Improvements in Bolt Action Breech Loading Firearms.
Year: 1896

page_text: Date of Application, 18th Apr., 1896-Accepted, 23rd May, 1896
[Communicated from abroad by ANDREAS WILHELM SCHWARZLOSE, of
212 Friedrichstrasse, Berlin, Empire of Germany, Armourer.]
Improvements in Bolt Action Breech Loading Firearms.
I EDWARD TURNER WHITELOW of 70 Deansgate, Manchester, Consulting
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:-
My said invention relates to improvements in fire arms having a cylindrical
breech bolt.
In many such fire arms as hitherto constructed the engagement of the breech
bolt with the barrel is effected by front lugs or projections on the breech bolt
which guided in longitudinal grooves in the breech sleeve only come opposite
corresponding catches of the breech sleeve on the breech bolt turning to the
right.
This mode of closing the breech renders it possible to relieve the breech sleeve
and also the greater part of the breech bolt from the pressure of the gases resulting.
from the explosion and thus by reducing the strength of the breech sleeve and the
breech bolt the weight of the weapon can be reduced without detriment to its.
efficiency. At the same time a greater precision of fire is gained as compared
with the method of locking by for example the chamber guide bars sometimes
used.
By the use of such a mode of locking the breech is however lengthened because
space must be provided between the cartridge magazine and the barrel for the
introduction in the breech sleeve of the parts which receive the front lugs of the
breech bolt and therefore in order to open the breech the bolt must be drawn much
farther back than the length of the cartridge would otherwise require.
drawback is particularly evident in automatic fire arms where the pushing forward
of the breech bolt must be accomplished by special springs.
This
The object of my said invention is a new breech locking system which obviates
the above mentioned disadvantage and while increasing the ballistic capacity of the
arm to which it is applied simplifies the construction and manufacture."
In the accompanying drawings which illustrate my said invention and to which
reference is hereinafter made
Fig. 1 is a cross section through of Fig. 2.
Fig. 2 is a longitudinal sectional elevation through the front part of the breech.
sleeve.
Fig. 3 is an end view of the breech bolt.
Fig. 4 is a side view of part of the breech bolt.
Fig. 5 is a transverse section through the closed breech system.
In the breech sleeve H immediately behind the opening into the barrel L are two
diametrically opposed breech lugs w w corresponding to which are formed two
short longitudinal passages n n in the end of the breech bolt C or on the head
connected therewith. The passages n n open into a cross groove n at right angles
to the passages n n which are so arranged as that on the advance of the breech
bolt they slide along the lugs wow of the breech sleeve. If now as soon as the
breech bolt or the breech head is up to the barrel the breech bolt is turned through
an angle of 90° to the right the cross groove a¹ engages with the breech lugs w 20,

page_text: so that their flat faces lie against each other and the breech being closed they
receive the force of the recoil (see Fig. 5).
Although only two breech lugs are shown it is to be understood that any desired
number may be used alongside or behind each other. The lateral arrangement of
the breech lugs in the breech sleeve allows the cartridge magazine to be brought
direct behind the barrel so that the breech bolt need only be drawn so far back as
the length of the cartridge necessitates. Owing to the surfaces which effect the
locking lying nearer to the axis of the barrel than is the case where the locking
lugs are on the breech bolt the distance apart of the lugs need only be slightly
greater than the diameter of the base of the cartridge so that the play of the
breech bolt behind the base of the cartridge due to compression and bending on
firing may be diminished. The precision of the arm is thereby enhanced owing to
the lessened vibration of the surface which receives the shock. In addition to this
the longitudinal grooves in the breech sleeve (to receive the lugs of the breech
bolt in the old construction) are eliminated and thus the breech shell may be
lightened while retaining the same effective area in cross section and being easier
to construct.
Injury to the user by a backward escape of the gases is prevented owing to the
breech bolt completely closing the bore of the breech shell.
In order to provide space for the harmless exparsion of the gases in the event
of a cartridge case bursting I provide a space c between the rear end of the barrel
and the front end of the breech bolt (Fig. 5).
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.―
A breech locking device consisting of the combination of the breech_bolt (or
bolt head) C having a cross groove n¹ longitudinal passages n at right angles
thereto leading therefrom to the front and the breech sleeve H having internal
breech lugs w corresponding to the passages n n' and adapted to engage therewith
substantially as and for the purpose set forth and shown.
Dated this 17th day of April 1896..
E. T. WHITELOW.