US2288014A - Device for the automatic detection of genuine coins - Google Patents

Description

June 30, 1942. .1. F. MULLEN ETAL 2,288,014

DEVICE FOR THE AUTOMATIC PETECTION OF GENUINE COINS Filed Jan. 12, 1940 3 Sheets-Sheet l June 30, 1942. l J. F. MULLEN ETAL DEVICE FOR THE AUTOMATIC DETECTION OF GENUINE COINS 3 SheetS Sheet 2 Filed Jan. 12, 1940 I NVE N TORY c/Zmes F/kd/exr Wnd F growls ATToR Yi June 3 1941 AL 2,283,014

DEVICE FOR THE AUTOMATIC DETECTION OF GENUINE COINS Filed Jan. 12, 1940 s Sheets-Sheet s Many very clever and ingenious coin a slug of a baser metal I a great other than one of Patented June 30, 1942 navrcii son James F. Mullen, Rive Dearborn, Mi

Brooks,

THE AUTOMATlC DETECTION OF GENUINE COINS r Rouge, and Wendell B.

ch., assignors to Electric SlugBeiector and Manufacturing Corporation, a corporation of Missouri Application January 12, 1940, Serial No. 313,550

4 Claims.

This invention relates to improvements in that type of devices which is adapted. to be used in connection with various types of automatic coin operated machines and employed for the auto-- matic detection and rejection of slugs of baser' metals than the coin by which the machine is intended to be actuated While it has been found that slugs having the same dimensions as a genuine coin, but constructed of baser metals, can be very readily detected by the use of thermo-electric or electro-chemical means for contact with the slug upon its insertion in the device, and although many attempts have been made to devise automatic coin detectors of this general type, as far as we are aware, none oi these devices that have been heretofore suggested have been entirely successful.

expedients are resorted to by the type of people whom we will designate generally as the unscrupulous to beat" coin actuated machines. One of the common expedients in the slot of a coin controlled machine which is capable of actuating erly and. to insert immediately after the genuine which, iollowing immediately after the genuine coin, will result in a double actuation of the machine because of the lag in the thermo-electric or electro-chemv ical detecting mechanism.

As far as we are aware, no one has heretofore made available a coin detecting device capable present invention;

is that of inserting a genuine coin the electrical device prop- I panying drawings forming a part hereof and wherein:

Fig. l is a diagrammatic view in section showing. the coin chute of a coin detector with a diagram of the electrical circuits associated therewith; Fig. la is a diagrammatic view indicating the manner in which a relay may be connected in an electrical circuit of the coin detector for completing a circuit to a main machine; Fig. 2 is a side elevation of a coin detecting device constructed in accordance withthe principles of the Fig. 3 is a vertical cross-sectional view through the coin chute of the device shown in Fig. 2; Fig. 4 is a rear view of the device with the casing partly removed; Fig. 5 is a side view of the lower portion of the structure shown in Fig. 4 as seen from the right hand side thereof; Fig. 6 is a section along the line 6-6 of Fig. 5; Fig. '7 is a fragmentary cross section taken on the line 1-1 of Fig. 2; Fig. 8 is IO trode is connected by a wire 20a with a galvanometer type relay switch 23, while the elecof operating with sufilcient accuracy to safeguard the operation of the main machine against all of the more common expedientsemployed by the unscrupulous. Consequently, none of the coin detecting devices heretofore proposed have ever gone into general use, although there has been demand for devices of this character and although the losses resulting .from the improper practices of the unscrupulous reach in the aggregate to quite considerable sums of money.

One of the principal objects of this invention, therefore, is to provide a coin detecting device in which there will beassociated, in combination, means for preventing the-actuation of a main machine by a spurious coin. I

It will be understood that throughout the foltrode 2| is similarly connected to said galvanom eter by means of a wire 21a.

In the form shown in Fig. l the electrode 20 8 is adapted to be heated by a heating coil 36 connected directly to a main source of either A. C.

or.D. C. electricity by means of connecting wires 366, Nb. Whena coin is inserted into the coin slot of the coin chute 22, it will, if the coin is 40 of the proper diameter, make contact with the lowing description we will employ the term I the connecting wires 20a and 2m and the gelspurious coin electrodes 20, 2| and due to the fact that the electrode 20 is heated while the electrode 2! is cold, a thermoelectrical eflect will be produced in accordance with the well-known characteristics of devices of this character, causing an electromotive force of small magnitude to b'e'generated in what may be termed the primary actuatingcircuit of the device, this circuit consisting of the electrodes 20, 2|, the inserted coin,

vanometer type relay 23.

The galvanometer 23 is of standard construction, including a galvanometer needle 32, which carries a movable switch contact 33 adapted, upon acertain amount of deflection oi the nee- .cuit will be referred to as the dle 32, to make contact with a fixed contact 34. The needle 32 may be so adjusted that it will be deflected an amount just sufficient to cause the contacts 33 and 34 to be closed only when a genuine coin is in contact with the electrodes 20, 2|.

Due to the fact that galvanometer types of switches, sufllciently sensitive to react to the presence of a-minute el-ectromotive force such as is induced in the actuating circuit of the device, are of necessity very light and delicate mechanisms, the use of a galvanometer switch to carry the full load of the main electrical circuit of the device has proven to be one of the serious causes of difficulty with the accuracy of coin detecting devices as heretofore constructed due to arcing, pitting and sticking of the galvanometer switch contacts. Therefore means are incorporated in the present invention to employ the galvanometer switch only momentarily and to relieve such switch of the necessity for carrying the larger currents employed for actuating the coin detector. I

The needle 32 of the galvanometer is connected by a connector 3211 to one terminal of thecoil of a solenoid 39 while the other terminal of said coil is connected by a connector 39a to the main line 36a at some suitable point, such as-indicated at 35; a pair of switch contacts 31, 38' being interposed in the connector 390 for a purpose presently to be described. The fixed contact 34 of the galvanometer switch is connected by a conductor 34a to the main line 36b at any suitable point 42, so that when the switch contacts 33, 34 are closed, current from the main source of electricity is established to the solenoid 39 through a circuit consisting of the connector 390, the connector 32a, galvanometer contacts 33, 34 and the connectors 34a. This cirsecondary actuating circuit of the device.

The solenoid 39 is provided with a movable core 43 in accordance with the usual construction of such devices.

In order to relieve the galvanometer' switch contacts of carrying the entire load and to avoid objectionable pitting and arcing of the switch contacts 33, 34, the solenoid core' 43 has associated with it a pair of switch contacts 48, 49;

the manner in which such switch contacts are mechanically associated with the solenoid core 43 being shown in Fig. 6 of the drawings.

Mounted in insulating material below the solenoid 39 there is a pair of spring conductors l6 and 11 upon which the contacts 48 and 49 are mounted. A plunger consisting of a shaft 18 and a head 19 is attached to the movable core 43 of the solenoid so that the shaft portion 18 projects through holes provided in the spring conductors I5 and 11. Hence, when the solenoid 39 is energized, the core 43 will be caused to move to the left from its position shown in Fig. 6, carrying the plunger with it, so that the head 19 of the plunger will engage the spring conduc tor l1 and bend it to the left toward the spring conductor 16. This movement will result in the completion of an electrical circuit across the con- 7 tacts 48 and 49, which circuit will be maintained as long as the solenoid 39 remains energized. As.

soon as the solenoid is de-energized, the force holding the core 43 to the left of its position of Fig. 5 will no longer exist, whereupon the spring conductor 11 will resume its normal position by reason of its inherent resiliency, thus breaking the circuit across the contacts 48 and 49 and also returning the core 43 to the position shown in Fig. 6.

By reference to Fig. 1 it will be seen that the switch contacts 48, 49 are arranged in a shunt circuit connected across the conductors 32a, 340 between points 46 and 41 thereon by wires 49a and 48a respectively, so that when the switch contacts 48, 49 are closed upon the energization of the solenoid 39 by the closing of the secondary actuating circuit, current from the main source of electricity flowing to the solenoid coil 39 will be shunted, or by-passed, around the galvanometer 23 and its switch contacts 33, 34, through the shunt circuit which includes the switchcontacts 48, 49. The circuit so formed, extending from the main line 360 through the conductor 39a, the solenoid 39, the conductor 32a to point 46 thereon, the conductor 49a, switch contacts 49 and 48, conductors 48c and 34a to the main line 36b, will hereafter be referred to l as the work circuit of the device.

As will be seen by reference to the diagrammatic showing of Fig. 1 of thedrawings-and also by reference to Figs. .2 and 3, the coinchute 22 adjacent to its lower. end is provided with a pair of branch chutes, or outlets, 44 and 45, the branch chute 45 leading to a coin box (not shown) for retention of the genuine coins, while the branch 44 is a rejector chute through which the spurious coins are deflected to prevent actuation of the main machine by such spurious coins. The branching of the coin chute to form the delivery branches 44, 45 is arrangedso that the entrance to the rejector chute 44 is immediately below, and in vertical alignment with, the main coin chute 22, in order that a coin inserted in the main chute'22 will normally fall by gravitydirectly into the branch chute 44. The entrance to the'branchchute 45 which leads to the coinbox is in effect formed in the vertical side wall of the chute 22; and, as clearly indicated in the drawings, the location of the solenoid 39 tranceto the branch chute 44 "so es to obstruct this entrance. When the core 4 3 is caused to be projected into the coin chute through the energization of the solenoid, the coin dropped into the chute 22 will strike the end of the core 43 and will be deflected laterally into the genuine coin chute 45 to be delivered thereby to a coin box.

Located adjacent the exit of the branch coin chute 45 is a normally closed cut-off switch comprising -a .pair of switch contacts 40, 4| and shown=diagrammatically in Fig. 1 as interposed in the connector 34a between the points 41 and 42 thereof. The actual construction 'of .this switch is shown best in Fig. 7, and it consistsof a fixed contact 4| and a movable contact 48 mounted on the lower end of a leaf spring 48a,

the spring 40a being adapted-to hold the mov- 50 so arranged that a genuine coin traveling through the coin chute 45 will pass between the cam surface 50 and the opposed wall of the chute 45 causing the block 5| to be moved outwardly of the chute against the action of the spring 49a so as to break the circuit between the contacts 48, 4|, and thus interrupt the passage of current through the work circuit to the solenoid 39. The

so as to establish a primary actuating circuit, cult which, in addition to the electrodes 28 and and then without releasing the coin to permit 26 and the coin 24, consists of wires 29 and 20 it to travel into the coin chute, to withdraw it leading to a galvanometer relay 3|. Thus the ac- Means for preventing this is incorporated in from the coin slot. type of fraudulent operation the circuit of the solenoid 39 and consists of having a pair of spring contacts 21, 32; the spring contact 38 being a fixed one and the contact 31 a movable contact mounted at one end of a resilient arm pivoted intermediate its ends and having a spring 1i associated with it for the purpose of normally holding the movable contact 31 in engagement with the fixed contact 38. The resilient arm 10, as shown in the'diagrammatic view of Fig. l, is arranged closely adjacent'to the electrodes 20, 2| at the entrance to the coin chute, so as to project across the chute at one side thereof and to be spaced from the other side of the chute a distance slightly less than the diameter of the coin for which the chute is designed. As a result of this construction, when a coin of the proper diameter is inserted into the coin chute one side of the coin will engage the free end of the arm 10. As the coin is pushed past the free end of the arm 10 the arm will be flexed slightly to permit the coins passage and will also tend to be moved in a counter-clockwise direction so as to press the contact members 31 and 38 into tighter contacting engagement. After the coin has been inserted into the coin chute far enough to produce contact between the electrodes 20, 2|, if an attempt should then be made to withdraw the coin,

the free end of the arm 10 and move the-same in a clockwise direction against the action of the spring Ii to break the contact between the members 31 and 38, thus interrupting the flow of ourrent to the solenoid.

to actuate the.

v ance wire is provided.

the coin on being pulled outwardly from the coin chute will again engage tuation of the secondary actuating circuit connected through this galvanometer is produced in substantially the same mannerr-as hereinbefore described in connection with the thermo-electric type of primary actuating circuit.

As shown in Fig. 9 a variant form of thermoelectric primary actuating circuit is. employed which is designed to eliminate the necessity for the continuous operation 0! the heating coil 36 which has previously been described. In the modified form shown in Fig. 9 a connector having a coin contacting loop 52 of high resist- The loop 52' projects into the coin chute so as to contact a coin, indicated diagrammatically at 53, the inherent flexibility of the wire being employed for maintaining the contacts of switch 54 normally out of engage ment. When the coin is inserted into the coin chute between the loop 52 and a cold electrode i2l, the pressure of the coin against the loop 52 will cause the switch 54 to be closed. An instantaneous heating of the loop 52 will then result, due to its high resistance; The electromo-- tive force thereby produced then flows through the circuit including'wires 51a and 520 leading to a galvanometer 56. A choke coil 55 is preferably provided in this actuating circuit of the relay to insure that only the thermo-electrically induced electromotive force reaches the galvanometer.

While we are aware that the use of thermal electric effects to operate a relay and in turn a solenoid operated coin detector have heretofore type relay provided pair of spaced coin contacts in said circuit adapted when bridged by a genuine coin,*to cause said been suggested, we make no claim broadly to such elements in combination but claim our improvements in devices of this type. as follows.

J We claimr 1. In a coin detecting device, a primary actu-- ating control circuit including a galvanometer with a pair of contacts, a

j relay to be energized, a coin selector including a.

coin chute, and a secondary actuating circuit for actuatihg sa'id selector including a solenoid, con- *nections thereto from a main source of elec- We have found, after extensive experimentation, that the eiiiciency of the thermo-electric primary actuating circuits of coin detecting devices depends very largelyupon the material used for the coin detecting electrodes, and that nichrome and copper are preferable for the hot and cold electrodes, respectively, with the hot electrode being maintained at a temperature of about 500 F. For silver coins the electro-chemical type of primary actuating circuit as shown diagrammatically in Fig. 8 is preferably employed, in which case by analogy to the thermoelectric circuit of Fig. 1, an electrode 25 corresponds to the electrode 20 while in place of the hot electrode 24 a wick 26 is immersed in an electrolyte 21 and is urged into contact with the coin 24 by action of a suitable spring 28. When a coin 24 is inserted into the chute so as to contact with the electrodes 25 and 26, a primary actuating circuit is completed, and by the combination of the silver coin and the electrolyte (which is acetic acid) in this circuit, electrochemical eiiects are produced resulting in the generation of an electro-motive force in this cirtricity through said relay and a-work circuit in shunt with said relay contacts having a normal- 1y open switch therein mounted adjacent to said solenoid and coin selector to be closed by said solenoid immediately said solenoid is caused to be actuated by the presence of a genuine coin in said primary circuit, thereby to maintain current through said work circuit around said gaivanometer contacts directly to said solenoid from said main source of electricity, a normally closed switch in said work circuit and means projecting into said coin chute beyond said coin selector to cause said normally closed switch to be opened by the passage of a genuine coin after said coin has passed said selector, thereby to interrupt the flow of current to said solenoid.

2. In a coin detecting device, a primary actuating control circuit including a galvanometer type relay provided with a pair of contacts, a pair of spaced coin contacts in said circuit adapted when bridged by a genuine coin, to cause said relay to be energized, a coin selector including a coin chute, and a secondary actuating circuit for actuating said selector including a solenoid, connections thereto from a main source of electricitythroughsaid relay and a work circuit.

device is thereby ie-energized so that it is ready to receive the next coin.

As coin detecting devices of the. type herein disclosed are generally used for the actuation of what we have termed a main machine, which in turn is electrically operated, we have indicated in Fig. la the manner in which such a main machine may be actuated upon the insertion of a genuine coin in the coin detecting device. The means employed for thispurpose, as shown in Fig. la, consists of a solenoid switch 13 interposed in the connector 34a between the points 14-15 so that when current passes through the connector 24:: the solenoid 13 will close the switch 80 in the electrical circuit 8| supplying power to the main machine.

The manner in which the parts, as heretofore described, operate is as follows: When a coin is inserted in the coin slot at the entrance of the main coin chute 22 it bridges across the electrodes 20, 2 I, the electrode 2| being normally held by the action of a spring 51 at a distance from the electrode 20 slightly less than the diameter of a genuine coin of the type by which the ma-' chine is intended to be operated, and the electrode 20 being heated-by the coil 36 while the electrode 2| remains unheated. The thermoelectric effects will cause an electromotive force to be induced in the primary actuating circuit.

- If the coin is of the proper metallic composition of a genuine coin, the electromotive force so generated will cause the galvanometer needle 32 to be moved the requisite distance to closethe contacts 33-, I4 and current will then flow in the secondary actuating circuit from the main line 36a through the connector 39a, through the coil of the solenoid 39, connectors 32a, switch contacts 83, 34 and connector 34a to the other main line 36b, the switches 31, 38 and 40, 4| being normally closed. If the coin that was inserted is a genuine coin, the actuation of the solenoid 39 causes the solenoid core 43 to be projected into the coin will not be projected into the coin chute; therefore, the coin will drop by gravity immediately into the rejector branch chute 44.

One of the more common expedients adopted by the unscrupulous to defraud a coin operated machine where such machine is protected by a coin detector is to insert first a genuine coin immediately followed by a spurious one, thereby to take advantage of the lag of theelectrically operated coin detectors heretofore employed.

The detector of the present invention has incorporated in its construction means for effectively preventing this type of petty larceny, which, of course, is only efiective against a main machine which is actuated by the coin after the same has passed through the detecting device, and is not effective where the main machine is actuated by the actuation of the detecting device in the manner described herein and shown in Fig. 1a. This means consists of a novel arrangement and careful positioning of the solenoid actuated coin detector with respect to the cut-out switch 40, 4|.

As can be seen from an inspection of the showing of Fig. 2, the block 5|, which causes the contacts 40 and 4| of the cut-ofi switch to be separated upon the passage of a coin through the branch coin chute 45, is placed a very short distance from the junction of the branch coin chute 45 and the main coin chute 22 so that two coins cannot be simultaneously contained within the coin chute 45 with the device remaining actuated. Theoretically, at least, this means that chute 22 at the entrance of the branch chute. 44, 7

thus causing the genuine coin to be deflected into thebranch chute "leading to the coin box.

The instant the current flows in the secondary actuating circuit to produce an actuation of the solenoid 39, the switch 48, 49 in the work circuit will be closed immediately, thus causing the current from the main line to be shunted'around the l J galvanometer 23 throughthe work circuit, immediately relieving the galvanometer from performing any further function until the primary actuating circuit is again closed by the insertion of another genuine coin, and providing for the continuous energization of the device from a steady source of supply rather than relying upon the small current momentarily induced in the pri- -mary actuating circuit forthis purpose, thereby,

.insuring the retention'of the genuine coin by the the distance between the center of the solenoid core .43, and that point along the cam face 50 of the block 5| at which a passing coin causes sufiicient displacement of the block 5| to break the circuit across the contacts 40 and 4|, must be less than one and one-half times the diameter of the coins being tested. r

. a This distance is designated as theoretical because other factors present in the operation of the device of the present invention make it practically impossible. for one successively inserted coins to follow another so closely that their edges would contact. Due to the fact that the electrode 2| is ,spring held and as the contacting faces of both the electrodes 20, 2| are either wedge-shaped or conical, thespringpressure of the electrodes against an entering coin tends to retard the passage of the coin somewhat until it has been pushed into the'coin slot far enough to bring the full diameter of the coin across and in contact with the electrodes at which time the wedgeshape of the electrodes and the spring pressure device. As the geneuine coin passes through the V I branch chute 4? it engages the inclined cam surface 50 and moves the block 5| against the action of the spring 40a to break the contact between the switch contacts 40,- thus cutting of! the work circuit to the solenoid. The solenoid core 43 will therefore be withdrawn from the coin chute and contactbetween the switch contacts 48, 49 is then broken. If the coin inserted in the coin chute is spurious rather than genuine, the

' electromotive force generated in the primary actuating circuit will not be sufficient to close the galvanometer switch contacts 33, 34. Hence the secondary actuating circuit will not be closed, the solenoid 39 will not be actuated and the core 43 tends to give the coin a marked acceleration into the coin chute. In other words, while the passage of one coin through the device is being accelerated, the passage of a following coin is being retarded; and therefore, if a genuine coin is first inserted into the coin slot, its passage along the coin chute 22 to the solenoid core 43 and thence to the cut-out switch 40, 4| is bound to occur before an immediately following spurious .coin can be inserted past the electrodes .and travel the distance along the coin chute to the location of the solenoid core. Therefore, the passage of the first genuine coin will cause a deenergization of the device before a following coin, whether genuine or spurious, can reach the solenoid, core and be retained; and as a result, the following coin will be rejected.

Another expedient frequently'employed to defraud coin operated machines is to insert a genu ine coin far enough into the coin slot to produce contact thereof with the coin detecting electrodes closed switch to be opened by genuine coin past said selector,

aasaou in shunt with said relay contacts having a norreally open switch therein mounted adjacent to said solenoid and coin selector to be closed by said solenoid immediately said solenoid is caused to be actuated by the presence a genuine coin in said primary circuit, thereby to maintain cur rent through said vanometer contacts directly to said solenoid from said main source of electricity, a normally closed switch in said work circuit and means for actuating the same projecting into said coin chute beyond said coin selector for causing said normally the passage of a said means being spaced from said coin selector a distance relative to the diameter of a genuine which 'the'device is designed that the interruption oi current to said solenoid will be insured by the passage of a genuine coin past said selector before a second coin can travel in said coin chute past said selector.

3. In a coin detecting device, a primary actuating control circuit including a galvanometer type relay provided with a pair of contacts, a pair of spaced coin contacts in said circuit adapted when bridged by a genuine coin, to cause said relay to be energized, a coin selector including a coin chute, and a secondary actuating circuit for actuating said selector including a solenoid, connections thereto from a main source of electricity through said relay and a work circuit in shunt with said relay contacts having a normally open switch therein mounted adjacent to said solenoid and coin selector to be closed by said solenoid immediately said solenoid is caused to be actuated by the presence of a genuine coin in said primary work circuit around said galcircuit, thereby to maintain current through said work circuit around said galvanometer contacts directly to said solenoid from said main source of electricity, a normally closed switch in said work circuit and means for actuating the same proiecting into said coin chute beyond said selector for causing said normally closed switch to be opened by the passage of a genuine coin past said selector, said means being spaced from said coin selector a distance relative to the diameter 0! a genuine coin oi the type for which the device is designed to be actuated and said distance being substantially-less than the distance between said pair of coin contacts and said coin selector, whereby the interruption oi current to said solenoid will be insured by the passage of a genuine coin past said selector before a second coin can travel in said coin chute past said selector.

4. In a coin-detecting device, a coin chute, a

coin selector in said coin chute, a circuit controlling the energization of said coin selector, a pair of spaced contacts in said coin chute and connected in said circuit adapted when bridged by a genuine coin through said circuit, a normally closed switch in said circuit and resilient means for actuating said switch located to the entrance of said coin chute and adjacent to said pair of contacts adapted to yield to permit the insertion of a coin into said chute to engage said contacts and when engaged by a coin withdrawn irons said coin chute to open said switch.

JAMES F. sacrum. wnnnnmi R. BROOKS.

Images