Improvements in Coin-controlled Mechanisms for use in connection with Prepayment Electric Meters or the like.
Year: 1899

page_text: Date of Application, 8th Dec., 1899-Accepted, 15th Sept., 1900
Improvements in Coin-controlled Mechanisms for use in connection
with Prepayment Electric Meters or the like.
We, THE BRITISH THOMSON-HOUSTON COMPANY, LIMITED, of 83, Cannon Street,
in the City of London, Electrical Engineers, do hereby declare the nature of our
said invention (which has been communicated to us from abroad by Frank P.
Cox, residing at Lynn, in the County of Essex, State of Massachusetts, United
States of America, Electrical Engineer,) and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
The present invention relates to coin-controlled mechanisms and has for its
object to improve their construction. The invention is directed more particularly
towards the means employed for ensuring the opening and closing of the circuit
of prepayment meters or other electric devices such as fan motors.
In the accompanying drawings, which show an embodiment of our invention,
Fig. 1 is a front elevation of a meter with the casing shown in dotted lines;
Fig. 2 is a side elevation of the meter, the casing being shown in dotted lines
as before; Fig. 3 is a detail view showing the switch for making and breaking
the circuit; and Fig. 4 is a diagram of connections.
The invention is shown in connection with one of the well-known Thomson
recording wattmeters, in which A represents a supporting frame for the various
A¹ is the main shaft and mounted thereon is an armature A²
parts of the meter.
and a damping disc A³. The armature is mounted for revolution between the
stationary field coils A+, which are included in the main circuit, and the damping
the poles of the damping
disc is mounted for rotary movement between
magnets A5. On the upper end of the armature shaft is a worm A6, and meshing
with this worm is a worm-wheel A7 which is connected by suitable gearing with
the registering mechanism and the indicating hand or pointer A8. Mounted on.
the front of the meter frame A is a coin-controlled device for regulating the
action of the meter. This device consists of a main coin chute B and a secondary
coin chute B¹, the latter being provided with a slot in the front to show the
number of coins contained therein; and between the two portions of the coin
chute is a rotary coin receiver B2. The coin receiver is provided with a receptacle
for receiving the coin after it is inserted in the chute B, and a coiled spring b
for returning it to the normal position as soon as the coin has been deposited in
the secondary coin chute B¹. The object of this device is to prevent the insertion
of improper articles into the coin chute for the purpose of actuating the meter.
The secondary coin chute 13 extends transversely across the front of the meter,
and the right-hand end is slightly lower than the left-hand end and is curved
downward so that the coins always have a tendency to move towards the right
and drop into engagement with the rotary coin wheel C and the flexible spring D.
The coin wheel C is not included in the circuit, as will be seen by reference to
Fig. 4. The flexible spring D situated at the right of the coin wheel is con-
nected to one side of the circuit, and at its lower end is provided with a silver
contact which is arranged to establish connection with the fixed contact E, when

page_text: a coin passes from the coin slot B¹ and rests between one of the arms of the coin
wheel and the contact 1). The circuit connection of this particular feature of
the meter will be described hereinafter.
The coin wheel C is mounted on a shaft which is provided with suitable
bearings, and meshing with the arms of this wheel is a four-arm cam-wheel F.
The arms of the wheel F are enlarged at their outer ends to form cams, and these
cams engage with the arms of the wheel C and regulate its motion.
The cam
wheel is mounted on a shaft, and carried by the shaft is an arm or
pointer As which is designed to indicate the movements of the meter mechanism.
Situated below the coin wheel C, and to the left of the coin slot, is a pair of
contacts G and G¹. The former consists of a long thin piece of spring metal and is
connected to one side of the circuit, while the latter consists of a fixed piece of
metal and is connected by a suitable wire to the opposite side of the circuit. The
arrangement of the contacts and coin chute above referred to, is such that the
coin first closes the circuit between the contacts D and E, and later the same
coin closes the circuit between contacts G and G¹. When only a single coin is
deposited in the meter, the closing of the circuit between contacts D and E
energizes the magnet H, which closes the main circuit of the meter. After the
consumer has received the prepaid amount of energy, the rotation of the coin
wheel C permits the coin to drop and open the circuit between contacts D and E,
the main circuit however still remaining closed. The next instant the coin
drops on the flexible contact G and by its weight closes the circuit through the
releasing magnet O¹. As soon as this is done magnet O' is momentarily energized
and the tripping mechanism is released in a manner more fully described herein-
after. In other words, the armature of the meter constitutes an automatic
register controlling device, and drives the coin wheel to a point where it releases
the coin, and the latter again becomes operative by closing the circuit of the
releasing magnet. When two or more coins or other tokens are on deposit in
the apparatus at the same time, the first coin is released by the coin wheel C
when the prepaid amount of energy has been consumed, but before it can drop
to a point where it will close the circuit between the contacts G and G¹ the second
coin has advanced to a point where it closes the circuit of the magnets H; this
prevents the interruption of the main circuit.
The coin-actuating mechanism of the meter and also the gearing are supported
by the back plate 133, and this plate is supported by a number of lugs A³ pro-
jecting outward from the meter-frame A.
The plate being secured in place by screws, it is a very simple matter to
remove the entire mechanism, either for inspection or repairs. A second
plate B, parallel with the first, and secured thereto by screws, affords a support
for the coin chute and other parts of the prepayment mechanism. The main
and secondary coin chutes are formed in the casting I, which is secured to the
front of the plate B by screws; this arrangement permits the ready assembling
or taking down of the various parts. The gearing for operating the pointer F
may be of any suitable construction, and is located between the plates B³ and B*.
Mounted on the insulating support is an L-shaped bar J of magnetic material;
this bar forms the yoke between the cores of the magnets H. The cores of the
magnets are provided with conical tips which extend through the movable
armature H this arrangement permits a wide range of movement of the
armature, with a substantially constant pull. The support K is made of fibre or
other insulating material, and is retained in place by screws K', which enter
lugs projecting from the meter-frame. Mounted on the support K is the arma-
ture H¹ of the magnets H. The means employed for supporting the armature
consist of a thin strip of spring metal L, such as phosphor bronze for example,
which strip is bent downward at right angles to the plane of the armature and
is secured to the support by screws. A part of the piece L is bent downward
as shown at to provide an additional spring to raise the armature to the position
shown, and by moving the screw in or out, the tension of the spring can be

page_text: adjusted. On the outer end of the strip L is a spring contact L'; in the present
instance this contact is made of silver since it makes better contact and is not
so liable to corrode as other metals. Situated directly below the contact is a
second contact M, also covered with silver, which is carried by a small plate
mounted on the top of the left-hand magnet H. Mounted on the bar J is an
L-shaped piece of non-magnetic material N, and secured thereto is a small
magnetic blow-out N¹ for disrupting any are which may be formed when the
circuits between the contacts Li and M is interrupted. This magnet is of the
horse shoe type, and is energized by a winding that is included in the main
circuit of the meter.
Mounted on the top of the insulated plate K is a bracket O, and secured to the
bracket is an ironclad shunt-wound magnet O'; this magnet is provided with
an armature 02 having a horizontal movement, which armature is arranged to
release the armature H¹ and permit the contacts L¹ and M to separate. Secured
to the front of the armature is a bifurcated arm 0³, best shown in Figs. 2 and 3.
Pivotally mounted on the head of left-hand magnet H is a latch P; this latch
is composed of two hooks connected by a rod P. The rod P₁ also serves to
connect the outer ends of the bifurcated arm 03. Mounted on the top of the
armature H and supported by posts h, is a plate h¹, the latches P and plate ¹²
being so arranged that they will engage when the magnets H are energized and
the armature H¹ moved downward to a point where it closes the circuit between
the contacts L' and M. Between a stud Q mounted on the upper head of the
right-hand magnet H and the armature 02 of the releasing magnet is a spring Q
This spring is designed to pull the armature (2 to the left and force the latches P
over the plate h¹ in order to hold the contacts of the main circuit in their closed
position.
Situated in the lower right-hand corner of the meter and directly under the
secondary coin chute B is a tubular coin receiver R. This receiver is held
in position by a pivoted plate R₁ located beneath the meter, and retained in
place by a wing nut R2, which nut can be sealed in place in the ordinary manner
to prevent tampering with the meter.
Referring to Fig. 4, the circuit connections of the meter will be described.
1 and 2 represent supply mains, and 3 and 4 the house mains supplying current
to the lamps or other translating devices 5. Current enters through the main 1
and passes through the winding on the blow-out magnet to contact M, thence
to contact L and the spring plate L, located on top of the armature H¹, through
the field coils A to the house main 3. The circuit from main 2 is to the
strip S, located in the back of the meter, to the house main 4. The armature A²
of the meter is connected between point and the strip S; in other words, it is
connected in shunt to the house mains. In circuit with the armature is a starting
oil 7 furnishing an initial field, and a resistance 8 for reducing the amount of
current owing in the circuit; which is mounted in an envelope 81 and placed
n the back of the meter. The magnet H is employed to close the main circuit
of the meter and also that of the consumer, and its winding is connected to wire 9
on one side and to contact E on the other. Contact D), which forms a part of the
ast mentioned circuit, is connected, when a coin is placed in the meter, to the
trip S through a resistance 10 and wire 11. The resistance 10 is wound on a
pool and is secured to one of the vertical side frames of the meter. The
magnet 01, for releasing the armature H¹ serves to interrupt the circuit of the
neter, and is connected between point 12 on wire 9 and the fixed contact G¹.
The circuit is completed through the flexible contact G, resistance 10, wire 11 and
trip S. By this arrangement we are enable to use a single resistance for.
educing the current in both the magnets H and. I. We have found that in
eters of this class it is preferable to have one magnet for positively ensuring
he closing of the circuit, and a second magnet for positively ensuring the opening
f the circuit. With the parts arranged as shown in the diagram, the main
ircuit is closed and the coin 13 is held between the coin wheel C and the

page_text: flexible contact D.
arma-
The coin is released by reason of the rotation of the cam
wheel F and the arm wheel or coin receiver C, due to the operation of the meter.
When the coin drops the spring of contact D is sufficient to cause the interruption
of the circuit at that point, and consequently the magnet H becomes de-energized.
The spring plate L is not however, permitted to raise the
ture Hand open the main circuit until the magnet 0¹ is energized.
When the coin drops from the position shown, and prior to falling into the coin
receptacle R, it strikes the contact G and momentarily closes the circuit through
the releasing magnet 01. As soon as this magnet is energized, it attracts the
armature against the action of the spring Q and causes the latch P to release
the plate h¹, and the armature H' moves upward due to the spring plate L. This
causes the contacts L¹ and M to separate and interrupt the circuit of both the
meter and the consumer, the magnet N¹ quickly disrupts any are which may be
formed at that point.
It will be seen that the coins do not form a part of an electric circuit; this
we have found to be a desirable feature, since it prevents all burning of the
coins which might be occasioned if the coin acted as a part of the circuit. It
will also be seen that by the arrangement shown the currents handled by the
contacts will be so small as to decrease the danger of arcing, and consequently
the burning, to a minimum.
By the arrangement described and illustrated, we are enabled to provide a main
switch of sufficient size to handle the current flowing through the meter in the
consumption circuit without introducing any friction into the operation of the
meter; and the weight of the coin is utilized to overcome any friction of the coin
and cam wheels. We are also able to get any desired amount of energy for opening
or closing a switch or switches, since the magnets can be wound to produce any
desired result.
In practising our invention, it is unnecessary to follow the arrangement shown
in the drawings, since the invention can be applied to any sort of device which
is wholly or partially electric, where it is desired to positively open and close
an electric circuit. The invention may be advantageously applied where the
coin forms a part of the principal or a secondary circuit, or where the coin is out
of circuit and its weight is utilized to close the main circuit.
Having now particularly described and ascertained the nature of our said
invention (as communicated to us from abroad) and in what manner the same is
to be performed, we declare that what we claim is:-
1 In a coin-controlled mechanism, the combination of an electric circuit, a
circuit-breaker included in the circuit, magnetically controlled means for con-
trolling both the opening and closing of the circuit-breaker, a coin-controlled
device for causing the closing of the circuit-breaker, and a separate device for
causing the opening of the circuit-breaker.
2-In a coin-controlled mechanism, the combination of an electric circuit, a
switch included in the circuit, a magnet for causing the closing of the switch:
a second magnet for causing the opening of the switch, and a coin-controlled
means which is so arranged that the coin causes the closing of first one circuit
and then another.
3-In a coin-controlled mechanism, the combination of an electric circuit, a
switch included in the circuit, a magnet for causing the closing of the switch, a
second magnet for causing the opening of the switch, and a coin-controlled
means which is so arranged that it first causes the closing of the circuit, and
then the opening of the circuit, a single coin causing both operations.
4 In a mechanism controlled by a coin or other token, the combination of a
circuit, a switch in the circuit, a magnet for closing the switch, a magnet for
opening the switch, contacts arranged in the path of the coin or token in such
manner that first one magnet circuit is closed and then another; and means for
preventing the closing of the second circuit until after a certain interval.

page_text: 5-In a token or coin-controlled electrical apparatus, the combination of a
circuit, a switch therein, a magnet for closing the switch, a second magnet for
opening the switch, a winding for each of the magnets, through which less
current is permitted to flow than in the first mentioned circuit, contacts for
5 closing the circuit of the magnets in such a manner that the switch is first
closed and then opened, and means for retarding the passing of the coin so that
there will be an appreciable time interval between the closing and opening of the
switch.
6 In a prepayment mechanism for electric meters, the combination with a
meter and the main circuit for its coil or coils, of a normally open-circuit-closer
included in the meter circuit, magnetically controlled means for respectively
opening and closing said circuit-closer, a coin-controlled device for setting into
action the means for closing the circuit-closer, and a separate device for setting
into action the means for opening said circuit-closer, substantially as set forth.
7 In a prepayment mechanism for electric meters, the combination with the
register mechanism of the meter and the main circuit for the meter coil, of a
normally open circuit-closer included in the meter circuit, separate electro-
magnetic means for respectively controlling the opening and closing of said
circuit-closer, a coin-controlled device for setting into action the means for
closing the circuit-closer, and an automatic register-controlled device for setting
into action the means for releasing or opening said circuit-closer, substantially as
specified.
8 In a prepayment mechanism for electric meters, the combination with the
register mechanism of the meter, and the main circuit for the meter coil, of a
circuit-closer included in the meter circuit and having a movable member,
separate electro-magnetic means for controlling the moving of said movable
member of the circuit-closer to operative and inoperative positions, a coin-con-
trolled device for setting into action the means for adjusting said movable member
to an operative position and an automatic register-controlled device for setting
into action the means for releasing or moving said movable member to an
inoperative position, substantially as set forth.
9 In a prepayment mechanism for electric meters, the combination with the
register mechanism of the meter and the main circuit for the meter coil, of a
circuit-closer included in the meter circuit and having a movable member, a main-
circuit-closing armature carrying the movable member of the circuit-closer, an
electro-magnet for moving said armature in one direction electrically-controlled
means for regulating the moving of said armature in an opposite direction, a
primary-circuit-closer included in a circuit with said electro-magnet and the
main line connections for the meter, a coin-controlled device for operating the
primary-circuit-closer, and a register-controlled device for automatically setting
into action the means for moving said armature away from its magnet, sub-
stantially as specified.
10 In a prepayment mechanism for electric meters, the combination with the
register mechanism of the meter, and the main circuit for the meter coil, of
circuit-closer included in said meter circuit, and having a movable member, a
main-circuit-closing armature carrying the movable member of said circuit-
loser, an electro-magnet for moving said armature in one direction, a separate
lectro-magnet for regulating the moving of the armature in the opposite direc-
ion, separate local circuits for each of said magnets, a coin-controlled device for
losing one of said local circuits, and a separate device for closing the other of said
ocal circuits.
11 In a prepayment mechanism for electric meters, the combination with the
egister mechanism of the meter, and the main circuit for the meter coil of a
ircuit-closer included in the meter circuit and having a movable member, a
hain-circuit-closing armature carrying the movable member of the circuit-
loser, an electro-magnet for moving said armature in one direction, a separate
ectro-magnet for permitting the armature to move in the opposite direction,

page_text: separate local circuits for each of said magnets, a coin-controlled device for one
of the local circuits and a register-controlled device for automatically closing the
other of said local circuits.
12 In a prepayment mechanism for electric meters, the combination with the
main circuit of a circuit-closer included in said circuit and having a movable
member, a main-circuit-closing armature carrying the movable member of said
circuit-closer, an electro-magnet for moving said armature in one direction, a
separate electro-magnet for permitting said armature to move in the opposite
direction, coin-controlled means for causing one of said magnets to be energized,
and separate means for causing the other of said magnets to be separately and
independently energized.
13 In a prepayment mechanism for electric meters, the combination with
the main circuit of a circuit-closer included in said circuit and having a movable
member, a main-circuit-closing armature carrying the movable member of the
said circuit-closer, an electro-magnet for moving said armature in one direction,
a locking device pivotally supported at one end and having locking engagement
at its other end with said main armature, an electro-magnet arranged adjacent to
the locking device for controlling the movement thereof in one direction, a
spring, separate local circuits for each of said magnets, a coin-controlled device
for closing one of said local circuits, and a separate device for closing the other
of said local circuits.
14 In a prepayment mechanism for electric meters, the combination with
the register mechanism of the meter and the main circuit for the meter coil,
of a circuit-closer included in the meter coil circuit and having a movable
member, a main-circuit-closing armature carrying said movable-member of the
circuit-closer, a setting magnet for moving the main armature in one direction, a
locking device pivotally supported at one end and having a loose locking engage-
ment at its other end with said main armature, a release magnet for controlling
the movement of the locking device in one direction, a spring for moving the
circuit-closing armature, separate circuit-closers respectively for the setting and
release magnets, a primary-circuit-closer included in the circuit with the setting
magnet and the circuit-closer therefor, a circuit-closer controlled by the register
mechanism and included in a circuit with the release magnet, and a coin-con-
trolled device for operating said primary circuit-closer.
15 In a metering device, the combination of a coil or coils included in a
circuit, a switch which is normally open included in the meter circuit.
magnetically-controlled means for regulating the opening of the switch,, and
magnetically-controlled means for regulating the closing of the switch.
16 In a metering device, the combination of a coil or coils included in a
circuit, a switch which is normally open included in the meter circuit,
magnetically-controlled means for regulating the opening of the switch, mag-
netically-controlled means for regulating the closing of the switch, and coin-
controlled means for rendering the magnetic means operative.
17—In a prepayment mechanism the combination of a main circuit, a circuit-
breaker having a movable member, an armature carrying the said member, and
two magnets which act to control the armature.
18 In a coin or other token-controlled apparatus, the combination of two
normally open circuits, contacts for closing the circuits, and means for directing
the passage of the coin or other token in such manner that it causes the closing
of both circuits.
19 In a coin or other token-controlled apparatus, the combination of two
normally open circuits, contacts for closing the circuits, and a chute for directing
the movement of the coin or token in such manner that the coin or token first
closes one circuit and then the other.
20-In a coin or other token-controlled apparatus, the combination of two
normally open circuits, a magnet included in each of the normally open circuits
and arranged to perform useful work, a chute for directing the movements of the

page_text: coin or token, and contacts located near the chute for closing the circuit of the
magnets; the arrangement being such that the circuit of one magnet is closed
by a coin or token, and then the circuit of the second magnet is closed, the same
coin or token acting in both cases.
21-In a coin or other token-controlled apparatus which is capable of receiving
more than a single coin or token, the combination of a magnet for closing a main
circuit, a magnet for opening the circuit, means located in the path of the coin or
token for closing both of the magnet circuits, and means for permitting the
second coin or token to advance to a point where it completes the closing of the
circuit of the first magnet prior to the time that the first coin completes the
circuit of the second magnet, so that there is no interruption of the main circuit.
Dated this 28th day of November 1899
THE BRITISH THOMSON-HOUSTON CO. LTD.,
ALFRED CLEMENTS,
Assistant Secretary,
W. MARTINDALE,
T. A. THOMPSON,
} Directors.