IMPROVED LOCK MECHANISM FOR REVOLVERS
Year: 1885

page_text: COMPLETE SPECIFICATION,
I, GUSTAF ENVALL, of Linnégatan No 20, Stockholm, Sweden, Major in the
Swedish Army, do hereby declare the nature of said invention- for "IMPROVED
LOCK MECHANISM FOR REVOLVERS" and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
In the automatically cocking revolvers hitherto in use, it has been necessary
before taking aim to bring them to full cock with the thumb as in ordinary pistols,
in order to ensure a good aim. With rapid firing, however, when there is no time
of cocking beforehand, the cocking must be done and the shot fired by a single pull
of the forefinger. Under these circumstances the main spring offers a great
resistance, and the finger having to travel a distance of 13 to 14 millimetres the
pull must be effected almost instantaneously and a trembling of the weapon can
scarcely be prevented. It is often remarked that at very short distances persons
fire successively several times without making a hit or only occasioning a slight
wound.
The object of this invention is the production of a lock mechanism affording
greater accuracy, particularly in rapid firing, by the use of two triggers, one under
the revolver, whereby the weapon is cocked but by which it cannot be fired, and
another at the top whereby the shot is fired by the thumb. This mode of
operation has the advantage that the revolver is not brought out of position at the
very moment of firing.
On the accompanying sheet of drawings Fig 1 represents a side view of the lock
and the rear part of the revolver with the side plate and cheek taken away, the
revolver being safety cocked. Fig 2 represents a side view of the lock or the
mechanism with the side-plate removed, the hammer being brought to the full
cock. Fig 3 is a plan. Fig 4 is a cross section in front of the hammer a and the
spanner n showing them when brought to the full cock. The other figures
represent details of the mechanism, Fig 5 represents, viewed from two sides, the
pawl v, by which the revolver drum is turned. Fig 6 is a top view and a side
view of the catch x. Fig 7 is the fore part of the undermost arm a¹ of the main
spring, viewed from above. Fig 8 represents a side view of the hammer a and
Fig 9 a front view of the same. Figs 10, 11 and 12 represent the moveable parts
of the hammer removed, viz, Fig 10 the tongue d, Fig 11 the lever b, each shown
from two sides and Fig 12 a front view of the main spring link h. Fig 13 is a
front and side view of the spanner proper n and Fig 14 a side and top view of the

page_text: arm p of the spanner. Fig 15 is a side view of the trigger i seen from without;
Fig 16 is a section of the same along the line I, I of Fig 15. Fig 17 is the same
seen from above and Fig 18 the same from the inner side. Fig 19 is a side view
of the side plate and Fig 20 the same in section along the line II-II of Fig 19.
Similar letters of reference indicate corresponding parts in all the figures.
In this lock mechanism the hammer a is provided with a lever b passing through
a hole in the hammer and pivotted at c. The shorter arm of this lever is situate
below a backwardly projecting tail of the tongue d; the longer arm is provided
with a tappet e projecting from the end of the comb of the cock, and also with a
projection extending a little outside the inner rounding of the comb. The
hammer is further provided with a shoulder or rounded surface g at the one side.
The main spring link h, embraced by the top arm all of the main spring, is
extended downwards.
The trigger i situate at the top of the butt, is pivotted at k and actuated by the
spring and kept in position by the downwardly bent end of the plate m (shown
by the dotted lines in the Fig 17).
The spanner n, pivotted on the pin o, the arm p of which is pivotted thereon, is
provided with a stop 8, which by encountering a fixed part of the revolver body t
limits its motion. On the spanner n is the pawl v pivotted on its pin u, by which
pawl the drum (not shown on the drawing) is turned round. wis a shoulder, which
at the full cock, falls in a slot in the drum, thus fixing it.
a is a catch, which actuated by a little spring y, is pressed into the slit z on the
spanner when the hammer is brought to the full cock.
The mechanism works in the following manner: In order to cock the hammer,
the arm of the spanner is pulled back with the forefinger (or the middle finger)
whereby the spanner proper n pivots on the pin o until the stop s encounters the
lower edge of the revolver body and the catch a is pressed into the slit z. The
spanner n is now locked by the catch and the stops and the hammer has been
brought to the full cock as shown in Fig 2. The pawl v has meanwhile turned the
drum the requisite angle, and the shoulder w of the spanner fixes the drum in the
usual manner.
Now a sure aim being taken, the firing is effected by pressing the trigger i
downwards by means of the thumb. The trigger actuates then the lever b and
this turns the tongue d from its support against the spanner n and the upper arm a¹
of the main spring causes the hammer to fall down. On falling, the shoulder g on
the hammer presses the catch a out of the slit z of the spanner n, which becomes
free.
When the shot has been fired, but not before, the forefinger lets off, when the
bottom arm all of the main spring reposing upon the pawl v brings back the
spanner into its former position (see Fig 1). At the same time the shoulder 6¹ of
the main spring arun a glides along the curved surface c¹ of the downwardly
extending part of the main spring link and presses the hammer to the safety
bend (shown in Fig 1).
If, after cocking, the shot is not to be fired, the hammer may be let down in the
usual manner with the thumb by pressing in the projection f. The hammer moves
then automatically into the safety position.
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. The use in a revolver of a lock mechanism in which the hammer is spanned
and locked at full cock by pulling the arm of the spanner backwards by the fore-
finger and the firing is effected by pressing the thumb on a trigger situated at the
top of the butt, substantially as described
2. In a revolver mechanism such as referred to in the previous claim, the use of
the hammer a provided with a lever b, whereby the moveable tongue d can be
moved and with a shoulder or plane g for the catch a substantially as described.

page_text: 3. In a revolver mechanism such as referred to in the first claim the use of the
moveable trigger i kept in position by a spring, which trigger acting through the
lever b of the hammer, turns the tongue d from its support against the spanner n
substantially as described.
4. In a revolver mechanism such as referred to in the first claim the use of the
moveable catch which in cocking the hammer is pressed by a spring y into the
slit of the spanner n thus locking it, and which in letting down the hammer, is
brought out of the slit by means of the shoulder g on the hammer substantially as
described.
5. In a revolver mechanism such as referred to in the first claim the use of the
spanner n with the stop 8 the slit 2 and the arm p substantially as described.
6. The improved revolver mechanism, constructed, arranged and operating
substantially as described with reference to the drawings.
Dated this 15th day of May 1885.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Applicant's Agent.