An Improvement in Governing Gear for Steam Engines.
Year: 1896

page_text: C
Date of Application, 1st Apr., 1896
00th Doe 1905 Accented 6th Mar. 1897
PROVISIONAL SPECIFICATION.
An Improvement in Governing Gear for Steam Engines.
I, CHARLES HORACE BENTON, 46 St. Michael's Road Headingley, Leeds, Engineer,
do hereby declare the nature of this invention to be as follows:-
My invention relates to that form of steam engine in which the steam is supplied
to the cylinder through a hollow trunk attached to the piston. In these engines a
trunk works through a gland into the steain chest, and has ports in its circumference.
The end of the trunk in the steam chest is closed. The ports in the trunk therefore
form the only means of communication between the steam chest and the cylinder.
At the beginning of the stroke of the engine, the steam flows into the cylinder and
continues until the ports in the trunk pass through the gland. The steam is then cut
off, and the piston is driven to the end of the stroke by the expansion of the steam.
The distribution of the steam: otherwise than here described, is effected by a slide
valve werking within the hollow trunk. I utilize this cut-off as a means of governing
the speed of the engine in the following manner: I make ports in the trunk opposite
to each other at such a distance beyond the gland when the piston is at the beginning
of the stroke as will give the latest cut-off desired. I then fix plates opposite to each
other in the steam chest, against the sides of which slide the sides of the trunk in
which the ports are cut. These fixed plates are cut through by several passages
which correspond in width on the inner side to the ports in the trunk.
The passages are arranged in the line of stroke o the engine, and their aggregate
length extends over such proportion of the stroke as will give the limits of expansion
required. On the outsides of the stationary plates I arrange movable plates under
control of the governor of the engine, or to be moved by hand, which will close the
passages in the stationary plates, giving an earlier or later cut-off, as the passages
closed by the movable plates are farther from, or nearer to the engine cylinder.
These opposite movable plates are rigidly connected to each other by bars or stays
extending between them outside the trunk. When the pressure within the trunk
therefore is less than the pressure in the steam chest, the pressure of the steam upon
one movable plate, which would press it up to the face of the fixed plate, is conveyed by
these bars to the other movable plate. As the pressures upon the two movable plates
are in opposite directions, they neutralize each other through the bars, and leave
the plates in equilibrium.
In order that a slight movement of these movable cut-off plates may make a
considerable difference in the degree of expansion, I make the divisions between the
passages radiate from a common centre the outer ends of the passages being much
shorter in the direction of the line of stroke than on the inner or trunk side. The
necessary supply area is then obtained by making the ends of the passages perpen-
dicularly to the line of stroke wider than on the inner sides where the widths
correspond to the widths of the ports in the trunk. The divisions between the supply
passages in the stationary plates must be small compared with the length of the trunk
ports in order that when all the passages are opened, the trunk ports may not be
closed in passing over them.
Manah 1806

page_text: An Improvement in Governing Gear for Steam Engines.
I, CHARLES HORACE BENTON, Engineer, of 46 St. Michael's Road, Headingley,
Leeds, 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 :-
My.invention relates to that form of steam engine in which the steam is supplied
to the cylinder through a hollow trunk attached to the piston. In these engines a
trunk works through a gland into the steam chest and has ports in its circumference.
The end of the trunk in the steam chest is close 1. The ports in the trunk therefore
form the only means of communication between the steam chest and the cylinder.
At the beginning of the stroke of the engine, the steam flows into the cylinder
and continues until the ports in the trunk pass through the gland. The steam
is then cut off, and the piston is driven to the end of the stroke by the
expansion of the steam. The distribution of the steam otherwise than herein described
is effected by a slide valve working within the hollow trunk. My present invention
is intended to provide an equilibrium valve which will effect this cut-off and which
can be moved with a minimum of friction.
In the accompanying drawing I have illustrated a governing gear embodying my
present improvement:
Fig. 1 is a section through the steam chest of a vertical steam engine showing a
plan view of the cut-off gear.
Fig. 2 is a section through A B of Fig. 1.
Fig. 3 is a side elevation from the side.A of Fig. 1.
Similar parts in the three figures have similar numbers.
1 is the moving trunk. 2 are ports in the trunk opposite to each other and made
at such a distance beyond the gland 3, when the piston is at the beginning of the stroke,
as will give the latest cut-off desired. I then fix plates 4 opposite each other in the
steam chest against the sides of which slide the sides of the trunk. In the drawing
these plates are shown as the opposite flat sides of a single sleeve. These fixed.
plates are cut through by passages 5 which correspond in width on the inner side
to the ports in the trunk. Their aggregate length extends over such proportion of
"the stroke as will give the limits of expansion required. On the outsides of the
stationary plates I arrange movable plates 6, which will close the passages in the
stationary plates and give an earlier or later cut-off as the passages closed by
the movable plates are further from, or nearer to, the engine cylinder. These opposite
movable plates are rigidly connected by bars or stays 7 outside the trunk. When
the pressure within the trunk is less than the pressure in the steam chest, the
pressure upon one movable plate, which would press it up to the face of the fixed
plate, is conveyed by these bars to the other movable plate. As the pressures upon
the movable plates are in opposite directions they neutralise each other through the
bars and leave the plates in equilibrium. In order that a slight movement of the
movable cut-off plates may make a considerable difference in the degree of expansion,
I make the divisions between the passages in the fixed plates radiate from a
common centre. The movable plates are then swung from centres 8 so that they can
be moved by a lever 9 outside the steam chest, connected with an ordinary centrifugal
or other governor.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim'is:
In a governing gear in which the steam is cut off by a trunk with opposite ports

page_text: moving over passages into the steam chest, the employment of rigidly connected
plates to open or close these passages, substantially as described herein, with reference
to the accompanying drawing.
Dated this 16th day of December 1896
CHARLES HORACE BENTON.