IMPROVEMENTS IN GAS-MOTOR ENGINES
Year: 1888

page_text: We GEORGE MCGHEE and PETER BURT, both of the "Acme Machine" Works,
Henrietta Street, Glasgow, in the County of Lanark, Scotland, Engineers, do hereby
declare the nature of our invention for IMPROVEMENTS IN GAS-MOTOR ENGINES to be
as follows:
This Invention relates to improvements in Gas-motor Engines, and comprises
mechanism for Governing such, and improved arrangements and combinations of
Engines and Gearing for causing the two pistons of the Gas Engines described in the
Specification of George McGhee's British Patent No. 14578 dated 11th Novr. 1886 to
work in unison together.
The Governing mechanism under one modification of the Invention comprises a
hook or cam fitted on a shaft revolving in proportion to the cycle of operations of the
Engine as will be well understood by Engineers conversant with such Engines. The
said hook, when Engine is working at desired speed, comes against a pin or stud fixed
on a part of the supply valve rod and epens the valve. The said part of the rod is
actuated by a cam against, and put into proper position by means of, an adjustable
spring, which takes a given time to effect said action, so that if the Engine exceeds
desired speed the hook shall come opposite the pin before said pin is in proper position
to be actuated thereby; thus the hook revolves past the pin without actuating it,
consequently allowing the valve to remain shut that revolution of hook.
Under another modification, the Governing Mechanism comprises two cams fitted
on a shaft as before set forth, one cam being for pushing a roller or catch fitted on a
stud capable of transverse motion against an adjustable spring on the valve rod, the
other cam being for actuating said roller and consequently valve rod. At the desired
speed of Engine the spring adjusts the roller into proper position just in time to be
actuated by the 2nd cam; but should Enginc exceed desired speed the 2nd cam shall
have revolved past the edge of roller before the spring shall have put it into proper
position, so that the rod is not actuated that revolution of 2nd cam, and supply valve
consequently remains shut.

page_text: The arrangement of Engine has the two cylinders lying alongside each other, the Fly-
wheel shaft being before the other crank-shaft; the connecting rods being of different
lengths to suit position of shafts which are geared 2 to 1 together.
The Gearing mechanism comprises a toothed wheel fixed on one end of a connecting
rod fitting on a pin in a crank revolving on main crank-shaft, to which shaft is also fixed
another toothed wheel driving or driven by first wheel.
We GEORGE MºGHEE and PETER BURT, both of the Acme Machine Works,
Henrietta Street, Glasgow, in the County of Lanark, Scotland, Engineers, 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 :-
Our said Invention relates to improvements in Gas motor Engines and comprises
Mechanism for governing such Engines, and improved_modifications of the Gas
Engines described in the Specification of the British Patent granted to George
McGhee No. 14578 dated Nov. 11th 1886 to which said Specification reference is
here had.
On the accompanying sheet of Drawings Figures 1 and 2 are respectively an
elevation and plan, and Fig. 3 a modified transverse view of the Governor as con-
structed according to our present Invention and figs. 4 and 5 plans illustrating
improved horizontal types of McGhee's No. 14578% Patent Gas Engines as arranged
and modified according to this Invention.
The Governing Mechanism is fitted on and actuated through a shaft revolving in
proportion to the cycle of operations of the Engine, so as when Engine is working at
normal speed, to open the gas inlet valve every cycle, but when such speed is exceeded
to allow said gas valve to remain shut.
The Governor comprises, as shown at Figs. 1 and 2 a thin steel cam ? and wide
cams formed on a ring fixed on Engine shaft fat z. The cam s is inclined backwards
on face from s¹ to s as shown at Fig. 2 so as when revolving (as indicated by arrows)
to push the sliding stud t fitted in collar formed on valve rod u transversely outwards

page_text: | against the spring » which spring presses stud & transversely back again when cam s
has revolved past stud t. When Engine is working at normal speed the cam > now
comes against stud and pushes it and also thereby valve rod u, (which rod has end
forked and capable of sliding on shaft z) along with it, thereby opening the gas supply
valve. The rod u is pressed back again by a spring w Figs. 4 and when cam s.
has passed stud thereby shutting valve. The speed of Engine and thereby of
revolution of cam r being variable while the action of spring is constant the stud t
would sometimes not be driven in far enough in time by spring to give a good
bearing for cam to drive rod u forward, and thereby the stud would be apt to be
much worn at end, and slip transversely off said cam . To obviate this the stud t
has fixed thereon a bevel eilged round steel disc against which sometimes comes the
correspondingly inverted bevel edge of a thin cam fixed on and revolving with
shaft z.
The cam y in revolving comes opposite the disc before the cam r comes
opposite stud t. When shaft z is revolving at or under normal speed the cam y locks
or passes on the outside of disc and keeps it and thereby also stud t inwards while
cam drives said stud and thereby also rod u forwards thus opening the gas valve.
If Engine exceeds normal speed (the action of the spring to press back stud t being
constant at all speeds according as said spring is set by pinching screw and handle v¹)
the cam y revolves faster and locks on inside of disc before disc has had time to be
pressed back, and keeps it and thereby stud t back until cam has revolved past said
stud, so that the rod u is thus not actuated and gas valve consequently remains shut
that cycle.
Under a modification of foregoing the cam may be dispensed with by making the
cam y furrowed or V shaped on edge and placing it further in in position as indicated
by dotted lines y fig. 2. so that it shall fit on to the disc e and drive it and also rod u
forward, thus opening the gas supply valve when revolving at normal speed. Should
engine and consequently cam y exceed normal speed the spring v will not have had
time to put disc (after being pressed out by cam s) opposite said- cam y' when it
revolves quicker round; therefor said cam y revolves inside and past disc z
thereby not driving it forward and also not actuating rod u and opening gas valve
that cycle.
In lieu of using the spring » for pressing back the stud t after being pressed out by
cam s, said spring may be dispensed with and weights used instead, as shown at Fig. 3
which is a transverse section on the rod u Fig. 1 looking to the left. The rod u has
thus fixed thereon a depending arm u' on which is fulcrumed the bent lever o on or to
one end of which are placed weights o¹. The other end of said lever bears against and
presses the spindle inwards, with a force proportionate to the weights o' which
may be varied.
One of our present improvements on the Gas Engines described in the specification
of the aforesaid Patent No. 1457888 granted to George McGhee, consists merely in
the modified arrangement of the essential parts thereof as illustrated in plan by Fig. 4,
wherein the 2 cylinders a, b lie alongside each other. The flywheel shaft g is placed
before the other crank shaft f, both shafts g. f. being fitted in bearings d. and
revolving oppositely as indicated by arrows. The cranks g' f¹ are respectively
connected to rods a ₁ of different lengths, (the rod a' being longest) to suit positions
of shafts fg which are geared together as originally by the toothed wheels hi
Under another modification, as shown in plan at Fig. 5, the Engine has the two
crank shafts f. g. lying in the same line and revolving in same direction and connected
together by means of a set of mechanism known as Watt's Sun and Planet motion
which comprises the toothed wheel h fixed on end of connecting rod a¹ fitting on the
pin fin crank f the outer journal of which fits in bearing f and the inner journal ƒ³
(shown black in section)" is formed hollow and revolves on main shaft 9. The
shaft y las fixed on inner end the pinion i same size as wheel into which it gears
and thereby causes the crank f to revolve at half the rate of crank g' which thereby
gives the proper relative motions to the two pistons e. d.
Both the foregoing modifications of Engine are represented as being fitted with the
Governor hereinbefore described but otherwise the Engines are in all respects similar

page_text: to and operate in the same manner as those described in the Specification No. 1457886
before referred to.
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.
1st. The arrangement, construction and combination of the parts constituting the
Gas Engine Governor substantially as herein before described and shown.
2nd. The improved arrangement of Gas Engine as set forth and shown with
reference to Fig. 4.
3rd. The combination of the Sun and Planet Motion in the Gas Engines referred
to as and for the purpose set forth and shown at fig. 5.
Dated this Fifth day of December 1888