EP2192561A1 - Method and device for determining the diameter of coins in a freefall coin device - Google Patents

Abstract

The method involves spacing two light beams (LS1,LS2) traverse to a coin (22) in a drop direction. The diameter (m) of the coin is calculated corresponding to the formula. A starting signal is generated from an inductive sensor provided in the drop direction of the coins. A starting signal is generated by the coins during entry into the former light beam. An independent claim is included for a device for determining the diameter of different coins.

Description

The invention relates to a method for determining the diameter of different coins in a free fall coin device according to claim 1.

Conventional coin validators have a track along which coins roll along after the throw. On their way to the track, they are tested for authenticity with the help of one or more probes. When authenticated, they pass through a switch in a cash register or a Münztube a coin store. If the authenticity check is negative, the coin is directed into the return channel.

Increasingly, so-called free fall coins are used. In these coins fall a certain distance above a Münzweiche or the like. Free-fall coins have the advantage that the coins move faster than conventional devices. Checking the coins for authenticity in a free-fall coin device requires special precautions.

An authenticity criterion for coins is their diameter. Conventional coin validators are therefore equipped with a measuring device for the diameter determination. It is known to perform a diameter test by inductive means with appropriate measuring coils. However, it is also known to provide for the diameter test photocells. On the one hand, with the help of the light barriers, a time measurement is made to determine the time that a coin goes through a certain distance during its fall. In addition, the speed of the coin is measured to calculate the diameter from these two values. Such a provision is approximately in US 6,053,300 and US 6,467,604 B1 described. The known coin dispensers have two spaced in the direction of the coin photocells, in US 6,467,604 B1 between the the first and second light barrier, an inductive sensor is arranged and the distance between the first and second sensor is greater than the distance between the second and third sensor. In US 6,053,300 It is described that the diameter is calculated from the time difference between leaving the coin of the first light barrier and leaving the coin of the third light barrier. A reference to the immersion of the coin in the first photocell is expressly excluded.

If in the prior art, the departure of the coin of the last photocell is used to determine the diameter, this means that the underlying Münzweiche has at least a distance from the third photocell, which is greater than the diameter of the largest coin to be accepted. This means that the entire fall path is relatively long in the known device, which has a corresponding height of the coin unit result.

The invention has for its object to provide a method and apparatus for determining the diameter of different coins in a free fall coin device, which requires only a small overall height of the coin device.

This object is achieved by the method claims 1 and 2 and by the device claim 6.

In the method according to claim 1 according to the invention, a starting signal is preferably first generated by the inserted coins. If photocells are used, the generation of a start signal is obligatory if an accurate diameter determination is to be carried out. Because a light barrier is preferably not operated in continuous operation, but is turned on when a coin check is pending. For the invention, a start signal is not mandatory.

wobei d der Abstand der Lichtschranken, T2 der Zeitpunkt, an dem eine Münze die erste Lichtschranke verlässt, T3 der Zeitpunkt, an dem die Münze in die zweite Lichtschranke eintaucht und a₀ die Erdbeschleunigung ist.In the method according to the invention, the coins traverse only two light barriers in succession, the diameter m being calculated according to the following formula: $$\mathrm{m}\mathrm{=}\mathrm{d\; T}\mathrm{2}\mathrm{/}\mathrm{T}\mathrm{3}\mathrm{+}\mathrm{½}{\mathrm{a}}_{\mathrm{0}}\mathrm{t}\mathrm{2}\left(\mathrm{T}\mathrm{2}\mathrm{-}\mathrm{T}\mathrm{3}\right)$$

where d is the distance of the light barriers, T2 the time at which a coin leaves the first light barrier, T3 the time at which the coin is immersed in the second light barrier and a _{0 is} the gravitational acceleration.

In the solution according to method claim 2 also only two light barriers are provided, and the start signal is also to be generated. The diameter m is calculated according to the following formula: $$\mathrm{m}\mathrm{=}\mathrm{d}\left(1-\mathrm{T}\mathrm{3}\mathrm{/}\mathrm{T}\mathrm{4}\right)\mathrm{+}\mathrm{½}{\mathrm{a}}_{\mathrm{0}}\left(\mathrm{T}\mathrm{3}\times \mathrm{T}\mathrm{4}-{\mathrm{T}3}^2\right)$$

The sizes given in this formula are already defined above, where T4 is the time at which the coins leave the second photocell.

In the method according to the invention, only two light barriers are required, thus already for this reason the overall height is relatively low. In addition, the distance between the light barriers need not be particularly large. It can be smaller than the smallest coin to be accepted. Of course, this distance can not be made arbitrarily small, if the measurement accuracy is not to suffer. In the solution according to method claim 2, the distance between the second light barrier and a Münzweiche is at least as large as the diameter of the largest coin to be accepted. In the method claim 1, however, this distance can be chosen smaller because only the immersion of the Coin is considered in the second light barrier and it is not necessary that the coin has completely crossed the second light barrier before a diameter determination is to be made.

A start signal can be generated in the invention of an inductive probe, which is arranged anyway for measurement purposes in the entrance area of the free fall path. However, a start signal can also be generated by the signal of the first light barrier when dipping a coin.

The inventive device according to claim 6 provides in the fall path before spaced light barriers that give signals when dipping and leaving the coins on an evaluation device. The evaluation device calculates the diameter values from the signals which are generated when passing through the coins. In any case, the acceleration of gravity is taken into account in the calculation of the diameter, which makes it possible to determine the diameter of the coins with only two time variables. The invention assumes that the coins fall through the fall path relatively freely after being thrown in, without being slowed down by obstacles. This requirement is normally met by free fall coin validators.

Fig. 1

zeigt schematisch einen Freifallweg eines Münzgeräts mit zwei Lichtschranken.

Fig. 2

zeigt ein Diagramm für die Impulse der Lichtschranken nach Figur 1 beim Erfassen einer diese durchquerenden Münze.

An embodiment of the invention will be explained in more detail with reference to drawings.

Fig. 1

schematically shows a free-fall path of a coin device with two light barriers.

Fig. 2

shows a diagram for the pulses of the light barriers FIG. 1 upon detecting a passing through this coin.

In FIG. 1 is a free fall path 10 indicated for coins. The coins fall in the direction of arrow 12. A first light barrier LS1 has a light transmitter 14 and a light receiver 16. A second light barrier LS2 has a light transmitter 18 and a light receiver 20. The distance between the light barriers LS1 and LS2 is denoted by d. In FIG. 1 Furthermore, a coin 22 is shown above the first light barrier LS1. Furthermore, in FIG. 1 indicated which positions the coin gradually assumes when it passes through the light barriers LS1 and LS2. The coin 22 generates a first signal when it enters the area of the light barrier LS1. This happens at time t1 (see FIG. 2 ). Over a period of time from t1 to t2, coin 22 passes through photocell LS1. Only after leaving the signal falls in FIG. 2 from. This time is, as I said, designated t2. Subsequently, the coin 22 dips into the light barrier LS2, which happens at time t3. Leaving the light barrier LS2 is in FIG. 2 indicated with t4. If the distance d is smaller than the diameter of the coin 22, the time t3 is earlier than the time t2.

$$\mathrm{m}\mathrm{=}\mathrm{d}\left(1-\mathrm{T}\mathrm{3}\mathrm{/}\mathrm{T}\mathrm{4}\right)\mathrm{+}\mathrm{½}{\mathrm{a}}_{\mathrm{0}}\left(\mathrm{T}\mathrm{3}\times \mathrm{T}\mathrm{4}-{\mathrm{T}3}^2\right)$$

The coin 22 has a diameter m. The signals of the light barriers LS1, LS2 and the light receiver 16, 20 go to an evaluation device 24, in which the diameter m is determined. The following formulas serve this purpose: $$\mathrm{m}\mathrm{=}\mathrm{d\; T}\mathrm{2}\mathrm{/}\mathrm{T}\mathrm{3}\mathrm{+}\mathrm{½}{\mathrm{a}}_{\mathrm{0}}\mathrm{T}\mathrm{2}\left(\mathrm{T}\mathrm{2}\mathrm{-}\mathrm{T}\mathrm{3}\right)$$

$$\mathrm{m}\mathrm{=}\mathrm{d}\left(1-\mathrm{T}\mathrm{3}\mathrm{/}\mathrm{T}\mathrm{4}\right)\mathrm{+}\mathrm{½}{\mathrm{a}}_{\mathrm{0}}\left(\mathrm{T}\mathrm{3}\times \mathrm{T}\mathrm{4}-{\mathrm{T}3}^2\right)$$

$$\mathrm{s}\left(\mathrm{t}2\right)\mathrm{=}{\mathrm{v}}_{\mathrm{0}}\mathrm{T}\mathrm{2}\mathrm{+}{\mathrm{a}}_{\mathrm{0}}\mathrm{T}\mathrm{2}\mathrm{=}\mathrm{m}$$

$$\mathrm{s}\left(\mathrm{T}3\right)\mathrm{=}{\mathrm{v}}_{\mathrm{0}}\mathrm{T}\mathrm{3}\mathrm{+}{\mathrm{a}}_{\mathrm{0}}\mathrm{T}{\mathrm{3}}^2\mathrm{=}\mathrm{d}$$

$$\mathrm{s}\left(\mathrm{T}4\right)\mathrm{=}{\mathrm{v}}_{\mathrm{0}}\mathrm{T}\mathrm{4}\mathrm{+}{\mathrm{a}}_{\mathrm{0}}\mathrm{T}{\mathrm{4}}^2\mathrm{=}\mathrm{m}\mathrm{+}\mathrm{d}$$

The quantities used in the formulas are defined by the above description. For the derivation, the following applies to the first formula: $$\mathrm{s}\left(\mathrm{t}\mathrm{1}\right)\mathrm{=}\mathrm{0}$$

$$\mathrm{s}\left(\mathrm{t}2\right)\mathrm{=}{\mathrm{v}}_{\mathrm{0}}\mathrm{T}\mathrm{2}\mathrm{+}{\mathrm{a}}_{\mathrm{0}}\mathrm{T}\mathrm{2}\mathrm{=}\mathrm{m}$$

$$\mathrm{s}\left(\mathrm{T}3\right)\mathrm{=}{\mathrm{v}}_{\mathrm{0}}\mathrm{T}\mathrm{3}\mathrm{+}{\mathrm{a}}_{\mathrm{0}}\mathrm{T}{\mathrm{3}}^2\mathrm{=}\mathrm{d}$$

$$\mathrm{s}\left(\mathrm{T}4\right)\mathrm{=}{\mathrm{v}}_{\mathrm{0}}\mathrm{T}\mathrm{4}\mathrm{+}{\mathrm{a}}_{\mathrm{0}}\mathrm{T}{\mathrm{4}}^2\mathrm{=}\mathrm{m}\mathrm{+}\mathrm{d}$$

The formula for T3 yields: v ₀ = d / T3 - ½ a ₀ T3. This one inserted into the formula for T2 gives the first calculation formula.

$$\mathrm{s}\left(\mathrm{T}5\right)\mathrm{=}{\mathrm{v}}_{\mathrm{0}}\mathrm{T}\mathrm{3}\mathrm{+}{\mathrm{a}}_{\mathrm{0}}\mathrm{T}{\mathrm{3}}^2\mathrm{=}\mathrm{d}\mathrm{-}\mathrm{m}$$

$$\mathrm{s}\left(\mathrm{T}6\right)\mathrm{=}{\mathrm{v}}_{\mathrm{0}}\mathrm{T}\mathrm{4}\mathrm{+}{\mathrm{a}}_{\mathrm{0}}\mathrm{T}{\mathrm{4}}^2\mathrm{=}\mathrm{d}$$

For the second formula applies: $$\mathrm{s}\left(\mathrm{t}\mathrm{2}\right)\mathrm{=}\mathrm{0}$$

$$\mathrm{s}\left(\mathrm{T}5\right)\mathrm{=}{\mathrm{v}}_{\mathrm{0}}\mathrm{T}\mathrm{3}\mathrm{+}{\mathrm{a}}_{\mathrm{0}}\mathrm{T}{\mathrm{3}}^2\mathrm{=}\mathrm{d}\mathrm{-}\mathrm{m}$$

$$\mathrm{s}\left(\mathrm{T}6\right)\mathrm{=}{\mathrm{v}}_{\mathrm{0}}\mathrm{T}\mathrm{4}\mathrm{+}{\mathrm{a}}_{\mathrm{0}}\mathrm{T}{\mathrm{4}}^2\mathrm{=}\mathrm{d}$$

The formula for T6 yields: v ₀ = d / T4 - ½ a ₀ T6. This in conjunction with the formula for T5 gives the second formula for m.

As already mentioned, the light barrier LS1 may be preceded by an inductive sensor for generating a start signal. This sensor is not drawn. However, it is also possible to use the first signal at time t1 of the first light barrier LS1 as a start signal.

Claims (8)

Method for determining the diameter m of different coins traversing light barriers on their free-fall path, characterized in that coins (22) successively only traverse two light barriers LS1, LS2 spaced apart in the direction of fall, the diameter m being of the formula m = d T2 / T3 + ½ a ₀ T2 (T2 - T3) is calculated in the • d the distance of the light barriers LS1, LS2 in the direction of fall T2 the time at which a coin leaves the first light barrier LS 1, • T3 the time at which the coin enters the second light barrier LS2 and • a _{0 is} the gravitational acceleration. Method for determining the diameter m of different coins traversing light barriers on their free-fall path, characterized in that coins are traversed successively only two light barriers spaced apart in the falling direction, the diameter m being of the formula m = d (1-T3 / T4) + ½ a ₀ (T3 x T4 - T3 ² ) is calculated in the D the distance of the light barriers LS1, LS2, T3 the time at which a coin dips in the second light barrier LS2, • T4 the time at which the coin leaves the second light barrier LS2 and • a _{0 is} the gravitational acceleration. A method according to claim 1, characterized in that the distance between the light barriers LS1 and LS2 is smaller than the diameter of the smallest coin to be accepted. Method according to one of Claims 1 to 3, characterized in that a start signal is generated by an inductive probe arranged upstream of the coins (22), Method according to one of claims 1 to 3, characterized in that a start signal is generated by the coins upon entry into the first light barrier LS1. Apparatus for determining the diameter m of different coins which move along a free fall path, with light barriers LS1, LS2 spaced apart in the direction of fall, which, when immersed and leaving the light barriers LS1, LS2, give signals to an evaluation device (24) from which the evaluation device determines the diameter the coins calculated, characterized in that only two light barriers LS1, LS2 are provided, either the signals of the first photocell LS1 when leaving the coins and the signals of the second photocell LS2 when immersing the coins or the signals of the second photocell LS2 and immersing and Leaving the coins in the evaluation device (24) are given to determine the diameter with the aid of the acceleration of gravity a ₀ . Apparatus according to claim 6, characterized in that an inductive sensor for generating the start signal of the first light barrier LS1 is arranged upstream. Apparatus according to claim 6, characterized in that the signal of the first light barrier LS1 is given when dipping the coins as a start signal in the evaluation device (24).

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