CERTAIN IMPROVEMENTS IN STEAM. ENGINES.
Year: 1860

page_text: LETTERS PATENT to William Barker, of Cornbrook, in the City of Man-
chester, Engineer, for the Invention of "CERTAIN IMPROVEMENTS IN STEAM.
ENGINES.
Sealed the 27th March 1861, and dated the 11th October 1860.
PROVISIONAL SPECIFICATION left by the said William Barker at the
Office of the Commissioners of Patents, with his Petition, on the
11th October 1860:
I, WILLIAM BARKER, of Cornbrook, in the City of Manchester, Engineer,
do hereby declare the nature of the said Invention for "CERTAIN IMPROVE-
MENTS IN STEAM ENGINES," to be as follows:-
The object of this Invention is to regulate the velocity of steam engines
according to the load, and it consists in an improved combination of parts in
communication with the governor by means whereof the admission valve, the
slide valves, or the expansion valves are opened and closed, so as to admit
more or less steam to the engine.
In performing my Invention I make use of a circular rack on the bush of
the governor gearing in a segment, to which are jointed catches taking into a
wheel fixed to a lever; these catches move the lever in contrary directions,
and to the lower end of the lever is connected a rod which gives a to-and-fro
motion to a spiral cam; this cam and a tappet act together on the valve
spindle, and the valve is kept open for a greater or less portion of the piston's
stroke, according to the relative positions of the cam and tappet.
The details above given must be varied according to the peculiar con-
struction or arrangement of the engine to which the improvements are
applied.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Barker in the Great Seal Patent Office on the
11th April 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
BARKER, of Cornbrook, in the City of Manchester, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eleventh day of October, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-fourth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
William Barker, Her special licence that I, the said William Barker, my
executors, administrators, and assigns, or such others as I, the said William
Barker, 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 "CERTAIN IMPROVE-
MENTS IN STEAM ENGINES," upon the condition (amongst others) that I, the
said William Barker, 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 William Barker, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement (that is to say):-
The nature of this Invention consists in an improved combination of parts
in communication with the governor of a steam engine, by means whereof the
admission valves, the slide valves, or the expansion valves, are opened and
closed, so as to regulate the quantity of steam supplied to the engine in pro-
portion to the load or work to be performed.
And in order that my Invention may be fully understood and readily
carried into effect, I will proceed to describe the means pursued by me,
reference being had to the accompanying Sheet of Drawings, and to the
figures and letters marked thereon.
Figure 1 is an elevation of part of a steam engine to which my improvements
are applied; Figure 2 is an end view of the same; Figure 3 is another end

page_text: view shewn partly in section; and Figures 4, 5, 6, and 7 are detached views
of parts of my improvements.
a, a, are the balls of the governor, which are connected in the usual manner
to the sliding bush b, to the lower part of which is cast or fixed the circular
rack c gearing into the segment d, shewn detached in Figure 4; this segment
is loose on the stud e fixed in the pillar f, and to the upper part of the
segment d are fixed the studs g, g, for the catches h and i, both of which take
into the wheelj, which is cast with or fixed to the slot lever 7. This lever is
also loose on the stud e, but the flanges j forming the sides of the wheel j are
both fixed on the said stud; the flanges j have each a projection, as shewn
best in Figure 5, against which the catches h and i act; to the lower end of
the lever is jointed one end of the rod m, the other end of which is connected
to the spiral cam n, which is loose on the shaft o, and this shaft revolves at
the same speed as the governor shaft a', being driven by a pair of mitre wheels
marked a² and o¹, as shewn in Figure 1; in case the governor does not run at
the same speed as the engine, then the wheels a and o¹ must be made to
correspond with the difference in speed; the cam n is made with two diagonal
slots which fit on each side of a tappet q keyed on the shaft o, consequently
when the shaft revolves the tappet q carries the cam n round with it, and both
together act on the bowl r, which is connected to the rod s of the equilibrium
valve t; or the rod s may be connected to the ordinary slide valves, or to the
expansion valves of a steam engine. The Drawing represents the various
parts in the positions they occupy when the engine is working at its proper
speed; the governor balls are about at the centre of their course, and the
segment d holds the catches h and i in gear with the teeth of the wheel j, the
projections fitting between the said catches; the tappet 9 is about in the
centre of the spiral cam n, the two in revolving holding the valve t open the
requisite time for admitting the proper quantity of steam to the engine; as
soon, however, as the load on the engine increases and more steam is required,
the governor balls in collapsing lower the circular rack c, thereby turning the
segment d partly round in the direction of the arrow in Figure 1, in so doing
the catch h is drawn partly on to the projection, while the catch a drops into
gear with and moves the wheel j and lever 7 partly round, thereby pushing the
rod m and spiral cam n in the direction of the full arrow; the relative
positions of the cam n and tappet q are thus changed, and as the dwell on the
cam increases gradually from the point A to the end B, it is evident that when
the cam n has been moved in the direction indicated, the dwell is increased
and the valve is held open longer and admits more steam to the engine. The
section lines in Figure 3 shew the shape of the cam n at the end A, and the

page_text: detached section, Figure 7, represents the shape of the cam at the end B. As
soon as the engine regains its proper speed the governor balls a, the segment d,
and the other parts described, return to their original positions; the contrary
action takes place when, owing to the load on the engine being reduced, the
governor balls expand; in this case the catch i is drawn partly on to the
projection, and the catch h acting on the wheel j moves the lever l, rod m,
and spiral cam n in the direction of the dotted arrows, thereby reducing the
amount of steam admitted to the engine. I wish to remark that the machinery
shewn in communication with the governor for moving the rod m in contrary
directions, may be applied to conical or other cams now in use for regu-
lating the amount of steam admitted to the engine, or in some cases to the
valves.
In the foregoing description and Drawing I have shewn the spiral cam n
with two grooves, and the tappet q with two projections; it will, however, be
apparent that the cam can be made with a single groove, and the tappet with
only one projection; in this case the shaft o must be made to revolve at twice
the speed of the governor spindle, or at the proper speed for opening and
shutting the equilibrium or other valve at each end of the stroke of the
piston.
Having thus stated the nature of my Invention and described the manner
of performing the same, I wish to remark that I do not limit myself to the
details given, as they may be varied without departing from the peculiar
character thereof, and I declare that I claim as my Invention,-
First, the compound cam and tappet marked n and q when used in the
manner and for the purposes described.
And, secondly, the improved combination of parts shewn and described for
giving a lateral motion in contrary directions to the cam n, or to any other
apparatus for regulating the amount of steam admitted to the steam engine.
In witness whereof, I, the said William Barker, have hereunto set my
hand and seal, this Eighth day of April, in the year of our Lord One
thousand eight hundred and sixty-one.