Improvements in Partially Rotating Valves for Fluid Pressure Engines
Year: 1899

page_text: Date of Application, 8th Mar., 1899-Accepted, 8th Apr., 1899
COMPLETE SPECIFICATION.
Improvements in Partially Rotating Valves for Fluid Pressure
Engines,
I, WILLIAM VIVIAN, of Basset Road, Camborne, in the County of Cornwall,
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:―
In the Specification No. 15403 of 1898 is described a partially rotating valve
for governing the supply and exhaust of working fluid for the ends of a rock
drill cylinder.
The present invention relates to improvements in, the construction of valves
of the kind described in the said Specification which may be applied to fluid
pressure engines as will now be described with reference to the accompanying
drawings.
the
Fig. 1 is a plan of the valve box, Fig. 2 is a longitudinal section of the box
and valve. Fig. 3 is a transverse section on the line A-A, and Fig. 4 is a
transverse section on the line B B of Fig. 1. The valve box consists of a lower
part a with an upper part 6 secured on it by four bolts and nuts, and of two end
parts c and d secured on it by a central bolt and nut e. The end part & has a
pipe connection f for admission of the working fluid, and the end part d has a
pipe connection y for exhaust. In the inner face of the part c there is an annular
semi circular groove hand in the part da space, both of these facing semi-
circular grooves in the ends of the valve box, Q b. The valve k
is of cylindrical form fitted to partially rotate within the bore of
valve box. It has a central bore through which passes the
bolt there being annular space around e for passage of the working fluid to a
lateral port, on each side of which there is a recess m and n formed in the
valve. From the valve projects down a wing 2 the end of which fits against a
segmental hollow in the lower part of the valve box. From the middle of this
hollow fluid can pass by several small holes and a port o to the annular groove h
and thence by a channel à formed in the upper part of the valve box to the space i.
The channel has two lateral communications rs to ports facing the recesses. m
and .
In the lower part a of the valve box are two ports leading to the
two ends of the engine cylinder, and two ports and channels uw leading to lateral
ports of the engine cylinder corresponding with those marked and c in Fig. 4
of the drawings annexed to the Specification No. 15403 of 1898 above referred to,
so arranged relatively to a deep piston that when either is uncovered beyond
the end of the piston the other is open to a recess in the middle of the piston,
which recess coinmunicates by a lateral port marked f¹ in the said figure and a
passage with the exhaust space i.
The valve operates as follows:
The wing being at the one, say the right side, next the channel w the port-l
is then in line with the channel u and fluid passes by the port u to the right end
1
1 -ת

page_text: and port to q and thence to g; at the same time the cavity on the left of
communicates by the small holes and o with the annular groove h and by q to the
exhaust pipe g. At this time the port is in communication with the space in
the cylinder occupied by working fluid while the port w is in communication
with the exhaust recess of the piston.
When the piston in the cylinder uncovers the port leading to w. the port. v
being then in communication with the exhaust recess of the piston then the
working fluid acting on the wing p forces it to the left, so as to put in com-
munication with t, and u in communication with n and s.
The movement of the piston is thus reversed and the port leading to is again
covered, that leading to being still in communication with the exhaust recess
of the piston until it is covered by the piston. As the wing p is forced in either
direction past the small holes leading to o the pressure on it is reduced owing to
escape, of some of the fluid acting on it, and thus is avoided the shock which
would occur if p were driven over by full pressure acting on it during its whole
strokes.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I claim is
1. The partially rotating valve and box constructed and operating substantially
as described with reference to the drawings.
2. The ends of the valve box made with supply and exhaust branches respectively
and annular grooves in their inner faces and held by a single central bolt, sub-
stantially as described.
3. The valve made with central passage and lateral port for the working fluid
and with lateral recesses for exhaust; substantially as described.
4. The lioles and passage for exhaust from the wing cavity substantially as
and for the purpose set forth.
4
· Dated this 8th day of March 1899.
ABEL & IMRAY,
Agents for the Applicant.