[0001] This invention relates to coin-freed mechanisms, particularly coin-freed mechanisms
for automatic vending machines or so-called "slot machines".
[0002] Known slot machines have coin testers which test each individual coin inserted into
the machine for properties such as size and weight, the coin tester rejecting counterfeit
or defective coins before they can release the locking mechanism of the slot machine.
Normally, a slot machine can be opened on the insertion of a number of coins of the
same or different denominations, and the invention was devised to provide a coin-freed
mechanism which checks the complete combination of coins inserted. As indicated below,
however, the invention is also applicable to a coin-freed mechanism which is released
by a single coin of a particular denomination.
[0003] Particular problems arise in devising a coin-freed mechanism which checks a combination
of inserted coins. For example, the mechanism should be able to cope with dissimilar
coins inserted into the machine in different orders and most be capable of aligning
the inserted coins accurately for checking purposes. To allow for different diameter
coins to be inserted, sufficient lateral clearance must be provided in the coin inlet
yet the coins must come to rest in predetermined positions in which an overall dimensions
can be checked.
[0004] These requirements are met by the present invention which provides a coin-freed mechanism
having electrical sensing means which are actuated to free the mechanism by relying
on the electrical conductivity of an inserted coin, or a series combination of inserted
coins, of the correct denomination(s); hence the inserted coins are used to make an
electrical circuit which causes the mechanism to be freed.
[0005] Preferably, the electrical sensing means have contacts which are so positioned and
arranged that they engage the edge of the inserted coin of the correct denomination
or the edges of the coins at the top and bottom of a stack of coins of the correct
combination arranged with their edgesmsting one on the next. Since electrical contact
is made through the edges of the or each coin, the mechanism will not be released
on the insertion of a coin which is made to simulate a coin of a larger denomination
by the expedient of wrapping the edge of the coin with adhesive tape so that it conforms
in size to the larger denomination coin. Also, in the usual case of the mechanism
requiring a certain combination of coins of the correct denomination to be freed,
the sensing means detect the aggregate distance across the edges of the stack of inserted
coins, so that coins of different denominations may be inserted in any order and still
cause release of the mechanism providing that their total value is the correct one.
[0006] One of the contacts is preferably formed at the base of a coin chute and the other
at a position spaced above the lower base contact at a height which is conveniently
adjustable to enable the coin or combination of coins which causes release of the
mechanism to be varied. The coin chute is preferably inclined slightlv to the vertical,
the lower base contact being inclined both with respect to the coin chute and to the
horizontal so that the first coin inserted is caused to occupy a predetermined position
with its edgeresting on the base contact and against one side of the coin chute. The
upper contacts may be pivotally mounted on or adjacent the coin chute, the inserted
coins engaging and pivotally displacing the upper contact as they pass down the chute,
the upper contact returning to its normal position in which it projects into the coin
chute to make engagement with the edge(s) of the coin(s). The upper contact may project
into the chute at a position offset from the diametral line passing through the uppermost
coin and parallel to the chute.
[0007] In one preferred embodiment to be described hereinafter, the lower base contact is
mounted on a slidable drawer which dispenses products from an automatic vending machine
and which is retained in a retracted locked position by the coin-freed mechanism until
the latter is freed on the insertion of the correct combination of coins. When the
drawer is in its retracted position, the base contact is preferably engaged by a spring
contact which is connected in series within the electrical circuit and which ensures
that the latter cannot be completed to free the mechanism unless the drawer is in
its withdrawn closed position.
[0008] The electrical sensing means preferably comprises a solenoid which, when the electrical
contacts are electrically interconnected through the coin(s), is energised to release
a locking mechanism which may take the form of a bolt engageable in a latch plate
attached to the drawer or other lockable member of the automatic vending machine.
[0009] A coin-freed mechanism according to the invention will now be described, by way of
example, with reference to the accompanying drawings, in which:-
Figure 1 is a rear elevation of the mechanism,
Figures 2 and 3 are fragmentary views on the planesA-A and B-B of Figure 1 respectively,
and
Figures 4 and 5 are views respectively similar to figures 1 and 2 but showing an alternative
preferred embodiment, Fig. 5 being a section on the plane c-c of Fig. 4.
[0010] Referring to Figure 1, the coin-freed mechanism is used to lock a drawer J which
is slidable from the locked position shown to an open position in order to dispense
cigarettes in an automatic vending machine. The directicnof opening movement of the
drawer 1 is into the plane of Figure 1. The drawer 1 is fitted with a latch plate
2 (see also Figure 3) into which projects a movable bolt 3 formed by the armature
of an electrical solenoid 4. One terminal of the solenoid 4 is connected by a lead
5 to a battery (not shown) and the other terminal is connected by a lead 6 to a sprung
wiper contact 7 attached at the lower end of a coin chute 8.
[0011] As can be seen from Figure 2, the wiper contact 7 has a sprung lower end which engages
a strip contact 9 mounted in a groove 10 being inclined to the horizontal as shown
in Figure 1. The mechanism has a back panel 12 of wood on which is mounted the solenoid
4 and a channel-shaped piece of clear plastics 13. The chute 8 is defined between
the piece of plastics13 and the back panel 12.
[0012] The plastics piece 13 of the coin chute 8 has an elongated slot 14 within which is
clamped, at a preselected position along the slot 14, a top contact assembly 15 having
a top contact 16 capable of pivoting about an axis X-X relative to a block 17 clamped
in the slot 14 by a clamping screw 18.
[0013] The top contact 16 is connected by an electrical lead 19 to a contact screw 20 mounted
in an insulating block 22 carrying a depending beryllium copper spring contact 23,
the block 22 being mounted on the back panel 12.
[0014] When coins are inserted into the mechanism they fall down the coin chute 8, displacing
the top contact 16 which pivots about axis X-X with a rocking motion as the coins
pass. The inclination of the coin chute 8, combined with the angle of the lower strip
contact 9 mounted on the drawer 1, ensures that the lowermost coin (shown at 24 in
Figure 1) occupies a predetermined position with its outer peripheral edge in contact
with the lower strip contact 9. The strip contact 9 makes an obtuse angle with the
right-hand side of the coin chute 8, as seen in Figure 1. Subsequently inserted coins
25 form a stack, the edges of the coins being in contact one with the next and with
the right-hand edge of the coin chute 8, as seen in Figure 1. If the combination of
coins inserted is the correct one, the top contact 16, which acts as a sensitive feeler,
will engage the edge region of the uppermost coin at a position offset from the diametral
line through the two coins 25.Assuming that the drawer 1 is in its retracted closed
position shown in Figure 2, electrical continuity is established from the top contact
16, through the stack of inserted coins, through the lower strip contact 9 mounted
on the drawer 1, through the wiper contact 7 and thence to the solenoid 4. Completion
of this electrical circuit energises the solenoid 4 the armature of which moves upwardly
to release the drawer 1. The upper end of the solenoid armature carries a nylon cap
26 which, on its upward movement, engages the beryllium copper spring contact 23 and
urges the latter into electrical contact with the contact screw 20 so as to complete
a circuit to a device which produces a "vend accept" audible signal.
[0015] If electrical continuity is not established through the stack of coins, for example
if a coin has been encircled with tape to make it larger in an attempt to pass it
off as a coin of larger denomination, the bolt 3 will remain engaged with the latch
plate 2 and the drawer 1 will not be openable. The coins are returned by the operator
pushing the drawer 1 in slightly to allow the coins to fall through a coin slot 27
(Figure 2) in the drawer 1. It will be appreciated that if the overall size of the
stack of coins, as measured at the off-centre position of the contact or feeler 16,
is not of the predetermined magnitude determined by the position of the block 17 in
the slot 14, the drawer 1 will also remain locked.
[0016] On release of the drawer 1 and the delivery of the product therein, the coins fall
from the chute 8 behind the end of the drawer 1. On return movement of the drawer,
the bolt 3 rides up an inclined edge of the latch plate (shown in Figure 3) before
engaging therein.
[0017] Referring now to Figures 4 and 5 showing an alternative preferred embodiment, certain
parts similar or functionally equivalent to corresponding parts in the embodiment
of Figures 1 to 3 have been omitted for clarity and will not be described. Other parts
requiring description to understand the embodiment have had their reference number
increased by 100 relative to the embodiment of Figures 2 and 3.
[0018] In this embodiment the drawer 100 has a groove 110 with a step 111. A contact plate
109 is secured in the groove 110 and co-operates with a wiper contact 107 attached
to the lower end region of a coin chute 108 that is inclined to the vertical.
[0019] An elongated slot 114 is formed in the chute 108. In the slot 114 are clamped, at
preselected and variable positions, two top contact assemblies 115 and 115a, capable
of pivoting about parallel axes X-X, X'-X' relative to a block 117 clamped in the
slot 114 by a respective clamping screw 118. They are electrically in series. The
two contact assemblies 115 and 115a are essentially identical, so it will be sufficient
to describe one, 115, only. The assembly has a metal plate flap 130 carrying a pair
of aligned screws 116, 132. The screw 116 is in a lower plane as viewed, and its curved
surface (or at least the bottom portion thereof) is provided with an insulated covering
or coating 134. Its plane end face 136 will remain as bare metal so that only this
end face 136 can make electrical contact with the coins to complete a circuit.
[0020] The other screw 132 carries at its end a knob 138 of insulating material. The bottom
surface of the knob 138 is partly chamfered at 140 so that it tapers to a tip 142
on the side nearer the screw 116. The screw 132 with the tip 142 is slightly longer
than the screw 116.
[0021] The operation of this embodiment is essentially similar to that described previously
and only the differences will be highlighted. The mechanism can be actuated by one
high-value coin (such as the newly announced U.K. £1 coin) or by an equal-value combination
of two or more coins. Moreover, if the high-value coin (again, such as the U.K. £1
coin) is of relatively small diameter, the step 111 in the groove 110 will ensure
that it comes to rest in the desired plane and does not, for instance, roll too far
to the right, as viewed in Figure 4.
[0022] When a coin is inserted into the chute 108 the contact assemblies 115, 115a are pivoted
about the axes X-X, X'-X', as before. The screw 132 with the insulating knob 138 and
chamfered surface 140 will be pushed up by the coins and serves to hold the contact
screw 116 out of contact with the coins, unless the coins are "right".
[0023] Moreover, by use of the coating or covering 134 it is ensured that electrical contact
is made only when a correct coin is directly under the end face 136, thereby preventing
fraud e.g. by jogging the drawer or rocking the whole vending cabinet in an attempt
to make coin edge-to-screw contact.
[0024] The contact assembly 115a has a fine adjustment mechanism for its position. The block
117 is slidably mounted in the slot 114 and carries a bracket 150 formed with a threaded
aperture in which engages one end of a fine adjustment screw 152 extending from a
bracket 154 fixed to the chute 108. The other end of the screw 152 has a head 156
which can be turned by a screwdriver to raise or lower the bracket 150 and so the
assembly 115a
[0025] Purely by way of example the mechanism is designed to dispense on (i) one £1 win,
or (ii) two 50p coins, but a) one 10p or 50p or other current U.K. coin would not
have the right diameter or thickness to disable the insulating knob, or b) one 50p
and one 10p coin are of insufficient length and the screws 116, 132 would be above
them in the chute and engage the back panel 12 or c) one 50p and two 10p coins would
be of sufficient length but the wrong thickness and so the chamfered surface 140 would
hold the surface 136 of screw 116 away from the third coin.
[0026] Clearly the selection of the number of contact assemblies, their distance from each
other, the distance between the screws 116, 132, the angle of chamfer on the knob
138 are all best determined emperically to suit the coinage of a given country.
1. Coin-freed apparatus for a vending machine, comprising an electrical circuit controlling
a part of the apparatus which permits or prevents the apparatus to be freed and goods
to be dispensed from the machine, and coin-sensing means, characterised in that said
coin-sensing means are electrical and form part of said circuit; and that the said
circuit is normally open across said sensing means, the insertion of a predetermined
number and size of coins being effective to establish a conductive path across said
sensing means to close and energize the circuit and to free said part.
2. Apparatus according to claim 1, characterised in that said sensing means are contact
elements positioned and arranged to engage the edges of coin(s) of correct denomination(s)
and diameters.
3. Apparatus according to claim 1 or claim 2, characterised in that the coin-sensing
means are contact elements one of which is formed at the base of a coin chute and
the other at a position spaced above the said one contact element at a height which
is adjustable to enable the coin or combination of coins which causes release of the
mechanism to be varied.
4. Apparatus according to claim 3, characterised in that the coin chute is inclined
slightly to the vertical, the lower (one) contact element being inclined both with
respect to the coin chute and to the horizontal so that the first coin inserted is
caused to occupy a predetermined position with its edge resting on the lower (one)
contact element and against one side of the coin chute; the upper (other) contact
element is pivotally mounted on or adjacent the coin chute, the inserted coins engaging
and pivotally displacing the said other contact element as they pass down the chute,
the said other contact element returning to its normal position in which it projects
into the coin chute to make engagement with the coin(s).
5. Apparatus according to claim 4, characterised in that said other contact element
projects into the chute at a position offset from the diametral line passing through
the uppermost coin and parallel to the chute.
6. Apparatus according to claim 3, characterised in that the lower (one) contact element
is mounted on a slidable drawer which dispenses products from an automatic vending
machine and which is retained in a retracted locked position by the coin-freed mechanism
until the latter is freed on the insertion of the correct combination of coins.
7. Apparatus according to any preceding claim, wherein the electrical sensing means
includes a solenoid which, when the electrical contact element(s) are electrically
interconnected through the coin(s), is energised to release a locking bolt engageable
in a latch plate attached to the drawer or other lockable member of the vending machine.
8. Apparatus according to claim 3, characterised in that said other contact element
is disposed adjacent to and movable with an insulated feeler member, the latter being
effective to gauge the height of coins and to hold the said other contact element
away from undesired coins.
9. Apparatus according to claim 8, wherein there is a plurality of series-connected
other contacts.