Improvements in Steam Engines.
Year: 1895

page_text: Date of Application, 26th Mar., 1895
Complete Specification Left, 25th Jan., 1896-Accepted, 29th Feb., 1896
Improvements in Steam Engines.
I, HIRAM STEVENS MAXIM, of Baldwyn's Park, Bexley, in the County of Kent,
Mechanical Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates partly to engine governors.
In applying my invention to a small engine I provide the cylinder with an
ordinary slide valve operated by an excentric which is connected with a governor
that controls the speed of the engine by moving the said excentric across the crank
shaft.
The governor is a weight carried by the fly wheel and movable radially therein
and arranged in combination with a spring which resists the tendency of the weight
to move away from the axis of the fly wheel under the influence of centrifugal
force. The weight is connected by an arm or bar to a disc or plate which is fitted
on a small shaft extending partly through the crank shaft and fitted to turn freely
therein. The said shaft is turned by the weight as the latter changes its position
according to the speed of the engine. The said small shaft has at its inner end a
crank which works in a slot or aperture in an arm extending from the excentric
sheave or block, and as the disc is turned about its axis by the movements of the
weight it moves the excentric more or less across the engine crank shaft thereby
varying the cut-off in accordance with the requirements of the work of the engine.
The said disc or plate has two studs or bolts diametrically opposite each other and
by changing the connection of the said arm of the weight from one to the other of
these studs or bolts the direction of rotation of the crank shaft can be reversed.
The rim of the fly-wheel is formed with a socket into which is screwed or
otherwise secured a rod projecting therefrom towards the axis of the wheel.
The weight is fitted to slide on this rod and has in it a cavity or hollow space
surrounding the rod and in this cavity is placed the spiral spring which resists the
action of the centrifugal force.
This spring has one end seated in a metal cup placed in the socket and its other
end abuts against the inner end of the cavity. The said cup is adjustable by
screwing the rod inward or outward and thereby the tension of the spring can be
regulated as required. The rod is provided with a nut or other device for limiting
the movement of the weight towards the axis.
The engine crank has its arms or webs extended on the side of the shaft
diametrically opposite the crank pin into the form of a quadrant or sector, and the
one adjacent to the excentric has formed in its inner side a recess or cavity for
the reception of the aforesaid small crank the pin of which extends through a
curved slot in the web to an arm of the excentric block or sheave. The said
sheave is formed with along aperture through which the crank shaft extends and
which allows the said sheave to move across the shaft. The aforesaid arm of the
excentric is connected with the engine crank by a pivot pin fixed in the web of
the crank near the axis of the crank pin and projecting in a direction parallel to the
axis of the shaft. The arm of the excentric therefore when actuated by the small
crank turns on this pivot and thereby moves the excentric across the axis of the
shaft along the arc of a circle the centre of which is the aforesaid pivot.
It will be obvious that with the above described method of governing or

page_text: regulating the engine I obtain the advantage that the faster the speed of the
engine the earlier in the stroke will the steam be cut-off, that is to say, the more
quickly will the supply of steam diminish in accordance with the diminished load.
Another advantage is the facility with which the governor weight can be adjusted
on the fly wheel as herein before mentioned to reverse the engine.
In applying my invention to large engines I use piston valves and provide one
set of such valves for the admission and another set for the exhaust. Such valves
permit a freer exhaust of the steam than ordinary flat slide valves used in
connection with my governor and this is an important matter in large engines.
The admission-valves are connected with and controlled by a governor such as that
above described, the exhaust valves being controlled independently and set to give
the desired amount of cushion and release.
The admission-valves and governor are so arranged that the steam is admitted to
the cylinder at full boiler pressure, and cut off almost immediately.
There is an arrangement of double ports for the steam valves which reduces the
amount of travel necessary for the valves. One advantage arising from the use of
the two sets of valves as above described is that the valves are not subjected to
changes of temperature at every stroke of the engine.
Dated this 26th day of March 1895.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.
Improvements in Steam Engines.
I, HIRAM STEVENS MAXIM, formerly of Baldwyn's Park, Bexley, in the
County of Kent, but now of 18 Queen's Gate Place, in the County of Middlesex,
Mechanical Engineer, 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 :-
This invention relates to steam engines and partly to governors for the same.
In applying my invention to a small engine say from one to five horse power
I provide the cylinder with an ordinary slide valve operated by an excentric which is
connected with a governor that controls the speed of the engine by moving the said
excentric across the axis of the crank shaft.
The said invention comprises a centrifugal governor and the combination of the
same with the excentric on the engine crank-shaft. Also the arrangement of the said
excentric so that it will be moved transversely to the axis of the crank-shaft by
and according to the movements of the centrifugal governor due to the variations
in the speed of the engine. The said invention also comprises an improved
arrangement of the slide valve and ports employed in combination with the
aforesaid arrangement of the governor and excentric.
My invention is illustrated in the accompanying drawings in which
Figure 1 is a front elevation and
Figure 2 a side elevation of a steam engine.
Figures 3 and 4 are longitudinal and transverse sectional elevations shewing
the connection of the centrifugal part of the governor with the excentric on the
crank shaft.
Figure 5 is a side elevation shewing the excentric and its adjuncts.
Figure 6 is a side elevation shewing the fly-wheel and centrifugal arrangement.
Figure 7 is a vertical section through the cylinder and slide valve casings c
steam engine.
a
In Figures 3, 4 and 6 the centrifugal governor and parts connected therewith

page_text: are shown in the position they occupy when the said governor is in its outermost
position.
Like letters indicate the same parts throughout the drawings.
A is the bed or foundation plate of the engine; B B are columns supporting the
cylinder C and its adjuncts; D is the crank shaft, D₁ the crank; E is the
excentric for operating the steam supply valve or valves, and F the excentric for
operating the exhaust valve or valves. G is the fly wheel.
The centrifugal governor comprises a weight or pair of weights H carried by
the fly wheel G and free to move radially thereou. Each of these weights is
arranged in combination with a spring H' which resists the tendency of the weight
to move outward or away from the axis of the fly wheel under the influence of
centrifugal force. Each weight H is connected by a rod or bar H2 to a disc
or plate on one end of a small shaft I extending partly through the crank
shaft D as shewn in Figure 3, and fitted to turn freely therein. The said disc is
provided with studs or bolts 12 diametrically opposite each other for the connection
of the rods or bars H2 to the disc. The said small shaft being thus connected
to the governor weights, will be turned thereby about its axis as the weights
move inward or outward on the fly wheel according to the variations of the
speed of the engine. The said shaft I has at its inner end a crank J, the pin J¹
of which works in a slot or aperture E* in an arm E¹ extending from the
excentric sheave or block, so that the disc I' as it is turned about its axis by
the movements of the weights, moves the excentric E more or less across the
axis of the crank shaft D thereby varying the cut off of the slide valves in
accordance with the requirements of the work of the engine
As above stated the said disc or plate I¹ has two studs or bolts 12 diametrically
opposite each other and by simply adjusting or changing the connection of the
rod or bar of each weight H from one to the other of these studs or bolts the
direction of rotation of the crank shaft can be reversed.
According to my invention I provide for the attachment of the sliding.
weights H to the fly wheel as follows-that is to say the rim of the fly wheel
is formed with sockets G₁; into each socket is screwed or otherwise secured a
rod G2 projecting therefrom radially or towards the axis of the wheel. The
weight H is fitted to slide on this rod G2 and has in it a cavity or hollow space
surrounding the rod for the reception of the spiral spring H₁ which resists or
counteracts the action of the centrifugal force.
This spring H' has one end seated in a metal cup G³ placed in the socket G'
and its other end abuts against the inner end of the cavity in the weight as
shewn in Figures 3 and 6. The said cup is adjustable by screwing the rod G³
inward or outward and. thereby the tension of the spring H₁ can be regulated
as required. Moreover the said cup forms a guide for the end of the weight as
the latter slides radially upon the wheel. The rod G2 is provided with a nut G* or
other device for limiting the movement of the weight H inward or towards the
axis of the fly wheel. By arranging the weights H on the fly wheel in this
manuer it will be seen that during the revolution of the fly wheel they offer little
if any surface for the resistance of the atmosphere.
In some
The crank D' has its arms or webs d d' extended and shaped so as to form, on the
side of the shaft D diametrically opposite the crank pin, quadrants or sectors as
shewn at d2 Figure 4, which form counterbalance weights or the crank.
instances only the arm d, that is to say the arm nearest the excentric, may be thus
formed. This arm d has in its inner side a recess or cavity d³ for the reception
of the aforesaid small crank J, the pin J' of which extends from the cavity d³
through a curved slot d in the counterbalance weight or sector d² to the arm E¹
of the excentric block or sheave E as shewn in Figure 3. The said sheave is
formed with a long transverse aperture E2 through which the crank shaft D
extends and which allows the said sheave to move across the shaft D. The
aforesaid arm E¹ of the excentric is connected with the engine crank D' by a
pivot pin fixed in the web of the crank near the axis of the crank pin ai

page_text: shewn at K Figure 3. Therefore when the arm E' is actuated by the small
crank it turns or moves angularly about this pivot and thereby moves the
excentric E transversely to or across the axis of the shaft D along the arc of
a circle the centre of which is the aforesaid pivot K. By connecting the smaller
shaft I with the excentric through the counterbalance weight of the main crank
as shewn I avoid the use of complicated mechanism which would otherwise
have to be used to obviate the necessity of a slot or aperture in the crank shaft.
With the above described method of governing or regulating the speed of
engines I obtain the advantage that the faster the speed the earlier in the stroke
will the steam be cut-off, that is to say the more quickly will the supply of steam
diminish in accordance with the diminished load. Another advantage is the facility
with which the governor weights can be adjusted on the fly wheel as hereinbefore
mentioned to reverse the engine.
By reason of the provision in the excentric block of the aperture or slot through
which the crank shaft extends the latter can be left intact that is to say its strength
will not be impaired by having slots or apertures cut through it to permit the move-
ment of the excentric as in other arrangements heretofore employed or suggested.
Moreover the said excentric can be placed in the most advantageous position on the
crank shaft i.e. in close proximity to the crank.
According to my invention I sometimes use for large engines a double set of
piston valves, that is to say I provide one set of such valves for the admission and
another set for the exhaust of the steam. This arrangement of the valves permits
a more free exhaust of the steam than would be practicable with ordinary slide-
valves used in connection with the above described improved governor, that is to say
it makes the exhaust independent of the cut-off and this is an important matter in
large engines. Moreover another advantage arising from the use of the two sets of
valves is that they are not subject to changes of temperature at each stroke of the
engine.
Referring to Figure 7 C is the cylinder, C' the piston; C² the piston-rod ;
LL are the admission valves and M M the exhaust valves.
The admission-valves L are connected with the excentric which is controlled
by the governor as above described, the exhaust valves M being controlled
independently and set to give the desired amount of cushion and release.
The admission-valves L and the governor are so constructed and arranged that
the steam is admitted to the cylinder at full boiler pressure, and when the engine is
working with a light load the steam will be cut off almost immediately. I provid..
double ports L' for the admission valves L and thereby reduce the length of the
travel necessary for these valves.
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 centrifugal governor consisting of a weight and spring or a pair of weights
and springs arranged substantially as described upon the fly wheel of an engine and
capable of adjustment for moving the excentric block across the shaft and thereby
reversing the said engine.
2. The method of attaching the weights and springs to the fly wheel substantially
as described so that they will offer but little if any surface for the resistance of the
atmosphere.
3. The cup fitted in the socket of the fy wheel for receiving the end of the
spring and guiding the weight and capable of adjustment substantially as and for
the purposes specified.
4. The excentric supported at two points on opposite sides of the crank shaft
and movable across the shaft about one of such points by the action of the governor
at the other point for the purpose specified.
5. The excentric pivotted upon the crank and having its sheave or block slotted
so that without dividing the said shaft or forming any slot or aperture therein the

page_text: said excentric can move transversely to or across the axis of the said crank-shaft
for the purpose specified.
6. The combination or connection of the aforesaid centrifugal governor and
pivotted excentric through the agency of the small central shaft and crank
arranged in combination with the engine crank shaft and crank substantially as
and for the purpose specified.
7. The combination with the governor and excentric of means whereby the
action of the governor is transmitted to the excentric through the counterbalance
weight of the crank substantially as described.
8. A steam engine having its valves and ports constructed as described with
reference to Figure 7 and having its admission valves arranged in combination with
the aforesaid excentric controlled by the centrifugal governor on the fly wheel
substantially as described and for the purpose specified.
Dated this 25th day of January 1896.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.