Improvements in Secondary Time-maicators.
Year: 1897

page_text: Improvements in Secondary Time-maicators.
I, SAMUEL POWERS THRASHER, of New Haven, Connecticut, United States of
America, Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to time-indicators in which the time is indicated by
numerals visible through an opening or openings in the face or front of the casing
of the apparatus, the numerals being changed as and when required by the step-
by-step rotation of wheels or drums. And my said invention is chiefly designed
to provide for the operation of the said time-indicators by means of electrical
apparatus controlled by a master time-movement or clock.
According to one method I arrange an electro-magnet and armature-lever in
combination with means for in parting step-by-step rotation to the said wheels
or drums in such manner that when the armature-lever is attracted by the magnet,
energy previously stored will be utilized for actuating the said wheels or drums,
and more energy will be stored to be subsequently utilized for actuating the said
wheels or drums.
According to another method I provide the armature-lever with a weight or
spring and with a pawl that engages with a ratchet-wheel on an arbor carrying
a cam or cams for gradually storing energy and then permitting its utilization
for turning the said wheels or drums.
To prevent the transmission of the sudden or rapid motion of the armature
to the said wheels or drums, I so construct the apparatus, according to one method,
that the said armature-lever, when attracted by the electro-magnet, will release a
weighted pivoted frame or yoke, which will then act under the influence of gravity
to rotate the said drums through the required distance, the energy required for
afterwards returning the said frame or yoke to its original position being stored
by the lifting of the armature and of a weighted lever or spring combined there-
with, and being utilized on the release of the said armature-lever.
My said invention also comprises an improved device for completing and
interrupting the electric circuit, which device comprises a toothed or stepped
cam made partly of metal and partly of insulating material and arranged to be
rotated by the master-clock or controlling movement, and a spring or other suitable
contact-finger which bears against the insulating part of the said cam and, in the
rotation of the said cam, will press against one or more points where momentary
contact between the said finger and the metal part of the cam is permitted.
I find it advantageous to employ three of the said wheels or drums carrying the
figures indicating the time, one for the hours, and two for the minutes, and to mount
them loosely on a common shaft, on which is also mounted an oscillating frame
or yoke for imparting step-by-step rotation to the drums. This frame or yoke
carries pawls which are independently mounted therein, and are adapted to engage
with the said drums respectively. Retaining pawls are also provided for prevent-

page_text: ing motion of the drums during the inoperative half or part of the travel of the
oscillating frame or yoke.
The said frame or yoke is weighted or is provided with a spiral or other suitable
spring, so that, when displaced and released by the electro-magnet, it will move
back by gravity with sufficient force to operate one or more of the drums above
mentioned. The said frame or yoke is connected by a rod or link to a pivoted
weighted lever so that the latter can be moved upward without raising the rod or
link, but, in its downward movement, will pull down the said rod or link and
thereby displace the oscillating frame or yoke. The said weighted lever is aranged
to be raised by the armature-lever to release the said rod or link and allow the
said frame or yoke to be moved back by gravity. Suitable stops are, moreover,
provided for limiting the travel of the parts.
To equalize the movement of the armature-lever notwithstanding the variation
in the pull of the electro-magnet on its armature throughout the travel of the
same, the said armature-lever is made curved or cam-shaped where it acts on the
said pivoted weighted lever, the form of the curve being such that the leverage
decreases as the armature approaches the magnet. The said pivoted lever is also
provided with a step or extension on which the end of the armature-lever rests
when released by the magnet and which thus limits the downward movement of
the said armature-lever.
For indicating seconds or other fractions of a minute, I sometimes provide
a graduated semi-circular dial, and a double pointer or double-ended pointer, the
two pointers being mounted on a suitable arbor of the time-indicator and arranged
to pass successively over the graduated arc.
In another form or modification of my apparatus, I arrange the aforesaid contact-
cam to rotate once each minute, and provide it with a number of teeth and contact-
points corresponding to the number of parts into which the minute is to be divided.
The armature of the electro-magnet is mounted on a spring-controlled arm
provided with a pawl which is adapted to act on a ratchet-wheel having, say,
double the number of teeth on the contact-cam, so that it will be rotated once
every two minutes. On the arbor carrying this ratchet-wheel are mounted two
pointers or a double-ended pointer adapted to move successively over a suitably
graduated arc of 180°, and two cams which act on a pivoted lever of the drum-gear
once each minute.
The battery and master-clock can be arranged in any suitable position so as to
control the operation of one or more of my time-indicators from any desired
distance.
It is obvious that the construction of my improved apparatus can be somewhat
modified without departing from the nature of my said invention, for example,
pneumatic or mechanical devices may be substituted for the electro-magnet above
referred to.

page_text: manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:―
My invention relates to time-indicators of the kind or class in which the time
is indicated by numerals visible through an opening or openings in the face or
front of the casing of the apparatus, the said numerals being changed as and when
required by the step-by-step rotation of wheels or drums. And my said invention
is chiefly designed to provide for the intermittent rotation of the said wheels or
drums by energy stored by the aid of electricity, the action of the electrical
apparatus being controlled by a master time-movement or clock.
According to one arrangement an electro-magnet and armature-lever are com-
bined with means for imparting step-by-step rotation to the said wheels or drums,
in such a manner that, when the armature-lever is attracted by the magnet, energy
previously stored will be utilized for actuating the said wheels or drums, and more
energy will be stored to be subsequently utilized for actuating the said wheels
or drums.
According to another arrangement the armature-lever is provided with a weight
or spring and with a pawl that engages with a ratchet-wheel on an arbor carrying
a cam or cams for gradually storing energy and then permitting its utilization
for turning the said wheels or drums.
To prevent the transmission of the sudden or rapid motion of the armature to
the said wheels or drums, I so construct the apparatus, according to one method,
that the said armature-lever, when attracted by the electro-magnet, will release a
weighted pivoted frame or yoke provided with separately mounted pawls, which
frame or yoke will then act under the influence of gravity to rotate the said drums
through the required distance, the energy required for again raising the weighted
end of the said frame or yoke being stored by the lifting of the armature and of a
weighted lever or spring combined therewith, and being utilized on the release of
the same armature-lever.
My said invention also comprises an improved device for completing and
interrupting the electric circuit, which device comprises a toothed or stepped cam
made partly of metal and partly of insulating material, and arranged to be
rotated by the master-clock or controlling movement, and a spring or other suitable
contact-arm or finger, which bears against the insulating part of the said cam
and, in the rotation of the said cam, will press against one or more points where
momentary contact between the said finger and the metal part of the cam is
permitted. The device is so constructed that, when the contact-finger bears against
the conducting part or parts of the said cam, it will, by its pressure against the same,
tend to accelerate the motion of the escapement.
In the accompanying drawings, I have shown how my said invention may be
conveniently and advantageously carried into practice.
Figure 1 is a front view of one form of my electrical secondary time-indicator,
the top part of the case being removed and a portion of its base broken away to
show the electric battery and master-clock within the same.
Figure 2 is a side view, the end of the base being broken away.
Figure 3 is an enlarged sectional view showing a portion of the front end of
the centre arbor of the time-movement extending through the front plate thereof
and having mounted thereon an insulated contact-arm.
Figure 4 is an enlarged view of an insulated binding post secured to the front
plate of the time-movement.
Figure 5 is a face view, and
Figure 6 is a side view, both drawn to an enlarged scale, showing a contact-
arm attached to the seconds-arbor and adapted to operate in conjunction with
the aforesaid contact-arm.
Figure 7 is a top view of the drums bearing the numerals to indicate the time
of day, and showing the perforations in their rims and the arrangement of their
engaging-pawls.

page_text: Figure 8 is an enlarged perspective view of the drums and pawls shown in
Figure 7.
Figure 9 is a top view of the armature of the electro-magnet detached.
Figure 10 is a perspective view of part of the operating mechanism, drawn to
an enlarged scale, showing details of construction.
Figure 11 is a front view showing another form of modification of my electrical
secondary time-indicator.
Figure 11 shows a portion of Figure 11 drawn to an enlarged scale.
Figure 12 is a side view of the same.
Figure 13 is a front view of a contact-cam and a contact-arm operating in 1
conjunction therewith.
Figure 14 is a section of the device shown in Figure 13, with the addition of
one of the plates of the time-movement or master-clock to which the said device
is attached.
In the arrangement of my time-indicator shown in Figures 1 to 10, the base A
contains an electric battery B and a master-clock C adapted to complete and
interrupt the electric circuit once in each minute. An electro-magnet I) is
included in the battery-circuit, whereby energy is stored as hereinafter described
to be subsequently utilized for intermittently rotating the drums L, L', L³, which
are mounted loosely upon a common shaft V. The armature_y is attached at y¹
to a lever Y, pivoted at y², the curved part Z of the lever Y bears against the
underside of a lever a pivoted at a³; and the free end of the said lever Y normally
rests on a step c of the pivoted lever a. Therefore, when the armature-lever Y
is drawn upward by the magnet, it will lift the said lever a, and, when the said
armature-lever is released, it will act upon the step c so as to pull down the
lever a.
An adjustable stop is provided to limit the motion of the lever a.
An oscillating frame or yoke X is mounted upon the same axis as the
drums L, L1, L2, and is provided with three shafts j, j', je on which are mounted
carrying-pawls, f, f, f2 to engage in perforations in the said drums for the purpose
of rotating the same. The said yoke is also provided with count-dogs h h¹ on the
pawl-shafts, to control the action of the pawls f1, f2, as described in the
Specification filed in respect of my Application for Letters Patent dated 30th April
1897, No. 10770. The said yoke or pawl-carrier is, moreover, provided with
a heavy bar or weight R, which may however be replaced by a spiral or other
suitable spring to render the said frame or yoke independent of gravity.
The weight of the lever or gravity bars Y and a are utilized for drawing back
the yoke or pawl-carrier X through the medium of a rod or link e.
After the said yoke or pawl-carrier has been moved back by the weight of the
levers or gravity-bars Y and a as above described, It will be moved forward by the
said weight or its equivalent so as to partially rotate one or more of the drums L,
L', L' through the medium of the pawls f, f¹, få.
Retaining pawls m¹ are also provided mounted on shafts M., for preventing
motion of the drums during the inoperative half or part of the travel of the
oscillating frame or yoke.
In order to prevent undue motion of the wheels or drums L, L1, L2, by reason of
their inertia, when set in motion by the pawls f, f, f, I provide the said pawls
with springs m on their upper or outer sides. These springs, when the yoke X
approaches the limit of its motion in feeding forward the wheels or drums L, L¹, L²
through the required angle, are adapted to pass under a fixed check-bar M and
hold the inclined ends of the pawls f, f, f in the perforations or recesses in the
said wheels or drums, thus preventing undue motion of the same, and at the same
time, by reason of their elasticity, allowing the pawls to be drawn backward on
the return movement of the yoke X. This arrangement also permits of the wheels
or drums being adjusted or "set" at any moment. The check-bar M, in the

page_text: arrangement shown in Figure 8, also serves as the shaft for bearing the idle or
retaining pawl of the hour drum.
The connection between the lever a and the rod or link e is made through an
arm & in such a manner that the said lever a when moved upward suddenly by
the electro-magnet will not move the said rod or link upward, but will leave
the same free to be raised by the movement of the weighted yoke X. The trans-
mission of any sudden or rapid motion from the armature-lever Y to the drums is
thus prevented. The armature-lever Y and the lever are so arranged in com-
bination with each other that, as the armature approaches the magnet and the
pull upon it becomes stronger, the leverage will be diminished, the said armature-
lever first acting upon the lever a at or near its free end and the point of contact
or pressure between them gradually receding from the pivot of the armature-
lever Y and approaching the pivot of the lever a as the armature-lever rises.
As a means of closing and interrupting the electric circuit, I provide a contact-
cam E fixed on the seconds-arbor of the master-clock C and provided with a piece K
of insulating material against which bears a pin G fixed in an arm F
mounted on, but insulated from an arbor J. The said cam is connected with
one pole of the battery B through the time-movement C, the arm F being connected
with the other pole thereof through the terminal H. The insulating material K
on the cam E is cut away at the point I so that contact will be made at this point
in each revolution of the said cam, which rotates in the direction indicated by the
arrow in Figure 5. The point I is on a steep incline so that the pin G, in passing
over it in its descent to the lower part of the cam, tends to accelerate or assist the
movement of the escapement and thus obviate any liability of the clock stopping
while the circuit is closed
It will be seen that, each time the electric circuit is completed, the levers or
gravity bars Y, a will be raised, thus releasing the rod e and permitting the
yoke or pawl-carrier X to move forward and rotate one or more of the drums one
step as required. As soon as the circuit is interrupted, the said levers descend
and draw back the said yoke or pawl-carrier, which is thus caused to oscillate
at regular intervals.
In the modification of my invention shown in Figures 11 to 14, the armature-
lever is pivoted at Y¹, and its short arm is acted upon by a retracting spring U;
to the long arm of the said armature-lever Y is pivoted a spring pawl T which
engages with a ratchet-wheel O fixed on a shaft N, on which is also fixed a double
cam P, and a double-ended pointer Q. The rod or link e is coupled at its lower
end to the long arm of a pivoted bent lever a¹, the short arm of which is provided
with a pin or stud a2 that 'bears against the cam P. The double-ended pointer Q
indicates the fractions of a minute on a graduated arc as described in the Specifica-
tion of my Application for Letters Patent dated 30th April No. 10770. In the
present instance, however, the ratchet-wheel O is provided with 24 teeth and,
at each upward movement of the armature-lever Y when released by the magnet D,
one end of the pointer Q will be moved through a space representing five seconds
on the graduated arc, the cam P at the same time imparting to the actuating
lever a¹ a movement equal to one twelfth of its throw, and a like movement to
the yoke or pawl-carrier X for actuating the time-drums. As shown in Figures 13
and 14, a contact-wheel E is employed having twelve teeth, each insulated from
the pin G of the arm F except at a single point I arranged as above described
so that the pressure of the pin G thereon will tend to accelerate the motion of the
escapement. This contact-wheel E is fixed on the seconds-arbor of the master-clock
so that contact will be made twelve times in each minute. By this arrangement
the magnet exerts its force twelve times each minute, and accordingly a much
larger time-indicating mechanism can be driven thereby. This construction,
moreover, obviates the necessity of employing the usual number of graduation-
marks, and the movement of the pointer traversing the dial can be more distinctly
seen at a distance than heretofore. By varying the number of teeth on the said
ratchet-wheel O, the intermittently-rotated pointer Q may be made to indicate,

page_text: by each succesive movement, other fractions or a minute greater or less than five
seconds.
It is evident that various changes in the construction and relative arrangement
of the parts herein shown and described might be made without departing from
the nature of my said invention.
The battery B and master-clock C can be arranged in any other suitable position
80 as to control the operation of one or more of my time-indicators from any
distance.
I can, if desired, apply the improvements above described to time-indicators in
which the numerals are marked upon endless bands or ribons passed around the
intermittently rotated wheels or drums, as described in the Specification filed in
respect of my application for Letters Patent dated 30th April 1897, No. 10776.
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. A secondary time-indicator of the kind or class herein before referred to,
wherein suitable provision is made for utilizing electrical energy, either directly or
indirectly, for causing the oscillation at regular intervals of a frame or yoke
mounted on the same axis as the wheels or drums and provided with separately
mounted pawls for imparting the required step-by-step rotation to the said wheels
or drums, for the purposes above specified.
2. In a secondary time-indicator of the kind or class hereinbefore referred to,
an electro-magnet included in an electric circuit arranged to be completed and
interrupted at regular intervals, and having its armature fixed upon a lever
adapted to draw back a weighted oscillating yoke or pawl-carrier or to store energy,
for subsequently drawing back the said yoke or pawl-carrier, substantially as
hereinbefore described and for the purposes specified.
3. The combination, with the weighted oscillating yoke or pawl-carrier mounted
on the same axis as the wheels or drums, of weighted levers or gravity bars one
of which serves as the armature-lever of an electro-magnet and, when attracted
thereby, raises the other bar, the energy thus stored in the said levers or bars
being utilized, when the electric circuit is interrupted, to draw back the said yoke
or pawl-carrier, substantially as, and for the purposes, hereinbefore described.
4. The weighted lever or gravity bar adapted to pull down the rod or link
depending from the weighted oscillating yoke or pawl-carrier and provided with
the short arm or step engaging with the armature-lever, substantially as, and for
the purposes above specified.
5. The combination, with the wheels or drums, of the pawls mounted on separate
shafts in the weighted oscillated frame or yoke and provided with springs adapted
to bear against a stationary check-bar and thus hold the pawls in engagement with
the drums and check the forward motion of the same without interfering with
the return movement of the said yoke or the setting of the said drums, substan-
tially as described.
6. The improved device for momentarily closing or completing the electric
circuit at regular intervals, comprising a contact wheel or cam having one or
more projections or teeth and mounted on one of the arbors of a master time-
movement and provided with insulating material so combined with the conducting
material that the contact-pin, when bearing against the conducting part or parts,
will by its pressure thereon tend to accelerate or assist the motion of the escapement,
substantially as described.
7. A secondary time-indicator of the kind or class hereinbefore referred to, where-
in the armature-lever of an electro-magnet is adapted to impart step-by-step rotation
to a cam for actuating a lever to draw back a weighted oscillating yoke or pawl-
carrier, substantially as, and for the purposes, herein before described.
8. The combination of the graduated are and the intermittently rotated double-

page_text: ended pointer adapted to indicate thereon fractions of a minute greater than one
second, substantially as described.
9. The improved secondary time-indicator constructed substantially as described
with reference to Figures 1 to 10 or with reference to Figures 11 to 14 of the
drawings and operating as above specified.
1300
D. YOUNG & Co.,
11 & 12, Southampton Buildings, London, W.C.,
Agents for the Applicant.