IMPROVE- MENTS IN APPARATUS FOR AUTOMATICALLY REGULATING THE 'CUT-OFF' FOR STEAM ENGINES
Year: 1879

page_text: LETTERS PATENT to Edward Thomas Hughes, of the Firm of Hughes and Son,
123, Chancery Lane, London, Patent Agents, for the Invention of "IMPROVE-
MENTS IN APPARATUS FOR AUTOMATICALLY REGULATING THE 'CUT-OFF' FOR
STEAM ENGINES." A communication from abroad by Nelson Washington
Twiss, of New Haven, County of New Haven, and State of Connecticut,
United States of America..
Sealed the 23rd September 1879, and dated the 24th March 1879.
PROVISIONAL SPECIFICATION left by the said Edward Thomas Hughes at
the Office of the Commissioners of Patents on the 24th March 1879.
EDWARD THOMAS HUGHES, of the Firm of Hughes and Son, 123, Chancery
Lane, London, Patent Agents. IMPROVEMENTS IN APPARATUS FOR AUTOMATI-
CALLY REGULATING THE 'CUT-OFF' FOR STEAM ENGINES." A communication from
abroad by Nelson Washington Twiss, of New Haven, County of New Haven, and
State of Connecticut, United States of America.
•
This Invention relates to improvements in that class of cut-offs for steam engines
which are adjusted automatically by the action of the governor, and it consists in
the construction as hereinafter described.
On the accompanying Sheet of Drawings,-
Fig. 1 is a side view of a portion of the cylinder showing an outer end view of
the improvements.
Figs. 2 and 3, transverse section through the valve longitudinally through the
steam and exhaust passage.
Figs. 4 and 5, views of the gearing to illustrate the operation.
Fig. 6, longitudinal section through the gearing.
In illustrating the Invention the valve and its gearing are shown only as arranged
at one end of the cylinder, it being understood that a like arrangement is made for
the other end. A represents the cylinder, showing an interior view; B, the steam
passage; C, the steam chamber; and D, the exhaust steam way. The valve E is of
a hollow cylindrical form, working upon a correspondingly circular face at the
port a, and attached to a hollow shaft F in axial line therewith, and to which a
constant and regular oscillation is imparted through the lever F¹ on said shaft F by
connection with the eccentric through the rod F2 in the usual manner for operating
Price 6d1

page_text: steam valves. The cylindrical valve E has an opening El to the steam 'chamber,
through which steam freely passes at all times, and from this cylinder is an opening
d through that portion of the valve which bears against the valve seat around the
port a, and in the surface of the valve near this bearing portion is a depression e,
and in such relation to the opening d that as the valve is turned, say to the position
indicated in broken lines, Fig. 2, the depression e covers the port a, and opens com-
munication to the passage f for the exhaust.
The oscillation of the valve therefore alternately presents the opening d and the
depression e to the port a, the opening & admitting steam to the cylinder, and the
depression opening for the exhaust, the action being substantially the same as
would be made by a slide valve.
That the valve may be self packing, that portion of the cylinder in which is the
depression e and the opening d is made separate from the cylinder E, and between
the edges of the cylinder and the said active portion springs are introduced, as at h,
more or less in number, the tendency of which is to hold the said active portion to
the seats around the port and exhaust, the steam always holding the valve to those
positions, and thus accomodate the valve to the wear to which it is subjected.
Through the hollow shaft F a second shaft G extends to within the cylinder, and
is there flattened, as in Figs. 2 and 3, to serve as a guide for the independent cut-off
or valve H, which is arranged thereon, as seen in Figs. 2 and 3.
The surface of this valve H is made to correspond to the opposite edges of the
opening d, and so that when brought together, as in Fig. 3, the opening & will be
closed or turned away, as in Fig. 2, and open the steam passage to the cylinder.
On the outer end of this shaft G is fixed a lever L, and to this lever a spring L¹
is applied, the tendency of which is to force the valve H into its closed position,
seen in Fig. 3, and when in that position a shoulder on the lever L strikes the
lever F¹, as seen in Fig. 5, and from that point the lever L is moved by and with
the lever F¹, and would therefore be always closed; to open this valve however, its
movement in the direction indicated by arrows, Figs. 4 and 5, is arrested by a sta-
tionary stop N as the lever Fl is turned forward by the eccentric, the lever L
following it until the lever L strikes the stop N, and this occurs as the piston
approaches the opposite end of the cylinder, and when the valve has reached nearly
its full exhaust position; then the lever F¹ continuing its movement and opening
the exhaust, also turns the valve E so as to open the passage d, and at the extreine
movement of the lever F¹ a dog P on the said lever F1 passes over and engages with
a shoulder m on the lever L, as seen in broken lines, Fig. 5, which connects the lever
L with the lever F'; then as the lever Freverses, it takes with it the lever L and
the valve H, both turning together, and opening the steam passage to the port, as
seen in Fig. 2.
Should this connection of the dog continue throughout the stroke, then the valve
would be open continuously, but it will be readily seen that should the dog be
tripped from its engagement with the lever L at any point during the movement of
the lever F¹, the spring L¹ would immediately act and turn the lever L so as to turn
the valve H and close the steam passage d, and there cut-off the steam.
To automatically make this disengagement during the movement of the lever Fl
to close the valve H, a cam R loose on the shell S, which supports the shafts F, G,
is connected by a rod R! with the governor, and from the dog P an arm P¹ extends
downward in the path of the said cam, and whenever the said arm P' strikes the
cam R, as seen in Fig. 4, the dog will be raised from its engagement with the lever
L, and leave that lever L free to turn by the force of the spring L', as seen in
Fig. 5, and which brings the shoulder on the lever L into engagement with the
lever F on the opposite side, closing the valve H, as seen in Fig. 3, from which
time the two levers F' and L with the valves E and H move together in their closed
condition.
The action of the governor turns the cam R nearer to or further from the point
where the dog P engages the lever L accordingly as the engine runs faster or slower,
and if so slow that tlie cam'is not reached before the completion' of the stroke, then

page_text: the valve will be open through the entire stroke; but as the speed of the engine
increases, the cam R will be moved toward the dog, and trip the dog accordingly.
The time of tripping may be adjusted in the usual manner of adjusting the action
of a governor.
To provide against any interruption of the action of the governor, as by a dis-
connection of the power which drives it, there is a second elevation R¹ on the cam
forward of the cam R, and which when the governor stops will be turned up, as
indicated in broken lines, Fig. 4, so that the arm P¹ will strike it at the extreme
forward movement of the lever F¹, and hold it away from its engagement with the
lever L, in which case the lever L would not be turned until the lever F¹ should
strike the shoulder Z thereon, and consequently the steam passage would not be
opened, as the valve H would be closed from the start and through the entire
movement.
The valve H is preferably arranged with springs between it and its guide or shaft
G, the action of which is to force the valve H radially from the shaft, so as to make
it self-packing or self-adjustable around the opening d.
The form of the valve E need not be that of a cylinder, as shown, as that portion
of the cylinder below the active valve part is only necessary to support that part,
and if that active part be attached directly to the shaft which rotates the valve it
will be evident that the remainder of the cylinder may be dispensed with, it only
being essential that the valve shall be oscillating and substantially concentric with
the axis of the valve H.
While it is desirable that the exhaust should be arranged as a part of the steam
valve, it may be an independent valve, and this Invention is therefore not confined
to making the exhaust valve a part of the steam valve.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edward Thomas Hughes in the Great Seal Patent Office on the
24th September 1879.
EDWARD THOMAS HUGHES, of the Firm of Hughes and Son, Patent Agents,
123, Chancery Lane, London. "IMPROVEMENTS IN APPARATUS FOR AUTOMATI-
CALLY REGULATING THE CUT OFF FOR STEAM ENGINES." A communication from
abroad by Nelson Washington Twiss, of New Haven, County of New Haven, and
State of Connecticut, United States of America.
This Invention relates to improvements in that class of cut-offs for steam engines
which are adjusted automatically by the action of the governor, and it consists
in the construction as hereinafter described, and more particularly recited in the
claims.
On the accompanying Sheet of Drawings,―
Figure 1 is a side view of a portion of the cylinder showing an outer end view of
the improvements.
Figures 2 and 3, transverse section through the valve, longitudinally through the
steam and exhaust passage.
Figures 4 and 5, views of the gearing to illustrate the operation.
Figure 6, longitudinal section through the gearing.
In illustrating the Invention the valve and its gearing are shown only as arranged
at one end of the cylinder, it being understood that a like arrangement is made for
the other end. A represents the cylinder, showing an interior view; B, the steam
passage; C, the steam chamber; and D, the exhaust steam way. The valve E is of
a hollow cylindrical form working upon a correspondingly circular face at the port a
and attached to a hollow shaft F in axial line therewith, and to which a constant
and regular oscillation is imparted through the lever F' on said shaft F by connection
with the eccentric through the rod F2 in the usual manner for operating steam
valves. The cylindrical valve E has an opening E' to the steam chamber through
which steam freely passes at all times, and from this cylinder is an opening & through
that portion of the valve which bears against the valve seat around the port a, and
in the surface of the valve near this bearing portion is a depression e, and in such
relation to the opening d that as the valve is turned say to the position indicated
in broken lines, Figure 2, the depression e covers the port a and opens communication
to the passage f for the exhaust.
The oscillation of the valve therefore alternately presents the opening d and the
depression e to the port a, the opening d admitting steam to the cylinder, and the
depression opening for the exhaust, the action being substantially the same as would
be made by a slide valve.
That the valve may be self-packing, that portion of the cylinder in which is the
depression e and the opening d is made separate from the cylinder E, and between
the edges of the cylinder and the said active portion springs are introduced as at h,
more or less in number, the tendency of which is to hold the said active portion to
the seats around the port and exhaust, the steam always holding the valve to those
positions, and thus accomodate the valve to the wear to which it is subjected.
Through the hollow shaft F a second shaft G extends to within the cylinder, and
is there flattened, as in Figures 2 and 3, to serve as a guide for the independent
cut-off or valve H which is arranged thereon as seen in Figures 2 and 3.
The surface of this valve H is made to correspond to the opposite edges of the
opening d, and so that when brought together, as in Figure 3, the opening d will
be closed or turned away, as in Figure 2, and open the steam passage to the
cylinder.
On the outer end of this shaft G is fixed a lever L, and to this lever a spring L
is applied, the tendency of which is to force the valve H into its closed position,
seen in Figure 3, and when in that position a shoulder 7 on the lever L strikes the

page_text: lever F', as seen in Figure 5, and from that point the lever L is moved by and with
the lever F, and would therefore be always closed. To open this valve however its
movement in the direction indicated by arrows, Figures 4 and 5, is arrested by a
stationary stop N. As the lever F¹ is turned forward by the eccentric, the lever L
following it until the lever L strikes the stop N, and this occurs as the piston
approaches the opposite end of the cylinder, and when the valve has reached nearly
its full exhaust position then the lever F' continuing its movement and opening the
exhaust also turns the valve E so as to open the passage d, and at the extreme
movement of the lever F" a dog P on the said léver F¹ passes over and engages
with a shoulder m on the lever L, as seen in broken lines, Fig. 5, which connects
the lever L with the lever F¹; then as the lever F¹ reverses it takes with it the
lever Land the valve H, both turning together and opening the steam passage to
the port, as seen in Figure 2.
Should this connection of the dog continue throughout the stroke, then the valve
would be open continuously, but it will be readily seen that should the dog be
tripped from its engagement with the lever L at any point during the movement of
the lever F¹, the spring L¹ would immediately act and turn the lever L so as to turn
the valve H and close the steam passage d and there cut off the steam.
To automatically make this dis-engagement during the movement of the lever F"
to close the valve H a cam R, loose on the shell S which supports the shafts F, G, is
connected by a rod R¹ with the governor, and from the dog P an arm P' extends
downward in the path of the said cam, and whenever the said arm .P¹ strikes the
cam R, as seen in Figure 4, the dog will be raised from its engagements with the
lever L and leave that lever L free to turn by the force of the spring L¹, as seen in
Figure 5, and which brings the shoulder on the lever L into engagement with the
lever F' on the opposite side, closing the valve H as seen in Figure 3, from which
time the two levers F¹ and L, with the valves E and H, move together in their
closed condition.
The action of the governor turns the cam R nearer to or further from the point
where the dog P engages the lever L accordingly as the engine runs faster or slower,
and if so slow that the cam is not reached before the completion of the stroke then
the valve will be open through the entire stroke, but as the speed of the engine
increases the cam R will be moved toward the dog and trip the dog accordingly.
The time of tripping may be adjusted in the usual manner of adjusting the action
of a governor. To provide against any interruption of the action of the governor,
as by a disconnection of the power which drives it, there is a second elevation R¹ on
the cam forward of the cam R, and which when the governor stops will be turned
up as indicated in broken lines, Figure 4, so that the arm P¹ will strike it at the
extremo forward movement of the lever F' and hold it away from its engagement
with the lever L, in which case the lever L would not be turned until the lever F1
should strike the shoulder thereon, and consequently the steam passage would not
be opened as the valve H would be closed from the start and through the entire
movement.
The valve His preferably arranged with springs between it and its guide or
shaft G the action of which is to force the valve H radially from the shaft so as to
make it self-packing or self-adjustable around the opening d.
The form of the valve E need not be that of a cylinder as shown, as that portion
of the cylinder below the active valve part is only necessary to support that part,
and if that active part be attached directly to the shaft which rotates the valve it
will be evident that the remainder of the cylinder may be dispensed with, it only
being essential that the valve shall be oscillating and substantially concentric with
the axis of the valve H.
While it is desirable that the exhaust should be arranged as a part of the steam
valve, it may be an independent valve, and this Invention is therefore not confined
to making the exhaust valve a part of the steam valve.
Having now described and particularly ascertained the nature of the said Inven-
tion, and the manner in which the same is or may be used or carried into effect,

page_text: I would observe in conclusion that what is considered novel and original, and
therefore claimed as the Invention is,-.
1. The combination of an oscillating valve provided with a steam passage, an
independent oscillating valve concentric with said steam valve but independent
thereof, and arranged so as to automatically close or open the said steam valve to
the cylinder, substantially as described.
3
2. The combination of an oscillating valve provided with both steam passage and
exhaust passage alternately presented to the cylinder port, an independent oscillating
valve concentric with said steam valve but independent thereof and arranged so as
to automatically close or open the steam way through the said steam valve to the
cylinder, substantially as described.
3. The combination of an oscillating valve provided with a steam passage, an in-
dependent oscillating valve concentric with said steam valve but independent thereof,
and arranged so as to automatically close or open the said steam passage through the
said steam valve to the cylinder, the said independent valve made self adjusting as
to its seat upon the steam valve, substantially as described.
4. The combination of the hollow shaft F, the steam valve in connection therewith
provided with a steam passage, a shaft G within said shaft F concentric thereto,
carrying the independent valve H with the lever F¹ on said shaft F in connection
with the eccentric of the engine, the lever L on said shaft G, the spring L, stationary
stop N, dog P hung upon said lever F', and the adjusting cam R in connection with
the governor, substantially as described.
5. The combination of the hollow shaft F, the steam valve in connection therewith
provided with a steam passage, a shaft G within said shaft F concentric thereto,
carrying the independent. valve H with the lever F¹ on said shaft F in connection
with the eccentric of the engine, the lever L on said shaft G, the spring L', stationary
stop N, dog P hung upon said lever F¹, and the adjusting cams Rand R' in connec-
tion with the governor, substantially as described.
In witness whereof, I, the said Edward Thomas Hughes, have hereunto set my
hand and seal, this Twenty third day of September, in the year of our Lord
One thousand eight hundred and seventy nine.