IMPROVEMENTS IN ELECTRICALLY-ACTUATED INDICATORS, AND IN TRANS- MITTERS FOR CONTROLLING THE OPERATION OF THE SAME
Year: 1881

page_text: LETTERS PATENT to John Clayton Mewburu, of 169, Fleet Street, in the City
(*
of London, Patent Agent and Consulting Engineer, for an Invention of
'IMPROVEMENTS IN ELECTRICALLY-ACTUATED INDICATORS, AND IN TRANS-
MITTERS FOR CONTROLLING THE OPERATION OF THE SAME." A communication
from abroad by Chester Henry Pond, of New York, in the United States of
America, Electrician.
PROVISIONAL SPECIFICATION left by the said John Clayton Mewburn
at the Office of the Commissioners of Patents on the 4th August 1881.
JOHN CLAYTON MEWBURN, of 169, Fleet Street, in the City of London, Patent
Agent and Consulting Engineer. "IMPROVEMENTS IN ELECTRICALLY-ACTUATED
INDICATORS, AND IN TRANSMITTERS FOR CONTROLLING THE OPERATION OF THE
SAME." A communication from abroad by Chester Henry Pond, of New York, in
the United States of America, Electrician.
This Invention consists principally of certain improvements in the construction
and operation of the electrical indicator, covered by Letters Patent of Great
Britain and Ireland, No. 3505, dated August 28th, 1880, and issued to. William
Clark as a communication from John Van Dussen Reed. It also consists in an
improved transmitter for use in connection with the said indicator, by the use of
which special calls, or wants, or signals may be sent at the will of the operator.
I will first describe the improvements on or applicable to the form or forms of
indicators shown in the first nine Figures of the said Patent. By these improve-
ments I am enabled to dispense with all but one of the actuating electro-magnets,
with all the system switches, with all the correcting switches and electro-magnets
controlling them, with all the locking pins on the indicating wheels, and with a
portion of the restoring mechanism, shown in the said Figures of said Patent. In
addition to these simplifications the present improvements also render an indicator
of two or more indicating systems capable of working in the line circuit, thereby
dispensing with the local battery and relay.

page_text: Instead of rotating the indicating wheels each by means of a cord and weight, I
now fix a pinion to the hub thereof, and arrange a vertical cog-rack to mesh
therewith, whose weight is sufficient to rotate the wheel with the requisite speed.
This enables me to dispense with the second cord, by pulling which the wheel was
rotated backward to its starting point, as it is now only necessary that the rack be
pushed upward to rotate the wheel back. A toothed segment adapted to turn on
a pivot may be used in place of the rack.
The racks of the two or more indicating systems are lifted in restoring the
indicator by the horizontal arm or arms of an elbow lever, fulcrumed at the back
of the case, the vertical arm of which extends downwardly through the case and
bears a handle. By pulling this handle forward all the parts of the indicator are
restored to their normal or starting positions. Its horizontal arms lift also certain
vertically sliding bars, one to each system, which are substituted for the vertically
sliding rods shown in Figures 7 and 8 of the said Patent. Each of these bars
has a projection to take under and lift the escapement rack, and an inclined cam
surface to push back a downwardly extending arm of an elbow lever, whose
backwardly extending and approximately horizontal arm receives the downward
pressure of a spring and is normally upheld by its extremity resting on a shoulder
on the locking lever. When this locking lever is slightly pushed back by the
stoppage of the revolving wheel, its shoulder passes from under the upper arm of
said elbow lever, and the latter is pressed down by its spring, whereupon a roller
on its end rides on an inclined cam surface on the upper arm of the locking lever,
pressing back that arm thereof, and throwing its lower arm forcibly forward
against the periphery of the wheel. This lower arm of the locking lever is faced
with rubber or other frictional material which binds against the wheel and
prevents its rebound. I thus render the locking lever or friction brake, dispense
with the radial locking pins on the wheel, and render it unnecessary to make the
lower arm of the lever elastic. In restoring the apparatus as the elbow lever
returns to its original position, the upper arm of the locking lever is pressed
forward by its spring, and its shoulder again comes under and upholds the elbow
lever. As the lower or restoring elbow lever returns to its normal position the
vertically sliding bars drop, so as to be out of the way of the upper elbow
levers.
Instead of employing a separate electro-magnet for each indicating system, and
switching the circuit from each magnet to the succeeding one, as in the said Patent,
I employ but one magnet for all the indicating systems, and I omit the switches,
providing in their stead means for transferring the action of the magnet from one
system to the next. The magnet is normally in operative connection only with
the first system; when that completes its operation it establishes an operative con-
"nection between the magnet and the second systein, and so on.
The escapement pallets of all the systems are mounted on radial arms or cranks
projecting from a shaft, which shaft is oscillated by the vibrations of the armature
of the magnet, so that all the pallets vibrate simultaneously. This would drop
all the escapement racks together, except that provide means for keeping all the
racks except that of the first system upheld, out of engagement with the pallets,
so that the latter vibrate freely beneath their lowest teeth. When the first system
completes its operation the stoppage of its indicating wheel causes the escapement
rack of the second system to be dropped onto its pallet, so that the subsequent
vibrations of that pallet will drop the rack. The racks are each (except the first)
upheld by a detent which takes under a shoulder on the rack and is retracted by
the backward movement of the locking lever of the preceding system. This detent
is preferably the rod in said Patent, whose end enters under a slight shoulder
on the rack, and is pressed forward by a light spring, the shoulder at its rear end,
which drives back its own locking lever when its indicating wheel stops, is normally
out of contact with said lever, so that when it is pushed back to drop its rack it
does not disturb said lever, and it bears a radial pin or shoulder. As the upper
arm of the locking lever of the preceding system is driven back by the stoppage

page_text: of the wheel thereof, a spring arm projecting laterally therefrom strikes this pin
and so pushes back the rod and causes it to drop its rack.
The dropping of the racks may be accomplished in several other ways than that
just described, and the transfer of the operative connection with the magnet from
one system to the other may be accomplished otherwise than by the successive
dropping of the racks, as for instance but one pallet might be vibrated at a time,
that of the first system being first vibrated, the connection with the armature
being then transferred to that of the second system, and so on.
Instead of the "correcting switches" shown in the said Patent, I use simply an
additional escapement tooth on each of the escapement racks, except that of the
first system. This tooth is a counterpart of the others, and is formed below the
bottom tooth shown in said Patent, and on the opposite side therefrom, being
immediately below the second tooth from the bottom there shown. The rack is
upheld high enough for the pallet to vibrate freely under this tooth. If the rack is
dropped while the circuit is in its normal condition, the pallet is not under this
extra tooth, and this tooth drops past the pallet, the first or lowest working tooth
dropping onto the pallet, whereupon the rack is in its starting position, so that at
the next movement of the pallet it will drop far enough to release its indicating
wheel. But if the rack is dropped when the circuit is in the opposite of its
normal condition, being in the condition pre-arranged to effect the starting of the
system; then the pallet is under the extra tooth and the rack falls only until that
tooth rests on the pallet, and at the return movement of the pallet it drops until
its first working tooth rests on the pallet as before, so that the next movement of
the pallet effects the starting of the indicating wheel..
To prevent any accidental backward movement of the escapement rack when
raised to its normal position, and until it descends to such point as to release the
indicating wheel, I provide it with a shoulder, which contacts with a back stop
until it has descended to the releasing point, when its shoulder clears said
stop.
I will now describe my improved transmitter. In practice I usually arrange
several transmitters in the same circuit with one or more indicators, each
transmitter being designed to transmit a number peculiar to itself, so that the
number displayed at the indicator will show which transmitter has been operated,
and to also transmit any one of a series of special characters or words marked on
the indicating wheel of, for instance, the third system of the indicator, the character
transmitted being determined by the operator. Thus in a hotel my indicator will
be placed in the office and one transmitter will be placed in each room.
When a
transmitter is operated it causes the indicator (to display the number of the room
and also a word or character signifying the want of the guest, as towel," "ice
water," "waiter," etc. The one of the latter characters transmitted depends upon
which of a series of buttons is pressed in by the guest or operator, each button
being marked with the word which it, if pressed in, will cause the indicator to
display. This capability of my indicator renders it also applicable for police
telegraphs, the transmitters being set in boxes at different points on the
policemen's beats, and to district telegraphs or municipal telegraphs, a transmitter
being placed in the residence of each subscriber and the indicator at the central
office.
"
My transmitter includes a circuit closing or circuit breaking key vibrated by a
cam wheel, as shown in Figures 9 to 13 of the said Patent; but in addition to the
two series of cam teeth on the wheels there shown I form also a third series,
consisting of five teeth, so that if the wheel be rotated one complete revolution the
last character of the third system at the indicator will be displayed. To display
any other character the wheel is stopped after the number of teeth of the third
series corresponding to that character have acted on the key, and it is held
stationary long enough for the third system to complete its operation, after which
the cam wheel may complete its revolution. To effect this stoppage of the cam
wheel at different points of its rotation I provide movable stops operated by knobs

page_text: each adapted when its button is pressed in to move back into the path of a
projection or shoulder which is connected to and rotates with the cam wheel, and
each of these stops is so arranged as to intercept and stop the wheel at a different
point or after a different number of movements have been communicated to the
key by the teeth of its third series. Thus, if to display the word "doctor" at the
third system of the indicator requires that the condition of the circuit be changed
from open to closed, or vice versa, four times the intercepting stop operated by the
button marked "doctor" will be arranged at such point as to stop the cam wheel
after but two teeth of its third series have acted on the key and caused it to make
four movements.
Instead of using a cam wheel to vibrate a circuit breaking key I may use a
circuit breaking wheel, or one having notches or insulated spaces formed in its
periphery with a contact spring pressing on its periphery. When the spring
touches the conducting surface of its periphery the current flows from the spring
through the wheel, but when a space or insulation comes under the spring the
circuit is broken in manner well known; or instead of a wheel a pivoted segment
or a sliding rack may be used.
To rotate the wheel I employ a spring or weight wound up by pulling a cord
or lever, as in the said Patent. To transmit a signal the operator presses in one
of the buttons with one finger, and while holding it in pulls the cord or lever with
the other hand, releases it, and in a moment when the mechanism stops running
he releases the button.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Clayton Mewburn in the Great Seal Patent Office on the
2nd February 1882.
JOHN CLAYTON MEWBURN, of 169, Fleet Street, in the City of London, Patent
Agent and Consulting Engineer. "IMPROVEMENTS IN ELECTRICALLY-ACTUATED
INDICATORS, AND IN TRANSMITTERS FOR CONTROLLING THE OPERATION OF THE
SAME." (A communication from abroad by Chester Henry Pond, of New York, in
the United States of America, Electrician.)
This Invention consists principally of certain improvements in the construction
and operation of the electrical indicator invented by the said Chester Henry Pond,
covered by Letters Patent of Great Britain and Ireland, No. 3505, dated
August 28th, 1880, and issued to William Clark as a communication from John
Van Dussen Reed. It also consists in an improved transmitter for use in connection
with the said indicator, by the use of which special calls, or wants, or signals may
be sent at the will of the operator.
I will first describe the improvements on or applicable to the form or forms of
indicators shown in the first 9 Figures of the said Patent. These improvements
dispense with all but one of the actuating electro magnets, with all the system
switches, with all the correcting switches and electro magnets controlling them,
with all the locking pins on the indicating wheels, and with a portion of the
restoring mechanism shown in the said Figures of said Patent. In addition to
these simplifications the present improvements also render an indicator of two or
more indicating systems capable of working in the line circuit, thereby dispensing
with the local battery and relay.
In Figures 1 to 6 of the accompanying Drawings I have shown an indication of
three indicating systems, or one capable of displaying to view three characters (as a
number of three figures) at the same time. Figure 1 is a front elevation partly in
vertical section cut along the dotted lines 1-1 in Figures 2, 3, and 5, and looking
in the direction of the arrows 1 ; Figure 2 is a side elevation of the first indicating
system, being partly in vertical section cut along the lines 2-2 in Figures 1 and 5,
and looking in the direction of arrow 2; Figure 3 is a side elevation of the second
system cut along the lines 3-3 in Figures 1 and 5; Figure 4 is a similar view to
Figure 3 omitting some parts and showing others in a different position; Figure 5
is a plan, partly in horizontal section, cut along the lines 5-5 in Figures 1, 2,
and 3; and Figure 6 is a fragmentary plan on an enlarged scale cut along the
lines 6-6 in Figures 1, 2, and 3.
I will first describe the parts shown in the before mentioned Patent of Clark
which are retained in the present construction.
d is the intermittently moving escapement rack; e, e, are the escapement teeth
thereof; D is the intermittent stop; G is the actuating electro-magnet; F is the
armature thereof; f is the pallet receiving motion from said armature; E is the
escapement as a whole; A is the non-intermittently moving part or character-
bearing wheel; c, c, are the pins or stops thereon; is the aperture in the enclosing
case through which the characters on the wheel A may be seen; I is the locking
lever for the wheel A; i is the rod which moves said lever back; and J is
the drop lever which holds said lever back. Of the resetting or restoring
mechanism M is the vertically sliding rod, and is the arm or toe thereon for
lifting the rack d.
The parts thus far referred to are constructed substantially the same as in the
said Patent of Clark, and are fully described therein, although designated by
different letters. I will now describe the present improvements.

page_text: •
The wheel A is rotated by means of a vertically sliding rack B engaging a
pinion b fixed to the wheel. The weight of the rack gives to the wheel a
continual tendency to revolve in the direction of the arrow in Figure 2. The use
of the rack, obviates the difficulties incident to the stretching and breakage of the
cord before used, and also dispenses with the second cord (lettered in Clark's said
Patent) employed to rotate the wheel backward in restoring the apparatus. This
simplifies the restoring device, a mere elbow lever L having a horizontally projecting
arm L (Figure 3) which takes under the end of the rack B, and which, when its
lower arm, which projects through the bottom of the case, is pulled forward, lifts
the rack and rotates the wheel A. back to its starting point. The part B may be
a pivoted segment instead of a sliding rack, the essentials being that it shall have
teeth to engage the pinion h and sufficient weight to rotate the wheel D.
The lever I instead of having a spring-tail to engage pins on the periphery of
the wheel A is or may be rigid, and its lower arm bears directly against. the
periphery of the wheel, being pressed thereagainst by a spring, and acting as a
friction brake to check the rebound of the wheel when it is stopped. The brake
portion of the lever lettered K is preferably faced with rubber, as shown. The
drop J is in the form of an elbow lever as shown, by preference, and has a toe j¹
which normally rests upon a tooth or ledge j on the lever I. It it pressed down-
ward strongly by a spring or by its own weight. At its end it bears a wheel K,
and on the face of the lever I is formed an incline or wedging surface 1. The
lever I is normally pressed forward by a light spring 1', so that the brake K is
kept clear of the wheel A. When the wheel A is stopped by one of its pins c, c,
striking the stop D, the lower portion of the rack dis tilted backwards, thereby
driving back the rod i, so that a shoulder on its rear end presses back the lever I,
the ledge thereon moves from under the toe j', and the drop J descends. In so
doing its wheel k rolls on the inclined surface 1, and the lever I is pressed still
further back, bringing its brake K forward into firm contact with the wheel A,
and holding the latter in the position in which it was stopped, as shown in
Figure 4. In restoring the parts after their operation, the arm L' of the elbow
lever L takes under the rod M and lifts it, whereupon an incline q on the rod
engages a wheel q' on the downwardly projecting arm J¹ of the lever J, forces said
wheel and arm backward, and thereby lifts the arm J and permits the lever L to
be pressed back to it normal position by its spring I', thereby releasing the
wheel A. This is effected before the arm L' engages the rack B even when the
latter is in its lowest position, indicated in dotted lines in Figure 2, and hence the
wheel A is always unlocked before any attempt is made to rotate it back to place.
The lever J is lifted slightly above its normal position, and when the rod M
descends with the arm L it drops until its toe j' rests on the ledge_j. It is
--obvious-that-this-drop may be modified in several ways without departing from its
essential features. It may, for instance, be a sliding bolt arranged vertically above
the lever I, pressed downward by a helical spring, and having a narrow toe resting
on the upper end of the lever I, and an inclined surface to press back the lever
when it descends.
In the said Patent of Clark there is shown in Figures 1 and 8 thereof an
indicator of two systems, that is, two indicating mechanisms arranged to operate
successively, and each capable of displaying one character or number. I have here
shown an indicator of three systems capable of displaying a number of three figures.
These systems are lettered S1, S2, and S³ respectively, the system S¹ (Figure 2) at
the right being the first to operate, and the system S2 (Figure 3) being the next
to operate, and the system S³ the last.
Instead of employing a separate magnet G for each indicating system, and
switching the circuit from each magnet to the succeeding one, as in the said Patent
of Clark, but one magnet is now employed for all the indicating systems, and the
switches are entirely dispensed with, means for shifting the action of the magnet
from one system to the next being substituted therefor. Each pallet f is borne on
a radial arm, which is fixed to and vibrated by a rock shaft 8, which shaft is

page_text: connected to the armature F by a link v, Figures 3 and 5. A retracting spring or
weight will be used to normally draw the armature away from the magnet G, and
suitable stops will be provided for limiting the play of the armature and shaft.
This shaft G should be very light and stiff, being preferably made of steel rod.
Each movement of the armature is communicated through the shaft to all the
pallets.
The rack d of the first indicating system (S', Figure 2) is or may be constructed
precisely as shown in the Patent of Clark before referred to, its lowest tooth e
resting normally on its pallet f
To prevent the systems S2 and S3 from operating while the system S' is being
operated, they are thrown out of gear with their pallets by the rack d of each being
lifted slightly, and there sustained so that its bottom tooth e is clear of tho
pallet This permits the pallets to vibrate freely without encountering any
resistance from the racks d of the systems S2 and S3, the pallets of these systems
being then idlers. Thus the vibrations of the armature F and pallets f. ff. first
operate only the system S'. When that system has ceased its operation, the.
rack d of the system S³ is automatically dropped onto its pallet f, and the
subsequent vibrations of the armature and pallets effect the operation of the second
system. When the operation of that is completed, the rack d of the system S³ is
also automatically dropped, thus bringing that system into connection with its
pallet.
The automatic dropping of the rack of one system when the operation of the
preceding system is completed may be accomplished in several ways, the preferable.
one being shown in the Drawing. The rack d of each of the systems S2 and S³ is
provided with a downwardly bearing shoulder n, which preferably rests upon a
detent m.
This detent, which I have shown in the form of a sliding rod, is moved
out from under the shoulder n by the movement of the lever I of the preceding
system. The said lever bears an arm p, preferably a spring arm, which as the
lever moves back strike a projecting pin or shoulder m' on the detent m, thus
pressing back the latter. The detent is normally pressed forward by a very light
springs. I prefer that the rod i and the detent m shall be identical as shown, in
which case I arrange the shoulder i for engaging the lever I to be normally held
out of contact with the lever by the spring S¹. The arm p presses back the
rod m, i, only far enough to clear the shoulder n, and not far enough to force the
shoulder against the lever I, so as to press the latter back. During this first
movement the rod m, i, acts only as the detent m, it then assuming the position to
act as the rod i upon the stoppage of the wheel A. In restoring the apparatus
after use,
the forward movement of the lever I when released forces the rod m, i,
and rack d forward, and when the rack reaches its upperinost position, the
spring & presses the rod m, i, still further forward under the shoulder m.
In order that the backward movement of the arm p may not press back the
rod m, i, so far that its shoulder i forces back the lever I and releases the drop J,
I provide a guard or fixed stop 7', shown in Figures 1 and 6, against which the
arm p will strike when it has moved back far enough.
It is evident that if all the racks & were like that of the system S', then at the
completion of the operation of that system in case the actuating circuit were in the
opposite of its normal condition, or in the condition prearranged to effect the
starting of the systems, the system S² would be at once started without waiting
for the manipulation of the circuit to be resumed, its rack d would fall one tooth,
and the wheel A would be released, and would display its first character and stop,
thus causing an erroneous indication.
In the said Patent of Clark, a correcting switch" is employed to obviate this
difficulty, but in the present construction a novel form of the rack d is employed
instead. Referring to Figures 3 and 4, e¹ is an additional tooth formed on the
rack & beneath the lowest tooth e, and corresponding to the teeth e, e, in form and
arrangement. The rack is normally held up so high by the detent m, or by other
means, that this tooth e' is slightly above the pallet f, as shown in Figure 3, and

page_text: the stop D is prolonged downward sufficiently to restrain the first pin c when it is
thus lifted. I will here assume that the actuating circuit which includes the
magnet G is normally open, its first closure effecting the starting of the apparatus,
this being the method provided for by the arrangement of parts shown in the
Drawings. If the operation of the system S ceases with the circuit open, or in its
normal condition, the rack d of the system S³ will drop until its lowest tooth e
rests upon the pallet, when it is in the position normally occupied by the rack d of
the system S', and when the circuit is again closed the operation of the system S²
will commence. In this case the tooth e! does not come into use. But if on the
contrary the operation of the system S¹ ceases when the circuit is closed, or in the
condition prearranged to effect the starting of the systems, the rack & will drop
only until its tooth e¹ rests upon the pallet; then when the circuit is broken or
brought back to its normal condition, the pallet moves from under said tooth, and
the rack drops until its lowest tooth e rests upon the pallet, it being then in its
starting position, so that the next closure of the circuit will commence the operation
of the system.
"
This means for insuring the correct operation of the indicator is much simpler
and cheaper than the "correcting switch" before employed, and is equally reliable
in its operation. It is as applicable to the construction shown in the said Clark's
Patent, where each pallet is operated by a separate magnet, and the circuit is
shunted from one magnet to another, as to the present construction. In that
Patent the magnet of the succeeding system was kept out of circuit after the
operation of the preceding system until the circuit assumed its normal condition,
while by this improved method the magnet is kept in the circuit and permitted
to operate, but both the act of shifting the operative connection from the preceding
to the succeeding system, and the movement of the pallet as the circuit resumes its
normal condition, are rendered important to commence the operation of the
succeeding system. Other means than that shown may be readily devised to
accomplish this result, and my present means may be applied to insuring the
correct operation of step-by-step or intermittently moving indicators.
In order to prevent any accidental backward movement of the rack a while it is in
its normal position and until it descends to such a point as to release the wheel A, Τ
provide it with a projection x (Figure 3) which abuts against a fixed surface or
shoulder back of it, when the rack is raised or in its normal position, and
passes below said shoulder when the rack falls far enough to release the wheel A.
While the projection is in abutment with the shoulder ¹ the rack d has no
backward play, but when it passes below the shoulder the rack may be driven back
by the impact of the wheel A in stopping.
Instead of making the rack d in two pieces joined together, it is now made in
one piece, and its upper portion is provided with two opposite-laterally-projecting
-ears d',-d', which slide in the vertical guides. When the lower portion of the rack
is driven backward by the impact of the wheel A, the rack tilts on these ears as a
fulcrum, as shown in Figure 4.
It will be understood that the systems S2 and S3 are alike, and that as many
such systems can be arranged in succession as may be desired.
I will now describe the improved transmitting device, referring to Figures 7
to 12. Figure 7 is a front elevation, the enclosing case being partly broken away;
Figure 8 is a vertical section cut along the lines S-8 in Figures 7, 9, and 10, and
Figure 9 is a rear elevation in section cut along the line 9-9 in Figure 8;
Figure 10 is a front elevation in section cut along the line 10-10 in Figure 8,
and Figure 11 is a front elevation of a transmitting-wheel detached; Figure 12
shows the circuit connections between the transmitter and indicator.
In practice I usually arrange several transmitters in the same circuit with one
or more indicators, but two being so shown in Figure 12, each transmitter being
designed both to transmit a number peculiar to itself, so that the number
displayed at the indicator will show which transmitter has been operated, and also
to transmit any one of a series of special characters or words marked on the

page_text: "
indicating wheel of, for instance, the third system of the indicator, the character
transmitted being determined by the operator. Thus in a hotel my indicator will
be placed in the office, and one transmitter will be placed in each room. When a
transmitter is operated it causes the indicator to display the number of the room,
and also a word or character signifying the want of the guest, as towel," "ice
water," "waiter," etc. The one of the latter characters transmitted depends upon
which of the series of buttons is pressed in by the guest or operator, each button
being, marked with the word, which it, if pressed in, will cause the indicator to
display. This capability of this Invention renders it also applicable for police
telegraphs, the transmitters being set in boxes at different points on the policemen's
beats, and to district telegraphs or municipal telegraphs, a transmitter being placed
in the residence of cach subscriber and the indicator at the central office. The
application to a police telegraph is the one shown in the Drawing.
N is a box to be fastened to the wall at the transmitting station, and P, P, are
the buttons referred to. Each button is marked with a number or word (both
being shown in the Drawing). If words are used with the arrangement shown
the wheel A of the system S³ (or in any case the last system), at the indicator
will be marked with the words in the following succession, instead of with the
numerals 0, 1, 2, 3, etc.,="fight," "drunk," "murder," "ambulance," "" doctor,"
riot," “
fire," reinforcements," " telephone." The numbers
marked on the buttons in the Drawing correspond to those on the system S³ in
Figure 5. To send a signal, the operator at any station first presses in the knob
P, which bears the number or word which he wishes to send and holds it in, he
then pulls down a cord O and releases it, and he then releases the knob P.
"
burglary,"
"
15
Qis a circuit closing spring or key, Q' is a contact point or spring against
which it works, and R is a cam wheel having teeth r, r, which as the wheel
revolves engage the end of the spring Q and vibrate it. The wheel R is rotated
by clockwork in the direction of the arrow 13, and turns one revolution every
time the cord O is pulled. S is a spindle, on which is fixed the wheel R and also
an escapement wheel T, whose teeth engage a vibrating pallet f. U is a windlass
barrel which is loose on the spindle S, and has a tooth won its periphery, which
is engaged by a pawls on the wheel T. The cord O winds on the barrel U. As
the cord is pulled it unwinds from the barrel and rotates it in the direction of the
arrow 14 in Fig. 9, thus winding up the spring V. As the barrel turns the
tooth w leaves the pawl s, and when one revolution is completed it comes under it
again and the pawl 8 drops back to place. Then when the cord is released the
spring V rotates the barrel in the opposite direction (see arrow 13, Figures 7, 9,
and 10), thus winding up the cord O, and by the tooth w pushing against the
pawl 8, rotating the wheel T, spindle S, and cam wheel R one revolution.
The cam wheel R has three series of teeth 1, 2, and ³, corresponding to the
3 indicating systems of the indicator. Each side of each tooth corresponds to
one of the teeth e, e, and to one of the characters on the wheels A, A. The first
two series of teeth 1, in Figure 7 will cause the number "51" to be displayed
at the indicator. The teeth and 2 in Figure 11 will cause "72" to be displayed
at the indicator.
The space between the first two series of teeth in Figure 7 and the long tooth
in Figure 11, one to give time for the wheel A of the system S¹ to stop. The side
t of the long tooth in Figure 11 corresponds to the escapement tooth e' of the
indicating system S2. The third series of teeth 3 consists of 5 teeth which are
sufficient to cause the last character ("telephone") of the system S³ to be displayed.
The knobs P, P, are to cause some preceding character to be displayed by preventing
more or less of the teeth from acting upon the spring Q until after the system $³
has operated and stopped. P¹, P¹ are a series of springs, one to each knob P, each
of which (except P¹ "9") bears a lug or tooth u. The wheel T has three lugs or
teeth v, v1, v2, each of which moves in a different path, as shown by the dotted
circles in Figure 10. When either spring P¹ is pressed back by pushing in its
knob Pits tooth u moves into the path of one of the teeth v, v², or v², and when

page_text: that tooth strikes it the wheels T and R are stopped.
Each knob P is adapted
to stop the wheel at a different point in their revolution, so that the use of each
causes a. different number of teeth to act on the springs Q. Thus the knob
"P"1" ("drunk ") stops the wheel R with the end of the spring Q in the space
between the first and second teeth 3, thus closing and breaking the circuit once
and causing the word "drunk to be displayed at the indicator, and the knob
P "4" ("doctor") stops the wheel R with the end of the spring Q on the third
tooththus closing, breaking, closing, breaking, and closing the circuit, and
causing "doctor" to be displayed at the indicator.
Other mechanism than that shown may be employed to rotate the wheel R, and
other means may be used to stop the wheel after more or less teeth have acted
on the spring Q. The wheel R may have a smooth edge against which the spring
Qpresses, the portions corresponding to the spaces between the teeth r, r, being
insulated, and the wheel and spring both being in the circuit, or a sliding rack
may be substituted for the wheel.
The use of my transmitter and indicator renders it possible to send a signal with
great rapidity and certainty, and no skill is required to send it or understand it.
For fire alarms the improved transmitter here shown will not be used, that shown
in the said Patent of Clark being employed instead, as for that purpose it is not
desired that any signal be transmitted except the number of the signal box.
I have shown the transmitter and indicator as adapted to operate with a
normally-open circuit, but this is not essential, as they may with slight alteration
be arranged in connection with a normally closed circuit.
Having thus fully described and ascertained the nature of the said Invention of
the said Chester Henry Pond, I declare that what I claim thereon and desire to
secure by Letters Patent is as follows:-
First. The improved means, as herein before described, for rotating the wheel A.
Second. The employment of a friction brake K to prevent the rebound of the
wheel A, with means for pressing it against the wheel upon the stoppage of the
latter, substantially as set forth.
Third. The combination with the wheel A and stop D of a rod i, lever I, bearing
brake K, drop J, upheld by said lever, and a suitable wedging incline, whereby
the fall of the drop operates to press the brake against the wheel, substantially as
described.
Fourth. The improved restoring device for the several parts, all operated by the
movement of a single lever to set the apparatus back to its position of starting,
substantially as described and shown.
Fifth. Operating an indicator of two or more indicating systems from a single
electro magnet by means substantially as shown and described.
Sixth. The combination of a first indicating system, consisting of a non-
intermittently moving part or wheel A, and an escapement for controlling the
extent of its motion with a second like indicating system, with an electro magnet
normally in operative connection with the escapement of the first system, and with
means for connecting said magnet with the escapement of the second system upon
the completion of the operation of the first system, substantially as shown and
described.
Seventh. The means described for preventing the premature starting of the
second system upon the completion of the operation of the first system, the same
consisting of the extra escapement tooth e, arranged and adapted to operate
substantially as set forth.
Eighth. The combination in an indicator of the escapement rack d, having a
projecting portion x with a fixed bearing surface or shoulder a¹ to prevent any
premature backward movement of the rack, arranged and adapted to operate
substantially as set forth.
Ninth. The automatic transmitter shown and described, consisting of a circuit
manipulating device constructed to transmit when operated a number peculiar to
itself, and also to effect an additional series of circuit manipulations representing

page_text: the last of a series of characters, and having means under the control of the
operator for checking its operation upon the completion of any number of circuit
manipulations of said series corresponding to any previous character of said series,
substantially as described.
Tenth. The combination in said transmitter of the clockwork, the cam wheel,
the key, the series of buttons, and the series of stops connected therewith, all
arranged and adapted to operate substantially as set forth, whereby the pressing in
by the operator of any button will effect the stopping of the apparatus when it has
effected the number of circuit manipulations corresponding to said button.
In witness whereof, I, the said John Clayton Mewburn, have hereunto set my
hand and affixed my seal, this Twentieth day of January, in the year of
our Lord eighteen hundred and eighty two.
J. C. MEWBURN. (LS.)