A Device for Preventing the Displacement of Ordnance Sights by the Firing of the Gun.
Year: 1894

page_text: Date of Application, 3rd May, 1894
Complete Specification Left, 14th Jan., 1895-Accepted, 16th Feb., 1895
PROVISIONAL SPECIFICATION.
A Device for Preventing the Displacement of Ordnance Sights by the
Firing of the Gun.
I, HUBERT HENRY GRENFELL, of 18 Ashburn Place, in the County of London,
Captain Royal Navy, do hereby declare the nature of this invention to be as
follows:-
My invention relates to a clutch mechanism for preventing the displacement of
gun sights by the firing of the gun; that is to say, for preventing the downward
sliding movement of the adjustable sight bar which is apt to result from the
vibration caused by firing.
This mechanism comprises in the preferred form of construction two hardened
steel discs furnished with ratchet or similar teeth adapted to engage each other
and which operate to prevent the rotation of one disc with respect to the other in
one direction while allowing of rotation in the other direction. One of said
toothed discs is secured to the end cover or other stationary part of the sight body
and the other toothed disc is secured to the hand-wheel for raising and lowering
the sight bar. The said discs are maintained normally in gear by a spring con-
tained within the hand wheel aforesaid aud bearing against a collar mounted on the
spindle of the hand wheel. When it is required to lower the sight bar, the hand
wheel is drawn back so as to disengage the teeth of the aforesaid discs, where-
upon the hand wheel can be turned in the direction required. When the hand-
wheel is released, the toothed discs are caused to gear again with each other and
so lock the sight bar. The hand wheel is preferably connected with its spindle
by a pin which passes through a longitudinal slot in the boss of the wheel to allow
of the required sliding movement of the wheel above referred to, while ensuring
that the hand wheel and spindle when turned must turn together. On account of
the shape of the ratchet teeth on the discs it is not necessary to draw back the
hand wheel when it is required to raise the sight bar as the teeth slide over each
other when the wheel is turned in the direction for raising the bar.
Dated this 3rd day of May 1894.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
A Device for Preventing the Displacement of Ordnance Sights by the
Firing of the Gun.
1, HUBERT HENRY GRENFELL, of 18 Ashburn Place, in the County of London,
Captain Royal Navy, 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 invention relates to a device or mechanism for preventing the displacement
of gun-sights by the firing of the gun; that is to say, for preventing the downward
sliding movement of the adjustable sight bar that is apt to result from the vibration
caused by firing.

page_text: This device or mechanism comprises, in the preferred form of construction, two
hardened steel discs furnished with ratchet or similar teeth that engage with each
other and that while in engagement prevent the rotation of one disc with respect to
the other in one direction while allowing the rotation in the other direction. One
of the said toothed discs is secured to the eud cover or other stationary part of the
sight-body and the other toothed disc is secured to the hand-wheel for raising and
lowering the sight bar. The said discs are normally maintained in gear by a spring
contained within the hand wheel.
In the accompanying drawings,
Figure 1 is a central longitudinal section of my improved mechanism.
Figure 2 is an elevation of the hand wheel detached, looking in the direction of
the arrow Figure 1.
A is the end cover of the sight-body, B is the spindle for operating the sight bar,
C is the hand wheel for turning the spindle. D is a hardened steel disc secured
to the hand-wheel. It is furnished with a circular series of ratchet or like teeth D'.
E is another similarly toothed disc secured to the end cover A and having its teeth
engaging with those of the disc D. The hand wheel C is not fixed on the
spindle B but drives the same through a taper pin F that is secured in the spindle
and that projects through longitudinal slots C in the hub of the wheel. These
slots allow of an axial sliding movement of the wheel on the spindle.
G is a
spring placed around the spindle within the hub of the wheel and compressed
between the disc D and a collar H secured on the spindle by the pin F. This
spring operates normally to maintain the teeth of the disc D in gear with those of
the disc E. When it is required to lower the sight bar, the hand-wheel C is
drawn back so as to disengage the teeth of the aforesaid discs, whereupon the
hand wheel can be turned in the direction required. . As soon as the hand-wheel
is released it is pushed inward by its spring, and the toothed dises are thus caused
to gear again with each other and so lock the sight bar. By reason of the shape
of the ratchet teeth on the discs it is not necessary to draw back the hand wheel
when it is required to raise the sight bar as the teeth will slide over each other
when the wheel is turned in the direction for raising the bar.
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 :-
1. The device constructed substantially as described with reference to the
accompanying drawings for operating as, and for the purpose, specified.
2. The combination of the said device with a sight-bar substantially as and for
the purpose specified.
D
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.