CA2140489C

CA2140489C - Method and apparatus for frozen dessert dispensing

Info

Publication number: CA2140489C
Application number: CA002140489A
Authority: CA
Inventors: Helmut A. Alpers; Jon P. Russett
Original assignee: Specialty Equipment Companies Inc
Current assignee: Carrier Corp
Priority date: 1994-05-27
Filing date: 1995-01-18
Publication date: 1999-05-11
Anticipated expiration: 2015-01-18
Also published as: AU2034495A; CA2140489A1; AU698717B2; US5816455A; NZ272005A; US5464120A; JPH0872993A; JP3696653B2

Abstract

A frozen dessert dispensing apparatus is provided with a metering chamber having a predetermined volume into which a frozen dessert product is issued at a uniform constant rate from a bulk source. The time period required to fill the chamber volume determines a characteristic viscosity valve of the dessert product which is advantageously used to time the flow of additional frozen dessert product from the source into and through the chamber to a selected point. The total time required to dispense a desired volume is based upon the viscosity measurement. A reciprocating piston arrangement provides gating of the frozen dessert product from the bulk source when in a first position and further acts to extrude frozen dessert product from the metering chamber when set in motion under the command of a controller. The piston arrangement includes a compressible plunger portion which deforms as necessary to prevent accidents or other mishaps from occurring in pinch-off regions of the apparatus.

Description

21~048Q
~., MBTHOD AIID APPARATU8 FOR FROZ~I D~8~1BRT DI8PEN8IN~
Ba¢k~lGul~d of ~h~ ~nvention This application pertains to the art of dispensing frozen ~es~ert products and, more particularly, to methods and apparatus for v~nAing frozen dessert products in consumer selectable quantities.
The invention i5 particularly applicable to lo vending apparatus for unmanned sale of re~reshments to consumers in malls, places o~ business, public places or the like and will be described with particular reference thereto although it will be appreciated that the invention has broader applications such as chemical mixing operations such as blen~ predetermined portions of different paint colors or any other proce~llres which require automatic fluid dispensing in user-settable quantities .
Frozen dessert dispensing apparatus have heretofore reguired a full time on-site operator or sales person to manipulate the apparatus in order to dispense various quantities of the ~es~ert into a separate carton or edible cone. ThiS human resource burden is largely due to the primitive valving mech~n~sms typically employed in soft ice cream and yGy~l~ dispensers. Those valves are in reality a simple gate mech~nlsm operable in a first position to block the flow of the frozen dessert product from a bulk supply and in a second position to 2140~8~
.
"
permit said flow through a conduit and toward a dispensing head. As illustrated in U.S. Pat. Nos.
4,711,376 and 3,698,206, handles are typically connected directly to the grating mechanisms to provide a rather uncomplicated primitive dessert dispensing apparatus.
Devices of the type described above have become popular over the years but present two (2) major problems from a business perspective. First, an amount of human error is involved in determining the actual serving size.
Although various plastic and waxed containers used in connection with frozen dessert products of this type generally define a serving size, the actual precise amount of product served may vary. Oftentimes, product waste is involved or customers are over-served in the aggregate resulting in a business loss. Further, the costs associated with an on-site employee may be prohibitive. In certain settings, it is conceivable that insufficient demand exists for the soft frozen dessert products to warrant the expenditure of an operator's salary. In areas where sufficient demand exists, such as where a wide variety of products are sold at a common vending area such as a food court for example, the operator's time may be better served tending to the customer's other needs rather than portioning frozen dessert products manually.
One solution is an automatic vending apparatus.

2140~89 w These have been used in the past wherein a plurality of pre-packaged frozen dessert products such as ice cream bars or ice cream sandwiches are sold directly to consumers. One downside of thi~ approach is that the consumers are ~ nted only with predetermined quantity choices.
U.S. Pat. No. 2,559,840 describes an ice cream dispensing device which is capable of issuing various selectable quantities of the frozen dessert product from a bulk storage container. How_ve~, the apparatus described in that patent is somewhat limited in that only multiples of a predetermined minimum guantity may be served. This is due to the ~act that a ~ixed measuring chamber is repeatedly completely filled then completely emptied into a cup or the like to portion out ice cream from the bulk supply. Desired portions which are not multiples of the complete chamber volume are not serviceable.
Another apparatus for dispensing measured quantities of a frozen dessert product is described in U.K. Pat. Appln. 2,230,057. There, a complicated m~c~n1sm including a ram, valve and cyl~nAPr cooperate with a duct to divide a bulk supply of ~rozen ~ecsert product into predetermined portions. One drawback with this system is its complicated nature and resultant disassembly and cleaning di~ficulties. In addition, 21qO4~

spoilage may result because a considerable amount of product residue remains in the ram, cylinder and duct meçh~n~sm bet-ween USQS.
Accordingly, it is clear that a need exist~ for a frozen dessert dispensing apparatus which is easy to USQ, 8implQ to clean and maintain and which i8 capable of dispensing selectable quantities of the dessert product from a bulk source. The ~l--ent invention contemplates new and im~G~ed methods and apparatus for frozen dessert dispensing which overcomes all of the above-referred problems and other~ and provides an apparatus and co..~Lol method for use therewith which i8 simple, economical and profitable.

Brief 8ummary of the ~nvention In accordance with the present invention there is provided a fre~-st~n~n~ self-cont~e~ soft frozen dessert dispensing apparatus c~pAhle of dividing bulk dessert into infinitely variable user-definable quantities over a continuous range.
In accordance with a more limited aspect of the invention, the frozen dessert dispensing apparatus includes a refrigerated main enclosure adapted to receive bulk frozen dessert product refill cartridges onto a dispensing head. The dispen~ing head is easily manually removable from the apparatus for easy cle~n~ng. A piston '~ 2140~8~
~.~

within the enclosure engages the product cartridge on a first open end to apply a slight constant pressure thereto. The ~ cQnA end of the cartridge is adapted to be positioned on the dispensing head substantially within the refrigerated enclosure.
According to a still further aspect of the invention, the dispQnsing head includes an outlet nozzle, a cavity or product queue having a predetermined volume and a reciprocal plunger me~n~sm operable in the chamber. In a first position, the plunger permits frozen product to flow from the refill product cartridge and into the measuring chamber through an op~n~ng therebetween. The second position of the plunger substantially blocks the opPn~ng preventing ~urther product flow from the bulk source.
In accordance with a still further aspect of the invention, plunger travel beyol.d that which blocks the flow of frozen ~e~Drt product from the bulk source induces an extrusion of the ~Pa~.rt product from the measuring chamber through the ~~pencing open~ng thus substantially completely evacuating the chamber of product.
In accordance with yet a further aspect of the invention, a method of frozen ~e~~~rt product dispensing includes timing the interval required to ~ill the measuring chamber, permitting the frozen dessert product to flow from the bulk source and through the measuring chamber for a second timeperiod and lastly completely purging the measuring chamber of the dessert product after the second predetermined time period in order to dispense a user-settable product quantity.
A principle aim of the invention is to dispense user-definable quantities of a frozen dessert product to achieve portion control in an apparatus which is uncomplicated, easy to clean and m~int~in, and operates inexpensively.
Another aim of the present invention is to provide a method of operating a soft frozen dessert dispensing apparatus which facilitates easy control thereover.
The method includes sensing that the measuring chamber is completely full, determining a second time period for continued flow of frozen dessert product through the chamber from a bulk source and operating a plunger to substantially completely purge the measuring chamber. The step of d~ g the time period required to fill the chamber can be elimin~t~d when the chamber defines the desired quantity of dessert.
Accordingly, it is an object of one aspect of the invention to provide a method of dispensing a material in a preselected volume greater than a predetermined ."ini",u". volume from a source of the material to a selected point comprising:
providing a chamber having a predetermined volume no greater than said minimllm volume;
flowing material at a substantially constant first rate from the source of the material to the said chamber and determining the time period required to fill the chamber;
flowing material from the source into and through the chamber to the selected point for a total time that is a multiple of the determined time period, said multiple being substantially equal to one less than the ratio of the preselectedvolume to the chamber volume; and, termin~ting the flow and discharging the entire volume of the chamber to the selected point at the end of the said total time.

It is an object of a further aspect of the invention to provide an apparatus fordispensing a material in a preselected volume no less than a predetermined minimllm volume comprising:
a source of material, said source having an outlet and discharge means for 5 discharging the material from the source through the outlet at a generally constant rate:
a chamber connPcted to the outlet, said chamber having a volume at least as great as said predetermined minimum volume;
timing means for determining the time period required for material 10 discharging from the source through the outlet to fill the chamber to the predetermined ~ volume; and control means operaLively conn~cttod with the timing means for termin~ting flow of material through the outlet to the chamber when the total time of discharge of material from the source to the chamber is a multiple of the time period required 15 to fi11 the chamber to the predetermined minimllm volume, the multiple being equal to the multiple which the preselected volume represents to the predetermined ",ini"~llm volume.
An object of yet another aspect of the invention is to provide a method of fluid portioning for use with a fluid dispensing apparatus including a supply of fluid 20 in a fluid supply chamber connPcted by a valve to a fluid queuing chamber having a fluid discharge opening, the method comprising the steps of:
determining a volume V of a fluid to issue from the apparatus;
filling the fluid queuing chamber evenly over a first time period T by flowing a volume v of said fluid from said fluid supply chamber to said fluid 25 queuing chamber at a first rate;
over-filling said fluid queuing chamber for a second time period T' by flowing additional volume (V-v) of said fluid from said fluid supply chamber at said first rate to said fluid queuing chamber and out through said fluid discharge opening according to (T/v) * (V-v) =T' and 6a ~ ~ ~k ~ 4 ~ ~
after expiry of said second time period, purging said fluid queuing chamber by flowing a residual volume v through said fluid discharge opening.

Brief Description of the D~ aw;~
The invention may take physical form in certain parts and arrangements of parts, plef~lled embodiments of which will be described in detail in this specification 6b ~ 21~0~8~

and illustrated in the accompanying drawings which form a part hereof and wherein:
Fig. 1 is a perspective view of a frozen dessert dispensing apparatus embodying the present invention;
Fig. 2 is a front elevational view, partially broken away, of the dispensing apparatus illustrated in Fig. 1;
Fig. 3 i8 a view o~ the broken away portion of Fig. 2 in partial cross section;
Fig. 4 i8 a cross-sectional view of the dispensing apparatus taken along line 4-4 of Fig. 3;
Fig. 5 is a cross-sectional view of the dispensing apparatus taken along line 5-5 of Fig. 3;
Fig. 6 is an electrical block diagram illustrating the logic and CO~LO1 elements of the dispensing apparatus;
Figs. 7a-7e illustrate a sequence of operating the apparatus of Figs. 1-5 to dispQngQ frozen desgert portions in variable predetermined guantities; and, Fig. 8 i~ a flow chart setting ~orth a preferred method of dispen~ing variable predetermined quantities from thq apparatus of Fig. 1.

Detailo~ De~¢ription of the Drawin~
Referring now to the drawings wherein the ~ 21~04~
",~

showings are for the purposes of illustrating the preferred embodiments of the invention only and not for the purposes of limiting same, the figures show a frozen dessert dispensing apparatus 10 including a dispensing station 12, a bulk product section 1~ and an interface and control section 16.
With reference first to Figure 1, the frozen dessert dispensing apparatus 10 includes a substantially rectangular refrigerated cabinet 18 which sits atop a reinforced pedestal 20. The refrigerated cabinet 18 includes a front face surface 22 which may be lettered, brightly illustrated or provide about its periphery with suitable channel members for supporting replaceable cardboard or plastic product advertisements, operator instructions or the like. In the preferred embodiment, a plurality of thumb screws are used to secure the panels to the cabinet. At least one of the flat panels illustrated in the figure comprising the cabinet 18 are adapted to provide easy access into the cabinet by authorized personnel for purposes such as to replace depleted frozen dessert stock. In the preferred embodiment, the front panel facing the operator pivots on hinges (not shown) and is optionally equipped with a lock to prohibit unauthorized access. An edge of the front panel closes normally open magnetic safety interlock switch (not shown) when the panel is pivoted into a closed 2 1~ 0~8g position sealing the cabinet 18. All power is removed from the device when the door is opened.
The pedestal 20 of the dispensing station 12 includes a substantially square bottom portion defining a solid base 24. The apparatus 10 is thereby suitable for placement onto a support table or countertop in a store or the like. A work surface 26 is defined by the general "L" shape of the pedestal 20 and may include a drip tray (not shown) such as is typical in the dispensing apparatus art.
The various hardware necessary to accomplish the refrigeration of the cabinet 18 including a compressor, condenser and condenser fan are all housed within the pedestal 20. Since these components are heavy, their location within the pedestal adds to the overall stability of the apparatus 10. To provide ventilation thereof, a plurality of vent openings 28 are suitably arranged on the face of the pedestal 20 while a second set of vent openings 30 are arranged on first and second (not shown) sides of the base as well. One or more groups of these vent openings may be combined to cooperate providing flow through ventilation for the air-conditioning hardware housed within the base 24. Vents may also be added to the rear panel of the pedestal (not shown). since it is undesirable that heat may migrate upward from the base 2~ towards the refrigerated cabinet 18, proper heat management, such as through use of fans and vents, is critical.

21~0~8~
.~
..

With continued reference to Figure 1, the dispensing station 12 includes a product discharge 40 disposed on an interface surface ~2 between the refrigerated cabinet 18 and the pedestal 20. This surface is set at an angle to the front face surface as illustrated in order to provide easy operator access to the product discharge 40. The interface surface 42 cooperates with the work surface 26 to provide a handy area within which to position and fill a product container such as a cup, edible cone or dish. During a product dispensing operating mode of the apparatus, the frozen dessert product exits the refrigerated cabinet 18 through an opening 44 provided in an outlet nozzle 46. A
plurality of teeth or serrations ~8 are arranged about the periphery of the generally circular opening 4~. This is best illustrated in Figures 3 and 4. A suitable escutcheon 50 is provided primarily for aesthetics although some insulation and support for the outlet nozzle 46 is thereby provided. The escutcheon 50 also provides support for an infrared transmitter and receiver pair for sensing the dessert product flowing out from the - opening 44. In the preferred embodiment, the infrared sensor pair are completely encased by the escutcheon 50 in order to protect the sensor pair from contamination due to contact with the dessert product. The escutcheon 50 is made of a plastic material having suitable infrared ~ 2140A89 . . .

transmissive properties to enable the sensor pair to cooperatively sense, through the plastic, dessert product ~lowing between the pair.
A pair of illuminated push buttons 58 are disposed on the pedestal and electrically connected to controller apparatus housed within the interface and control section 16. The left push button as viewed in the Figure sQlects a "regular~ ~ize or portion of ~es~ert product while the right push button i~ used to ~elect a "large" portion In addition to the front face surface 22 and the product ~chArge area ~0, the frozen ~eC~ert dispensing apparatus 10 includes an operator command region 52 including a c~ ol panel S4 and a keyed Acce~
closure 5C. In the preferred emho~ent, the control panel 54 is hinged to the interface and co.~ol section 16 using suitable hinges and tech~ques well known in the art. A pair of push buttons 53 are disposed on the control panel and electrically connected to the control apparatus housed within the interface and cG.-~ol section 16 as will be discussed in greater detail below. The push buttons 53 offer cycle initiation options to an operator for changing spent product refill contAiners with full contA~ners. The left push button of the pair 53 initiates a NANUAL RETRACT operation which retracts a piston used to pressurize the refill cartridge. The .

21~gQ
~"...
. ~ , right push button of the pair 53 initiates a TUBE READY
operation. This operation first drives the piston into the full refill cartridge, then pressurizes the cartridge to a slight standby operating pressure. The pressure is increased when the ~es~ert i~ being di~pensed.
Three indicator lighta and a numeric display 55 are also disposed on the greater command region 52 of the interface and CGn~LO1 section 16. From the left as viewed in the Figure, the lights 57 indicate a DEFROST
cycle, a SOLD OUT condition and a LOAD ~lU~E condition respectively. The numeric display S5 is a two (2) digit segmented display for ~27enting the temperature within the refrigerated cabinet 18 derived from a thermocouple signal to an operator. The display 5S also functions to alert the operator in the event of a plurality of failures or error conditions ~S~llcce~ in greater detail below. The indicator light~ 57 are illuminated to provide convenient visual indicia of the operating cycle or mode of the dispensing apparatus.
The refrigerated cabinet 18 includes a cooled region 60 as best understood with reference to Figures 2 and 3. The walls C2 of the refrigerated cabinet 18 are suitably provided with adequate inCul~tion to discourage migration o~ heat into the bulk product ~ection 9~.
A horizontal support member 6~ provides a rigid mount for a rigid dispensing head member 70 shown in 21~0~
, .,~.

Figures 2-5 but best illustrated in Figure 4. The horizontal ~u~o~ member 6~ and manually removable dispensing head 70 ~orm the bottom portion of a frame structure 72 adapted to receive frozen ~ecssrt product refill cartridges 74 thereon.
The dispensing head 70 includes shoulder portions 71 shaped to mate with or otherwise engage a pair of slidable lock members 76 as best shown in Figure S. The lock members are adapted to slide vertlcally on a corresponding pair of guide members 78 (Figure 3).
Although only two (2) guide members and ~o~ rs are illustrated in the prererred arrangement, obviously three (3) or more of each may be used to accomplish the same result which will be described below. In the position illustrated, the lock members hold the dispensing head in place.
The top of the frame structure 72 includes a horizontal cap member 80 adapted to slidingly engage the guide members 78 for vertical movement of the cap movement thereover. The vertical guide members 78 are slightly enlarged at their top portions to define ~riction grip portions 79 which engage and fictionally hold the cap member 80 at the top of the cooled region 60 to facilitate removal of the head member 70. A pair of substantially circular grooves 82, 8~ defined in the cap member 80 and dispensing head 70 respectively, cooperate 2140~9 .... .
" . , to receive and xuy~oL~ a substantially cylindrical rigid sleeve or pocket member 86 therebetween.
The pocket member 86 i8 of sufficient diameter to closely receive a bulk des~ert refill cartridge 90 therein. The refill cartridge 90 may be a waxed cardboard or plastic cylin~r contAin~ng a fresh supply of a frozen dessert product 94 therein. In the preferred embodiment, the refill cartridge 90 holds about 1.5 gallons of frozen ycy~L. A fluid tight interface between the cartridge 9o and the dispensing head 70 is maintained by a plastic end cap 88 attached to the pocket member 86. The end cap 88 has an opQn~ng for the flow of product into the head. This is best illustrated in Figures 3 and 4.
With cont~ e~ but particular reference to Figure 3, the cap member 80 slidably engages not only the guide members 78 but also a reciprocating plunger assembly lOo. More particularly, an op~ning is defined in the cap member 80, the op~in~ being large enough to permit the free travel of a lead screw 102 of the plunger assembly ~00 to rotate and slide therein. The lead screw - 102 is connected to a piston head 10~ through a bearing block 106. The bearing block lOC permits free rotation of the lead screw 102 without inducing a correspon~ing rotation at the piston head 104. The piston head 104 is formed of a semi-rigid com~Gund such as a hard rubber so 2 1 4 0 ~ 8 , .~

as to engage the inner walls 92 of the refill cartridge 90. As the piston 10~ engage~ the inner wall 92 and is forced downward as viewed in FigurQ 3, the frozen dessert product 9~ within the refill 90 i8 urged from the container through an ope~ng 9C provided in the dispensing head 70. Alternately, th~ refill cartridgQ 90 may be formed with an integral piston adapted to slidably engage the walls of the cartridge as well as moving piston 104. Other combination~ well known in the art are also possible.
The upper ends of thQ guide members 78 are fixed to and held spaced apart by a ~ ~..d horizontal frame member C6 which also provides ~u~G~ ~ for a pillow block 108 comprising part of the plunger assembly 100.
The pillow block engages the lead screw at a threaded interface 110 and i~ held in a spatially fixed location by the second framQ member 66. Accordingly, as the lead screw 102 is rotated by an elQctric torque motor (not shown), thQ lead scrQw and pi~ton 10~ attached thereto is advanced downwardly as illustrated in Figure 3. The frozen dessert product 9~ is thereby compressed within the refill cassette go constrained to eY~An~ only as far as permitted by thQ rigid t~lh~lAr pocket member 86. The electric torque motor (not shown) driving the lead screw 102 is operated in the preferred embodiment only when there is a need to dispense thQ product. The frozen _n~

dessert product 9~ is maintained within the frozen dessert dispensing apparatus 10 under normal atmospheric pressure until a constant and predefined pressure for ready dispensing thereof i8 neces~ry. In the preferred emhoA~ment ~cll~c~ below, the product is pressurized two (2) secondc after a draw valve is commanded to retract. Further, a look up table i~ used to tailor the pressure on the product h~e~ on the quantity of product remaining in the cylinder.
lo The details of the frozen ~e~çrt dispensing head 70 will next be ~ ~6~ with particular reference to Figures 3-5. As indicated above, the t~lb~ r pocket member 86 along with a ~ol~e_"o~ ng end cap 88 is received into an ~nnlll~r yLOO~ 84 of the dispensing head ~0 providing a fluid tight coupling therebetween. A
centralized open~ng 96 in the head permits the free flow of frozen dessert product 94 from th~ refill cartridge 90 when the draw valve 120 is in the fully retracted position. The dispensing head 70 includes a dish contour 98 formed between the op~n1~g 96 and the annular y.oove 84 to encourage th~ flow of frozen ~e~ert product 9 toward the centralized opening 96. A plurality of reinforcement ribs 66 extend radially from the opening 96 to increase the rigidity of thQ dispQnsing head in the dish portion 98. An interstitial void or airspace 68 is created by the separation between the reinforcement ribs . 2140~g~

66 and the structure supporting the draw valve 120. This void or airspace i~ advantageously used in the frozen dessert dispensing apparatus 10 to provide additional insulation to the frozen dessert product 9~ within the refill cartridge 90. The dispensing head may be formed of a unitary solid construction. Finger grip detents 77 are disposed in the head to ~acilitate easy manual removal thereof for cle~n~ng or the like.
As best illustrated in Figure 4, the draw valve lo 120 is slidably received within an elongate cylinder 122 exten~nq from a first open end ~2~ to a second end comprising the outlet nozzle ~6. When in a fully retracted position, as schematically Le~e-ented in Figure 7b, the draw valve U~ VCl~ the opDn1ng 96 permitting the frozen dessert product 9~ to freely flow therethrough and into a metering cavity 130 defined by the portion o~ the cylinder 122 forward of the plunger end 126 of the draw valve 120. The metering cavity acts as a type of product queue in a manner to be described in greater detail below. At the other extreme end o~
travel, that is in the fully exten~e~ position, the plunger end 126 of the draw valve 120 engages the inner surface of the outlet nozzle 46. This is schematically represented in Figure 7e. Motion of the draw valve 120 in the forward direction or to the left as viewed in Figure 4 from the fully retracted position extrudes 21g~

measured amounts of frozen dessert product from the metering cavity 130 and through the open~ng 4~ in the outlet nozzl~ ~6. ThQ serration~ ~8 ~uLlolln~ng the op~n;ng ~ give the extruded frozen product a fanciful design appearance. A plurality of circumferential 0-rings 132 are seated in yLoo~e~ and provide a fluid-tight seal between the draw valve 120 and the cyl1n~er 122.
Since it is possible that an operator may inadvertently insert a body pa~t, such as a finger, into the serrated op~ln~ ~ during forward motion of the draw valve 120, a compression spring 1~0 having a predetermined spring constant communicates the forward motivating force from a prime mover 160 to the draw valve 120. The spring constant is selected so as to preclude a pinching off of the body part which may come to be squeezed between the plunger 126 and outlet nozzle ~6.
With continued reference to Figure 4, the compression spring 1~0 is held slightly compressed between a spring pocket 1~2 formed in the draw valve 120 and a forward face 1~4 of a draw valve shoulder 146 formed on a draw valve plunger 138. A rearward face 1~8 of the draw valve shoulder 1~6 engages a draw valve cap 150 which thre~e~ly engagQs internal threads 152 formed in the draw valve 120. The draw valve cap 150 has a central opening therethrough of sufficient diameter to accommodate an elongate connecting portion 154 of the '~ 2 1 ~ 8 9 . ..

draw valve plunger 138. Similarly, the draw valve shoulder 1~6 has an outer diameter sufficiently sized to loosely fit within the draw valve 120 so as to axially slide therein against the force of the compression spring 1~0. A spring guide member 156 engages the compression spring 1~0 to maintain the spring centered within the draw valve 120 and in sguare contact with the forward face 1~4 of the draw valve s~o~ er 1~6.
The co~n~cting portion of the draw valve mates with a prime mover at a connection coupling 200. When the head 70 is manually placed on the frame member 64, a circumferential groove 202 on the co~nection portion 154 engages a fork con~ector 204. The fork connector moves with the prime mover in a manner ~i~cllc~~~ below.
Lastly, with respect to the dispensing head 70 of Figure 4, an infrared transmitter and receiver sensor 162, 163 is provided on the escutcheon 50 near the op~n1ng ~ for sensing the pr~snr~ of frozen dessert product flowing through the open1n~. An indication of the presence of product at the 3e~cor in the position illustrated indicates that the metering cavity 130 is completely full of ~e~sert product. The sensor pair 162, 163 is co~nected to the. prime mover 160 on an electrical signal wire lC~ in order to communicate power and logical signals therebetween.
Figure 6 illustrates a first preferred embodiment the prime mover and dispensing head assembly schematically. In general, the prime mover ~C0 comprises an elc L~..ic co..~ oller 166 which includes a mi~o~oc~ or, memory, and burrerlng in order to perrorm the vArious logical and motiv~tional t~ks described in greater detail below. Electronic cG..L.ollers are readily available, fully con~igured to ~ vlL a wide range o~
applications, the only cu~tomization n._-QaAry being the generation of ~ o~iat- control software to follow the yro~el~lrc_ ~et forth below. In the preferred emho~ment~
the co..~.oller 1n~ s a univ r~al cG..~roller manufa~ e~ by Taylor and i8 identified by their part number X47s75. The interface board i8 also manufactured by Taylor as part number X47573-12.
The electronic ~ ,oller 166 is connected to the s~~r pair 162, ~63 via a 5~g~-l wire 16~. In addition, the co..LLoller 166 i8 further co~nected to the pu~hbuttons 53 on the cG.~L.ol p~nel 5~ and the illuminated push button~ S8 on th- pedestal 20 via a cGI-Llol panel wire bundle lC8.
A stepper motor 170 is directly connected to a ~t~ppor motor drivo circuit 17~ within the elG~L-6-~ic cor-~.oller 166. A suitable arrangement o~ stepper motor drive wires 171carries the loglcal power ~n~l~ from the drive circuit to the stepper motor. A gear box 180 amplifies the torque generated in the stepper motor in ~,~

21~0~9 ., order to actuate a pillow block 182 which thre~e~ly engages a lead screw 184. The draw valve plunger 138 is connected to the pillow block 182 and moves therewith according to the rotation of the stepper motor under the direction of the controller 166.
A second preferred emhoA~ment o~ the prime mover includes a D.C. motor connected to the lead screw 18~ through a dog clutch responsive to changes in the direction o~ rotation of the lead screw. The comronents of this second preferred emho~ment perform the samQ
basic functions as the components illustrated in Figure 6 and, therefore, no separate Figure will be referred to or presented.
The dog clutch is ~nnUlAr in shape and includes threads on the inner circular surface thereof adapted for engagement with the threads of the leadscrew 18~. The outer circular surface of the dog clutch defines a radially exten~ing key member which is adapted to slidably engage a corresponding keyway groove disposed in the dispensing lead 70. The keyway groove extends longitll~;n~lly generally along the axis of the metering cavity 130 and draw valve travel.
Using the above specified components, the draw valve ~20 is caused to move along the axis of the metering cavity until reaching the extreme ends of travel in either the advance of retract positions. At those ~ 21~04~9 ..~

extremes, the rotation of the D.C. motor no longer causes motion of the valve due to the "snap off" action of the clutch. The lead screw turns freely within the clutch.
Upon reversing rotational direction of the motor, the clutch once again re-engages thu~ converting rotation of the lead screw into linear motion of the draw valve.
A first preferred method of operating the frozen dessert dispensing apparatus according to the present invention will next be ~ sed with reference to Figures 7a-7e and 8 and based upon the apparatus set forth in Figures 1-6 above including the first preferred prime mover device.
Initially, the draw valve 120 is held in the position (step 200) illustrated in Figure 7a. This is referred to as the GATE position because the ~low of frozen dessert product F i8 blocked by virtue of the draw valve covering the oren; ng 9 6. With the valve in the GATE position, the controller 66 reads the volume command from the pushbuttons 58 on the pedestal 20 (step 202).
The inputted command will be referred to as VOLCmd.
Although the preferred emho~ment includes a pair of pushbuttons 58 to set a com~mand volume, through simple modification, a thumbwheel switch or dial may be used as an input device to command volumes of various sizes from a range of valves.
Next, a retract command is issued from the 21~0ll~9 electronic controller to the stepper motor 170 to withdraw the valve and pressurize the product refill cylinder permitting thQ metering cavity 130 to fill with the frozen dessert product (step 204). The position illustrated in Figure 7b is referred to a~ the RETRACT
position. As soon as the valve re~c~es the RETRACT
position, a timer is started to count from zero (step 206). The counter i8 perm$tted to increment while the electronic sensor pair ~62, 163 i~ continuously monitored by the electronic ~o~ oller 16C in order to detect as quick as possible the presence of the frozen dessert product at the oren~ng ~ ~qtep 208). Figure 7b illustrates the flow G of ~ Qrt product through the opening and toward the ~e~or.
Once the Fqn~or detects the pre~enc~ of ~essert product at the opsn~g, the timer value i8 read (step 210). The time to completely fill the metering cavity ~30 is T~con~-Since the metering cavity is of a predetermined volume, the time reguired to fill that volume with frozen dessert product is used advantageously to indirectly calculate a relative viscosity index of the dessert.
More precisely, the..flow rate through the opening 96 is known given the volume VOL~et~r of the metering cavity 130 and the time T~econ~ n~ce~s~ry to fill that volume.
In the special case that the volume of the metering "~ 21~0~8~
, ......

cavity is selected to match the minimum command volume, or "small" serving size, no flow rate calculation is necessary.
At this point in ths cycle, the valve is maintained in the RETRACT position while the frozen dessert product is permitted to flow H through the metering cavity and opening into a suitably positioned cup or cont~n~r below the outlet nozzle 46. The timer is immediately reset and pe~mitted to once again count up. The time that the draw valve is to be held in the RETRACT position i8 calculated (step 212) according to:

( Vo~ ) * (VOLa"~ - VQr t ) = T~, ~n~

When the time reaches the calculated remaining time T~ n~ng tstep 214), the draw valve 120 is commanded to traverse its entire strok~ (step 216) by the 1~ electronic controller to first pinch off the opening 96 blocking flow I from the bulk supply as shown in Figure 7d to a fully extended position extruding the product in the metering cavity completely as shown in Figure 7e.
In the event that the opening ~4 adversely affects the overall flow rate through the chamber, a delay time period must be added to the calculated remaining valve. The delay time period is empirically 2141~

derived and programmed into the controller 166. Thedelay is based on the physical construction and size of the opening 44 and the resultant flow rate therethrough.
The draw valve 120 "knows" when to stop since the stepper motor 170 undergoes angular displacement responsive to the number of ptl 1 ~e- issued by the drive circuit 174 within the ~o..L~oller ~6C. The electronic controller i8 programmed to issue only the amount of pulses neceCQ~ry to fully stroke the draw valve. Also, the controller is programmed to issue the pulses in the proper logical sequence in order to obtain left and right actuation of the draw valve through the s~epper motor and lead screw combination. After the draw valve has reached its fully extended position, as best shown in Figure 7e, blocking the flow J of bulk frozen dessert product, a RETRACT command is issued from the drive circuit 174 to the stepper motor to withdraw the draw valve (step 218) to the GATE position shown in Figure 7a.
When the ~econ~ preferred prime mover system is implemented to per~orm the above-described method, the D.C. motor is command to rotate for predetermined time periods causing the draw valve to similarly react or extend. The time periods are selected to be long enough to ensure that full travel is realized. As described above, the draw valve is efrectively divorced from the lead screw at the extreme ends of travel through the '~- 21~0~89 action of the dog clutch.

Operational ~esor~ption The extruder ~G~ ol consists of a co.-LLol, an inter~ace, a display board, and a motor power supply.
All of these boards are required to control the refrigeration, dispensing, and retracting systems.

Cabinet Temperature The refrigeration co.lL~ol of the control system maintains cabinet temperature between 5 and 15~F by monitoring the cabinet thermistor. When the cabinet temperature reaches 15~F, the compressor i8 turned on until the cabinet temperature drops to 5~F. A heater is selectively used in combination with the refrigeration compressor to aid in tempering the cabinet should the temperature drop below 5~F. The evaporator fans remain on at all times except when the cabinet door is open or during a defrost cycle. The cabinet temperature is continuously displayed on a two-digit, seven-segment display 55 in an ~h~Qnse of system errors. A failed thermistor, motor current failure, or sensor failure constitutes a system error. The condenser fans are hard-wired to line voltage and remain on at all times. An operator accessible potentiometer (not shown) on the unit determines what temperature range the cabinet will be i 214~48~
,.~

controlled in. If the potentiometer is turned to the far left, cabinet temperature is controlled between 20 and 30~F. I~ the potentiometer is turned completely right, the cabinet temperature is controlled between 0 and 10~F.

~efrost Cycle The unit selectively enters a defrost cycle every 6 hours. The defrost cycles occur at 3:00 a.m., 9:00 a.m., 3:00 p.m., and 9:00 p.m. Once in defrost, the defrost indicator illuminate~ and the unit enters the heating phase of the cycle. In this phase the compressor and evaporator fans turn off and the heater turns on.
When the defrost thermistor reaches 50~F or the heater safety timer expires, the heater i8 turned off and the soak out timer starts. When this timer times out the compressor is turned on again. When the defrost thermistor detects a temperature below 30~F, the evaporator fans are turned on and the defrost cycle is then complete. The de~rost indicator turns off at this point. The compressor remains on until the cabinet thermistor registers a temperature of 5~F, provided the cabinet thermistor has not failed. The control once again starts cycling the compressor, based on the cabinet thermistor reading, to control the temperature between 5 and 15~F. The display registers the temperature of the cabinet based on the defrost thermistor re~n~s. During '~ 21~i3 18~

regular refrigeration, the cabinet temperature displayed i8 that of the cabinet thermistor readings.

Heater Safety Timer A fifteen (15) minute timer begins whenever the heater is turned on and is reset when the heater is turned off. If this timer times out, the heater is turned off immediately to prevent an unsafe condition.
No error codes are displayed and the unit enters the "soak out" phase of the defrost cycle.

Failed Cabinet Thermistor The control has the ability to detect a bad thermistor. If the cabinet thermi tor appears to be opened or shorted, the control cycles the compressor at a fixed rate and flashes an error code "88" on the display 55. In the event Or a failed cabinet thermistor, the operator remains able to dispense the remainder of the product in the tube. When the tube is sold out or if the piston is manually retracted the piston retracts as usual. However, once the piston is fully retracted, the actuator is locked out until the thQrmistor is replaced or repaired and cabinet temperature can be monitored again. This allows the customer to sell product while waiting for service, but prevents the operator from continually using a malfunctioning unit. The unit still 2 ~ 4~8~

goes through defrost cycles as in normal operation.

Failed Defrost Thermistor If the defrost thermi~tor appear~ to be opened or shorted, the unit cont; nll~C refrigerating as usual and an error code "77~ fl~he~ on the di~play SS. The unit ~kips defrost cycles until the thermistor i8 replaced or repaired. As with a failed cabinet thermistor, the operator remains able to dispense the remainder of the product in the tube. When the tube is sold out or if the piston is manually retracted, the actuator is locked out until the problem is solved.

Door Switch When the door of the cabinet is opened all outputs, including the door light are shut off or lS disabled except for the defrost heater. If the unit is going through the heating phase of the defrost cycle and the door is opened, the heater remains on. If the cabinet is refrigerating and the door i8 opened, the compressor and the evaporator fans shut off until the door is closed. As a safety feature, ir the dispensing motor and/or the draw valve are r~lnn;ng when the door is opened, operation is suspended until the cabinet door is closed. If the door is opened during a draw cycle, the portion size will not be within a specification. The '~ 21404~g draw should be terminated when the door is opened and closed.

Actuator Control SERVE, RETRACT and p~T~n are the three modes of actuator operation are described above. The SERYE
mode is used for maintAin1n~ and dispensing servable product. The RETRACT mods i8 used for e~ ing the actuator to the HOME position to permit product tube replacement and does not allow product delivery. The p~no~n mode is used for automatically placing the piston in the appropriate location for product dispensing in the SERVE mode.

Dispensinq Product In the serve mode, when the small (or large) draw switch 58 is pressed, the draw valve slide motor is activated open. After a 2 cs~on~ delay, (called the actuator on delay) the dispensing motor is turned on at dispensing speed to pressurize the product in the refill cartridge. It will remain on until the control has determined that enough product has been dispensed (see "PORTION CONTROL" for further information). Then the draw valve slidQ motor is activated in the closed direction. If during a draw, the full extension switch is hit and the dispensing motor current overloads, the ''"'- ,, 2140fl89 control presumes the product tube is empty and enters the Retract mode. However, i~ the motor current overloads, and the full extension switch is not active, the control assumes there is an overload, f~ACh~ the sold out light, S and enter~ the Retract mode.

Portion Control The portion control cen~Qrs 162, 163 are located inside the spout guide cover 50. When the product passes through the sensor path, a signal is sent lo to the control indicating product has been sent. For a 5 oz. portion, when the sensor "sees" product, the draw is terminated. For any other size portion (large), the universal control runs a calculation, based on the time it takes to sen~e the product, to determine how much longer the draw should continuQ.

Sensor Failure For any size draw, if no product is sensed fifteen (15) seconds after the draw switch is pressed, the draw should automatically be terminated. An error code "55" will fla~h at ~ 3n~ intervals on the display 55. If the cen$or~ 162, 163 detect product two (2) seconds after the draw switch 58 i8 pressed (after actuator on delay), the draw is terminated and the error code "55" is displayed. If there is a sensor failure, ~ 214~4~

serving will still be permitted and there is no actuator lockout when the product tube is sold out or the piston retracts. A sensor failure could occur if the sensor area on the spout i8 dirty. When a s~lccecsful draw is completed, a draw in which the ~ensor detects product within the a~o~iate time frame, the display will once again indicate cabinet temperature.

Retract Mode If the product tube i8 presumed empty, the manual retract switch is pressed, or a system error occurs, the control enters the Retract mode. Once this mode is entered, the control reverses the piston direction at full ~peQd until the piston is fully retracted. At this point the ~Gn~LO1 waits for the door switch to open and close again, and the preload switch to be pressed to indicate that a tube has been replaced.
Once this occurs and there are no system errors present, the Preload mode i8 entered.

Preload Mode This mode is used to extend the dispensing actuator at full speed until it reaches a preset load.
When the preload mode is initiated the load tube light shuts off. The sold out light remains lit during preload. When the preload current is reached, the - 21g~48~

actuator motor is shut off. The motor current is a function of the pressure on the actuator. The control is now in the serve mode, and the actuator is in position to deliver product. This feature permits immediate product dispensing on the first draw off a new tube. If for some reason a tube is removed but another is not put in, the motor continues moving forward at full speed until the full extension switch i5 reached. The Retract mode is then entered. The draw switch i8 inactive in the Preload mode of operation.

Motor Current The control measures the actuator motor current to estimate the pressure on the actuator. When the full extension switch i8 open in the Serve mode, if the current exceeds the specified overload current the control should flash the sold out light and switch modes to the Retract mode. The actuator should reverse down until the full retraction switch i8 closed. To remove the error, replace the product tube with properly tempered product. Note that there should be no nuisance overloads because the control does not rely on a fuse.
If no motor current is measured at any time when the actuator should be operating, the actuator is shut off and an error code "66" is flashed on the seven-segment display.

21404~9 ~ .. ...

Sold Out Liaht In the Serve mode, when the full extension switch on the actuator closes and a current overload occur~, the sold out light illuminates. This light will remain on until retraction, and preload are completed.
If there i8 a motor current overload, the sold out light should flash. The light will flash during retraction and until the preload mode is entered. When the preload mode is entered, the light will stay on solid. In general, any time this light is on or fl~ ng, product can not be dispensed.

Load Tube Light In the Retract mode, this light illuminates when the full retraction switch is closed. This indicates that the piston is fully retracted. The load tube light however should flash if there is a power failure. The light should flash unit it is reset. The light should be reset when the cabinet door is opened and closed, and the tube loaded switch is activated, indicating that the product tube has been changed.

Power U~
When the system powers up, the mode it is in should depend on how long the system has been without power If the power has been out for less than 30 21~0~8~

minutes, the power-up mode should be the same as the mode it was in when power when out. If the power has been out ~or longer than 30 minutes, the unit should power up in the retract mode (thus retracting the piston) and the sold out LED should flash at ~ sec. intervals on the display until a new tube is loaded. Once the full retraction switch is activated, the load tube light will also flash at ~ sec. intervals unit a new tube is loaded.
This condition can be distinguished between a current lo overload situation because both ~old out and load tube lights will be fl~h 1 ~g when fully retracted. In a current overload situation, the sold to light will be flashing but the load tube light will be on continuously when piston is fully retracted.

Clock Set The control is equipped with a real time clock that is factor set and manually adjustable. The time is only displayed when manually setting the clock. In order to set the clock, the manual retract switch must be pressed while the piston is in the fully retracted position. Note that the actuator will be disabled during this function. Once the clock set function begins, the double digit seven segment display will display the hour of time. If it is p.m., the right decimal point will be illuminated. To change the hour, press the small draw 21~04~

switch button and release, the hour will increment each time the draw switch is pressed. Once the desired hour is displayed, press the manual retract switch. The hour is now set and the minutes will be displayed. To adjust the minutes, proceed in the same manner as before. When the desired minutes are displayed press the manual retract switch, the time will be set and the control should then exit the clock set function. When the clock set function is used, if not activity on the switches occurs for 20 seconds, the control should exit the clock set function with no changes made to the real time clock.
This feature will help to prevent accidental misuse of the clock set function.

Proqramming Jum~ers The extruder interface board allows for programming jumpers to adjust preload and overload current values. By placing a shorting tab (the same as used on the slush interface board) on a particular jumper location, the preload and overload current setpoints will be adjusted.
The invention has been described with reference to the preferred embodiment. Obviously, modifications and alterations will occur to others upon the reading and understanding of this specification. It is my intention to include all such modifications and alterations insofar 2 1 4 1~
,. . .
".~, as they come within the scope of the appended claims or the equivalence thereof.

Claims

1. A method of dispensing a material in a preselected volume greater than a predetermined minimum volume from a source of the material to a selected point comprising:
providing a chamber having a predetermined volume no greater than said minimum volume;
flowing material at a substantially constant first rate from the source of the material to the said chamber and determining the time period required to fill the chamber;
flowing material from the source into and through the chamber to the selected point for a total time that is a multiple of the determined time period, said multiple being substantially equal to one less than the ratio of the preselectedvolume to the chamber volume; and, terminating the flow and discharging the entire volume of the chamber to the selected point at the end of the said total time.

2. The method as defined in claim 1 wherein the step of discharging the entire volume of the chamber to the selected point is performed subsequent to terminating flow to said chamber.

3. The method as defined in claim 1 including the steps of providing a valve forcontrolling flow of the material between the source of the material and the chamber;
and actuating the valve to an open position to begin the timed period; and, closing the valve after said total time which is a multiple of the determined time period.

4. The method according to claim 3 wherein the step of discharging the entire volume of the chamber includes actuating the valve in the chamber to displace the material from within the chamber.

5. The method according to claim 1 wherein the step of flowing the material from the source to the chamber includes flowing the material through a first orifice having a size defining said first rate.

6. The method according to claim 1 wherein the step of flowing the material through the chamber includes flowing the material through a second orifice having a size defining a second rate of flow.

7. The method according to claim 6 wherein the step of flowing the material through the second orifice includes flowing the material through the second orifice at the second rate of flow which is substantially equivalent to said first rate.

8. The method according to claim 6 wherein the step of flowing material from the source into and through the chamber includes flowing the material through the chamber to the selected point for a total time that is said multiple of the determined time period, the multiple being equal to one less than the ration of the preselected volume to the chamber plus a delay time based on said second rate of flow.

9. Apparatus for dispensing a material in a preselected volume no less than a predetermined minimum volume comprising:
a source of material, said source having an outlet and discharge means for discharging the material from the source through the outlet at a generally constant rate;
a chamber connected to the outlet, said chamber having a volume at least as great as said predetermined minimum volume;

timing means for determining the time period required for material discharging from the source through the outlet to fill the chamber to the predetermined minimum volume; and control means operatively connected with the timing means for terminating flow of material through the outlet to the chamber when the total time of discharge of material from the source to the chamber is a multiple of the time period required to fill the chamber to the predetermined minimum volume, the multiple being equal to the multiple which the preselected volume represents to the predetermined minimum volume.

10. Apparatus as defined in claim 9 wherein the control means includes adjustingmeans for varying the preselected volume.

11. Apparatus as defined in claim 9 wherein the control means includes valve means for stopping flow of material through the outlet.

12. A method of fluid portioning for use with a fluid dispensing apparatus including a supply of fluid in a fluid supply chamber connected by a valve to a fluid queuing chamber having a fluid discharge opening, the method comprising the steps of:
determining a volume V of a fluid to issue from the apparatus;
filing the fluid queuing chamber evenly over a first time period T by flowing a volume v of said fluid from said fluid supply chamber to said fluid queuing chamber at a first rate;
over-filing said fluid queuing chamber for a second time period T' by flowing additional volume (V-v) of said fluid from said fluid supply chamber at said first rate to said fluid queuing chamber and out through said fluid discharge opening according to (T/v) * (V-v) = T' and after expiry of said second time period, purging said fluid queuing chamber by flowing a residual volume v through said fluid discharge opening.

13. The method of fluid portioning according to claim 12 wherein the determining step includes reading an input from a user as said volume V of a fluid to issue from the apparatus.

14. The method of fluid portioning according to claim 13 wherein the determining step includes storing the input read from the user in a memory in the apparatus.

15. The method of fluid portioning according to claim 12 wherein the filling step includes filing said fluid queuing chamber with said fluid at a constant rate over said first time period T.

16. The method of fluid portioning according to claim 15 wherein the over-filling step includes flowing said additional volume (V-v) of said fluid from said fluid supply chamber at said first constant rate to said fluid queuing chamber and out through said fluid discharge opening.