AN IMPROVED MODE OF WORKING THE SLIDE VALVES OF STEAM ENGINES
Year: 1873

page_text: LETTERS PATENT to John Ridyard Bennett, of Farnworth, in the
County of Lancaster, Engineer, for the Invention of "AN IMPROVED
MODE OF WORKING THE SLIDE VALVES OF STEAM ENGINES."
Sealed the 9th December 1873, and dated the 9th June 1873.
PROVISIONAL SPECIFICATION left by the said John Ridyard Bennett
at the Office of the Commissioners of Patents, with his Petition,
on the 9th June 1873.
I, JOHN RIDYARD BENNETT, of Farnworth, in the County of Lan-
caster, Engineer, do hereby declare the nature of the said Invention
for "AN IMPROVED MODE OF WORKING THE SLIDE VALVES OF STEAM ENGINES," to
be as follows:
This Invention relates to the ordinary slide valves of steam engines,
and consists in improved arrangements and movements for giving the
valve a variable traverse and expansion motion by the action of the
ordinary governor.
The valve rod is connected to an arm jointed to the framework of the
engine, the arm having a guide or slot, in which is fitted a block at the

page_text: end of the rod of an ordinary eccentric, which rod is connected by a link
to one end of a double lever, having at its other end a nut fitted to a
screw, having at one end a friction wheel between two discs, which
revolve with the governor rod, but can move up and down, according to
the contraction or expansion of the balls of the governor.
When the governor balls are expanded they raise the discs, causing
one to turn the screw in one direction and give such motion to the
double lever that the block at the end of the eccentric rod shall be
moved farther from the fulcrum of the slotted arm, and thereby enable
the eccentric to give less traverse to the slide, but when the governor
balls contract the other disc acts upon the friction wheel and reverses
the screw, so as to bring the block nearer to the fulcrum, and thereby
give greater traverse to the slotted arm and slide, and thus as the
governor balls expand or contract, according to the speed of the engine,
the traverse of the valve is so regulated as to give less or more steam,
and cut it off as required.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Ridyard Bennett in the Great Seal Patent
Office on the 9th December 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN 1
RIDYARD BENNETT, of Farnworth, in the County of Lancaster, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Ninth day of June, in the year
of our Lord One thousand eight hundred and seventy-three, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said John Ridyard Bennett,
Her special license that I, the said John Ridyard Bennett, my
executors, administrators, and assigns, or such others as I, the said
John Ridyard Bennett, my executors, administrators, and assigns,
should at any time agree with, and no others, from time to time and
at all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United

page_text: Kingdom of Great Britain and Ireland, the Channel Islands, and Isle
of Man, an Invention for "AN IMPROVED MODE OF WORKING THE SLIDE
VALVES OF STEAM ENGINES," upon the condition (amongst others) that I,
the said John Ridyard Bennett, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said John Ridyard Bennett, do
hereby declare the nature of my said Invention, and in what manner
the same is to be performed, to be particularly described and ascer-
tained in and by the following statement, reference being had to the
Figures on the accompanying two Sheets of Drawings, and to the letters.
of reference marked thereon (that is to say) :-
This Invention relates to the ordinary slide valves of horizontal and
vertical steam engines, and consists in an improved mode with modified
arrangements and combinations of mechanical movements for giving the
valve a variable traverse and expansion motion by the action of the
ordinary governor.
In one arrangement the valve rod is connected to an arm jointed to
the framework of the engine, the arm having a guide or slot, in which
is fitted a block at the end of the rod of an ordinary eccentric, which
rod is connected by a link to one end of a double lever, having at its
other end a nut fitted to a screw, fixed at one end to a friction wheel
between two discs, which revolve with the collar or boss of the governor,
and move up and down with it, according to the contraction or expansion
of the balls of the governor.
In other or modified arrangements I dispense with the link and
double lever between the nut on the screw and the block at the end of
the eccentric rod, and connect the block direct with the nut or screw
by slings or rods, and as these modified arrangements lessen the number
of parts and work with less friction I confine myself to giving a detailed
description of them only.
On Sheet 1 Fig. 1 is an elevation, and Fig. 2 a plan of one arrange-
ment or mode of applying my improvements to a beam or horizontal

page_text: steam engine; and on Sheet 2 Fig. 3 is an elevation, and Fig. 4 a plan
of an arrangement or mode adapted for a vertical engine.
In all the Figures a represents part of the steam cylinder of the
engine; b, the valve box; c, the valve rod; d, the crank shaft; e, the
eccentric; f, the eccentric rod; and 9, the governor.
In Figs 1 and 2 the valve rod c is connected to an arm i fixed on an
ordinary rocking shaft k, at one end of which is fixed an arm 7 having
a long slot m, in which is fitted a block n jointed to the end of the
eccentric rod f. The block n is connected by rods o to a screw p fitting
a nut in the bevil wheel a working in the bearing r, and gearing into
another bevil wheels at one end of the shaft t, to the other end of which
is fixed a friction wheel u between two discs v, w, fixed to the collar or
boss x, so that they can revolve with the governor and move up and
down according to the expansion and contraction of the balls. As the
eccentric e revolves the eccentric rodf and block n give more or less
traverse to the arm i and valve rod c, according to the position of the
block in the slot m, the position being regulated by the movements of
the governor.
When the governor balls are contracted, as in Figs. 1 and 2, the
discs v, w, are lowered, the upper one coming in contact with the
friction wheel u, the effect of which is to turn the shaft t, bevil
wheels 9, 8, and nut so as to raise the screw p, rods o, to bring the block
nearer to the fulcrum or to the centre of the rocking shaft, and thereby
give greater traverse to the valve.
When the governor balls are expanded they raise the discs v, w, the
lower one coming in contact with the friction wheel u, so as to turn the
shaft t and bevil wheels 9, 8, and nut in a reverse direction, and thereby
increase the distance of the block from the centre of the rocking shaft
and give less traverse to the valve, and thus as the governor balls
expand and contract, according to the speed of the engine, the traverse
of the valve is so regulated as to give less or more steam, and cut it off
as required.
In Figs. 3 and 4, representing the application of my improvements to
a vertical steam engine, the valve rod c is connected to an arm a¹ jointed
to the framework 6' fixed to pillars c¹, the arm having a guide or slot d',
in which is fitted a block e¹ at the end of the eccentric rod f. The block

page_text: is connected by rods f¹ to a cross bar or head g³, having in it a nut h³,
to which is fitted a screw 2 connected to the friction wheel ¹ between
two discs, m³, fastened to the collar or boss n¹ of the governor on
the shaft o geared by toothed wheels and shaft p¹ with the crank
shaft d.
The action of this arrangement is similar to that before described, for
when the speed of the engine is slightly retarded the upper disc / acts
on the friction wheel, and thereby turns the screw so as to bring forward
the nut g¹ and rods f¹, and place the block e¹ nearer the fulcrum, and
give a greater traverse to the valve, but when the speed of the engine is
on the increase the other disc m¹ comes in contact with the friction
wheel k¹, and turns the screw in a reverse direction, so as to remove
the block further from the fulcrum and give less traverse to the valve.
The friction wheel is mounted with leather or other friction material,
and in practice is nearly close to the discs when the engine is working
at its required speed, but the instant the speed is retarded by an increase
of the load on the engine, by a decrease of steam or other cause, the
friction wheel is turned by one of the discs so as to cause the valve to
have a greater traverse, but if by any means the speed of the engine is
increased the other disc reverses the friction wheel and causes the valve
to have less traverse, and if the motion of the nut h', Figs. 3 and 4, is
so extended as to get off the screw it is again put on by the spring q³,
when the motion of the screw is reversed, and the spring also keeps the
nut up to its work, and to counterbalance the weight of the governor
and parts connected with it there is a weighted lever st, Figs. 1 and 4,
and it will be seen that the ordinary throttle valve is entirely dispensed
with.
Having now described the nature and particulars of my said Inven-
tion, I desire it to be understood that for working the slide valves of
steam engines I do not claim the several parts of the arrangements and
combinations taken separately, for discs, friction wheels, and screws
have been before used in connection with throttle valves and governors,
and the slotted arm in connection with the eccentric rod have been
used without the governor, but what I do claim is the improved arrange-
ments and combinations of the several parts, such as the governor, the
discs, the friction wheel, the screw and nut, the slotted arm, the block
at the end of the eccentric rod, and also the connections between the

page_text: block and the screw or nut for enabling the governor to give variable
traverse motion to the slide valve, according to the pressure of the steam
in the boiler or the load on the engine, as such improvements are herein
described and illustrated on the accompanying two Sheets of Drawings,
or any mere modification thereof.
In witness whereof, I, the said John Ridyard Bennett, have here-
unto set my hand and seal, this Eighth day of December, in
the year of our Lord One thousand eight hundred and seventy-
three.