Year: 1896

page_text: MAUNSELL MERCIER 5 Deansgate Manchester Electrical Engineer, do hereby
declare the nature of this invention to be as follows:-
My invention has for its object the improvement of apparatus for electrical
signalling by which the number of signals can be seen as well as beard. Numerous
accidents have occurred in coal mines and other places through the engineman
mistaking the count of the signals given.
My invention is so arranged that where the electric current is used as a means
of transmitting signals from one place to another I use an indicator actuated by
the electric current which indicator clearly shows the number of signals sent.
Where an electric bell or sounder of any sort is used my indicator can be used in
conjunction with the same or my indicator may be used by itself if so desired.
The electric current may be arranged to actuate my indicator in various ways
where single stroke or tremulous electric bells are used for giving audible evidence
cf the signals sent. The current may be used to work my indicator in series or in
parallel with the bell, or my indicator may be worked by a relay and local battery.
I so arrange that the electric current is passed round an electric magnet which
attracts an armature which has attached to it a lever with a tooth at the end,
which engages with a toothed wheel on the spindle which carries my indicator disc
or finger.
The attraction of the armature moves the spindle and disc or finger through a
distance proportionate to the number of the teeth in the wheel, and if there are
twelve teeth in the wheel, the first signal moves the disc or finger one twelfth of
the circle and indicates one, on breaking circuit the armature is released and is
pulled back by a spring and on the next completion of the circuit it is again
attracted by the magnet and pulls the disc round another segment of the circle and
indicates two, and so on until the maximum number of signals have been given.
On the completion of a signal a certain interval is allowed during which the disc
or finger can automatically return to the zero position to accomplish which 1 arrange
that the spindle has attached to it a chain or string with a weight attached and as
the spindle revolves, it winds up this weight which then has a tendency to turn the
spindle back again to zero. This return movement is prevented by a pawl engaging
in the teeth of the wheel which prevents the return until the pawl is released.
The armature has a lever attached which is connected to a dash pot suitably
arranged to retard its movement on the release stroke and this lever is so arranged
that at the expiration of any suitable interval it automatically releases the pawl
and allows the action of the weight to return the disc or finger to the zero
position.
The action of the dash pot does not in any way prevent the armature lever
immediately releasing and so engaging another tooth for the forward movement of
the disc or spindle but the action of the dash pot so provides that after the com-
pletion of the signal the disc or finger shall remain in position for a definite fixed
period before returning to the zero position. I also arrange that the pawl may be.

page_text: instantaneously released and the disc or finger set back to the zero position by the
action of an electro magnet worked by suitable means such as the pressing of a
button or key which may be done by hand or by the movement of the machinery
or otherwise as may be arranged.
Dated this 13th day of Anil 100
Electric Signal Indicator.
I, MAUNSELL MERCIER of 5 Deansgate, Manchester, in the County of Lancaster,
Electrical Engineer do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
My invention has for its object the improvement of apparatus for electric
signalling by which the number of signals transmitted can be seen as well as heard.
Numerous accidents have occurred in coal mines and other places through the
engineman mis-counting the number of audible signals given.
My invention is so arranged that where the electric current is used as a means
of transmitting signals from one place to another I use an indicator actuated by
the electric current, the said indicator clearly showing the number of signals sent.
Where an electric bell or sounder of any sort is used, my indicator can be used in
conjunction with the same or my indicator may be used by itself if so desired.
The electric current used to actuate the said bell or sounder so as to give audible
evidence of the signals sent is also caused to actuate my said indicator. The
current may be used to work my indicator in series or in parallel with the bell or
it may be worked by a relay and local battery.
In order that my invention may be better understood and the more readily
carried into effect I have hereunto annexed a sheet of drawings wherein Fig. 1 is a
partially sectional side elevation of my apparatus with the back frame removed
the dial and indicating finger being shown in dotted lines to indicate their relative
position and Fig. 2 is an end elevation.
I so arrange that the electric current by which the audible signal is transmitted
is passed round an electric magnet A so as to attract an armature B to which is
hinged a lever C. The lever C has hinged to it an arm C¹ formed as a pawl
(hereinafter called the operating pawl) which engages with a ratchet wheel D
fixed on the spindle E ou which is also fastened either the indicator disc F¹ or
finger F. On the face of the disc are fastened, painted or in some other way
attached, consecutive numbers 1, 2, 3, 4, and so on. When the finger F is fixed
on the spindle the disc F is fastened to the framing so that each movement of the
spindle by the action of the pawl causes the finger to move over the face of the dial
a distance equal to the space from one number to the next so that its point is
opposite the figure indicating the number of the signal. I may fasten the disc F
to the spindle and fix the finger to the framing in which case the numbers are
arranged on the face of the disc successively in the opposite direction to that used
when the disc is fastened to the frame. The disc F¹ is then caused to rotate with
the spindle a distance equal to the space between the figures. 1 may dispense
entirely with the finger F and use instead a plate covering the disc with an aperture
at one point so that cach number can be seen as it is successively brought into the
required position by the action of the operating pawl. The attraction of the
armature moves the operating pawl and consequently the spindle and disc or finger
through a distance proportionate to the number of the teeth in the ratchet wheel

page_text: the various levers being proportioned to ensure this result. Thus if there are
twenty teeth in the wheel the first signal moves the disc or finger one twentieth of
the circle and indicates one. On the breaking of the circuit the armature is
released and is pulled back by the spring G attached to the lever C and a stud G¹.
On the next completion of the circuit the armature B is again attracted by the
magnet and pulls the disc round another segment of the circle and indicates two
and so on until the desired number of signals have been given.
A certain interval is allowed after the signals are completed during which the
disc or finger is stationary, permitting the signal to be seen. After the expiration
of the said period it is automatically returned to the zero position. This is effected
in the following manner. The spindle has attached to and wound on it or on to a
barrel fixed on it a chain or cord H to one end of which a weight is attached.
As the spindle revolves it winds up the cord H and the force exerted by the weight
is always tending to turn the spindle back again to zero. Instead of a weight and
cord, I may use a coiled spring or equivalent device to return the finger. A detent
pawl J engages with the teeth of the ratchet wheel being drawn towards it by the
spring G and prevents its return until the detent pawl is released. The armature B
is fixed to a lever K the outer end of which is forked passing under a piu in the
rod N fastened to the lower end of which is a piston P working in the dashpot L.
The latter can be of any ordinary construction and is suitably arranged to retard
the movement of the armature when released. The effect is that at the expiration
of any suitable interval the fall of the piston in the dashpot automatically releases
the detent pawl and allows the force exerted by the weight or spring to return the
disc or finger to the zero position, a suitably placed stop being provided to prevent
too great a return movement.
The dashpot does not in any way prevent the armature lever from being
immediately released and so engaging another tooth to give a further forward
movement to the disc or spindle if desired but is arranged so that on the completion
of the desired number of signals the disc or finger shall remain in position for a
definite fixed period before returning to the zero position. I also arrange that the
detent pawl J may be instantaneously released either after or before all the signals
are transmitted and the disc or finger set back to zero position by the action of a
supplementary polarised relay M worked by suitable means such as pressing a button
or key which may be done manually or by the movement of the machinery or
otherwise as may be arranged. The relay M is wound in series with A and when.
the ordinary current is passed through it attracts the magnetised armature O
pivotted at O. The inner end O2 of the armature is kept in the position shown
in Fig. 1 by the weight of an arm S attached to it which can be pressed against
the spindle of the valve T at the bottom of the dashpot L. When a supplementary
current is passed through M in the opposite direction to the normal the polarity
of M is reversed, the end O2 of the armature O is repelled and the end O³ attracted,
the arm S being thus raised so as to press the spindle of the valve T and open it,
allowing the piston to descend, thus releasing the detent pawl J, and permitting the
weight or spring to return the disc or finger to zero.
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.) The means by which any desired number of signals successively transmitted
as described are visibly indicated in the manner substantially as herein described
and illustrated.
(2.) The combination of an electro-magnet an armature operated thereby and
coupled to a pawl by means of which a ratchet wheel and a disc or finger are
partially rotated a detent pawl controlled by a dashpot and a weight and cord all
arranged in the manner and for the purpose as herein described and illustrated.
(3.) The combination with an apparatus for visibly recording the number of
signals transmitted in the manner described of a secondary electro magnet or.

page_text: polarised relay and armature whereby the detent pawl can be released so as to allow
the indicating finger or disc to be returned to its initial position substantially as
described.
Dated th of Ton 1907
MAUNSELL MERCIER.