NZ191357A

NZ191357A - Coin discriminating apparatus

Info

Publication number: NZ191357A
Application number: NZ191357A
Authority: NZ
Inventors: C M Lewis
Original assignee: Pa Management Consult
Priority date: 1978-08-30
Filing date: 1979-08-20
Publication date: 1984-05-31
Also published as: FR2440135A1; AU4113178A; ZA794213B; PT70092A; AU519354B2; FR2440135B1; DE2848163A1; GB1581061A; AU5019579A; AU531397B2

Description

• % ' 191357 PriOi*- ,-*4^9# r;c -r-% £. ew.Jicattcn Filad: <??.?.?? PubfscstiDn Date: . X Patents Form No. 3 CHANGE OF HAKE GF AffUSAUT <jcr>s><al-hr\(^ -Sv^o\e-€s ,...

PATENTS ACT 1933 COMPLETE SPECIFICATION -• Z*f>rm • "WtJ ■p ^ ^ v^w4''s/9 COIN DISCRIMINATING APPARATUS C.

%Vx\«°' Pfl Con*^"Vs k'd' 11 We, PIjEOOEY IIANDEL 4JM3'company A\yAc ^xrV Wovi«.e, , Uon&or\( S^OVX 7 iJ? \ar\d . of Gartonotraooo DfCJiO0 Eiugj Qwi'tujeii.'luuaiiL, hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be. particularly described in and by the following statement:- / □ Company 1 9 J 3 COIN DISCRIMINATING APPARATUS This invention relates to a coin discriminating apparatus for responding to coins of> valid denominations, discriminating against non-valid denomination coins and forgeries, in coin operated apparatus.

Many coin operated apparatus eacist in many different fields (for example dispensing machines, gaming machines, ticket machines). Protection is required against operation in response to dummy coins or forgeries and against operation in response to coins of the wrong denomination, for example lesser-value coins from coun tries other than the country of use. For example, the German 1DM coin needs protection against other coins of similar size and shape, such as the U.K. 5p coin, the Spanish 5PTAS, the Austrian 5sch and others.

As seen from one aspect, this invention pro vides a coin discriminating apparatus, comprising a transmitting coil connected to a signal generator so as to give an abrupt flux change , a receiving coil, the transmitting and receiving coils being disposed on opposite sides of a path for the passage of coins, means for short circuiting the receiving coil but effec tive to remove the short circuit a predetermined time delay after said flux change, and means responsive to the amplitude of a voltage pulse which is produced across the receiving coil in response to removal 191357 of said short circuit.

In our divisional New Zealand Patent Specification No.oL0}3.2Lb there is described and claimed a coin discrimin-^j^^-ating apparatus comprising a path for the passage of coins in a given direction and first and second coin testing means associated with said path, the first coin testing means being arranged to provide an output representing one of a number of categories to which different valid coin denominations belong, and the second coin testing means being adjusted in response to said output to test specifically for the valid coin denomination represented by said output.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: FIGURE 1 is a circuit diagram of a coin discriminating apparatus; and FIGURE 2 is a series of waveform diagrams applicable to the apparatus of Figure 1; Referring to Figures 1 and 2, a coin discriminating apparatus comprises transmitting and receiving coils 1,2 disposed on opposite sides of a path for the passage of coins, a coin 3 under test being shown between the coils. The transmitting coil 1 is connected to a signal generator, such as a current square -wave generator, so as to give repetitive abrupt flux changes. A transistor k or other switching means is connected across the receiving coil 2 and is driven to short circuit the recei-~ ving coil 2 during the time the abrupt flux changes take place but to remove the short circuit a small, predetermined time delay t_ after each flux change.

Figure 2 shows at (a) the square wave Vtx applied to the transmitting coil and at (b) a drive signal applied to the base of transistor 4. Figure 2 fi*rt 13JULS9dz f • - < - 191357 further shovrs at (c) the voltage waveform Vrx appearing across the receiving coil 2 when no coin or other object is disposed between the two coils, and at (d) the voltage waveform Vrx appearing across the receiving coil 2 when a coin is present between the two coils.

The presence of a coin or other object between the two coils affects the waveform Vrx in ^three ways. Firstly, it affects the manner* in which energy from the transmitting coil is coupled into the receiving coil whilst the latter is short circuited; secondly, it affects the manner in which the receiving coil behaves when the short circuit is subsequently removed; and thirdly the receiving coil is affected by energy induced into the coin by the flux changes in the transmitting coil. Changes in the position of the coin, or its physical characteristics, therefore cause changes in the receiving coil waveform Vrx.

Figure 2(d) shows a voltage pulse or spike % which is produced across the receiving coil 2 in response to the removal of the short circuit, and which is caused induced current circulating in the receiving coil immediately prior to removal of the short circuit. The amplitude of this voltage pulse depends upon what object or coin is present between the coils 1,2. Thus, an amplitude responsive means 5 is connected across the receiving coil 2 and is arranged, in the apparatus shown, to provide an output signal in response to a voltage pulse exhibiting a predetermined amplitude V or, preferably, an amplitude lying between upper and lower predetermined limits, indicating the presence of a correct coin.

In the apparatus of Figure 1, a single preset position of the coin is defined for effecting the test measurement by providing a detector, such as a light path detector, which is responsive to the coin reaching a predetermined position along its path to supply an enabling signal to the amplitude responsive means 5- nktSAfFV180' meanS are PrOVided f°r applying a sampling pulse %aveforn. (e) in Figure 2) a predetermined time delay "T -o\ to JUL 1982 1913 after each removal of the short circuit across receiving coil 2 and coinciding with the occurrence of the voltage pulse (d), which sampling'pulse is a further enabling signal for the amplitude responsive means 5« As in the apparatus described in our divisional New Zealand patent specification No.gj.0iaa.if. in connection with Figures 5 and 6 thereof, the amplitude responsive means is enabled only in the simultaneous occurrence of the sampling pulse and a pulse produced by the light detector in response to the coin reaching its set position. 13 JUL 1982 a-

Claims

WHAT WE CLAIM IS; 191357

1. A coin discriminating apparatus, comprising a transmitting coil connected to a signal generator so as to give an abrupt flux change , a receiving coil, the transmitting and receiving coils being disposed on opposite sides of a path for the passage of coins, means for short circuiting the receiving coil but effective to remove the short circuit a predetermined time delay aftersaid flux change, and means responsive to the amplitude of a voltage pulse which is produced across the . SO-vd VluA 0>VX.t\^)G- a.lN^'VK^ receiving coil in response to^removal of said short • » circuit.

2. An apparatus as claimed in claim 1, in which the signal generator is arranged to apply a square wave signal to the transmitting coil. 1 ' 3- .

An'apparatus as claimed in claim 1 or 2, further comprising a detector responsive to a coin reaching a predetermined position along said path, to supply an enabling signal to the amplitude responsive means. h.

An apparatus as claimed in claim 3> in- which said detector comprises a light path detector.

5. An apparatus as claimed in any preceding claim, further comprising means for generating a sample pulse a predetermined time delay after removal of said short circuit, which sample pulse is supplied as an enabling signal to the amplitude responsive means.

6. An apparatus as- claimed in any preceding claim, in which the amplitude responsive means is arranged to provide an output signal in response to a said voltage pulse of magnitude between predetermined upper and lower limits. 13 JUL &J. 191357

7. -A coin discriminating apparatus substantially as herein described with reference to Figures 1 and 2 of the accompanying drawings. BALDWIN, SON & CAREY ATTORNEYS FOR mi APPLICANTS *13jULI982