Improvements in Gas, Vapour, and Oil Engines.
Year: 1898

page_text: Date of Application, 22nd Feb., 1898
Complete Specification Left, 22nd Nov., 1898-Accepted, 7th Jan., 1899
PROVISIONAL SPECIFICATION.
Improvements in Gas, Vapour, and Oil Engines.
HENRY CAPEL LOFFT HOLDEN, Major Royal Artillery, Royal Arsenal, Woolwich,
Kent, do hereby declare the nature of this invention to be as follows: -
My invention relates to improvements in gas vapour and oil engines and
has reference especially to the form described in my Patent No. 11491 of 1896,
and the object of my said invention is to enable the power of the engine to be
varied, either whilst running or at rest, by lengthening or shortening the stroke
of the pistons, the length of the crank and the stroke of the connecting rods
remaining the same.
In this manner the amount of explosive charge drawn into the cylinders at
each stroke can be varied from a maximum to nil and the power of the engine
varied accordingly, its speed remaining the same or not according to the condi-
tions. In order to effect this I attach the ends of my connecting rod or rods
to a short bar or bars, the bar or bars being pivotted at one end to the connecting
rod or rods and at the other on studs or pins whose position can be altered on
an arc, preferably struck with a radius equal to the length of the connecting rod.
The crosshead bar of the piston or pistons slides in a groove in or is similarly
attached to the above mentioned arc and in such a manner that by shifting
the are the crosshead bar may be made to coincide with the pivot of the connecting
rod or rods, in which position the piston will have a maximum stroke or may
be coincident with the centre of the stud or pin on which the short bar pivots
in which position the stroke will be nil.
In any intermediate position between these extremes the stroke of the pistons
will be greater or less according to the relative distances between the centres
of the fixed pin, the crosshead bar, and the connecting rod.
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H. C. L. HOLDEN,
Major, R.A.
Improvements in Gas, Vapour, and Oil Engines.
HENRY CAPEL LOFFT HOLDEN, Major Royal Artillery, Royal Arsenal, Woolwich,
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 relates to improvements in gas, vapour, and oil engines and

page_text: has reference especially to the form of engine described in my Patent 11491 of
1896, though I do not confine its application to this type or to any other type of
engine; furthermore the object of my invention is to enable the power of the
engine to be varied, either whilst running or at rest, by lengthening to a maxi-
mum or shortening to a minimum the stroke of the piston or pistons, the throw
of the crank and the stroke of the connecting rod or rods meantime remaining
the same.
In this manner the amount of the explosive charge drawn into the cylinders
at each stroke can be varied from the maximum to nil and the power of the engine
varied accordingly, its speed remaining the same or not according to the condi-
tions under which it is working. In order to effect this I attach the ends of my
connecting rod or rods to a short bar or bars, this bar or bars being pivotted
at one end to the connecting rod or rods and at the other end on studs or pins
whose position can be altered on an arc, preferably an arc struck with a radius
equal to the length of the connecting rod. The other end of the connecting rod
The crosshead bar
or rods is attached to the crank pin in the usual manner.
of the piston rod or rods slides in a groove or is attached in a similar manner
to the above mentioned are, in such a manner that by shifting the arc, the
crosshead bar may be made to coincide with the pivot of the connecting rod or
rods, in which position the piston will have a maximum stroke, or may be made
to coincide with the centre of the stud or pin on which the short bar pivots, in
which position the stroke of the piston will be nil.
In any intermediate position between these extremes the stroke of the piston
will be greater or less according to the relative distances between the centres of
the fixed pin on the are the crosshead bar, and the connecting rod.
Referring now to the accompanying drawing in order to more clearly explain
my invention and the manner in which it may be carried into effect.
Fig. 1 shows a side elevation of one form of my invention. Fig. 2 shows a
section and elevation of the same on the line X Y. G G show the cylinders
of the engine to which my invention is applied in the drawing; the engine
being that described in my Patent of 11491 %. I do not however confine the
application of my present invention to this form or indeed to any particular form
of engine.
A A are the connecting rods connected to the crank pins on the cranks H
of the fly wheel shaft, the other ends of these connecting rods A A are pivotted
on studs or pins CC fixed on the end of short bars B B which themselves are
pivotted at their other ends on studs or pins D D attached to the radius bars I I;
these radius bars being moveable about the centre of the main shaft, some device
such as that shown viz.: a handwheel and screw L, a nut M and support K
attached to some fixed part of the engine, being employed, to allow of the position
of the radius bar being adjusted; the support K and the nut M being pivotted
or similarly arranged so as to adjust themselves to whatever relative positions
may be required. Instead of the radius bars, a slot cut in a fixed bar, links or
an equivalent device may be employed to effect the same purpose. The bars BB
have grooves F F in them from end to end on the sides next to the cylinders G G,
these grooves F F being shown in the drawing, by dotted lines, and in these
grooves FF the ends of the crosshead EE engage, the crosshead being connected
to the pistons.
In the position shown the centre of the pin C fixed to the bar 13 coincides with
the centre of the crosshead E, which as has already been stated engages in the
groove F in B. This position therefore corresponds to the maximum stroke of
the piston. If however the radius bar I be moved down by means of the screw L
and nut M into such a position that the centre of the pin or stud D coincides
with the centre of the crosshead E, then the stroke of the piston rod will be
nil, and in intermediate positions between the extremes described the movement
of the piston will be more or less according as the distance between the centres
of D and E is more or less.

page_text: Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. The method of varying the power of gas vapour and oil engines by increasing
or decreasing the stroke of the piston or pistons of the same whilst the engine is
running or when it is at rest.
2. The arrangement and combination of parts substantially as described and
for the purposes set forth.
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