Improvements in Fire Arms.
Year: 1892

page_text: COMPLETE SPECIFICATION.
Improvements in Fire Arms.
I WILLIAM DUNDERDALE FORBES of 1300 Hudson Street Hoboken State
of New Jersey United States of America Mechanical Engineer do hereby
declare the nature of this invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:
The object of my invention is to produce a fire arm of great simplicity
cheapness and durability, capable of very rapid firing in the hands of those not
previously accustomed to its use, and of so few and simple parts as to require no
tools to connect them together or take them apart, and further it has for its
object to dispense with all spring-operated parts except for the firing-pin, and to
so simplify the necessary motion of loading and locking, exploding the cartridge
and extracting and ejecting the empty shell or case as to make it practically
impossible for those using the arm (however unskillful) to do anything but
produce the required results. The following description with reference to the
accompanying drawings will clearly explain the nature of my invention and the
mode of carrying the same into practice.
Figure 1 is a side elevation of my improved rapid firing breech leading arm with
part of the barrel cut off.
Figure 2 is a similar view showing the connecting rod the breech bolt and the
locking segment in different positions from those in which they appear in Figure 1.
Figure 3 is a plan view.
Figure 4 is a horizontal sectional view.
Figure 5 is a perspective view of part of the handled or rotating piece with the
locking segment and the trigger, these parts being detached from their
surroundings.
Figure 6 is a perspective view of the breech bolt and extractor detached.
Figure 7 is a perspective view of the roller gate or safety device and
Figure 8 is a perspective view of that end of the connecting rod which connects
with the breech bolt.
Figure 9 is a perspective view of what may be termed the pin slide.
Figures 10, 11 and 12 are respectively a side elevation a plan and a longitudinal
section of a modified form of my firearm.
Figures 13 and 14 are respectively a sectional plan and a side elevation of the
breech holt of the arm illustrated by Figure 12.
Figures 15, 16 and 17 are views of the operating eccentric, its ring or strap and
the bolt locking device.
In these drawings the main parts of the firearm which have motion are generally
indicated by numbers, while those main parts which have no motion are generally
indicated by large letters and the details of the various main parts are indicated by
small letters.
Referring to Figures 1 to 9 A is the barrel which may be screwed into the front
end of the frame or receiver B and into the rear of this frame is screwed the cap
piece D. The frame or receiver B has on its upper side an opening a (Figures 3
and 11) for the admission into the breech chamber of fresh cartridges from a
magazine of any suitable construction, which it has not been thought necessary to
ndicate in the drawing but which may be secured upon a suitable pin such as is
shewn at T on the top of the frame or receiver.
In the side of this frame or receiver is an opening 6 (Figures 2 and 4) for the
lischarge of the empty cartridge shells or cases as they are successively drawn
from the barrel. The rear end of this opening b when the parts are fitted together
D

page_text: is closed by a removeable slide or part C of the frame which carries the pivot
pin for the rotating operating handle to be grasped by the user of the
weapon. The general construction of this pin slide C is shewn in Figure 9 which
however is particularly intended to show the pin-slide of the modified form of my
firearm illustrated by Figure 12. This pin slide is held in place by the cap D.
The trigger 6 is pivoted to this slide C in a horizontal elot or notch k (Figure 9)
so that the inner end of the trigger may project into and through a longitudinal
slot in the breech bolt 2 which is contained within the receiver or frame B and
has the necessary longitudinal motion imparted to it backwards and forwards at
proper times by means of the operating handle h. This handle is connected to
a segmental part provided with dovetailed edges to w to engage with corre-
sponding grooves at ss in the frame or receiver B to lock the breech bolt to the
frame or receiver while the bolt is in the closed position, as shewn in Figure 4 for
instance.
For this
To impart the necessary longitudinal reciprocating motions to the sliding breech
bolt 2, a connecting rod K is connected to a crank pin p on the segmental
portion of the rotary handle and at the opposite end it is connected with the
bolt 2 in such a manner that there is an intermediate lost motion.
purpose the outer end of the connecting rod K has an elongated slot or recess k
within which is contained the cylindrical end of the laterally projecting lug V
upon the bolt 2 the slot being in the present instance about twice as long as the
diameter of the cylindrical part of the lug V. The object of this lost motion is to
enable the bolt to remain in its forward locked position in which it is held by the
dovetails on the locking segment during that part of the revolution of the
handle that the locking segment is in engagement with the locking bolt.
In the modified form of firearm illustrated in Figures 10 to 17 the rotary
handle carries a dovetailed segment to engage with dovetailed notches
or recesses in the side of the frame or receiver B to lock the breech bolt to the
frame through the lug V when the breech bolt is closed. I prefer however to
construct the breech bolt as shewn in the arrangement illustrated by Figures 1 to 8
so that the locking segment h³ will engage directly with the breech bolt as well as
with the frame. For this purpose a shoulder S (Figures 4 and 6) is formed upon
the bolt 2 to project through the side opening of the frame or receiver B and
the rear edges of this shoulder is bevelled to correspond with the bevel w on the
forward edge of the locking segment and the incline of the dovetailed notches in
the frame B.
The connecting rod K cannot carry the bolt quick enough to the end of its
forward motion to avoid the contact of the segment and the shoulder S so the
advance edge of the rotating segment at x Figure 2 is made on a somewhat
smaller curve than the rest of the locking edge of the segment to form a cam-like
advance edge. As the segment enters the notches in the frame or receiver this
cam edge at a comes into contact with the rear edges of the shoulder S of the
breech bolt and pushes the latter home or to its extreme forward position and
holds it there locked by the engagement of the part at to with the notches in the
frame and with the bolt, and until the rotary handle, as it is turned, carries the
segment out of engagement with the breech bolt.
The firing pin 3 is contained within the breech bolt 2 and the spiral spring 5
tends to push this firing pin out to the forward end of the breech bolt (Figure 4).
But when the breech bolt has reached the end of its backward movement carrying
the firing pin 3 with it against the action of the spring 5 the trigger 6 will engage
with the shoulder a³ of the firing pin to retain the latter while the breech bolt is
.moved forward again. When the bolt has reached the full extent of its forward
movement, it will have closed the breech, the trigger will have been moved (by a
pin or projection o on the portion of the rotating handle h coming into contact
with the outer end 6¹ of the trigger 6) to release the firing pin which then
flies forward under the action of the spring 5 and strikes and explodes the
cartridge.

page_text: The trigger is positively operated without the use of a spring and is set into
position to engage with the shoulder by the shoulder coming into contact with
the forward side of the trigger when the breech bolt reaches the end of its
rearward movement. As the breech bolt is moved forward again the trigger 6
cannot be turned by the pressure of the firing pin and its spring, beyond the
position at about right angles to the longitudinal axis of the firing pin.
Instead of employing the ordinary spring cartridge extractor, I make the
latter of rigid material, free at the proper moment to have a limited movement at
about right angles to the action of the breech bolt. This rigid extractor 4 is
carried by the projecting arm or lug V of the breech bolt, having a cylindrical or
semi-cylindrical part adapted to a corresponding opening in the lug.
As the inner bevelled face of the extractor nose meets the rim of the freshly
introduced cartridge when the bolt begins to move forward, the extractor is pushed
out laterally in the slot v of the lug V of the bolt, but when the bolt is carried to
the closed position, the outer inclined face of the extractor nose comes into contact
with the inclined forward end of the slot & in the frame, whereby the extractor is
caused to close down upon the rim of the cartridge.
For the purpose of locking the cartridge extractor 4 upon the rim of the
cartridge during the backward movement of the breech bolt, a notch y is formed
in the edge of the extended arm of the extractor, and corresponding notches are
formed on the front side of the lug V of the bolt while a pin or projection
carried by the connecting rod K, within the slot k, is adapted to enter these
notches in the lug V of the bolt and in the cartridge extractor to prevent lateral
movement of the latter, when the connecting rod is drawing the breech bolt back
again. In order to hold the cartridge shell or case firmly during the extracting
movement and prevent it from moving away from the extractor, I may provide on
the outer end of the breech bolt a projection s¹. This projection is not absolutely
necessary as the firing pin will, to some extent, answer the same purpose.
I prefer to use in connection with and so as to form part of, my fire-arm, a
device which may be termed a safety gate consisting of a hollow slotted cylinder 8
(Figures 4 and 7) free to have a partial rotary movement within the frame or
receiver B, and embracing the sliding breech bolt 2, and caused to make a partial
rotation thereon as follows:-The lug V of the bolt 2 Fig. 12 is cylindrical in
part but rectangular where it joins the main part of the bolt, see Fig. 1+ and for
the formation of the shoulder S, Figures 6. As the bolt moves back in the slot b
Figures 12 and 4, it also moves in the slot of the cylinder 8, Figure 7; when
the upper rear corner of shoulder S comes in contact with the point c' at the base
of the bevel c', it presses thereon and turns the cylinder 8 partly round the bolt
with the result of presenting the opening c in the cylinder to the feed opening a in
the receiver B, Figure 3, and at the same time closing the side opening or guide-
slot b. This action allows a cartridge to be fed through the opening of the
receiver B and through the slot c of the cylinder 8 and prevents such cartridge
from rolling out through the slot b.
As the bolt moves forward the lower forward corner of the shoulder S,
Figure 6 comes into contact with another bevel edge of the cylinder 8 (Fig. 7)
so as to turn the cylinder to the same position it occupied before the backward
movement of the bolt, in which position it cuts off or closes the opening a and
opens the guide slot b. The slot in the cylinder 8 (Fig. 7) is to allow for the
movement of the trigger.
It
This cylinder or safety gate 8 it will be seen answers several purposes.
prevents the cartridge from falling out or becoming otherwise misplaced; it guides
the cartridge to and into the chamber, it covers the extractor hole until the
cartridge has fairly entered the chamber, it has moreover one other effect which has
been greatly desired by those working on rapid firing arms that is to say it
effectually and completely cuts off the cartridge in the receiver, from those in the
feed magazine, until the former has been fed to the chamber, fired, withdrawn, and
ejected, so that in case of premature explosion or hang-fire no danger can ensue.

page_text: In the latter case experience has shewn that the force of the explosion expends
itself harmlessly through the guide-slot b and the same result would ensue in the
case of premature explosion and under these conditions the bolt 2 cannot be driven
back because of the peculiar construction of the bevel segments w w which hold it
locked save at the point of extreme backward movement, at which time there is no
likelihood of premature explosion or hang-fire taking place.
The operation of my arm will be readily understood from the foregoing
Wescription but I may explain the manner of ejecting the cartridge shell or case
which is obtained as follows:-
Referring to Figure 4 the extractor 4 is shewn in position for holding one side
of the cartridge head and the firing pin 3 is in position to have struck the primer :
as the bolt moves backwards the tension of the spring 5 exerts itself through the
pin 3 on the back of the cartridge shell which has just been fired with a tendency
to force it away from the face of the bolt: this tendency is resisted by the extractor
and the empty shell is strained to the right, its forward right hand end dragging
along the inner right hand side of the chamber; as soon as the bolt has been drawn
back far enough the empty shell is no longer supported by the side of the chamber
and is forced out through the ejection slot Figure 4.
Instead of operating the breech bolt through the medium of a connecting rod as
above described I may use other means and I have shewn in Figs. 10 to 17 a
construction in which the rotating part or handle which carries the locking
segments w w is provided with an eccentric 1 or strap and ring.
The handle which carries this operating eccentric 1 is as before free to turn
upon the pivot m being retained in position upon the latter by a nut E
(Figure 12).
.
There is fitted upon this eccentric 1 or rather within an annular groove formed
therein a ring or strap 7 which at a suitable point has an opening Q for the reception
of the end of the laterally projecting arm or lug V of the bolt 2 (Figures 12, 15
and 16).
This ring is mounted eccentrically to the pin m upon which the handle turns, it
will therefore be evident that as this handle is rotated a longitudinal reciprocating
motion will be imparted to the sliding breech bolt 2 within the frame or receiver B.
When the breech bolt reaches the forward end of its motion it will have pushed
into the barrel the fresh cartridge and will have closed the breech (Figure 12)
while on the return movement against the action of the spiral spring 5 the empty
cartridge shell or case will be withdrawn and ejected through the lateral opening b
as herein before described.
As the hole Q of the eccentric strap or ring 7 fits over the lug V the outer end
of the extractor 4 is firmly held in place (Fig. 12). It will be understood that the
extractor fits easily and not so tightly as to prevent the limited inward and outward
movement which it is intended to have.
In the bottom of the groove, which receives the eccentric strap or ring 7, for
about a quarter of a circle, there is formed an inclined groove (Figure 17)
deepest at and a little deeper than the rim of the cartridge the groove gradually
reducing in depth up to the point where it merges into the surface of the ring.
This groove is situated opposite to and is adapted to receive the outer end of
the cartridge extractor and so that its deepest part will be opposite the end of the
cartridge extractor 4 when the end of the breech bolt meets the cartridge. As
the bevelled edge of the extractor meets the rim of a cartridge it is pushed out
laterally in the slot or groove of the lug V of the breech bolt the slot = 2¹
admitting of the movement of the outer end of the extractor. As the bolt is
carried forward by the eccentric the rear inclined edge of the extractor 4 comes
into contact with the bottom of the slot in the receiver which causes the extractor
to close down upon the rim of the cartridge and as by this time the eccentric 1 has
reached such a position that the extractor has reached the end of the grooves z
the outward movement of the extractor is prevented by its contact with the
bottom of the groove containing the ring 7.

page_text: पलप
many
may be employed as a small arm and stocked like an ordinary musket.
For instance in Fig. 19 the fire arm is shewn as it may be arranged either
singly or in groups in a suitable mount.
Fig. 20 shews the fire arm stocked like an ordinary musket.
Preferably, however the arm is constructed to be used in the manner illustrated
in Fig. 18. For this purpose a button P as shewn in Fig. 11 is provided on
the side of the frame of the arm, while on the belt 51 of the user is secured
a notched socket 52. This notched socket is shown on a larger scale in
Fig. 184. The button P on the gun is dropped into the socket on the user's belt
so as to find a firm support there and then the barrel of the gun is held in one
hand while the rotating operating handle is turned by the other hand.
The barrel of the gun may be provided in this case with a handhold 53 of wood
or other suitable material for this purpose as shewn in Fig. 18.
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 breech loading fire-arm the combination of the frame or receiver and
a breech bolt therein having a firing pin with a trigger carried by the frame,
a rotating handle on the frame to operate the breech bolt, said handle having a
projection to act on the trigger to relieve the firing pin at each revolution
substantially as herein before described.
2. In a breech loading fire arm, the combination of the frame or receiver, and a
breech bolt therein with means to open and close the breech bolt and a rotating
handle mounted on the frame and connected to the bolt and having a segment to
engage with the frame or receiver and lock the bolt to the latter while the breech
is closed substantially as hereinbefore described.
3. In a breech loading fire-arm, the combination of the frame or receiver and a
breech bolt therein with means to open and close the breech bolt and a rotating
handle carried by the frame and connected to the bolt and having a dovetailed
segment engaging with dovetailed grooves in the frame or receiver to lock the bolt
to the latter, while the breech is closed, substantially as hercinbefore described.
4. In a breech loading fire-arm, the combination of the frame or receiver having
a feed opening for the cartridges and an ejection opening for the cases or shells,
and having dovetailed grooves on one side a breech bolt in the frame, and a
rotating handle mounted on the frame, and connected to the bolt to open and
close it and having a dovetailed segment to engage with the grooves in the frame
or receiver to lock the bolt to the latter while the breech is closed, substantially as
herein before described.
5. In a breech loading fire arm, the combination of a frame or receiver and
breech bolt with a rotary operating handle for the breech bolt and a locking
segment carried by the rotary handle, and engaging with both the breech bolt and
the frame or receiver to lock the bolt in its closed position substantially as herein-
before described.
6. In a breech loading fire-arm, the combination of the frame or receiver and a
breech bolt having a laterally projecting shoulder with a rotary handle carrying a
locking segment to engage with the shoulder on the bolt and with notches on the
frame or receiver to lock the bolt in its closed position, substantially as herein-
before described.
7. The combination of the receiver or frame of a breech-loading fire-arm and
its breech bolt with a rotary handle having a crank pin and mounted on a pivot at
right angles to the axis of the bolt and a connecting rod connecting the breech
bolt with a crank pin on the rotary handle substantially as hereinbefore
described.
8. In a breech-loading fire-arm, the combination of the receiver or frame and
breech bolt with a rotary handle having a crank pin and a connecting rod

page_text: 5
T
connecting the said crank pin of the rotary handle with the breech bolt to operate
the latter, with a loss of motion in the connecting rod, as and for the purpose herein-
before described.
9. In a breech-loading fire arm, the combination of the frame or receiver and
breech bolt with a rotary handle having a crank pin, a connecting rod connecting
the crank pin with the breech bolt, a laterally moving cartridge extractor and a
device carried by the connecting rod to lock the extractor upon the cartridge shell
during the rearward motion of the breech bolt substantially as hercinbefore
described.
10. In a breech-loading fire arm, the combination of the frame or receiver and.
breech bolt having a laterally projecting lug with a rotary handle having a crank
pin, a connecting rod pivoted to the latter and having an elongated slot engaging
with the lug on the breech bolt, substantially as and for the purpose herein-
before described.
11. In a breech loading fire-arm, the combination of the frame or receiver and
breech bolt having a notched laterally projecting lug and a notched cartridge
extractor carried thereby with a rotary handle having a crank pin, a connecting
rod pivoted at one end to the crank pin and having at the other end an elongated
slot to engage with the lug and a projection to engage with the notches on the lug
and as extractor substantially hereinbefore described.
12. In a breech-loading fire-arm, the combination of the frame or receiver and
breech bolt with an operating handle for the latter, having a crank pin and
carrying a locking segment to lock the bolt to the frame and a connecting rod
connecting the crank pin on the rotating handle with the breech bolt with a lost
motion in the connecting rod, substantially as and for the purposes herein before
⚫ described.
13. In a breech-loading fire-arm, the combination of the frame or receiver having
notches on the edge and a breech bolt having a laterally projecting shoulder with a
rotary operating handle for the breech bolt to impart a reciprocating motion to the
latter, the said handle having a dovetailed locking segment to engage with
the shoulder on the bolt and notches on the frame, the forward acting edge of
the locking segment being made cam-like to complete the forward movement of the
breech-bolt, substantially as herein before described.
14. In a breech-loading fire-arm, the combination of the frame or receiver
carrying a pivoted trigger with a tubular breech bolt in the frame and con-
taining a firing pin and having a longitudinal slot through which the nose of the
trigger projects to engage with the firing pin and a rotating handle mounted on
the frame to operate the breech bolt and carrying a projection to act on the trigger
to release the firing pin, all substantially as hereinbefore described.
15. In a breech-loading fire-arm the combination of the frame or receiver and a
breech bolt therein carrying a firing pin, with a rotating handle to operate the
breech bolt and lock the latter to the receiver; a detachable slide in the frame
carrying the pivot for the said rotating handle and a cap to secure the slide in
place substantially as hereinbefore described.
16. In a breech-loading fire-arm the combination of the frame or receiver having
openings for the feeding of the cartridges and ejection of the shells with a sliding
breech bolt in the frame and a rotary slotted cylinder around the breech bolt and
within the frame to open and close the feed opening all substantially. as herein-
before described.
17. In a breech-loading fire-arm, the combination of the frame or receiver having
feed and ejection openings for the cartridges and shells, with a breech bolt having a
lug and a rotary cylinder around the breech bolt and within the frame and provided
with a cam slot in which the lug on the bolt works to open and close the feed
opening for the cartridges substantially as herein before described.
18. In a breech loading fire-arm, the combination of the frame or receiver with a
breech bolt therein having at its front end a lug grooved at about right angles to
the axis of the bolt, for the reception of a sliding springless extractor which.c
.can

page_text: slide in the groove to a limited extent and means for locking the extractor closed.
and for releasing it again substantially as hereinbefore described.
19. In a breech loading fire-arm, the combination of the frame or receiver with
a breech bolt therein, having at its front end a grooved lug, a springless extractor
adapted to the groove, and positively acting devices for locking the extractor on
the cartridge rim and for releasing it substantially as hereinbefore described.
Dated this 12th day of January 1892,
J. H. JOHNSON & Co.,
Agents.