Improvements in Electric Stop Motions for Engines.
Year: 1896

page_text: Date of Application, 13th Apr., 1896-Accepted, 23rd May, 1896
COMPLETE SPECIFICATION.
Improvements in Electric Stop Motions for Engines.
I, LOUIS ST. PETER of 19 Webster Street, in the City of Springfield, County
of Hampden, and State of Massachusetts, United States of America. 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:-
The object of this invention is to devise stop motion devices which shall be
applicable to a large variety of valve mechanisms as found in different engines,
and which shall be of the utmost simplicity and compactness and susceptible of
inexpensive production.
The invention consists in constructions and arrangements of parts for
combination with ordinary valve-operating mechanisms of steam engines, all as
will hereinafter more fully appear and be set forth in the claims.
In the accompanying drawings,
Figure 1 is a perspective representation of a portion of the ordinary valve
mechanism and governor of the common Corliss engine with the present improved
stop motion so combined therewith that the regulating action of the governor
upon the valve mechanism. will not be affected by the applied stop motion, and so
that upon occasion the stop motion will operate to absolutely and instantaneously
stop the engine when operated by the push button to close the circuit.
Figure 2 is an enlarged view showing the manner of connection between parts
hereinafter referred to.
The ordinary valve and governor mechanisms, as shown, will be briefly pointed
out as identified by numerals of reference and the parts constituting the stop
motion will be referred to by letters of reference.
As well known in this and other types of engines there are one or more valves
alternately opened.
9 represents one of the valve-operating rods which is hung to an arm, 10,
mounted to rock on the shaft, or stud, 12. The part, 14, has, during the running
of the engine, a regular reciprocatory movement and engages in each of its strokes
a part which causes the rocking of the arm, 10, to properly and in good time effect
the lifting of the valve-operating rod, 9. The periodicity, or extent in duration
of the lifting of the said valve-operating rod, 9, is controlled by the governor
which acts upon the oscillating collar, 15, which is provided with a cam, 16, that
so acts against the upper jaw, 17, of the two-jawed part, 20, that by reason of the
degree of oscillation of the part, 15, and the swinging of the part, 20, the duration
of the engagement by the grabhook may be longer or shorter and in fact when
the part, 15, is sufficiently far oscillated the part, 20, will be so far swung that
there will be no effect to rock the arm, 10.
The governor, 22, in rising, through the rod, 23, upwardly swings the crank-
arm, 24, of the rocker-shaft, or stud, 25, on which is the lever, 26, and to one arm
of this lever, the connecting rod, 27, is by its one end secured, while its other
extremity is connected to a radial projection, 28, of the oscillating part, 15, which
carries the cam, 16.
All of these devices are very common and well known, as well, also, as their
mode of operation, and it is understood, of course, that during the ordinary
running of the engine, the degree of oscillation of the part, 15, as occasioned

page_text: through the mechanism mentioned, by the raising or lowering of the governor
balls, is slight, although in this class of engines, as well known, should the
governor balls be so far raised beyond their normal limits of movement, the
oscillation of the part, 15, will be so great as to cause on each reciprocatory
movement of the parts, 14 and 20, no engagement and tripping of the grab-hook
and consequently no lifting of the valve-operating rod, 9, whereupon no steam
would be admitted to the cylinder.
It will be stated, preliminarily, that the action of this stop motion is such that,
upon its operation, it so elevates the rod, 23, as to effect the required oscillation
of the part, 15, to prevent the engine from taking steam, and the devices operating
to this end will be now described in detail.
a, represents a roller which is adapted to run on the horizontal track, or bar, b,
which may be a part of the framing, 3, of the engine. This roller is journaled
in the lower end of the rod, d, which at d2, is pivoted to the aforesaid vertical
rod, 23, which is an adjunct of the governor.
A cord, or other flexible connection, f, is connected to the rod, d, near the
roller, a, or the part to which it is journaled, thence passing around the
sheave, g, its depending portion, 2, being provided with the weight, h, of
considerable preponderance over the force required to raise the governor balls.
This depending portion of the flexible connection has the eye, f³, which is
adapted to be hung upon the hooked arm, 2, of the lever, i, which is pivoted
at 23.
j represents an electro-magnet for which, k, is the armature pivotally mounted
at 2, and so poised as preferably ensured by the application of the spring, k³, that
the armature normally stands well away from the end of the electro-magnet and
serves as a trigger to restrain the lever, in its position indicated in the drawing
in which it supports the weight, h.
It will be here noted that when the weight, h, is hung upon the hooked arm,
of the said armature-restrained lever, the cord connection, f and i³, between the
eye, f, and the roller, a, is sufficiently slack to permit the slight vibratory
movements of the roller, as occasioned during the ordinary action of the governor
by reason of the said roller being linked to the said rod, 23.
The electro-magnet is comprised in an open circuit constituted by the wires, x, x,
which also comprise a battery, or other generator, y, and a circuit closing device
indicated at z, in the form of an ordinary push-button.
The operation of this electrical stop motion is evident on an inspection of the
drawings, although it will be stated as follows:
Assuming a person in a place distant from the engine room, as, for instance, on
an upper floor in the factory, desires to instantly stop the engine because of
'some accident, as perhaps, on the occasion of an operative becoming caught in the
machinery:
Upon simply pressing the button at z, closing the circuit and energizing the
electro-magnet, the armature, k, is drawn to the electro-magnet and out of its
restraining position for the lever, i, which then so swings as to leave the cord, f
fully subject to the entire draft action of the weight, h, which causes the rod, d, to
force the rod, 23, so far vertically as to, through parts 24, 25, 26 and 27, so far
oscillate the part, 15, as to prevent the further taking of the grab-hook upon the
reciprocatory movements of the part, 14, in which event, of course, the valve-
operating rod, 9, (or as the engine is usually equipped, the two of such rods,)
will not be elevated and by reason of the cessation of the passage of steam to the
cylinder, or cylinders, of the engine, the latter will stop.
In practice the absolute stopping of the engine is effected in from 10 to
20 seconds.
The electro-magnet is axially horizontal while the armature is vertically bung
'so as to receive and resist endwise the stress of the lever, as established by the
weight, hence this arrangement conduces to simplicity and desired lightness of
construction without dispensing in any measure with the required strength.

page_text: 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. In an electrical stop motion for engines, the combination with a valve-
operating device of the engine, of an electro-magnet and armature, electric
conductors for forming a circuit, means for closing the circuit, a lever to act on
the valve-operating device and engaged by the armature of the electro-magnet,
all so that on the closing of the circuit and energizing of the magnet the armature
is withdrawn from its lever-engaging position leaving the lever free to be swung,
substantially as described.
2. In an electric stop motion for engines, the combination with the track-bar, b,
and a reciprocatory part, as 23, of the governor mechanism, of the rod, d, pivoted
to the said reciprocatory part and having the roller to move in said track-bar,
the sheave, g, the lever, i, the weighted cord, f, connected to the said rod, d, and
having a guiding engagement with the sheave and having in its depending portion
the eye,, and provided at its portion therebelow with the weight, h, the electro-
magnet having its armature adapted for a restraining engagement with said
lever, f, and electric apparatus for duly energizing the said electro-magnet,
substantially as described.
Dated this 30th day of August 1895.
LOUIS ST. PETER.
Haseltine, Lake & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.