US3317016A

US3317016A - Coin selecting device

Info

Publication number: US3317016A
Application number: US457694A
Authority: US
Inventors: Pierre P Turillon
Original assignee: International Nickel Co Inc
Current assignee: Huntington Alloys Corp
Priority date: 1965-05-21
Filing date: 1965-05-21
Publication date: 1967-05-02
Anticipated expiration: 1984-05-02
Also published as: BE679721A; GB1140232A

Description

May 2, 1967 P. P. TURILLON COIN SELECTING DEVICE 6 Sheets-Sheet 1 Filed May 21, 1965 INVENTOR. 1 164295 l /quz. 7179mm BY 'mbflmw P. P. TURILLON COIN SELECTING DEVICE May 2, 1967 May 2, 1967 P. P. TURILLON COIN SELECTING DEVICE INVENTOR. P/fiQQ HM 75(14401 6 Sheets-Sheet 4 Filed May 21, 1965 May 2, 1967 P. P. TURILLON COIN SELECTING DEVICE 6 Sheets-Sheet 5 Filed May 21, 1965 IN VENTOR.

P1617 6 @114 759mm) 7K1). HTTGPNEY y 2, 1967 P. P. TURILLON 3,317,016

COIN SELECTING DEVICE Filed May 21, 1965 6 Sheets-Sheet 6 7 V IIVENVIOR.

Y I l f? 1 /904 75 mm AITOQ/YCY United States Patent 3,317,016 COEN SELECTING DEVICE Pierre P. Turillon, Ramsey, N-L, assignor to The Internationai Nickel Company, Inc., New York, N.Y., a corporation of Delaware Filed May 21, 1965, Ser. No. 457,694 7 Claims. (Cl. 194 -100) The present invention is directed to an electronic coin selector and, more particularly, to an electronic coin selector especially capable of distinguishing coins containing a controlled amount of ferromagnetic phase from coins made of other materials.

In US. patent application Ser. No. 453,577 filed May 4, 1965 and assigned to the assignee of the present application, a special new coinage material is disclosed. This special coinage material contains no silver but is/nevertheless, interchangeable on a practical basis with silver coinage material in coin selector devices operating upon the eddy current principle. This special coinage material comprises principally a white nonmagnetic nickel alloy, for example, an alloy containing about 5% the balance nickel, and contains therein a small amount, e.g., about 0.5% to about 3%, of a ferromagnetic material, advantageously, as an inner layer of the coinage material. A satisfactory ferromagnetic material for use in this special coinage material comprises about 79%' nickel, about 5% molybdenum and the balance essentially iron. The aforementioned coin selector devices operating on the eddy current principle represent the product of many years experience in separating the standard silver alloy coinage from slug materials on the basis of the low resistivity of the standard 90% silver-% copper alloy coinage. The resistivity of the 'alloy is measured by means of a magnetic gate wherein the coin is caused to pass a permanent magnet having a field strength in the neighborhood of about 500 oersteds whereby eddy currents are generated in the coin due to magnetic induction. This effect creates a field opposing the field of the permanent magnet with the result that the silver alloy coin is slowed in its flight and is thereby directed to an accept slot. The coinage material described in US. patent application Ser. No. 453,577 is a high resistivity material and when a coin made of this material passes through the magnetic gate in eddy current generating devices, actual physical contact ensues between the coin and eddy current magnet whereby the flight of the coin past the magnet is slowed substantially to the same extent as would be a silver alloy coin of the same dimensions. Acceptance of a coin made of the special coinage material in the eddy current coin selector accordingly is to be seen to depend upon a different principle than is the case with silver alloy coinage. The principle involved is that of frictional slowing due to physical contact between the coin and the eddy current magnet. The special controlled amount of ferromagnetic phase present in the special coinage material provides therein magnetic properties, including permeability and the like, which can be precisely controlled. These magnetic properties furthermore differ materially from those of other known metallic and nonmetallic materials.

Coin selectors operating upon the eddy current principle have now been developed to a high state of perfection as a result of intensive study by competent engineers. However, since the eddy current discriminating devices are designed essentially to measure the resistivity of the coin, there is no presently known way to discriminate legitimate silver alloy coins from spurious coins having substantially the same weight and dimensions and having the same resistivity as standard coinage. For example, various combinations of copper with high resistivity materials such as stainless steel are accepted interchangeably silicon with 3,317,015 Patented May 2, 1967 "ice . with silver in these devices. Accordingly, the art of coin rejector devices based upon the eddy current principle has reached its practical limit. It does not seem possible on the basis of present information to provide coin selectors operating upon the eddy current principle which will be able to discriminate silver alloy coinage from certain copper slug materials such as, for example, a sandwich of copper and stainless steel, in the proper proportions to give a density-resistivity product approximating that of the standard silver alloy coinage.

In recent years the use of vending machines which dispense products of substantial value, which make change, and perform other sophisticated functions has been steadily increasing. Furthermore, economic factors are now such that it appears the value of products dispensed by vending machines will increase at a substantial rate with each succeeding year. This factor has made it more and more desirable to provide coin selector devices which are even more discriminating and which are more resistant to slugging by readily available materials than are devices based upon the eddy current principle. Thus, as the value of products dispensed by vending machines increases and as the adoption of devices capable of making change becomes more widespread, the problem of unscrupulous individuals obtaining products of value, or cash in the form of change, through the use of slugs having themselves no intrinsic value is steadily increasing.

I have now developed an electronic coin selector device which selects coins made of the aforementioned special coinage material from coins made of other materials with a discrimination of a high order on the basis of the special magnetic properties possessed by the material.

It is an object of the present invention to provide an electronic coin selector device capable of discriminating at a high rate of discrimination between coins having a controlled content of ferromagnetic phase and other coinage materials.

It is a further object of the present invention to provide a coin selector device which will accept only a coin containing a controlled amount of ferromagnetic phase and which is practically immune to slugging by other readily available materials.

It is another object of, the present invention to provide a coin selector device which will accept only coins made of metal having a preselected magnetic characteristic.

Other objects and advantages of the invention will become apparent from the following description taken in conjunction with the accompanying drawing in which:

FIGURE 1 is a schematic representation of apparatus contemplated in accordance with the invention;

FIGURES 2 through 8 are front elevational views of apparatus contemplated in accordance with the invention illustratingthe apparatus and its mode of operation;

FIGURE 9 is a cross-sectional view of the apparatus as depicted in FIGURE 6 at the section 9-9 depicted thereon;

FIGURE 10 is a cross-sectional view of the apparatus as depicted in FIGURE 4 at the section 10-40 depicted thereon; and

FIGURE 11 is a circuit diagram depicting circuitry appropriate for use in the coin selector device contemplated in accordance with the invention.

Broadly stated, the coin-discriminating means contemplated in accordance with the invention for discriminating coins made of a composite material comprising a nonmagnetic metal and a small controlled amount of a ferrornagnetic material comprises a coin passageway having accept and reject passages, a sensing field located in relat-ion to said passageway adapted to sense said coin and to emit a preselected signal when said coin is in sensing position, and means connected to said sensing field opin rotor 22 (FIGURE 3).

erative in response to said preselected signal to divert or direct said coin to said accept passage.

Advantageously, magnetic permeability is the property of the special coinage material containing a controlled amount of ferromagnetic phase to be sensed by the aforementioned sensing means. Accordingly, the sensing or detecting means advantageously comprises an oscillator, including a coil tuned such that insertion in the core thereof of a coin having the aforementioned property moduates the resonant frequency of the oscillator to a preselected value. The signal thus created may be amplified by convenient means connected to said oscillator and transmitted to a frequency selector device which is actuated in response to the preselected signal so as to actuate a selector device. A satisfactory device in accordance with the foregoing is depicted schematically in FIGURE 1. In FIGURE 1, reference character 11 is a coil having a core adapted to receive coin 12. Oscillator 13 is connected to coil 11. Coil 11 and oscillator 13 are tuned to create a given frequency having a value F when no metallic material is present in the core of coil 11. When a coin containing a controlled amount of ferromagnetic phase is present in the core of coil 11, the frequency of the oscillator is shifted to a preselected value F determined by the magnetic properties of the coin. Advantage-ously, the oscillator frequency is amplified by the amplifier '14 connected thereto and the amplified signal is transferred to the frequency selector device 15 which is responsive to said preselected frequency F and may, for example, be a'reed or a filter. Actuation of the frequency selector 15 completes the circuit to relay 16 and operates the selector device. Power source 17 is employed to provide the DC. power necessary to operate the device.

FIGURES 2 through 10 depict in front and side views an operative device contemplated in accordance with the invention and depict various stages in the course of its operation. The device comprises a backing plate 18 having mounted thereon front plate 19, rear plate 20, a coin slot 21, a rotor 22 tiltable in the plane of

plates

19 and 20 about eccentric pivot 23, and having a slot-like opening 22A, and a separator 24. Said coin slot 21, rotor 22,

plates

19 and 20 and separator 24 form a coin passageway having accept passage 25 and reject passage 26. Sensing coil 11 is wrapped about the portion of rotor 22 defining opening 2 2A and accordingly rotor 22 is made of a constructional material such as a plastic which does not interfere with the passage of magnetic lines of force therethrough. Rotor 22 is provided with counterbalance means 27 such that, at rest, rotor 22 is in balanced upright position about pivot 23. Leads 28 conveniently pass to circuitry mounted on the back of plate 18 through pivot 23. Magnet 29 is mounted in slot 21 to retain slugs or washers made of strongly ferromagnetic material such as steel.

The operation of the device to select a coin made of nonmagnetic metal but containing a core layer comprising a controlled proportion of a ferromagnetic material such as an alloy containing about 79% nickel, about 5% molybdenum, and the balance essentially iron, will now be described in conjunction with FIGURES 2, 3 and 4. The coin is inserted in slot 21 and, being only weakly magnetic, passes magnet 29 and drops into opening 22A As explained in conjunction with FIGURE 1, coil 11 is part of an oscillator circuit tuned such that insertion of a coin having the required amount of ferromagnetic phase in the core of coil 11 modulates the resonant frequency of the oscillator to a preselected range which actuates frequency responsive device (FIGURES 1 and 111) thereby completing the circuit to solenoid 16 and causing stop 30, connected to the solenoid armature, to be driven into the path of rotor 22. As depicted in FIGURE 4, stop 30 has been actuated as a result of the emission of the preselected signal from the oscillator and rotor 22 has been halted in its rotation above separator 24 and coin 12 has been transferred to accept passage 25. In the instance of coins which do not have the required magnetic characteristics and which do not actuate the circuitry so as to drive stop 30 forward, rotor 22 continues in its rotation until halted by fixed stop 31 and the coin is transferred to reject passage 26. In each instance as depicted in FIGURES 4 and 5, rotor 22 is returned by counterbalance means 27 to the upright position.

FIGURES 6, 7 and 8 depict the operational sequence employed when a steel slug or washer or other strongly ferromagnetic material is inserted in the device. As depicted in FIGURE 6, the slug 12 adheres to magnet 29, which is a permanent magnet having a field strength on the order of, for example, 500 oersteds. In order to clear the slug from the device, coin return means 32 provided with spring 33 is depressed. Coin return means 32 is guided by pins 34 sliding in slots 35 in front plate 19 and is connected through lever 36 pivoted at 37 to wiper blade 38 which is pivoted at 39. Coin return means 32 is also connected to rotor 22 through linkage 40, also pivoted at 39, and linkage 41 connected to rotor 22 at point 42 to provide a lever arm in relation to rotor pivot 23. Linkage 41 is connected to linkage 40 at 43. A loop is provided in linkage 41 to avoid restraint in rotation of rotor 22 when a coin is inserted in opening 22A in rotor 22. When coin return means 32 is depressed, wiper blade 38 is caused to bear against slug 12 while simultaneously rotor 22 is rotated. As shown in FIGURE 7, movement of wiper blade 38 and rotation of rotor 22 are mechanically coordinated such that by the time wiper blade 38 removes the magnetic slug from magnet 29, rotor 22 is substantially inverted and the slug falls into reject cup 44. Release of pressure upon coin return means 32 causes return of all components to the at rest or upright position as shown in FIGURE 8 under the impetus of spring 33 and counterbalance 27 and the magnetic slug is thereupon transferred to the reject passage as depicted in FIG- URE 8. It is to be seen from the figures that a cutout 45 is provided in rear plate 20 to provide clearance for lever 36 and that lever 36 is connected to part 32 by pins 36A running in

guide slots

32B and 36B.

It is further to be noted that when a coin is inserted in the device which is nonmagnetic but is made of a material such as aluminum or plastic such that it is too light to cause rotation of rotor 22, it is transferred to reject passage 26 by actuation of the coin return means. Nose 32A on part 32 covers the top of cavity 22A during rotation thereof by the coin return means so that the coin is retained in cavity 22A during actuation of the coin return means.

FIGURE 9 is a cross-sectional view taken at section 9-9 in FIGURE 6 depicting conditions at the time a strongly ferromagnetic coin or slug is inserted in slot 21 which is retained by magnet 29. Stop 30 attached to or forming part of the armature of solenoid or relay 16 is retracted since no signal has yet given, and the ferromagnetic slug must be cleared or swept from magnet 29 by actuating coin return means 32 and the linkages as sociated therewith as described hereinbefore in conjunc'- tion with FIGURES 6, 7 and 8.

FIGURE 10 is a cross-sectional view taken at section 10-10 in FIGURE 4 depicting the operation of the coin selector device at the point where the rotor 22 has been halted in its rotation by stop 30 which is attached to or forms part of the armature of solenoid or relay 16 mounted on the 'back of backing plate 18. Acceptable coin 12 is shown in accept passage 25 between

plates

19 and 20 after having rolled out of the slot-like opening 22A in rotor 22.

FIGURE 11 depicts circuitry appropriate for use in conjunction with the mechanical arrangement depicted in FIGURES 2 to 10. Oscillator 13 is tuned to the desired frequency F by means of variable inductor 46. The oscillator circuit comprises transistor 47,

condensers

48 and 49 and resistors 50, 51 and 52, connected as shown in the drawing. The signal from the oscillator circuit is amplified by amplifier 14 which represents conventional circuitry and is depicted as a two-stage

amplifier comprising stages

53 and 54 and when the preselected signal of frequency F is emitted by oscillator 13 upon insertion of a coin having proper controlled magnetic characteristics in the core of coil 11, reed 15 responsive to frequency F is actuated completing the circuit to solenoid 16 and driving the stop 30 forward so as to halt rotation of the rotor as described hereinbefore. Power supply means 17 is depicted having reference to a multiple tap rectifier provided With

leads

17A, 17B and 17C to supply power for the oscillator circuit, the amplifier, the reed relay, and the solenoid.

In order to give those skilled in the art a better appreciation of the advantages provided in accordance with the invention, the following examples will now be given:

Example I I norder to demonstrate that the frequency shift of a tuned oscillator-coil circuit due to insertion in the core of a coil of a coin-size disc made of a sandwich-type composite material comprising outer layers of an alloy containing about 95% nickel and 5% silicon with a controlled amount, i.e., about 2% by volume, of high permeability core alloy containing about 79% nickel, about 5% molybdenum and the balance essentially iron comprises the basis for a coin selector or indicator device, a test circuit was constructed, The circuit comprised a coil of 400 turns of 32 AWS gage enameled wire wrapped about a structural plastic coil form having a rectangular slot Core: Resonant frequency, c.p.s. Air 15,628 90% silver, balance copper alloy 15,796 Copper (high purity) 15,722 70% copper, 30% nickel alloy 15,637 Stainless steel (AISI 310) 15,632 80% nickel, 20% chromium alloy 15,632 Composite sandwich disc 15,490 Mild steel 14,821

The foregoing data demonstrate that the special composite coinage material described hereinbefore possesses unique properties differing from the properties of other common metallic materials and that the shift in resonant frequency of a tuned oscillator can be employed as a basis for distinguishing the special composite material from other materials. It will be noted from the foregoing data that a number of the metallic materials actually increased the resonant frequency of the oscillator whereas the special composite material reduced the resonant frequency as compared to the air core frequency. The data demonstrate that a device in accordance with the invention can be tuned to accept the standard silver alloy coinage material but a device so tuned would not accept the composite coinage material. By employing in parallel a device tuned to accept the special coinage material containing a controlled amount of ferromagnetic phase and a device tuned to accept silver coinage, both types of coinage could be accepted.

- constructed wherein the sensing coil 11 comprised 3000 turns of 38 gage AWS enameled wire wound upon a structural plastic coil form having a slot designed to accept a coin having the physical dimensions of a standard U.S. twenty-five cent piece. The structural plastic coil form had the physical appearance of rotor 22 in the drawing. The combination of oscillator 13 and coil 11 where tuned to a resonant frequency of 1500 cycles per second when a coin having the physical dimensions of a US. twentyfive cent piece made of an alloy containing nickel and 5% silicon and having a core comprising about 2% of the coin volume made of a ferromagnetic alloy containing about 79% nickel, about 5% molybdenum and the balance essentially iron was inserted in the coin receiving cavity in rotor 22. The signal from oscillator 13 was amplified and fed to a frequency selective reed relay 15 which was responsive to a frequency of 1500 cycles per second within a frequency band of plus or minus 0.5%. It was found that coins containing 2% by volume of ferromagnetic alloy were accepted by the device On the other hand, coins containing 1.8% and 2.2% of the ferromagnetic alloy but which were otherwise identical were rejected 100%. Again, common slug materials such as steel washers, zinc discs, copper discs and brass discs were rejected 100%, as were standard U.S. twentyfive cent pieces. Composites of copper and stainless steel which were accepted 100% in coin selector devices of the eddy current type along with US. twenty-five cent pieces were rejected 100% by the device contemplated in accordance with the invention. It was found that the device withstood repeated handling and transportation while retaining its highly selective characteristics. The device is fail-safe since failure of the power supply or of any electrical component results in rejection of all coins.

With further reference to the drawing, it will be appreciated thatcoil 11 is in parallel with a fixed capacitor. Accordingly, the frequency of oscillation of the field in coil 11 is inversely proportional to the square root of the inductance of coil 11. The inductance of coil 11 is essentially constant. When a metal disc containing a ferromagnetic metal is inserted in the field of coil 11, the coil acts as a iron core coil. As depicted in FIGURE 11, direct current continually passes through the coil in order to bias the transistor in the oscillator circuit. This direct current is of a low order so that power drain in the oscillator is low and can be supplied, for example, by a small capacity battery. Thus, in the apparatus depicted in the drawing, a direct current on the order of about one milliampere is satisfactory. The direct current creates a magnetizing force in the field of the coil. For satisfactory operation, this magnetizing force may be on the order of about 0.1 to about 100 oersteds, e.g., about 1 to about 30 oersteds. The amplitude of the alternating current in the coil is determined by the oscillator and is essentially constant when the coil is operating as an iron core coil. The frequency of the alternating current in the coil and oscillator changes by a small factor upon insertion of a metal disc into the coil field. The effect of frequency upon the inductance of the coil is negligible when the coil frequency is in the audio frequency range, i.e., a frequency of at least about 10 cycles but lower than 100 kilocycles per second and, advantageously, not in excess of about 50 or even about 20 kilocycles per second. Prequencies in the radio frequency range, i.e., above 100 kilocycles per second, are avoided because of the skin effect found when such frequencies are employed.

When an iron core coil is subjected to a combination of AC. and DO fields, the DC. field causes the core to be magnetized by a constant magnetizing force. In the present instance wherein the DC. field is of a low order, this magnetizing force will be at a low point on the BH curve. The AC. component of the magnetizing force will then carry a ferromagnetic c'ore through a hysteresis loop whose slope is not the same as the slope of the magnetization curve (BH curve). The slope of this hysteresis loop is the incremental permeability at a given field strength. When incremental permeability is plotted against the BH curve, the value of incremental permeability approaches a low value asymptotically as the induction B on the 'BH curve approaches a substantially constant value. In instances wherein the magnetizing force of coil 11 is so low that a ferromagnetic material inserted in the coil is not brought substantially to saturation, the incremental permeability will have a substantial value, whereas in instances wherein the magnetizing force of the coil 11 is sufficient substantially to magnetically saturate the ferromagnetic material, the incremental permeability will be of a low value. It has been found there are instances wherein a ferromagnetic material such as pure nickel will have about the same incremental permeability as will a coin made of a nonmagnetic material such as a 95% nickel-% silicon alloy and containing about 2% of a ferromagnetic alloy containing about 79% nickel, about 5% molybdenum and the balance essentially iron. However, pure nickel has a much larger saturation induction than a coin containing only about 2% of the aforementioned high permeability (ferromagnetic) alloy and would be held by magnet 29.

It is to be seen that with further reference to FIGURE 2 in the drawing that counterbalanced, pivoted rotor 22 operates as a weighing device for coins. This feature of the design contemplated in accordance with the invention provides for great simplification of the apparatus. In addition, a short delay in the passage of the coin is interposed through the use of the rotor 22 bearing the sensing coil 11 thereon which affords a response time for actuation of the frequency selector 15. In the instance of a reed relay having a frequency of oscillation of about 1560 cycles per second, a response time of about 100 milliseconds is required. Of course, other frequency selector devices characterized by more rapid action than a reed can be employed as the frequency selector device 15. Thus, a mechanical filter, a series of tuned circuits, a biased oscillator, a tuned circuit with a Q multiplier and other circuitry used in conjunction with decoding and telemetering devices may be employed as the frequency selector device. In such situations, the sensing coil 11 can be located in fixed relation to the coin passageway and other known devices for weighing and sizing coins may be employed in the coin selector unit. In addition, when the sensing coil 11 is in fixed location to the coin passageway, the coin passageway itself can take other forms from that depicted in the drawing.

The electronic circuitry provided in accordance with the invention is susceptible to miniaturization with the result that it may be manufactured on a high production basis at low cost. A further feature of the apparatus is that a material compensating effect in regard to temperature is achieved thereby. Thus, for example, when the ambient temperature increases, the frequency of oscillation in oscillator circuit 13 decreases. However, the magnetic permeability of the coinage material to be selected also decreases with temperature increase and this factor results in an increase in the frequency of the oscillator circuit. Of course, if desired, additional temperature compensating means may be supplied.

It is also to be appreciated that the selector mechanism 16 may take other forms which avoid the use of moving parts in the coin selector mechanism. Thus, where appropriate power supply is available, the selector mechanism can be an electromagnet operative in response to a signal from frequency selector device 16. In such an event, the coin passageway can be provided with appropriate tracks or chutes for accept and reject passages. It is to be understood that coins containing a controlled small proportion of ferromagnetic material (usually not more than about 3% by volume, of the coinage material) will be attracted to a magnet having a field strength of about 500 oersteds but will not adhere thereto. This attribute of the special coinage material selected by the mechanism contemplated in accordance with the invention enables shunting of the special selected coins toward the magnet to an accept passage under the impetus of a magnet whereas coins and slugs made of nonmagnetic material continue in their path unaffected by the magnet and are rejected.

It is further to be appreciated that relay or solenoid 16 can be operatively connected to a myriad of indicating or signalling devices, including switches, lights, audible alarms, cameras and other devices which may be employed to signal and/or record the fact that a spurious coin has been deposited in a coin collecting, coin sorting or coin-operated device. For example, in a highway toll collecting device, the apparatus provided in accordance with the invention could be connected such that a signal light remained red upon deposit of a spurious coin or slug but turned green upon deposit of a coin containing a controlled amount of ferromagnetic phase. Similarly, in coin sorting devices the presence of a spurious coin in a series of coins could be signalled by appropriate means upon passage of the coins through or past the sensing coil.

Although the present invention has been described in conjunction with preferred embodiments, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention, as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the invention and appended claims.

I claim:

1. In a coin selector device, the combination for selecting a coin having a controlled magnetic property comprising a coin passageway, an oscillator including a coil about said passageway tuned to provide a resonant audio frequency when said coil has an air core and to provide a modulated resonant audio frequency when said coin forms the core of said coil, a frequency selective device responsive to said modulated audio frequency from said oscillator and selector means responsive to said frequency selective device adjacent said passageway to select said coin.

2. A coin selector device according to claim 1 wherein the frequency selective device is a reed.

3. A coin selector device according to claim 1 wherein the frequency selective device is a filter.

4. A coin selector device according to claim 1 wherein said frequencies do not exceed about 50 kilocycles.

5. In a coin selector device, the combination for selecting a coin comprised essentially of nonmagnetic metal but containing a small controlled amount of a ferromagnetic phase insufficient to cause said coin to cling to a permanent magnet but sufficient to cause physical contact bet-ween said coin and a permanent magnet having a field strength of about 500 oersteds when said coin is caused to pass said magnet comprising a coin passageway, an alternating current sensing field oscillating at a resonant frequency in the audio range adjacent said pas sageway, said sensing field being modulated to a different resonant frequency in the audio range when said coin containing a ferromagnetic phase is in sensing relation to said field, and means operative in response to said modulated audio frequency from said sensing field to select said coin and to reject coins which do not similarly modulate said oscillating sensing field.

6. In a coin selector device, the combination for selecting a coin comprised essentially of nonmagnetic metal but containing a small controlled amount of a ferromagnetic phase insufficient to cause said coin to cling to a permanent magnet but sufficient to cause physical contact between said coin and a permanent magnet having a field strength of about 500 oersteds when said coin is caused to pass said magnet comprising a coin passageway, a permanent magnet adjacent said passageway to stop ferromagnetic coins, a rotor bearing a coin-holding cup in said passageway and accept and reject passages in said passageway beyond said rotor, a coil wrapped about said coinholding cup, said rotor being balanced so as to be tipped by insertion in the coin-holding cup therein of a coin having the denomination being selected, said coil forming part of an oscillator circuit tuned to emit a preselected signal in the audio frequency range when said coin containing a ferromagnetic phase is inserted therein, a frequency selective device responsive to said preselected signal, and selector means responsive to said frequency selective device to direct said coin to said accept passage.

7. In a coin selector device, the combination for selecting a coin of a given denomination made of a nonmagnetic nickel alloy and containing an inner layer of a ferromagnetic alloy in a controlled amount such that said coin is attracted by a permanent magnet having a field strength of the order of 500 oersteds but does not adhere thereto which comprises mechanical means including a coin passageway, a permanent magnet adjacent the entrance of said coin passageway, a rotor interposed in said passageway and accept and reject passages in said passageway past said rotor, interconnected mechanical means for rotating said rotor from an upright to an inverted position and for wiping the surface of said magnet, a first cup mounted upon said rotor interposed in said coin passageway when said rotor is in said upright position and a second cup mounted upon said rotor interposed in said coin passageway when said rotor is in said inverted position, said rotor being rotatable by gravity when said coin is in said first cup, a sensing coil about said first cup, an oscillator connected to said sensing coil tuned to emit a signal having a preselected frequency in the audio range when said coin containing said controlled amount of ferromagnetic alloy is in said first cup, a frequency selective device responsive to said signal having said preselected frequency from said oscillator and operative in response to said signal to actuate a relay, and a stop actuated by said relay to halt the rotation of said rotor to transfer said coin from said first cup to said accept passage.

References Cited by the Examiner UNITED STATES PATENTS 2,304,996 12/1942 Gebert et al 194-101 2,642,974 6/1953 Ogle 194100 2,918,158 12/1959 Shlank 194-100 X FOREIGN PATENTS 451,694 1936 Great Britain.

ROBERT B. REEVES, Primary Examiner.

STANLEY H. TOLLBERG, Examiner.

Edward M. Fletcher, Jr.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,317,016 May 2, 1967 Pierre P. Turillon It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line 10, for "moduates" read modulates line 70, after "device" insert l5 column 5, line 21, for "I norder" read In order Signed and sealed this 21st day of November 1967.

(SEAL) Attest:

EDWARD J. BRENNER Attesting Officer Commissioner of Patents

Claims

1. IN A COIN SELECTOR DEVICE, THE COMBINATION FOR SE LECTING A COIN HAVING A CONTROLLED MAGNETIC PROPERTY COMPRISING A COIN PASSAGEWAY, AN OSCILLATOR INCLUDING A COIL ABOUT SAID PASSAGEWAY TUNED TO PROVIDE A RESONANT AUDIO FREQUENCY WHEN SAID COIL HAS AN AIR CORE AND TO PROVIDE A MODULATED RESONANT AUDIO FREQUENCY WHEN SAID COIN FORMS THE CORE OF SAID COIL, A FREQUENCY SELECTIVE DEVICE RESPONSIVE TO SAID MODULATED AUDIO FREQUENCY FROM SAID OSCILLATOR AND SELECTOR MEANS RESPONSIVE TO SAID FREQUENCY SELECTIVE DEVICE ADJACENT SAID PASSAGEWAY TO SELECT SAID COIN.