Improvements in Crank Shaft Eugines Worked by Expansive Fluid
Year: 1897

page_text: TROYDONALDREIFICATION
Improvements in Crank Shaft Eugines Worked by Expansive Fluid,
I, WILLIAM Sisson, of Quay Street Iron Works, Gloucester, in the County of
Gloucester, Engineer, do hereby declare the nature of this invention to be na
follows:-
This invention has reference to improvements in crank shaft engines worked
by expansive fluid and particularly to improvements in engines of the kind
described in the Specification of former Letters Patent granted to me No. 16459,
dated 24 July 1806, and in which a weight is made to serve the two-fold pur-
pose of a crank balance or counterweight und governor weight.
In comparatively slow running engines of this kind which have a pivoted
weight serving the twofold purpose referred to, it is found that the action of
gravity upon the weight causes it to tend at one part of its revolution to com-
press the spring and at another part to relieve the spring, the effect being that
the action of the governor is rendered uneven and is not entirely dependent upon
the speed of the engine and the corresponding tension of the spring or springs.
Now, according to one part of this invention, form the weight in two portions,
and arrange both those two portions or separate weights on that
side of the crank shaft opposite to the crank and mount one of them on each
of a pair of levers pivoted on gudgeons or pins carried by the crank shaft
or web and so connected to the cocentric sheave that the action of gravity
upon one portion of the weight will always tend to move the sheave in an
opposite direction to that in which the other portion tends to move it, but that,
under the action of centrifugal force and the controlling spring or springs both
portions will tend to move the sheave in the same direction.
In one arrangement the weights are mounted on levers whose points of con-
nection with the sheave are, in the one case between the weight and the fulcrum
and in the other case beyond the fulcrum; and in another arrangement, the
weights are attached to the long arms of a pair of oppositely arranged bell crank
levers, adapted to turn in opposite directions under the action of centrifugal
force, the short arms of the levers projecting towards each other and being suit-
ably connected to the eccentric sheave; for example one lever is directly con-
nected by a pin and the other by a pin carrying a block working in a slot in the
sheave so as to allow of the required movement. To ensure the correct move-
ment of the sheave across the shaft, it may be linked to the crank web.
It has become recognized that to obtain the best results with engines subject
to greatly varying loads, the governing should be effected by varying the point
of cut off by means of an automatic expansion governor when the engine is
running with heavy loads, say from full load to three quarter load or probably
even less and that, when it is running with light loads, say from
one quarter load or probably even more down to no load, the govern-
ing should be effected by throttling the steam supply.
be done. For this purpose,
of this invention is to enable this
to
An object

page_text: I connect the weight or weights of an automatic expansion governor
with the throttle valve of the engine in such a manner as to allow the governor
to vary the point of cut off when the slide valve is working so as to give a late
cut off without causing the steam supply to be throttled, but that, when the
slide valve is working so as to give an early cut off, the throttle valve will be
caused to reduce the supply of steam, the arrangement being such that the
steam supply shall commence to be throttled and may be entirely shut off by
the throttle valve before the slide valve attains the position of earliest cut off.
According to one arrangement I connect the weights of a governor constructed as
The
herein before described with the throttle valve lever in the following manner.
crank web to which the weights are pivoted is made hollow and within it is
arrouged a rod that has pivoted to its outer end a bridge piece whose ends are
connected by rods or links with the weight levers or bell cranks and between
which and an abutment or abutments on the crank web, the spring or springs
is or are arranged. That part of the crank shaft adjacent to the hollow web is
also made hollow and into it extends a rod, the outer end of which is provided
with collars and is connected with the forked end of the throttle valve lever,
whilst the inner end of this rod is connected with the rod located in the crank
web and thus to the weights by means of a bell crank lever pivoted within the
hollow portion of the crank. The bell crank lever is preferably provided at the
ends of its arms with antifriction rollers that take into slots in the enlargel
inner ends of the respective rods. To enable such a governor to be adjusted to
suit varying requirements whilst in action, I provide between the end of the
crank shaft and a collar on the rod that extends into it, a spring the action of
which can be regulated whilst the governor is in motion by means of an externally
screwed adjusting boss or wheel working in a floating wheel abutting against
the end of the shaft.
.
In order to prevent the throttling of the steam supply being varied in accor-
dance with the variation of the point of cut off when running with a heavy load,
I employ a hollow cylindrical throttle valve, the lateral ports through it and its
concentric casing being made of considerably greater total area than that of the
steam supply pipe. The valve is preferably balanced and the forked lever con-
necting it with the governor is adjustably connected to its spindle, so that the
point at which throttling will commence can be varied.
In governors in which the weight slides on a crank web I connect the weight
with the bell crank lever in any convenient way, for instance, by means of a rod
one end of which is screwed into the weight and the other end or an intermediate
portion is formed with a slot engaging with the antifriction roller of the bell
crank lever pivoted in the crank shaft.
Improvements in Crank Shaft Engines Worked by Expansive Fluid.
I, WILLIAM SISSON, of Quay Street Iron Works, Gloucester, in the County of
Gloucester, Engineer, do hereby declare the nature of this invention and in
what manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement:-
This invention has reference to improvements in crank shaft engines worked
by expansive fluid and particularly to improvements in engines of the kind

page_text: described in the Specification of former Letters Patent granted to me No. 16459,
dated 24 July 1896, and in which a weight is made to serve the two-fold pur-
pose of a crank balance or counterweight and governor weight.
In comparatively slow running engines of this kind which have a pivoted
weight serving the twofold purpose referred to, it is found that the action of
gravity upon the weight causes it to tend, at one part of its revolution, to com-
press the spring and, at another part, to relieve the spring, the effect being that
the action of the governor is rendered uneven and is not entirely dependent upon
the speed of the engine and the corresponding tension of the spring or springs.
Now, according to one part of this invention, I form the weight in two portions,
and arrange both these two portions or separate weights on that
side of the crank shaft opposite to the crank and mount one of them on each
of a pair of levers that are pivoted on gudgeons or pins carried by the crank shaft
or web and that are so connected to the eccentric sheave that the action of gravity
upon one portion of the weight will always tend to move the sheave in an
opposite direction to that in which the other portion tends to move it, but that,
under the action of centrifugal force and the controlling spring or springs, both
portions will tend to move the sheave in the same direction.
It has become recognized that to obtain the best results with engines subject
to greatly varying loads, the governing should be effected by varying the point
of out off by means of an automatic expansion governor when the engine is
running with heavy loads, say from full load to three quarter load, or probably
even less and that, when it is running with light loads, say from
one quarter load or probably even more down to no load, the govern-
ing should be effected by throttling the steam supply. An object
of this invention is to enable this to be done. For this purpose,
I connect the weight or weights of an automatic expansion governor
with the throttle valve of the engine in such a manner as to allow the governor
to vary the point of cut off when the slide valve is working so as to give a late
cut off without causing the steam supply to be throttled, but that, when tho
slide valve is working so as to give an early cut off, the throttle valve will be
caused to reduce the supply of steam, the arrangement being such that the
steam supply shall commence to be throttled and may be entirely shut off by
the throttle valve before the slide valve attain, the position of earliest cut off.
Referring to the accompanying illustrative drawings
Fig. 1 is a sectional end elevation of the crank shaft of an engine fitted with
an automatic expansion governor according to this invention; and
Fig. 2 is a sectional front elevation of the same.
Fig. 3 is a plan showing the general arrangement of the gear connecting the
weights of the governor to the throttle valve lever; and
Figs. 3 and 4 are detail views hereinafter referred to.
1 is the crank shaft, 2 the crank pin and 3 the crank web, in one with, or
attached to which, is a frame 3. 4, 4* are the governor weights both of which
are arranged on that side of the shaft opposite to the crank; the weights 4, 4"
also serve to partly counterbalance the crank web and pin. The weights 4, 4
are mounted on levers 5, 5* that are pivoted on pins 6, 6 carried by the frame 3*
and are respectively connected to the eccentric sheave 7 by pins 8 and 8, the
pin 8 being between the weight 4 and its fulcrum pin 6, whilst the pin 8ª is
beyond the fulcrum pin 6* of the lever 5. The levers 5 and 5* are formed with
arms 5 which extend towards each other and are connected by links 9, 9 to a
bridge piece 10, the ends of which carry trunnion nuts 10 into which screw
rods 11 that extend through guide holes in abutments 11* formed on the frame 3*;
between the said abutments and adjustable nuts on the said rods 11 are arranged
compression springs 12 that tend to keep the weights in their inward positions.
The links 9, 9 may, if convenient, lie in grooves or recesses formed in the edges
of the crank web 3, the central portion of which is made hollow and within it is
arranged a rod 13 the outer end of which is pivoted to the bridge piece 10. That
part of the crank shaft adjacent to the hollow web is also made hollow as shown

page_text: at 1 and into it extends a rod 14, the outer end of which is provided with a
grooved sleeve 15 as shown in Figs. 3 and 4 with which the forked end of the
throttle valve lever 16 engages. The inner end of the rod 14 is connected with
the rod 13 by means of a bell crank lever 17 that is pivoted within the hollow
portion of the crank and is preferably provided, at the ends of its arms, with
antifriction rollers 17" that take into slots in the enlarged inner ends of the
respective rods.
It will be noted that the action of gravity upon the weights 4, 4* tends to turn
their levers 5, 5" in the same direction, and consequently the one weight tends
to move the sheave 7 in the opposite direction to that in which the other weight
tends to move it; but the action of centrifugal force will tend to turn the
levers 5, 5 in opposite directions and consequently they will assist each other
in moving the sheave across the shaft. In order to prevent the throttling of the
steam supply being varied in accordance with the variation of the point of cut off
when running with a heavy load, I employ such a balanced throttle valve as
the hollow oylindrical valve 18 shown in horizontal section in Fig. 3. The
lateral ports 18 through the throttle valve and its concentric casing 18b are
made of considerably greater total area than that of the steam supply pipe 18.
The valve is preferably balanced and the forked lever 16 is slotted so that the
point of connection therewith of the link 19 that couples it to an arm on the
valve spindle can be adjusted and the point at which throttling will commence
thus altered. To enable the governor to be adjusted to suit varying requirements
whilst in action, I provide in the manner illustrated in Fig. 4, between the end
of the crank shaft 1 and a fixed collar or nut 20 on the rod 14, a spring 21
which supplements the resistance offered by the springs 12 to the outward move-
ment of the weights 4, 4", and assists the said springs 12 in returning the weights
to their inward positions. The action of the spring 21 can be regulated, whilst
the governor is in motion, by means of an externally screwed adjusting boss
or wheel 22 working in a floating wheel 23 abutting against the end of the shaft.
When it is desired to vary the compression of the apring 21 the floating wheel 23
and sleeve 19 can be brought to rest either by hand or by means of a brake block
adapted to be put in contact with the wheel 23 by a lever 24; the wheel 22 can
then be screwed more or less in or out of the wheel 23.
In governors in which the weight slides on a crank web I connect the weight
with the hell crank lever 17 in any convenient way, for instance, by means of a
rod one end of which is screwed into the weight and the other end or an inter-
mediate portion is formed with a slot engaging with the antifriction roller of
the bell crank lever pivoted in the crank shaft.
Fig. 5 is a sectional end elevation;
Fig. 6 a longitudinal section of a modified arrangement; and Fig. 7 is a plan
of certain parts thereof.
In this case the weights 4, 4" are attached to the long arms of a pair of
oppositely arranged bell orank levers 5, 5* adapted to turn in opposite directions
under the action of centrifugal force, the short arms of the levers projecting
towards each other and being suitably connected to the eccentric sheave; in the
example illustrated the lever is directly connected by a pin 8 and the lever 5*
by a pin 8 carrying a block 25 working in a slot 26 in the sheave 7 Bo as to
allow of the required movement. To ensure the correct movement of the sheave 7
across the shaft 1 it may be coupled by a link 27 to the crank web 3.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is:-
-
1. A crank shaft engine in which both of two shaft governor weights are pivoted
on that side of the crank shaft that is opposite to the crank and are so connected
to the eccentric sheave that the action of gravity upon the one weight will tend
to move the sheave in an opposite direction to that in which the action of gravity

page_text: on the other weight tends to move it, but that, under the action of centrifugal
force and the controlling spring or springs, both weights will tend to move tho
sheave in the same direction, substantially as described.
2. A crank shaft engine of the kind specified in Claim 1, in which the governor
weights are mounted on levers whose points of connection with the sheave arc,
in the one case, between the weight and the fulcrum and, in the other case, beyond
the fulcrum substantially as described with reference to and shown in Figs. 1
and 2 of the accompanying drawings.
3. A crank shaft engine of the kind specified in Claim 1 in which the weights
are attached to the arms of a pair of oppositely arranged bell crank levers, whose
other arms project towards each other and are connected to the eccentric sheave
substantially as described with reference to and shown in Figs. 5, 6 and 7 of the
accompanying drawings.
4. A crank shaft engine having an automatic expansion governor the weights
of which are connected with the throttle valve of the engine in such a manner
as to allow the governor to vary the point of cut off when the slide valve is work-
ing so as to give a late cut off without causing the steam supply to be throttled,
but that, when the slide valve is working so as to give an early cut off, the
throttle valve will be caused to reduce the supply of steam substantially as
described.
5. A crank shaft engine of the kind specified in Claim 1, the governor weight
01 weights of which is or are acted upon by one or more main springs and is or
are connected to a rod that extends axially through the crank shaft from the
governor to beyond the end of the shaft, where it is provided with a supplementary
spring the action of which can be varied whilst the engine is in motion substan-
tially as described.
6. A crank shaft engine having an automatic expansion governor that is cap-
able of adjustment to suit varying requirements constructed arranged and operat-
ing substantially as described with reference to and shown in Figs. 1, 2 and 4, or
modified according to Figs. 5, 6 and 7 of the accompanying drawings.
7. A crank shaft engine having an automatic expansion governor that can be
adjusted to suit varying requirements and whose weight or weights is or are con-
neoted with the throttle valve of the engine constructed, arranged and operating
substantially as described with reference to Figs. 1 to 4 inclusive or modified
according to Figs. 5 to 7 inclusive of the accompanying drawings.
Dated this 7th day of September 1898.