Note: Descriptions are shown in the official language in which they were submitted.
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MOZZLE LOADING WEAPON IGNITION SYSTEM
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates generally to rifles, and
more particularly to a muzzle loading rifle with an improved
ignition system.
State of the Prior Art
Hunting with muzzle loading rifles has become
increasingly popular in the last few years. Many hunters
prefer to use muzzle loading rifles because a game animal
has a greater chance to escape with its life, thus the
hunter's skill can be more adequately tested. Some hunters
also enjoy the muzzle loading routine of pouring powder down
the rifle barrel, packing it, and driving a shot down the
barrel. Some states even have a separate hunting season for
sportsmen with muzzle loading firearms.
Hunting with muzzle loading rifles presents
several additional challenges. Most muzzle loading weapons
used by hunters fire by means of a cup shaped percussion cap
which contains a small explosive charge ignitable upon
application of a sufficient impact. The percussion cap is
placed over a nipple. A passage way through the nipple and
into the barrel of the weapon passes the hot gasses produced
when the percussion cap is ignited. Typically the muzzle
loading hunting season occurs at a time of the year when the
weather is cold and inclement. Percussion caps are well
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known for being an unreliable ignition source in such
weather. They absorb moisture and may become waterlogged
and unusable. Also, they contain only a small charge. A
further inconvenience of percussion caps becomes apparent
when a hunter attempts to remove a spent cap from the nipple
in the field. Sometimes the cap is very difficult to pry
off of the nipple, especially with cold fingers.
To overcome the inadequacies of percussion caps as
an ignition source, some gun designers employ shot gun shell
primers as an ignition source. Shot gun shell primers are
primarily used as the ignition source for shotgun shells for
regular breech loading shotguns, but make an excellent
ignition source for a muzzle loading weapon. They comprise
a tubular metal casing, an annular flange at one end of the
casing and extending outwardly radially therefrom, a charge
of explosive material, and a hole at the opposite end from
the flange for expelling the hot gasses from the explosion.
Shot gun shell primers are much less susceptible
to the ravages of damp weather and rarely become water
logged unless immersed in water. Shot gun shell primers
also contain a much larger charge of explosive material for
a more reliable ignition of the black powder charge.
However, previous ignition systems for muzzle loading
weapons designed to use shot gun shell primers as an
ignition source require that the primer be inserted axially
(in the direction that the hot ignition gasses will escape)
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''- into a tight fitting well until the annular flange prevents
the primer from being inserted further. The primer must fit
snugly into the well to prevent it from falling out. Many
times gasses and ash blowing back into the ignition system
from the exploding black powder charge dirties the well.
When this happens, the primer is very difficult to insert
and remove. Even when the well is relatively clean the
primer is difficult to remove with cold hands.
A second problem with muzzle loading weapons is
accuracy. One element of inaccuracy is a relatively long
lock time compared with conventional breech loading weapons.
Lock time is measured from the time the trigger is squeezed
until the black powder charge launching the bullet actually
fires. Many muzzle loading weapons employ a traditional
swing hammer mounted on the side of the barrel, which swings
through an arc and strikes a percussion cap. The hot gasses
from the cap must travel a long, and sometimes circuitous
path, into the barrel before igniting the black powder
charge. Also, if only the side of the charge is ignited it
may not burn evenly. The longer the lock time, the longer
the shooter has to hold the rifle steady and on target.
Even very small delays can cause inaccuracies due to the
physical inability of even the best shooters to hold the
weapon completely still. Small movements of the rifle
greatly affect the bullet's path.
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To reduce lock time it is desireable to have a
fast hammer and a short direct path from the ignition source
into the black powder charge. Recently in-line firing
systems have gained some popularity for their inherently
faster lock times, thus higher accuracies. The firing
mechanism and ignition source are lined up immediately
behind the black powder charge to reduce the distance the
hammer has to travel and also the distance that the hot
gasses have to travel. The gasses enter the barrel axially
to reduce uneven burning of the black powder charge. If
used with a shot gun shell primer, lock time may be further
reduced by providing a hotter spark to more quickly ignite
the black powder charge.
A drawback of such systems is the awkward
placement of the percussion cap nipple or primer well inside
the barrel. Typically they are accessed through an opening
in the side of the barrel. Access is difficult because of
the small space for putting one's fingers. In cold weather,
access is even more difficult due to the limited mobility of
cold fingers.
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SUMMARY OF THE INVENTION
The present invention overcomes the disadvantages
of difficult loading and removal of primers, making them a
practical ignition source for in-line or other firing
systems. It provides an easy method of inserting and
removing shot gun shell primers; the well is sized to
receive the primer loosely to prevent sticking, and accepts
the primer from the side for easier loading. Conventional
swing hammer weapons may also benefit from the easy loading
and improved reliability of the present invention. The
ignition system is suitable for retrofit to existing weapons
or as original equipment in new weapons.
An ignition mechanism, according to the invention,
is provided for use in a muzzle loading firearm having a
barrel bore and a firing pin. The mechanism comprises a
body having at least one wall partially defining a receiving
chamber. The wall separates opposing ends of the receiving
chamber and has a loading slot. The body has a spark port
extending from one end of the receiving chamber through the
body. Firing means on the body at the other end of the
receiving chamber facilitate ignition of a primer charge by
the firing pin when the receiving chamber is loaded. The
body is further configured to be mounted to the firearm with
the spark port in communication with the barrel bore, and a
cover is mounted to the body in a position to cover the
loading slot.
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The cover can be rotatable about a central axis of
the body, and the rotation may be by means of mating threads
on the cover and the body. The threads on the cover and
body may be oriented so that when the cover is closed with
the primer charge inside the ignition mechanism, friction
thereby developed in the threads will tend to keep the cover
closed.
The cover can have an opening whereby when the
loading slot and opening are in register, the primer charge
may be inserted into the chamber. The cover may be
configured so that when the primer slot and opening are out
of register, the primer charge is held securely within the
chamber.
The chamber can have a circular cross section.
Typically, the primer charge comprises a cylindrical casing
enclosing an explosive charge. An annular flange at one end
extends outwardly radially from the casing, and an opening
is provided at the opposite end for expelling hot gasses
produced when the explosive charge is ignited. The chamber
is sized to loosely receive the primer charge casing. The
chamber further comprises an annular edge, formed at the
opposite end from the spark port, which receives the annular
flange on the primer charge casing. The primer slot
interrupts the annular edge. The cover can be rotatable
about the body by means of mating threads on the cover and
the body.
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Preferably, the ignition mechanism is constructed
so that the spark port is coaxial with the bore of the
barrel. The primer charge for the ignition mechanism
typically comprises a shotgun shell primer.
In another aspect of the invention, a muzzle
loading weapon comprises a barrel having an axial bore and
an ignition system. The ignition system comprises a body
having a chamber for holding an impact ignitable ignition
source. The ignition source has a casing, and an explosive
charge within the casing. The ignition source is ignitable
by means of an impact against its exterior thereby expelling
a stream of hot gases through a breach in the casing. The
stream of hot gases defines a first direction. A first
opening in the chamber is sized and oriented to closely pass
the ignition source into the chamber in a second direction
which is different from the first direction. A cover is
provided for covering the first opening and holding the
ignition source within the chamber.
The cover is preferably rotatable about a central
axis of the ignition system in the first direction. The
cover can have a second opening whereby when the first
opening and second opening are in register, the ignition
source may be inserted into the ignition system through the
openings. The cover can be constructed so that when the
first and second openings are out of register, the ignition
source is held securely within the ignition system.
' '
The cover comprises a hollow cylindrical section
with a wall at a first end and which is open at an opposite
second ends the chamber of the body being coaxially received
within the cover through its second end. The wall of the
cover further comprises a hole for passing a firing pin of
the weapon for impacting and igniting the ignition source.
Typically, the barrel of the weapon has an
internal threaded section and the body has an external
threaded section adapted to mate with the internal threaded
section.
In a method for loading a shotgun shell primer
into an ignition system of a muzzle loading weapon as an
ignition source for the weapon, wherein the primer comprises
a casing containing an charge which explodes and expels hot
gasses from a portion thereof when struck with a sufficient
force; the method comprises: inserting the primer into the
ignition system through a first opening in a direction
substantially different from the direction which the hot
gasses exit the primer; covering the first opening to hold
the primer within the ignition system in preparation for
ignition. The method can further comprise aligning a second
opening in a rotatable cover with the first opening before
inserting the primer and the first opening can be covered by
rotating the cover until the first and second openings are
no longer in alignment.
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A holder for spare primers according to the
invention comprises a semicircular ring of elastomeric
material adapted to snap onto a rifle sighting scope, and
holes through the ring for receiving a primer and sized to
hold the primer by friction.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described with reference
to the accompanying drawings in which:
FIG. 1 is a perspective view of an in line firing
muzzle loading rifle incorporating an ignition system
according to the invention:
FIG. 2 is a close up perspective view of the
ignition system of FIG. 1, without the breech plug;
FIG. 3 is an exploded partial sectional side view
of the ignition system of FIG. 1:
FIG. 4 is an exploded partial sectional side view
of an alternative embodiment of an ignition system according
to the invention;
FIG. 5 is a side view of a conventional swing
hammer type muzzle loading rifle incorporating the ignition
system of FIG. 1;
FIG. 5A is a side view of a conventional swing
hammer type muzzle loading rifle incorporating an
alternative embodiment of an ignition system according to
the invention: and
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FIG. 6 is a perspective view of a primer holder
according to the invention.
DETAILED DESCRIPTION OF THE DRAWINGS
Referring now to the drawings, FIG. 1 shows a
muzzle loading rifle l0 incorporating an ignition system 12
according to the present invention. The rifle 10 comprises
a barrel 14 having a rear or breech end 16 and a forward end
18 and a bore 20 therethrough. A bolt 22 is axially aligned
with the bore 20 of the barrel and extends into the bore 20
from the breech end 16 of the barrel 14. The bolt 22 is
spring loaded and enable the gun 10 to be fired in a
conventional manner. The U.S. Patent No. 4,700,499 to
Knight issued October 20, 1987, more fully illustrates the
structure and operation of a conventional in line firing
bolt such as that illustrated at 22.
The muzzle loading rifle 10 incorporates a breech
plug 24 near the breech end 16 of the barrel 14. An opening
26 through the side of the barrel 14, to the rear of the
breech plug 24, provides access to the ignition system 12.
When the rifle 10 is loaded, a charge of black powder,
wadding and shot (not shown) sits in the bore 20 of the
barrel 14 just forward of and against the breech plug 24.
As seen in FIG. 3, the breech plug 24 is
cylindrical and has threads 28 on its outer surface which
engage corresponding threads in the bore of the barrel 20
(not shown). A central bore 30 passes axially through the
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breech plug 24 and is generally coaxial with the bore of the
barrel 20 (not shown in FIG. 3), when the breech plug 24 is
installed therein. An intermediate threaded bore 32 is
countersunk into the rear end of the breech plug 24 and is
coaxial with the breech plug central bore 30. An outer bore
34 is countersunk into bore 32, is not threaded, has a
somewhat larger diameter than bore 32, and is generally
coaxial to the intermediate and central bores 32 and 30.
In prior art weapons, a percussion cap nipple (not
shown) would be screwed into the intermediate bore 32 and
adapted to receive a cup shaped percussion cap (not shown).
The conventional percussion cap nipple for an in-line fired
rifle 10, has a central bore axially aligned with the breech
plug central bore 30. The gun 10 was fired when the bolt 22
struck and ignited the percussion cap. Hot gasses from the
percussion cap traveled through nipple, the central bore 30
of the breech plug 24 and into the charge of black powder in
the barrel 14 of the rifle 10. The ignition system 12 of
the present invention is adapted to replace the percussion
cap nipple.
Turning now to FIGS. 2 and 3, the ignition system
12 is adapted to use a standard shotgun shell primer 36 as
an ignition source in place of a percussion cap. An example
of a suitable primer 36 is a Model 209 type primer
commercially available from Remington Arms Company, Inc.,
Bridgeport, Connecticut. The shotgun shell primer 36
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\' comprises a cylindrical casing 53 having an annular flange
54 at one end which extends outwardly radially from the
casing 53 of the primer 36. Shotgun shell primers 36 are
much more reliable ignition sources than standard percussion
caps they carry a larger charge and are better sealed from
the environment. The first embodiment of the ignition
system 12 according to the invention is adapted to replace
the percussion cap nipple in an existing weapon so that it
may be fired by means of the shotgun shell primer 36.
The ignition system 12 broadly comprises a
cylindrical body 38, a coaxial rotatable cover 40 mounted
thereon, and a locking collar 42 threaded onto the body 38.
As more clearly seen in FIG. 3, the body 38 comprises a
cylindrical threaded shank 44 at its forward end, adapted to
screw into the threaded intermediate bore 32 of the breech
plug 24 in place of the percussion cap nipple. A central
bore 46 passes coaxially through almost the entire length of
the body 38 and terminates to form a wall 48 at the front
end of the body 38. A narrower bore 50, coaxial with the
central bore 46, penetrates the wall 48 and connects with
the central bore 46. A primer chamber 52 for receiving the
shotgun shell primer 36 is located at the breech end of the
body 38.
The primer chamber 52 comprises a countersunk well
coaxial with the bore of the barrel 20 and adapted to
receive a shotgun shell primer 36. The primer chamber 52
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receives the casing 53 of the primer 36. The rear end of
the body 38 with the primer chamber 52 bored therethrough,
forms an annular edge 56 for receiving the annular flange 54
of the primer 36. A primer shaped cutout 58 in the wall of
the primer chamber 52 allows the primer 36 to pass radially
into the primer chamber 52. The cutout 58 interrupts the
annular edge 56 and extends axially therefrom for the full
length of the primer chamber 52 bore. A smaller cutout 60
interrupts the annular edge 56 opposite the primer cutout
58. The smaller cutout 60 allows some of the blow back
gasses from the exploding black powder charge to escape, and
also can receive a tool for installing the body 38 into the
rifle 10. A threaded section 62 of the outer surface of the
body 34, between the shank 44 and the primer chamber 52,
receives the cover 40.
The cover 40 is tubular having a circular cross
section and is closed at one end by a bulkhead 64. Internal
threads 66 at the open end engage the threads 62 on the body
34. The cover 40 screws onto the body 34 such that the
primer chamber 52 in the body 34 is received and enclosed
within the cover 40. A primer shaped cutout 68 in the side
of the cover 40 adjacent the bulkhead 64 is sized to pass
the casing 53 of the primer 36. A transverse slot 70 in the
body 40, immediately adjacent the bulkhead and connected to
the cutout 68 passes the flange 54 of the primer 36. The
slot 70 can be cut slightly longer than necessary to pass
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the flange 54, to provide a larger escape passage for blow
back gases produced by the exploding black powder charge.
An opening 72 through the center of the bulkhead
64 allows a firing pin 23, on the forward end of the bolt
22, to pass into the cover 40 for striking the primer 36 to
fire the gun 10. Parallel flats 74 cut as chords partially
into opposite sides of the outer surface of the bulkhead 64
provide a gripping surface for a tool to unscrew the cover
40 from the body 38. A lever 76 can be provided for easier
rotation of the cover 40 about the body 38. The lever 76
should be removable so that the cover 40 can be inserted
into the barrel 14 through the breech end 16. Preferably,
the lever has a cylindrical shape and threads 78 on one end
which thread into a threaded hole 80 on the cover to
removably attach the lever 76 to the cover 40.
The invention is not limited to covers which
rotate by means of screw threads, and many variations are
possible. For instance, the cover may rotate and have no
axial component to its movement. Non-rotatable covers may
also be employed. For instance the cover may slide over the
primer cutout 58 in the axial direction. However, the
rotatable cover 40 shown in FIGS. 1-3 is preferred for its
simplicity and ease of operation.
The locking collar 42 fixes the orientation of the
body 38 with respect to the breech plug 24. The locking
collar 42 comprises a threaded circular nut which screws
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~' onto the threads 62 on the body 38. Parallel flats 82 cut
as chords partially into opposite sides of one face of the
collar 42 provide a gripping surface for a tool to adjust
the collar 42 on the body 38. The outer surfaces of both
the cover 40 and the collar 42 may be knurled to ease
adjustment.
The ignition system 12 is installed in the rifle
through the breech end 16 of the barrel 14 with the bolt
22 removed. First, the locking collar 42 is placed on the
10 body 38 and the threaded shank 44 of the body 38 is screwed
almost entirely into the threaded bore 32 of the breech plug
24. A portion of the body 38 will then be inside the outer
bore 34 of the breech plug 24. The final position of the
body 38 in the breech plug 24 is set by orienting the primer
cutout 58 so that it faces out through the side opening 26
in the barrel 14. The locking collar 42 is then tightened
against the breech plug 24 to lock the position of the body
38 in the breech plug 24. Finally, the cover 40 is screwed
onto the body 38, and the lever 76 is screwed into the cover
40.
When properly adjusted, primer cutout 58 in the
primer chamber 52 of the body 38 faces outwardly through the
side opening 26. When the cutout 68 in the cover 40 is
aligned with the cutout 58 in the body 38, the primer 36 may
be radially inserted into the primer chamber 52 through the
aligned cutouts 58, 68. The cover 40 is then rotated by
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means of the lever 76 to enclose the primer 36 securely
within the primer chamber 52. The threads on the cover 66
and the threads on the body 62 should be oriented so that
when a primer 36 is in the primer chamber 52 and the cover
40 is rotated closed, the bulkhead 64 on the cover 40
contacts the flange 54 of the primer 36 and snugs the primer
36 into the primer chamber 52, to frictionally hold the
cover 40 closed.
After the rifle 10 is fired, the cover 40 is
opened and the primer 36 can fall out. The lever 76 is
preferably located on the body 38 such that when it is
pushed upwards to open the cover 40, the lever 76 contacts
the upper edge of the opening 26 and stops, leaving the
cutouts 58, 68 aligned. Sufficient clearance is provided
between the primer casing 53 and the walls of the primer
chamber 52 to allow the primer 36 to easily fall out, even
when the rifle 10 has been repeatedly fired causing a slight
build up of residue in the ignition system 12.
FIG. 4 shows an alternative embodiment of the
ignition system 12 according to the invention. It is
equivalent in all respects to the first embodiment of the
ignition system shown in FIGS. 1-3, with the exception that
the body 38 of the ignition system 12 is integral with the
breech plug 24. Whereas the first embodiment is primarily
intended as a retrofit for rifles originally using a
percussion cap nipple, the alternative embodiment of FIG. 4
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is primarily intended for use in rifles incorporating the
radially loading ignition system 12 as original equipment.
The breech plug 24 and body 38 are combined to
form a breech plug-body 84. The breech plug-body 84
comprises a threaded plug section 86 for screwing into the
threads (not shown) in the bore of the gun barrel 20, and a
narrower diameter body section 88. The body section 88
comprises the primer chamber 52, and the threads 62 for
receiving the cover 40. A central plug-body bore 90
provides a passage for the hot ignition gasses from the
primer 36 to the charge of black powder in the bore of the
barrel 20 forward of the breech plug-body 84. The plug-
body bore 90 can be narrowed at the forward end of the
breech plug-body 84, thus limiting the amount of blow back
gasses from the exploding black powder charge which enter
the ignition system 12, yet still allowing a large passage
over most of the ignition gas's path to reduce clogging.
The threads 28 on the plug section 88 should be cut so that
when the breech plug-body 84 is fully screwed into the
barrel 14, the primer cutout 58 is facing out of the side
opening 26 of the rifle barrel 14. Thus, the need for the
adjusting collar 42 is eliminated.
FIG. 5 shows an alternative use for the first
embodiment of the ignition system 12. Although the
preferred use of the ignition system 12 is in an in-line
firing muzzle loading rifle, it is also appropriate for use
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in a conventional swing hammer muzzle loading rifle. The
ignition system 12 replaces the percussion cap nipple (not
shown). The shank 44 of the body 38 screws into a threaded
hole 92 which originally received the percussion cap nipple.
The adjusting collar 42 adjusts the position of the primer
cutout 58 to a convenient position. The rifle 10 is fired
by means of a rotatable swing hammer 94 having a firing pin
96 which extends into the ignition system 12 when the rifle
is fired to ignite the primer 36. Alternatively, as
10 illustrated in FIG. 5A, a firing pin 200 can be incorporated
into the ignition system 12 by mounting the firing pin 200
in the hole 72 in the cover 40 and biasing the pin 200
outwardly of the ignition system 12 by means of a spring
202. When used to retrofit an existing swing hammer
percussion nipple ignition system, this allows use of the
original swing hammer 94 without modification.
To store extra primers 36, a primer holder 100 is
proposed for mounting onto an appropriate curved surface of
the rifle 10 such as a conventional rifle scope 102 as shown
in FIG. 6, or alternatively the barrel 14, or a stock of the
rifle 10. The primer holder 100 comprises a semi-circular
ring 104 of elastomeric material having a central radial rib
106 extending outwardly radially therefrom. The ring 104 is
adapted to fit the contour of its intended mounting
location. The rib has 106 faces 108, 110 and an outer
radial edge 112. Semi-circular holes 114, sized to receive
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primers 36, are drilled normal to the faces 108, 110 of the
rib 106, and preferably interrupt the radial edge of the rib
112 so that the primers 36 can be inserted into the holes
114 radially. The primer holder 100 is preferably formed of
urethane, 90 compression, or other suitable elastomeric
material so that the holder 100 may be snapped onto the
scope 102 yet firmly retained.
Reasonable variation and modification are possible
within the scope of the foregoing disclosure and drawings
without departing from the spirit of the invention, as
defined in the accompanying claims. For instance, the
ignition system 12 could be adapted to hold a standard rifle
cartridge primer or a standard percussion cap.
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