Improvements in Pivots for Mountings of Heavy Guns.
Year: 1890

page_text: Date of Application, 20th Mar., 1890-Accepted, 3rd May, 1890
COMPLETE SPECIFICATION.
Improvements in Pivots for Mountings of Heavy Guns.
1, THOMAS ENGLISH of Hawley near Dartford in the County of Kent, Civil
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 invention relates to the construction of pivot for the mounting of a heavy gun
on a racer or racers in such a manner that during traversing, the weight of the
gun and its mounting is partially or entirely supported on liquid at the pivot, the
frictional resistance to the traversing movement being thus greatly reduced. I shall
describe an arrangement of pivot for this purpose referring to the accompanying
drawings. Fig. 1 is a side view partly in section and Fig. 2 is a plan shewing a
pivot according to my invention for the mounting of a heavy gun. On the top of
a standard or base A I fix a short hydraulic cylinder (fitted with a solid piston or
plunger B which is free to turn or rise in the cylinder but with sufficient closeness
of fit to prevent or impede the leakage past it of oil as viscid as is consistent with
its being pumped. The frame D of the mounting rests on the plunger B and is
bushed at D so that it can revolve around the cylinder C. On the frame D is fixed
an annular cistern E to receive such liquid as may leak past the plunger B, this
liquid flowing over a lip c of the cylinder. There is also fixed to the lower part of
the frame a cistern F communicating with E by a vertical passage f. Also on the
lower part of Dare fixed two force pump barrels in one piece G both of which draw
liquid through the same suction valve by a pipe y from the cistern F and discharge
the liquid through the same delivery valve by a pipe c¹ into the cylinder C. The
plunger h of one of the pump barrels can be worked when required by a hand lever H
and also, when desired by an excentric t, on the traversing shaft T, the excentric rod
being made with a gab at t engaging with a crank on the shaft of the lever H. By
means of a handle and lever the gab t can be disengaged from the pumping
crank. The plunger of the other pump barrel is connected to another excentric t
on the traversing shaft T, which, when the gun is traversed is turned by the winch
handle W. The relative angular set of the excentrics and 3 can be varied by
shifting a coupling. On the base of A is pivotted a lever arm a which near its
fulcrum is connected by a link a¹ to a bracket projecting down from the frame D;
farther from its fulcrum the arm a is connected by a link a² to a stem which ente:s
a hole in the lower part of the pump G and bears against the lower side of the
suction valve.
The gun and its mounting being as nearly as practicable balanced on the plunger B,
the apparatus is operated in the following manner. Before traversing, the pump
can be worked by the lever H forcing liquid into the cylinder C and slightly
raising the plunger, the mounting and the gun, so that the weight is as far as
practicable supported on the liquid in the cylinder.
The shaft T being then turned by the winch W for the purpose of traversing, the
pump plunger k is worked, also if the gabbe engaged, the plunger h. and thus
farther liquid is forced into C to make up for any leakage that may take place. The
amount required to effect this can be determined by trial and varied when required
by adjusting the relative angular positions of the excentrics and As the
mounting is raised by the liquid pressure, the arm a is also raised and the link a'
is raised to a greater extent until the stem at its top lifts the suction valve of the
pump from its seat whereupon although the plungers hand k may continue to
reciprocate, no farther liquid is pumped into C and consequently the mounting and
gun are no farther raised. A release valve can also be opened when desired by
means of the hand lever S, and the gun and mounting lowered on to the racers.

page_text: Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
In combination with the mounting of a heavy gun on racers a pivot consisting of
a short hydraulic cylinder and plunger and a pump or pumps for supplying the
cylinder with liquid such as viscid oil, worked by hand or by the traversing gear,
substantially as and for the purpose set forth.
Dated this 20th day of March 1890.
ABEL & IMRAY,
Agents for the Applicant.