tain Improvements in Steam Engines, and in Centrifugal Governors for Steam Engines.
Year: 1890

page_text: Date of Application, 19th Nov., 1890
Complete Specification Left, 19th Aug., 1891-Accepted, 19th Sept., 1891
PROVISIONAL SPECIFICATION
Certain Improvements in Steam Engines, and in Centrifugal
Governors for Steam Engines.
We, THOMAS SMITH, WILLIAM HILL SMITH, and WILLIAM EASTWOOD,
rading as Smith Brothers and Eastwood, of Soho Works, Thornton Road,
Bradford, in the County of York, Engineers and Millwrights, do hereby declare the
ature of this invention to be as follows:-
Our invention has reference to high or low speed steam engines and other
notors, suitable for driving dynamos, circular saws, printing and other machinery,
the improvements therein relating to the distribution and cut-off valves.
The objects of our invention are:-Firstly, to obtain a quick cut-off; and,
secondly, to reduce to the smallest possible volume the clearance-space, thereby
diminishing the waste of steam which happens with a large clearance-space, making
it detrimental to the economical working of engines, especially in single cylinder
engines.
We attain our first object by making the necessary steam inlet or port area of
great length, in comparison with its width in the direction of stroke of valve, thus
ensuring a quick cut-off with a very short stroke of valve, and also rendering the
valve more easily controlled by the governor. For this purpose, we form an annular
or other suitable shaped chamber around the outside of the cylinder, in which
chamber is made to work a circular ring or piston. This may be either a
distribution valve of constant stroke, whose function is to release steam to exhaust,
with a cut-off valve on the outside of variable stroke, controlled by governor; or it
In the
may be a distribution valve of variable stroke controlled by governor.
former case, the distribution and cut off valves may have, either, each a
reciprocating motion; or, the one a reciprocating motion, and the other a rotary
motion, controlled by governor. In the case of the distribution valve alone, it may
have a reciprocating motion of constant stroke to control exhaust, and a rotary
motion controlled by governor to vary cut off.
Our second object is attained by the following means:-The steam ports consist
of openings formed around the periphery of the cylinder, the capacity of the said
ports, or the clearance, being the product of a fraction of the circumference of the
cylinder, the width of ports, and thickness of cylinder, which is practically
nothing in comparison with the contents of the cylinder. By this arrangement we
effect a great saving of steam over other piston and ordinary slide valves.
The valves described above may be applied to both single and double acting
engines of all descriptions, and also to steam hammers.
Our invention has reference also to centrifugal governors, our object being to
provide an efficient governor to alter the stroke of eccentric for working the valve,
and to advance its position to obtain the most suitable lead opening. For this
purpose we employ two eccentrics, one of which (the valve eccentric) is mounted
on a loose block on the fly wheel shaft, the said block acting as a bearing for
eccentric against shaft, and fitting into a corresponding slot in valve eccentric, thus
allowing valve eccentric to slide when by action of governor weights it is
required to move outwardly or inwardly, to increase or diminish stroke. The block
being loose on fly wheel shaft, allows centre of valve eccentric to be at the same
time advanced round shaft. The other eccentric is formed by a portion of the fly
it may
wheel boss being turned eccentrically to the fly wheel shaft; or
be keyed to fly wheel boss, or fly wheel.shaft, with centre at a suitable
point between centre of fly wheel shaft and centre of cylinder in direct
acting engines. On this eccentric is a. strap carrying a pin or stud which

page_text: nts into and controls the valve eccentric previously mentioned
mounted on the block. When the strap is moved around the eccentric boss of fly
as being
wheel, the pin moves in an arc of a circle, with centre (i.e., centre of fast eccentric)
in such a position as to make the pin, and therefore valve eccentric connected to it,
approach centre of fly wheel shaft, thus reducing the stroke, and at the same time
taking the eccentric round to the necessary angle of advance to ensure suitable
lead opening. The valve eccentric is thus moved from its maximum stroke, which
cuts off steam at stroke of piston, to its minimum stroke, which just opens steam
inlet, or to any point between these limits. By this means the valve eccentric is
adjusted in position to cut off steam at any point of the stroke of engine to suit the
load upon it within its power. As the governor weights fly out by centrifugal
force, they are balanced in every position of their range of movement by springs;
the movement of the weights being communicated by suitable levers, pivots, and
links to the strap on eccentric on boss of fly wheel, the pin in strap adjusting
valve eccentric as previously explained, and for previously explained purpose.
Instead of the fast eccentric and strap with pin, whose purpose is to control valve
eccentric, we may use a lever pivoted at the desired point, with a pin engaging
with and controlling said eccentric.
Dated this 18th day of November 1890.
TASKER & CROSSLEY,
Halifax, Agents.
COMPLETE SPECIFICATION.
Certain Improvements in Steam Engines, and in Centrifugal
Governors for Steam Engines.
We, THOMAS SMITH, WILLIAM HILL SMITH, and WILLIAM EASTWOOD,
trading as Smith Brothers and Eastwood, of Soho Works, Thorntou Road,
Bradford, in the County of York, Engineers and Millwrights, 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 invention has reference to high or low speed steam engines and other motors,
suitable for driving dynamos, circular saws, printing and other machinery, the
improvements therein relating to the distribution and cut-off valve, and to the
governors regulating the same.
The objects of our invention are, firstly, to obtain a quick cut-off; and, secondly,
to reduce to the smallest possible volume the clearance space, thereby diminishing
the waste of steam which happens with the large clearance space, which is more or
less unavoidable in engines of other types; thirdly, to effectively and automatically
control the engine so as to run with a minimum variation of speed.
In order that our invention may be more clearly understood, we will now make
reference to the accompanying sheets of drawings illustrative thereof, wherein Fig. 1,
Sheet 1, is elevation, partly in section of a vertical single acting steam engine; and
Fig. 2 is plan, partly in section, through ports.
cylinder. Our improvements in this class of engine consist in placing a casing B
A represents the steam engine
around the end of the steam cylinder A. in such a manner as to leave or form an
annular chamber or steam chest, in which is made to work a ring or piston valve C,
receiving reciprocating motion, by means of rods D, from the "moveable eccentric,'
hereinafter described, on the crank shaft. Steam is introduced into the annular
chamber B at E, whilst F is the exhaust. The inlet ports of the cylinder A are
composed of slits or apertures G formed around the body of the cylinder, as shewn
clearly in Figs. 1 and 2, and as by this means we are enabled to utilize a much
larger portion of the circumference of the cylinder than is possible in the case of
ordinary slide valves with plain face, it follows that the width of the ports in the
direction of the length of the cylinder is smaller by the same proportion. We thus
obtain a steam inlet area of maximum length and minimum width, consequently the

page_text: Stroke of the valve is short and the cut-off quick.
formed in a like manner to the inlet ports, the steam being led away by conduit .J
The exhaust ports H. are
to the exhaust chamber F.
By the use of the narrow inlet ports, we dispense with the large waste space
5 hitherto incidental to engines worked with piston or slide valves.
The other part of our invention has reference to centrifugal governors, our
object being to provide an efficient governor to alter the stroke of eccentric for
working the valve, and to advance its position to obtain the most suitable "lead"
opening. This part of our invention is shewn on Sheet 2, where Fig. 3 is elevation
and Fig. 4 is cross section of our improved construction of centrifugal governor.
A represents a wheel, and B the fly wheel shaft. We employ two eccentrics, one of
which, C, is the valve eccentric, and it is mounted on a loose block D on the fly
wheel shaft, the said block acting as a bearing for the eccentric against the shaft.
This block is square on the outer surface, and fits into a corresponding slot formed
in the eccentric. The said slot is made longer in one direction in order that the
eccentric may slide upon the block, when by the action of the governor weights E,
it is required to move outwardly or inwardly to increase or diminish the stroke of
the cut-off valve, and as the block D is loose on the fly wheel shaft, it allows_the
centre of the eccentric C to be advanced at the same time around the shaft. The
other eccentric is shewn at F, and around it is a strap G carrying a pin or stud H
which fits into and controls the valve eccentric C. The centre M of eccentric F
is located in such a manner, that when the strap is made, by the action of the
weights E and links K, to rotate from the position shewn on the drawing, the pin H
follows the path H N; and as it approaches the centre line of the engine,
marked O O, the motion of the valve eccentric C is reduced, its centre being
altered from point P for the maximum stroke to point R for the minimum stroke.
Simultaneously with this reduction of stroke, the eccentric is advanced to ensure
suitable lead opening. The balance weights E are pivoted at fulcrum J and are
connected to the eccentric strap G by means of the links K and pins Q, so that
on motion being imparted to the fly wheel, the centrifugal force of the weights E
is balanced by the springs L at every different radius in their range of movement.
This action of the governor controls the engine so as to run with a minimum
variation from a constant speed, the variation permitted being sufficient to entirely
cut off communication with the boiler. Thus the governor, by adjusting the valve
eccentric C to cut off the steam from () to stroke, automatically controls the
admission of steam suitable for any load from no load to full load.
Having now particularly described and ascertained the nature of our said inven-
ion, and in what manner the same is to be performed, we declare that what we
claim is :-
Firstly. In high or low speed steam engines or other motors, the formation of
dmission and exhaust ports round the body of the cylinder as described.
Secondly. In high or low speed steam engines or other motors, the formation
of admission and exhaust ports round the body of the cylinder in combination with
n annular valve constructed and operated in the manner substantially as herein
hewn and described and for purposes set forth.
Thirdly. In a centrifugal governor, the combination of the weights, links, levers,
nd springs, with the fast and loose eccentrics, the strap of the former having a
otating movement, which carries with it the loose eccentric, at the same time
ausing the latter to slide radially on loose block as described.
Dated this 18th day of August. 1891
TASKER & CROSSLEY,
Halifax, Agents.