps it still when the control handle 1 is rotated to select the 
type of arm operation. 
The semi-automatic operation of the arm is determined (FIG. 4) by the 
engagement of the tooth 7 of the sector 6 of the control handle in the 
groove 8 of the support 9 of the magazine 5 secured to the barrel 10. 
In this position the cocking rod 3 provided with an appropriate handgrip 4 
is made integral with the barrel 10 secured to the arm by means of the 
plug 17 screwed on the magazine 5. 
To achieve this, starting from the position in FIG. 2 of the control handle 
1, it is sufficient to insert the sectors 6 in the groove 8 of the support 
9 through suitable passages 18 provided in the annular abutment 19 of the 
support 9 defining the groove 8, and to rotate the control handle 1 by one 
step equal to 90.degree. until its sectors 6 are brought in the position 
of FIG. 4. 
During the semi-automatic operation of the arm the extension 20 of the 
cocking rod welded to the latter, which extends by means of the braces 21, 
indicated in the various sectional fragments of FIG. 4, along the whole 
length of the magazine 5 until the inside of the housing 22, never abuts, 
by means of the faces 23 of the braces 21, the face of the inertial mass 
25 of the breech bolt. 
The space left is sufficient to determine the compression of the spring 26 
because of the kinetic recoil energy of the arm and, as a result, the 
opening, the ejection of the cartridge and, next, the return to closed 
position because of the return spring 27 disposed inside the stock 28; 
everything according to the contents of the Italian Pat. No. 762.319 which 
covers this semi-automatic operation system. 
The pump manual repetition operation system of the arm is determined (FIG. 
5) by the sliding, in a direction parallel to the barrel, of the cocking 
rod 3 together with the handgrip 4, the extension 20 and the braces 21 as 
well as the control handle 1 mounted on the threaded ring 2 screwed on it. 
To achieve this, starting from the position in FIG. 2 of the control handle 
2, it is sufficient to rotate it by a step equal to 90.degree., until its 
sectors 6 are brought in the position of FIG. 5, not inserted in the 
groove 8 in the support 9 of the magazine 5 secured to the barrel 10, but 
abutting the front face 29 of the support. 
In this position the extension 20 of the cocking rod 3 welded to the latter 
which extends by means of the braces 21, indicated in the various 
sectional fragments of FIG. 5, along the whole length of the magazine 5 
until inside the housing 22, abuts by means of the faces 23 of the braces 
21 the face 24 of the inertial mass 25 of the breech bolt. 
Thus, it is no longer possible, because of the kinetic recoil energy of the 
arm, the compression of the spring 26 and, as a result, the semi-automatic 
operation of the arm. 
Only by pulling back, at the end of the stroke, the whole above mentioned 
recocking rod group, by means of the handgrip 4, there is effected the 
opening of the arm, the ejection of the cartridge and next, in the 
position of FIG. 5, its return in closed position because of the return 
spring 27 disposed inside the stock 28 since no mechanical correction 
exists between the braces 21 and the inertial mass 25 of the breech block. 
The same return spring 27 also keeps the whole cocking rod group forwardly 
when the arm not being in use, the handgrip 4 is not actuated by hand. 
It is apparent, from the above description, that the transition from the 
semi-automatic to the pump operation is effected without disassembling the 
arm by a simple rotation of the control handle 1 by inserting or not its 
sectors 6 in the groove 8 of the support 9 of the magazine 5. 
The whole reconversion system reaches therefore the purpose of having on 
the same arm two different easily selectionable types of operation which 
amplify its performance making it more responsive to all different 
requirements and conditions of use. 
The invention can be put into practice in other specific manners, different 
from that described, without departing from the spirit and the essential 
technical features of the invention. 
The described embodiment is therefore to be considered, to all effects, as 
illustrative and not limiting; all changes falling within the equivalents 
of the appended claims are understood as included in the claims.