Straight Pull Bolt Gun.
Year: 1898

page_text: Date of Application, 1st Nov., 1898-Accepted, 23rd Dec.,
1898
COMPLETE SPECIFICATION.
Straight Pull Bolt Gun.
I, BETHEL BURTON, of 23, Irving Place, Brooklyn, State of New York, U.S.A.,
Inventor, do hereby declare the nature of my invention, and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement:
-
The invention relates to what is called a straight pull bolt gun and involves
the bolt construction, the magazine construction, and the cartridge feeder or
clip and a combined bayonet and rest.
It is constructed as follows, reference being had to the accompanying draw-
ings, in which :-
Fig. 1 is a side elevation of the breech and magazine part of a breech loading
gun according to this invention;
Fig. 2 is a longitudinal section of the breech part of the gun, with breech
closed;
Fig. 3 is a broken section, with breech open;
Fig. 4 is a top plan of the breech frame, bolt, and magazine;
Fig. 5 is a bottom plan of frame, with magazine removed;
Fig. 6 is a cross section through frame and bolt, just in rear of the trigger,
hand lever omitted;
Fig. 7 shows side and bottom views of hand lever;
Fig. 8 is a bottom view of the bolt body, and
Fig. 8 an end view;
.
Fig. 9 is a section of the hammer or striker head and sleeve, and
Fig. 9 a section of same with part of firing pin applied;
Fig. 10 shows plan, sections, and broken elevation of bolt cover,
Fig. 11 is a plan and elevation of the bolt sleeve, and
Fig. 11 a plan and section of the bolt collar;
Fig. 12 is a broken side elevation of the magazine portion of the gun with
cartridges and clip in loading position;
Figs. 13 to 16 show cross sections through the gun frame 1, stock A, or maga-
zine B, on different vertical planes; Fig. 16 showing also the cartridge clip,
the magazine cover being omitted;
Fig. 17 is an enlarged detail section of the clip or cartridge holder;
Fig. 18 a rear view of the clip;
Fig. 19 an edge view of the clip;
Fig. 20 an end view of the clip;
Fig. 21, a plan; Fig. 22 a rear elevation, and
Fig. 23 a vertical section of the cartridge releasing device, by which the cart-
ridges are released from the clip or holder, in charging the magazine from the
clip;
Fig. 24 is a broken side elevation of the front of the gun, with the bayonet
turned back;

page_text: is a broken section and elevation of the front end of the gun with the
bayonet "fixed";
Fig. 26 is a reduced side elevation showing bayonet in use as a rest;
Fig. 27 is an elevation of modified bayonet blade;
Fig. 28 is a cross section of the bayonet at the pivot and a front elevation of
the gun;
Fig. 29 is a section of the bayonet;
Fig. 30 is a detail of the bayonet holding catch, and its socket, detached from
band E¹.
The numeral 1 indicates the frame of the gun; 2 the barrel socket; 3 the
bolt housing, and 4 the bolt body. The bolt has a cover 7, and an extractor 5
is interposed between the bolt and cover in usual manner. The bolt cover slides
in ways in the frame as usual.
The bolt body has mutilated screw sections 8, 8, both at front and rear, these
screw sections or segments engaging corresponding threaded segments 9, 9, in
the frame to lock the bolt in the closed position. The segment 8 at the rear of
the bolt is of greater diameter than the front segment 8, and the threaded
segments in the frame correspond to those in the bolt.
A sleeve 11 surrounds the bolt body between a fixed shoulder 12 and a collar 13,
which collar is attached to the bolt body by a screw or pin.
The sleeve 11 has a projecting pintle 14, which forms a pivot for the handle
lever 21. Sleeve 11 has fins 16 which enter longitudinal groove 17 in the frame
and slide therein. Sleeve 11 is also connected by a dove-tail or similar connection
to the bolt cover 7, which cover is guided to move lengthwise in the frame in
usual manner. The sleeve 11 is thus held against rotation around the bolt
body, but the bolt body may work in this sleeve in locking and unlocking, as
will be described.
The collar 13, which is attached to the bolt, has a projecting knob or boss 18.
The lever 21 has a handle portion 25, and is held to pintle 14 by a screw, or
similar device, but permitted to rock on said pintle as a fulcrum. Lever 21
has a socket 23, which receives the knob 18, this socket being of such size as
to permit the necessary movement. When the knob is drawn back from the
position shown in full lines, Fig. 1, it swings the lever to the position indicated
in dotted lines, thus rocking and unlocking the bolt. A continuation of the
backward pull opens the breech of the gun by drawing the bolt backward.
backward movement of the handle 25 in unlocking and opening the bolt is
practically continuous, and although not exactly in a straight line may be nearly
so, if the parts are proportioned and located properly.
The
The bolt 4 has a groove 26 extending lengthwise, and a groove 27 extending
in inclined direction partly around the bolt. The bolt having three locking
segments as shown, must make one sixth of a rotation in locking and unlocking,
but this of course may be varied if a greater or lesser number of locking or
mutilated screw segments be used, as is common.
Arm 28 of the carrier lever 32 extends into the groove 26 in the body of the
bolt. When the bolt is rocked to unlocked position, and drawn slightly back-
ward to open the breech, this arm 28, in the straight groove 26, prevents rotation
of the bolt during the backward movement of opening of the breech, or the
forward movement of closing it. The final rotation of the bolt in locking causes
the cam groove 27 in the bolt to act on arm 28 of the carrier lever to press arm 28
forward and depress the carrier, as will be explained.
The striker 31 has an arm 33 which projects forward to engage the sear 41,
and is released by a pull on the trigger 42. The arm 33 moves in a groove in
the frame, when the bolt is near its locked position, and is therefore prevented
from rocking with the bolt body in the locking and unlocking. The rear end
of the bolt has a cam face a¹, which engages a corresponding cam or incline a
at the front of the striker 31, and the partial rotation of the bolt in unlocking
presses back the striker head by the engagement of these inclines, so that the

page_text: scar 41, pressed up by a spring as usual, may hold back the striker until the
trigger is pulled. The engagement of inclines a¹ a² will prevent the forward
movement of the striker except when the bolt is locked.
The striker 31 carries a sleeve 38, through which the firing pin 36 passes. The
firing pin is pressed forward by a coil spring 37 as is common, said spring acting
against an abutment in the bolt and the nose of the firing pin.
The firing pin head b¹ is secured to the pin, and has a cam face c¹ at its front.
The sleeve 38 screws into the striker head 31, and has a cam face at its rear
(see Fig. 9). The sleeve 38 may be screwed slightly forward or back, to compen-
sate for the wear, or difference in the length of the firing pin. The pin head b¹
has an arm, by which the pin may be partially rotated, and thus drawn back-
ward by the engagement of the cam c¹ with sleeve 38.
When so drawn back
the firing pin will not reach the cartridge, even if the trigger is pulled. The
position of arm serves to indicate whether the firing pin has thus been with-
drawn to safety position.
The collar 13 has an extension el which covers the cam of striker head 31,
except as one part or the other is cut away to permit necessary movement of parts.
The bolt construction may be used with either single loading guns or with
magazine guns.
In all small arms which use smokeless powder, it is necessary that the bolt
be locked very firmly, to resist the enormous pressure employed. A mutilated
screw locking device, both at the front and rear of the bolt, makes what is believed
to be the very best means for locking the bolt, but as such locking mechanism
has heretofore required that the soldier or sportsman should make an angular
movement of the hand by which the gun has been worked, such a bolt gun has
been criticised by military men.
"
By the construction described a gun is made which is substantially a "straight
pull gun, that is, a gun in which the breech can be opened by a nearly straight
pull backward, and in which the bolt can be locked with all the firmness of a
double mutilated screw, giving about twice the strength commonly used in
locking the bolt. Thus very powerful ammunition may be used, and the opera-
tion of loading is simple and direct.
The magazine described herein is what is known as a hopper magazine, or
gravity feed magazine, and is more particularly shown in Figs. 1, 12, 13, 14,
15 and 16.
The receiver 51, under the bolt, has a recess large enough to contain one cart-
ridge, and a carrier or lifter lever 52, which is actuated by a spring 53 to raise
this cartridge. The bolt engages the end of lover 52 to depress the carrier by
the engagement of cam 27 with arm 28 of the carrier lever, and the unlocking
of the bolt permits spring 53 to raise the carrier when the bolt is open, as is
common.
The magazine has its outer wall composed of plate 55, and its inner wall of
the rounded or beveled side plate of the frame 56. The side wall 55 is curved
according to the shape of the cartridges, the front curving on something like a
parabolic curve, and the rear part of the magazine curving on different lines,
so that the magazine when measured in transverse section at any vertical plane,
presents an opening of size to receive the proper number of cartridges measured
in corresponding section.
As the bullet ends of cartridges of modern construction are much smaller than
the cartridge butts, the magazine is adapted to receive the desired number of
cartridges, usually five, with the least projection at the side of the gun.
The passage 57 through the side wall of the gun, indicated in dotted lines,
Fig. 12, is wider at the rear than at the front of the magazine, and inclines about
as indicated, being in form and size to pass a cartridge. A gate 58, having
handle 59 outside the gun, may be swung so as to partially close this passage,
and thus shut off the supply of cartridges from the magazine to the carrier, so

page_text: that the gun may be used as a single loader. The cut off gate may be held in
either of its adjusted positions, by friction or otherwise.
The magazine preferably has a hinged cover 69, which may be held in either
open or closed position by a spring in receptacle 71, in the same manner that
blades of pocket knives and the like are held either open or closed.
The cover
preferably projects slightly at one end of the magazine, so as to be readily thrown
open or closed. The magazine is preferably held to the frame by grooves O, O.
In the rear of the magazine there is a recess 72, in which the cartridge releasing
device may be placed, and held by friction or by a set screw.
The cartridges in the magazine can be cut off from the receiver by moving
gate 58. If the gate 58 be slightly lowered, the lowermost cartridge in the
magazine will pass through passage 57, under the impulse of gravity, when the
gun is in usual firing position, and the carrier down, as in Figs. 2, 15, 16. The
carrier is pressed down by the locking movement of the bolt, as explained.
A carrier plate K is pivoted to the front end of the extension 52 of the carrier
lever, and this plate extends over the top of lever 52, and down at the side
thereof. The front end of plate K extends forward of the pivot, and by engage-
ment with the frame, (Fig. 2) causes the plate K to fold down close to lever 52,
when the bolt is closed, so that a cartridge can pass through the receiver. The
receiver is only sufficiently large to receive one cartridge at a time, and this cart-
ridge can only be admitted when the bolt is locked. Thus the jamming of cart-
ridges in the receiver is prevented.
When the bolt is withdrawn to open the breech, the lever 52 is lifted by
means of spring 53, and as the end of the plate K encounters shoulder / in
the frame, the plate K swings on its pivot to lift the rear end of the cartridge.
(See Fig. 3.) The side wing of plate K and lever 52 extend in front of passage 57
from the magazine, to prevent cartridges from entering the receiver through
the side passage when the carrier is raised.
The cartridge holding clip or magazine charger 81 is a single piece of sheet
metal, in the form of a shallow trough, having its edges turned in to embrace
the heads of cartridges, and preferably curved, to conform to the shape of a
pack of cartridges. (See Fig. 12.) In the respects named this clip is old and
well known. The present improvement in the clip consists in making the hooks
or catches 82, one at each end of the clip, of the same material as the body of
the clip, and to be operated as explained. The metal of the clip is preferably
sheet steel, neither spring tempered nor annealed. The hook 82 is formed
at the end of a tongue, and the tongue is made by two slits c one at each side
of the tongue, and between these slits and the hooks 82 the metal d of the
tongue is preferably formed to extend back a trifle from the general line of the
surface of the clip. (See Fig. 20.)
The cartridge releasing or hook detaching device 73 is shown as a rectangular
piece made to fit the recess 72 in the magazine. When the cartridges are to be
fed loosely into the hopper or magazine, this piece 73 is not required. But in
loading from clips 81, this detaching piece is applied in the magazine recess 72.
Piece 73 has a vertical passage e, which receives the lower end of clip 81, and
as the ends of the clips are alike, either end may be applied as in Fig. 12.
Wings at the sides of piece 73 guide the clip downward in passage e.
Wedges n in the detaching piece 73 in the path of movement of projections d
of the clip, extend in front of said projections, and as the clip is pressed down
these wedges press back the tongue between the slits c, including the hook, as
shown in Fig. 17.
The piece 73 is recessed behind the wedges n to leave room for the tongue
and hook to move back, thus leaving the cartridges free to move down through
the trough of the clip, and into the magazine.
The clips 81 are usually made of sheet metal which is not spring tempered,
so that when the hook 82 is pressed back as in Fig. 17, it will stay back, and
the cartridges may be pressed out of the clip, or permitted to move down by

page_text: gravity. In this way the clip may be entered into an empty magazine, the cart-
ridges released and pressed out, and the clip withdrawn; or, if the magazine
be full, the clip may be left as in Fig. 12, and the cartridges will then feed down
by gravity as those below are fed into the gun. Thus the clip may be used
as an auxiliary magazine, and about ten cartridges can be carried to a gun with
a magazine capable of inclosing five cartridges.
The clips 81 can be easily refilled, and the hook 82 can be pressed forward
to retain the cartridge heads by the fingers, or by slight pressure from a tool.
These clips are exceedingly cheap to make, are symmetrical and hold the cart-
ridges with sufficient firmness so that packages of cartridges can be handled with
about the same facility as a single cartridge without the clip.
The detaching device 73 does not much interfere with the dropping of loose
cartridges into the magazine, and need not be removed from the gun when it is
not desired to feed the magazine from the clips.
The gun barrel D and front stock A¹ may be of usual construction. The
front band E, I prefer to have near the muzzle of the gun, and this band E is
connected by a screw or rivet H, which serves as a pivot on which the bayonet
and rest turns.
The bayonet 85 is a light blade, preferably not above six ounces in weight,
and may be of the forms shown in Figs. 27 and 29, but this is not essential. The
shank is slotted at 86, and the shank end rounded.
A plug 91 pressed out by a spring 92, is held in socket 93, which socket is held
to the gun at the second band E and may have a swivel or sling 94 attached.
The bayonet when turned out of use has its sharp edge extending into a groove
in the front stock, and its point extending into a slight recess in plug 91. To
“fix” bayonet, the point is swung out from the recess in the plug, then the
bayonet is slipped along until the end of the slot 96 next the shank of the
bayonet is against screw H. The bayonet may then hang as a pendulum, and
be used as a rest, as in Fig. 26, the weight of the gun resting on the rounded
end of the bayonet shank.
To "fix" bayonet the point of the bayonet is turned forward, and the bayonet
slipped back, as in Fig. 25. A spring catch 98 secured in the stock, engages
a notch 96 in the bayonet and holds it fixed. A thumb piece 97 on the spring
serves to disengage the spring catch when desirable, so that the bayonet may
be slipped forward, and then reversed, turning on screw H.
This bayonet adds very slightly to the weight of the gun, and as no bayonet
scabbard is required, the soldiers equipment is considerably lightened, and an
inconvenient impediment is gotten rid of. The light blade is an efficient weapon,
and a very convenient gun rest in long range firing from a prone or lying
down position.
رو
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
1. In a straight pull bolt gun, the handle arranged to reciprocate in a practic-
ally straight line, and the mutilated screw locking bolt having large and small
screw segments and arranged to be opened, closed, and rotated by the practically
straight pull of the handle by the lever.
2. The handle moving in a practically straight line the bolt connected thereto
and having its reciprocating and rotating locking movements communicated
by said handle, and the hammer arranged to be cocked by the unlocking of the
bolt, in substantially the manner described.
3. The magazine and the cartridge lifting lever having a carrier plate pivoted
on the lever and arranged to lift the cartridge and to prevent the entrance of
cartridges to the magazine when the carrier is raised.
4. The cartridge releasing device having a recess for the reception of the

page_text: cartridge clip and wedge for detaching the clip detent, and being applicable
to the magazine, substantially as described.
5. The cartridge clip made of a single piece of metal and having the retaining
hook formed on a tongue of the metal and projections by which the hook may be
detached, substantially as described.
6. The reversible bayonet constructed to be used also as a gun rest and to be
held in extended or reversed position, and having means for holding it “fixed”
or turned back, substantially as described.
7. The novel' features of construction and combinations of mechanical elements
substantially as described and claimed.
D
11
11000
CRUIKSHANK & FAIRWEATHER,
Chartered Patent Agents,
62, Saint Vincent Street, Glasgow, Agents for the Applicant.