Year: 1888

page_text: I, CHARLES HORACE BENTON, Engineer, of 2 Victoria Mansions, Victoria Street,
London, S.W., 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 one or more 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 begining 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 working within the hollow trunk. This valve may be worked by
means of the valve gear described in letters patent granted to me, No. 5880, the
30th April, 1886.
I utilize this cut-off as a means of governing the speed of the engine in the
following manner: I make a port in the trunk at such a distance beyond the gland
when the piston is at the begining of the stroke as will give the latest cut-off desired.
1 then fix a plate in the steam chest against the side of which slides the side of the
trunk in which the port is cut. This fixed plate is cut through by several passages
which correspond in width on the inner side to the port in the trunk. The passages
are arranged in the line of stroke of the engine and their aggregate length extends
over such proportion of the stroke as will give the limits of expansion required. On
the outside of the stationary plate I arrange a movable plate under the control of the
governor of the engine or to be moved by hand which will close the passages in the
stationary plate, giving an earlier or later cut-off as the passages closed by the movable
plate are farther from or nearer to the engine cylinder. In order that a slight
movement of this movable cut-off plate may make a considerable difference in the
degree of expansion I make the divisions between the passages radiate from a common
D

page_text: 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 perpendicularly to the line of stroke
wider than on the inner side where the width corresponds to the width of the port
in the trunk. The divisions between the supply passages in the stationary plate
must be small compared with the length of the trunk port in order that when all
tho passages are opened the trunk port may not be closed in passing over them
If the movable plate is on the point of closing one of the passages the steam is
throttled and as far as that passage is concerned the action is the same as that of an
ordinary throttle valve.
Dated this 29th day of March 1888.

page_text: COMPLETE SPECIFICATION.
An Improvement in Governing Gear for Steam Engines.
I, CHARLES HORACE BENTON, Engineer, of Victoria Mansions, Victoria Street,
London, S.W., 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 one or more 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 begining 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 stroko by the expansion
of the steam-The distribution of the steam otherwise than here described is effected
by a slide valve working within the hollow trunk or piston-This valve may be
worked by means of the valve gear described in letters patent granted to me
No. 5880, the 30th April, 1886.
I utilize this cut-off as a means of governing the speed of the engine in the
following manner: I make a poit in the trunk at such a distance beyond the gland
when the piston is at the begining of the stroke as will give the latest cut-off
desired I then fix a block in the steam chest against the side of which slides the
side of the trunk in which the port is cut-This fixed block is cut through by several
passages which correspond in width on the inner side to the port in the trunk-The
passages are arranged in the line of stroke of the engine and their aggregate length
extends over such proportion of the stroke as will give the limits of expansion
required On the outside of the fixed block I arrango a movable plate under the
control of the governor of the engine or to be moved by hand which will close the
passages in the fixed block, giving an earlier or later cut-off as the passages closed
are farther from or nearer to the engine cylinder-These passages do not go straight
through the block but change their form and direction as hereinafter described.
DESCRIPTION OF DRAWING.
Figure 1 represents a plan view of the governing gear as placed in the steam
cbest of a vertical engine-Figure 2 is a section through A B of figure 1-Figure 3
is an elevation from the side A in figure 1. Similar parts in the three figures have
similar numbers-1 is the steam chest-2 is the trunk or prolongation of the piston―
3 is the block or plate containing the passages which are closed by the movable
plate 4 The plate 4 is moved by the link 5 attached to the spindle 6-The spindle 6
hva Governor
nasses through the steam chest and may he moved by hand or

page_text: stroke-8 is the port in the trunk to which correspond on the inner side the inner ends
of the steam passages 9, 10, 11, 12-As the valve 13 opens the port 8 the steam enters
the cylinder as shown by the arrows-As the piston makes its stroke the steam
enters successively through the passages 9, 10, 11, 12-The upper end of the trunk
is always closed by the valve-If the outer ends of those passages are closed by the
movable plate 4 steain will be cut off as the port 8 leaves the previous unclosed
passage-If the passages through the block 3 were parallel and of the same form
throughout as the port 8 the plate 4 would have to move through the same distance
as the length of the stroke during the limits of expansion-As the plato 4 must be
botween the cylinder head 14 and the port 8 at the begining of the stroke, parallo!
passages in the block would necessitate the port 8 to be farther from the piston and
so to increase the clearance in the trunk 2-[ am aware that a similar construction
with parallel passages has been made heretofore but I avoid the difficulties encountered
by such construction by altering the form and direction of the passages as thoy pass
through the block-In the gear as shown, the form and direction of the passages is
altored in three directions, lengthways to lessen the governor movement without
lessening the supply area for steam, the passages are turned upwards to lessen tho
clearance, and are made radial to procuro a rotative movement of the plate 4-In
figure 3 the inner ends of the passages are shown by dotted lines.
•
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 :
1. A governing gear in which the steam supply is regulated by a port in the
piston-trunk which supplies the cylinder passing over passages in a block fixed in
the steam chest, said passages having alterations in their form or direction as they
pass through the block and being opened or closed by a movable plate, substantially
as described and shown.
4
2. A governing gear constructed as shown in the annexed drawing.