US 1743777 A
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Description (OCR text may contain errors)
Jan. 14, 1930. R, HORNBY, ET AL 1,743,777
ELECTRIC PREPAYMENT SUPPLY SYSTEM Filed Dec. 2l, 1926 Patented Jan. I4, 1930 ROBERT OBNBY AND EDWARD HOWARD WRATTEN, F LONDON, ENGLAND nLncraIc rnnramnn'r SUPPLY srsrnm Application filed December 21, 1926, Serial No. 159,224, and in Great Britain September 28, 1926.
rangement will serve as a collecting box or register for the-weekly or other instalments,
and if the hirer fails to keep up the payments by the insertion of the necessary coin Vor instalment periodically, then the circuit is interrupted automatically at the end of the period last paid for, and remains broken until restored bythe insertion of a fresh coin or coins. The actual consumption of energy is'ineasured by a separate meter of any suitable kind, used in combination with the coinslot apparatus. The system works however, independently of the current used, and still operates to break the circuit at the end of the pre-paid period even if no current has actually een used.
In this way the use of the system provides an incentive to the user or hirer to keep up his payments regularly even if he should not be requiring to make use of the circuit, or the appliances hired, during the period covered by the instalment. Moreover the apparatus will serve both as an instalment register and a collecting box, so that it will only be necessary or a collector to call, say once aquar# ter to take out the coins, instea of having to call for them each week for instance.
According to the invention, the time-limit device or interrupter is so arranged that after a pre-determined time, a fresh coin must be inserted to obtain a supply whether any current has been used or not. For this purpose the apparatus comprises in combination, an ordinary energy meter and an automatm switch or interrupter provided with a device for opening it after a pre-determine period, say a wee for instance, although 1n some cases (such as when applied to a gey ser) the period may be only a quarter of an hour for example. The timing device may comprise a constant-speed motor or a clockwork arrangement, and be coupled to the switch by mechanism which, after one run, is re-set for a further run simply by the insertion of another coin and the closing of the switch.
In order that the invention may be clearly G0 understood and readilyl carried into eect, reference will now be had by way of example to the accompanying diagrammatic drawings, in which:
Fig. 1 illustrates one arrangement of a s stem such as referred to, intended chiefly gol: collectingweekly instalments.
Fig. 2 illustrates in principle, the essential part of the coin-slot mechamsm which is employed. I p
The left-hand portion of Fig. 1 re resents the timing device or constant-Spee motor. The right-hand portion shows the coin-slot mechanism which may be of any suitable known construction and contains the automatic interrupter or switch and its controlling cam. The middle portion represents the reducing gear4 which serves to connect the switch-control cam with the timing motor,
and is-so adjusted that the said motor kwill have to run say for a week in order to turn back or reverse the control cam by the same amount which it has been put forward (or wound up) on the insertion of the coin or coins. At the bottom is indicated an ordinary 8x5 consumers'circuit, the supply to which is to be pre-paid for a certain time. p
-The timing mechanism illustratedresembles in general arrangement, a disc motor such as used in electric meters. a is the disc; v9B
b* the actuating or `driving ma ets,.`and c 4the brakemagnet,y these magnets eing laminated in 'the ordinary way. g
d1 d1 are the consumers mams. In these are included an ordinary meter al for measuring the actual energy consumed, such energy being delivered by the supply mains D. e represents .the automatic-control cam,
which is driven slowly -from the timing m0- tor aand allows the switch'f to spring openlpoo K after a pre-determined interval and interi'upt the current to the apparatus to be controlled, such as a domestic motor g or a set of lamps.
In order that the speed of the dise motor a may keep practically constant and that it may be independent of ordinary working fluctuations in the supply voltage or potential, the magnets b c may have their exciting coils b1 o? connected in shunt across the consumers mains d1. Thus if the potential drops and slightly reduces the force of the actuating magnets, this is compensated for by the brake magnet c being correspondingly weakened at the same time, and hence the speed of the disc a is not materially affected.
The magnets b b* have (in the ordinary way) a closed-circuit winding b2 which, like a transformer winding, is energized from the shunt winding b1 and sets up thenecessary phase-reaction.
The coin-slot mechanism illustrated will now be briefly described for the sake of clearness, although its construction is not part of the invention. This mechanism isprovided with a casing F having the usual coin slot f1, the winding handle or key f2, and a wii.1 dow f8 through which the counter or dial is read. Internally (as in Fig. 2) it comprises an epicyclic or differential toothed gear L h1 11.2v for working the switch-control cain e. This cam e is mounted at one end ot a main spindle e1 from which extends a radial. arm e2 carrying the planet pinion h2 of the differential gear. At the other end of the main spindle e1 is the pointer e3 of the dial.
The two opposed discs or crown-wheels hh of the differential gear are carried by sleeves h3 free to turn on the spindle e. The righthand disc h1 is geared as shown by a suitable set of tooth wheels i1, with the coin-receiver or drum c'. When a coin is inserted into the latter through the slot f1, and the key f2 is turned in the usual way, the switch f closes and completes the circuit. At the same time the drum imparts a partial turn'to the disc h1, which causes the planet .pinion and arm e2, to travel forward with it, so turning thespindle e1 and putting the cam e into the position for keeping the switch closed.
During this motion of the pinion h2, theother disc h remains stationary. Said disc h is however geared through a pinion h* and the reducing gear j, etc. (see middle of Fig. 1) to the timing arrangement a. Consequently when the control switch f is closed, the cui'.- rent starts the motor disc a and the latter very slowly turns the disc h in the opposite direction to that in which the disc h1 was turned, so causing the planet pinion h2 and the arm c2 tovtravel back towards its original position.
In this movement the radial arm e turns the spindle e1 and control-cam e back to the pojnt where, after the lapse of the period of time which has been paid for, the said cam e releases the tail orcatch f* of the switch f, thus allowing the latter to be opened by a spring (such as f5) so interrupting the supply of current.A
The reducing gear j which connects the disc a and its spindle a with the coin-slot mechanism does not call for special mention, beyond the fact that where the time period to be prepaid is a long one (such as a week) it is of a very high ratio, so that for instance after the motor disc a has runfor a week, the cam e will only make a half turn. Between this gear and the coin-slot mechanism are interposed removable wheels or changegears jl j which can be changed when the rate of working is to be altered. This may be necessary when the meter is to be adjusted to take coins. of a diferent value, or is intended to allow a di'erent length of supply for the same kind of coin.
For direct-current working, the plain disc a may be replaced by one having a suitable winding of the known kind and a 3-part commutator, the operating current being that of a dry-cell for instance, or one derived at very low voltage by tapping a section of one of the mains on the potentiometer principle. In x such a case the disc may rotate in the field of a permanent magnet, instead of the electro ma ets b b* of Fig. 1. V
en the s stem is used for certain purposes, such as or controlling the supply to an electric geyser (as for instance in hotels -to enable the guests to prepay for the use of a bath) the time interval required to be covered may only be relatively short, for instance a quarter of an hour. In these cases any convenient clock-work arrangement (such as that l of an alarm clock) may be used in lace of the motor or disc a. Also the switc f may be made correspondingly stout or heavy to take the rather large currents which have to be dealt with in a geyser or heater. The clockwork is made so that it may be re-wound by the opening of the switch or turning of thekey f2 and be started by the closing of the switch f.
'In some cases the apparatus may be made to collect arrears of instalments. To this end the timing device may be arranged to still remain in circuit when the switch opens at the end of the pre-paid period. This may be provided for either by connecting the said device directly in `shunt across the leads in advance of the switch, or b roviding special contacts ,on the latter. ith such an arrangement the planet pinion goes on. turning backwardbeyond the position at which the switch normally opens. Consequently for resuming the supply two or more coins (representing the arrears) have to be inserted before the pinion regains that position, the handle or key being of course turned after the insertion of each coin.
' Obviously the above arrangements may be modified in various ways according to circumstances in carrying out the invention,
without departing from the general nature thereof.
We claim: y
1. In an electric supply system, a consumers circuit, an energy-meter for measuring the consumption in said circuit,|a coincontrolled switch which both opens and closes said circuit, a constant-speed motor having' its windings constantly in shunt across the mains, and means actuated by said motor for causing said switch to open the consumers circuit after a predetermined time whether any current has been consumed or not, sub1 stantially as described.
2. In an electrlc supply system, a consumers circuit provided with a meter, a coincontrolled switch for closingsaid circuit fora predetermined time corresponding to the value of the coin but independent of the amount of current used, and a constant-speed tures.
electric motor to open said switch after such predetermined time, said motor having its actuating and braking magnets in shunt across the consumers mains, whereby the time that the switch remains closed isindependent of iuctuationsin the supply voltage as well as o current consumption, -substantially as described. l' v In testimony whereof we affix our signa- ROBERT HORNBY. EDWARD HOWARD WRATTEN.