Improvements in and relating to Electric Circuit-controlling.
Year: 1890

page_text: Date of Application, 24th June, 1890-Accepted, 27th Dec., 1890
COMPLETE SPECIFICATION.
Improvements in and relating to Electric Circuit-controlling.
:
Apparatus.
I, WILLIAM WALTER ALEXANDER, residing at the City of Kansas, in the County of
Jackson and State of Missouri, one of the United States of America, Electrician, 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 devices for mechanically operating electric circuits; and
the objects of my improvement are to produce a simple and reliable electro-mechanical
apparatus adapted to operate various mechanisms by secret or predetermined
combinations of short and long impulses made upon a press button or upon an
electric key indirectly acting upon a toothed wheel and pawls and levers as hereinafter
described.
Referring to the accompanying drawings:-
Figure 1, is a side view of an apparatus constructed in accordance with my invention;
Figure 2, is a modification of the means for connecting the armature with the
mechanism;
Figure 3, is a top view of the apparatus ;
Figure 4, is a vertical section of the motion-controlling dasher;
Figure 5, is a plan view of said dasher.
Sheet 2. Figure 6, is a side view of the apparatus slightly modified, and in said
view the ratchet lever is broken away to show the pawl;
Figure 7, is a top view of the same;
Figure 8, is a front view of the combination wheel consisting of two discs connected
by a pin projecting from the face of one disc and entering a slot in the other, said
discs being shown in the relative positions they occupy when they are to be returned
to normal position, thereby making it impossible for the retaining pawl to enter any
of the notches between the teeth;
Figure 9, is a front view of the disc, having in its periphery a series of teeth at
irregular intervals.
Sheet 3. Figures 10 to 20, show modifications of toggle-lever connections to be
used in combination with the circuit-controlling apparatus to equalize and render more
uniform the magnetic attraction of the electro-magnet for the armature during the
entire arc of travel of the operating lever, or while the toggle-lever connections are
subjected to resistance.
In said drawings, B, represents a base upon which is mounted an electro-magnet, E,
retained by its heel-plate, H. Upon said base is placed a post, P, to which the
rmature lever, A2, is pivoted, the armature, A, being secured as usual to said lever.
To support many of the parts of the device, a back plate, B2, is retained vertically
pon the base, B. Nearly centrally of the plate, B2, there is pivoted a shaft, N,
aving one end supported by the post, B³, said shaft, N, carries a toothed wheel, 4,
pon the periphery of which the desired combination of notches as, I, I³, 1³, I*, is
ormed, said notches are arranged at irregular intervals, the distance between some of
hem representing short pulsations or strokes made by the propelling mechanism
while the distances between the others represent long pulsations and said pulsations
nay be caused by direct mechanical action or by electro-magnet action. To rotate
he toothed wheel, 4, in one direction, a hair-spring, R, is mounted upon the shaft of
aid wheel, and has one end secured to said shaft while the other end is secured to the
ost, Ba
To rotate the toothed wheel, 4, in the opposite direction, as when a series of strokes
re made upon the lever, A2, and permit said wheel, 4, to be rotated; an annular
over, F, is pivoted at, f, upon a pin projecting horizontally from the plate, B². The

page_text: opposite end of said lever is united by means of a connecting rod, G, with the lever, 6.
One end of the lever, 6, is pivoted upon the shaft, N, and it carries adjacent to its
outer end a pawl, P³, pivoted thereto. Said pawl is to advance the toothed wheel, 4,
when the lever F, begins to descend. For this purpose the pivoted end of the pawl, P³,
has a spring, p, one end of which is secured to the lever, 6, which throws the curved
end of the pawl into engagement with propelling teeth, i, of the toothed wheel and
the latter is rotated. Said pawl, P2, has a T-shaped head, the arm, t, of which comes
at the upper end of its course in contact with an adjustable stop-pin, s, secured to the
back plate, B2, which throws the curved end of the pawl out of engagement with the
wheel. 4; and being out of engagement it remains in that condition until the lever, F,
is actuated upon, and begins to descend. When it has reached the lower end of its
course the arm, 2, of the T-shaped head of the pawl, P2, comes in contact with the
stop-pin, s2, adjustably secured to the back plate, B2, which tilts the said pawl out of
engagement with the toothed wheel. But before said disengagement a back rotation
of said toothed wheel under the impulse of the hair-spring, R, is prevented by the
retaining pawl, Q Said pawl, Q, is pivoted to the back plate, B2, at, q, and one end
of said pawl is adapted to drop by gravity into one of the notches of the toothed
wheel. The free end of lever, F, is normally kept elevated by pressure brought to
bear against its short arın, F. Said pressure is produced by the spring, S, having
one end secured to a stationary part, as the post, B³, and the opposite end to the
lever, A, as the upper end of said lever abuts against the short arm of lever, F.
As it is preferred that the free end of said lover, F, should descend by gravity, a
weight, W, is placed adjustably thereon, so that when the upper end of the lever, A²,
is drawn backward either by the armature, A, or by pressure upon the push button, L,
transmitted by means of the pivoted lever, 12, and connecting rod, L³, said lever will
descend until arrested by the stop-pin, T2, in a similar manner as a stop-pin, T, arrests
it at the upper end of its course.
To prevent the lever, F, from descending too rapidly by gravity when approaching
the end of its course a dash-pot, K, is used into which is placed a liquid, and in said
liquid a valve or loose piston, D, provided with perforations, d. in said piston is retained
loosely by the piston-rod, D2, the upper end of which is pivoted to the end of the
lever, F. Upon the piston-rod is also mounted but rigidly secured thereto a disc, D³,
adapted to close the perforations, d, in the loose piston, D, when said disc reaches said
piston, said disc and piston acting then together as an obstruction against the rapid
descent of the free end of the lever, F. In the ascent of the piston-rod the
perforated portion, D, offers but little obstruction as the perforations, d, are opened as
soon as said piston starts on its upward course and permit the liquid to pass freely
therethrough.
In Figure 2, the lever, A2, is connected to the armature, A, by means of a toggle, V,
the purpose of which is to equalize the magnetic attraction of the electro-magnet for
the armature and render the same more uniform during the entire arc of travel of
lever, A².
In operating the device, if the toothed wheel, 4, and the lever, F, are in normal
position as shown in the drawings, and said lever is allowed to descend. it will travel
rapidly, about one-half the distance between the stop-pin, T, and, T2, and then the disc, D³,
secured to the piston-rod, D³, will strike upon the loose disc, D, which, during said
rapid descent has remained almost stationary in the liquid, and then the piston-rod and
the lever, F, will descend more slowly, and as said lever, F, is united to the lever, 6,
by means of the connecting rod, G, said lever, 6, and its pawl, P2, are also carried
downward, and as said pawl, P2, immediately from the start engages the teeth, i, of
the wheel, 4, said wheel will have been propelled against the tension of the spring, R,
the distance of one tooth or one notch, and the retaining pawl, Q, will have entered
the next notch, 12, after the half of the full travel of the lever, F; and now if the
lever, F, is made to ascend (by the action of the spring, S,) the wheel, 4, will be held
in that position by the pawl Q. But if the lever F is allowed to descend the entire
length of its course (which action would be a false move of the operator) when the
pawl Q was in engagement with the notch I the wheel 4 will have been propelled the

page_text: distance of two teeth or notches, and the retaining pawl will rest on the wide surface I³.
And, while the pawl Q is in that position, the wheel 4 will immediately turn back to
normal position under the impulse of the spring R, when the lever F, reaches the end
of its course, (the adjustable stop-pin s will have met one of the arms of the pawl P²
and disengage it from the wheel 4). During this action, the retaining pawl being
nearly counterbalanced and acting sluggishly in consequence thereof will not enter the
notches in the wheel and will not arrest its motion. Therefore the wheel will return
to its normal position with its pin e in contact with the post B³.
Starting from this normal position if a short
press-button, the lever descends only about one
pressure or pulsation is made upon the
of its course and the pawl Q will
fall into the notch I2 and prevent a back motion of the wheel: the push-button being
then released the lever F will ascend again to the top of its course.
If a long pulsation or pressure is then made upon the press-button and the lever F
is thus allowed to descend its whole course, the pawl will enter the notch '13 and
prevent a back motion of the wheel. The push-button being released after the long
pressure thereon, the lever Fascends to the top of its course against the pin T. Now
if a short pressure is made upon the press-button and the lever F is allowed to descend
only one half of its course the pawl Q will leave the notch 13 and enter the notch I*
and prevent a back motion of the wheel, while the lever F returns again to its normal
position.
During the forward movement of the wheel 4 it has carried its contact pin C
(which projects from its face) around until said pin is in close proximity to the contact
spring C secured to, but insulated from the post B³. And if the lever F is then
allowed to descend, either one half or the whole of its course the pin (%, in either
case, will be brought in contact with the contact spring C, thereby closing the circuit
as follows: From local battery L B to electro-magnet É M to contact spring C,
contact spring C2, metallic wheel 4 and thence through its shaft N and hair-spring R
to the post B and through the base B and wire X, back to the other pole of the
battery. Said magnet E M is adapted to attract its armature A which is shown as
retaining the lock-bolt A' in a locked position. When the device is properly operated
the armature is attracted and allows the lock-bolt to be retracted.
By the final movement made by the lever F and the rotation of the wheel 4, the
pawl will have left the notch I and rest upon the smooth periphery 18 of the wheel,
now when pawl P2 is disengaged, the wheel acting under the tension of spring R will
return to normal position, as the pawl Q cannot enter the notches and arrest it, on
account of the rapid reverse motion of the wheel, and consequently the circuit will
be broken.
If the wheel 4 is propelled the distance of two teeth when the combination of
notches is arranged as represented at I and I2 with a blank space following, the wheel
will not be prevented from returning to normal position: and if the pawl Q is standing
in the notch 12 and the wheel is propelled the distance of one notch, it will also be
allowed to return to normal position: and the same results will be attained for the
entire combination..
In Figure 1 a transmitting key T K is shown with a line and battery to operate the
device from a distance and in Figure 2 is shown at T K a modification of the trans-
mitter, also with line and battery.
In the modification shown in Sheet 2 the shaft N carries rigidly attached thereto a
disc 4 having upon its periphery a series of rectangular face teeth h of uniform size
having notches of uniform size between them. To rotate the toothed disc 4 in one
direction the spring R is mounted upon the shaft of said disc and has one end secured
o said shaft while the other end is secured to the post B³.
נ'
To permit the disc 4 to respond or to rotate only by a certain combination of short
nd long pulsations or strokes made by the propelling mechanism, a disc 4 is provided
vith a predetermined combination of rectangular face teeth his mounted loosely
longside of the disc upon a shaft N and has a sleeve to which is secured the friction
wheel HⓇ that bas its edge clasped by springs he attached to a support secured to the
back plate B². To rotate. the disc 4 in the opposite direction of that given by the

page_text: spring R as when a series of attractions are made upon the armature A, and permit
said wheel to be rotated: the angular lever F is united by means of the connecting
rod G with the U-shaped lever 6. Each end of said lever 6 is loosely pivoted upon
the shaft N, and it carries adjacent to its outer end the pawl P2 pivoted thereto. Said
pawl is to advance the toothed disc 4 when the lever F begins to descend its back
rotation is prevented by the retaining pawl Q. Said pawl Qis pivoted to an arm 6³
projecting from the back plate B2, and one end of said pawl is adapted to drop by
gravity, or under the impulse of spring q into one of the notches of the toothed disc.
As it is preferred that the long end of the lever F and parts attached thereto, should
be counterbalanced, (for delicate adjustment and permit the device to be operated in
various positions) the lever F has a rearwardly extended arm F3 upon which a weight W
is adjustably mounted. A spring w has one end attached to the lever F and the
other to the arm 63 projecting from the back plate, to start said lever on its downward
course.
In operating the device if the toothed discs 4 and 5 and the lever F are in normal
position as shown in Figures 6 and 7 and said lever is allowed to descend, the lever 6
and its pawl P is also carried downward, and as said pawl immediately from the start
engages the teeth of the disc 4, said disc will have been propelled against the tension
of the spring R, the distance of one tooth or notch, and the retaining pawl will
have entered the next notch. And now if the lever F is made to ascend (by the
action of the spring S) the discs 4 and 5 as well as the disc H will be held in that
position by the pawl Q. But if the lever F is allowed to descend the entire length of
its course (which action would be a false move of the operator according to the present
combination) the wheel 4 will be propelled the distance of two teeth or notches and
the retaining pawl will rest on the wide surface or double tooth 8 of the disc 5, and
cannot engage in any of the notches of the disc 4. And if, while the pawl Q is in
that position, the pawl P2 being then disengaged, the disc 4 will immediately turn
back under the impulse of the spring R. But while this takes place the disc will
remain stationary (as its companion disc H is clasped by the springs h) until the
pin fprojecting from the face of the disc 5 has reached the lower end of the slot f* in
the disc 4 (as shown in Figure 8). The disc 4 then carries the disc 5 around there-
with, and the latter disc acquires a certain momentum so that when the pin e of the
dise 4 strikes the side of the post B³, the disc 5 is carried partly around until the
pin reaches the upper end of the slot ƒ in the position shown in Figure 6, and
immediately after, the lever F returns to the top of its course against the stop-pin T.
Starting from this normal position, if a pulsation or pressure of short duration is
made by the armature (attracted by the electro-magnet), the lever descends only about
one half of its course and the pawl Q will enter notch 12 and prevent a backward
motion of the disc when the armature A is released and the lever F ascends to the top
of its course, (sliding the pawl P2 back over the teeth).
If a long pulsation is then made by the armature and the lever F is thus allowed to
descend its whole course the pawl Q will enter notch 3 immediately before the pawl P2
is disengaged from the disc by the stop-pin S2, and prevent a back motion of the disc,
the armature being released after the long attraction thereof, the lever F ascends to
the top of its course against the pin T carrying the propelling pawl P2 back over the
teeth. Now if a short attraction is made upon the armature and the lever F is allowed
to descend only one half of its course, the pawl Q will leave the notch and enter the
notch and prevent a back motion of the disc while the lever return again to its
normal position.
Now if a long pulsation or attraction is made upon the armature and the lever F is
thus allowed to descend its whole course the pawl Q will enter the notch is and prevent a
back motion of the disc when the pawl P2 is disengaged as described. The lever F
is then permitted to ascend to the top of its course as before. Now if a short attraction
is made upon the armature and the lever is allowed to descend only one half of its
course, the pawl Q will leave the notch and enter the next notch and prevent a
back motion of the disc when the lever returns to normal position.
Now if a long pulsation or attraction is made upon the armature and the lever is

page_text: allowed to descend its whole course; the pawl will enter the notch ' and prevent a
back motion of the disc.
During the forward movement of the wheel 4, it has carried its contact pin C³
(which projects from its face) around until said pin is in close proximity to the contact
spring C, (secured to) but insulated from the post B³. And if the lever F is allowed.
to descend the pin 2 will be brought in contact with the contact spring C, thereby
closing the circuit as follows: From local battery LB to electro-magnet E M, wire X²,
to contact spring C, contact pin 02, metallic disc 4, and thence through its shaft N
and hair-spring R to the post B³, and through the wire X2, back to the other pole of
the battery. Said magnet E M is adapted to attract its armature A* which is shown
in full lines as retaining the lock-bolt A in a locked position. When the device is
properly operated, the armature takes the position shown in dotted lines and allows
the lock-bolt to be retracted.
By the final movement made by the lever F and the rotation of the disc 4 the pawl Q
will have left the last notch 7 (in which it was) and rest upon the smooth periphery of
the disc 5 now if said lever is allowed to ascend, the disc acting under the tension
of the spring R will return to normal position as the pawl Q cannot enter any of the
notches and arrest it.
:
Whenever the pawl Q is not in one of the notches, the disc 4 starts back alone the
length of the slot f, then the discs 4 and 5 temporarily rotate back together as a
single wheel and assume the position shown in Figure 8 and the pawl Q cannot enter
any of the notches, and said position of discs is changed only after the stop-pin e
strikes the post B³, when the momentum of said disc 5 carries it forward the length
of the slot f*.
If the disc is propelled the distance of two teeth when the combination is
arranged for one tooth, the discs will not be prevented from returning to normal
position, and the same result will be obtained if any inistake is made in any part of
the combination.
To provide means to compensate for the increased attraction that an armature
receives from an electro-magnet as it approaches the pole thereof and afford facilities
for the adjustment of the parts when worn by use, I employ in combination with the
separate controlling mechanism, the constructions shown in Sheet 3, Figures 10 to 20
can be used.
2
In said drawings B represents the base of the device upon which is mounted the
support or heel iron H shown in plan in Fig. 114 the latter iron carrying the electro-
magnet E having the core C. The armature is represented at A, and the toggle at T;
the latter consisting of at least two arms and of which the arm 2 has one end
pivoted to the rigid post p that can be made adjustable as shown in Figure 104, the
lower end of said post passing through a slot in the base B. The arm 2 has a body
or lateral extension t' to which the resistance R is attached. The extension t may be
made in the same plane as the arm t2 or it may be on one side thereof by having it
rigidly attached to the pivot shaft or pin p³ and also one end of the arm t2 rigidly
attached to said pivot pin. In Figures 10 and 11 a retractile spring S has one end
suspended from a rigid point while the other end is attached to the knee of the toggle
joint to keep it retracted and the armature A away from the core of the electro-
magnet when said electro-magnet is demagnetized. It is important that meins be
provided for overcoming the residual magnetism in the core of the electro-magnet
immediately after being magnetized and the armature attracted, for withdrawing the
arniature to normal position, said means should offer their greatest power when the
armature is against, or close to the poles of the electro-magnet.
I obtain the most uniform result by attaching a spring or weight at or close to the
knee of the toggle. In Figure 12 the resistance R is also utilized as a spring to
bend the arms 2 and 3 of the toggle at their knee. In Figure 13 a weight W is
used either as a resistance or to bend the toggle and retract it. The arm 2
may be
either bent adjacent to its pivot or entirely straight as shown in the detached
detail and in the upper part of Figure 13. In Figure 14 one end of the
armature A is hinged to the iron head M of the electro-magnet and its opposite end

page_text: is in position to be attracted by the opposite end of pole M² a compressed spring S is
placed under the knee of the toggle to bend it and the resistance can be applied to the
body or arm t which is rigidly connected with the arm t².
In Figure 15 the armature A is carried by a lever A2 pivoted to the base of an
adjustable spring S attached to an extension of the toggle can be used as resistance.
The electro-magnet is adjustable by means of the screw e secured to its heel plate
and connected to the post p2 by two jam nuts.
In Figure 16 the armature A is pivoted to one of the poles or core U of the electro-
magnet and is connected at the opposite end with the arm 3 of the toggle while the
arm 2 pivoted to the post p has its opposite end t extended beyond the knee of the
toggle and is connected with the resistance spring S.
In Figure 17 the armature A is suspended as in Figure 10 but the knee joint of
the armn 2 and 3 is connected with the other toggle consisting of the arms t₁ and to,
the latter arm to has one end pivoted to the post p and the opposite, or knee end is
connected with weight W by means of the resistance core R.
In Figure 18 the armature A is suspended as in Figures 10 and 17 but the electro-
magnet is adjustably retained by means of a screw e passing through the heel iron H
with a spring and nut upon said screw, and a bent spring is placed under the toggle T.
In Figure 19 the armature A is hinged to the overhanging pole or heel plate H of
an electro-magnet of which the other pole or core is shown at C, and to one end. of
said armature is attached one end of a multiple toggle T, the opposite end of which
is retained by a post p and the resistance R can be applied. to either one of the knees
or arms of said. toggle.
In Figure 20 the armature A is carried by a lever A2 pivoted at a to a post secured
to the base B. The upper end of the lever A2 is united by means of connecting rod r
with a lever L pivoted at 7 to a post P and one end of said lever is connected to the
arm 3 of the toggle, its arm 2 being pivoted to the post p and the resistance R is
applied to said arm 2 and by these means said resistance is indirectly transmitted
from the toggle to the armature.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed, I declare that what I claim is :—
1. The combination of a wheel having on its periphery a series of notches at
irregular intervals, a lever 6 having one end pivoted upon the shaft of said wheel, a
pawl pivoted upon said lever and having one end adapted to engage with the notches
of said wheel and the opposite end provided with a T-shaped head, the adjustable stop
pins adapted to engage alternately with the arms of said heads, with a lever F
connected to the lever 6, a lever A2 and means to actuate the said lever A², sub-
stantially as described.
.
2. The combination of the wheel having upon its periphery a series of notches at
irregular intervals and teeth of different widths a nearly counterbalancing retaining
pawl, a pivoted lever 6, a pawl pivoted upon said lever and stop-pins to react upon
said pawls with a pivoted lever A2 and means to actuate said lever A2, substantially as
set forth.
3. The combination of a wheel having on its periphery a series of notches at
irregular intervals, a pivoted lever 6, a pawl upon said lever and stop pins to react
upon said pawl, a coiled spring wound upon the shaft of the wheel to propel it in one
direction and forming a part of an electric circuit, a contact pin upon said wheel and
a spring finger adapted to close the electric circuit by contact with said pin,
substantially as and for the purpose described.
4. The combination of a wheel having on its periphery a series of notebes at
irregular intervals, a pivoted lever 6, a pawl upon said lever, a coiled spring wound
upon the shaft of the wheel to propel it in one direction, a pivoted lever F connected
with the lever 6, a dash-pot piston rod at one end of the lever F, a disc upon said rod
and a dash-pot to receive said rod and disc with a lever A2 bearing against the opposite
end of the lever F and means to actuate said lever A2, substantially as set forth.
5. The combination of a wheel having upon its periphery a series of notches at

page_text: irregular intervals and teeth of different widths, a pivoted lever 6, a pawl upon said
lever, a coiled spring wound upon the shaft of the wheel to propel it in one direction,
a pivoted lever F connected with the lever 6. a dash-pot, a piston rod connected to
one end of the lever F and entering said dash-pot, a perforated movable piston and a
stationary disc upon said rod, substantially as and for the purpose describe:l.
6. The combination of an electric circuit, a wheel its shaft, and a coiled spring,
said wheel shaft and spring forming part of said circuit and the wheel carrying a
contact to actuate said circuit, and a stationary metallic connection in the path of said
contact, whereby the contact forming a part of said wheel is adapted to close the circuit
substantially as and for the purpose described.
7. The combination of a disc 4 having upon its periphery a series of notches at
regular intervals, a disc 5 baving notches at irregular intervals, a lever 6 having one
end pivoted upon the shafts of said discs, a pawl pivoted upon said lever, and having
one end adapted to engage with the notches on the disc 4, and adjustable stop-pins
adapied to engage with the arms on the T-shaped head of the pawl with the pivoted
lever F and its connecting rod, substantially as described.
8. The combination of a disc 4 having on its periphery a series of notches at regular
intervals, a disc 5 having notches at irregular intervals, a lever 6 having one end
pivoted upon the shaft of the discs, a pawl carried by said lever, a pivoted lever F
connected to the lever 6, a lever A², an armature and electro-magnet, substantially as
described.
9. The combination of a disc 4 having upon its periphery a series of notches at
regular intervals, a disc 5 having notches at irregular intervals, a friction wheel H
connected with the notched discs, a pivoted lever 6 and disc-propelling pawl and a
retaining pawl, substantially as and for the purpose described.
1
10. The combination of a disc having upon its periphery a series of notches at
irregular intervals and a slot in its side, a disc 5 having a pin passing through said
slot, a friction wheel connected with the notched discs, a spring bearing against said
wheel, a retaining pawl, a pivoted lever and a disc-propelling pawl, a pivoted lever F
and means for operating said lever substantially as described.
11. The combination of a disc having upon its periphery a series of notches at
regular intervals, a coiled spring wound upon its shaft to propel it in one direction, a
disc having notches at irregular intervals, a retaining pawl to engage with said notches,
a propelling pawl and lever 6 with the lever F connected to the lever 6, and means to
actuate the lever F, substantially as described.
12. The combination of a disc 'having upon its periphery a series of notches at
regular intervals, a coiled spring wound upon its shaft, a disc having notches at
irregular intervals, a retaining pawl, a propelling pawl and lever 6, a pivoted lever F
connected with the pawl lever 6, a dash-pot, a piston rod connected to one end of the
lever F and entering said dash-pot, and a piston, substantially as and for the purpose
described.
13. The combination of an electric circuit, a disc forming part of said circuit and
having a series of notches at regular intervals, a contact upon said disc to actuate said
circuit and a stationary metallic connection in the path of said contact, a spring upon
the shaft of said disc with a disc having notches at irregular intervals and means to
actuate and retain the discs, substantially as described.
14. The combination of two wheels having teeth and notches in their periphery,
the teeth upon a wheel being arranged to close the notches upon the other wheel, a
spring acting upon one of said wheels and a propelling and retaining pawl, whereby
the wheels are propelled and retained, or not retained, according to the relative
positions of the teeth and notches on the two wheels permitting, or not permitting the
pawl to enter the notches, substantially as described.
15. The combination in a circuit-controlling apparatus of an electro-magnet and a
toggle with an armature having one end hinged to one pole of said electro-magnet and
the other end connected to said toggle, substantially as and for the purpose set forth.
16. In a circuit-controlling apparatus an electro-magnet and a pivoted armature, in

page_text: combination with a pair of toggle links, one of which is pivoted at its free end to said
armature and a body fixed to the other link and adapted to rotate therewith.
17. In a circuit-controlling apparatus the combination of an electro-magnet, its
armature hinged to one pole of said electro-magnet, a toggle connected with said
armature and a spring connected with said toggle, substantially as and for the purpose
described.
Deted this 34th dov 1900
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.