IMPROVEMENTS IN VALVE-GEAR FOR STEAM OR OTHER FLUID-PRESSURE ENGINES
Year: 1885

page_text: We, THOMAS MCCULLOCH and DAVID MCCULLOCH, both of Vulcan Foundry,
Kilmarnock Ayrshire, and THOMAS WHITE, of 5 Thomson Street, Govan, Lanark-
shire, Engineers, do hereby declare the nature of our Invention for "IMPROVEMENTS
IN VALVE-GEAR FOR STEAM OR OTHER FLUID-PRESSURE ENGINES;" to be as
follows:-
:-
This Invention has reference to an improved combination, or arrangements of
mechanism or gear for actuating the distributing valves of single or compound
cylinder, steam or other fluid-pressure motive-power engines, and specially
applicable to reciprocating or non-rotative engines, such as much used for working
pumps and air compressers direct or through bell-crank or other levers, without
intermediate rotative crank shafts. These improvements are susceptible of slight
modification to suit the construction of engine and disposition of its valves and
valve chest, and they will enable the engines fitted with them to work more highly
expansively, more economically; better, and steadier, than such engines as hereto-
fore constructed have done.
-
The nature and novelty of the Invention or improvements consist as follows:
say as applied to a single cylinder horizontal steam engine with its reciprocating
piston-rod, or its continuation as coupled to cross-head, transmitting the power
direct as stated,-In the application of a special crank shaft, light but strong
enough for effectively actuating the main and cut-off slide or other valves of the
large engine, by eccentrics or cranks and their connecting rods or links. This
shaft, for working the valves of the main engine is driven in the proper direction
by the joint action of a small engine cylinder or cylinders of its own, and the
oscillatory or reciprocatory motion of a connecting rod at right angles to that of
the small engine, and jointed, to the same crank (or equivalent cranks) on said
shaft; the connecting rod being jointed to and actuated by a lever (preferably
double armed) oscillating on a fixed centre on frame, and connected by a link and
joint to crosshead or other part of piston rod or reciprocating rod of main engine,
so as to be oscillated by this. A small back set crank may be keyed on the over-
hung end of crank pin of small engine to work its steam slide valve or other
equivalent.

page_text: When the large engine is worked by a main slide valve on face of ports, with
cut-off plates or "grid" or other valve on back, each valve would have an eccentric
mounted on small engine crank shaft for working it direct by a rod, or it might be
through an intermediate differential link that would give less or more throw or
stroke to its valve than that due to its eccentric.
Thus, this arrangement of valve-gear, with the eccentrics of right size and
properly set (as is well understood) on the crank shaft of small engine to give the
valves of the main engine their proper stroke and movements to suit their "lap"
and "lead" and the stroke of the piston in time to reverse it at each end of main
cylinder, the small engine always working at right angles on its crank and pin to
that of main engine, would always bring round the shaft and eccentrics in the
proper direction and time, when the connecting-rod of large engine (worked from
lever as stated) was at the extreme ends of its stroke (or dead points) in either
direction, to give the steam to the large engine to reverse it while the motion of
this rod of main engine, would always in like manner turn, or ensure the turning
of, the small engine past the two dead centres or points of its stroke or revolution,
until it got steam beyond its centre, even if cushioned before the end of stroke.
For
To give and regulate lead to main valve of large engine, sufficient notion or play
would be given by a shifting screw collar and lock-nut,-fitted on extreme end of
connecting-rod of large engine, where it is jointed to its moving lever,--to allow
the rod to be carried forwards by its crank on small engine shaft and motion of
small engine, to give the desired amount of steam at each end of stroke of main
valve and engine, fixed and regulated by said screw collar and jam nut.
double or compound cylinder engines, the crank shaft of small engine (actuated also
by the reciprocatory motion of main engine) would require to be lengthened to
extend over beyond the valve chest of second cylinder, and be fitted with an
eccentric for each valve of the second cylinder to get the same action and
distribution of the steam for it. And further, the position of small engine and its
shaft, and the position and direction of motion of lever and connecting-rod of main
engine would require to be slightly modified to suit the construction of engine,
such as horizontal or vertical, and the position of the valve chests and valves, but
the improvements would be substantially the same nevertheless. Thus when the
cylinders are horizontal and the valve chests and valves are on the top of cylinder,
the crank shaft with the eccentrics for working the valves would most con-
veniently be ranged horizontally some feet in front of valve chest to give room for
eccentric rods and links when these are used, and the small engine, and lever of
large engine which works the shaft would require to work vertically and at right
angles to each other from centre of shaft. And when the valve chest and valves
are on the side of a horizontal cylinder engine, the crank eccentric shaft would
preferably be placed and work vertically, which would necessitate the small
cylinder engine and the lever of main engine jointly driving said shaft, being
placed to work horizontally in a plane with their crank pin ou shaft, and at right
angles to each other from centre of shaft as before stated.
2007

page_text: BEZERUS.
We, THOMAS MCCULLOCH and DAVID MCCULLOCH, both of Vulcan Foundry,
Kilmarnock, Ayrshire, and THOMAS WHITE, of 5 Thomson Street, Govan, Lanark-
shire, Engineers, do hereby declare the nature of our said invention, and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement in writing, reference being had to the accom-
panying Sheet of Drawings, and to the letters and figures marked thereon, that is
to say:-
Our invention has reference to an improved combination or arrangements of
mechanism or gear for actuating the distributing valves of single or compound
cylinder steam or other fluid-pressure motive-power engines, and is specially
applicable to reciprocating or non-rotative engines, such as much used for working
pumps and air compressers direct, or through bellcrank or other levers, without
intermediate rotative crank shafts. These improvements are susceptible of slight
modification to suit the construction of engine and disposition of its valves and
valve chest, and they will enable the engines fitted with them to work more highly
expansively, more economically, and better and steadier than such engines, as
heretofore constructed, have done.
And in order that the nature and novelty of our said invention, and the manner
of carrying the same into effect or practice may be properly understood, we shall
now proceed to describe the several figures on the Sheet of Drawings, which we
have hereunto appended for that purpose; the same reference letters indicating the
same parts in all the figures.
Figures 1 and 2 are respectively a side elevation and a plan of a horizontal
single-cylinder direct-acting steam pump, constructed in accordance with the
improvements of our invention; and Figure 3 is a transverse section of this engine
taken on the line 1---1 in Figure 1.
This engine bas a single steam cylinder A, and pump cylinder B, both bolted
together in their true straight centre line at a proper distance apart, by the duplex
longitudinal side frame C, C¹, cast in one piece with the end covers A', B', of the
steam and pump cylinders A and B respectively; which covers also form the ends
of tliis framing C, C, of the engine, the whole being carried by broad-soled stool
supports A2, B, cast on the underside of these cylinders respectively, and bolted
down by screw bolts to a suitable stone or other foundation at Z--Z.
Referring to these Figures 1 to 3, the nature and novelty of our said invention
or improvements consist all as hereinafter described. When applied, as here
illustrated, to a horizontal steam engine with a single cylinder A, having its reci-
procating piston-rod a and that b of the pump B, passing out through their stuffing
boxes in their end covers A³, B₁, towards each other, and cottered or coupled to one
crosshead or socket arm D, D¹, which might have guide blocks guided in slides
formed on the inside faces C" of the frame C, C, all transmitting the power to
work the pump direct as stated. Our improvements mainly consist in the appli-
cation of a special small steam cylinder or engine E, with a crank shaft F, light
but strong enough for safely and effectively actuating the main and cut-off slide
valves a¹, a², in the steam casing A³, or it might be other valves, of the large

page_text: This
engine cylinder A, by eccentrics I, I, and their connecting rods I", 1ª.
shaft F for working the valves of the main engine in this arrangement, is preferably
mounted in bearing brackets C2 projecting up from the frames C, C, near the pump
end to give a good length to the eccentric and other rods actuated by and actuating
this shaft, which is driven in the proper direction indicated by the arrows in
Figure 1, by the joint action of the small cylinder E of its own,secured vertically
to the side frame C¹, below the overhung end and crank E¹ E³ and its connecting
rod E, and by the oscillatory or reciprocatory motion of a connecting rod or
rods F and their cranks F¹ acting at right angles to that E¹ of the small engine E,
when jointed to the same crank or cranks in line, as those F¹ and E¹ are (or other
equivalent cranks) on said shaft F. The connecting rods F' are jointed to and
actuated by the upper short double arms G of the levers G G¹ (preferably of the
double-armed or of beam lever form) secured to and oscillating on a rocking (or
fixed) shaft H carried in bush bearings H', in the frames C, C₁; and having the
lower long arms G' connected by links g, g, jointed to the centre g¹, secured in the
lower end of the bracket D', on the crosshead D, or other part of piston rods or
their continuation or other reciprocating rod of the main engine, so as to be
oscillated by or in uniform time with it. The slide steam, or other valve and its
rod e, e¹, of the small engine E, may be actuated by a small back set crank e³
keyed on the overhung end of the crank pin E³ in the crank E¹ of the small
engine E.
When the large engine A is worked by a main slide valve a¹ above on the face
of the ports, with cut off valve plates a³, (or a "grid" or other expansion valve)
worked on the back of the slide valve, then each rod a¹ or a² of these valves would
have an eccentric I, I', mounted on the crank shaft F of the small engine E for
working these valves direct. by their eccentric rods I" I², or it might be through an
intermediate differential link or other equivalent that would give less or more
throw or stroke to its valve than that due to its eccentric.
Thus, this arrangement of valve-gear with the eccentrics I, 11, of right size and
properly set (as is well understood) on the crank shaft F of the small engine E, to
give the valves a³, a³, of the main engine A their proper stroke and movements to
suit their "lap" and "lead" and the stroke of the piston in time to reverse it at
cach end of the main cylinder A; the small engine E always working at right
angles on its crank E¹ and pin E³ to those F¹, of the main engine, would always
bring round the shaft F and eccentrics I, I, in the proper direction and time,
when the connecting rods F2 of the large engine (worked from the lever arrange-
ment G, G, g, g¹, as stated) were at the extreme ends of their stroke (or dead
points) in either direction, to give the steam to the large engine to reverse it, while
the motion of the rods F' of the main engine, would always in like manner turn,
or ensure the turning of the small engine E past the two dead centres or points of
its stroke or revolution of its crank E¹, until it got steam beyond or after turning
these dead centres, even if cushioned to some extent before the end of the stroke.
To give and regulate the "lead" to the main valve a¹ of the large engine,
sufficient motion or 'play," as shown at f, would be given by a shifting screw
collar f¹ and lock nut f², fitted on the extreme ends of the connecting rods F¹ of
the large engine, where these are jointed by swivel blocks g² to the short upper
ends G of their moving levers G, G₁, to allow the rods F3 to be carried forward by
their cranks F' on the small engine shaft F and forward motion of the small
engine E, to give the desired amount of motion to the valves of and steam at each
end of the stroke of the piston of the main engine A, fixed and regulated by the
play allowed at f by the screw collar f¹ and jam nut f³. Washers of india-rubber,
or other equivalent, may be fitted on the face of the abutting collars on the ends of
the rods F, or faces of the joint blocks g², to soften the knock on these parts. The
position of the small engine E and its shaft F, and of the levers G G¹, and
connecting rods F2 of the main engine, and the direction of their motion, would
require to be slightly modified to suit the construction of the main engine and the
-position of the valve chest to which the improvements are to be applied. Thus,
"

page_text: when the position of the valve chest A³ and valves of the large engine, are placed
on the side of the cylinder A, instead of above, as described and shown in the
drawings, then this would necessitate the small cylinder engine E and the lever
arrangement G G₁ and their rods F2 of the main engine R, (jointly driving the
rotative eccentric shaft F) all being placed to work horizontally with their shafts F
and H placed vertically and in a plane with the motion of their cranks F¹ on the
shaft F, instead of vertically as shown in the drawing, but still at right angles to
each other from the centre of the shaft F as before stated, leaving the improve-
ments all substantially the same nevertheless; so as to work the valves of such
direct-acting reciprocating engines, by a small engine and its shaft (without a. fly-
wheel but by levers from the large engine at right angles to the small engine.
For double cylinder engines, or compound expansive engines, the crank shaft F
of the small engine E, (actuated also by the reciprocatory motion of the main
engine as herein described), would require to be lengthened to extend over beyond
the valve chest of the second cylinder of the main engine, and be fitted with a
suitable eccentric for each valve of this second cylinder, to get the same effective
action and distribution of the steam for it, described in reference to the first
cylinder. In some cases, when found more suitable, a separate small engine and
shaft may be used for the second cylinder of the main engine, and the shafts of the
two small engines might thus have their cranks at different angles to suit the
valves of their moving levers, and either the crank shafts of the small engines, or
the reciprocating crossheads of the main cylinders, might be connected for the two
engines to work in uniform time.
Although tliese improved mechanical arrangements of "gear" have only been
described, and shown in the Drawings, as applied to the working of the valves of
steam engines for giving a proper distribution of the steam thereto, it will be quite
evident to engineers and others that they are equally applicable to engines worked
by other pressure fluids, of the same direct-acting reciprocating non-rotative
construction.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is
CL
First. The general arrangement and combination of the parts of mechanism or
gear" for actuating the slide or admission valves of steam or other fluid pressure
direct acting non-rotative engines, substantially as herein described, and shown in
the accompanying Drawings.
Second. The construction or combination and adaptation of a small rotative
engine having its crank shaft actuated at right angles by a lever or levers and rods
from a main reciprocating non-rotative engine, for working the slide or admission
valves thereof, substantially as berein described, and shown in the accompanying
Drawings.
Third. In a non-rotative or direct-acting reciprocating engine, the combination
and-application of a lever or levers G, G₁, and connecting rods with "play" at
their connections to actuate a crank shaft for working the slide or inlet valves
of said engine, the crank shaft being also actuated at right angles by a small
engine therefor, substantially as herein described, and shown in the accompanying
Drawings.