Improvements in or relating to Automatic Cut Off Gear for Engines.
Year: 1893

page_text: Date of Application; 9th May, 1893-Accepted, 10th June, 1893
COMPLETE SPECIFICATION.
Improvements in or relating to Automatic Cut Off Gear for Engines.
A communication from THE BRUNO NORDBERG Co., of Milwaukee, Wisconsin,
United States of America.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
Chartered Patent Agent, 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 automatic cut off engines, and its main objects are to
produce a simple, durable, efficient valve gear for operating the steam admission
valves, to prevent noise, to permit of increasing the speed of this class of engines,
to increase the range of cut off from zero to full stroke, to prevent wear or breaking
of the engaging parts of the trip steels from interfering with the operation of the
valves and thereby stopping the engine, to provide for immersing the trip steels
in oil and thereby to prevent or diminish the wear thereof, to automatically relieve
the cylinder of strain due to the presence of water therein, or to pressure in excess
of the steam pressure arising from any other cause within the cylinder, and
thereby avoid the bursting of or injury to the cylinder, to provide for and
facilitate the removal of the exhaust valves and their seats and to prevent leakage
from the cylinder around them, and generally to improve the valves and valve
gear for this class of engines.
In the accompanying drawings like letters designate the same parts in the several
figures.
Figure 1 is a vertical cross section of an engine provided with these improved
valves and valve gear, the valve gear at one end of the cylinder being shown
in side elevation and in the position assumed by it just before opening the admission
valve;
Fig. 2 is a similar view showing the admission valve gear in the position occupied
by it just after the release and closing of the valve; and
Fig. 3 is a side elevation of a portion of the cylinder showing the valve gear
at one end thereof.
For the purpose of illustration the valve gear is shown and will be described as
at one end of the cylinder only, it being obvious that the valves and their connections
are duplicated at both ends of the cylinder.
A is the cylinder, which may be of the usual or any suitable construction for the
class of engines above mentioned. B is a double beat poppet steam admission valve,
and a double annular valve seat having a closed disc-shaped bottom 6' and fitted
to and loosely inserted in an opening in the cylinder. The stem 62 of said valve
passing through a stuffing box in the steam chest or valve chamber cover, is
attached at its outer end to a head or piston c fitted and arranged to work within a
cage or cylinder C. A. spring c¹ interposed between the upper or outer end of the
head and an inverted cone-shaped follower c² is provided for closing the valve and
holding it normally upon its seat, and a screw c threaded in the upper end of the
cap of cage C bears at its end in the apex of the conical follower c² and serves to
regulate the tension of the spring c'. The lower end of the cylinder C is closed
and constitutes a dash-pot for the lower end of the head c which is fitted therein
and serves to check the valve B as it descends upon its seat.
D represents the lay shaft which is geared or otherwise connected with the crank
shaft of the engine so as to revolve synchronously therewith. It is supported
parallel with the cylinder in brackets a projecting therefrom and is provided
opposite each end of the cylinder with an eccentric d with which is conuected by a
strap or box e an arm E. This arm E which for the purpose of symmetry and

page_text: strength is preferably made heart-shaped, is linked by one arm of a bell-crank
lever F to the bracket a or other suitable fixed support, at f. G is a lever pivotted
at one end on a cross pin c to the head c and connected at the opposite end by a
rod g with the arm E at e¹. H is a bell crank lever, the shorter arm of which is
forked and pivotted as shown in Figure 2 at h to and between ears on a bracket a¹
attached to and projecting from the steam chest or valve chamber. The longer
arm of said lever H is connected by a rod h¹ with the other or free arm of the bell
crank lever F at f. Between its forked arms said lever H is formed with an oil
well and is provided therein with a cross bar 8 which constitutes one of the trip
blocks or steels. I is a bell crank lever having its shorter arm forked and pivotted
to opposite sides of the lever G at i. To the end of its shorter arm is attached the
other trip block or steel ¹ while its longer arm is connected by a rod j with a
crank on rock shaft J parallel with the cylinder and connected with the governor
(not shown). When the trip steels h³ and are in engagement, the pivot
connection of lever I with lever G is in line with the pivot connections of lever H
with the bracket a' and the engaging faces of said trip steels are formed to the
segment of a cylinder with its axis coincident with the centres of pivots h and ¿¹
so that the lever G in lifting the valve B from its seat, will be supported upon
said trip steels, and while they are in engagement the fulcrums of levers G H and I
will be coincident or in a line passing through the pivots h and ¹.
The cylinder A is formed at each end on the opposite side from the steam chest
or admission valve chamber, with an exhaust valve chamber, in which is fitted and
held a double valve seat k formed with a perforated externally threaded stem k¹
through which the stem 2 of valve K passes.
12
The
L is an internally threaded sleeve, formed at one end with a flange / and fitted
into and opening in the exhaust valve chamber cover, as shown in Figure 1. It is
extended outside of said cover, and constitutes a stuffing box for the valve stem k
passing through it, and is squared on the outside or provided with means by which
it may be turned in the valve chamber cover and on the threaded stem of the
valve seat which is thereby forced tightly against its bearing at k³ in the valve
chamber. The same operation forces the flange / on the stuffing box tightly against
the bearing to which it is fitted on the inside of the valve chamber cover.
stuffing box L is screw threaded at its outer end and is provided with a gland
inserted therein, and a screw cap by which said gland is adjusted and held in
place and the packing is compressed. By this construction and arrangement of the
exhaust valve chamber, seat and stuffing box, the valve and its seat may be readily
removed together and when worn or broken may be easily repaired or replaced and
leakage of steam from the cylinder into the valve chamber between the valve seat
and chamber at kaud from the valve chamber into the atmosphere between the
stuffing box and valve chamber cover at k* is prevented the joints at k³ and k* being
nicely fitted and tightly closed by turning the sleeve or stuffing box L upon the
screw threaded stem as above mentioned. Leakage of steam from the cylinder
into the valve chamber between the stem k' on the valve seat and the valve stem k²
thence between the stuffing box L and said valve seat stem k¹ also the leakage of
steam from the valve chamber into the atmosphere between the valve seat stem k¹
and the stuffing box are prevented by the packing in said stuffing box.
Opposite each exhaust valve the lay shaft D is provided with a cam M as shown
in Figure and a lever N fulcrummed upon a cross rod n in bracket a is provided
at its upper end with a friction roller in the path of cam M and is connected at its
lower end by a rod n' with a lever O which is fulcrummed at o to a bracket a
formed with or attached to the exhaust valve chamber cover. The opposite end of
lever O is pivotally connected with a head k secured to the outer or lower end of
the valve stem and supported and guided in a sleeve a on the bracket a³. The
head is extended below and formed into a spring case in which is inserted a
spring bearing at its upper end against a disc ' attached as shown in Figure 3
to the sleeve a. At its lower end said spring bears upon a conical follower k
resting upon an adjusting screw k³ threaded in the lower end of said spring case so

page_text: as to afford means of adjusting the tension of said spring. The spring ke acting in
opposition to the lever Ŏ in opening the valve, serves to close said valve and hold
it normally upon its seat. The connecting rods ghj and n¹ have right and left
screw threaded connections at opposite ends with their heads, whereby they may be
lengthened or shortened in the usual manner, for the purpose of adjusting the
movement of the valve gear and valves as desired.
The cam M by which the exhaust valve is opened, is made of two parts, one of
which is fixed upon the lay shaft D and the other loosely mounted thereon and
adjustably attached by a bolt to the fixed part, whereby the said cam may be
readily and accurately adjusted so as to properly regulate the time of the opening
and closing of the exhaust valve.
This improved valve gear and valves operates as follows; The lay shaft D
rotating with the crank shaft in the direction indicated by the arrow, causes the
pivot connection e¹ between arm E and connecting rod g to describe an approximately
semi-circular figure, as indicated by dotted lines in Figures 1 and 2. The admission
valve and its operating connections are shown in Figure 1 in the position which
they occupy just before the valve is opened, the trip steel h³ and being in engage-
ment and affording a fulcrum for the valve opening lever G at a point between its
ends in line with the fulcrum of lever H. As the pivot connection e' at the lower
end of connecting rod g moves in the direction indicated by the arrow in Figures 1
and 2 from 1 towards 2, in the descending curve of the semi-circular figure, lever G
is turned on its pivot connection with lever I supported by the trip steels, and its
inner end is raised, thereby lifting the valve B from its seat; at the same time the
inner end of bell crank lever F descending turns lever H on its fulcrum h thereby
carrying the trip steel ³ towards the valve stem out of engagement with the trip
steel on lever I, which is substantially fixed in position with relation thereto.
The point in the movement of the valve gear where the trip steel h³ clears the
trip steel i will vary according to the relative position of the trip steel ¹ which is con-
trolled by its governor connections, an increase of speed in the engine tending to carry
the trip steel to the right and thereby causing an earlier cut off, and a decrease
in speed tending to carry said trip steel to the left, thereby causing a later cut off.
In this connection it should be stated that any wear on the engaging edges of
the trip steels or the accidental breaking of either steel, will be compensated for
by the governor without interfering with the operation of the engine, because any
wearing away or breaking of the steels which would result in less engagement or
lap thereof, producing an earlier cut off and consequently a decrease in the speed
of the engine, would operate through the governor by moving the trip steel i to
the left to increase the lap or engagement of the trip steels and thereby produce a
later cut off and increase the speed of the engine.
As soon as the trip steel ³ is carried out of engagement with the trip steel ¿¹
lever G being unsupported between its ends is allowed to drop at its inner end, and
the spring c¹ instantly closes the valve B. Just after the closing of the valve its
actuating connections occupy approximately the position in which they are shown
in Figure 2. As the pivot connection e' at the lower end of rod 9 describes the
ascending curve of the semi-circular figure from 2 to 3 the outer end of lever G is
correspondingly raised. While the lower end of connecting rod g passes from 3 to 1
describing the approximately straight side of the semi-circular figure, the outer end
of the valve opening lever G remains quiescent; at the same time, the outer end of
lever H is raised by the bell crank lever F, the trip steel ³ is carried to the right
underneath the trip steel and the admission valve operating gear again assumes
the position in which it is shown in Figure 1. While the lower end of said con-
necting rod is describing the descending portion of the curve from 1 to 2 the outer
end of lever G is lowered to the full extent of its movement, and the valve B is
quickly opened to the fullest extent.
It will be observed that the operation of valve B is effected by a very limited
lateral movement of the lever G and that the engagement and disengagement of
the trip steels is effected by a movement thereof transversely to the direction of

page_text: the movement of lever G. In this way a wide range of engagement of the trip
steels is produced without bringing them abruptly or violently together, and noise
and wear are thus avoided.
The cam M operating through the lever N connecting rod n¹ and lever O upor
the head on the lower end of the stem opens the exhaust valve K at the
proper time, holding it open the desired interval of time according to the adjustment
of said cam.
When the cam M passes out of engagement with the friction roller
in the upper end of lever N said valve is closed by the spring kº. When the
exhaust valve or its seat is broken or becomes worn, or for any other reason
requires inspection, they can be readily removed with the cover of the valve
chamber in which they are placed. In case leakage should occur between the valve
seat and chamber or between the stuffing box and valve chamber cover, it can be
stopped without interrupting the operation of the engine by simply turning the
sleeve or stuffing box L so as to force the valve seat k and the flange on said
stuffing box in opposite directions tightly against their bearings k³ and k. Should
the engine be started while water is in the cylinder which would subject it to
internal pressure in excess of the steam pressure, the admission valve B with its
seat b will be lifted automatically, thereby instantly relieving the cylinder of a
pressure and strain which might otherwise burst or injure it." While the train of
connections between the valve B and the lay shaft D are constant and unbroken
they are such that said valve is free at all times to yield outwardly against the
tension of spring c¹ to au excessive pressure within the cylinder. By the con-
struction and arrangement of the valve gear, and particularly of the trip steels and
their connections together with the oil well herein before described, I am enabled to
immerse and run the trip steels in oil, thereby preventing noise and greatly
reducing the wear of said steels.
Various changes both in the construction and arrangement of parts herein-
before described may be made within the spirit and intended scope of this
invention.
Having now particularly described and ascertained the nature of the said
invention as communicated to me by my foreign correspondents, and in what
manner the same is to be performed, I declare that what I claim is :-
1. The combination with an engine valve of a lever connected therewith for
opening the same and provided with a movable fulcrum support which is capable of
being displaced or withdrawn to allow the valve to be closed, substantially as and
for the purposes set forth.
2. The combination with an engine valve of a lever connected therewith and
having a connection with the crank shaft for opening said valve and a shifting
fulcrum support arranged to be displaced or disengaged and withdrawn from the
support of said lever to permit of the closing of said valve substantially as and
for the purposes set forth.
3. The combination with an engine valve of a lever connected therewith and
having a connection with the crank shaft for opening said valve and trip blocks
or steels constituting the fulcrum support for said lever for opening the valve, one
of said blocks or steels having a governor connection, substantially as and for the
purposes set forth.
4. The combination with an engine valve of a lever connected therewith and
having a connection with the crank shaft for opening said valve and trip blocks
or steels constituting the fulcrum support of said lever in opening said valve one of
said blocks or steels having a governor connection and the other a connection with
the crank shaft substantially as and for the purposes set forth.
5. The combination with an engine valve and lay shaft of a lever connected with
said valve an eccentric on said lay shaft an arm connected with said eccentric and
having a link connection with a suitable support and a rod pivotted to and
connecting said arm and lever substantially as and for the purposes set forth.
6. The combination with an engine valve and lay shaft of a lever connected with

page_text: said valve an eccentric on said lay shaft an arm connected with said eccentric and
by a ród pivotted thereto with said lever and having an intermediate link
connection with a suitable support substantially as and for the purposes set forth.
7. The combination with an engine valve and lay shaft connected with the crank
shaft of the engine of a lever connected with said valve an eccentric on the lay
shaft an arm connected at one end with said lever and at the other with said eccentric
a bell crank lever one arm of which links said arm to a suitable support and trip
blocks or steels carried by levers, one of which is fulcrummed to the valve opening
lever and the other to a suitable support the former being connected with the
governor and the latter with said bell crank lever substantially as and for the
purposes set forth.
8. The combination with an engine valve of a lever connected therewith and
having a connection with the crank shaft of the engine for opening said valve and
trip levers formed or provided with trip blocks or steels one fulcrummed to a
suitable support and having a connection with the crank shaft and the other
fulcrummed to the valve opening lever and having a connection with the governor
substantially as and for the purposes set forth.
9. The combination with an engine valve of a lever connected therewith and
having a connection with the crank shaft for opening said valve trip blocks or
steels constituting a fulcrum support for said lever in opening said valve and a
lever carrying one of said blocks or steels and provided with an oil well in which
they are contained substantially as and for the purposes set forth.
10. The combination with an engine valve of a lever connected therewith and
having a connection with the crank shaft for opening said valve and bell crank
levers provided with trip blocks or steels which constitute the fulcrum support of
the valve opening lever, one of said bell crank levers being fulcrummed to the
valve opening lever and having a connection with the governor and the other
provided with an oil well around said trip blocks or steels, being fulcrummed to a
fixed support and connected with the crank shaft substantially as and for the
purposes set forth.
11. The combination with an engine valve of a lever connected therewith
and having a connection with the crank shaft for opening said valve and trip
blocks or steels constituting the fulcrum support of said lever in opening said
valve and having when in engagement concentric pivotal connections one with
said lever and the other with a suitable support substantially as and for the
purposes set forth.
12. The combination with an engine valve of a lever connected at one end there-
with and at the opposite end with the crank shaft for opening said valve and trip
blocks or steels constituting a fulcrum support for said lever in opening said valve
one of said blocks or steels being movable and having a connection with the
crank shaft whereby one block or steel is withdrawn from engagement with the
other and the valve is allowed to close substantially as and for the purposes set
forth.
13. The combination with an engine valve of a lever connected therewith at one
end and at the opposite end with the crank shaft for opening said valve a suitable
device for closing the valve when released, trip blocks or steels constituting the
fulcrum of said lever and having connections one with said lever and the other
with a suitable support said blocks or steels being movable into and out of range
with each other transversely to the movement of said lever in opening and closing
said valve, one block or steel having a connection with the crank shaft and the
other with the governor whereby more or less engagement of said blocks or steels
is produced and they are disengaged sooner or later to permit the closing of
said valve according to the speed of the engine, substantially as and for the
purposes set forth.
14. The combination in an engine of a poppet admission valve, valve operating
gear constructed and arranged to permit said valve to open outwardly a valve seat

page_text: loosely seated in an opening into the cylinder and capable of opening outwardly
with said valve, substantially as and for the purposes set forth.
15. The combination in an engine of an outwardly opening double beat poppet
admission valve, valve operating gear constructed and arranged to permit said
valve to open and a double valve seat having a closed end seated in an opening into
the cylinder and capable of opening outwardly with the valve, substantially as and
for the purposes set forth.
16. The combination in an engine of a poppet admission valve a lever con-
nected at one end with the valve stem and at the opposite end with the lay
shaft and trip blocks constituting a fulcrum support at an intermediate point in
said lever for opening said valve, one of said blocks being movable into and out
of range with the other and having a connection with the lay shaft whereby the
fulcrum support of said lever is withdrawn at the desired point in the stroke of
the piston and the valve is permitted to close, substantially as and for the purposes
set forth.
17. The combination in an engine of a poppet admission valve a lever connected
at one end with the valve stem and at the other end with the lay shaft and trip
blocks constituting a fulcrum support for said lever for opening said valve one of
said blocks being movably connected with said lever and the other with a fixed
support and one having a connection with the lay shaft and the other with the
governor whereby the fulcrum support of said lever is withdrawn at a variable
point in the stroke of the piston according to the speed of the engine substantially
as and for the purposes set forth.
18. The combination with an engine valve of a lever connected therewith and
arranged to open the same, trip blocks constituting a fulcrum support for said lever
in opening said valve one being movable transversely to the movement of said lever
into and out of range with the other, and an oil well in which said trip blocks
operate substantially as and for the purposes set forth.
19. In an- engine the combination with an exhaust valve and chamber of a
removable valve seat fitted in an opening into the cylinder and provided with a
threaded stem and an internally threaded flanged sleeve fitted in an opening in the
valve chamber cover and screwed upon said stem substantially as and for the
purposes set forth.
20. In an engine the combination with the cylinder exhaust valve and valve
chamber of a valve seat fitted to an opening into the cylinder and provided with a
hollow threaded stem through which the valve stem passes, and an internally
threaded flanged sleeve fitted in an opening in the valve chamber cover and screwed
upon said threaded stem, said sleeve being extended outside of the valve chamber
and provided with means for turning the same, substantially as and for the purposes
set forth.
21. In an engine the combination with the cylinder exhaust valve and valve
chamber of a valve seat fitted to and opening into the cylinder and provided with
an externally threaded hollow stem through which the valve stem passes, and an
internally threaded flanged sleeve screwed upon the valve seat stem and fitted in an
opening in the valve chamber cover with its flange fitted to and bearing against
the inside of said cover said sleeve projecting outside of the valve chamber and
being formed with a stuffing box for the valve stem substantially as and for the
purposes set forth.
22. In an automatic cut off engine the combination of trip blocks or steels
and an oil well in which they are contained substantially as and for the purposes
set forth.
23. In an engine the combination with a valve and lay shaft provided with a
crank or eccentric of a valve opening lever connected with said valve and an arm
connected at or near one end by a box or strap with said crank or eccentric and at
or near the other end with said valve opening lever and having an intermediate
suspended link connection with a fixed support at a point approximately in line

page_text: with the crank or eccentric and lever connections of said arm, substantially as and
for the purposes set forth.
W. P. THOMPSON & BOULT,
Agents for the Applicant.