IMPROVEMENTS IN DIFFERENTIAL VALVE GEAR FOR PUMPING AND OTHER ENGINES"
Year: 1883

page_text: LETTERS PATENT to Henry Lawrence and Robert Mather Ogle, both of
Durham, in the County of Durhamn for an Invention of "IMPROVEMENTS IN
DIFFERENTIAL VALVE GEAR FOR PUMPING AND OTHER ENGINES"
PROVISIONAL SPECIFICATION left by the said Henry Lawrence and Robert
Mather Ogle at the Office of the Commissioners of Patents on the 5th July
1883.
HENRY LAWRENCE and ROBERT MATHER OGLE, both of Durham, in the County
of Durham IMPROVEMENTS IN DIFFERENTIAL VALVE GEAR FOR PUMPING AND
OTHER ENGINES"
Our invention relates to direct acting Engines operated by steam or other
elastic or non-elastic fluid, in which the piston rod is connected directly to a pump
rod or other machinery which is to be driven, without the intervention of driving
shaft, crank, or fly wheel. It has for its object a novel method of actuating the
slide or other valve of the steam cylinder, in such manner that such valve is only
set in motion automatically backward and forward at a speed corresponding with
that at which it is desired that the Engine is to work, whilst it is impossible that
the piston can strike the ends of the cylinder in which it works, and to cause
injury.
We connect the outer end of a link, which actuates the slide valve spindle in
the usual way, to the outer end of a lever the inner end of which turns upon a
shaft or spindle suitably arranged. We form the lever so that at a convenient part
of its length a bevilled toothed wheel can be fitted so as to revolve freely, at right
angles to the lever but parallel to the shaft. Upon the shaft we fit so as to revolve
freely two corresponding bevilled toothed wheels one upon each side of the lever,
with the wheel upon which they are in gear, and upon one of the two bevilled
toothed wheels last described we arrange a lever connected by one or more rods to
the piston rod or other moving part of such Engine, whilst the other such wheel
is connected in a similar way to the plunger of an adjustable cataract of any
the ordinary well known kinds, the speed of which can be regulated as desired
within any required limits.
of

page_text: When therefore the Engine and the cataract plunger are moving at the same
speed (or at such constantly proportioned relative speed as may have been
arranged) one of the toothed wheels upon the shaft is driven in one direction and
the other in the opposite direction at the same speed, and the intermediate wheel
upon the lever revolves upon the latter but without causing the lever itself to
move round upon the shaft.
When however, the relative velocities of the two wheels vary, the centre wheel
and the lever are made to move round in one or the other direction and the position
of the valve spindle and valve is altered accordingly.
Apparatus constructed according to our invention is simple, cheap, durable, and
easy to apply and use.
•
It may be varied more or less in its details to suit the varying circumstances
and conditions in which it is to be used, as for instance the lever described which
carries the bevilled toothed wheel may be extended on the opposite side of the
shaft or spindle, and there connected to the link which actuates the valve. Or, a
bevilled toothed wheel may be arranged upon each side of the shaft or spindle.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Henry Lawrence and Robert Mather Ogle in the Patent Office on
the 5th.January 1884.
:
HENRY LAWRENCE, and ROBERT MATHER OGLE both of Durham in the County
of Durham 'IMPROVEMENTS IN DIFFERENTIAL VALVE GEAR FOR PUMPING AND
OTHER ENGINES
"
Our invention relates to direct acting Engines operated by steam or other elastic
or non-elastic fluid in which the piston rod is connected directly to a pump rod
or other machinery which is to be driven without the intervention of driving shaft,
crank or fly wheel.
It has for its object a novel method of actuating the slide or other valve of the
steam cylinder in such manner that such valve is only set in motion automatically
backward and forward at a speed corresponding with that at which it is desired
that the Engine is to work, whilst it is impossible that the piston can strike the
ends of the cylinder in which it works, and so cause injury.
The accompanying drawing is in illustration of our invention, and shews our
novel apparatus applied to a direct acting pumping Engine. Figure 1 is a sido
view shewing the apparatus, figure 2 an end view partly in section, and figure 3
a plan. The same letters of reference indicate similar parts in the several figures.
We connect the outer end of a link a which actuates the slide valve spindle b
in the usual way to the outer end of a lever c the inner end of which turns upon
a shaft or spindle & suitably arranged. We form the lever c so that at a convenient
part of its length a bevilled toothed wheel e can be fitted so as to revolve freely,
at right angles to the lever c but parallel to the shaft d. Upon the shaft & we
fit so as to revolve freely two corresponding bevilled toothed wheels f, g, one upon
each side of the lever c with the wheel e upon which they are in gear, and upon f
one of the two bevilled toothed wheels last described we arrange a lever
connected by one or more rods i to the piston rod or crosshead k or other moving
part of the Engine, whilst the other such wheel g is connected in a similar way
by a lever or rod to the plunger of an adjustable cataract of any of the ordinary
well known kinds, which may be worked by hydraulic pressure from the main or
by an auxiliary steam cylinder or in other convenient manner, and the speed of
which can be regulated as desired within any required limits. By admitting steam
or other fluid therefore, under pressure into the auxiliary cylinder motion is com-
municated through the rod and lever to the bevilled toothed wheel g and thence
to the corresponding bevilled toothed wheel e. The wheel ƒ in the meantime
remains stationary and acts as a resisting fulcrum so that the lever c upon which
the wheel e is fitted revolves round the shaft d and opens the main valve of the
Engine by the rod a.
-
As soon as the main valve of the Engine has thus opened sufficiently to start
the Engine, the wheel of commences to revolve by means of the lever h and the
rods in an opposite direction to the wheel g, and in its movement it actuates
the wheel e and lever c in the opposite direction so as to close the Engine valve
sooner or later according to the resistance and the speed at which the Engine
piston travels relatively to that of the auxiliary piston or plunger driving the
rods and wheel g. This relative speed of the wheel g is determined and adjusted
as desired in the ordinary well known way by an auxiliary regulating cataract
cylinder and valves.
When therefore the Engine and the cataract plunger are moving at the same
speed (or at such constantly proportioned relative speed as may have been
arranged) one of the toothed wheels f, g, upon the shaft is driven in one direction

page_text: and the other in the opposite direction at the same speed, and the intermédiate
wheel e upon the lever c revolves upon the latter but without causing the lever
itself to move round upon the shaft.
When however the relative velocities of the two wheels f, g, vary, the centre
wheel e and the lever c are made to move round in one or the other direction and
the position of the valve spindle and valve is altered accordingly.
The valve of the auxiliary cylinder which drives the wheel g as described is
reversed at the proper time by means of adjustable tappets and rod n, worked by
the lever h and actuating the auxiliary cylinder, valve spindle o, by, means of the
weighbar m, and the same movements then take place in the opposite direction,
the main valve spindle b being driven in the opposite direction so as to accomplish
the return stroke of the Engine, and so on as long as may be desired. A handle
and disconnecting gear are shewn by which the valve spindle o can be operated by
hand when required for the purpose of starting the Engine.
Apparatus constructed according to our invention inay be varied more or less
in its details to suit varying circuinstances and the kind of Engine to which it is
applied. In figure 4 two bevilled wheels e are shewn, loose upon the lever c,
opposite to each other and both gearing with the wheels fand g, and in this way
greater strength is obtained. In figure 5 the wheel e is shewn upon the same end
of the lever as the link a, instead of upon a prolongation of it at the opposite side
of the centre as shewn in figures 1, 2, and 3. Apparatus constructed according to
our invention is simple, cheap, durable, and easy to apply and use.
We do not confine ourselves to the precise arrangement and proportions of
the apparatus described and shewn, which may be modified to suit varying
circumstances, but having now described our invention and the manner in, which
it is to be performed, we claim :-The combination of the three or more bevilled
toothed wheels geared together and revolving freely upon the cross-shaft and
rocking lever, all actuated and operating the valves of steam or other Engines
substantially in the manner and for the purpose described and shewn in the
drawing.
In witness whereof we the said Henry Lawrence and Robert Mather Ogle
have hereunto set our bands and seals this 5th day of January in the Year of
Our Lord 1884.
+
HENRY LAWRENCE
(L.S.)
ROBERT MATHER OGLE (L.S.)