Improvements in Pumps for Oil Engines or other purposes.
Year: 1894

page_text: Date of Application, 12th May, 1894
Complete Specification Left, 12th Feb., 1895--Accepted, 6th Apr., 1895
PROVISIONAL SPECIFICATION.
Improvements in Pumps for Oil Engines or other purposes.
1, WILLIAM HARDING SCOTT, Gothie Works, King Street, Norwich, Electrical
Engineer do hereby declare the nature of this invention to be as follows:-
My invention applies to pumps the capacity of which it is desirable to vary
without altering the speed or varying the stroke.
I vary the capacity of the pumps by providing means whereby the liquid can be
returned during part of the stroke of the pump to the suction pipe or its equivalent,
and to do this I make a hole or holes in the side of the pump cylinder communicating
with the suction in such a position that at a certain part of the down stroke in a
vertical pump the pump plunger or an extension of it covers up the hole or holes ;
then the communication between the suction pipe and the inside of the pump being
closed the liquid is forced through the delivery valve. Now by suitably shaping
the part of the plunger that covers the hole or holes in the side of the pump
cylinder I arrange so that by revolving the plunger through part of a revolution I
can close the hole or holes at an earlier or later part of the stroke and by having
the pump plunger hollow part way up and by cutting away part of the sides of the
hollow plunger a little higher up than the part that closes the hole or holes in the
pump cylinder I can arrange so that as the plunger goes down it opens the hole or
holes into the suction so that only the centre portion of the stroke is used and by
shaping the part of the plunger that covers up the hole or holes I can arrange so
that the amount of the stroke that is utilised can be varied by revolving the
plunger; in oil pumps for oil engines this can be used to regulate the speed of the
engine and the fact that the work of the pump is done at the time that the plunger
is travelling quickest will enable the oil to be injected in a fine spray into the
vaporizer or its equivalent.
The valve or part of the plunger that closes the hole or holes in the pump
cylinder need not be part of the plunger, it may be on a movable part or extension
of the plunger and this part only need be moved round to regulate the capacity
of the pump or the cylinder itself may be moved round or a sleeve inside the
cylinder.
1
1001
LM 1001
Improvements in Pumps for Oil Engines or other purposes.
1, WILLIAM HARDING SCOTT, Electrical Engineer, of Gothic Works King
Street Norwich in the County of Norfolk 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 :-
My invention applies to pumps the capacity of which it is desirable to vary
without altering the speed or varying the stroke.
I vary the capacity of the pumps by providing means whereby the liquid can be
returned during part of the stroke of the pump to the suction pipe or its equivalent,

page_text: and to do this I make a hole or holes in the side of the pump cylinder communicating
with the suction in such a position that at a certain part of the down stroke in a
vertical pump the pump plunger or an extension of it covers up the hole or holes;
then the communication between the suction pipe and the inside of the pump being
closed the liquid is forced through the delivery valve. Now by suitably shaping
the part of the plunger that covers the hole or holes in the side of the pump
cylinder I arrange so that by revolving the plunger through part of a revolution I
can close the hole or holes at an earlier or later part of the stroke and by having
the pump plunger hollow part way up and by cutting away part of the sides of the
hollow plunger a little higher up than the part that closes the hole or holes in the
pump cylinder I can arrange so that as the plunger goes down it opens the hole or
boles into the suction so that only the centre portion of the stroke is used and by
shaping the part of the plunger that covers up the hole or holes I can arrange
so that the amount of stroke that is utilized can be varied by revolving the
plunger; in oil pumps for oil engines this can be used to regulate the speed' of the
engine and the fact that the work of the pump is done at the time that the plunger
is travelling quickest will enable the oil to be injected in a fine spray into the
vaporiser or its equivalent.
"
The valve or part of the plunger that closes the hole or holes in the pump
cylinder need not be part of the plunger, it may be on a movable part or extension
of the plunger and this part only need be moved round to regulate the 'capacity
of the pump, or the cylinder itself may be moved round on a sleeve' inside the
cylinder.
:
4
Figures 1 & 2 of the accompanying drawings are sections at right angles to each
other shewing such parts of a pump arranged according to this invention as are
necessary to illustrate & shew what is the nature of my invention.
'
11
In these figures, A is the pump barrel the upper part of which may be provided
with a gland or any suitable arrangement for keeping the pump tight. B is the
plunger which may be driven in any suitable way. C is a rod through the plunger
connected to Diwhich is a slide valve moving with the plunger. "This rod C must
be brought out through the top of the plunger and must be tied up by means of a
screw & collar as shewn so that it must follow the reciprocating movements of the
plunger but also so that it can be twisted round a certain angle' by means of a
suitably arranged lever or its equivalent.
E Figure 2 shews the suction of the pump in section and the triangular dotted
figure marked E in Fig. 1 shews the shape of the suction entrance into the
cylinder. F. F. are the ports in the slide valve. G is the delivery from pump
and H delivery valve box.
Figure 3 is a cross section through X Y Figs. 1. & 2.
The plunger is shown in the two figures at midstroke, 'the suction entrance into
the cylinder being entirely covered up by the valve, but as the plunger is moved
either up or down the ports in the slide valve will open the communication between
the suction and the inside of the pump so that it is only for a certain time in the
centre of the pump stroke that the communication between the suction & the inside
of the pump is cut off. During this time of course the pump must deliver the
liquid in it through the delivery valve, and it is obvious that the amount of the
centre portion of the stroke that will be utilised to deliver through the delivery
valve can be varied by shifting round the slide valve on the end of the plunger so
that the suction opening into the cylinder is covered for a longer or shorter
period.
It is clear that the pump can be made to deliver at any part of its stroke by
arranging so that the suction opening is covered by the valve at that part of the
stroke, and the proportion between the maximum & minimum delivery of the pump
can be very readily varied by altering the shape of the openings in the valve &
those of the suction into the cylinder.
The slide valve on the bottom of the plunger obviously may be fixed in one with
the plunger, and the plunger itself turned round to vary the capacity of the pump.

page_text: It will also come to the same thing if the cylinder itself is turned round and not
the plunger or its valve.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
In pumps for oil engines and other purposes in which it is required to vary the
delivery without altering the number of strokes or the length of stroke providing a
slide valve which is either an extension of the plunger or is connected to it so that
it moves up & down with the plunger, and arranging ports in the slide valve and in
the pump cylinder in such a way that if they are moved round relatively to one
another the portion of the stroke during which the suction port or ports are covered
up so that the liquid has to be delivered through a delivery valve or valves is varied,
substantially as hereinbefore described.
nil
1005