US2271104A - Coin testing device - Google Patents

Description

Jan. 27,- 1942. P. STARKEY- I 2,271,104

' COIN TESTING DEVICE Filed May 4, 1939 2 Sheets-Sheet 1 //7 ran tor.- Lewz's P Starkey Attorney Jan. 27, 1942.

i L. P. STARKEY COIN TESTING- DEVICE 2 Sheets-Sheet 2 Filed May 4, 1959 Patented Jan. 27, 1942 UNITED STATES PATENT oFn e com TESTING DEVICE Lewis P. Starkey, Larimer County, 0010. Application May 4, 1939, Serial No. 271,775

4 Claims. (or. 1941-100) This invention relates to improvements in means and methods for separating silver coins from slugs or tokens made from other metal.

It is the object of this invention to produce a simple and effective means for separating silver coins from coins of other metal by the combined action of gravity and electrodynamic forces produced by variable magnetic fluxes.

It is well known that when disks of metal, for example, silver coins or slugs or tokens made of metal or metallic compositions are moved through an alternating or pulsating electromagnetic field, there is developed within the metal what is termed eddy currents which vary in strength substantially in accordance with the electrical properties of the metal. These eddy currents and the electromagnetic field that produces them, react on each other in an electrodynamic manner to retard and even prevent the passage of the coin through the field. Coins or disks having W resistance are retarded to a greater extent than those of equal size having higher electrical resistivity. Coins or disks having equal diameters are retarded directly in proportion to their thick-' V ness, providing they are made from the same metal, and coins or disks of equal diameter and equal thickness are retraded directly in proportion to their conductivity. It has also been found that other things being equal, coins or disks of large diameter are retarded to a greater extent than similar coins or disks of smaller diameter, because they take a longer time to pass through the magnetic field.

Circular disks or coins that are permitted to roll down an incline plane, possess at the beginning a potential energy which is converted into kinetic energy of motion when the coin starts rolling and since the kinetic energy varies with the square of the velocity and is equal to the square of the velocity multiplies by one-half of the mass, it follows that coins of the same size and material in rolling down an incline plane a given distance will attain a velocity which depends on the extent of the inclination as well as on the specific gravity of the material. If coins through the magnetic flux, while an aluminum or copper coin of the same size will be stopped by the interaction of the magnetic flux and the magnetic currents. The method employed for separating coins in accordance with this invention is to allow them to roll downwardly along an-inclined track with one side in contact with a An alternatingplane inclined to the vertical. current magnet is positioned on the under side of the inclined plane and produces an alternating magnetic field through which the coins: must pass, on their way down the track. The inclination of the track, the strength of the field and the inclinations of the non-magnetic plane are adjusted so that a silver coin will barely pass, while a copper or aluminum coin will be unable to pass through the flux and will remain stationary until the magnet is deenergized. After the silver'coin has passed through the flux or through the center of the magnetic field, the repulsive forces produced will cause the silver coin to run off of the track and *drop into a coin receptacle. A copper or aluminum'coin on the other hand will be stopped by the flux as above stated, and when released, will roll along the track into a receptacle provided for rejected coins.

Having thus briefly described the invention, the apparatus employed will now be described in de- 7 tail and for this purpose reference will be had to the accompanying drawings in which:

Figure 1 is a front elevation of the apparatus employed in the above described method;

Figure 2 is a side elevation looking in the direction of arrow 2, in Figure 1;

Figure 6 is a side view similar to that shown in Figure 2, but drawn to twice the scale, parts being broken away to better show the construction;

Figure 7 is a section taken on line 1-'!, Figure 6; and

Figure 8 is a diagrammatic view showing the circuit connections.

The apparatus which will now be described is intended primarily for use with coin controlled gasoline dispensing devices, but may be used for any other purpose where a coin control vending device is desired. The apparatus consists of a plate I 0, which may be made of iron, or any other edge formed by two inclined sides I I and I2. The bottom of the plate has an opening I3 for the reception of a pivot pin and the top has another opening I4 for the reception of a clamping bolt by means of which its position can be adjusted along a curved slot I5 in a supporting frame. The object of this adjustment will appear as the description proceeds.

In the drawings an apparatus has been illustrated that has three separate coin testing devices, one designed for silver dollars, the other for half dollars and the third for quarters. All of the devices are constructed in the same manner and dilTer only to the extent necessary to test coins of different sizes and therefore a description of one of these devices is sufiicient for all of them. Attached to the rear surface of plate I0 are three plates I6 which are preferably formed from copper or brass, but may be made from any nonmagnetic material, including such material as hard rubber or Bakelite. In the embodiment illustrated, however, plates I6 are made from copper and have flanges I'I that are attached-to the plate II) by rivets or other suitable means.

Referring now more particularly to Figures 6 and '7 where the parts are shown to a larger scale, it will be seen that the plates I6 are each provided'with a downwardly extending portion l8 to which attention will be directed as the description proceeds. A rectangular bar I9 which may be made from iron, steel or any other metal or composition is pivotally attached to plates I6 by means of a screw 29 which forms the pivot. Plate I6 is provided with an elongated opening 2I and a screw 22 passes through the inclined track bar I9 and serves to clamp it in adjusted position. By loosening the screw 22, the bar I9 can be tilted about its pivot so as to incline it to any extent desired. Plate I0 is provided with three slots which have been designated by letters a, b and 0, slot a being of the proper size to receive a dollar, slot 1) the proper size to receive a half dollar and slot c of the proper size to receive a quarter. In Figures 6 and '7 the plate I6 adjacent the dollar slot has been illustrated and the bottom of this slot has been designated by reference numeral 23.

It will be observed from Figure 7 that plate I6 is inclined with respect to the vertical and that the track member I9 is positioned on the upper side of the inclined plate. The inclination of plate I6 corresponds with the inclination of the slot 0. shown in Figure l. The purpose for which plates I6 are inclined is to keep the coins from rolling off from the track until they are subjected to the diverting force produced when the coins pass through the magnetic flux. When a dollar, which has been designated byreference numeral 24, is inserted through the slot, it will be deposited on the upper end of track bar I9 and will roll downwardly along the same due to the action of gravity. A spacing bar 25 is secured to plate I6 near its top and held in place by screws 26 and 21. A guide plate 29 is positioned on the outside of the track bar I9 and the spacer 25 and is secured to the latter by means of a screw 29. The front edge of the guide plate is bent at right angles so as to form a flange 30 that is secured to the plate In by rivets or other suitable means, such as spotwelding. The downwardly extending part I8 forms one side of a coin chute whose other side has been designated by reference numeral 3!. The sides I8 and .3I areconnected at their. edges by parts '32 vided for rejected coins.

and 33. If a coin or slug of the size of a dollar is inserted through the dollar slot, it will roll downwardly along the track and be deposited in a receptacle provided for the purpose which has not been shown. In order to effect a separation of spurious coins or slugs made from other metal than silver, but as of the same size as a silver dollar, an electromagnet is provided and secured to the under surface of the plate I6 in the manner shown in Figure 7. Reference numeral 34 designates the core of the electromagnet which must be laminated in order to prevent excessive heating. The solenoid or magnetizing coil has been designated by reference numeral 35 and these parts are secured to the plate I6 by means of a yoke 36 made from soft iron. In the form illustrated, yoke 36 is a soft, fiat, steel bar bent at right angles at points 37 and 38. Bolt 29 secures the end 38 of yoke member 36 in position against plate I6, while bolt 20, which serves as a pivot for the track member I9, passes through the end portion 39 of the magnetic yoke. The guide plate 28 may be made from magnetic material, such as soft iron, in which case it forms part of the magnetic circuit and provides a return path for the flux which divides, part returning to the end member 38 and the other part returning to the end member 39 of yoke 36. If guide plate 28 is made of nonmagnetic material, the flux will pass from the end of core 34 to the yoke member 36 through the air.

We will now assume that coil 35 is energized by an alternating current and that therefore an alternating magnetic field is produced through which the coin must pass while rolling down the inclined track. As soon as the coin enters the magnetic field, the rate of change of magnetic lines passing through the same sets up eddy currents in the metal and these interact with the flux to produce a force tending to stop the coin and prevent its further downward movement. If

the inclination of the track, the strength of the magnetic flux and the inclination of plate I6 are so selected that a silver coin can barely pass through the magnetic field, it will continue its movement until'its center has passed the center of the magnetic core, whereupon the forces will now tend to move it downwardly and at the same time outwardly with the result that the coin leaves the track and drops into the chute formed between sides I8 and 3|, the center of the coin following the dotted line 40. If, instead of inserting a silver dollar, a slug of the same size, but made of aluminum is inserted, the eddy currents set up therein will be sufficient to produce a retarding force that will stop it entirely and hold it until the magnet has been deenergized, whereupon it will be released and rolled downwardly along the track and into a compartment (not shown) provided for its reception. A copper slug will likewise be stopped by the forces produced by interaction of the eddy currents and the flux and when the magnet is deenergized, it will also roll down into the compartment pro- If an iron slug is inserted it will be held by the magnet until the latter is deenergized and will roll down the track in a like manner as the other slugs. If the slug is made of material having a very high resistance compared to silver, the eddy currents set up therein will be weak and the forces produced will not be sufiicient to stop the slug which will therefore continue its movement, but it will not roll off the track because the repulsive forces developedwill not be sufilcient to cause it to do other receptacle (not shown) and will travel with their centers along line 4|.

In order to prevent the insertion of coins or slugs before the magnets have been energized, a slide 42 is provided at the back of plate It, and this slide extends transversely of openings a, b and c. This slide is provided with one or more stops '43 that limit its movement in one direction and a spring 44 that tends to move it towards the right when viewed as in Figure 5. Stops 43 have been shown in Figure 5 as projections extending from the edges of plate 42, two such stops having been shown one of which has been designated by numeral 43. The stops engage the wall of the opening on plate It. From Figure 1, it will be seen that plate 42 is ,provided with notches 45 that are normally out of register with the slots a, b and 0, but can be brought into register if the slide is moved towards the right. One end of slide 42 is bent at right angles so as to form a lateral projection 46 that extends over the corresponding electromagnet and therefore when the electromagnets are energized, slide 42 will be moved towards the left when viewed as in Figure 3 and will bring the notches 45 into register with openings a, b and c, whereupon coins can be inserted. This arrangement guards against any one inserting a coin at times when the electric circuit is dead, for if this occurred, the coin would be directed to the reject receptacle (not shown) and could not be retrieved unless the latter receptacle is so arranged that access can be had to it from the outside.

In the actual construction, the device that has just been described is secured to a housing 41 which has been indicated by dotted lines in Figure 1. A door 48 is attached at one corner to a shaft 49 that serves as a pivot and when this door is in the position indicated in Figure 1, access cannot be had to the coin slots and before any coins can be inserted, the door must be turned through an angle of substantially ninety degrees to a position like that shown in Figure 8. Attached to shaft 49 is a mercury switch 50. When the door is in the position shown in Figure 1, the circuit through the switch is open, but when the doorhas been moved into position to permit access to the coin slot, the circuit. through the mercury switch is closed. The interconnection of the door 48 and the mercury switch assures that magnets 35 are energized when the machine is in position to receive coins and that the magnets are deenergized when the door is closed. In Figure 8, reference numeral 5| indicates an alternating current generator or source and this is connected by means of a conductor 52 with one terminal of the mercury switch. A conductor 53 extends from the other terminal and to this conductor one end of each magnetic coil is connected by means of a conductor 54. The other ends of the magnetic coils are connected by means of conductors 55 with conductor 56 that extends to the other terminal of the generator.

is open, the electromagnets will be connected. in parallel across the alternating current supply circuit. If the vending machine is so constructed that an electrical circuit must berclosed by the coins, suitable switches must be provided for this purpose. In Figure 5 a simplenormally open switch comprising contacts 51 and 58 is shown as supported from the bottom of the chutes through which the coins pass, and'when the coinpasses between these ;contacts,'it closes a circuit. One of ,these contacts is connectedby meansof a conductor, 59; with conductor 53. and the other by means of a conductor 60 with conductor .56. When the circuit is closed through v.either 1 one of the three switches, current is caused to flow through some electromagnetic switch 6 I that controls the operation. v

The above is merely intended as illustrative of means for effecting an operation whenever acoin has been deposited in the machine, but other. and different mechanisms for this purpose may. be employed, as the invention is directed to other features and can be used in connection with other operating means.

Having described the invention what is claimed as new is: l

l. A device for separating round silver coins from similarly shaped coins of different material comprising a vertical plate having a slot of the proper size to permit a coin to be passed through it, a plate of nonmagnetic material attached to and extending perpendicularly from the first mentioned plate in parallel relation to and adjacent the slot, a track secured to the upper surface of the inclined plate in position to receive and support a coin inserted through the slot, an electromagnet secured to the under surface of the inclined plate with its core positioned adjacent the path of the coin, a door pivoted to the first plate for movement into and out of slot closing position, a switch in series with the electromagnet, and means interconnecting the door and the switch for closing the latter when the door is in slot uncovering position and for opening the switch when the door is returned to slot covering position.

2. A device for separating round silver coins I from similarly shaped coins of different material comprising a vertical plate having a slot of the proper size to permit a coin to be passed through it, a plate of nonmagnetic material attached to and extending perpendicularly from the first mentioned plate in parallel relation to and adjacent the slot, the slot and the last named plate being vertically inclined, a track secured to the upper surface of the inclined plate in position to receive and support a coin inserted through the slot, an electromagnet secured to the under surface of the inclined plate wtih its core positioned adjacent the path of the coin, a bar mounted for longitudinal reciprocating movement along the rear surface Oflthe plate having the slot, the bar having an opening which registers with the slot in one position of the bar, spring means for urging the bar in one direction, means comprising cooperating stops for limiting the movement of the bar in response to the action of the spring, the bar having a portion thereof positioned within the range of the attraction of the magnet whereby when the electromagnet is energized the bar will be moved against the action of the spring to a position in which the opening in the bar registers with the slot whereby coins may be introduced through the slot only when the electromagnet is energized.

'3. In an electromagnetic device for testing coins and separatingjsilver coins from similarly shaped coins of diflerent material, a substantially vertical plate having an opening for the insertion of coins, a testing mechanism positioned to receive coins that have passed through the opening, said device comprising means for constraining the coins to move in a predetermined path and an alternating current electromagnet positioned adjacent the path whereby the coins must pass through the alternating flux field, a door movably associated with the vertical plate and movable into and out of slot closing position, an electric switch in series with the electromagnet, and means for interconnecting the switch and the door to close the switch when the door is moved to slot opening position and to open the switch when the door is moved to slot closing position.

4. In an electromagnetic device for testing and separating round silver coins from similarly shaped coins of different material, a substantially verticalplate having an opening for the insertion of a coin, a coin testing device positioned to receive a coin that is passed through the opening, said testing device comprising an alternating current electromagnet, a bar mounted for longitudinal reciprocating movement along the rear surface of the vertical plate, the bar having an opening positioned to register with the opening in the vertical plate when the bar is in one position, a spring means associated with the bar and the testing device for normally holding it in position to close the opening in the vertical plate, the her having a portion thereof positioned within the range of attraction of the electromagnet when the bar is in opening closing position, the attraction of the magnet serving to move the bar into opening uncovering position when the magnet is energized, whereby coins can be inserted only when the magnet is energized. LEWIS P. STARKEY.

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