Improvements in Fluid Pressure Motors.
Year: 1891

page_text: Date of Application, 12th Aug., 1891-Accepted, 12th Dec., 1891
COMPLETE SPECIFICATION.
Improvements in Fluid Pressure Motors.
We, HENRY KERRILL, of 80 Drumcondra Road, Dublin Plumber and
Engineer, and THE DUBLIN HYDRAULIC ENGINEERING AND MANUFACTURING
COMPANY LIMITED, North Great George's Street, Dublin, 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 :-
Our invention relates to fluid pressure motors, and comprises the improvements
hereinafter set forth and illustrated in the accompanying drawings which show
longitudinal central sections through the cylinders of two forms of our said
improved motors.
Referring to Figure 1 the cylinder C is provided with a double or compound
piston Q, the two parts of which are connected together by rods Q. The outlet
passage R is situated between the two pistons, and in order that the motive fluid
may flow freely to the exhaust we provide the following arrangements, that is to
say, we construct in each piston a conical central opening S, the larger end of
which looks outward or toward the near cylinder end. In each said opening we
fit a conical valve S and we rigidly connect the said valves together by a rod S²
which is of such a length that both valves cannot bed upon their seats at the same
time. When motive fluid is admitted to the cylinder at either end, the pressure
first operates to close the valve in the corresponding piston and thereby to open
the valve in the other piston so that when the compound piston begins to move,
there is a free passage for the escape of the motive fluid from the end of the
cylinder under exhaust through the valve in the piston and out at the exhaust
passage R.
We provide this cylinder with a controlling valve regulating the admission of
motive fluid.
The said valve comprises a small cylinder G provided with two pistons G²
mounted on a cominon piston rod or spindle G³ which projects through a suitable
gland in the valve cylinder cover. An inlet orifice G for the motive fluid is pro-
vided between the two pistons, and suitable outlet pipes F, F are provided leading
from near the ends of the valve cylinder to opposite ends of the motor cylinder.
The said pipes are alternately placed in communication with the inlet orifice by
the movement of the valve pistons in a manner well understood so as to lead the
working fluid alternately to opposite ends of the motor cylinder.
For actuating the controlling valve automatically so as to reverse the motion of
the motor piston at the completion of each stroke, and thus obtain a continuous
action, we provide a lever T pivoted at T and engaging at its outer end at T2 with
the spindle of the controlling valve. Its inner end projects through the cylinder
into the space between the two motor pistons and is actuated alternately by stops T³
as the pistons near the ends of their stroke. Or the said lever may be connected
to the motor piston at its inner end and moved backward and forward therewith,
the extent of movement being reduced at the controlling valve end to the desired
amount for actuating the valve, by suitably placing the pivot of the lever. A
suitable air vessel Jis attached to the inlet pipe to prevent excessive shock and to
prevent extreme variations of pressure upon the working parts. This engine may
have an internal crank and connecting rod arranged in the space between the two
pistons, the said crank being secured on a shaft that passes radially out from the
cylinder in a well known manner, or it may have a reciprocating piston rod Q³
passing out through one of the cylinder ends as shown, said piston rod being
attached to the piston by a bridge piece Q in such a manner as to allow of the
free movement of the valve S¹.

page_text: In the horizontal hydraulic motor shown in Figure 2 there are two cylinders C,
affixed to the bed plate A, each having a single piston Q. The pistons of the two
cylinders are connected together by two piston rods Q' to which à cross head Q2 is
attached, the motion being transmitted from the said cross head in any suitable
manner. We have illustrated the cross head as communicating motion to the
wheels U for example by connecting rods u and cranks V. The valve pistons G¹
in this example are operated from the cross head by a slotted bar W attached
thereto which operates the lever T. The functions and operation of the valve
pistons G2 and of the conical valves S, S' are the same as those of the corre-
sponding parts in Figure 1 but instead of a single exhaust passage R as in that
figure two exhaust channels R¹ are provided one for each of the cylinders. Into
the said channels the exhaust fluid flows from the open ends of the cylinders. The
said two exhaust channels communicate with a common exhaust outflow R. It
should be noted that the valve spindle S2 of the conical valves passes freely through
a hole S³ in the cross head so that it is not influenced thereby.
Our improved motor is advantageously worked by hydraulic power, but it may
be worked by compressed air or gas, or by steam.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
A fluid pressure motor constructed substantially as described with reference
to either of the forms herein described and illustrated in the accompanying
drawings.
Dated tms 24th day of CLODET 1031.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.