Note: Descriptions are shown in the official language in which they were submitted.
li71 7~8
--1--
The present invention relates to firearms, and
in particular to a re-chargeable magazine for a firearm.
The invention is especially concerned with the provision
of a firearm having a rotary magazine which can automatically
supply a fresh round to the breech of a firearm so as to be
ready for a fresh firing sequence to commence as soon as a
spent case has been ejected.
Considerable importance is attached nowadays to
obtaining a maximum of performance from a firearm with a
minimum of bulk. The user requires an efficient weapon
which is portable with the minimum of inconvenience.
Magazines of firearms according to the present invention
are capable of accommodating a number of rounds of ammunition
therein so as to use space more economically than has
previously been thought possible.
This factor is of particular importance in a
weapon capable of firing ammunition of relatively large
calibre, eg. 4 cm, such as for example rounds comprising
projectiles in the form of the so-called "rubber bullets",
gas canisters, or grenades or other fragmentation devices.
Accordingly the present invention has particular but not
exclusive application to firearms of this type. Conventional
practice is to provide a disposable magazine, 50 that when
one magazine is exhausted it is removed and replaced by a
fresh magazine, already loaded with fresh ammunition.
Unless he throws away a magazine which is only partially
exhausted, the user may therefore run out of ammunition and
be obliged to change magazines at an extremely inconvenient
moment. Normally there has been no possibility of re-
charging a partially exhausted magazine without disengagingthe magazine from the firearm. Where the firearm is for
large calibre ammunition, this problem can be particularly
acute because considerations of bulk prevent the use of
a magazine capable of holding more than a few rounds.
,7~,
7QI~
--2--
An advantageous feature of the present invention
is that it makes possible the provision of a magazine which
can be re-loaded at any time with any number of rounds of
ammunition up to its maximum capacity, without the necessity
for removal of the magazine from the firearm.
According to the present invention, there is
provided a firearm having a rotary magazine comprising
a magazine body defining around part of its
circumference an opening through which a round of ammunition
can be inserted or withdrawn, and around a remaining part
of its circumference defining a circumferential restraint
through which a round cannot be inserted or withdrawn;
a carrier rotatable within the body about a
carrier axis and having radially extending portions adjacent
pairs of which define positive locations in which a round of
ammunition can be accommodated on insertion through the
opening, rounds being slideable longitudinally in said
positive locations;
res.lient carrier biasing means for urging the
carrier to rotate in a particular bias direction;
a guide member moveable across the opening;
said guide member having a guide surface facing
against the bias direction so that a round inserted through
the opening is guided into one of said positive locations
and simultaneously rotates the carrier against its bias;
said guide member having a round-retaining surface
facing in the bias direction which can co-operate with one of
the positive locations to positively retain the first-
inserted round against circumferential and radial movement;
and
restrainin~ means for holding the guide member in
a position such that the guide surface faces the opening
whenever the carrier occupies the position corresponding to
one in which the magazine contains less rounds of ammunition
than its maximum capacity, the guide member being moveable
against the bias direction during movement of the carrier
corresponding to insertion of the final round so that the
70l~
first-inserted round may then pass through the position
occupied at other times by the quide means.
Conceivably the guide member restraining means
might comprise a resilient guide bias means urging the guide
member to move in the bias direction against a stop.
Advantageously, however, the restraining means
comprises first locking means for positively locking the
guide member to the body whenever the magazine contains
less rounds of ammunition than its maximum capacity, the
locking means being releasable automatically when the carrier
moves against the bias direction as the final round is
inserted.
Preferably second locking means are provided for
positively locking the guide member to the carrier during
insertion of the final round when the first-inserted round
is positively held between its positive location in the
carrier and the round-retaining surface of the guide member.
In a convenient arrangement, the first and second locking
means comprise a detent member slideable in a bore passing
through the guide member in the direction of the carrier axis,
said detent member being of such a length as to project from
a surface of the guide member at all times, a projecting
end of the detent member being constrained by contact of its
other end with an end face of the carrier to remain within a
first depression in the body whenever the carrier occupies
the position corresponding to one in which the magazine contains
less rounds of ammunition than its maximum capacity, a second
depression being provided in the said end face of the carrier
into which the said other end of the detent member can move
so that it clears the first depression during movement of
the carrier corresponding to insertion of the final round.
Advantageously, means are provided for limiting
the maximum rotation of the carrier relative to the magazine
body. Thus it can be ensured that a positive bias of the
resilient bias means is always maintained.
11717~
--4--
The means for limiting the maximum rotation of the
carrier can conveniently be in the form of a stop on the
carrier which cannot pass the detent member.
In a convenient arrangement, there is provided
an annular groove in the end face of the carrier into which
the detent member is constrained at all times to project by
contact with the body, the second depression being provided
in the base of the annular groove and the stop being in the
form of an obstruction in the groove.
Carrier indexing means are normally provided for
holding the carrier in positions such that each successive
round of ammunition can be held against the carrier biasing
means aligned in the breech with the barrel.
Conveniently the carrier indexing means is a
ratchet device acting between the carrier and the body.
Advantageously the firearm is provided with a
longitudinally moveable breech block which can push forward a
round of ammunition in a positive location in the carrier
aligned with the barrel to engage the round positively with
the breech end of the barrel.
Advantageously the firearm is provided with a
longitudinally moveable firing pin which can move forward to
strike the rear face of a round of ammunition only when the
breech block occupies a forward position.
Preferably the firing pin has a mechanical
interaction with the carrier indexing means such that after
the breech block has pushed a round of ammunition fully
forward and the firing pin has reached a forward position
in which it can fire the round of ammunition, the carrier
indexing means is disengaged to permit the carrier to turn
to a position where the next successive round is brought
into alignment with the breech.
Desirably the carrier indexing means comprises
a catch having a slotted pivotal mounting on the body, the
catch being biased towards a position where it engages one
of a number of spaced projections on the carrier to restrain
1~7~70~
--5--
rotation thereof, and the said ~echanical interaction comprises
means for disengaging the catch when the firing pin is retracted
with the breech block from its most forward position, the catch
immediately returning by reason of its slotted pivotal mounting
to a position clear of the said one projection where it can
engage the next succeeding projection on subsequent rotation
of the carrier under its resilient bias.
Preferably the breech block has a lip which can
engage around the rim of a round aligned therewith, so that
after firing the spent case of a round can be withdrawn
longitudinally by rearward movement of the breech block.
When the spent case is thus withdrawn into alignment
with the magazine opening, if the carrier catch has been freed,
the carrier thus indexes around to bring the next round in the
lS magazine (if any round is present) into alignment with the
barrel, and to eject the spent case throuqh the opening under
the force exerted by the carrier bias and guided by the guide
surface of the guide member.
The invention will now be described by way of example
only with reference to the accompanying drawings, in which
Figure 1 is a side elevational view on the line
I-I of Figure 2 of an embodiment of firearm in accordance
with the invention,
Figure lA shows a part of Figure 1 to an enlarged
scale,
Figure 2 is a plan view part in section, of a part
of the firearm shown in Figure 1,
Figure 3 is a sectional end elevation on the line
III-III of Figure lA,
Figure 4 is a sectional end elevation on the line
IV-IV of Figure 2,
Figure 5 is a sectional part view on the line V-V
of Figure 4,
Figure 6 is a sectional part view on the line VI-VI
of Figure 3,
Figure 7 is a sectional part view on the line VII~VII
of Figure 3,
11 ~17~
--6--
Figure 8 is a side elevational view of a round of
ammunition suitable for use in the firearm of Figures
1 to 7, and
Figure 9 is an end elevational view of the round of
ammunition shown in Figure 8.
As seen in Figures 1 to 7, a self-loading firearm com-
prises a barrel 1, a rotating magazine assembly 2, a firearm
body 3 housing a breech block and firing mechanism, a butt
assembly 4 and a pistol grip 5. A trigger 5 is pivoted at 7
in the base of the pistol grip 5, and is b_ased to rotate
anticlockwise about the pivot 7 by means of a double leaf
spring 8 stressed against the rear of the pistol grip 5. A
trigger guard 9 protects the trigger against accidental
operation.
Pivoted at 10 to the forward upper portion of the trigger
is a link member 11, which extends generally rearwardly from
its pivot point 10. Pivotally fixed at a pivot point 12 to
the rear end of the link member 11 is a rearward extension of
a first toggle bar 13. Toggle bar 13 is pivotally connected
at its forward end by pivot 14 to a breech block 15 slideable
longitudinally in the body 3. Pivotally connected by a pivot
16 to an intermediate point on the first toggle bar 13 is a
second toggle bar 17 which extends rearwardly from the pivot
16, and is itself pivoted by a pivot 18 to the body 3.
Slideable longitudinally within a channel 19 in the
breech block 15 is a firing pin 20 having a hardened forward
tip portion 20A, and a side cheek 20B which can bear on a
pin 21 held captive in a transverse bore in the body 3.
(Fig. 2)
A strong helical compression spring 22 provided with a
thrust cap 23 is located rearwardly of the firing pin 20 in
the bore 19 between a retaininq pin 24 and a shoulder 25 of
the bore 19. A relatively weak helical return compression
spring 26 is also located in the bore 19 between a forward-
facing shoulder 27 on the firing pin 20 and a shoulder 28 of
the bore 19.
A sear 29 pivoted to the body 3 by pivot 30 is urged to
turn clockwise tas viewed in Figure 1) about the pivot 30 by
a spring 31, towards engagement with the firing pin 20. The
tip of the sear 29 can engage, through a longitudinal slot
32 in the breech block 15 with a bent 33 on the firing pin 20,
to restrain the firing pin from forward movement. A sear
control pin 34 of generally cylindrical form can slide in a
transverse bore 35 in the firing pin 20. The pin 34 has a
flat 36 formed on its lower portion, but not extending to its
lower end. The width of the pin 34 at the section of the flat
36 is such as to permit that section of the pin to slide along
a longitudinal slot 37 inthe breech block 15 which is of a
width less than the full diameter of the pin 34. The length
of the flat 36 in the direction of the pin axis is such as to
permit a limited sliding transverse movement along the bore 35,
but escape of the pin 34 is prevented by abutment of its full
diameter portions against the edges of the slot 37. During
assembly, the pin enters the slot 37 through a keyhole 38 in
the breech block 19, but during normal operation of the fire-
arm the relative movement of the firing pin 20 and the breechblock 19 is limited so that the pin 34 does not become aligned
with the keyhole 38.
The magazine assembly 2 comprises a magazine body 40 and
a spindle 41. The spindle is secured to the firearm body 3
by means of a screw 42, and the magazine body 40 is secured
to the spindle by means of a screw 43. A spigot 44 on the
body 40 locates within a corresponding socket on the body 3
and correct alignment is ensured by an alignment pin 45
(Figure 2) secured to the body 40 and fitting closely within
a corresponding alignment recess in the body 3. Mounted for
rotation on the spindle 41 is a star wheel assembly comprising
a forward star wheel 46 and a rearward star wheel 47 locked
. to rotate together by means of dogs. The star wheels 46, 47
are of mutually similar transverse cross-section as best seen
117~708
in Figures 3 and 4, each comprising respectively five evenly
spaced radially-extending arms 48, 49 shaped to define a
slightly less than semi-circular recess 50, 51 between each
adjacent pairs of arms, the recesses of the two star wheels
being axially aligned with one another. The star wheel
assembly 46, 47 is urged to rotate in a clockwise direction as
viewed in Fiqure 3, by means of a pair of helical torsion sprin~s
52, 53 mounted around the spindle 41. At their forward end,
the springs 52, 53 have tails which bear against a cross-pin
54 to restrain rotation around the spindle. At their rearward
ends, the springs 52, 53 have tails which engage in corres-
ponding holes in the forward face of the star wheel portion
47. Thus when the star wheel assembly 46, 47 is turned
anticlockwise (as viewed in Figure 3), a torsional restoring
force is provided by springs 52, 53. A certain degree of
torsion is imparted to the springs 52, 53 during assembly so
that they bias the star wheel assembly to turn clockwise as
viewed in Figure 3.
Each arm of the star wheel 47 is provided with a rear-
wardly projecting tail 55 which runs freely, as the star wheel
rotates, in an annular recess 56 in the adjacent end face of
the body 3. As seen in Figure 5, a catch 57 having a slotted
pivotal mounting 58 in the body 3 is urged forwardly by the
action of a spring loaded plunger 59, the forward movement
of the catch being limited by a stop pin 60. The catch 57
has a hooked portion 61 adapted, when in its forward position,
to engage and restrain an adjacent tail 55. The catch 57also has
a cam face 62 engageable by the outer end of the pin 21.
- A loading arm 63 is provided comprising a pair of curvedarms 64, 65 freely pivoted respectively on the spindle 41 just
ahead of the star wheel 46, and on a boss formed on the for-
ward portion of the star wheel 47. The arms 64, 65 are linked
rigidly together by a longitudinally extending guide bar 66.
Referring particularly to Figures 3, 6 and 7, a floating
pin 68 received in a longitudinal bore in the forward curved
~17~70~
g
arm 64, where it is held captive between the front face of the star
wheel 46 and the rearward face on the body 40. As shown, the
forward end of the pin 68 is received in a curved depression
69 in the forward face of the body 40, and the rearward end
of the pin 68 is received in an annular grove 70 in the
forward face of the star wheel 46. A cross pin 71 fixed by
adhesive in a radical bore in the star wheel 46 extends across
the groove 70 and acts as a stop to prevent the star wheel
assembly 46, 47 making substantially more than a single
revolution relative to the loading arm 63.
The pin 68 is of a greater length than the depth of the
groove 70 plus the thickness of the forward curved arm 64, so
that normally the pin 68 projects into the depression 69 so
that the loading arm 63 is locked stationary with the body 40,
while the star wheel assembly can rotate relative thereto, the
groove 70 providing clearance for the pin 68.
A conical depression 72 is provided in the base of the
groove 70, adjacent the cross pin 71. When the star wheel
assembly 46, 47 has completed almost a full revolution relative
to the body 40 from the position illustrated, the end of the pin
68 within the groove 70 can enter the depression 72, which is
of sufficient depth to enable the other end of the pin 68 to
clear the depression 69. The loading arm 63 can then move
relative to the body 40 between limits set by an opening 73
for the insertion of rounds of ammunition therein, the dis-
engagement of the pin being facilitated by the curved shape
of the depression 69. During this movement the star wheel 46
and the loading arm 63 are locked together by the pin 68.
The round of ammunition for which the firearm is designed
is shown in Figures 8 and 9. It comprises a cylindrical case
74 which contains a projectile (not shown) such as for
example a so-called rubber bullet. The round is also provided
with a projecting rim 75 at its rearward end, and in the
rearward face 76 there is provided a percussion cap 77 by
which the rounds may be fired. The case is designed so as to
11 ~ 170E~
-- 10 --
be substantially self-supporting, ie insertion into a
supporting chamber to prevent rupture of the case when the
round is fired is unnecessary.
Rounds may be inserted into the magazine through the
opening 73. Entry of a fresh round is facilitated by a
recessed portion 78 on the forward face of the magazine body
40, bounded by a chamfered portion 79. After insertion
through the opening, a round is located in a corresponding
pair of recesses 50, 51 which provide a positive location
therefor in the star wheels 46, 47. As the star wheel
assembly is rotated, the forward end of the casing 74 is
restrained from radially outward movement by a part-circular
rim 80 which extends around the whole of the forward face
of the body 40 with the exception of the region of the
opening 73 (see Figure 3). At the rear end, the casing is
restrained from radially outward movement by an arcuate rim
81. The casing is restrained from axial movement around the
whole circumference of the body except the region of the
opening 73 and the breech region, by a radially inwardly
directed lip 82 behind which the rim 75 locates. In the
region of the breech, the round is restrained axially by a
lip 39 on the breech block 15. The concave surfaces of the
curved arms 64, 65 of the loading arm 63 are approximately
semi-circular for a reason explained hereinafter, the radius
being approximately equal to that of the casing 74.
The barrel lis provided at its breech end with a very
short chamber in the form of a socket portion 83 in which the
forward end of a round can be received. The socket portion
83 has a shoulder 84 which the round cannot pass, and entry
to the chamber is facilitated by a short chamfered section 85.
In use of the firearm, any number of rounds up to five
may be placed in the magazine by successive insertion through
the opening 73. As the first round is inserted, its entry is
facilitated by the recess 78 and chamfered portion 79. The
loading arm 63 is locked by the pin 68 in the position
1 ~7 t7~8
-- 11 --
illustrated. The loading arm hence cannot pivot to a
position where it hinders entry of the round. As the round
is pressed inwardly into position the arms 64, 65 guide the
round so that it moves also in an anticlockwise direction
(as viewed in Figure 3), towards alignment with the barrel,
ie towards the breech position. The casing 74 of the round
thus bears on the arms 48, 49 of the star wheels 46, 47 to
move the star wheels anticlockwise (as viewed in Figure 3),
against the torsional bias of the springs 53, 54 until the
round is fully received in a corresponding pair of recesses
50, 51. As the round reaches the position where it is aligned
with the barrel 1 the hook 61 of the catch 57, under the action
of the spring-loaded plunger 59, snaps into place behind the
tail 55 of an arm 49. The star wheel assembly is hence held
in this position against the bias of the springs 53, 54 by a
ratchet action of the catch 57, with the round in the breech
aligned with the barrel.
A second, third and fourth round may be inserted in
exactly the manner described above. As the rounds move
around the magazine they are restrained inwardly in the
recesses 50, 51 of the star wheels 46, 47 and outwardly by
rims 80, 81 whilst longitudinal movement of the rounds is
restrained by lips 39 and 82 engaging rims 75.
However, when it is desired to insert a fifth round, the
loading arm obstructs the path of the first round. This
difficulty is overcome as follows. As the fifth round is
inserted, the star wheel 46 moves to the position in which
the recess 72 comes into alignment with the pin 68. As the
first round pushes against the loading arm, the pin 68 is
urged by the camming action of the curved surface of the
depression 69 to move into recess 72, so that the loading
arm becomes simultaneously unlocked from the magazine body
40, and locXed instead with the star wheel 46. Hence as the
action of inserting the fifth round continues, the first
l t'717~l~
- 12 -
round moves round into the opening 73. However, the first
round is prevented from escaping through the opening 73 by
the loading arm 63 locked to the star wheel 46 so that the
semi-circular recesses 50, 51 together with those of the arms
64, 65, enclose the round over about three-quarters of its
circumference.
When the trigger 6 is pulled with the magazine 2 loaded,
the action is as follows. The link member 11 is moved rear-
wards and is hence forced to pivot anticlockwise (as viewed
in Figure 1). The pivot 12 is thus forced to move upwards,
so that the toggle mechanism comprising the first toggle bar
13 and the second toggle bar 17 begins to straighten. The
breech block 15 is hence moved forward by virtue of the
pivotal connection 14, carrying with it a round positively
engaged behind the lip 39. As the breech block moves forward,
the round slides longitudinally through its recesses 50, 51
to locate in the socket 83 in the barrel 1.
As the breech block moves forward, the firing pin 20 is
held on the sear 29, so that the spring 22 becomes compressed
between the firing pin 20 and the retaining pin 24. When the
toggle mechanism 13, 17 reaches its fully straightened
position, the round is fully engaged in the socket 83 and
the breech block is safely locked against rearward movement.
A small further trigger movement brings the toggle mechanism
to a position where it is locked slightly over-centre with
the upper surface of the second toggle bar 17 bearing on the
pin 34 and pushing it upwards to disengage the sear 29 from
the firing pin 20. The firing pin then shoots forward under
the action of the spring 22, until it reaches the position
shown in Figure 1, where the thrust cap 23 bears on the
shoulder 25. Thereafter the firing pin continues forward at
high speed, under its own inertia, so that its hardened tip
20A strikes the percussion cap 77 to fire the round. It will
be noted that the casing of the round is almost totally un-
supported at the time of firing.
il'717~
As the firing pin moves forward, it compresses the return
spring 26 between the shoulders 27 and 28. As the firing pin
approaches the firing position, the cheek 20B contacts the pin
21 and forces it outwards by a camming action on to the side
surface of the firing pin 20. The outer end of the pin 21 now
projects in front of the cam face 62, but only if the firing
pin has shot fully forward to fire the round.
As the trigger 6 is released, it returns under the action
of the leaf spring 8, the toggle mechanism 13, 17 is pulled
down by the return of the link 11, and the breech block 15 is
hence drawn back towards its original position, taking with
it the firing pin 20, and the spent case of the fired round
which is held by the lip 39.
During this return movement the firing pin remains in a
forward position relative to the breech block (although
retracted clear of the front face of the breech block by the
spring 26). The pin 21 is thus held outwardly during the
return movement by contact with the flank of the firing pin.
As the breech block moves back, the pin 21 bears on the face
62 of the catch 57, to pull the catch backwards and disengage
the hooked portion 61 from the adjacent tail 55. The star
wheel assembly 46, 47 is thus freed from the catch 57 which
now moves downwardly in its slotted pivot to clear the pin 21
and snap into position ready to catch the next succeeding
tail 55. The star wheel assembly 46, 47 is restrained from
rotation under the action of the springs 52, 53 until the
spent case has cleared the socket 83 and the chamfered portion
85, and the breech block has cleared the star wheel 47. When
this stage is reached, the star whee~ assembly is freed to
index forward under the action of the springs 52, 53 until
the catch 57 engages the next succeeding tail 55. The spent
case is thus automatically ejected through the opening 73, and
the next round (if any) in the magazine is automatically
indexed around into alignment with the breech block 15 and
the socket 83 where it is ready to fire. It should be noted,
11717~18
- 14 -
however, that this sequence can occur only if the firing pin
20 has been released and moved forward to fire a round, thus
countering the possibility of a live round being accidentally
ejected.
When the breech is fully retracted the sear 29 moves
under the bias of the sear spring 31 into engagement once more
with the bent 33 on the firing pin.
As long as the magazine contains another round, the
sequence can be repeated and all of the rounds in the magazine
may thus be fired in rapid succession by repeated operation of
the trigger.
If it is desired to remove rounds from the magazine with-
out firing, this may be achieved by manually depressing the
tail tvisible in Figures 2 and 5) of the catch 57~ whereupon
the star wheels 46, 47 are released and the rounds are ejected
automatically in sequence in similar manner to the ejection of
rounds when spent. Further rotation of the star wheel
assembly could release all toxsional pre-stress in the springs
52, 53 and so detract from subsequent proper functioning of
the magazine feed. This is prevented by the pin 68 coming
against the cross pin 71 just after the last round is ejected.
