Improvements in Gas Motor Engines.
Year: 1892

page_text: Date of Application, 22nd Feb., 1892
Complete Specification Left. 22nd Nov., 1892-Accepted, 31st Dec., 1892
PROVISIONAL SPECIFICATION.
Improvements in Gas Motor Engines.
HENRY THEODORE HUMPIDGE of Stroud JAMES DICKERSON HUMPIDGE of
Stroud and GEORGE EDGAR SNOXELL of Cainscross Stroud all in the County
of Gloucester trading together under the style or firm of Humpidge and Snoxell
of Dudbridge Stroud Engineers do hereby declare the nature of this invention to
be as follows:-
:-
(1.) Improved means of lubricating the main piston by means of an air tight
reservoir filled with oil. In the bottom of this reservoir is a rotating spindle with
a recess on one side communicating in one position with the oil in the reservoir, &
in another position with a chamber open to the atmosphere & leading by means of a
pipe to the cylinder to be lubricated.
(2.) An improved method of starting the engine by so arranging the valve gear
that by pulling the engine round in the reverse direction air & gas are drawn in'
during what is normally the exhausting stroke & by a continuance of the motion
are compressed & ignited causing the engine to start in the normal direction.
Dated this 20th day of February 1892.
"
H. T. HUMPIDGE.
J. D. HUMPIDGE.
G. E. SNOXELL.
COMPLETE SPECIFICATION.
Improvements in Gas Motor Engines.
HENRY THEODORE HUMPIDGE, JAMES DICKERSON HUMPIDGE and GEORGE
EDGAR SNOXELL all of Dudbridge in the County of Gloucester Engineers
trading together under the style or firm of Humpidge & Snoxell 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:-
(1.) Improved means of lubricating the main piston by means of an air tight
reservoir filled with oil. In the bottom of this reservoir is a rotary spindle with
a recess on one side communicating in one position with the oil in the reservoir
and in another position with a chamber open to the atmosphere and leading by'
means of a pipe to the cylinder to be lubricated.
(2.) An improved method of starting the engine by so arranging the valve gear
that by pulling the engine round in the reverse direction air and gas are drawn in
during what is normally the exhausting stroke, and by a continuance of the motion
are compressed and ignited causing the engine to start in the normal direction.
Our invention may be described by means of the accompanying drawings.
Fig. 1. Sheet 1. is a section of the lubricating arrangement. A is a reservoir
filled with oil through a hole in the top, which may be closed by means of the air-
tight plug B. C is a spindle working in a hole bored in the bottom of the reservoir,
having a small chamber D in its periphery. When in the position shewn in Fig. 1.
this chamber fills with oil through the passage E and the air previously contained
therein rises to the top of the reservoir. On rotating the spindle until it takes'
the position shewn in Fig. 2. the oil flows away through the pipe to lubricate the
engine as required and the air takes its place, being admitted through the small
hole F.
In any intermediate position such as shewn in Fig. 3. the oil chamber is
:

page_text: closed; and as it is impossible for any oil to escape from the reservoir until it
is replaced by a corresponding volume of air, it is evident that unless the spindle
is rotated no escape of oil can take place, whether the spindle be a perfect fit in
its hole or not. To make the supply of oil automatic the spindle C. is connected
to some part of the working mechanism of the engine, imparting to it either a
constant rotation or an oscillating motion between the positions shewn in Figs. 1
and 2, and the oil is then supplied as long as the engine is in motion at a constant
rate, whether the reservoir be full or nearly empty. When the plug B is taken
out for the purpose of filling no oil can escape, as there is no communication
between the reservoir and the outlet except by means of the chamber D.
The mechanism for starting the engine is shewn in Figs. 4 to 7 Sheet 2.
Fig. 4. is a cross section through the admission and exhaust valves with their.
operating mechanism. Fig. 5. is a longitudinal elevation of the same.
I
The admission valve A is worked by cam C, operating the lever B by means of
the roller D. The exhaust valve E is worked in the same way by means of the
cam G, the lever F and the roller H.
This roller is capable of longitudinal movement along its spindle I. enabling it to
be disengaged from its cam. In ordinary work it is kept in position by means
of the spring J Fig. 5.
The exhaust cam G is keyed on the shaft while the admission cam C runs loosely,
on it, being caused to rotate in ordinary work by means of pins L and M fixed in
the faces of the admission and exhaust cams and engaging in corresponding holes"
in the exhaust and admission cams; the cams when running being held together by
means of the spring N.
In ordinary work one complete revolution of the crankshaft serves for drawing
in a charge and compressing it, the charge exploding and exhausting on the next
revolution; the valve gear shaft making one revolution while the engine makes two.
When it is desired to start the engine it is turned round until it has nearly
completed its exhaust stroke when the exhaust valve E is almost closed. The
roller H is then slid along its pin until it disengages from the cam and the
valve seats. The roller cannot return under its cam by reason of its over-
lapping as seen in Figs. 6 and 7. The admission cam is then drawn away from
the exhaust cam until the pins are free from the holes and is then turned round
Gas is then.
from left to right until the pins come together as shewn in Fig. 6.
turned on and the engine pulled round backwards. The pin M driving the
admission cam round by means of the pin L in the direction indicated by the
arrow, thus opening the admission valve and allowing a charge to enter the cylinder..
When the piston has reached the end of its outstroke the cylinder is full of
explosive mixture. At this point the exhaust cam frees its roller which is pushed
by the spring J into its proper position for forward running. The continuation of
the backwards motion compresses the mixture, which on a point being reached a
little beyond half stroke is compressed sufficiently to be ignited, when the engine
immediately starts forwards. The impulse thus obtained is sufficient to drive the
engine round exhausting the burnt products, drawing in a fresh charge and com-
pressing it in its turn to be ignited at the proper time. The air cam turns first
with the shaft until its raised part comes against the roller, which holds it, until the
pins L and M are opposite their respective holes; when it falls into place ready
to operate the valve as required at the proper time.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. The use of an airtight oil reservoir in connection with a revolving or oscillating
plug alternately admitting air and releasing oil as described.
2. The method of so arranging the valve mechanism of a four cycle gas motor

page_text: engine that by pulling the engine round in the reverse direction air and gas are
drawn in, compressed, and ignited before the piston reaches the end of its instroke
thus driving the engine forwards as described.
H. T. HUMPIDGE.
J. D. HUMPIDGE.
G. E. SNOXELL.