Improvements in Internal Combustion Engines.
Year: 1893

page_text: Date of Application, 20th Nov., 1893
Complete Specification Left, 20th Aug., 1894-Accepted, 29th Sept., 1894
PROVISIONAL SPECIFICATION.
Improvements in Internal Combustion Engines.
JAMES ROOTS Engineer Holborn Place 261 High Holborn London do hereby
declare the nature of this invention to be as follows:-
:-
It is an improvement upon the worm gear for opening the valves such as is
described in my former Specification No. 186211, also an improvement for making
the engine reversible. In that the worm is excentric and the pinion centric, in this
arrangement the pinion is excentric and worm centric, while a quicker worm is used
such as is commonly known as screw gear. The worm wheel on the crank shaft
gears into a pinion having the usual teeth, but twice as many as those on the worm.
The pinion is fitted excentrically on a fork which is forged with or fixed on the end
of the side rod of the engine. When the crank shaft is turned the pinion in rotating
rolls or reciprocates sideways over the teeth of the worm, and its pin being excentric
reciprocates the side rod which operates the exhaust, or both valves, once for each
two revolutions of the crank shaft.
Other forms of toothed wheel can have the slower wheel fitted excentrically on
a fork on the end of the reciprocating side rod, one bearing of which rod is
preferably square. A spring keeps the wheels in gear.
To permit of the engine being started, and working equally readily in either
direction, a portion of the toothed wheel fitted on the crank shaft, which gears with
the wheel operating the side shaft, is cut away on its inner surface, so that according
to whichever direction the flywheel may be turned to start it, the toothed wheel
slips round on the shaft until stopped by the key, if not already in that position.
The stop position at each end of the segmental slot is the valve opening position.
A slot for the same purpose might be cut instead in the crank shaft. Or the same
cut-out-piece or slot to permit of slip for altering the time of the valve opening,
might be made, in other intermediate mechanism between the valve and the gearing
for opening once in two revolutions.
Dated November 20th 1893
COMPLETE SPECIFICATION.
Improvements in Internal Combustion Engines.
I JAMES ROOTS Engineer Manor Road Teddington late of Holborn Place
261 High Holborn London 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 :-
It is an improvement upon the worm gear for opening the valves such as is
described in my former Specification 18621", and also an improvement for making
the engine reversible. In the said Specification the worm is excentric and the
pinion centric, in this invention the pinion is excentric and the worm or other toothed
wheel on the crank shaft is centric, while a worm is preferably used such as is
commonly known as screw or skew gear. The worm, or slower wheel fitted on the
crank shaft has gearing into it a wheel cr pinion having twice as many teeth as
those on the crank shaft gear wheel. The pinion is fitted excentrically on a pin,
through a fork which is forged with or fixed on the side rod of the engine. When
the crank shaft is turned the pinion in rotating rolls or reciprocates sideways over

page_text: the teeth of the worm, and its pin being excentric reciprocates the side rod which
operates the exhaust, or by the aid of a cam both valves once for each two
revolutions of the crank shaft.
In a modification the usual kind of toothed wheel can have the slower or larger
wheel fitted excentrically on a fork or on a lever in a similar way, one bearing of
which reciprocating side rod is preferably square. A spring keeps the wheels in
gear.
To permit of the engine, being started and working equally readily in either
direction a portion of one of the toothed wheels is cut away on its inner or bearing
surface so that in whichever direction the flywheel may be turned to start
the engine, the toothed wheel slips round on the shaft or pin until stopped by
the key. The stop position at each end of the segmental slot is the valve opening
position. A slot for the same purpose might be cut instead with a set screw fitted.
Or the same cut out piece to permit of slip for opening the time of the valve might
be made in intermediate mechanism between the valve and the gearing for operating
it once in two revolutions.
In Figs. 1, 2, and 3, A is the worm of the screw gear fitted on the shaft B, and
gearing into the pinion C, which is fitted on the pin D, and rotates at half the speed
of the worm A. In Fig. 1, E E are the bearings of the reciprocating side shaft F.
The spring G keeps the wheels in gear. Z is the valve spindle opened by the
reciprocation of the rod F. In Figs. 2 and 3 the pin D forms part of the lever F 1,
the excentricity of which in the pinion C when the wheel rotates oscillates the
lever F 1 on the fulcrum E1 and opens the exhaust valve Z. The cam His
screwed or otherwise fixed on the pinion C and in rotating with it operates the
lever F 2 by means of the roller H 1 and opens the admission valve Y. In Fig. 1
a portion of the inner wearing surface of the worm is cut away to permit the
worm A the necessary free movement on the shaft to open the valve every other
revolution at the right time when the engine is going in the other direction. J is
the piece cut away, and when the key is at one end position it is so adjusted that it
opens the valve in going one way, and the other end of the space is the position for
the opposite direction of rotation. Fig. 4 shows the slot or space cut in one of the
pair of ordinary toothed gear wheels. Fig. 5 shows the slot cut in a rotating cam
shaft F 3, the stop being a set screw instead of a key.
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
cluim is.
1. In internal combustion engine gear wheels, used for the purpose of opening
the valve, making the slower or half speed one of the two wheels excentric upon its
pin, and the pin movable, so that it reciprocates a shaft or rocks a lever to operate
the valve or valves, substantially as described and shown.
2. In internal combustion engines upon the four-stroke cycle cutting out a
segmental portion of a toothed wheel, cam, or other part, which transmits the motion
of the crank shaft to the valve, to enable the engine to run in either direction, as
described.
3. The combination of gear wheels in internal combustion engines and a valve
or valves, together with intermediate mechanism for conveying the motion of the
one to the other, having in some part or parts a segmental portion or slot cut away
to permit of the engine running in either direction.
4. The combination of gear wheels and cam or cams such as described and shown
in Figs. 2 and 3.