Improvements in or connected with Direct-acting Steam Pumping and other like Engines.
Year: 1889

page_text: Date of Application, 15th May, 1889
Complete Specification Left, 15th Feb., 1890--Accepted, 12th Apr., 1890
PROVISIONAL SPECIFICATION.
Improvements in or connected with Direct-acting Steam Pumping
and other like Engines.
I, WILLIAM HOLKER, of 19, Leece Street, Liverpool, in the County of Lancaster
Engineer, do hereby declare the nature of my said invention to be as follows:-
My Invention relates to that class of steam engines in which the valve is worked
by means of a rocking lever actuated by a tappet or crosshead during each in and
out stroke of the piston.
In carrying out my invention; I employ an ordinary slide valve, which is actuated
by a bell crank lever or rocker, worked by the crosshead which connects the steam
piston rod, with the pump or other piston rod, or by a collar, or other device, or
ineans, on the piston rod, I extend or project the bell crank lever or rocker below the
centre of the shaft it works upon, so that the slide valve will be closed by the action
of the crosshead at half stroke, thus the other half stroke of the steam piston is
worked expansively, I also form the bell crank lever, or rocker in such a way that
after the valve is closed the action of the crosshead will continue to move the lever or
rocker, until the whole of the lap of the valve is taken up, and where the crosshead
comes in contact with the ends of the lever or rocker, the lever is so formed as to
open the slide valve and give it the required lead. To open the valve full, each end
of the tell crank lever may be provided with a sliding projecting plate or equivalent
device, against which the crosshead comes on the return stroke. When the crosshead
comes in contact with this plate, or otherwise, it lifts the end of the bell crank lever
and opens the valve full at the commencement of the stroke, while at the end of the
stroke the plate slides out of the way and allows the crosshead to pass without moving
the lever. A spring or its equivalent being provided to bring the sliding plates back
to their place. I connect the piston rod of the steam cylinder to the piston rod of
the pump or other cylinder, by taper wedges which pass through slots in the ends
of the rods, and I form a slot or way in the centre of the crosshead so that by
driving a wedge into this slot or way, and between the ends of the rods I can
start or drive them out of the crosshead and remove the parts when required for
repairs.

page_text: the centre of the shaft it works upon, so that the slide valve will be closed by the
action of the crosshead at half stroke, thus the other half of the stroke of the steam
piston is worked expansively. I also form the bell crank lever or rocker in such a
way that after the valve is closed the action of the crosshead will continue to move
the lever or rocker until the whole of the lap of the valve is taken up, and where
the crosshead coines in contact with the ends of the lever or rocker the lever is so
formed as to open the slide valve and give it the required lead. To open the valve
full, each end of the bell crank lever is provided with a sliding projecting plate or
equivalent device, against which the cross head comes on the return stroke. When
the crosshead comes in contact with this plate it lifts the end of the bell crank-lever
and opens the valve full at the commencement of the stroke, while at the end of the
stroke the plate slides out of the way and allows the crosshead to pass without moving
the lever, a spring or its equivalent being provided to bring the sliding plates back to
their place. I connect the piston rod of the steam cylinder to the piston rod of the
pump, or other cylinder, by taper wedges which pass through slots in the ends of the
rods, and I form a slot or way in the centre of the crosshead, so that by driving a
wedge into this slot or way, and between the ends of the rods, I can start or drive
them out of the crosshead and remove the parts when required for repairs.
To ensure the engine working evenly, I have found it advisable to employ a fly
wheel in connection with the crosshead, to give momentum to the crosshead. I mount
the fly wheel loose on one end of the crosshead, and I provide a toothed pinion fixed
to the flywheel; this pinion travels in an internal continuous rack carried on the
engine frame and is free to slide up and down, so that this pinion will gear with
either side of the rack and give a continuous rotary motion to the fly wheel.
Having thus stated generally the nature of my Invention I will now describe it
with reference to the drawings hereto annexed, which form a part of this specification
and illustrate an example of a direct acting steam pumping engine with the improve-
ments according to my invention applied thereto. The drawings are marked with
letters and figures of reference corresponding with those used in the following
explanation, and like letters and figures are used to denote the same or corresponding
parts throughout the various views.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a side elevation of a direct acting steam pumping engine provided with
a rocking lover worked direct from the crosshead and according to my invention.
Figure 2 shows the position of the rocking lever when the engine crosshead is at
the end of the stroke and shows the position and lead of the slide valve at that time.
Figure 3 shows the position of the rocking lever when the slide valve is full open.
Figure 4 shows the position of the rocking lever when the crosshead is at half
stroke and the valve closed.
Figure 5 shews the position of the rocking lever when the crosshead is near the
end of its stroke and before giving lead to the valve.
Figure 6 is an end view of the rocking lever and the slide valve lever.
Figures 7, 8, 9, are details of the crosshead and piston and pump rods and means of
disconnecting the piston and pump rods.
Figure 10 is an elevation of a fly wheel and pinion and rack employed to give
momentum to the crosshead.
The following comprise the chief letters of reference used in the description of the
drawings, to designate the chief parts of the engine illustrated.
a is the steam cylinder; bis the pump cylinder; c is the guide frame; is the
crosshead is the valve; f is the valve spindle; g is the lever which works the
valve spindle; h is the shaft which carries the lever; is the rocking lever which is
also carried by the shaft ; is the steam cylinder piston rod; is the pump rod;
is the fly wheel; m is the fly wheel pinion; n is the internal rack.
In carrying out my Invention the slide valve e (which is of the ordinary kind) is

page_text: actuated by the rocking lever i so as to cut off steam at a certain part of the stroke of
the piston of the steam cylinder a, and thereby work the engine expansively. The
rocking lever i is worked by the crosshead & which connects the steam piston rod j
and the pump rod ; the lever is carried by and works on the shaft h, said lever
being of form to extend below such shaft, and having at its ends slots i, provided with
sliding plates retained by springs 13; these plates are set at an angle on the lever i
with their outer ends projecting; each end of the lever is provided with projections ¿+,
which in working give the lead to the valve, and the under surface and stroke of the
lever i is such that the slide valve e may be closed at half or any other part of the
stroke desired.
In Figures 2, 3, 4, and 5, the rocking lever i is set to work the valve e to cut off
steain at half stroke. Thus in Figure 2 the crosshend d is at the end of its stroke and
under the projection it, and has caused the lever i to give the valve e the required
amount of lead; as the crosshead & moves on its stroke, it comes in contact with the
projecting end of the sliding plate is and causes the lever i to take the position shown
in Figure 3, and to bring the valve e full open. As soon as the crosshead d passes
the centre of the lever the lever i takes the position shown at Figure 4, and the
valve e is moved back and is closed for the rest of the stroke, the sliding plate i at
the other end moving out of the way, on the cross head coming under the projection #,
the valve e is again given lead for the return stroke of the engine, when the same
action of the lever i and valve e is repeated on the return stroke of the crosshead d.
The crosshead at the end of the stroke passes under the plate 2 which moves up its
slide out of the way, the valve remaining closed as shown in Figure 5. The plates 12
on the lever i are brought back to their normal position by the springs is. It will be
seen, by the above movements of the crosshead d and the lever i, that after the valve
is closed at half stroke the action of the crosshead will continue to move the lever i
until the whole of the lap of the valve e is taken up, and when the crosshead comes
in contact with the ends the valve is opened to the extent of the required lead.
The piston rod and the rod are connected to the crosshead by cotters j¹ and
in the ordinary way, and as shown at Figures 7, 8 and 9, and to enable the rods to
be started from the crosshead d, I form a hole in the centre of the crosshead, at d¹,
so that by driving a wedge into this hole and between the ends of the rods j and k they
can be driven out from the crosshead when required.
P
I have above stated in describing the action of the slide valve e, as worked by the
lever, that the steam is used expansively. To ensure the engine working evenly I
provide the crosshead with a fly wheel, which may be arranged as shewn in
Figure 10 to run on the end of the crosshead. Attached to the fly wheel p there is
a toothed pinion; this pinion travels in an internal toothed rack S, which is carried
by the guide brackets tt, in which it is free to be moved up and down so that the
pinion will gear with either side of the rack and give a continuous rotary motion to
the fly wheel. The brackets t t are bolted to the engine frame and are provided with
levers at each end. The outer end of these levers u are connected to a rod v which
works a lever w, which works in an inclined loop fitted under the rack s.
To work
the levers there are provided rods, which pass through the ends of the racks, and
at the end of each stroke these rods are moved by the crosshead coming in contact
with one of them and thereby the levers u and rod v are worked and the rack raised
or lowered to meet the pinion r.
By the means above described and according to my Invention a direct acting steam
pumping or other like engine will work expansively as the rocking lever which works
the valve can be arranged to cut the steain off at any desired part of the stroke of
the piston. By working the engine expansively it can be constructed with a longer
stroke than is usual with this class of engine, and will work with greater econoiny
than a short stroke engine to which steam is given for the full stroke.
Although I have described my invention as applied to a horizontal engine I would
have it understood that it is equally applicable to vertical and other engines of the
direct acting type,

page_text: Having now particularly described and ascertained the nature of my said Inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The improvements substantially as herein described,connected with direct acting
steam pumping and other like engines, consisting in constructing and arranging the
rocking lever which works the valve of the steain cylinder so that it will close the
valve and cut off the steam at any desired portion of the stroke, as set forth.
2. In connection with engines of the type herein described, the means substantially
herein specified, whereby lead is given to the valve and a means provided, whereby
the steam is cut off at a portion of the stroke of the piston and the engine worked
expansively.
3. In connection with engines of the type herein described, a rocking lever for
working the valves, provided with a means for giving lead to the valve, opening the
valve full, and closing the valve at a portion of the stroke, so as to work the engine
expansively; and also the rocking lever constructed and operating as set forth with
reference to the drawings.
4. The improvements connected with direct acting steam pumping and other like
engines herein described, consisting respectively of the means for working the valve,
and the means for separating the piston and pump rods from the crosshead; sub-
stantially as set forth and shewn in the drawings hereto annexed.
Dated this 14th day of February 1890.
WILLIAM HOLKER.