IMPROVEMENTS IN APPARATUS FOR REGU- LATING THE ADMISSION OF STEAM TO THE CYLINDER OF A STEAM ENGINE BY THE ACTION OF THE GOVERNOR
Year: 1871

page_text: LETTERS PATENT to Charles Denton Abel, of No. 20, Southampton
Buildings, Chancery Lane, in the County of Middlesex, Patent
Agent, for the Invention of "IMPROVEMENTS IN APPARATUS FOR REGU-
LATING THE ADMISSION OF STEAM TO THE CYLINDER OF A STEAM ENGINE
BY THE ACTION OF THE GOVERNOR." -A communication from abroad by
Alphonse Rycx, residing in Ghent, in the Kingdom of Belgium.
Sealed the 23rd February 1872, and dated the 20th December 1871.
PROVISIONAL SPECIFICATION left by the said Charles Denton Abel
at the Office of the Commissioners of Patents, with his Petition,
on the 20th December 1871.
I, CHARLES DENTON ABEL, of No. 20, Southampton Buildings,
Chancery Lane, in the County of Middlesex, Patent Agent, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN APPARATUS
FOR REGULATING THE ADMISSION OF STEAM TO THE CYLINDER OF A STEAM ENGINE

page_text: steam admitted to the cylinder of a steam engine is regulated by the
action of the governor on a cut-off or expansion valve or slide.
As
Instead of rigidly connecting to the cut-off or expansion slide the
excentric or cam rod employed to work it, the excentric or cam rod is
made to terminate in a socket in which the slide rod is free to slide.
On the slide rod are formed two grooves; one side of each groove is cut
at right angles to the axis of the rod, and the other side of the groove is
gradually sloped off, so that the two grooves present as it were two
circular ratchet teeth on the rod which are made to face opposite ways.
On the socket in which this doubly grooved rod slides are mounted two
pawls facing opposite ways, the ends of which pass through slots in the
side of the socket. These pawls are pressed by springs against the
grooved rod, so that whenever one of the grooves is is presented to the
one pawl it is caused to engage in the groove, and when the other groove
is presented to the other pawl it also engages in it in like manner.
the pawls and grooves face opposite ways the one pawl when it engages
in its groove while the excentric or cam rod is moving in one direction
causes the slide rod to move with it, but when the excentric or cam rod
moves in the opposite direction this pawl merely slides along the sloping
side of the groove without giving movement to the slide or valve rod;
and the other pawl acts in a similar manner in its groove but in the
reverse directions of movement. The slide rods has collars on it with a
spring so set between them that whenever the rod is free to move the
spring brings it to its middle position. Each pawl has a tail piece
projecting from it, and between these tail pieces there is a spindle on
which a cone is fitted to slide to and fro in a direction transverse to the
line of movement of the excentric or cam rod. This cone is moved
along the spindle by the action of an ordinary governor, the connections
to the governor being so arranged that whenever the speed increases a
larger part of the cone is made to come between the tails of the pawls.
The cut-off or expansion slide, which is by preference employed in con-
nection with this apparatus, is a slide made with several passages
through it, working on a face which has several corresponding openings.
When this slide is in its middle position all the openings are closed by
it, but a little movement in either direction serves to uncover the several
openings and thereby to allow the full passage of steam to the ordinary
working slide or valves of the cylinder.

page_text: The
The action of the apparatus is as follows:-When the excentric or
cam used for working the cut-off is at the middle of its stroke and the
expansion slide is also in its middle position shutting off the steam
supply from the engine cylinder, neither of the pawls is engaged in a
groove of the slide rod. As the excentric or cam moves its rod and the
socket and pawls in one direction, one of the pawls being brought
opposite to one of the grooves in the slide rod engages in it, and when
by the revolution of the excentric or cam the movement of the excentric
or cam rod is reversed this pawl being against the abrupt side of the
groove moves the slide rod and the slide so as to admit steam to the
cylinder, such movement being properly timed by the stroke of the
piston by the setting of the excentric or cam on the engine shaft.
movement of the slide by means of the pawl continues until the tail of
the pawl bears against the cone, which has the effect of disengaging the
pawl from the groove and so leaving the slide rod free. The spring
acting on the slide rod immediately restores the slide to its middle
position and so cuts off the steam supply. The action of the other pawl
is similar, but arranged for the movement of the excentric or cam rod in
the opposite direction. It is evident that the larger the part of the cone
which is brought within the range of the tails of the pawls the sooner
in the stroke of the pawls are they disengaged from the grooves of the
slide rod, that is to say, the sooner is the steam supply cut off. As the
governor the more rapidly it revolves causes the larger part of the cone
to be presented to the pawls the governor is by this apparatus caused to
act on the slide so as to regulate the cut off, thus admitting less steam
or steam for a less time to the cylinder the greater its velocity of
rotation. To the regulating cone above described another cone facing
the opposite way may be attached, the object being that should the
governor by any accident cease to revolve, this second cone shall come
between the tails of the pawls, and so prevent them from engaging in
the grooves of the slide rod, the steam supply being thus entirely cut off
and the engine stopped.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles Denton Abel in the Great Seal Patent
Office on the 19th June 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
DENTON ABEL, of No. 20, Southampton Buildings, Chancery Lane, in
the County of Middlesex, Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twentieth day of December, in the
year of our Lord One thousand eight hundred and seventy-one, in the
thirty-fifth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Charles Denton Abel, Her special
licence that I, the said Charles Denton Abel, my executors, adminis-
trators, and assigns, or such others as I, the said Charles Denton
Abel, 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 Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN APPARATUS FOR REGULATING THE ADMISSION OF STEAM TO THE
CYLINDER OF A STEAM ENGINE BY THE ACTION OF THE GOVERNOR," a communi-
cation to me from abroad by Alphonse Rycx, residing in Ghent, in
the Kingdom of Belgium, upon the condition (amongst others) that I,
the said Charles Denton Abel, 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 Charles Denton Abel, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement, reference being had to the Drawing
hereunto annexed, and to the letters and figures marked thereon
(that is to say) :-
These improvements relate to apparatus whereby the quantity of

page_text: steam admitted to the cylinder of a steam engine is regulated by the
action of the governor on a cut-off or expansion valve or slide.
pawl when it engages in
moving in one direction
the excentric or cam rod
Instead of rigidly connecting to the cut-off or expansion slide the
excentric or cam rod employed to work it the excentric or cam rod is
made to terminate in a socket in which the slide rod is free to slide. On
the slide rod are formed two grooves, one side of each groove is cut at
right angles to the axis of the rod, and the other side of the groove is
gradually sloped off, so that the two grooves present as it were two
circular ratchet teeth on the rod, which are made to face opposite ways.
On the socket in which this doubly grooved rod slides are mounted two
pawls facing opposite ways, the ends of which pass through slots in the
side of the socket. These pawls are pressed by springs against the
grooved rod, so that whenever one of the grooves is presented to the one
pawl it is caused to engage in the groove, and when the other groove is
presented to the other pawl it also engages in it in like manner. As the
pawls and grooves face opposite ways the one
its groove while the excentric or cam rod is
causes the slide rod to move with it, but when
moves in the opposite direction this pawl merely slides along the sloping
side of the groove without giving movement to the slide or valve rod.
And the other pawl acts in a similar manner in its groove, but in the
reversed directions of movement. The slide rod has collars on it with a
spring so set between them than whenever the rod is free to move the
spring brings it to its middle position. Each pawl has a tail piece
projecting from it, and between these tail pieces there is a spindle, on
which a cone is fitted to slide to and fro in a direction transverse to the
line of movement of the excentric or cam rod. This cone is moved
along the spindle by the action of an ordinary governor, the connections
to the governor being so arranged that whenever the speed increases a
larger part of the cone is made to come between the tails of the pawls.
The cut-off or expansion slide, which is by preference employed in
connection with this apparatus, is a slide made with several passages
through it, working on a face which has several corresponding openings.
When this slide is in its middle position all the openings are closed by it,
but a little movement in either direction serves to uncover the several
openings, and thereby to allow the full passage of steam to the ordinary
working slide or valves of the cylinder.

page_text: The action of the apparatus is as follows: -When the excentric or
cam used for working the cut-off is at the middle of its stroke and the
expansion slide is also in its middle position shutting off the steam
supply from the engine cylinder, neither of the pawls is engaged in a
groove of the slide rod. As the excentric or cam moves its rod and the
socket and pawls in one direction, one of the pawls being brought
opposite to one of the grooves in the slide rod engages in it, and when
by the revolution of the excentric or cam the movement of the excentric
or cam rod is reversed this pawl being against the abrupt side of the
groove moves the slide rod and the slide so as to admit steam to the
cylinder, such movement being properly timed to the stroke of the
piston by the setting of the excentric or cam on the engine shaft. The
movement of the slide by means of the pawl continues until the tail of
the pawl bears against the cone, which has the effect of disengaging the
pawl from the groove and so leaving the slide rod free. The spring
acting on the slide rod immediately restores the slide to its middle
position and so cuts off the steam supply. The action of the other pawl
is similar, but arranged for the movement of the excentric or cam rod in
the opposite direction. It is evident that the larger the part of the cone
which is brought within the range of the tails of the pawls the sooner in
the stroke of the pawls are they disengaged from the grooves of the slide
rod, that is to say, the sooner is the steam supply cut off. As the
governor the more rapidly it revolves causes the larger part of the
cone to be presented to the pawls the governor is by this apparatus
caused to act on the slide so as to regulate the cut-off, thus admitting
less steam or steam for a less time to the cylinder the greater its velocity
Fig. 1 represents a section of the steam and expansion slide of an 35
engine, with an elevation of apparatus, constructed according to this
Invention for working the expansion slide and regulating the cut-off by

page_text: the action of the governor; Fig. 2 represents a section of this apparatus
with a back view of the expansion slide.
A is a rod worked with reciprocating motion by a cam or excentric on
the engine shaft, timed so as to begin the stroke of the rod A in either
direction when the steam piston is at each end of its stroke; B is a
socket or tube fixed to the rod A, and enclosing within it the rod C of
the expansion slide D, this rod being fitted to slide freely within the
socket B. There are two grooves E and F formed in the rod C of a
ratchet form, and the upper part of the rod C is joined to the lower part
C¹ by screwing them together at L; two collars J, J, and a helical
spring K being placed on the rod within a tubular casing K¹ having at
cach end a stop for the collars J, J, in such a manner that if the rod C
be pushed upwards or downwards the helical spring K acting on the
collars J, J, brings them back against the stop ends of the casing, when
the rod C is left free to move. The rod C¹ is attached to the expansion
slide D in the ordinary way, or it may have adjusting nuts M, as shewn
in the Figures, so that this slide covers its ports W when the collars J, J,
are against the ends of the casing K¹. The two pawls H and H¹ are
mounted on the socket B, their ends projecting through slots in the side
of the socket so as to bear against the rod C. Springs I and I¹ press the
pawls upwards against the periphery of the rod C. The pawls H, H',
have tails hand h¹ projecting outwards. Between those tails is fixed a
spindle N on which is fitted a conical boss P free to slide to or fro on
the spindle N. A bell-crank lever O has one arm connected to the
governor by a rod R, and the other arm has a fork Q which engages
between collars on the conical boss P. When by the action of the
governor revolving with greater rapidity the rod R is drawn upwards,
the conical boss P is by means of the bell crank ○ pushed along the
spindle N so that a larger part of it is presented to the tails h, h³, and
when on the other hand the rod R is allowed to descend by the action of
the governor revolving with less rapidity, a smaller part of the conical
boss P is presented to the tails h, h¹. Beyond the smallest part of the
conical boss P it is advantageous to add a part P¹, coned in the opposite
direction. If by accident the governor should cease to revolve, or the
connections from it to the bell crank O should be broken, the crank
arm O falls by its own weight, and thus brings the large part of P¹
between the tails h, h³, causing the engine to stop, as will hereafter be
described.

page_text: A very
The expansion slide D may be of ordinary construction, but in order
to secure rapidity of action it is preferred to be of the kind represented
in the Drawings, that is to say, to consist of two or more D pieces
connected together, each of which is applied to a port W.
small movement of such a slide exposing passages at both edges of
each port permits a supply of steam to enter with great rapidity
into the slide jacket of the cylinder, and effects the cut-off with similar
rapidity.
The action of the apparatus is as follows:-The expansion slide D
being in its middle position closing the ports, the rod A and socket B
move forward till one of the pawls H or H¹ passing over the shoulder of
the groove E or F is caused to drop into the groove by the action of
the spring I or I¹. When the rod A. and socket B move backwards, the
pawl being engaged in the groove of the rod C brings that rod with the
socket, and thereby moves the slide D so as to give passage for steam to 1
the cylinder. This movement of the slide D continues until the
tail I or I¹ of the engaged pawl meets the conical boss P, which causes
the pawl to be disengaged from the groove and thereby leaves the rod C
free, and the spring K immediately brings the rod and slide back to
their middle position, and thereby closes the ports of the slide and cuts ?
off the steam supply. It is obvious that the larger the part of the
conical boss P that is interposed between the tails h, h¹, the sooner is
each of the pawls disengaged, and therefore the sooner is the steam
supply cut off. If then the governor begins to revolve with too great
rapidity it pulls up the rod R and pushes the boss P along the spindle 2
until it brings a larger part of the boss between the tails of the pawls
and thereby effects an earlier cut off of the steam supply. And on the
other hand, should the governor begin to revolve too slowly the rod R
drops, and the boss P presenting a smaller part to the tails of the pawls
allows the steam supply to be maintained during a greater period of the
stroke. As the reverse cone P¹ is provided only in case of accident to
the governor or its connections it may be dispensed with. Also the
cone P may be elongated, and the collars between which the fork Q
engages may be at either end of the cone to suit the position of the
governor. It is sometimes advantageous to interpose in some convenient
part of the connections from the governor to the sliding boss P a spring
or oil cylinder so as to avoid suddenness of movement.
Having thus described the nature of this Invention and in what
Having thus described the nature of this Invention, and in what

page_text: manner the same is to be performed, as communicated to me by my
foreign correspondent, I claim,-
First. The use of apparatus for regulating the admission of steam to
the cylinder of a steam engine by the action of the governor, substantially
as herein described.
Second. The use in such apparatus of an expansion or cut-off slide
consisting of several connected D slides operating on several corre-
sponding ports, substantially as herein described.
In witness whereof, I, the said Charles Denton Abel, have hereunto
set my hand and seal, this Thirteenth day of June, in the
year of our Lord One thousand eight hundred and seventy-two.