Improvements in Direct Acting Steam or Fluid Actuated Motors, as used for Direct Acting Pumps, Rock Drills, and Reciprocating Movements of Pistons.
Year: 1899

page_text: Date of Application, 9th Jan., 1899-Accepted, 4th Mar., 1899
COMPLETE SPECIFICATION.
Improvements in Direct Acting Steam or Fluid Actuated Motors,
as used for Direct Acting Pumps, Rock Drills, and Reciprocating
Movements of Pistons.
I, RICHARD JAMES HODGES, of Cazenove Works, Dunstable, in the County of
Bedford, 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:
This invention relates to improvements in the method of operating the dis-
tributting valve in steam or fluid actuated motors as used for direct acting steam
pumps, rock drills, and reciprocating movements of pistons, the object being
to rapidly reciprocate the slide valve of such motor over the inlet and eduction
ports of the engine cylinder, so as to place the said ports in full communication
with the working pressure and exhaust alternately to, and from, each end of the
said cylinder with each forward and return stroke.
In the accompanying drawings my invention is shewn as applied to a direct
acting steam pump.
Fig. 1, is a longitudinal section shewing the valve chest in cross section on
line V, W, and
Fig. 2, is a cross section of the cylinder on line X, Y, shewing a longitudinal
section of the valve chest, and slide valve.
A is a slide valve of the ordinary D section having a flat face, BB are two
lugs projecting from the back of the valve and engage the assistant pistons CC',
D the valve chest is formed with a small cylinder at each end in which the
assistant pistons CC¹ reciprocate, the travel of which is equal to the desired
movement of the slide valve A across the main ports E, F, G.
The assistant cylinders inlet passages H, H', for pressure, are formed through the
pistons CC, and the exhaust ports I, II, are carried through into the main
cylinder, the main piston J is made somewhat longer than the stroke in order that
the exhaust ports I, I', are never uncovered by the ends of the main piston J.
Near each end of the main piston are recesses K, K', which open exhaust com-
munication between the assistant cylinder exhaust ports I, I, and the main
exhaust F alternately at each end of its stroke.
In operation; the pressure fluid entering the valve chest passes through both
passages H, H¹, but the passage I being full open to exhaust and passage I being
closed by the main piston, the assistant pistons quickly travel towards, and closes,
passage I, at the same time carrying over with them the main valve A, thus
admitting pressure to, O, end of the main piston J causing it to travel towards the
other end of its cylinder. Just before completing its stroke, recess K¹ opens
exhaust communicating between the assistant cylinder and main exhaust, through
passage I causing the pistons C & C to travel quickly to the exhaust end of the
assistant cylinder and carry over the main valve, thus reversing the flow of
pressure to the main piston and exhaust from the opposite end thereof. This
operation being alternately repeated when the main piston is at each end of its
гD 077

page_text: stroke, causes the main slide valve to automatically distribute pressure to, and
exhaust from, each end of the main cylinder alternately.
Should both the main ports be closed, with the main piston midway in the
cylinder, the slide valve can be moved by the wiper L and handle M.
my said
Having now particularly described and ascertained the nature of
invention, and in what manner the same is to be performed, I declare that what
I claim is:
1. In steam or fluid actuated motors, as used for direct acting pumps, rock drills,
and reciprocating pistons, a main distributing valve operated by assistant pistons
having small inlet pressure passages through them, exhaust passages leading from
the assistant cylinders to the main cylinder, and a passage in the centre of the
main cylinder leading to the main exhaust passage, and communication between
them being made alternately by the main piston when near each end of its
stroke.
2. In steam or fluid actuated motors, the arrangement of distributing valve,
assistant pistons, passages, main piston with recesses therein as described and
illustrated in the accompanying drawings and for the purpose set forth.
3. In an assistant cylinder, used as above described for the purpose of actuating
the distributing valve in fluid pressure motors, the exhaust passages many times
larger in size than the pressure inlets.
1
4. In assistant cylinder pistons, as above described and illustrated, small passages
leading from the pressure to the exhaust sides remaining open contantly.
5. The improved simple method for distributing actuating fluid in motors, such
as steam pumps, constructed, arranged and operating substantially as herein before
described and illustrated in the accompanying drawings.
Dated this 9th day of January 1899.
RICHARD JAMES HODGES.