Improvements in and relating to Steam Engines, and Motors or Valve Gear for Operating the Valves thereof.
Year: 1891

page_text: Date of Application, 5th May, 1891-Accepted, 6th June, 1891
COMPLETE SPECIFICATION.
Improvements in and relating to Steam Engines, and Motors or
Valve Gear for Operating the Valves thereof.
I, HENRY BOLTHOFF, a Citizen of the United States of America, residing at
No. 1601 to 1611, 17th Street in the City of Denver, County of Arapahoe and
State of Colorado, United States of America, Manufacturer, 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 class of steam engines wherein the ordinary slide-
valve is used; and my said invention consists of certain novel parts and combinations
of parts, which are particularly pointed out and designated in the claims concluding
this Specification.
An important feature of my invention is the provision whereby the ordinary
slide-valve engine is made to operate automatically to regulate the speed of the
engine according to the power required, and thereby effect economy in the use of
steam.
Essentially, this provision consists of the division of the ordinary slide-valve into
separate parts operating independently of each other upon the same valve-face;
driven by the same eccentric and wherein two of the said valve-parts are controlled
by an independent motor to govern the quantity of steam required to do the work.
The multiple-valve is operated as a unit with all its parts moving together and
having two parts operating independently and automatically in reverse reciprocal
relation to cut off the steam at the main-ports of the cylinder.
The independent motor or steam-actuated cut-off valve gear, has a steam actuated
piston which is suitably connected to certain of the valve-parts to operate them
with quick movements to vary the cut-off sooner or later as the engine may require,
independently of the eccentrically operated valve-part, while at the same time the
said eccentric operates the several valve-parts as a unit, so as to render the engine
automatic in maintaining a given speed without interfering with the action of the
said eccentric in operating the valve in the usual manner.
Referring to the drawings-
Figure 1 is a vertical section taken through the valve chest of a steam engine,
showing the multiple slide valve-parts in the positions they occupy to admit the
steam to the cylinder, and the cut-off, or independently operating valve-parts closed
by the action of the independent motor, and the engine running light;
Figure 2 is a similar view, showing the multiple-valve-parts in the positions they
occupy with all the valve-parts full open at one end of the cylinder to admit steam
thereto when the engine is working under full load ;
Figure 3 is a horizontal section taken on the line, a, a, of Figure 1 ;
Figure 4 is a transverse section taken on the line y, y, of Figure 1 ;
Figure 5 shows the multiple-valve-parts separated; and
Figure 6 shows the valve chest ports.
In these drawings, A, is the steam cylinder, and B, is the valve chest, as in the
ordinary slide-valve engine; C, C1, C2, C3, are the steam ports leading to the
cylinder, and D, D', D2, D3, are the ports leading to the exhaust, E. I use an
ordinary D-valve preferably because it is the simplest known form of slide-valve,
and, in the example shown, I construct it of three separate parts for operating the
ports as a unit. The centre part, a, of the valve occupies the position or place of
the ordinary slide-valve; while the other two independently movable valve-
parts, b, and c, are arranged on each side of the centre valve-part and are operated
on the same ports to cut off the steam at any given point of the stroke of the piston,
for the purpose of controlling the speed of the engine according to the power

page_text: required. The centre valve-part, a, is of the ordinary D-slide-valve pattern to
operate the ports, C, C, D, D', at both ends of the cylinder, but as a part of my
improved multiple-slide-valve, it is only about one-fourth the width of such ordinary
slide-valve. The object of thus reducing the width of this centre valve-part is for
the purpose of admitting only a sufficient quantity of steam to operate the engine
when the cut-off valves are closed; and for the further purpose of admitting steam
to the cylinder at its proper point and time of receiving the steam at each end of
the stroke. This centre valve-part, a, has a constant and given stroke not subject
to the control of the motor device which is connected to and operates the
independent cut-off valves, b, c, but is operated and controlled solely by the
eccentric. The independent valve-parts are of greater width and of less length
than the centre valve-part and are arranged to operate on the same seat and over
the same ports as the centre valve-part; and are also arranged to be operated as
parts of the centre-valve by one and the same eccentric.
The centre valve-part has the usual valve-rod, e, and guide-bar, f, the latter
working in fixed guide-boxes, g, y, and to this guide-bar, f, is pivoted a cross-
head, h, to the ends of which the cut-off valve-rods, i, i, are jointed. An arm, j,
extends from this cross-head, h, so as to form a lever which is connected by a
vertical rod, k, to the piston-rod, 1, of a motor piston, m, which I prefer to operate
by steam for the purpose of operating the cut-off independent valve-parts in a way
which I shall presently describe as being the special function of the motor device.
The centre valve-part guide-bar, f, is connected to the eccentric, n, by the rod, p,
which is pivoted to said guide-bar, so that the eccentric thereby becomes the
means of operating the several valve-parts as a unit; while the lever cross-head, h,
connection is permitted to give an independent movement to the independent or
cut-off valve-parts, and without interfering with the action of the regular slide-valve
centre-part. In the position shown in using the valves, the centre valve-part is
supported by and slides upon the upper edge of the inner cut-off valve, and upon a
guide-rib, q, on the valve-seat; the outer or back cut-off valve-part is supported by
and slides upon the centre valve-part; while the forward or inner cut-off valve-
part is supported by and slides upon the bottom of the steam-chest or other suitable
support. The valve parts, as shown, are arranged to operate both as a unit and
independent of each other, and they ride upon the same seat side by side, each
valve covering its own receiving and exhaust-ports, which are divided by longitudinal
bridges, so that each valve covers one half of the bridge and its own port. Each
of the valve-parts is formed with the usual D-exhaust for operating the exhaust
ports, D, D1, D2, D3, in the usual way of the ordinary slide-valve. The motor
device above referred to as shown consists of a cylinder, 1, having a piston, m, which
by its piston-rod, 1, is connected as stated by the rod, k, to the cross-head lever, j,
and a smaller cylinder, 4, containing a piston or plug-valve, 5, which is connected
by a valve-rod, 6, to a governor 7. These cylinders communicate by an inlet-
port, 8, and an exhaust port, 9, at the lower ends thereof, and which ports are
controlled by the piston or plug-valve, to admit the live-steam by the passage, 10,
and to exhaust by the passage 11. The governor may be of the ball-type; and it
will be understood that in this particular construction of steam motor, its piston is
raised by steam and descends by its own gravity assisted by weight or spring force.
These forces may be used together or separately, and when used separately, the
spring 12 is secured to the floor or engine-frame, and is connected to the lower end
of the piston connecting-rod, k, by a link 13. When weights are used they are
preferably placed upon the upper end of the piston rod as at 14. While the
employment of this force is primarily for effecting the quick descent of the piston
to impart a quick action to the independent valve-parts to maintain a uniform speed
of the engine; yet this force is used as a means of changing the speed of the engine
by increasing or decreasing the tension of the spring, or increasing or diminishing
the weight upon the piston-rod, as the engineer may desire. The motor device is
intended to be mounted and suitably supported upon the engine-frame.

page_text: The passage, v, seen at the upper end of the motor-cylinder is for the purpose
of permitting the outflow of the water which may accumulate in the cylinder above
the piston from steam which may leak by the piston; and this water passing into
the case of the plug-valve, is permitted to pass therefrom through a central
passage, w, in said valve to the exhaust, and thereby relieve the said piston from
being impeded in its up-stroke, which would result from such accumulation of
water.
In the operation of the engine it will be seen that the eccentric operates
positively and continuously all the valve-parts and when the valves are in the
position shown in Figure 1 the engine will have attained its given speed, and steam
is now entering only the forward end of the cylinder through the port, C, which,
at this moment is opened, with the crank on the downward quarter-stroke toward
the engine-cylinder. The crank making a half revolution will reverse the movement
of the valves and open port, C¹, and these ports not being sufficiently large to
supply the engine under a load and keep it up to its full speed, it will thereby be
slowed up for the want of a greater quantity of steam. This action of the engine
will cause the governor to be correspondingly slowed and thereby operate its
plug-valve so as to close the receiving port and open the exhaust, permitting the
piston to descend and thereby vibrate the lever cross-head to operate the independent
cut-off valve-parts. The motor-piston descends by its own gravity which is sup-
plemented by the force of the spring, or of the weight, or of both together. The
descent of the piston depresses the cross-head lever and rocks the cross-head,
thereby drawing the independent valve-parts, b, and c, towards each other, so as to
first open the port, C2, as seen in Figure 2, the eccentric in the meantime moving
the multiple-valves as a unit towards the eccentric, and thereby quickly close the
ports, C, and C2, and open the ports, C₁, and C³. These simultaneous movements
of the valves independently of each other, and together as a unit, causes the
independent valve-parts to open their ports, C², and C³, alternately, at each end of
the stroke, and the centre valve-part to open its ports C, and C, alternately at
each end of the stroke. The movements which I have stated of the independent
valve-parts towards each other will continue during the descent of the piston until
the engine has attained its speed, and when this has taken place the governor-
balls will be raised by the centrifugal force, causing the plug-valve to descend and
close the exhaust port and open the receiving port and raise the piston, thereby
reversing the operation of the independent valve-parts, b, and c, moving them from
each other, for the purpose of admitting just steam enough into ports, C², and C³,
to carry the load and to maintain a given speed of the engine. In this operation
the centre valve-part at the same time is caused to open its ports and is controlled
solely by the eccentric which constantly imparts its motion to all the valve-parts,
to operate them as one valve. While, therefore, all the valve-parts have an equal
stroke from the eccentric, the independent valve-parts have a relative lengthening
and shortening stroke by the action of the lever cross-head and it is this movement
which produces the opening and closing of the ports, as the motor device may be
caused to act by the action of its governor.
It is in this way that I make an automatic engine of the ordinary slide-valve
type; because while the three valve-parts operate each as a cut off and a receiving
valve, yet two of these co-acting valve-parts, that is to say the independent motor-
device controlled valve-parts, act to cut off sooner or later as the motor-device may
determine, and thus keep the engine at a uniform speed under any given speed or
load while the eccentrically operated valve-part acts with an unchanging move-
ment and uniform travel. The construction by which I obtain this important
advantage is such as to permit its application to slide valve engines now
in use.
While the spring or weight-force supplements the weight of the piston to give
it a quick descent, which is an important matter to transmit such quick movement
to the independent valve-parts, the spring is also important in maintaining a steady

page_text: action of the piston while under the pressure of the steam, which would otherwise
be liable to transmit a trembling or unsteady movement to the said valves.
The motor operated valve-parts are wider and shorter than the centre eccentric-
operated valve-part, to obtain the advantage of compactness of valves, with com-
paratively wide side valves and long ports operated by them to admit of the passage
of the full force and volume of steam from the steam-chest to the cylinder at the
moment the valve is opened.
While the three valve-parts operate each as a cut-off and a receiving valve, yet
two of these co-acting valve-parts, that is to say, the independent motor controlled
valve-parts, act to cut off, sooner or later, as the motor may determine, and thus
keep the engine at a uniform speed under any given speed or load; while the
eccentrically operated valve-part, acts with an unchanging movement or uniform
travel.
It is important to notice that the eccentric operates the multiple slide-valve
continuously as a unit, so that the action of the governor is at all times communicated
to the moving parts of the valve, and thereby is relieved from the strain, which
would be required to start such valve-parts; and this advantage is enhanced
because the governor may at any time cease to move the valves independently of
the action of the eccentric, for, when the load is constant and the steam regular
in pressure, the multiple-valve under such conditions will not require change from
the motor and hence the latter will be practically inoperative in its functional
relation to the valves. But when such functional relation is brought into action
such action is directed to moving valve-parts, so that the eccentric and the
governor move and operate in harmony to produce an automatic slide-valve
engine.
It is evident that immaterial departures may be permitted from the general
construction and arrangement of parts contributing toward my invention, and for
this reason I do not wish to be understood as limiting myself thereto in precise
detail.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim is :-
1. A multiple slide-valve for steam engines, the several valve-parts whereof
operate independently side by side upon the same valve-seat and each controlling
its own receiving and exhaust ports, for the purpose stated.
2. A multiple slide-valve for steam engines, the several parts whereof operate
as a unit, yet independently of each other, side by side, upon the same valve-seat
and each controlling its own receiving and exhaust ports, for the purpose
stated.
3. In a steam-engine, a slide-valve composed of three co-acting parts arranged to
operate as a unit, yet independently of each other, side by side, upon the same
valve seat, each controlling its own receiving and exhaust ports, for the purpose
stated.
4. In a steam engine, a slide-valve composed of three co-acting parts arranged to
operate as a unit, yet independently of each other, side by side, upon the same
valve-seat, each controlling its own receiving and exhaust ports, the centre-valve-
part having a greater length than that of the side valve-parts, for the purpose
stated.
5. In a steam engine, a slide-valve composed of three independently operating
co-acting parts arranged to operate side by side, upon the same valve-seat, each
controlling its own receiving and exhaust ports, and operated as a unit by separate
valve-rods, for the purpose stated.
6. In a steam engine, the combination, with a multiple slide-valve, the several
parts whereof are arranged to operate side by side, upon the same valve-seat, and
each controlling its own receiving and exhausting ports, of a motor having a steam

page_text: actuated piston, and suitable connections for said piston-rod and valves, for operating
the same in the way and for the purpose stated.
7. In a steam engine, the combination, with a slide-valve composed of three
independently co-acting parts, arranged side by side, upon the same valve-seat,
each controlling its own receiving and exhausting ports, and having a separate
valve-rod, of a motor having a steam actuated piston, a rod pivotally connected
with said piston-rod, a rocking lever cross-head jointed to said rod and to the side
valve-parts and pivoted upon the guide-bar of the eccentric connected valve-part,
and a governor controlled valve for operating said motor piston, in the way and for
the purpose described.
8. In a steam engine, the combination, with a slide-valve composed of three
independently co-acting parts, arranged to operate side by side, upon the same
valve-seat, each controlling its own receiving and exhausting ports and having
separate valve-rods, of a motor having a steam actuated piston, suitable connections
for said piston-rod and valves, a force supplementing said piston and acting with a
downward pressure, and a governor-controlled valve for operating said piston-
motor, in the way and for the purpose stated.
9. In a steam engine, the combination, with a multiple slide-valve, the several
parts whereof are arranged to operate side by side, upon the same valve-seat, each
controlling its own receiving and exhausting ports, and means for operating them
as a unit and independently of each other, consisting of the eccentric, a motor
having a steam-operated piston, suitable connections for said piston-rod and valves,
and a governor-valve for operating said motor-piston, substantially as described.
10. In a steam engine a multiple slide-valve the several parts whereof are
arranged to operate side by side, upon the same valve-seat, each controlling its own
receiving and exhaust ports, and an eccentric operating the several valve-parts as a
unit, in combination with a suitable motor for independently controlling parts of
said multiple-valve during their movements as a unit, substantially as described and
for the purpose specified.
11. In a steam engine, the combination with the eccentric, a multiple slide-valve
continuously operated as a unit by said eccentric, substantially as described.
12. A slide-valve steam engine constructed to operate automatically to regulate
the speed according to the power required, consisting essentially of the following
elements, viz., a multiple slide-valve, the several parts whereof are arranged to
operate side by side, upon the same valve seat and each controlling its own
receiving and exhausting ports, an eccentric for operating said valves as a unit, a
steam actuated piston connected to operate two of said valve-parts independent
of said eccentric, a force supplementing said piston, acting with a downward
pressure, and a governor-controlled valve, for operating said piston, substantially
as described.
13. In a steam engine, a slide-valve composed of three co-acting parts arranged
to operate side by side upon the same valve-seat, and having an equal stroke from
their connected eccentric, the side-valve parts having a relative lengthening and
shortening stroke independent of the central valve-parts, in combination with an
independent steam actuated piston device, connected to said side valve-parts, for
operating them in the way and for the purpose stated.
14. The steam-actuated piston-motor or cut-off valve gear herein described, the
same consisting of a steam cylinder, a piston operating therein by steam admitted
to one end only of said cylinder, a governor-controlled valve for operating said
piston, a force supplementing said piston-rod, acting thereon with a downward
pressure, an eccentric operated-rod, and suitable connections with said piston-rod
and said eccentric-rod, for transmitting the movements of said piston to the device
operated thereby, substantially as described.
15. The combination with the steam-cylinder having an inlet and exhaust port at
one end only, a piston operating therein, a governor-controlled valve for operating
said piston, and a force supplementing said piston and acting with a downward

page_text: pressure thereon, of a rod pivotally connected to the piston rod, an eccentric
operated rod, and a suitable lever device pivotally connecting the said piston-
operated rod, the eccentric operated rod, and the device operated by said piston
connections, substantially as described.
1001
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.