COIN LEVEL DETECTOR

Abstract: A pivoted actuator 5 formed as a casting or moulding and including a curved surface 4 projects through a longitu­ dinal slot 3 in a coin tube 1 and operates as a shutter 7 which makes and breaks an electric circuit by interrupting a beam of radiation between a source 11 and a detector. Coins falling down the tube on to a stack 2 displace the actuator and the curved surface 4 prevents any risk of jamming either by a falling coin or by the stack building up from below. The fact that the actuator is formed as a resilient moulding greatly reduces the risk of deformation or damage.

Description: Starpoint Electrics Limited COIN LEVEL DETECTOR In the operation of coin operated gaming machines, otherwise known as amusement machines or fruit machines, each coin (or token) which is inserted passes down a guide into a vertical tube. The tube serves as a reservoir where coins or tokens are held for the payout in the event of a win by a machine player and are generally known as "pay-out" tubes. The diameter of the tube depends on the diameter of the coins or tokens being stored and it is necessary to monitor the level of coins or tokens in the tube. When the tube is full, the coins or tokens need to be diverted away and it is also necessary to detect when the level has fallen to such an extent that there are insufficient coins or tokens to meet a possible win. Should this low level ever be reached, a controlling micro-processor unit is programmed to place the machine in an inoperative mode. In order to detect this lower level, most pay-out tubes currently in use include a detector comprising a low operating force micro-switch which is actuated by a lever in the form of a length of wire having a nose portion in the form of a wide angled V which extends through a slot in the side of the tube into the path of the coins. The main length of the wire extends in a nearly vertical direction and in order to obtain sufficient mechanical advantage to operate the micro-switch, the lever is pivoted just below its upper end adjacent the plunger of the switch. As coins fall down the tube they engage the nose portion of the actuator, thus forcing it back and thereby operating the switch to give the necessary circuit signal. The V-shape of the nose portion is important because it is the inclination of the upper limb of the V which causes a falling coin to deflect the actuator in a lateral direction. Since the switch needs to have a low operating force the actuator is commonly made of relatively light wire which can easily become distorted. Various types of fault may result from this, of which the commonest is that the actuator becomes jammed either by a coin being deflected by the upper limb of the V and taking up a canted position on top of the static pile of coins extending up to the detector or by the upper edge of this pile engaging the lower limb of the V and exerting an upward thrust on it. Owing to the angle of the V, the engagement with the upper edge of the pile produces a reaction having a substantial component in the vertical direction with the result that the actuator is unable to clear itself from the coin path. Any jamming of the actuator, whether or not the nose portion is actually deformed causes failure to operate the micro-switch. Attempts are sometimes made to rectify the fault by bending the nose portion into what is thought to be the correct shape, but this frequently does more harm than good. According to the present invention, an actuator is used which is formed as a casting or moulding, preferable of resilient plastics material, which includes a curved surface which in use, projects into the tube so that when seen in vertical section, the edge of the tube forms a chord to the curve and the tangents at the two ends of the curve make acute angles with the edge of the tube. The fact that the curved portion makes an acute angle with the side of the tube both at the top and bottom means that as a coin strikes the top of the portion as it falls, the reaction has a major horizontal component which operates the actuator without difficulty. A similar effect occurs as the static pile builds t up from below, i.e. when it is being replenished after a large pay-out. If the coins fall in a generally vertical attitude they may miss the actuator altogether but as the pile builds up, engagement occurs with the lower edge of the curved portion which also makes an acute angle with the edge of the tube and thus produces a major horizontal component of thrust. This action is so efficient that in practice it is found that the deflection of the actuator to produce the required signal is normally caused by the build-up of the pile from beneath rather than by the downward movement of coins from above. However, the curved shape of the actuator also helps to avoid coins being canted as previously described and thus jamming the actuator. A further major improvement is obtained if, instead of operating a micro-switch as previously described, the actuator operates or serves as a shutter which produces the necessary signal by interrupting a beam of radiation between a source and a detector. Preferably the beam is interrupted when the actuator is displaced, but as an alternative, the beam may normally be blocked and allowed to fall on the detector by displacement of the actuator. When operating a micro-switch, the actuator has to be pressed back against the spring loading of the micro-switch and although this can be made very light, it is nevertheless necessary to produce an appreciable mechanical advantage to ensure foolproof operation of the switch. When merely interrupting a beam of radiation, there is no predetermined spring force at all which has to be counteracted and the actuator may be merely controlled by gravity, e.g. by provision of a counter-weight which tends to turn the actuator in a direction to cause the curved portion to extend into the tube. By appropriate choice of this counter-weight, an extremely small force can be sufficient to deflect the actuator from its position within the tube. Part of the counter-weight may then constitute the shutter which obstructs the light beam when the actuator is deflected. Level indicators for pay-out tubes are, of course, known, in which no mechanical detector is used at all, but a light beam is directed from a source on one side of a transparent tube, through the tube and onto a detector on the opposite side. Although this has the advantage of avoiding mechanical parts, it requires an extremely sensitive light source and detector and is liable to errors caused by dirt or flaws on the tube. In a system in accordance with the present invention, however, the light source and detector can be situated extremely close together with only the shutter opposite or adjacent them so that the most elementary and low cost components can be used and, moreover, there is no risk of errors arising from dirt on the tube. Since both the light source and detector are on the same side of the tube, the electronic circuitry can be concentrated at one location to form a self-contained unit which can be fastened to one side of the tube and which can be used for a variety of tube sizes dependent on the value of the coins or tokens being stored. In order to allow a single design of unit to be used for a wide range of tube sizes, an adapter may be inserted between the unit and the tube. It is found, in practice, that the surface of the adapter need not be a very exact match to the cylindrical surface of the tube and that as few as three different adapters may be sufficient for the whole range of tube sizes normally encountered in practice. An example of a system in accordance with the invention using a self contained unit and an adaptor for fitting to a pay-out tube will now be described in more detail, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a vertical sectional view showing a unit secured to the side of a pay-out tube with an actuator in its freely suspended or unoperated condition and the operated condition shown in dotted lines; and Figure 2 is a part-sectional plan view corresponding to Figure 1. Turning first to Figure 1, a pay-out tube 1 is shown with a stack of coins 2 at its lower end. The tube 1 is formed on one side with a slot 3 through which extends a curved portion 4 of an actuator 5. The actuator is freely pivoted at 6 at a point almost level with the top of the slot 3. As shown in full lines, the actuator 5 is freely suspended, the weight of the portion to the right of the pivot 6, including the curved portion 4 being balanced by a counter-weight portion 7. The actuator 5 is formed as a moulding of a resilient plastics material such as acetal. This is relatively simple to mould and, although resilient, maintains its dimensional stability without danger of being permanently deformed. In this respect, it is far superior to a component made of wire since, in the unlikely event of any permanent damage, it is necessary to replace the component completely and there is no possibility of attempting to restate it to its correct shape. As long as the pile of coins extends above the level of the actuator, the actuator is held in the dotted line position, but as soon as the level of the coins falls to the point illustrated in Figure 1, the counter-weight 7 causes the actuator to swing into the full line position. In this position, the curved portion 4 extends into the path of coins falling down the tube 1 so that unless an individual coin falls in a vertical attitude to the right of the actuator, the actuator 5 is temporarily displaced to the left for the passage of each coin, thus moving in a clockwise direction about its pivot 6 and producing a brief control signal. Although it would be possible for the actuator 5 to operate a sensitive micro-switch, the preferred operation, as illustrated, is by the interruption of a beam of light or other radiation indicated as 10. The interruption is achieved by a shutter formed by part of the counter-weight in its dotted line position 7'. As can be seen, particularly from Figure 1, the side of the tube 1 forms a chord to the arc constituted by the cureved portion 4 and at both the upper and lower ends of this chord, i.e. where the curved portion intersects the wall of the tube 1, the tangents make acute angles with the wall of the tube so that as a falling coin strikes the upper end, the major component of the reaction is horizontal so as to produce a clockwise turning movement about the pivot 6 into the dotted line position. Similarly, as the pile 2 builds up to a point where it engages the lower end of the curved portion 4, there is a similar horizontal thrust, producing a clockwise turning moment about the pivot 6, thus avoiding any danger of jamming. The beam of light 10 seen in Figure 2 is generated by a light source 11, such as a light emitting diode, and is received by a detector 12,.for example a photo-transistor/photo Darlington. The light source and the detector are mounted very close together with only the shutter formed by the counterweight 7 between them so that quite simple and low cost components can be used and there is no danger of the beam becoming blocked by dirt or for other reasons. The actuator 5 together with the light source and the detector forms a self-contained unit indicated as 20. This includes a housing 21 formed with a vertical slot for the passage of the actuator 5 and closed by a lid 22 which is formed integrally with the pivot assembly 6 so that the actuator 4 can be fitted in position to the lid 22 before the latter is fitted to the housing 21. The light source and the detector are moulded into a single component, and this in its turn is secured to a printed circuit board 25 which is slid into a slot from above before the lid 22 is fitted in position. The board 25 carries all the circuit components associated with the light source and detector and connectors 27 extend into an enclosure 28 forming an integral part of the top 22 and which is shaped to polarize the connector. It is therefore an extremely simple matter to connect the unit 20 into the remainder of the circuitry of the gaming machine so that signals generated as a result of interruption of the beam 10 can be processed as required. As just described, the unit 20 is completely self-contained and merely needs to be fixed to the side of the tube 1 so that the actuator 5 can extend through the slot 3. A single design of unit 20 can be used for the complete range of sizes of the tube 1, but to allow for differing diameter, an adapter in the form of a shoe 30 is included between the unit 20 and the tube 1. The unit 20 is first fixed to the selected shoe 30 by means of hooks which engage slots with a snap fit so that the unit 20 and the shoe 30 can be handled as a single component. The shoe 30 is formed with a vertical slot 33 which registers with the slot 3 in the tube 1, and has a slightly projecting rim 34 which fits into the slot 3 and thus assists in registration of the composite component. In order to secure the composite component to the tube 1, it is formed with projecting lugs 35 which are engaged by a loop of elastic material such as a thin O-ring 36. This is hooked around one lug 35, passed around the tube 1 and then hooked over the other lug 35, as seen in Figure 2, thus holding the composite component firmly in position. The face of the shoe 30 which engages the tube 1 needs to be cylindrically concave in order to match the surface of the tube, but it is found in practice that an exact match is not necessary and that only three different designs of shoe are normally sufficient for the complete range of tube sizes since the location provided by the projecting rim 34 enables -the shoe to seat snugly against the surface of the tube 1 under the resilient holding effect of the elastic loop. This very simple method of fitting means that if any fault develops in the unit 20, it can be replaced with the minimum of trouble and a fresh unit connected in position. As already described, the curved shape of the actuator 5 means that any risk of jamming is negligible, but if this is nevertheless caused, for example by a bent or damaged coin, and the actuator 5 itself becomes damaged in any way, the complete unit 20 can be replaced and there is no temptation to try to adjust the actuator 5.

Claims: CLAIMS 1. A level detector for fitting to the outside of a vertical coin tube comprising a pivoted actuator capable of projecting through a longitudinal slot in the tube when the detector is fitted in position and serving to make and break an electric circuit as a result of its pivotal movement, characterised in that the actuator is formed as a casting or moulding and including a curved surface which in use, projects into the tube so that when seen in vertical section, the edge of the tube forms a chord to the curve and the tangents at the two ends of the curve make acute angles with the edge of the tube. 2. A level detector according to claim 1 in which the actuator operates or serves as a shutter which makes and breaks the electric circuit by interrupting a beam of radiation between a source and a detector. 3. A level detector according to claim 2 in which pivotal movement of the actuator is controlled by gravity. 4. A level detector according to claim 3 in which the actuator includes a counter-weight which tends to turn the actuator in a direction to cause the curved portion to extend into the tube and part of which constitutes the shutter. 5. A level detector according to any one of claims 2 to 4 and including a housing for the radiation source and detector, an adapter for fitting between the housing and the tube and formed with a slot for registration with that in the tube and a resilient fastening for holding the housing and adapter on the tube. 6. The combination of a level detector according to any one of the preceding claims and a tube formed with a longitudinal slot for the entry of the actuator. 7. The combination according to claim 6 including a level indicator according to claim 5, in which the slot in the adapter is formed with a rim fitting into the slot in the tube.

Inventors: PARTRIDGE, DAVID
Applicants: STARPOINT ELECTRICS LIMITED
Application year: 1983
Main classification: G07D1
IPC codes: G07D1