Vending machine

A vending machine (10) including a cabinet (12) having therein a storage compartment (21) and product extraction means (20) including a base (29) operatively connected to the cabinet for pivoting about vertical axis (27), first link means (25a) horizontally pivoted to the base, second link means (25b) horizontally pivoted to the other end of the first link, actuator for respectively pivoting the base, first link and second link, and coupling means operatively connected (through guide head (33)) to the other end of the second link means (25b) for coupling with a selected product in the storage compartment (21) for delivery to a product station, the extraction means (20) being controlled by control means (15) after product selection by a customer.

TECHNICAL FIELD OF THE INVENTION
 This invention relates to vending machines.
 The invention has particular application to vending machines for vending
 chilled or frozen products especially in pre-packaged form. However, it
 will be appreciated that the invention may also be used with other
 vendible products.
 BACKGROUND ART
 The presently available vending machines for vending frozen products fall
 into two main types. The first type has a cabinet containing a plurality
 of racks each normally arranged to contain one product line and having a
 pusher or the like for dispensing a product from the rack upon selection
 of the desired product by a customer. In some cases, instead of using a
 pusher each rack may be an auger which rotates to move a product held
 therein into a delivery chute. This general type of machine is illustrated
 in U.S. Pat. No. 5,025,950 to Trouteaud et al. It will be appreciated that
 in this type of machine, the number of products held in each rack is
 fairly small and the product line is limited to a fairly specific size and
 shape to suit the rack. Furthermore, each rack requires an undesirably
 large space in order for the dispensing mechanisms to work effectively and
 the racks themselves must be contained in the freezer compartment which
 therefor must be undesirably large.
 A second known type of vending machine includes a freezer cabinet which
 houses an extraction device arranged to extract a desired product from the
 freezer upon selection by a customer and dispense it via a dispensing
 chute. In such apparatus the extraction device typically includes a beam
 crane or gantry crane movable to any selected x, y co-ordinates within the
 cabinet whereupon a suction device supported by the crane moves down into
 a product compartment at the selected co-ordinates and attaches itself by
 suction to a product and then lifts it clear of the product compartment
 then the crane moves to a position above a dispensing chute and releases
 the selected product which slides down the chute for collection by the
 customer. In this type of machine the beam crane is typically moved by
 motor driven (closed loop) cables or rack and pinion devices. A variation
 on this type of vending machine is disclosed in U.S. Pat. No. 5,240,139
 which describes a machine in which a beam crane is movable to any selected
 x, y co-ordinate above a chest freezer and also includes a mechanism for
 opening the door of the chest freezer so that a selected product can be
 extracted and then allows the door to close after the product has been
 extracted. It will be appreciated that in this machine, the extraction
 mechanism is housed outside the chest freezer and is not subject to the
 hostile environment of the other types mentioned and furthermore, the
 chest freezer can be almost fully allocated to product storage.
 It is an object of the present invention to provide a vending machine which
 has at least some of the advantages proffered by the use of a chest
 freezer in a vending machine and to provide additional advantages arising
 from the use of a different extraction device.
 DISCLOSURE OF THE INVENTION
 With the foregoing in view, this invention in one aspect resides broadly in
 a vending machine including:
 a cabinet;
 a storage compartment in said cabinet for storing products to be vended,
 said storage compartment having an upwardly directed access opening;
 product extraction means in said cabinet for extracting products from said
 storage compartment and a customer accessible product station for
 receiving products extracted by said product extraction means;
 selection means on a customer accessible position of said cabinet for
 selecting a product to be extracted;
 control means in operative communication with said product extraction means
 for controlling the operation of said product extraction means in response
 to a product selection;
 said product extraction means including a base member operatively connected
 to said cabinet or mounted in said cabinet for pivoting movement relative
 thereto about a vertical axis and first elongate link means operatively
 connected at one end to said base member for pivoting movement relative
 thereto about a first horizontal axis and second elongate link means
 operatively connected at one end to the other end of said first elongate
 link means for movement relative to said first elongate link means about a
 second horizontal axis, first actuation means operatively connected to
 said first elongate link means and said base member for pivotally moving
 said first elongate link means about said first horizontal axis, second
 actuation means operatively connected to said first and second elongate
 link means for pivotally moving said second elongate link means relative
 to said first elongate link means above said access opening about said
 second horizontal axis, third actuation means operatively connected to
 said base member for pivotally moving said base member about said vertical
 axis, and coupling means operatively connected to the other end of said
 second elongate link means for coupling with a selected product wherein it
 may be extracted from said storage compartment.
 In another aspect the invention resides broadly in a vending machine
 including:
 a cabinet;
 a refrigerated storage compartment in said cabinet for storing chilled or
 frozen food products, said storage compartment having an upwardly directed
 access opening and a compartment closure for closing said upwardly
 directed access opening;
 product extraction means in said cabinet for extracting chilled or frozen
 food products from said storage compartment and a customer accessible
 product station for receiving products extracted by said product
 extraction means;
 opening means operatively connected to said compartment closure for
 selectively opening said closure to allow said product extraction means
 access to food products in said refrigerated storage compartment;
 selection means on a customer accessible position of said cabinet for
 selecting a product to be extracted;
 control means in operative communication with said product extraction means
 for controlling the operation of said product extraction means and said
 opening means in response to a product selection;
 said product extraction means including a base member operatively connected
 to said cabinet or mounted in said cabinet for pivoting movement relative
 thereto about a vertical axis and first elongate link means operatively
 connected at one end to said base member for pivoting movement relative
 thereto about a first horizontal axis and second elongate link means
 operatively connected at one end to the other end of said first elongate
 link means for movement relative to said first elongate link means about a
 second horizontal axis, first actuation means operatively connected to
 said first elongate link means and said base member for pivotally moving
 said first elongate link means about said first horizontal axis, second
 actuation means operatively connected to said first and second elongate
 link means for pivotally moving said second elongate link means relative
 to said first elongate link means above said access opening about said
 second horizontal axis, third actuation means operatively connected to
 said base member for pivotally moving said base member about said vertical
 axis, and coupling means operatively connected to the other end of said
 second elongate link means for coupling with a selected food product
 wherein it may be extracted from said storage compartment.
 Preferably, said product extraction means is mounted on a stand in said
 cabinet and said third actuation means is operatively connected to said
 stand and said base member so as to move said base member relative to said
 stand.
 Preferably, the vending machine includes fourth actuation means operatively
 connected to said coupling means for moving said coupling means up and
 down with respect to said second link means so that said coupling means
 may couple with products located at any depth within the storage
 compartment. It is also preferred that said coupling means include a
 flexible and resilient coupling head adapted to abut a surface of the
 selected product in such manner that vacuum pressure provided at said
 coupling head may cause the product to be "sucked" on to the coupling head
 thus being securely engaged, the vacuum being provided by a vacuum pump or
 other source of vacuum operatively connected to said coupling head by a
 tubular member such as a vacuum tube or hose connected to said coupling
 head at one end and at the other end to the vacuum pump. Preferably, such
 vacuum pump or other source has a low flow rate and provides a relatively
 high negative pressure vacuum, for example, 6 cubic metres per hour at -80
 kPa. Advantageously, such high negative pressure is believed to decrease
 the possibility of product slippage sideways and resultant dropping of the
 product whilst being extracted. In such form of the invention, the vacuum
 pump is remote from the first and second link means and the tubular member
 is attached in such manner to allow up and down movement of said tubular
 member in conjunction with said coupling means. In a preferred form said
 tubular member is supported by a semi-rigid sheath which connects said
 coupling means to said fourth actuation means and preferably the sheath is
 a helical spring which is guided for linear movement along or beside said
 first and second link means by rollers mounted thereon whilst in another
 embodiment the spring passes through a tubular sleeve. Suitably, the
 spring has sufficient flexibility to allow bending so as to accommodate
 pivoting movement of said first and second link means but is sufficiently
 rigid for linear movement therealong or therebeside. It is also preferred
 that said fourth actuation means be a short stroke linear actuator
 connected to said spring via a crank adapted to cause movement of the
 spring so that the coupling means can be lowered from a first position
 above the storage compartment to a second position on or close top the
 bottom of the storage compartment. For this purpose it is preferred that
 the spring have sufficient flexibility to bend through an arc of about 90
 degrees at a radius of about 500 mm to 800 mm.
 Preferably, said control means is arranged to control said first and second
 actuators for movement in unison so that the height of said distal second
 end relative to said access opening is maintained substantially constant.
 It will be appreciated that in such case the height of the coupling means
 will be varied for coupling with the selected food product. It is also
 preferred that said control means include sensing means for sensing
 contact with or proximity to a product to be extracted or other suitable
 parameter whereby coupling may be effected. In one form of the invention,
 said sensing means is a proximity switch mounted on or adjacent said
 coupling means for sensing the position of the coupling means relative to
 a selected product whereby downward movement of the coupling head can be
 stopped upon said coupling head reaching a position at a predetermined
 distance from the product and vacuum may be applied to said coupling means
 to effect coupling and upward movement may be commenced once coupling has
 been effected or after a predetermined period. In another embodiment, said
 sensing means includes a contact member operatively connected to said
 coupling means and adapted for progressive displacement upon contact with
 the product to be extracted and a micro-switch arranged to sense a
 predetermined amount of displacement of said contact member.
 In yet another aspect the invention resides broadly in a vending machine
 including:
 a cabinet;
 a refrigerated storage compartment in said cabinet for storing chilled or
 frozen food products, said storage compartment having an upwardly directed
 access opening and a compartment closure for closing said upwardly
 directed access opening;
 product extraction means in said cabinet for extracting chilled or frozen
 food products from said storage compartment and a customer accessible
 product station for receiving products extracted by said product
 extraction means;
 opening means operatively connected to said compartment closure for
 selectively opening said closure to allow said product extraction means
 access to food products in said refrigerated storage compartment;
 selection means on a customer accessible position of said cabinet for
 selecting a product to be extracted;
 control means in operative communication with said product extraction means
 for controlling the operation of said product extraction means and said
 opening means in response to a product selection;
 transfer means for receiving extracted food products from said product
 extraction means and transferring said products to said product station,
 said transfer means including a chute and guide means for guiding a
 product to be transferred into said chute, said guide means being movable
 in response to a product selection from a stowed position remote from said
 storage compartment to a guiding position adjacent said storage
 compartment upon opening of said compartment closure;
 said product extraction means including a base member operatively connected
 to said cabinet or mounted in said cabinet for pivoting movement relative
 thereto about a vertical axis and first elongate link means operatively
 connected at one end to said base member for pivoting movement relative
 thereto about a first horizontal axis and second elongate link means
 operatively connected at one end to the other end of said first elongate
 link means for movement relative to said first elongate link means about a
 second horizontal axis, first actuation means operatively connected to
 said first elongate link means and said base member for pivotally moving
 said first elongate link means about said first horizontal axis, second
 actuation means operatively connected to said first and second elongate
 link means for pivotally moving said second elongate link means relative
 to said first elongate link means above said access opening about said
 second horizontal axis, third actuation means operatively connected to
 said base member for pivotally moving said base member about said vertical
 axis, and coupling means operatively connected to the other end of said
 second elongate link means for coupling with a selected food product
 wherein it may be extracted from said storage compartment and delivered to
 said transfer means.

DETAILED DESCRIPTION OF THE DRAWINGS
 The vending machine 10 illustrated in FIG. 1 has an outer cabinet 11 having
 a base wall 11a, a top wall 11b, two spaced apart side walls 11c and 11d,
 a rear wall 11e and a removablefront wall 11f having an outer frame and
 two side by side hingedly mounted doors 12a and 12b which allow access to
 the interior of the cabinet for maintenance and restocking. A product
 selection panel 13 is mounted on the front door of the cabinet in the
 normal manner for operation by a customer for selecting a desired product
 and an electronically operated message display unit 14 is located above
 the selection panel. Similarly a coin mechanism 16 and associated coin
 retrieval chute are mounted in the front door in the usual manner.
 A glass window 17 is also provided in the front door and extends across a
 large part of the upper portion of the cabinet whereby a customer may view
 the extraction and dispensing of the selected product which can be
 collected from the delivery station provided in the lower part of the door
 12a.
 A chest freezer 21 having a food storage compartment 21a stands in the
 outer cabinet for storage of frozen food products, particulary ice creams
 and ice blocks which are typically stacked in plastic or cardboard
 containers opening upwardly towards the lid 22. The lid is pivotally
 mounted at its rear edge by two spaced apart hinge assemblies 22a for
 opening upwardly towards the rear wall of the cabinet 12 so that the food
 products can be accessed from the top of the freezer. Advantageously, the
 hinge assemblies are constructed to allow the lid to open within the plan
 area of the freezer so that the maximum width freezer can be accommodated
 in a preselected size cabinet.
 A product extraction unit 20 for extracting products from the freezer and
 delivering them to the delivery station via delivery chute 19 is mounted
 to a stand 24 in the cabinet 12 which in turn is secured to the base wall
 of the cabinet adjacent one side of the freezer. The product extraction
 unit includes a base 29 and a first parallel linkage arm assembly 25a
 connected at one end to the base and a second parallel linkage arm
 assembly 25b connected to the other end of the first arm assembly. The two
 arm assemblies operate in unison as will be more fully described later. A
 shaft 26 depends from the base 29 and is supported in bearings mounted to
 the stand for pivotal movement about a vertical axis 27 adjacent the side
 wall of the chest freezer, the base being secured to the shaft for
 pivoting movement therewith. The first parallel linkage arm assembly
 includes a first arm member 28 which is pivotally connected at one end to
 the base 29 by a horizontally disposed pivot pin 30a for up and down
 pivoting movement and at the other end to a connector member 31 by a
 horizontally disposed pivot pin 30b. A second arm member 32 is also
 pivotally connected to the connector member by a horizontally disposed
 pivot pin 30c for allowing up and down pivoting movement of the second arm
 member relative to the connector member. At its other end the second arm
 member 32 is pivotally connected to a guide head 33 by a horizontally
 disposed pin 30d, the guide head having a passage 34 for slidably
 receiving a extraction tube 35 therethrough for up and down movement into
 and out of the freezer compartment as will be explained more fully later.
 The orientation of the guide head such that the passage 34 is
 substantially vertical is maintained by first and second link members 36
 and 37 which are pivotally connected to the base, connector member and
 guide head respectively in parallel with the respective first and second
 arm members.
 Movement of the first and second arm members is effected by first and
 second linear actuators 38 and 39 respectively, the first linear actuator
 being pivotally connected to the base 29 and the first arm member whilst
 the second linear actuator is pivotally connected to the first arm member
 and the second arm member in such manner that as the respective linear
 actuators extend in unison the first arm member pivots relative to the
 base 29 and connector member 31 and the second arm member pivots relative
 to the connector member and the guide head so that the two arm members are
 extended to place the guide head 33 at a desired position above the chest
 freezer with the height of the guide head being maintained substantially
 constant.
 Pivoting of the base 29 about the axis 27 is effected by a third actuator
 41 which is pivotally connected at one end to the shaft via a crank
 assembly having a crank arm 43 extending radially from the shaft and an
 intermediate link arm 42 as will be more clearly understood from FIG. 4.
 Movement of the guide head 33 relative to the freezer is controlled by an
 electronic controller 15 mounted on the stand 24 which causes the first,
 second, and third actuators to position the guide head above a particular
 product according to preprogrammed coordinates in response to a product
 selection made by a customer operating selection panel 13 after the
 appropriate payment has been made via coin mechanism 16. The position of
 the guide head is determined by the distance each actuator has extended
 from a predetermined datum and the preset coordinates are selected
 according to a particular extension of each actuator. The amount of
 extension is determined by the inclusion of signal pulse generators
 attached to the respective actuators and one or more pulses are generated
 upon one revolution of the actuator motor depending on the degree of
 accuracy required for positioning of the guide head.
 The extraction tube 35 in this embodiment is a coil spring which is
 operatively connected at one end to an actuator 48 within the stand 24 by
 a crank assembly 45 and passes through a passage 46 provided in the shaft
 26, beside the two arm members 28 and 32 and through the passage 34 in the
 guide head 33 to terminate in a free end 35b which moves up and down into
 and out of the freezer compartment under the action of the actuator 48.
 The path of movement of the spring beside each of the arm members is
 guided by tubular guide members 49 and 51 connected to the first and
 second arm members respectively. The path of movement of the spring within
 the frame assembly below the shaft 26 is guided by a plurality of spaced
 apart guide roller assemblies 52 each having three guide rollers 53 and
 the crank arm 47 is arranged to move through a maximum arc of
 approximately 90 degrees to move the free end of the extraction tube down
 and up from a position above the freezer compartment to a position near
 the bottom of the freezer compartment as required. The operation of the
 extraction tube is more clearly shown in FIG. 11 and an alternative
 arrangement is shown in FIG. 12. In these drawings it can be seen that the
 crank assembly has a shaft which is mounted for pivotable movement about a
 horizontal axis extending across the vending machine from side to side and
 that the actuator 48 is connected at one end to the frame assembly and at
 the other end to a first crank arm 54 extending from the shaft and that
 the other crank arm 47 extends from the other end of the shaft and is much
 longer to give the required arc of movement. The alternative arrangement
 for guiding the extraction tube illustrated in FIG. 13 includes a sleeve
 member 71 suitably curved at the same radius as the arc of movement of the
 extraction tube. The sleeve member has a slot 72 extending from one end of
 the sleeve to the other and adapted to receive therethrough the end
 portion of the crank arm 47 for moving the extraction tube within the
 sleeve. The sleeve is mounted to the stand 24 by brackets 73 only one of
 which is shown.
 A vacuum tube 61 extends fully through the extraction tube 35 and is
 connected at one end to a vacuum pump 62 mounted to the frame assembly and
 at its other end to a bellows type rubber suction cup 63, the mouth of
 which is adapted to deform to the shape of the surface of the article to
 be extracted as vacuum is applied via the vacuum tube. A proximity switch
 64 is attached to the extraction tube near its free end and electrically
 connected to the controller 15 by wire 60 for sensing the position of the
 free end or the suction cup relative to a product to be extracted and the
 controller is configured to switch the vacuum pump on in response to a
 signal from the proximity switch. In an alternative embodiment illustrated
 in FIGS. 6 and 7, a micro-switch is used instead of the proximity switch.
 In this arrangement, an inner sleeve 66 is fitted to the free end of the
 extraction tube and an outer sleeve 67 is slidably mounted on the inner
 sleeve, the outer sleeve forming a shroud about the suction cup 63 and
 being adapted to slide relative to the inner sleeve upon making contact
 with the product 65 to be extracted. A two part switch having a reed 68
 mounted on the inner sleeve and axially spaced from the outer sleeve and a
 complementary magnet 69 mounted on the outer sleeve. Movement of the outer
 sleeve relative to the inner sleeve by a predetermined distance causes the
 reed and the magnet to engage, thus causing the controller to switch the
 vacuum pump on.
 The opening and closing of the lid 22 is effected by a fifth linear
 actuator 56 which is connected at one end to the wall of the freezer and
 at the other end to the lid via a link member 55, the actuator also being
 controlled by the electronic controller.
 The delivery chute 19 has a base wall 19a forming the base of the delivery
 station 18, two spaced apart side walls 19c and 19d, a rear wall 19e
 adjacent the freezer and a front wall panel 19f adjacent the cabinet front
 wall 11f. The chute has a product entry 19g at its upper end for receiving
 products from the extraction unit. It will be appreciated that the overall
 width of the vending machine, front to rear must be limited to allow
 passage through doorways and the like and accordingly the size of the
 chest freezer which can be accommodated in the cabinet is limited and so
 to the width of the delivery chute. The chute in this case includes a door
 or flap 19h at its upper end which opens in response to opening of the
 freezer lid 22 towards the freezer compartment. Advantageously, the door
 acts as a guide for products being dropped into the chute by the product
 extraction unit thus allowing the width of the chute to be minimised and
 the freezer width to be maximised. opening of the door 19h is effected by
 a bowden cable 19j which is connected at one end to the door by a crank
 assembly 19k and to the freezer lid at the other end.
 In use, a customer selects a desired product by pressing a button on the
 control panel 13 whereupon an electronic signal causes actuator 56 to open
 the lid of the freezer so that the desired product can be extracted by the
 product extraction unit. As the lid opens the chute door 19h opens to
 provide a product guide and once the freezer lid is open the product
 extraction unit moves to a position wherein the guide head is directly
 above the compartment containing the desired product (as indicated in
 phantom in FIG. 5) whereupon the actuator 48 causes the spring and the
 vacuum tube sheathed thereby with the attached suction head to move
 downwardly towards the desired product. Upon the suction head reaching a
 position of close proximity to the product, the suction head "sucks on" to
 the product and downward movement of the extraction tube is stopped in
 response to transmission of a signal from the proximity switch 64 and
 subsequently the actuator 48 retracts the extraction tube and the product
 attached to the suction head to a position above the freezer. Once the
 product is above the freezer as indicated by the position of the actuator
 48 (by a signal pulse transmitted to the controller) the product
 extraction unit pivots about axis 27 and moves to a position above the
 chute 19 where it releases the product thereinto. The product extraction
 unit then moves to the fully retracted disposition illustrated in FIG. 5
 and the lid is closed by actuator 56 ready for the next customer. In order
 to inhibit accidental early release of a product from the suction cup due
 to twitching of the proximity switch, the vacuum tube is connected to the
 vacuum pump via a valve assembly 81. The valve assembly includes a vacuum
 activated switch 82 which closes upon start-up of the vacuum pump to
 complete an auxiliary power supply circuit to the pump, and a vacuum
 release valve 83 adapted to release the vacuum from the vacuum tube 61
 upon the product extraction unit reaching a predetermined delivery
 position so that the product can be released.
 It will of course be realised that while the foregoing description has been
 given by way of illustrative example of the invention all such and other
 modifications and variations thereto as would be apparent to persons
 skilled in the art are deemed to fall within the broad scope and ambit of
 this invention as defined in the appended claims.