IMPROVEMENTS IN BREECH-LOADING FIRE-ARMS
Year: 1875

page_text: PROVISIONAL SPECIFICATION left by Alexander Melville Clark at the
Office of the Commissioners of Patents, with his Petition, on the
14th August 1875.- A communication from abroad by Henri
Achille Ludovic Delsarte and Jules François Le Birt, both of Paris,
France.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN BREECH-LOADING FIRE-ARMS," to be as
follows:-
This Invention relates to an improved construction of breech-loading
fire-arm, the features of novelty in which arc,-
1st. The general arrangement of the fire-arm.
2nd. An improved means for preventing escape of gas at the breech,
which consists in a plug attached to the front end of the sliding breech
bolt having parallel circular grooves, forming as many chambers for the
gases that may escape past the head of the plug to lodge in.
3rd. A groove at the rear end of the sliding breech bolt, the said
groove being made in an oblique direction, the length and inclination of

page_text: the groove being such that on rotating the sliding breech bolt previous
to drawing it back this inclined groove will draw back the striker only
half the distance necessary to cock the gun, the cocking being
completed by drawing the bolt completely back and sliding it forward
again to close the breech.
4th. The use in combination with the above groove of a safety notch
made at the extreme rear end of the bolt quite clear of the said
groove.
5
In order that the Invention may be more readily understood, I have
illustrated it in the accompanying Drawing, Figure 1 of which shows a 1
longitudinal section of the fire-arm taken on the line 1, 2, Figure 2,
with the action in the cocked position; Figure 2 is a plan or top view
of the same; Figures 3 and 4 show a side view and cross section on
line 3, 4, Figure 3, respectively of the breech closing bolt.
The letters of reference apply to all the four Figures.
a, stock; b, breech piece attached to stock a; c, barrel; d, sliding
bolt; and e lever handle; f, plug and gas check secured by a set screw g
to bolt d; h, circular grooves around plug f, forming chambers to
receive the gases which may escape past the head of the plug;
i, cylindro-conical hole bored through the centre of the plug for the 2
passage of the needle or striker 7 which is screwed into the head of the
rod m, which slides through screw plug n closing the rear end of the
breech bolt; j, cartridge; o, spiral spring enclosed between plug n and
head ; p, r, s, grooves in the bolt d in which the stud v engages in
cocking and firing the arm; t, safety notch; u, hammer to which rod m 2
is screwed; v, screw stud thercon for cocking the gun; x, sear or detent
attached to spring y; z, trigger pivoted on sear x; w, trigger guard.
The following is the action of the fire-arm, the gun being in the
cocked position shown in the Drawing on pulling trigger z sear x is
drawn down and liberates hammer u; the spring o drives forward the 3
striker, and the part u is caused to strike the rear end of the sliding
breech bolt. In this movement the stud v traverses groove p. In
order to re-cock the gun the bolt d is first turned a quarter round by
means of lever handle e, during which movement the inclined or can
grooves acts on stud v so as to draw back the striker a distance equal 3
to that between the dotted lines 1, 2, Figure 3, which is half the motion

page_text: necessary for cocking. The bolt is then drawn back, the hammer
passing over and depressing the detent x. The cartridge is then
inserted and the bolt again slid forward, together with the hammer, until
the latter, meeting the detent x, is retained, the bolt only continuing its
forward movement, the stud v passing out through groove r. The
cocking is thus completed, and the lever handle e being then turned
down the un is woods for firing