US2623621A - Coin-controlled credit system - Google Patents

Description

Dec. 30, 1952 R. L. ARMOR Erm.

COIN-CONTROLLED CREDIT SYSTEM Filed March l0, 1947 ATTORNEYS I Hi Patented Dec. 30, 1952 COIN-CONTROLLD CREDIT SYSTEM Robert L. Armor, Los Angeles, and Harry I. Winslow, North Hollywood, Calif., assignors of onehalf to E. T. Mape, San Francisco, Calif.

Application March 10, 1947, Serial No. 733,701

6 Claims.

The present invention relates to a coin controlled credit system, and more particularly to an electronic credit system for use in coin controlled mechanisms whereby diiierent selected numbers of operations of a coin controlled mechanism may be had, the number being determined by the denomination of a coin deposited therein.

In the past a number of developments have been made whereby successive operations of a coin controlled instrument could be regulated by depositing coins of different denominations therein. Such credit systems usually have been mechanical, and subject therefore to the substantial cost and necessity for close adjustment and frequent repairs which such mechanisms usually entail. Where attempts have been made to produce electrical credit systems, they usually have involved circuits that are so complicated as t invite undue service and performance difficulties.

An object of the present invention is to make an improved and simplified coin controlled multiple stage credit system.

Another object is to make a coin controlled credit system whereby a plurality of operations of a controlled device may be regulated by the denominations of coins deposited in the credit system.

Another object is to make a relay chain credit system in which operation of various stages of the system, and therefore the amount of credit established, is controlled by the denominations of coins deposited therein.

Another object is to make a coin controlled credit system which is operated electrically, and which is arranged so that the functional control of the system is removed from the hands of an operator.

Another object is to make a coin controlled credit system in which successive operational impulses result in exhausting successively a credit storage arrangement of the system.

Another object is to operate successive stages of a multiple stage credit system by short time electrical impulses.

These and other objects and advantages of the invention will be brought out more fully in the following description and in the accompanying drawings, comprising one sheet. In the drawings:

Fig. 1 illustrates a schematic layout for a coin controlled credit system embodying the present invention, a signal operating circuit being shown in heavier lines; and

Fig. 2 shows a portion of the circuit or Fig. l with a pair of operating switches, which are illustrated in their normal position in Fig. 1, as they would appear when one of them is moved to an operated position.

The present illustrative circuit is shown as connected to a selection system of a usual type such as may be employed on coin controlled music boxes. Only a portion of the selection system is shown however, and it will be clear to those familiar with the art that the present credit system is adapted equally well to other coin controlled functions, such, for example, as coin changing systems and the operation of other coin controlled mechanisms. Such functions may include the selective operation of a plurality of circuit instrumentalities, or the repetition of the operation of a single instrumentality.

In the circuit illustrated, the coin selecting and testing mechanism is not illustrated, since any suitable mechanism of this character may be employed. Three coin operated switches are illustrated, however, and these switches are designated by numerals Ill, II and I2. The switch Il? is intended to be closed by the insertion of a quarter; switch II by a dime; and switch I2 by a nickel.

A plurality of selectively operated push button switches I3 and I4 have individual push button extensions II, as illustrated. Each switch has a pair of switch points I5 and I6 which are adapted to close with contact members I8 and I9, respectively, on an operation of the switch. The push button portion II of each selector switch is connected by an insulative mechanical connection to a sliding contact member 20, which normally connects line contacts 2I and 22.

When a push button l1 is pushed in to operate the switch, it connects the switch points I5 and I6 to the contact members I8 and IS. At the same time it disconnects the slide 20 from the contact member 22 and connects the contact 2| with a contact 23, as illustrated in Fig. 2. The contact 23 is connected to a conductor of the selector signal circuit to be described later herein.

A condenser 24 is connected into the signal circuit so that when al1 the selector switches are in normal condition the condenser will receive a charge, while, when any of the selector switches is operated, the charge of the condenser will be employed to operate, momentarily, a master relay 25, When the system has a credit established therein, such operation of the master relay will operate the selector signal circuit and exhaust one stage of its credit.

A plurality of operating relays 21, 28, 29, 30, 3l and 32 also are provided to control the operation of the system. The various conductors which are employed in the system will be given designating numerals in connection with a description of their respective functions.

One side of the coil of the master relay 25 is connected through conductors 40 and 4I to a line conductor 42 which in turn is connected to the negative terminal of a suitable source of direct current electricity. This same negative line conductor l2 also, it will be noted, is 00nnected toV one sidet ofk the condenser 245.

When all of the selector signal switches, such as I3 and it, are in their normal positions, as illustrated in Fig. 1, the condenser 24 will receive a charge by a circuit which-runs vfrom-the` negative line conductor l2 to the condenser, and thence from the other side of `the condenser through intermediate conductors i3 and lill, the normally closed switch slides 29,'and conductors 41 and d8, to a positive line conductor n59: Ther positive line conductor 49 may be connected to the positive terminal ofthe current source vto which the other line conductor 42 is connected.

When any of the selector switches, such asV I3 or I4,jis moved to anoperated position, as shown inY Fig. "2', 'the movement of the slide 29V breaks the charging circuit to the condenser, and closes the switch points I5' and l, with the contacts Illv and-19. side-of the condenser 2llthrough the conductor 43,5 thence throughthe contacts I5, I6, i8 and I9? to a conductor Siliwhichis connected Vto one side of the operating coil of the relay 25. l'rom the other side of the coil of relay the con'- ductors 49, il and 42 complete the circuit to the other side of the condenser 2d. The charge which is accumulated in the condenser 2t, while it is on the'line, thus is permitted to flow through the coil of the relay 25, causing a momentary' energization of relay 25 which is suiiicient 'to operate it.

It is apparent from the above Vdescription that it makes no difference how one operates'the buttons I3 and lll; whether he operates them violently, or slowly, or trickily in any manner. The most and least that can occur is the momentary pulsation of the master relay 25 caused bygthe discharge of the-condenser 24, When the switch button Il is released, the switch restores to normal, the condenser is placed back on the line, aspreviously explained, and the condenser again becomes recharged,

With no coins insertedv inthe device to close any ofthe switches I0, Il and I2, and none of the other relays operated, operation of the selector buttons I3 and It merely causes a momentary pulsation of the master relay 25, and does not produce an energization of the selector signal circuit controlled by the present credit system.

In order to establish a creditV in this system, itis necessary to operate one or more of the relays 21-32 inclusive. The operation of these relays isY accomplished as follows: It will be noted that one'terminal of the coil of each of these six relays is connected to the positive line conductor 49. The other terminal of the coil of each of these` relays is connected tothe normally open inner'pair of points of the relay, This is illustrated, for'example, in relay 2? where the coil of the relay is connected to the inner, normally open, pair of contacts 5l. From the other of these points a conductor 52 is connected through a resistance element 53 and the conductor 4I tothe negative line conductor ft2. This inner pairof points 5I comprises a holding circuit. Similar resistors 59, 55, 59,51 and 5t are connected tosimilar conductors-69, Bi, B2, 631 and B4 for the other relays 28, 29', 39,' 3| and 32, respectively.

Since it requires less-current to hold a relay inA an operated condition than it does to operate it,-the resistor-'associated Witheach vofthe relays is of a resistance toallowtheholding circuitto This completes a circuitfrom one hold the relay operated after it initially has been closed 'by another or operating` circuit tor be described later herein. Preferably the current permitted to flow through the resistor is about half Vof .the normal full line current.

'Ifo proceedwith a description of the operation ofthe credit system, let us assume that the switch I9 has heeniclcsedfb-ythe insertion of a proper 25 coin. The. relay 21 thereupon will be closed by aflow of current from the positive conductor 49 through theV coil of the relay 2'! through a conductor 61, the closed points of switch I9 and thenceithrough a conductor 63 to the negative line conductor 42.

This operates the-.relay 2l and the-,relay will be held closed by the holdingcircuit throughthe inner pair 5I of. contacts of the relay 2l, and through the/resistor t3,r as previously described.

Thisholding Vof therelay 2 is necessary sincethe closing of the switch I0 is only a momentary closingand switch I9 restores to normal assoon asthe actuatingl coin passes it.

Closing'of the relay 2 brings an outer movable contact member 69 thereof into contact With a contact point lll. With the relay 21 thus operated,.on operating any one of the selectorfcontrol switches, such as the switches I3 or I4, an operating circuit through the-coil of the relay 28 will be completed on the-closing of the master relay 25. It Will be noted that the relay 25'has points which close in bothv directions of operation ofthe relay. Therefore, both the energizing and releasing, orclosing and opening operations of master relay 25 must be considered-in the operation of the present credit system.

Thus, with-relay-2l actuated, on an energizing of the master relay 25, an operatingcircuit iscompleted-throughfthe coil ofrelay 28, as followss-From the positive, line'conductor i9 through thecoil of relay-28, through a conductor 1I, and a'conductor i2, tov the closed relay point l0, thence from the movable contact member 69 through a conductor i3 to aninner contact'member lof the relay 25. Since this inner contact s closes on operation of the relay 25, the circuit The openingV of the relay 2 on the returnto normal of relay 25 is accomplished by shorting out the coil of relay 2l, as follows: From the upper side of the coil of the relay 2l the shorting circuit is through the-conductors 49 and 48, normally closed outer contact points 'i3 of the master relay 25, thence through a conductor 19 and a conductor il tothe next to the outer movable contact member tl of relay 2S. Since,aspreviously described, relay 28 now is closed, the

shorting circuit is completed, through a ContactV point 82 and a conductor 83 to the other side of the coil of the relay 2 l.

Fromthe above description it will be apparent that the purpose of the resistor in each of the relay holding circuits is to prevent a flow of current through. the'holdingfcircuit from constitutinga directshort across` the supply'voltage.-

The credit circuit now has been established as above set forth and the operation of the first push button has produced a pulse, or make and break actuation, of the master relay 25. This actuation cf the master relay has transferred the holding of relay 21 to relay 28 which on the completion of the above actuation is the only relay in the circuit which is held closed.

On the actuation of a second selector switch button |1, with the relay 28 held in actuated condition, a circuit will be completed from the condenser 24 through the actuating coil of relay 25, as above described, and the charge on the condenser 24 will cause a pulsation or make and break action of the master relay 25. On this actuation of the relay 25, the relay 29 will be energized by a current flowing from the negative line conductor 42 through the conductor 4|, the closed inner points 14 of the master relay 25, thence through the conductor 13, the normally closed outer contacts 69 and 11 of relay 21, thence through a conductor 34, a closed intermediate contact member 85 and contact point 81 of relay 28, since this relay is closed at this time, thence through conductors 89 and 89 and the coil of relay 29 to the positive line conductor 49. On the restoring of master relay 25 to normal on the completion of its pulse, the relay 28 will be restored to normal by shorting out its coil. This shorting circuit is from one side of the coil of relay 28 through the line conductor 49 and the conductor` 48 to the normally closed outer contact points 18 of the master relay 25. Since these contact points close when the master relay returns to normal on the completion of its pulse, this shorting circuit will continue through the conductors 19 and 39 and a conductor 90 to an outer movable contact member 9| of now actuated relay 29. Thence through a contact point 92, through a conductor 93 and the conductor 1| to the other side of the relay 28. This shorts out the relay 28 which was being held by the holding circuit through the resistor 54.

It will be noted that the relay 39 is not operated on this last mentioned pulse of the relay 25, since on the actuation of the master relay 25, the relay 28 was still closed. Therefore, the intermediate movable contact member 85 of the relay 28 was still in its operated position and out of contact with its outer contact point 94, which it Would be necessary to have closed in order to complete the operating circuit for the relay 30.

On again operating one of the selector switch buttons |1, the master relay 25 again will be operated by a pulse from the condenser 24, as previously described. On actuation of the master relay 25, the relay 39 will be energized by a circuit from the negative line conductor 42, the conductor 4|, the closed inner points 14 of the master relay 25, the conductor 13 to the normally closed outer contact points 69 land 11 of the relay 21. Since this relay now is unoperated, and its outer points are closed, the circuit will continue through the conductor 94 to the intermediate movable contact member 85 of the relay 28. Since this relay also noW has been restored to normal, the circuit will continue through the contact point 94 and a conductor 95 to an intermediate movable contact member 91 of the relay 29. The relay 29, as above described, now is closed, so the circuit will continue through the inner contact point 98 for this contact member and thence through a conductor 99, a conductor and the -coil of relay 30 to the positive line conductor 49.

On the restoring of the master Irelay 25 to normal after the condenser 24 has been discharged, the coil of relay 29 will 'be shorted out by a circuit from one side of the coil 29 through the line conductor 49 and the conductor 49, the normally closed outer points 18 of the master relay 25, thence through the conductors 19 and 80 and a conductor |0| to an intermediate movable contact Imember |02 of the relay 30. Since the relay 30 now is closed, the circuit will continue through an inward contact point |03 of relay 30 and thence through a conductor |04 and the conductor 89 to the other side of the coil of relay 29. This exhausts three of the ve stages of credit established in the circuit by inserting the 25ui coin to close the switch 0.

On the next subsequent actuation of a selector button |1, the relay 3| Will be closed and relay 59 will be opened in the same general manner as that described for the advancing of the relays from 21 -to 30. Since such manner of operation will now be clear to one familiar with the art, it is believed to be unnecessary to trace the circuit in detail. Therefore, after four selections have been made the relay 3| Will be the only one in the circuit which Will be closed.

On the operation oi a selector switch button |1 for the fifth selection, the master relay 25 'again will be closed momentarily and then released by a pulse from the condenser 24. On closing of the conta-cts of the relay 25, the relay 3| 'being closed, the relay 32 will be energized by a circuit, as follows: From the positive line conductor 49 through the coil of relay 32, thence through conductors |05 and |01, a closed intermediate contact point |08 and contact member |99 of relay 3|, thence through a conductor ||0, the normally closed contacts of relay 30, a conductor ||2, the normally closed contact point H3 and the contact member 91 of relay 29, the conduct-or 95, the normally closed contacts 94 and 35 of relay. 28, the conductor 84, the normally closed outer contacts 11 and 69 of the lrelay 21, and thence through the conductor 13 to the inner contacts 14 of the master relay 25. From here the circuit is completed through the conductors 15 and 4| to the negative line conductor 42. On the closing of relay 32, a holding circuit is completed in the usual manner through the conductor |54 and the resistance element 59.

On the return of the master relay 25 to normal at the completion of its pulse cycle, the coils of relays 3| and 32 both will be shorted out by circuits as follows: From the normally closed outer contacts 18 of the master relay 25, through the conductors 19 and 90 and conductors 4 and |5, respectively, to the two intermediate movable contact members ||1 and ||8 of relay 32. Since relay 32 now is closed, the shorting circuit for relay 32 continues from the movable contact member 8, its associated inner contact point |19 and the conductors |01 and |05 to the coil of relay 32, while from the movable conta-ct member |1 the shorting circuit for the relay 3| continues through an inner contact point |20 .and is completed through conductors 2| and |22 to the coil of relay 3|. From the other sides of the relays 3| and 32 the shorting circuit is completed back to the outer contact points 18 of master relay through the conductors 49 and 48. On the completion of the fth step of actuation of the relay circuit, namely, the restoration of the relays 3| and 32, the entire circuit is restored to normal.

Instead of the ve stage credit established by the .closing-of the; switch Vit on the` insertion of a'25 coin, a two-'step credit can'be established by the closing of the switch l by the insertion or a ,10c coin. A single step credit also can be established by the insertion oi a c coin to close the switch l2. On the closing of switch El a circuit will be completed to energize the relay 3S, While on the closing of switch i2 a circuit will be cornpleted to energize the relay 3|. Since the subsequent operations for exhausting the one and two stage credits thus established have already been described, it is believed the operation of these switches will be clear without further description.

Theheavier lines on the circuit drawings designate the signal operating circuit for transmitting a credit signal to the selective mechanism. It will be noted that there are but three pairs of signal operating contacts in the six relays tlf-32 inclusive, namely the points Hill, 25 and |12?. lt will also be noted `that there is but a single pair o conta-ct points in the master relay which control the signal circuit. The contact points |25, |25 and il in the relays 2t, do and 32 respectively are connected in parallel to signal conductors |29 and l. These parallel pairs or" contact points also Iare connected in series with the signal circuit contact |28 on the master relay 25. A conductor itl may be considered as common to one side of the selector or signal circuit, while individual signal circuit selector conductors |32 and |33 are connected one to each of a plurality of select-or signal circuits. By this arrangement, when la credit is established in the circuit so that any of the three pairs of signal circuit relay contacts |25, |26 or |2l is closed upon the operation of the master 'switch 25 to close the signal contact I 28 thereon, -a signal will be transmitted from the common conductor i3! through any of the para-lylel lcontacts |25, |25 and |21 which is closed at the time, thence through the conductor |363 and a conductor I Sli, the closed contact |28 of the master relay, the conductor Alt, the conductor lil", and thence through the slide 2li of any push but-- ton switch which is actuated. From here the signal circuit is completed as through a conductor |32 cr 33 to the signal Control apparatus. The signal control apparatus is of the usual type and is-not illustrated in order to avoid unduly cornplicating the drawings and description.

Since the credit stage relay which. newly actuated on each pulse of the nie-.ster relay is actuated on the closing of the master relay, since the previously actuated credit stage relay `is not snorted out until the restoration oi the master relay to normal, one of the signal circuit relays 2E, Sii or 32 will be in a closed condition upon the operation of the master relay by the pushing of any of the push buttons i'l as long as there remains a credit in the system. While the actuation of these relays is too rapid for the eye to see, nevertheless the time is more 'ian adequate to accomplish the functions of the circuit.

In some locations it desired to only three operations of the machine for a 25o coin and one operation for .a lee coin. order to peirnit such operation without revising the presently described system, a switching circuit is provided as indicated in dotted lines at the upper portion of Fig. l. By this arrangement, when the switch handle indicated in dotted lines i3d is in the position illustrated in Fig. l, the circuit will operate as previously described. By moving switchhandle |35 -sovasrto connect contactimem- 8. bers las and |39 of switchr It, contact members iii@ and ld! of `switch Il, and contact members E42 and it of switch |2, at the same time disconnecting contact members l 38 and Hill of switch El?, lli!) and it of switch Il, and |42 and |45 of switch l2, it will be noted that on closing of switch it by the insertion of a 25 coin a circuit is completed from the negative line conductor (l2 through the conductor 63 through the switch iii to a conductor M8, thence through the coil of relay 2t to the positive line conductor ci). This closes the relay 2Q on the operation of switch ld instead of the relay 2l.

With relay 29 thus closed, on the rst actuation of a selector button Il, relay 3Q will be closed and relay 2S will be opened. The circuit then continues through two more stages of operation by closing oi relays Si and 32 successively, as previously described. lThus, for a 25 coin but three operations of the selector signal circuit are permitted. On the insertion of a 10c coin a circuit will be completed in a similar manner through a conductor it@ and the coil of the relay :il to the positive side of the line. When thus established the actuation of but one selector button li will exhaust the credit ofthe system.

Switch l2 is not connected to any actuating circuit with this alternative arrangement, and the 5c coin slot (not shown) should be closedoff by suitable means.

While we have illustrated and described a prei'erred embodiment or our invention, it will be apparent to those familiar with the art that numerous modifications and changes may -be made without departing from our invention. It is desired, therefore, not to limit the invention except as specifically set forth in the following claims.

We claim:

l. ln a coin controlled credit system, a source of direct current, a normally closed capacitance circuit connected to said source, a normally open signal circuit, a master relay, a normally open master relay energizing circuit including the capacitance of said capacitance circuit, a manually operable selector means operable to close a selected switch in said signal circuit, to disconnect said capacitance from said source and to close said master relay energizing circuit to momentarily energize the master relay, a plurality of credit relays including a nrst credit relay, coin controlled switch means for selectively initially energizing a credit relay, a holding circuit for each credit relay closed by energization of the relay, a normally open credit relay energizing circult for each but said rst credit relay, means operated by the energization of a preceding adjacent credit relay and said master relay to complete the energizing circuit for a given credit relay, and a shorting circuit for each credit relay closable by deenergization of the master relay and energization of a -successive credit relay, said snorting circuit including a normally open switch closable by energization of the successive credit relay and a normally closed switch openable by energization of said master relay, said signal circuit including a normally open credit relay operated switch means associated with certain or" said credit relays and closable upon energization of one of said certain relays and a normally open switch controlled by said master relay,vsaid last two switches and the switch operable by the manually operable selector means completing said signal circuit.

2. In a coin controlled credit system, a source of direct current, a normally closed capacitance circuit connected to said source, a normally open signal circuit, a master relay, a normally open master relay energizing circuit including the capacitance of said capacitance circuit, manually operable selective switch means operable to close a selected switch in said signal circuit, to disconnect said capacitance from said source and to close said master relay energizing circuit for momentarily energizing the master relay, a first and a second credit relay, a coin controlled switch and circuit means for initially energizing the first credit relay, a holding circuit for each credit relay, an energizing circuit for the second credit relay including a normally open switch controlled by said first credit relay and a normally open switch controlled by said master relay and adapted to be completed by closure of said switches, a shorting circuit for each of said credit relays including a normally open switch means closable by energization of said second relay and including a normally closed switch controlled by said master relay, said signal circuit including a normally open switch controlled by one of said credit relays and closable by energization thereof and a normally open switch controlled by said master relay, said signal circuit being completed by the closing of the last-two-mentioned switches and operation of said manually operable selective switch means.

3. In a coin controlled credit system, a source of direct current, a normally closed capacitance circuit, a master relay, a normally open master relay energizing circuit including the capacitance of said capacitance circuit, manually operable selective switch means operable to close a selected switch in said signal circuit, to disconnect said capacitance from said source and to close said master relay energizing circuit for momentarily energizing the master relay, a rst, a second and a third credit relay, `a iirst coin controlled switch and circuit means for initially energizing said first credit relay, a second coin controlled switch and circuit means for initially energizing said second credit relay, a holding circuit for each credit relay, an auxiliary energizing circuit for the second credit relay including a normally open switch controlled by said first credit relay and a normally open switch controlled by said master relay and adapted to be completed by closure of said switches, an energizing circuit for the third credit relay including a normally open switch controlled by said second credit relay and a normally open switch controlled by said master relay and adapted to be completed by closure of said switches, a iirst shorting circuit for said first credit relay including a normally open switch associated with the second credit relay closable upon energization thereof and a. normally closed switch controlled by said master relay, and a shorting circuit for said second and third credit relays including a normally open switch -associated with each of said second and third credit relays closable upon energization thereof and a normally closed switch controlled by said master relay, said signal circuit including a normally open first signal switch controlled by said iirst credit relay and a normally open second signal switch controlled by said third credit relay, said signal switches being in parallel, said signal circuit including a normally open signal switch controlled by said master relay, said signal circuit being completed by closing of said last-mentioned signal switch, closing 10 of either said first or second signal switches and operation of said manually operable selective switch means.

4. In an electrical system providing a plurality of successively operable operating relays for controlling a given circuit or circuits, a source of direct current, a normally closed capacitance circuit connected to said source, a master relay, a normally open master relay energizing circuit including the capacitance of said capacitance circuit, manually operable switch means operable to disconnect said capacitance from said source and to close said master relay energizing circuit for momentarily energizing the master relay, a plurality of operating relays including a first operating relay, switch means for selectively initially energizing an operating relay, a holding circuit for each operating relay closed by energization of the relay, a normally open operating relay energizing circuit for each but said first operating relay, means operated by the energization of a preceding adjacent credit relay and said master relay to complete the energizing circuit for a given credit relay, and a shorting circuit for each operating relay closable by deenergization of the master relay and energization of a successive operating relay, said shorting circuit including a normally open switch closable by energization of the successive operating relay and a normally closed switch openable by energization of said master relay.

5. In an electrical system providing a plurality of successively operable operating relays for controlling a given circuit, a source of current, a master relay, a plurality of operating relays including a first operating relay, means including a manually operable switch for only momentarily energizing the master relay at will, means including a switch for initially energizing a selected one of certain of said operating relays, a holding circuit for each operating relay, energizing circuits for all but said first operating relay, means operated by the energization of a preceding adjacent credit relay and said master relay to complete the energizing circuit for a given credit relay, and a shorting circuit for each operating relay, said shorting circuit including a normally open switch closed by energization of a successive operating relay and a normally closed switch openable by energization of said master relay.

6. An electrical system as set forth in claim 5 in which the given circuit to be controlled includes a normally open switch controlled by the master relay, normally open switches connected in parallel and associated with certain of said operating relays, and a manually operable normally open switch.

ROBERT L. ARMOR. HARRY I. WINSLOW.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,039,988 Molina Oct. 1, 1912 2,325,536 Osborne July 27, 1943 2,331,590 Andres Oct. 12, 1943 2,388,595 Boyajian Nov. 6, 1945 FOREIGN PATENTS Number Country Date 198,135 Great Britain May 31, 1923 216,304 Great Britain May 29, 1924

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