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Claims  |
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I claim:
1. In a retrofit firearm including a preexisting basic firearm and a
retrofit assembly assembled with the basic firearm, the basic firearm
having a receiver, a barrel projecting from the receiver, a firing
mechanism contained in the receiver and including a secondary trigger
supported on and projecting from the receiver to move between ready and
firing positions for releasing the firing mechanism in a firing position
to discharge the basic firearm, the retrofit assembly including a retrofit
housing containing the secondary trigger and at least a portion of the
receiver, a primary trigger supported on the retrofit housing for movement
relative to the retrofit housing between first and second positions
corresponding respectively to ready and firing positions of the secondary
trigger, and operating means for moving the secondary trigger to its
firing position in response to movement of the primary trigger toward its
second position, the improvement comprising a first safety mechanism
including a first blocking member associated with said secondary trigger
and movable between blocking and releasing positions relative to said
secondary trigger, said first blocking member in its blocking position
preventing movement of said secondary trigger to its firing position, and
releasing means for moving said first blocking member from its blocking
position to its releasing position in response to movement of said primary
trigger toward its second position.
2. In a retrofit firearm as set forth in claim 1 the further improvement
including means for urging said first blocking member to and holding it in
its blocking position when said primary trigger is in its first position.
3. In a retrofit firearm as set forth in claim 2 the further improvement
wherein said urging means comprises means for biasing said first blocking
member toward its blocking position.
4. In a retrofit firearm as set forth in claim 3 the further improvement
wherein said first blocking member is supported on said secondary trigger
and said biasing means comprises a spring acting between said secondary
trigger and said first blocking member.
5. In a retrofit firearm as set forth in claim 4 wherein the receiver
includes a trigger guard and the secondary trigger is disposed within the
trigger guard the further improvement wherein said blocking member in its
blocking position is engagable with an abutment surface defined by said
trigger guard.
6. In a firearm as set forth in claim 1 the further improvement wherein
said operating means comprises said releasing means.
7. In a firearm as set forth in claim 6 the further improvement wherein
said first blocking member is supported on said secondary trigger for
movement between said blocking and releasing positions and said releasing
means comprises coengageable cam surfaces on said first blocking member
and said releasing means.
8. In a firearm as set forth in claim 7 the further improvement wherein
said first safety mechanism includes an abutment surface on said receiver
and said first blocking member in its blocking position is engageable with
said abutment surface.
9. In a retrofit firearm as set forth in claim 7 wherein said operating
means comprises an elongated operating member operably connected to said
primary trigger and extending in the direction of said secondary trigger
and supported within said retrofit housing for movement toward and away
from said secondary trigger in response to movement of the primary trigger
between its first and second positions the improvement comprising an
operating cam carried by said operating member and defining one of said
cam coengageable surfaces, said coengageable cam surfaces being in
coengagement during the initial portion of travel of said primary trigger
toward its second position, said one cam surface causing movement of said
secondary trigger toward its firing position during the remaining portion
of travel of said primary trigger to its second position.
10. In a retrofit firearm as set forth in claim 1 the further improvement
comprising second safety means for releasably securing said primary
trigger in a safe position to prevent movement of said primary trigger
toward its second position.
11. In a retrofit firearm as set forth in claim 10 the further improvement
wherein said retrofit housing includes a pistol grip associated with said
primary trigger and said second safety means comprises a grip safety
associated with said pistol grip.
12. In a retrofit firearm as set forth in claim 11 wherein said grip safety
includes a second blocking member, means for urging said second blocking
member toward a blocking position in the path of movement of said primary
trigger toward its second position, and a grip safety member supported on
said pistol grip for movement relative thereto between safe and released
positions and projecting from said pistol grip, said second blocking
member and said grip safety member having coengagable cam surfaces thereon
for moving said blocking member out of the path of the said primary
trigger in response to movement of said grip safety member to its released
position.
13. In a retrofit firearm as set forth in claim 10 the further improvement
including third safety means associated with said primary trigger for
releasably retaining said primary trigger in said first position.
14. In a retrofit firearm as set forth in claim 13 the further improvement
wherein said third safety means comprises a cross-bolt safety mechanism.
15. A retrofit firearm having a receiver, a firing mechanism contained
within said receiver, a secondary trigger supported on the receiver to
move between ready and firing positions for releasing said firing
mechanism in said firing position to discharge said firearm, a retrofit
housing containing at least a portion of said receiver, a primary trigger
supported on said retrofit housing in spaced relation to said secondary
trigger for movement between first and second positions corresponding
respectively to said ready and firing positions, operating means for
moving said secondary trigger to said firing position in response to
movement of said primary trigger toward said second position, and a first
safety mechanism associated with said secondary trigger including a first
blocking member supported for movement between blocking and releasing
positions, means for biasing said first blocking member toward said
blocking position, said first blocking member in said blocking position
preventing movement of said secondary trigger to said firing position, and
releasing means for moving said first blocking member from said blocking
position to said releasing position in response to movement of said
primary trigger toward its second position.
16. Combination as set forth in claim 15 wherein said operating means
comprises said releasing means.
17. The combination as set forth in claim 16 wherein said first blocking
member is supported on said secondary trigger and said operating means is
engageable with said first blocking member during initial movement of said
primary trigger from its first toward its second position to move said
blocking member from its blocking position to its releasing position.
18. In a retrofit firearm having essential operating elements of a basic
firearm and a retrofit assembly assembled with the essential operating
elements of the basic firearm, the essential operating elements including
a receiver, a barrel projecting forwardly from the receiver, and a firing
mechanism substantially contained within the receiver and including a
secondary trigger supported on the receiver for movement between ready and
firing positions corresponding respectively to ready and firing positions
of the firing mechanism and having an operating portion projecting from
the receiver, and a retrofit assembly including a retrofit housing
containing at least a portion of the receiver and said operating portion
of said secondary trigger, said retrofit assembly including a primary
trigger supported on said retrofit housing in spaced relation to said
secondary trigger for movement between first and second positions
corresponding respectively to said ready and firing positions of said
secondary trigger, and connecting means for operating said secondary
trigger to discharge said retrofit firearm in response to movement of said
primary trigger from its first to its second position, the improvement
comprising a first safety mechanism including a blocking cam pivotly
supported on said secondary trigger for movement between blocking and
releasing positions relative to said secondary trigger, said blocking cam
in said blocking position being disposed in blocking relation to an
associated abutment surface on said basic firearm to prevent movement of
said secondary trigger from its ready to its firing position, said
connecting means comprising an elongated connecting member operably
connected to said primary trigger and extending in the direction of said
secondary trigger, said connecting member being supported within said
retrofit housing for sliding movement generally toward and away from said
secondary trigger in response to movement of said primary trigger between
its first and second positions, said connecting member having an operating
cam for engaging said blocking cam during the initial portion of travel of
said primary trigger from its first position toward its second position to
move said blocking cam from said blocking position to said releasing
position, said operating cam being operably associated with the operating
portion of said secondary trigger during the remaining portion of travel
of said primary trigger from its first position to its second position
whereby to discharge said retrofit firearm.
19. In a retrofit firearm as set forth in claim 18 the further improvement
wherein said retrofit assembly includes means for urging said blocking cam
towards its blocking position.
20. In a retrofit firearm assembly as set forth in claim 19 the further
improvement wherein said urging means comprises means for biasing said
blocking cam toward and holding it in its blocking position when said
primary trigger is in its first position. |
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Claims |
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Description |
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BACKGROUND OF THE INVENTION
This invention relates in general to firearms and deals more particularly
with improvements in a retrofit firearm of the type which comprises a
proven basic firearm and a retrofit assembly which converts the basic
firearm to a firearm of another type without altering the operational
characteristics of the basic firearm.
The escalating incidence of suburban crime has created demand for improved
home security weapons. It is generally recognized that a shotgun is more
ideally suited than a handgun for use as a home defense weapon, because of
the probability of a first shot hit, even in the hands of a relatively
inexperienced person. The devastating effect of a shotgun at close range
is well known. Consequently, an intruder is not likely to attack when
confronted by a shotgun. Further, if it should be necessary to discharge
the weapon in self-defense within a building, it is unlikely that the
fired projectiles would retain sufficient velocity to kill or seriously
wound an innocent person after passing through a wall of the building.
The relatively great length of a conventional sporting shotgun makes it
difficult to handle at close range as a defense weapon. To overcome this
problem retrofit assemblies have been provided which convert a
conventional sporting shotgun to a weapon of military combat or battle
type more ideally suited for use at close range.
A retrofit firearm of the aforedescribed general type and which the present
invention is primarily concerned is illustrated and described in U.S. Pat.
No. 4,601,123 of Swearengen, et al, filed Jan. 10, 1984, and assigned to
O. F. Mossberg & Sons, Inc., North Haven, Conn., assignee of the present
application.
The retrofit firearm disclosed in the aforementioned application comprises
a basic sporting firearm or shotgun from which the stock has been removed.
The essential elements of the basic shotgun, and which comprise part of
the retrofit shotgun, include a receiver, which contains the gun operating
or firing mechanism, a barrel which projects from the receiver and a
trigger supported on the receiver for releasing the firing mechanism to
discharge the gun. At least a portion of the receiver of the basic shotgun
and its trigger are contained within a retrofit housing which comprises
part of the retrofit assembly. The retrofit housing substantially alters
the outward appearance of the basic sporting shotgun and imparts to it the
configuration of a combat weapon. The retrofit assembly further includes a
primary trigger and a trigger connector assembly which connects the
primary trigger, used to fire the retrofit shotgun, to the trigger on the
basic firearm, hereinafter referred to as the secondary trigger. Since the
manually operated safety mechanism or mechanisms on the basic firearm must
be disabled or removed before the retrofit housing is assembled on the
basic firearm, the required safety mechanism is incorporated in and
comprises part of the retrofit assembly. The present invention is
concerned with improvements in retrofit firearms of the aforedescribed
general type and more specifically with safety mechanisms for such
retrofit firearms.
SUMMARY OF THE INVENTION
In accordance with the present invention, a retrofit firearm comprises the
essential operating elements of a pre-existing basic firearm and a
retrofit assembly. The essential element of the basic firearm include a
receiver, a barrel projecting forwardly from the receiver, a firing
mechanism contained within the receiver and a secondary trigger supported
on the receiver for the movement between ready and firing positions to
discharge the basic firearm. The retrofit assembly includes a retrofit
housing which contains the secondary trigger and at least a portion of the
receiver. The retrofit assembly further includes a primary trigger
supported on the retrofit housing for movement between first and second
positions and a trigger connector assembly for moving the secondary
trigger from its ready to its firing position in response to movement of
the primary trigger from its first position toward its second position to
discharge the retrofit firearm. In accordance with the present invention,
the retrofit assembly further includes a first safety mechanism which has
a first blocking member associated with the secondary trigger and
supported for movement between blocking and releasing positions relative
to the secondary trigger. The first blocking member in its blocking
position prevents movement of the secondary trigger to its firing
position. The retrofit assembly also includes a releasing means for moving
the first blocking member from its blocking position to its releasing
position in response to movement of the primary trigger toward its second
position.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a right side elevational view of a typical retrofit firearm
embodying the present invention.
FIG. 2 is a longitudinal sectional view through the firearm shown in FIG.
1.
FIG. 3 is a somewhat enlarged fragmentary left side elevational view of the
firearm shown with a section of the retrofit housing removed therefrom.
FIG. 4 is a somewhat enlarged perspective view of the trigger connector
assembly.
FIG. 5 is a somewhat further enlarged fragmentary sectional view taken
along the line 5--5 of FIG. 3.
FIG. 6 is a somewhat enlarged fragmentary sectional view taken along the
line 6--6 of FIG. 5.
FIG. 7 is an enlarged fragmentary side elevational view similar to FIG. 3.
FIG. 8 is a fragmentary sectional view taken along the line 8--8 of FIG. 3.
FIG. 9 is a somewhat enlarged fragmentary sectional view taken generally
along the line 9--9 of FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to the drawings, a retrofit firearm or shotgun embodying the
present invention is indicated generally by the reference numeral 10 in
FIG. 1. The illustrated retrofit shotgun 10 essentially comprises a
thoroughly proven basic sporting shotgun, designated generally by the
numeral 12 and best shown in FIG. 2, from which the stock and forearm have
been removed. A retrofit assembly indicated generally at 14 and assembled
with the basic shotgun 12 converts the basic sporting shotgun to the
retrofit shotgun 10, which, as shown, is of combat or military type.
Referring further to FIG. 2 the retrofit assembly 14 essentially comprises
a retrofit housing, indicated generally at 16, and a forearm 18 which
replaces the sporting type forearm removed from the basic sporting shotgun
12. The retrofit assembly further includes a heat shield 20, a recoil beam
designated generally by the numeral 22 in FIG. 2, and a trigger connector
assembly or operating member, indicated generally at 24. Further, and in
accordance with the invention, the retrofit assembly also has a first
safety mechanism, indicated generally at 26, and second and third safety
mechanisms designated generally by the numerals 28 and 30, respectively.
The housing 16, forearm 18 and heat shield 20 cooperate in assembly with
each other to encapsulate a portion of the basic sporting shotgun 12
whereby to convert it from a shotgun of sporting length to a combat or
military type shotgun of somewhat shorter length, more ideally suited for
use as a defense or close assault weapon. The conversion is made without
altering the operational characteristics of the proven sporting shotgun or
requiring modification of the basic gun other than the simple elimination
of parts.
The illustrated basic sporting shotgun 12 comprises a MOSSBERG 500 slide
action shotgun manufactured and marketed by O. F. Mossberg & Sons, Inc.,
North Haven, Conn. 06473, and has a receiver 32 which includes an integral
trigger guard 34 near its rear or stock end. A rectangular ejection port
36 opens through the right-hand wall of the receiver and a rectangular
loading opening is formed in the bottom wall of the receiver forward of
the trigger guard 34, but not shown, through which shells are loaded into
the shotgun 12 in a manner well known in the art. A barrel 38 threadably
connected to the receiver 33 projects forwardly from it and may be
provided in various lengths and choke combinations.
The illustrated basic sporting shotgun 12 further includes a magazine tube
40 which extends forwardly from the receiver below and in parallel
relation to the barrel 38. An action slide assembly, indicated generally
at 42 in FIG. 2, includes a slide tube 44 slidably supported on the
magazine tube 40 and a pair of action bars 46,46 (one shown) which extend
rearwardly from the slide tube at opposite sides of the magazine tube and
into the receiver 32 for moving a conventional bolt (not shown) contained
within the receiver to and from battery position. The forward end of the
slide tube 42 is threaded to receive a slide tube nut 48 which usually
retains the sporting forearm in assembly with the slide tube 44. However,
in the retrofit shotgun 10 the nut 38 is used to retain the forearm 18 in
fixed position on the slide tube to move with it. A conventional firing
mechanism contained within the receiver 32 is released to discharge the
firearm 10 by a shotgun trigger 50, pivotly supported on the receiver and
exposed within the trigger guard 34. In the further description which
follows and in the claims the shotgun trigger 50 is referred to as the
secondary trigger to clearly distinguish it from a primary trigger which
forms a part of the retrofit assembly hereinafter more fully described.
The retrofit housing 16 and forearm 18 which surround the shotgun action
are preferably molded from durable high-impact plastic materials to resist
severe punishment. Preferably, and as shown, the retrofit housing 16
comprises a hollow clam shell housing formed by two mating housing
sections 52,52' of opposite hand (one shown in FIG. 2) and a cup-shaped
butt plate 54. The D housing sections 52,52' cooperate in assembly to
generally compliment associated portions of the receiver 32 received
therein and also contain at least portions of the barrel 38, magazine tube
40 and action slide assembly 42.
A detailed description of the manner in which the sections of the retrofit
housing 16, the heat shield 20 and the recoil beam 22 are assembled with a
basic sporting shotgun is found in U.S. Pat. No. 4,601,123 of Swearengen,
et al which is hereby adopted by reference as part of the present
disclosure. Only those details of the retrofit assembly essential to the
further understanding of the invention will be hereinafter discussed.
The retrofit housing 16 has a relatively short stock portion which contains
a major portion of the receiver 32, the trigger guard 24 and the secondary
trigger 50. The retrofit housing 16 also defines a pistol grip 56 and an
associated trigger guard 58.
Referring now more particularly to FIG. 3, the primary trigger indicated by
the numeral 60 is supported within recesses in the trigger guard formed by
the mating sections of the retrofit housing 16 for forward and rearward
sliding movement between first and second positions, indicated in full and
broken lines in FIG. 3, corresponding, respectively, to ready and firing
positions of the secondary trigger 50. The trigger connector assembly 24
operably connects the primary trigger 60 to the secondary trigger 50 and
moves the secondary trigger to firing position in response to movement of
the primary trigger 60 rearwardly toward the stock portion of the housing
16, and toward its second position.
In accordance with the present invention, the first safety mechanism 26
prevents movement of the secondary trigger 50 toward its firing position
when the primary trigger 60 is in its first position, that is the position
corresponding to the ready position of the secondary trigger 50. The first
safety mechanism 26 comprises a first blocking member or blocking cam 62
pivotly supported within a slot in the secondary trigger 50 by a blocking
cam pivot pin 64 for movement between blocking and releasing positions
relatively to the secondary trigger 50 and indicated by full and broken
lines, respectively, in FIG. 7. The trigger blocking cam 62 is biased
toward and held in its blocking position by a trigger cam spring 66 which
acts between the secondary trigger 50 and the trigger blocking cam 62. In
the blocking position a projection 68 on the blocking cam 62 engages an
associated portion of an abutment surface defined by the inner surface of
trigger guard 58 to prevent rearward movement of the secondary trigger 60
from its ready position toward its firing position.
In addition to operating the secondary trigger 50 the primary trigger 60
and its associated trigger connector assembly 24 also serve to release the
first safety mechanism 26 to enable operation of the secondary trigger 50,
as will be hereinafter further discussed. The trigger connector assembly
24 is formed by a pair of elongated right and left side trigger connector
brackets 76,76 connected together at the forward ends thereof by a
spreader 78, which has a downwardly bent forward end portion 79. The end
portion 79 has a notch 81 (FIG. 8) to engage the rear end portion of a
trigger pin 80 connected in fixed position to the primary trigger 60 by a
trigger pin retaining screw 82, as shown in FIG. 3. The rear end portions
of the trigger connector brackets 76,76 are joined together by a roller
cam 84 journalled on the brackets for rotation about an axis extending in
a transverse direction relative to the axis of the barrel 38. The roller
cam 84 is disposed in close relationship with the blocking cam 62 when the
primary trigger 60 is in its first position. A trigger return spring 86
received on the trigger pin 80 between a pair of trigger pin washers 88,88
acts between the primary trigger 60 and forwardly facing abutment surface
90 on the retrofit housing 16 to urge the primary trigger 60 in a forward
direction and to its first position which corresponds to a ready position
of the secondary trigger 50.
Movement of the primary trigger 60 in rearward direction or toward its
second position, indicated by broken lines in FIG. 3, in opposition to the
biasing force of the trigger return spring 86 causes corresponding
rearward movement of the roller cam 84. Initial rearward movement of the
primary trigger 60 brings the roller cam 84 into camming engagement with
the blocking cam 62 supported on the secondary trigger and cams the
blocking cam to its releasing or broken line position of FIG. 7. Further
rearward movement of the primary trigger 60 toward its second position
causes the roller cam 84 to move the secondary trigger 50 toward and to
its firing position whereby the retrofit firearm 10 is discharged.
Upon release, the primary trigger 60 is returned to its first position in
response to the biasing force of the trigger return spring 86. The
secondary trigger 50 is returned to its ready position by a return spring
or other biasing means associated with the firing mechanism and located
within the receiver 32, but not shown. The blocking cam 62 also returns to
its blocking position in response to the biasing force of the trigger cam
spring 66 where it is held by the latter spring until such time as the
firearm is again discharged by operation of the primary trigger 60.
The second safety mechanism 28 comprises a grip safety mechanism which
functions to releasably retain the primary trigger 60 in its first
position until gripping pressure is applied to the pistol grip 56, as when
the gun is held in a firing position. Referring now particularly to FIGS.
3, 5, and 6, the second safety mechanism or pistol grip safety 28
comprises a second blocking member 92 disposed within a generally
complimentary recess in the retrofit housing above the pistol grip 56
generally rearward of the primary trigger 60 and a safety grip member 94
received within another portion of the latter recess and having an
operating portion which extends rearwardly through and beyond the pistol
grip. The grip safety member 94 is biased in a rearward direction to
project from the pistol grip 56 by a safety grip spring 70 which acts
between the grip safety member 94 and the primary trigger 60. A safety
grip pin 72 extends into the spring 70 and is retained in fixed position
on the primary trigger 60 by a retaining screw 74, as shown in FIGS. 3 and
5.
The second blocking member 92 is biased toward a blocking position rearward
of the primary trigger 60 by a trigger blocking spring 96 which urges the
blocking member in a lateral direction and toward its blocking or full
line position of FIG. 5. Coengagable cam surfaces 98 and 100 on the second
blocking member 92 and the safety grip member 94 cause lateral movement of
the second blocking member 92 to a released position out of the path of
rearward movement of the primary trigger 60 when the grip safety member 94
is depressed into the pistol grip 56 by grasping the pistol grip, as when
the gun is held in its usual firing position.
The third safety mechanism 30 comprises a cross bolt safety mechanism of
conventional type located in the forward portion of the trigger guard 58.
The cross bolt safety mechanism has a cross bolt safety member 102, best
shown in FIGS. 3 and 9, which extends transversely through the trigger
guard 58 and cooperates with a forwardly projecting trigger extension 104
connected in fixed position to and extending forwardly from the primary
trigger 60. The trigger extension 106 moves with the primary trigger 60
and within an associated complimentary slot formed in the upper part of
the trigger guard 58.
In its "on" or safety position the cross bolt safety member 102 is disposed
in blocking relation to the trigger extension 104 and prevents rearward
movement of the primary trigger 60 from its first toward its second
position. Lateral movement of the cross bolt safety relative to the
trigger guard 58 and to its "off" or released position aligns a slot 106
formed in the cross bolt member 102 with the forward end of the trigger
extension 104 to allow the trigger extension and the primary trigger 60
connected to it to move freely and in a rearward direction or toward the
second position of the primary trigger 60 whereby to discharge the
firearm. A cross bolt safety spring 108 disposed within an associated
recess in the trigger guard 58 exerts biasing force on the cross bolt
safety member 102 to frictionally retain it in one of its positions until
it is manually moved to the other of its positions. Thus, the illustrated
retrofit firearm 10 includes three separate and distinct safety mechanisms
to prevent accidental firing.
To fire the weapon 10 the cross bolt safety member 102 must first be
manually moved to its "off" or released position to release the primary
trigger 60 from its positively blocked position. The pistol grip 56 must
also be manually grasped to depress the grip safety member 94 which moves
the second blocking member 92 laterally and out of blocking relation to
the primary trigger 60. The primary trigger must also be moved from its
first position toward its second position and through a sufficient
distance to release of the secondary trigger blocking cam 62 from its
blocking position and to move the secondary trigger 50 from its ready
position to its firing position.
After the weapon has been fired and the primary trigger is returned to its
first position by the trigger return spring 86. The trigger blocking cam
62 associated with the secondary trigger 50 automatically moves to its
blocking or safe position so that the firearm cannot be discharged again
until the primary trigger 60 is moved to its second position. Upon release
of the pistol grip 56 the second safety mechanism 28 automatically moves
to its safe or blocking position relative to the primary trigger 60. Thus,
the first and second safety mechanisms 26 and 28 operate automatically and
substantially independently of each other to safeguard against accidental
firearm discharge. The third safety mechanism 30 which positively blocks
the primary trigger 60 should, of course, be manually positioned in its on
or "safe" position except when the weapon is to be intentionally fired.
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