Note: Descriptions are shown in the official language in which they were submitted.
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101 -,
PORTABLE TUBULAR MAGAZINE FOR
SHOTGUN OR RIFLE
TECHNICAL FIELD
This invention relates to shotguns or rifles which are
fitted with a tubular magazine as a means of holding
cartridges in end to end alignment beneath the barrel in
r@adin~ss Eor being cycled into the Eiring chamber or for
being removed if they are unused.
BACKGROUND ART
Traditionally cartridges have been loaded into the
tubular magazine of a shotgun or rifle singly through a
loading aperture on the side or on the bottom of the
receiver. They can then be transferred to the firing
chamber and ejected after being fired. Unfired
cartridges can be removed from the tubular magazine by
being cycled through the firing chamber or, in some
cases, by being released through the loading aperture in
which case the firing chamber is by-passed. In both cases
unfired cartridges are ejected onto the ground unless
they are caught by hand as they are being ejected. Spare
cartridges are carried loose in boxes or pouches or they
are carried sometimes in belt loops.
.
DISCLOSURE
This invention eliminates the need to handle loose
cartridges while the tubular magazine of a shotgun or
rifle is being loaded or unloaded and it provides a
means of loading or unloading a full charge of
cartridges in one simple operation. This is made possible
by the utilization of a portable tubular magazine in
"conjunction with a guide tube, fore end and locking
assembly. The locking assembly allows the portable
~`30 tubular magazine to be locked inside the guide tube in
two positions to provide a degree of safety not found in
firearms fitted with conventional fixed tubular
magazines. When locked in the first position no
cartridges can be released from the portable tubular
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magazine even when the action is cycled.
Cartridges can be loaded into or removed from a portable
tubular magazine when it is separated from the firearm or
when it is locked inside the guide tube which is
connected to the firearm's receiver in place of it's
conventional, Eixed, tubular magazine. When the portable
tubular magazine is locked inside the guide tube
cartridges can be loaded or unloaded in the conventional
manner or, alternatively, a portable tubular magazine,
with or without car~ridges, can be inserted into or can
be removed from the guide tube at any time.
A portable tubular magazine consists of a rigid steel
tube haviny a threaded end cap at one end and a tapered
or crimped opening at the other which serves to contain
within the portable tubular magazine a cartridge pusher
and a magazine spring.
On the bottom center line inside the portable tubular
magazine near the open end a short steel retaining pin
blocks the exit of any cartridges which have been
inserted. The rear face of this cartridge retainer is
beveled so that it can be deflected by cartridges as they
are being inserted. To ensure that this bevel always
faces the rear a square stem on the other end of the
cartridge retainer is made to fit through a square hole
in the end of the housing which contains it. Also
contained within this housing is a compression spring
which keeps the cartridge retainer in the extended
- position. To release cartridges from the portable tubular
magazine the cartridge retainer is retracted by raising a
button-shaped lifter connected to the cartridge retainer
stem outside of the housing.
Cartridges are held inside the portable tubular magazine
~between the cartridge retainer and the cartridge pusher
;~which, being slightly larger in diameter than a
~35 cartridge, cannot be pushed by the magazine spring
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103
through the tapered or crimped open end. The cup-shaped
cartridge pusher fits over the back end of the magazine
spring and to ensure that cartridges can be pushed
Completely out of the portable tubular magazine the rear
face of the cartridge pusher can be stepped down to a
smaller diameter and made longer to suit the taper or
crimp at the open end.
A small steel lock ring encircles the portable tubular
magazine towards it's front end and when the portable
tubular magazine is fully seated within the guide tube
the ring is held against the mouth of the guide tube by
the second of two beveled teeth on spring-loaded lock
levers.
Flat sides are machined onto the end cap on two sides and
the bottom while the top side is left rounded. The shape
of the end cap is an aid in determining when the vertical
axis of the portable tubular magazine is in proper
perpendicular alignment for inserting the portable
tubular magazine into the guide tube.
The front end of the rigid steel guide tube is flared
slightly to ease the entry of the portable tubular
magazine and the other end is fitted with a connector
which matches the connector socket of the receiver to
which it is to be attached. The length of the guide tube
is such that the free operation of the sliding fore end
it supports is not hindered and ample space is provided
`to mount the barrel clamp and the lock levers. The
underside of the guide tube is slotted to provide a
channel for the cartridge retainer housing and
-~30 lifter. This slot~e~xtends backwards from the front end of
the guide tube to a point just in front of the receiver
`connector. Steel wedges tapered toward the front are
fitted one on each side of the slot at the back end to
form a ramp up which the lifter rides to retract the
cartridge retainer when the portable tubular magazine is
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104
fully seated within the guide tube. Slots or notches on
the t~o sides of the guide tube flare form openings
through which the lock levers engage the lock ring on the
portable tubular magazine. The two lock levers are
mounted in brackets which are incorporated in the barrel
clamp located just behind the flare of the guide tube.
The portable tubular magazine can be pushed into the
~uide ~ube llntil the lock ring is held behind one of two
lock lever teeth, however, when the lock ring is locked
behind the front tooth the cartridge retainer lifter has
not yet made contact with the lifting ramps so no
cartridges are released from the portable tubular
magazine.
Lock levers are held in the locking position by
compression springs located in the lock lever mounting
brackets. Pressure on the back end of the lock levers
cause the teeth to be lifted clear of the lock ring and
the portable tubular magazine can be withdrawn from the
guide tube.
In order to avoid obstructing the line of sight or the
guide tube slot a two-piece barrel clamp can be used to
secure the barrel to the guide tube.
Fitted over and supported by the guide tube, the fore end
is made of steel tubing having wooden side grips and,
- 25 like the guide tube, the fore end is slotted on it's
underside to provide a channel for the cartridge retainer
` housing and lifter.
Standard unaltered~slide bars connect the fore end to the
mechanism inside of the receiver and they prevent any
~ 30 turning of the fore end which would occlude the slot
"~ opening on the guide tube.
The sliding fore end is replaced by a fixed, slotted
forearm in shotguns or rifles employing lever action or
auto-loading mechanisms.
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105
The forward travel of the fore end is limited by the
barrel clamp, therefore, the wooden side grips cover only
that part of the fore end tubing that does not have to
pass under the back end of the lock levers.
When the portable tubular magazine is used to store
cartrldges it can be made wa-tertight by closing the open
~nd with a rubber cap and by the use of rubber ~askets in
~he end cap and on the end of the stem of the cartridge
retainer under the lifter.
DESCRIPTION OF DRAWINGS
FIG. 1 is a side view, partly in section, of the guidé
tube containing a portable tubular magazine and clamped
to the barrel of a firearm.
FIG. 2 represents line 111-111 of FIG. 1.
Drawings are not to scale in order to show more clearly
details of the various components and the receiver and
the stock of the firearm are not shown.
BEST MODE FOR CARRYING OUT THE INVENTION
The main body component of the portable tubular magazine,
guide tube and fore end are sawed from lengths of round
steel tubing and matching slots are then milled in the
underside of the guide tube and fore end pieces while a
male thread is cut on one end of the section forming the
portable tubular magazine.
`.25 A press and forming dies are used to produce the rear
taper on the portable tubular magazine as well as the
~`barrel clamp halves and the flare at the front end of the
guide tube.
Lock lever slots in the guide tube flare and the square
hole in the end of`the cartridge retainer housing are
punched in a press.
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106
The cartridge retainer, cartridge retainer lifter,
cartridge retainer housing and the end cap are cut and
shaped in a la-the from lengths of cold rolled round
steel. Blind holes are drilled in the end cap and the
cartridge retainer housing sections and a round hole is
drilled through the center of the piece to be used for
~he button-shaped cartridge retainer liPter. In the
la~he used to drill these holes the edge of the l.ifter is
beveled and a female thread is cut in the end cap before
~he pieces are parted off from the length of round stock.
Before a cartridge retainer section is parted off from
the length of round stock the end is turned down to form
a stem over which the cartridge retainer lifter will be
staked. The square section of the cartridge retainer stem
and the beveled face of the cartridge retainer is then
formed by milling.
Three straight sides must be milled onto the end cap and
after the square hole is punched in the cartridge
retainer housing it is welded over a hole drilled for
the cartridge retainer in the underside of the portable
tubular magazine on the taper at the back end.
From a spring-like coil wound from cold drawn square
steel stock, lock ring segments are cut and welded on to
the forward part of the portable tubular magazine.
Cartridge retainer lifting ramps are sheared from cold
drawn square steel stock and are fastened to the
underside of the guide tube by welding.
`~With the compression spring over the square stem the
cartridge retainer is inserted into it's housing and the
`30 lifter is staked to the end of the stem over a rubber
gasket outside of the housing.
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107
After lock levers have been formed by stamping, a shallow
blind hole is drilled in the underside to the rear of the
hole drilled for mounting the lock levers. Another
shallow blind hole is drilled in the barrel clamp
opposite to the one in the lock lever. Together these
holes form the pocket in which the compression spring is
held when the lock lever is riveted between the mounting
bracket~.
The barrel clamp is bolted together through a hole
drilled in the clamp between the barrel and the guide
tube and the lower ends of the barrel clamp are riveted
to the guide tube to help preserve it's roundness.
INDUSTRIAL APPLICABILITY
Portable tubular magazines, especially in shotguns, are
well suited for police or military use during situations
where there exists some urgency in reloading. It is also
possible to achieve an added degree of saEety when
carrying a loaded shotgun in a police or military vehicle
because the portable tubular magazine can be locked in
the guide tube without releasing any of it's cartridges.
Easily made watertight a portable tubular magazine can be
used to fully load a firearm with dry cartridges during
periods of inclement weather.
