Year: 1899

page_text: Date of Application, 8th July, 1899
Complete Specification Left, Sth Apr., 1900-Accepted, 23rd June, 1900
I, MICHAEL HOLROYD SMITH, of Albany Buildings, 47, Victoria Street, West-
minster, Consulting Engineer, do hereby declare the nature of this invention
to be as follows:-
The object of this invention is improvements in the construction of oil or petrol
engines with a special view to their use on motor cars, though the same engines
will be applicable to numerous other purposes.
The engine may be described as a diagonal engine, namely two cylinders are
preferably placed at an angle of 90° to each other. One can be vertical and one
horizontal or each can be at an angle of 45° to the vertical or horizontal plane etc.
The operation of each piston is what is commonly known as the Otto cycle,
and the valves of the engine are preferably so set that the impulses occur at
&1 of the two revolutions of the crank that go to make the Otto cycle.
The cylinders rest upon an enclosed base forming the crank chamber, which
may be conveniently described as a drum, one side being preferably cast with the
chamber and carrying one of the bearings of the crank shaft, the other bearing
of the crank shaft being carried in a fixing with a base resting upon & fastened
to the inner surface of the drum. The fixing can be slided in and out of position
wlien required, and also carries the bearings for the cams & wheels that operate
the valves.
I preferably employ distinct wheels & cams, one for cach cylinder. On the
end of one cam shaft is placed a crank pin or its equivalent to operate an air
pump supplying air to the pneumatic governors that control the engine.
Either or both of the cam. shafts can be continued through suitable stulling
boxes in the removable cover or lid which closes the other side of the drum. One
or both of these may be used to carry an electric ignition device, or to operate a
water circulating pump for other purposes. The crank shaft can also be carried
through the drum cover, and used as the means of conveying the power, or for
starting the engine with the usual handle or sweep, or for driving a centrifugal
pump when one is employed or for other purposes.
The drum end or cover can at any time be removed for examination of the cams.
wheels & other mechanism within the crank chamber.
The spindles of the exhaust valves are operated by a cam acting upon a pulley
or roller the base of the spindles are preferably tubular and are prevented from
turning by a slot working on a cross key held in the guide bush."
The spindles are provided with concentric devices for adjusting the tension of
the springs, a locking arrangement and suitable collar to engage with the lever
or detent of a pneumatic governor forming part of the structure of the guide
bush of the valve spindle.
The pneumatic governors are adjustable as to tension of the resisting spring
and are preferably coupled in series with the pressure pump.
The pressure pump is provided with suitable inlet and outlet valves and a

page_text: safety valve and the pipe from the pneumatic governors with suitable adjust-
ments to control the speed:
A hand hole is provided at the top of the crank chamber preferably between
the two cylinders and another hand hole is at the base.
Each cylinder is preferably cast with a water jacket the exhaust and admission
valve boxes are cast separately and bolted to the cylinder.
In addition to the usual inlet and outlet passages the cylinders are provided
with three small entrances to the combustion chambers, one for a tube ignition
one for electric ignition, and one for a snift valve to relieve the compression
pressure when starting the engine.
Facings are provided on the water jacket for the entrance and exit of the cir-
culating water.
The pistons are compound that is to say they consist of a piston within a piston,
the outer one being the piston proper provided with packing rings. The inner
one screwing into the outer one carries the pin of the connecting rod. By this
device the following results are secured, shorter length of cylinder more packing
rings, facility for adjustment of compression, because the outer piston which is
screwed onto the inner one can be raised or lowered as required.
In a two cylinder engine the two connecting rods work onto the same crank
pin, one overlapping the other, and are provided with hinged caps and a special
spring catch device for adjusting and locking the same.
It is obvious that the structure of engines in accordance with this invention
need not be confined to two cylinders and that most of the details are applicable
generally to impulse engines.
1, MICHAEL HOLROYD SMITH, of Albany Buildings, 47, Victoria Street, West-
minster, Consulting 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:-
The object of the invention is improvements in the construction of oil or petrol
engines with a special view to their use on motor cars, though the same engines
will be applicable to numerous other purposes.
The engine may be described as a diagonal engine, namely two cylinders are
placed at an angle of 90° to each other, one can be vertical and one horizontal! or
each can be at an angle of 45° to the vertical or horizontal plane etc..
The operation of each piston is what is commonly known as the Otto cycle, and
the valves of the engine are preferably so set that the impulses occur at. and 1
of the two revolutions of the crank that are required to make the Otto cycle.
In order that this invention may be more easily understood, reference is made
to the accompanying drawings in which like letters or figures refer to like parts.
Figs. 1, 2, 3, 4 (Sheet 1) show the general arrangement of the engine, giving
side elevation, end elevation, plan, and section, respectively.
Figs. 5, 6, and 7. (Sheet 2) show the construction of the piston and connecting
rods.
Figs. 8, 9, and 10 (Sheet 3) show the details of the exhaust valve, valve action
and governing device.

page_text: The cylinders A, A, rest upon an enclosed base B3 forming the crank chamber
which may conveniently be described as a drum, one side C being preferably cast
with the chamber and carrying one of the bearings I) of the crank shaft P. E is
the other bearing of the crank shaft carried by the fixing I with a base so formed
& turned as to rest on and be fastened by bolts, set screws or the like to the inner
surface of the drum B. The fixing can be slided in or out of position, when
required, and also carries the two bearings 1, 2, for the cams 3, and wheels 4 that
operate the exhaust valves.
I preferably employ separate wheels and cams, as shown, one for each cylinder,
both operated by the pinion G on the crank shaft P. On the end of one cam
shaft 1, is placed a crank pin 5 or its equivalent to operate an air pump 6
supplying air to the pneumatic drums 7 that control the speed of the engine
in the manner herein after described.
Either or both of the cam shafts can be continued through suitable stuffing
boxes 8 in the removable cover or lid, 9, which closes the other, or open,
side of the crank chamber drum B. One or both of these may be used to carry
an electric ignition device 10, or to operate a pump for circulating water, or
for other purposes. The crank shaft P can also be carried through the drum
cover and used as the means of conveying the power (when not taken from the
fly wheel end of the crank shaft) or for starting the engine (with the usual
handle, or sweep) or for driving a centrifugal pump when one is employed; or
for other purposes.
The drum end or cover, 9, can at any time be removed to permit ready
examination of the cams, and wheels, and other mechanism within the crank
chamber B.
A hand-hole K is provided at the top of the crank chamber, preferably
between the two cylinders, and another hand hole I is placed at the base, to be
used for removing waste oil, and dirt, and to facilitate examination of the
cranks and other parts.
Each cylinder is preferably cast with a water jacket. The exhaust valve
boxes and admission valve boxes J, are cast separately and bolted to the
cylinder.
In addition to the usual inlet and outlet passages, the cylinders are pro-
vided with three small entrances to the combustion chamber. One, 11, for
a tube ignition, one, 12, for electric ignition, and one, 13, for a snift valve .to
relieve compression pressure when starting the engine.
Facing are provided on the water jackets, 14, for the entrance of the circulating
water and 15 for the exit of the circulating water.
The pistons are compound, that is to say, they consist of a piston within a
piston (see Sheet 2) the outer one, 16, being the piston proper provided with
packing rings, 17.
The inner piston, 18, screwing into the outer piston, 16, carries the hollow pin 19
of the connecting rod 20. By this device the following results are secured,
shorter length of piston and cylinder, more packing rings, facility for adjusting
the capacity of the compression space because the outer piston which is screwed
into the inner one can he raised or lowered as required.
For preventing the outer piston from turning inadvertantly, it is locked in
the desired position by the key z, having a spring extension y, provided with a
pin engaging with the hole i. When the key is withdrawn the outer piston
can be turned a half, or whole revolution, and the key again inserted, retaining
it in position. The pin, engaging with the hole ; prevents the key from shaking
out.
In this two cylinder engine the two connecting rods 20, 21, work on the same
crank pin 23, one overlapping the other as shown in Fig. 6, and they are each
provided with caps.
The caps 24 are hinged to their respective connecting rods by the pins 25 and
carry at their other ends a bolt 26, also hinged to them at 27. This bolt is, when

page_text: loose, free to swing in or out of the fork shaped projection 28, on the end of the
connecting rod, and the bolt has attached to it the spring 29, that will enter with
the bolt between the forked projection 28 and engage with the serrated or notched
edge of the washer or shoulder forming part of the nut 30, and so prevent it from
turning. This nut is operated by a box spanner, which when applied to the nut
forces out the spring catch 29 releasing the notched collar and permitting the
nut to be turned.
When the box spanner is removed, the spring catch returns and engages
with the notches in the collar, thus automatically locking the nut.
The spindles of the exhaust valves are each operated as follows. A cam 3
(see Fig. 8 Sheet 3) acts upon a pulley or roller 31.
The base 32 of the valve spindle is preferably tubular, and is prevented from
turning by a slot working on a cross-key 33 held in the guide bush 34. Into the
base 32 is screwed or otherwise secured the portion 35 bored and tapped for the
reception of the valve spindle 36, the length of which can be adjusted by screwing
it in or out of the portion 35.
For locking the spindle in position, the portion 35 is split, as shown at 27,
and the end is cone-shaped, the base of the lock-nut 38 is also hollowed cone
shape and by screwing it down it nips. the portion 35 and causes it to grip the
valve spindle 36 thus locking it tight.
Between the dishes 39, 40 the spring 41, is placed, the tension of which can
be adjusted by turning the dish 39 on the extended screwed portion of the
bush 42, through which the valve spindle works.
Figs. 8, and 9, show the construction of the exhaust valve box. It will be
seen that the valve and spindle can be readily withdrawn through the circular
hole 43. This hole is closed by the cup 44, making a ground joint. The cup
is held in position by the set screw-45, which passes through the cap 46. This cap
is provided with wings 47 that engage with what may be conveniently described
as the bayonet grooves 48 formed on the surface of the valve box. When the
set screw 45 is slackened and the cap 46, is given a half turn, it can be at once.
removed, permitting access to the valve box and spindle.
The engine can be controlled by varying the strength of the mixture for the.
explosive charge, or by adjusting the time of ignition, when electric ignition
is employed; both these methods are in use on other engines. Centrifugal or
other inertia governors could be used, but I preferably employ pneumatic governors
in the following manner.
The crank pin 5, on the cam shaft, works, through a suitable connecting rod,
a plunger in the air pump, 6, provided with suitable inlet and outlet valves;
also a relief valve to prevent the pressure from becoming excessive: From the
air pump 0, a pipe 49 leads to the drum 7-conveying air thereto, which is free
to pass out by the union on the opposite side whereby it is connected by a pipe
with the second drum, 7; the outlet from the second drum being connected to a
pipe 50 leading to a position conveniently within reach of the driver (when
the motor is used for propelling a car) the end of the pipe being provided with
a screw cap acting as a throttling device. Each drum is provided with a dia-
phragm 51 (Fig. 8) protected by a stamped or spun dish 52. The diaphragm and dish
are by an adjustable screw link 53 attached to the tilting lever 54 which is
restrained by the spring 55. When the cap on the end of the outlet pipe -50 is
throttled the pump, still working, increases the pressure within the drums and
overcoming the tension of the springs forces forwards the tilting lever 54, causing
it to engage with the collar 56, on the nut 38; thus preventing the valve
spindle 36 from falling after it has been raised by the cam 3, and thereby keeping
The exhaust valve open, and as a result no explosive charge will be drawn into
the engine through the air inlet or induction valve J.
By regulating the tension of the springs and the throttle at the end of the
air pipe 50 the speed of the engine can be varied, by entirely closing the outlet
of the air pipe 50 the engine can be stopped.

page_text: It is obvious that the construction of engines in accordance with this invention
need not be confined to two cylinders and many of the special details shown
and described are applicable to impulse, (viz. oil or gas), engines generally.
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. Oil or gas engines constructed substantially as and for the purpose illus-
trated and described.
2. The combination in gas or oil engines of two cylinders placed diagonally
one with the other (their axes being in the same vertical plane) with the drum
shaped crank chamber, the connecting rods acting upon one crank pin and the
removable fixing carrying the gear wheels substantially as and for the purpose
illustrated and described.
3. In gas or oil engines the combination of the cylinder and separate, exhaust
valve box with bayonet cap and the separate admission valve box substantially
us and for the purpose illustrated and described.
4. In gas or oil engines compound pistons constructed substantially as shown
in Fig. 8 and for the purpose described.,
5. The construction of connecting rods having a hinged cap 24 (Fig. 5) a
rocking bolt 26, spring 29 and nut with serrated base 30 substantially as and
for the purpose illustrated and described.
6. In gas or oil engines the combination with the drum shaped crank chamber
of the removable fixing such as F carrying the gear wheels and cams, substan-
tially as and for the purpose described.
7. In gas or oil engines the combination of the air pump 6 the pipes 49-50,
the drum or drums i, the tilting lever 54, with adjustable spring 55, or the
like, engaging with the collar 56 or its equivalent and an adjustable choking cap
substantially as and for the purpose illustrated and described.
8. In gas or oil engines the combination of electric ignition device, tube ignition
device, and snift plug substantially as and for the purpose described.
Da li 0411 of 1000
M. HOLROYD SMITH.