RESER Compressed Air Engines for Working Pumps and for other Purposes.
Year: 1886

page_text: Date of Application, 19th May, 1886.
Complete Left, 26th Jan., 1887.
Complete Accepted, 1st Mar, 1887.
RESER
Compressed Air Engines for Working Pumps and for other
Purposes.
I JOHN HADFIELD STREET of No. 55 Woodlands Street Smethwick in the County
of Stafford Engineering Draughtsman do hereby declare the nature of this Invention
to be as follows:-
My invention is especially applicable to direct acting steam pumps and has for its
object to remedy the uncertainty of action attendant on steam pumps having tappet or
shooting valves.
My invention however is also applicable to compressed air engines for working
direct acting pumps as well as to steam or compressed air engines for other purposes."
I will describe my invention in connection with a steam engine.
I employ two slide valves one working on the face of the cylinder this I will call
the cut-off valve. The other valve which I will call the distributing valve works on
the back of the cut off valve.
The said valves have the following motions which motions are effected by the
mechanism hereinafter described.
When the piston has arrived say at the front or cover end of the cylinder the
distributing valve is brought to such a position on the cut off valve that there is a
slight lead or opening of the steam port through which steam passes to the front of
the piston thereby cushioning the piston and also starting it on its return stroke.
During the motion of the distributing valve the cut off valve is stationary and during
the motion of the cut off valve the distributing valve is stationary. The lead described
when the cut off valve approaches the front end of the cylinder is effected by the
motion of the cut-off valve on the stationary distributing valve. As the piston
commences its return stroke the distributing valve commences a reverse motion
continuing the said motion during the greater part of the piston's stroke.
As the piston gets near to the back end of the cylinder the cut off valve is set in
motion the distributing valve becoming stationary, and the action of the valves herein

page_text: before described when the piston is near the front end of the cylinder is repeated by
those parts of the valves situated at the back end of the cylinder.
The described motions of the valves are effected as follows:-The piston rod carries
an arm or bracket which through a connecting link or links gives motion to a lever
turning on a centre on the spindle of the cut off valve at a distance from the centre of
the said lever equal to about one third of its length another link is jointed to it
which link connects the lever described with the long arm of another lever turning on
a fixed centre. The short arm of this second lever is connected by a link to the end
of the spindle of the distributing valve. As both valves are under pressure of the
steam and the frictional area of the cut off valve is greater than that of the distributing
valve any pressure tending to move both valves first acts on and moves the distributing
valve. The said pressure when the motion of the distributing valve is arrested
produces motion in the cut off valve.
The action of the parts last described is as follows :-
The piston moving from the front end of the cylinder the arm carried by its rod
produces motion in the same direction in the first named lever this by the connection
described produces motion in the same direction in the long arm of the second lever
and consequently motion in a contrary direction in the short arm of the second lever.
When by the motion of the said short arm of the second lever the spindle of the
distributing valve has been drawn a certain distance its motion is arrested by a stop
and the further motion of the first named lever now operates upon the spindle of the
cut-off valve and produces the required motion of the said valve.
From the description given it will be seen that the motions of the valves are
always in a direction opposite to the motion of the piston.
Motions of the kind described but in a reverse direction take place in the valves
and gearing when the piston commences moving from the back towards the front end
of the cylinder.
W. T. WHITEMAN,
Agent for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in the Valves and Valve Gearing of Steam and
Compressed Air Engines for Working Pumps and for other
Purposes.
I JOHN HADFIELD STREET of No. 55 Woodlands Street Smethwick in the County
of Stafford Engineering Draughtsman do hereby declare the nature of my 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 is especially applicable to direct acting steam pumps and has for its
object to remedy the uncertainty of action attendant on steam pumps having tappet or
shooting valves.
My invention however is also applicable to compressed air engines for working
direct acting pumps as well as to steam or compressed air engines for other purposes.
I will describe my invention in connection with a steam engine.
I employ two slide valves one working on the face of the cylinder this I will call
the cut off valve. The other valve which I will call the distributing valve works on
the back of the cut off valve.
The said valves have the following motion which motions are effected by the
mechanism herein after described. When the piston has arrived say at the front or
cover end of the cylinder the distributing valve is brought to such a position on the
cut off valve that there is a slight lead or opening of the steam port through which
steam passes to the front of the piston thereby cushioning the piston and also starting
it on its return stroke. During the motion of the distributing valve the cut off valve
is stationary and during the motion of the cut off valve the distributing valve is
stationary. The lead described when the cut off valve approaches the front end of the
cylinder is effected by the motion of the cut off valve on the stationary distributing
valve. As the piston commences its return stroke the distributing valve commences a
reverse motion continuing the said motion during the greater part of the piston's
stroke. As the piston gets near to the back end of the cylinder the cut off valve is set
in motion the distributing valve becoming stationary and the action of the valves
herein before described when the piston is near the front end of the cylinder is
repeated by those parts of the valves situated at the back end of the cylinder.
The described motions of the valves are effected as follows:-The piston rod carries
an arm or bracket which through a connecting link or links gives motion to a lever
turning on a centre on the spindle of the cut off valve. At a distance from the centre
of the said lever equal to about one third of its length another link is jointed to it
which link connects the lever described with the long arm of another lever turning on
a fixed centre. The short arm of this second lever is connected by a link to the end
of the spindle of the distributing valve. As both valves are under pressure of the
steam and the frictional area of the cut off valve is greater than that of the distributing
valve any pressure tending to move both valves first acts on and moves the distributing

page_text: valve. The said pressure when the motion of the distributing valve is arrested
produces motion in the cut off valve.
The accompanying Drawing represents in longitudinal vertical section the steam
cylinder and piston of a direct acting horizontal steam pump to which cylinder valves
and valve gearing constructed and arranged according to my invention are applied.
d is the steam cylinder and the piston c² is the piston rod a, b are the two slide
valves the cut off valve being marked a and the distributing valve b. e is the steam
chest in which the valves a and b work. The cut off valve works on the face of the
cylinder d and the distributing valve 6 upon the back of the cut off valve a; a² a² are
the steam ports in the cut off valve a and a³ a³ are the exhaust ports in the said
valve a. The distributing valve consists of end parts for opening and closing the
steam ports a², a² of the cut off valve a and the middle bridge portions for opening
and closing communication between the exhaust ports a³, a³ and the exhaust passage in
the casing of the cylinder. The distributing valve 6 and cut off valve a move in a
direction opposite to that of the piston c and when the distributing valve is moving
the cut off valve a is stationary and the reverse as herein after fully described. at is
the spindle by which the cut off valve a is worked and 2 is the spindle by which the
distributing valve is worked. On the spindle 62 are stops and for the purpose
hereinafter explained. It will be seen that the frictional area of the cut off valve a is
greater than that of the distributing valve hence any pressure tending to move both
valves first moves the distributing valve.
The cut off valve a and distributing valve have the following motions given to
them by the gearing or mechanism which I will herein after fully explain.
Assuming the piston c and valves a, b to occupy the positions represented in the
drawing it will be seen that the piston c is situated at the front or cover end of the
cylinder d and the distributing valve has been brought into such a position that
the right hand portion of the said valve & slightly leads or opens the steam port a² at
the right hand end of the cut off valve a through which port steam passes to the front
of the piston c thereby cushioning the said piston and also starting it on its return
motion. This slight opening or lead of the cut off valve a as it approaches the front
end of the cylinder d is effected by the motion of the said cut off valve a against the
stationary distributing valve bas herein after explained. On the piston c commencing
its return stroke in the direction of the arrow the distributing valve b commences a
reverse motion in a direction contrary to that in which the piston c is moving the said
reverse motion of the distributing valve 6 continuing during the greater part of the
piston's stroke. As the piston e approaches the back end of the cylinder & the
distributing valve comes to rest and the cut off valve a is set in motion in the same
direction as that in which the distributing valve b has moved so as to give a slight
lead to the steam port at the back end of the cylinder as before explained with respect
to the front end of the said cylinder.
I will now describe the gearing or mechanism for operating the two valves a and b,
On the piston rod c² is an arm or bracket partaking of the motions of the said
piston rod is a lever the lower end of which is connected by the link to the
reciprocating arm or bracket f. The upper end of the lever turns on a centre i on
the spindle at of the cut off valve a. The spindle a of the valve a is connected to the
sliding block a working on the fixed framing of the engine. To the lever the
link is jointed the joints of the said link k also constituting a centre on which
the said lever turns during a portion of the stroke of the piston as herein after
explained. The outer end of the link k is jointed to the longer arm of the lever 1, n
the said lever, n turning on the fixed centre m. The short arm n of the said lever 1, a
is connected by the link to the end of the spindle 62 of the distributing valve b.
The action of the parts last described is as follows. On the piston c moving from the
front end of the cylinder d in the direction indicated by the arrow on the said
cylinder the arm carried by the piston rod c² produces motion in the same direction
in the lever the said lever turning on the centre i and no motion is imparted to the
valve rod a and cut off valve a until the lever has described the arc, a.
The
motion of the lever gives motion through the link or connection in the same

page_text: direction to the long arm of the lever 1, n and consequently motion in a contrary
direction as indicated by the arrow to the short arm n of the said lever 1, n. By the
motion of the link p and short arm n in the direction indicated by the arrow the
distributing valve b moves in that direction upon the stationary cut off valve a. By
the time the lever has described the area the stop has come in contact with the
fixed framing and is brought to rest. The lever can no longer turn upon the
contre i and the motion now communicated to the longer arm of the said lever h by
the arm causes the said lever to turn upon the centre s. The centre is thereby
moved to the right and the requisite motion produced in the spindle at of the cut off
valve a against the stationary valve the lower end of the lever now travelling in
the area. Thus while the lever his turning on the centre i the cut off valve a is
stationary the distributing valve moving upon the stationary cut off valve a during
the greater part of the pision's stroke the arresting of the motion of the distributing
valve by the stop causing the lever h to turn on the centres and the now upper
short arm of the lever to give the requisite motion to the spindle a for advancing
the cut off valve a against the stationary distributing valve & sufficiently far to reverse
the ports in the cylinder and effect a slight lead or opening in the steam port a² at
one or other end of the cylinder.
Motions of the kind described but in a reverse direction take place in the valves and
valve gearing when the piston commences moving from the back towards the front
end of the cylinder d the stop 72 now operating in the manner described with respect
to the stop r.
The valves and gearing described and represented have the advantage over the
ordinary tappet mechanism in the respect that all the parts of my improved mechanism
are geared together and are incapable of the derangement inseparable from mechanism
in which the parts are detached.
Having now particularly described and ascertained the nature of my invention and
the manner in which the same is to be performed I declare that I claim as my
invention of "Improvements in the valves and valve gearing of steam and compressed
air engines for working pumps and for other purposes,"
First The combination with steam or compressed air engines of the cut off valve a
and the distributing valve b working upon the back of the said cut off valve the said
valves a and having the motions with respect to each other herein before described
and moving in a direction opposite to that of the main piston for the purposes and
substantially as herein before described and illustrated in the accompanying Drawing.
Secondly The construction and combination of the parts of valve gearing herein
before described and illustrated in the accompanying Drawing for giving the requisite
motions to the cut off valve a and distributing valve b.
JOHN HADFIELD STREET.