EP0629979A2 - Coin tester - Google Patents

Abstract

The invention relates to a testing device for round discs (4, 11, 13), for example coins, in which the discs (4, 11, 13) run along at least one gauge on a guide (15, 23, 41) supporting them. The testing devices known hitherto have only a limited throughput on account of their construction. Moreover, they are very expensive in terms of production. The invention avoids these disadvantages by delivering the round discs (4, 11, 13) onto an inclined slip plane (6), down which they slip and over which extends at least one collecting rail (7, 10) which is inclined relative to the horizontal and which collects the discs (4, 11, 13) and diverts them to the side. The discs (4, 11, 13) are thereafter fed to an optoelectronic device for the measurement of diameter and/or thickness. This combination allows considerably higher throughputs than in the testing devices known hitherto. <IMAGE>

Description

The invention relates to a test device for round disks, preferably of the same dimensions, in which the disks run on a guide supporting them on the circumference and on at least one side along at least one gauge. To the extent that we are talking about disks here and in the following, it means round or polygonal disks, round disks, possibly with a raised rim, embossed coins, washers or similar technical disks.

Test devices of this type are used to check coins or coin blanks in various processing stages for dimensional accuracy, in particular with regard to diameter, thickness, roundness and flatness, as well as completeness of the shape. So far, these tests have been carried out directly in front of or behind the machine performing the individual processing step, for example a coin press. Since such presses currently work with stroke rates of less than 1000 strokes per minute, the previously known test devices, with their mechanical gauges and calibres in particular, are still sufficient in terms of performance.

However, it is disadvantageous that each individual machine must be provided with its own test device, which, due to the high precision with which the gauges must be manufactured, significantly increases the price of the machine. It would be beneficial here to be able to operate several presses together with just one test device. However, the performance of the known test devices is not sufficient for this. In addition, the test accuracy leaves something to be desired.

The object of the present invention is therefore to provide a test device with which a considerably higher throughput can be achieved. This test device should be reliable, low-wear and easy to convert to other disc dimensions.

This object is achieved in that the guide is preceded by an inclined sliding plane, onto which the panes can be placed horizontally from above, and over which at least one collecting rail inclined relative to the horizontal runs into the guide at its lower end.

The invention has the advantage that a large amount can be picked up and processed by the test device, essentially disordered slices. The coins slide under their own weight down the inclined plane and are caught by the inclined collecting rail from the vertical movement and diverted to the side. If the number of arriving disks increases so that the catch rail can no longer pick up all the disks and remove them to the side, the disks start to roll over and jump over the catch rail. they then fall back onto the inclined slide level and can be caught there by an additional rail, which may be fitted for these excess panes, and then also removed to the side.

The panes, which are also not caught by the second rail, then fall into an overflow channel at the lower end of the slide level, from which they are fed back onto the inclined slide level from above via a conveyor device.

The discs picked up by the collecting rail start to roll due to the lateral inclination of the collecting rails, which causes the high throughput of the test device according to the invention.

In order for the round disks to slide and roll as high a throughput as possible, it is advantageous if the slide plane is inclined between 10 ° and 70 ° with respect to the vertical, or the collecting rail between 10 ° and 60 ° with respect to the horizontal. A particularly even throughput is achieved with an inclination of the sliding plane of approximately 25 ° and an inclination of the catch rail of approximately 30 °.

In addition, it is advantageous if the collecting rail has a thickness that is smaller than the radius but larger than the thickness of the disks. In this way it can be achieved that many panes are gripped and those panes which tip over when they hit the collecting rail fall over the collecting rail and do not hinder the rapid rolling of the remaining panes.

Otherwise, the collecting rail can have a separating section at the lower end, which has a thickness less than or equal to the pane thickness. If two slices roll down the collecting rail directly next to one another, the separating section causes these two slices to be separated and only one continues to run on the collecting rail while the other falls away downwards.

Since the collecting rail is matched to the dimensions of the disks in terms of their thickness, it is expedient to attach them to the slide level in a detachable and interchangeable manner, or adjustable to the respective coin dimensions. This ensures that the device can be easily converted to round disks of various dimensions.

Otherwise, the catch rail can have cutouts on its side facing the sliding plane, so that dirt carried by the round disks can fall behind the rail and thus do not impair the smooth running of the round disks.

In addition, pneumatically controlled blowing nozzles are provided in the area of the collecting rails, which are controlled at intervals to remove the dirt that builds up.

The slice separated in the separating section then runs through a test station.

In the known test stations, the coin runs through a series of gauges and calibres through slots or holes are formed. In order for these gauges and calibres to work reliably and to safely separate individual disks with missing dimensions from the total quantity, the total current past these gauges cannot be very high. In order to be able to guarantee the desired throughput numbers in the case of a diameter gauge, a diameter gauge according to the invention has two strips of light-sensitive elements which are arranged on one side of the disc plane essentially parallel to it in such a way that at least one of the strips runs essentially along the guide. In addition, this diameter gauge according to the invention has a light source which is arranged on the opposite side of the disk plane and throws parallel light onto the light-sensitive elements. The round disks rolling along the guide cast a shadow on the light-sensitive elements, which generate corresponding signals that are processed by an evaluation unit.

It is particularly advantageous if one bar is parallel to the part of the guide which supports the disks on the circumference and the other is arranged approximately at right angles to the first bar. In this case, the diameter can be calculated in a particularly simple manner from the end points of the shadow cast by the pane onto the strips of light-sensitive elements. But even if the strips of light-sensitive elements are parallel or at any angle to one another, the diameter of the disk passing by can be determined from the end points mentioned.

Either the light source can emit flashes of light or the light-sensitive elements record their signals only briefly; which prevents the shadow from smearing during the optical integration time due to the disk movement.

It is also advantageous if the height between the part of the guide which supports the disks on the circumference and the bar of photosensitive elements running parallel to this is less than 4/5 of the disk diameter. This ensures that discrete measured values are obtained without a grinding cut.

If the gauge integrated in the test device is a thickness gauge, it can have at least one measuring system, which consists of a bar of optoelectronic, light-sensitive elements, which is arranged above or below the guide perpendicular to the plane of the pane, and a on the other side of the guide, a bar of several light sources arranged parallel to the first bar, which throw parallel light onto the photosensitive elements via imaging optics and an evaluation unit which processes the signals generated by the photosensitive elements. Since the parallel light bundles generated by these light sources are each angularly offset from one another, they radiate around the disk, which casts a shadow in each of the light bundles, the width of which is detected by the light-sensitive elements. If the pane is tilted relative to one of these bundles of light, the measured width is enlarged compared to the actual width. Only the slightest measured width of the disc coincides with the actual. In this way, a wobbling movement of the disk to be measured can be compensated. In order to separate the individual parallel beams so that a defined width statement can be made, it is best to flash the individual light sources one after the other and to read and evaluate the result in the bar of light-sensitive elements.

Instead of a bar with singular light-sensitive detectors, a single continuous detector can be used, which works analog. Likewise, the detectors can also be arranged in areas, in particular in a polar coordinate system.

In the area of the lateral delimitation of the panes, the parallel light bundles must be able to reach the light-sensitive elements unhindered, apart from these panes themselves. For this it is necessary to provide suitable recesses in the slide level and the guide.

In order to obtain a faster measurement or redundancy of several measurements, the thickness gauge can have at least two measuring systems arranged at an angle to one another.

In order that disks in which an incorrect dimension has been determined are sorted out, it is expedient for the testing device to have an ejection unit at the end of one or more gauges, the ejection unit in one embodiment according to the invention Is air nozzle, which is arranged in the region of the part of the guide supporting the disc on the side. A blast of air through this nozzle can push a disk past it from the running rail, so that it falls into a reject collection shaft assigned to the ejection unit. The ejection can expediently also take place by means of electromagnets generating eddy current. Otherwise, the tour ends in a collecting shaft for "good" slices, from where the slices can be fed to a further processing step or to the final inspection or packaging.

Fiugr 1

eine erfindungsgemäße Prüfvorrichtung;

Figur 2

Prinzipskizze einer erfindungsgemäßen Durchmesserlehre;

Figur 3

die Schaltskizze einer erfindungsgemäßen Durchmesserlehre;

Figur 4a, 4b

Prinzipskizze einer erfindungsgemäßen Dickenlehre.

Figur 5

Dickenlehre mit mehreren Meßsystemen

Die Figur 1 zeigt eine erfindungsgemäße Prüfvorrichtung. Die zu prüfenden runden oder polygonen Scheiben, bei denen es sich um ausgestanzte Ronden, um Ronden mit aufgestauchtem Rand oder eine fertig geprägte Münze handeln kann, ebenso um Unterlagscheiben oder andere technische Scheiben, liegen ungeordnet in einem Schüttkegel 1 auf einer Schwingrinne 2. Diese Schwingrinne wird in bekannter Weise durch einen Schwingantrieb 3 in leichte Vibrationen versetzt, so daß sich die Scheiben 4 aus dem Schüttkegel 1 herauslösen und im wesentlichen nebeneinanderliegend über Übergangsbleche 5 auf eine Rutschebene 6 gleiten. Diese Rutschebene 6 ist etwa 25° gegenüber der Lotrechten geneigt.Further features and advantages of the invention result from the following description of an exemplary embodiment. It shows

Fiugr 1

a test device according to the invention;

Figure 2

Principle sketch of a diameter gauge according to the invention;

Figure 3

the circuit diagram of a diameter gauge according to the invention;

Figure 4a, 4b

Schematic diagram of a thickness gauge according to the invention.

Figure 5

Thickness gauge with several measuring systems

1 shows a test device according to the invention. The round or polygonal disks to be tested, which can be punched-out blanks, blanks with a raised rim or a finished coin, as well as washers or other technical disks, are disordered in a pouring cone 1 on a vibrating trough 2. This vibrating trough is set in a known manner by a vibratory drive 3 in slight vibrations, so that the disks 4 detach from the cone 1 and slide essentially side by side over transition plates 5 on a sliding plane 6. This slide plane 6 is inclined approximately 25 ° with respect to the vertical.

The disks 4 slide down this slide level 6 until they meet a catch rail 7 which is arranged on the slide level 6 at a laterally inclined position.

On this catch rail 7, the disks 4 change from the sliding to the rolling state and roll the catch rail 7 laterally downward, as shown by the arrow 8. There are panes that are not held by the collecting rail 7 for a variety of reasons. These jump over the catch rail 7 by, for example, overturning (arrow 9).

They then land again on the slide level 6 and can accordingly roll sideways on a second collecting rail 10, which is fastened below and parallel to the collecting rail 7 on the slide level 6.

Discs 11, which are not held by the second collecting rail 10, fall into an overflow channel 12, from which they are transported back into the vibrating channel 2 via a conveyor device, not shown.

In the case of the disks running along the collecting rails 7, 10, two disks (13) may run directly next to one another. So that this does not come in at the same time the gauges or calibres connected downstream of the collecting rail, the collecting rails 7, 10 have, at their lower end, singling sections 14 which have the thickness of a single disk.

Discs that roll down the collecting rails 7, 10 directly on the slide level 6 continue to roll on the singling sections, while disks that run alongside these first disks get the support down in the singling section and also fall into the overflow channel 12, from where out of it again on the vibrating channel 2 and then the slide level 6 are transported.

After the disks have been separated in the manner described, they roll or slide past a diameter gauge 16 and a thickness gauge 17 indicated only by the coordinate crosses for their sorting on a guide 15. Should it be determined in these teachings that the diameter or the thickness of the disc being tested does not correspond to the target values, then an air blast is imparted to the discs via air nozzles 18 which are installed in the slide plane 6 at the end of the gauges 16, 17 that they fall from the guide 15 into a committee collecting shaft 19. Otherwise, the disks run to the end of the guide 15 and can be fed there to the next processing stage or the final inspection, etc.

Auch durch eine Ausgleichsberechnung kann der Mittelpunkt bestimmt werden. Dabei gilt

Da gilt

erhält man zwei Gleichungen für die unbekannten X_M und Y_M.The principle of the diameter gauge 16 results from FIGS. 2 and 3: FIG. 3 shows how a light source 20 parallel light 21 on a disc 22 throws, which runs along a guide 23 in front of two strips of light-sensitive elements 24, 25. These strips 24, 25 are shown in more detail in FIG. 2. The bar 24 runs at a constant distance Ŷ to the guide 23 and the bar 25 runs at a right angle to it at the point X̂. Due to the shadow cast by the disc 22 onto the strips 24, 25, the points X₀ and X₁ as well as Y₀ and Y₁ result. The position of the center point can be calculated directly from this:

The center point can also be determined by a compensation calculation. The following applies

Since it applies

you get two equations for the unknown X _M and Y _M.

Otherwise applies to both center point calculations

All four values r₀₀ to r₁₁ must match the specified radius of the disk up to predetermined tolerances, otherwise the disk 22 is blown by the air nozzle 26 from the guide 23 when the position X _D is reached.

The strips 24 and 25 can either be arranged directly behind the panes 22 such that the panes 22 cast a shadow on the strips 24 and 25. Alternatively, the disks 22 can be imaged on the strips 24 and 25 with the aid of a lens.

The individual parts from which the diameter gauge is composed are shown in FIG. 3.

The strips of light-sensitive elements 24 and 25, which can be CCD strips, are controlled by a driver 27. The signals of the strips 24, 25 generated by the parallel light 21 are then converted by an analog-digital converter 28 and fed to a computer with signal processor 29. This computer 29 also contains an interface circuit 30, with which a light source driver 31 is controlled, which controls the light source 20. The light source 20 emits flashes of light of such a length of time that the signal picked up by the CCD strips is not unduly blurred.

A programmable controller 32 is coupled to the computer with the signal processor and has a monitor 33 and a keyboard 34, via which it can be programmed. The programmable controller 32 controls a valve driver 35 with which a valve 36 is to be opened, through which compressed air 37 is passed through the air nozzle 26, which functions in the manner described above.

A similar control exists for the thickness measurement, the function of which is outlined in FIG. 4: light is cast from a light source 38 through a lens 39, the lens 39 making the light parallel. This parallel light strikes a disc 40 which runs on a guide 41. As a result, the pane 40 casts a shadow 42 on a bar of light-sensitive elements 43 which is perpendicular to the plane of the pane. The thickness of the pane 40 can thus be determined by evaluating the signals emitted by the light-sensitive elements. In FIG. 4b, light which is emitted by the light 39 from a light source 44 which is adjacent to the light source 38 is inclined onto the pane 40 as parallel light. This results in a wider shadow 45 on the bar more sensitive to light Elements 43. In the event that the disk 40 tumbles, it would not cast the thinnest shadow through the light source 38, as shown, but through the light source 44, so that the effective thickness of the disk can be determined even with a tumbling disk. The shadow can be cast onto the bar of light-sensitive elements 43 either directly or via a lens.

FIG. 5 shows that several thickness measuring systems of the type just described can also be arranged at different angles α, β to the guide 41, so that the disk 40 is measured by several thickness measuring systems at the same time. If the disk is not within the required thickness tolerance, it is pushed into the reject collection shaft 19 by the guide 41 as already described for the diameter gauge.

In summary, the invention specifies a possibility of contactlessly testing a large number of disks or disk-like objects or of treating them in another way, as a result of which piece numbers can be achieved which were previously not possible.

Claims (23)

Test device for round disks or the like, in which the disks run along at least one gauge on a guide supporting them on the circumference and on at least one side,
characterized,
that the guide (15, 23, 41) is preceded by an inclined sliding plane (6) onto which the disks (4, 11, 13) can be placed lying down from above and via which at least one collecting rail (7, 10) inclined with respect to the horizontal runs, which merges into the guide (15, 23, 41) at its lower end. Device according to claim 1,
characterized,
that the sliding plane (6) is inclined between 10 ° and 70 °, in particular approximately 25 °, with respect to the vertical. Device according to claim 1,
characterized,
that the catch rail (7, 10) is inclined between 10 ° and 60 °, in particular approximately 30 °, with respect to the horizontal. Device according to claim 1,
characterized,
that the catch rail (7, 10) has a thickness which is smaller than the radius and greater than the thickness of the disks (4, 11, 13). Device according to claim 1,
characterized,
that a separating section (14) is arranged behind the collecting rail (7, 10) at the lower end, which has a thickness less than or equal to the disk thickness. Device according to claim 5,
characterized,
that the separating section (14) is adjustable transversely to the slide plane (6). Device according to claim 1,
characterized,
that the catch rail (7, 10) is detachably and interchangeably attached to the slide level (6). Device according to claim 1,
characterized,
that the catch rail has cutouts on its side facing the sliding plane. Device according to claim 1,
characterized by
that the sliding plane (6) in the area of the collecting rail (7, 10) has pneumatically controlled blowing nozzles. Device according to claim 1,
characterized,
that the slide level (6) has an overflow channel (12) at its lower end. Device in particular according to claim 1,
characterized,
that the teaching is a diameter gauge (16) and has the following components - On a surface or along two rows (24, 25) of photosensitive elements which are arranged on one side of the disk plane substantially parallel to this in such a way that at least one of the rows (24, 25) substantially along the guide (23) runs. - And a light source (20) which is arranged on the opposite side of the disk plane and throws light (21) on the light-sensitive elements (24, 25) - And an evaluation unit (29) which processes the signals generated by the light-sensitive elements (24, 25). Device according to claim 11,
characterized,
that one row (24) is parallel to the part of the guide (23) which supports the disks on the circumference and the other bar (25) is arranged approximately at right angles to the first bar (24). Device according to claim 11,
characterized,
that the light source (20) emits flashes of light. Device according to claim 11,
characterized,
that the light-sensitive elements (24, 25) emit signals intermittently. Device according to claim 11,
characterized,
that the height between the one row (24) and the part of the guide 23 which supports the disks on the circumference is less than four fifths of the disk diameter. Device in particular according to claim 1,
characterized,
that the gauge is a thickness gauge (17) and has at least one measuring system that contains the following components a surface or a row (43) of photosensitive elements which is arranged above or below the guide (41) essentially perpendicular to the plane of the pane, - And one on the other side of the guide (41) parallel to the first surface or row arranged surface or row of several light sources (38, 44), which throw parallel light onto the photosensitive elements (43) - And an evaluation unit that processes the signals generated by the photosensitive elements (43). Device according to claim 16,
characterized,
that only one of the several light sources (44, 38) emits lightning-like light. Device according to claim 16,
characterized,
that the washers laterally supporting guide parts (6) have recesses in the area between the light-sensitive elements (43) and the light sources (44, 38) and that the guiding part (41) supporting the washers (40) on the circumference is tapered in thickness in this area. Device according to claim 16,
characterized,
that the thickness gauge (17) has at least two measuring systems arranged at an angle to one another. Device according to claim 11 or 16,
characterized,
that the test device has an ejection unit which is arranged at the end of the gauge (16, 17). Device according to claim 20,
characterized,
that the ejection unit is an eddy current generating magnet or an air nozzle (18, 26) which is arranged in the region of the part (6) of the guide supporting the disk (22, 14). Device according to claim 20,
characterized,
that the ejection unit is assigned a committee collecting shaft (19). Device according to claim 1,
characterized,
that the guide ends in a collecting shaft for "good" discs.

Images