Improvements in Repeating Firearms having a Revolving Cartridge Cylinder, more especially Applicable to Revolvers.
Year: 1898

page_text: Date of Application, 2nd June, 1898-Accepted, 9th July, 1898
COMIDELE DT BCIFICATION.
Improvements in Repeating Firearms having a Revolving Cartridge
Cylinder, more especially Applicable to Revolvers.
I, ALFRED LINES, of 57, Victoria Road, Deal, in the County of Kent, Civil
Engineering Student, 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:-
This invention relates to improvements in repeating firearms, having a revolving
cartridge cylinder, and has reference more particularly to revolvers of the kind
described in the Specification of my former British Letters Patent No. 1328 dated
18th January 1897, that is to say those in which the trigger has a rectilinear
motion parallel or very nearly so to the axis of the cylinder, and is designed to
provide an improved arrangement for rotating the cartridge cylinder and holding
it accurately and firmly in position during the act of firing.
For this purpose a projection is provided on the stem of the trigger, which
engages with grooves provided on the surface of the cylinder, the said grooves
being so designed that, as the trigger is pulled and released the cylinder is caused
to rotate.
In order that the invention may be clearly understood I will proceed to describe
the same by the aid of the accompanying drawings in which
Figure 1 is a sectional elevation of one construction of revolver embodying my
improvements, certain parts, including the cylinder, being shown in elevation.
Figure 2 is a development of a portion of the surface of the cylinder, that is to
say, a portion of the surface of the cylinder laid out flat, in order to show more
clearly the shape of the aforesaid grooves.
The firing mechanism shown in Figure 1 has already been described in detail
in the Specification left with my former application for British Letters Patent
No. 10145, dated 3rd May 1898, the only substantially new feature being the
present invention for rotating the cylinder.
A is the stock or butt of the revolver, B is the cartridge-cylinder thereof, C is
the barrel, D is the trigger, E is the breech-block, OO are the aforesaid grooves
on the surface of the cylinder.
d is the trigger-stem, and is a circular projection on it which engages with the
aforesaid grooves. This lug or projection may be a part of the trigger-stem
itself, or a stud may be screwed into the trigger-stem to form the projection, as
represented in Figure 1. The shape and position of the grooves is such that when
the trigger is released after firing, about half of the amount of rotation necessary
to bring a second chamber into alignment with the barrel takes place during the
outward or forward motion of the trigger. On this account, the normal position
of the cylinder is one in which the two cartridge-chambers nearest the barrel are
t about equal distances on each side of the centre-line of the barrel.
I prefer to have the rear ends a of the grooves parallel to the axis of the
ylinder, so that during the last part of the motion of the trigger the cylinder will
ot rotate, but will be held in the correct position for firing.
The design of the grooves will be more clearly understood by a reference to the
Figure or Diagram 2.

page_text: In this figure or diagram the lines ff, f¹f¹ show the direction of motion of the
lug or projection d' of Figure 1, relatively to the grooves, this lug d¹ being repre-
sented in the diagrammatic Figure 2 by dotted circles q', g².
As will be seen from Figure 2, the meeting point e' of the rear edges of the
grooves o¹ and 02 is in such a position relatively to the space o8 that when the
lug (or its diagrammatic representation g¹) moves along the line ff, it will
pass below the aforesaid meeting point e¹, and engage with the rear edge of the
groove o If the surface of the cylinder is not allowed to have motion in any
direction but that at right angles to the lines ff and fi fl, it will be readily seen
that the surface of the cylinder will be forced upward in the direction of the arrow
as the circle g¹ moves along the line ff..
The meeting point of the forward edges of the grooves o² and o³ is also placed
in such a position relatively to the space a² that when the aforesaid lug (or its
diagrammatic representation g) moves along the line f¹ f¹, it will not enter the
groove o², but engage with the forward edge of the groove o³. And so on with
all such meeting points e, i, e², 2ª.
It is easily seen that in consequence of this arrangement of the grooves the
process of firing the revolver will cause the cylinder to rotate always in the same
direction.
The operation of this mechanism is as follows:-
On pulling the trigger the lug d¹, Figure 1, engages with one of the grooves
on the cylinder and causes the cylinder to rotate. When the trigger has nearly
completed its motion the lug di has arrived at a junction of two grooves, and
enters one of the short grooves a which is parallel to the axis of the cylinder and
to the line of motion of the trigger. The cylinder is therefore now at rest, and held
by the lug so that one of the cartridge-chambers is in alignment with the
barrel. The completion of the movement of the trigger fires the revolver. On
releasing the trigger the lug d moves forward, but, as has been shown by the
diagrammatic Figure 2, the position of the meeting points such as i of the forward
edges of the grooves is such that the lug d' will not re-enter the groove along which
it travelled while the trigger was being pulled, but will engage with the adjacent
groove and thereby cause the cylinder to rotate in the same direction as it did
during the pulling of the trigger. Finally, when the lug is back in its normal
position shown in Figure 1, that is to say, at the forward end of the grooves, the
cylinder has rotated about half the amount necessary for bringing another
cartridge-chamber into position for firing, and is in its normal position.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
In a repeating firearm having a revolving cartridge cylinder and in which the
trigger has a rectilinear motion parallel or very nearly so to the cylinder axis, a
projection on the trigger-stem engaging with grooves on the cylinder for the
purpose of rotating the cylinder, and substantially as described.
820
1000