Improvements in Field-gun Carriages.
Year: 1890

page_text: Date of Application, 28th Feb., 1890-Accepted, 17th May, 1890
COMPLETE SPECIFICATION.
Improvements in Field-gun Carriages.
I, 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 carriages for field guns as will be
described ieferring to the accompanying drawings.
The gun is allowed to slide backwards on recoil in straight guides formed in a
cradle pivotted horizontally and vertically by a universal joint on the axletree of
the carriage.
The recoil in the cradle is controlled by an oscillating hydraulic buffer, of
which the cylinder is pivotted to the cradle and the piston rod is pivotted to the
gun, the piston rod and gun being brought back to the firing position by means of
a spring.
Figure 1 of the drawings is a side elevation of the carriage with the gun in the
firing position.
Fig. 2 is a plan of the carriage with the gun removed, and
Fig. 3 is a part transverse section on the line A B Fig. 1 partly, in elevation.
a is the axletree of the carriage of tubular steel of varying diameter and of circular
section except where it passes through the trail brackets bb at which part it is
octagonal in section. The axletree a is surrounded between the trail brackets by
sleeves capable of partial rotation, on it.
a
The outside of this sleeve is provided above and below with vertical pivots p. p
thus forming a universal joint for the front end of the cradle cc which carries
the gun.
The rear end of the cradle cc is supported on the elevating screw e which is
carried by a nut n¹ revolving in a bearing, as shewn in Fig. 3, and is actuated
through a pair of bevil wheels by a hand wheel h.
The bearing of the elevating nut is prolonged laterally in both directions to form
sliding trunnions which are supported in the trail brackets b b. One of these
trunnions t¹ is hollow and is provided with an internal screw thread which engages
with the screw shank of a hand wheel w which is carried in a bearing projecting
from the trail bracket b. By turning this hand wheel in either direction the elevating
nut and screw together with the cradle and gun can be traversed laterally, the
whole system pivotting round the vertical pivots p p of the universal joint already
described. By turning the hand wheel the gun can be elevated or depressed
about the same joint.
с
The upper part of the cradle c is provided with two pairs of longitudinal guides
and, the front pair of guides 1 embrace ribs formed either on the gun itself, or as
The rear
shewn on the carrier z.attached to it, and support the weight of the gun.
pair of guides. 1 are embraced by a sliding piece q connected with the gun by a
pin q passing through a hole formed in the metal of the part of the gun below the
breech.
An bydraulic buffer cylinder. m lying between the gun and the cradle, is secured
by trunnions c¹ to the latter and is filled with liquid such as oil, and provided with
a solid piston. The. piston rod n projects through both ends of the buffer cylinder
and is coupled at its rear end to the horizontal pin ql, the part of the piston rod n
which projects through the front end of the cylinder, carries a nut and is surrounded
by two helical volute springs o o set base to base, which on récoil are compressed
between the nut and the front end of the cylinder m and on recovering their shape
after recoil, draw the piston rod and gun back into the firing position; sufficient

page_text: :
clearance is provided between the solid piston and the internal surface of the
cylinder m to allow of the transfer of the liquid from one side to the other of the
piston, and the bore of the cylinder m is made conical, and largest at the front end,
so as to cause the resistance of the fluid to the motion of the piston to be
approximately uniform during recoil.
carried
The brake consists of two wooden blocks faced with leather or other suitable
material f, one for each wheel, which are held on the extremities of levers
by a horizontal shaft i passing through the trail brackets 6 transversely to the
carriage. Connecting rods g¹ coupling the brake blocks f to the bearings of the
shaft serve to keep the brake blocks approximately concentric with the wheel
during the partial rotation of the shaft. The bearings are supported by stays 22
from the body of the carriage and from the axletree. The shaft is divided in the
centre, the two halves being coupled by a compensating leverjj engaging at its ends
with a pin secured to each half of the shaft i and at its centre with a pin forming
part of a sleeve & surrounding i.
This sleeve is slotted to allow the pin at to pass through it and is capable of
partial rotation on a bearing in the trail bracket b.
The part of which projects beyond the trail bracket being shaped as a lever k¹
by pulling which the sleeve k, the compensating lever jj and the shaft i are made to
revolve together and thereby press the brake blocks ff with equal force against
the wheels.
The pull on the lever k¹ is communicated through a spiral spring connecting rod r
giving sufficient elasticity to allow for irregularities in the circumference of the
wheels.
The rod is attached to a lever u formed on one end of a shaft u u¹ which is
supported by bearings in the trail brackets b b and carries a ratchet sector v engaging
with a pawl o' which serves to hold the brake on after it has been applied either by
hand or automatically, and can be thrown out of gear by a hand lever v1.
The brake is applied automatically by the recoil of the gun causing the backward
motion of the pin q', at the extremity of which is a spherically countersunk hole,
through which slides the connecting rod x.
The rear end of the connecting rod behind the pin q¹ is formed as a spherical head
which can seat itself in the hole of q' forming a ball and socket joint. The front end ¹
of the connecting rod x is attached by a ball and socket joint to a projection of the
ratchet sector and by this means the backward motion of the gun and pin ql is
communicated through the shaft and lever u ul and the rod r to the brake lever k¹
thus putting on the brakes which are kept on after the return of the gun to the firing
position by the pawls vl until released by the hand lever v when the brake mechanism
is returned to its normal position (as is shewn on the drawing) by the pull of a spiral
spring y attached to the compensating lever jj and the cross shaft u which spring is
extended when the brakes are put on.
The brakes are put on by hand when required by the hand lever ull which is
furnished with claws engaging the end of the shaft u u¹ these claws being so shaped
that the hand lever is left at rest when the brake is automatically applied, whilst, on
the hand lever being lifted, they cause the rotation of the shaft u u¹ and the applica-
tion of the brake, the connecting rod xx¹ in this case sliding back through the hole
in the pin q
As a modification of the mechanism actuating the brake, in some cases I substitute
for the compensating lever j j', the sleeve and lever k k¹ and the elastic connecting
rod r, an elastic lever composed of a plate spring lying transversely to the carriage,
connected at its ends to the pins on each half of the shaft i and at its centre by a
rigid connecting rod to the lever u.
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 :-
1. In a field gun carriage, mounting a cradle carrying the gun by trunnions on

page_text: a sleeve which can turn on the axletree so as to form a universal joint, in combina-
tion with oscillating and transversely sliding trunnions for the nut of the elevating
screw, substantially as described.
2. In a field gun carriage, a brake applied automatically to the wheel tyres by the
recoil movement of the gun in its cradle, substantially as described.
Dated this 28th day of February 1890.
ABEL & IMRAY,
Agents for the Applicant.