GB2173089A - Ice-cream making and food processing machine - Google Patents

Abstract

A domestic food processing machine has a processing vessel 60, a drive motor 10 outside of the vessel, a rotatable drive ring 38 surrounding the entrance to the vessel and in driving connection with the motor so that the ring is rotated at low speed and with high torque, and processing tools (e.g. 62 Figs. 5A, 5B) interchangeably engageable with the drive ring to process foodstuffs in or entering the vessel.The apparatus includes means (6 Fig. 1) to refrigerate the vessel so that it can be used for ice-cream making, and the drive ring is supported in an assembly 14 housed in a recess 16 of the machine body 12 and disengageable from the motor and vessel. <IMAGE>

Description

SPECIFICATION Improved ice-cream making and food processing machine This invention relates to domestic food processing appliances, and more particularly to an apparatus which, whilst primarily intended for the making of ice-cream and other dairy products, can also form the basis of an extended food processing system.

A wide range of power operated domestic appliances is availablefor processing foods in various ways ranging from mixers and blendersforfluid materials, whether liquid or particulate, to apparatus for chopping, slicing, grinding, liqidizing, juicing or blending initially solid foodstuffs. In many cases, interchangeable parts are available so as to provide systems carrying out many different functions. These devices tend to fall into three general categories. First, there are hand held devices such as hand mixers and blenders, which typically have a hand held body containing an electric motor, and tools or a tool carrying head which project from the body for insertion into a container holding material to be processed by the device.In orderto avoid problems due to the transmission oftorque from the deviceto the containers, the tools are either operated at very high speed with low torque, orcontrarotating tools are provided in a symmetrical arrangement.

Secondly and thirdly, there are two general categories oftabletop device, in which the drive motor and theprocessingzoneareintegratedintoafreestanding unit, although the container if used is usually removable. In the second category, operating tools depend into a container from an overhead drive, which usually requiresto be movable orhinged to allow removal of the container and interchange oftools. This arrangement is most useful for mixers operating on fluid and particulate materials.In the third category, originally including table blenders and more recently food processors capable of a wider range oftasks, a bottom drive is provided beneath a processing zone, with a central shaftwhich drives tools located in a container or a vessel defining a passage through which food being processed can move continuously. This arrangement is most useful for blending and comminuting operations of various kinds. It has the disadvantagethatthe drive must pass through the bottom of any container, thus making the container of an awkward comfiguration and/or difficultto empty, and requiring effective sealing of the drive shaftto prevent entry offoreign matter into the shaft bearings or drive.

Home ice-cream making machines have been proposed having both top and bottom drives. Both types of drive are difficult to implement satisfactorily because ofthe low speed and high torque required to propel the mixing elements th rough the ice-cream mix as it freezes.

I have now devised a new form of drive which, whilst originally devised for ice-cream making machines, isalso applicableto awhole rangeofother food processing appliances, and when incorporated in an appliance having certain extra facilities believed necesssary in a practical ice-cream making machine, provides the basis for a versatile food processor.

According to the invention, domestic food processing apparatus comprises a processing vessel, a drive motor outside ofthe vessel, and transmission means for placing interchangeable processing tools in selective driving engagement with the motor for proces- sing foodstuffs in oradjacentthevessel,whereinthe transmission means comprises an annular drive ring concentrically surrounding the top entrance to the vessel and in driving engagement with said motor, whereby to rotate said ring at low speed and with a high torque, and said processing tools are selectively engageable with said drive ring to process said foodstuffs. Preferably the apparatus contains both refrigeration and heating means respectively to withdraw heat from and apply heat to an outside surface of the vessel.Preferably also the transmission means including the annular drive ring is formed as a su bassembly disengageable from the motor and the vessel.

The annular drive ring can provide most ofthe functions of a conventional bottom drive, without requiring any opening in the processing vessel or any internal obstruction of the vessel, and by use of a simple accessory can also provide most of the functions of a conventional top drive. Additionally, it is uniquely adapted for effective performance of operations in which a scraping orchurning action against the side walls ofthe vessel is required, as in ice-cream making, in which the froze confection should be continuously scraped from the heattransfersurface formed by the vessel wall, as well as in other applications where efficient heat transfer is required, and in other applications where it is desirable to obtain a gentle stirring or churning action, as in butter making.In the context of the invention, low speed of the annulardrive ring means a speed much lower than the shaft speeds of conventional beaters and food processors, typically no more than about 100 rpm and typically about 60 rpm. With such low rotational speeds, a relativelysmall drive motor can develop, with suitable gearing, substantial torque such as is necessaryfor performing some ofthe functions contemplated. Furthermore, the saftey of the device is enhanced because of the low speeds involved.

Furtherfeatures ofthe invention will become apparentfrom the following description of a preferred embodiment with reference to the accompanying drawings, in which: Figure lisa vertical section through an appliance in accordance with the invention, with a transmission unit removed; Figure 2 is a plan view ofthe machine; Figure 3 is an expioded isometric view ofthe transmission unit used on the appliance of Figure 1; Figure4 is an exploded isometric view of parts of an alternative form oftransmission unit; Figures 5a and 5b are respectively isometric and sectional views of a scraper blade forattachmentto the drive of Figure 3;; Figure 6 is an exploded isometric view of an accessoryforproviding high speeddrivetotools requiring overhead drive; Figure7isan explodedisometricviewshowinga juicer accessory; and Figure 8 is an exploded isometric view showing a greater accessory.

Referring to Figures 1 and 2, there is shown apparatus which is a development ofthe ice-cream making machine disclosed in my United States Patent No.4,429,549. To the extentthatthefeatures of the present machine are generally similar to those of my previous apparatus, they will not be described in detail. Thus a body 12 encloses a refrigeration compressor and condenser unit indicated generally by the reference numeral 2, and an evaporator unit 4 surrounds and defines a cylindrical well 18 in the body.Theevaporatoralso incorporates an electrical heating element 6, and the refrigeration unit and the electric heating element are selectively energized and thermostatically controlled underthe supervision of a controi unit 8. An electric drive motor 10 is located alongside the cylindrical well 18.In my earlier machine disclosed in United States Patent No.

4,429,549,a hinged overhead lidforthewell incorporated a transmission which transmitted power fro a vertical shaft of the motorto an overhead drive mechanism engageable with tools descending into the well. Whilst a different drive mechanism is utilized in the presentcase,the present machine has modes of operation similartothose ofthe earlier machine, in thatsuitabletoolsmaybeslowlyorbitedwithin a container 60 located in the well, and refrigeration or gentle heating may be applied to the container. The device may thus be utilized for ice-cream making (when refrigeration is applied) orforthe making or chilling of other confections, orforyogurt making and similar uses if heat is applied. The heater may also be used to free a container 60 frozen into the well by condensed moisture.

In the present case, the hinged lid is replaced by a removable transmission unit 14which drops into a complementary bellows shaped recess 16formed in the uppersurface of the body 12 and surrounding the well 18. A dog 20 in a shaft of the motor 10 projects upwardly at the narrow end ofthis recess. The unit 14 has an annular housing formed by upper and lower members 22,24 secured together by screws 26 and defining annular internal raceways 28 which house and locate an annular drive member30 and ball races 32,34 and 36 which engage the raceways and support the drive memberfor rotation within the housing whilst sustaining axial and radial forces acting on the member. Projecting from the inner periphery ofthe drive member 30 is a drive ring 38 in the form of an annular plate.This plate may be fastto the member 30, but preferably is coupled thereto by an annularfriction clutch (Not shown) housed within the drive member and designed to Iimitthetorquetransmitted from the drive memberto the ringto a predetermined value such asto prevent overloading ofthe motor 10, the dog 20 ofwhich engages a dog 40 atthe bottom of a shaft extension 42 located in the housing of unit 14 by upper and lower bearings 44 and 46. A drive pulley 48 keyed to the shaft extension 42 is coupled to the drive member 30 by a drive belt 50, the ratio ofthe external diameters ofthe pulley 48 and the drive member30 being such asto geardownthe motor speed bya ratio appropriate to the desired rotational speed ofthe ring 38.

In an alternative arrangement shown in Figure 4, the outer peripheries ofthe drive pulley 48 and the member30 are cogged, andthetwo are coupled byan intermediate gear52 supported in the housing bye lay shaft 54 and bearings 56,58.

The recess 16 in the housing is located and configured sothatthe unit 14is located with the drive ring 38 accurately concentric with the well 18 and the container 60.

Figure 5 shows an example of a tool which may be coupled to the drive ring 38, in this case a scraperfor ice-cream making. The scraper has a depending blade 62, which is supported by a curved U-section bracket 63 which embraces a portion 64 (see Fig. 4) oftheinner periphery of the ring 38, vertical pins 66 and 68 bridging the U-section being pressed into bayonet engagement with angled slots B1, B2 in the portion 64 so that upon rotation of the ring 38 in an anticlockwise direction, the scraper is held firmly in place on the ring.

The pin 66 is located so thatthe leading edge 70 ofthe blade engages the wall of container 60, whilst either slot 52 is enlarged or the pin 68 is provided with some floatto allow limited angular movement ofthetrailing edge of the blade relative to the leading edge. Anotch C may be formed in the blade to indicatethe proper level of ice-cream mix to be placed in the container60.

Normallytwo scrapers will be mounted on opposite sides ofthe ring 38.

In orderto stabilize the blades 62 and improve agitation of the m b, a concentric disc 70 (see Figure 1) may be placed at the bottom ofvessel 60 having a central shaft 76 supporting radially extending bottom scraper blades 72 and a paddle 74, the blades 72 being engaged by the blades 62so asto causethem and the paddle74to rotate therewith. By screwing a handle 78 onto the top of shaft 76, means is provided for lifting eitherthe disc 70 and any frozen ice-cream formed above it out ofthe container 60, or by a brief use ofthe heating element 6to release the container60, the entire container 60 and its contents may be lifted out of the machine.

Referring now to Figure 6, an accessory is shown which provides a central overhead drivefora high speed mixing or blending tool. The accessory comprises a disc like epicyclic gear unit 80 which drops into the annular opening formed by the drive member 30 ofthe unit 14. The unit 80 is prevented from rotating by a locking tab 82 which engages a recess 84 in the unit 14 (see Figure 3). The body consists of upper and lower cover plates 88,90 secured together by screws 92,94. An internally toothed ring gear 96 is supported between the plates by ball races 98, and has dogs 100 which engage notches A in the portions 64 (see Figure 4) ofthe drive ring 38, the plate 90 being of sufficiently restricted diameter notto foul the dogs. A planet gear 102 is supported between the plates by a bearing 104 on the screw 92, whilst a sun gear 106 isfastto a shaft 108 supported in the plates 88,90 by bearings 110, 112.Thelowerend ofthe shaftl08 has a socket 114for releasable engagement of rotary tools such as a mixer - 116.

Figure 7 shows a juicer accessory. Astrainer 118 is dropped into the opening formed by drive 38 above the vessel 60 (see Figure 1), followed by a juicer cone 120 having dogs 122 for engagement with the slot in the projections 64 of ring 48 so that the cone will be slowly rotated when the motor 10 is running. A half citrus fruit manually pressed onto the rotating cone will producejuicewhich will run through openings 124 and strainer 118 into the vessel 60.

Figure 8 shows a grating orcuttingattachment which may be placed in the opening ofthe unit 14. An adapterring 130 is engagedwiththe unit 14and receives a rotatable graterof cutter unit 132 which has projecting dogs 134 which can only be pressed downward into engagement with the projections 64 of the drive ring 38 when a guard 136 is in place overthe cutterunit 132. The guard 136 has a chimney 138 through which food to be grated or slice may be fed to the cutter unit.

Itwill be appreciated from theforegoing description of certain purely exemplary tools and accessories that the annular drive of the present invention enables both bottom and overhead drive techniques to be utilised in a food processing unit, whilst avoiding many ofthe disadvantages of these known techniques and providing a particularly robust drive. No shaft passing up through the bottom of the processor chamber is required, nor any hinged mounting for an overhead drive unit. The annular drive described is particularly suited to functions such as ice-cream making, yogurt making and other processes where heat is transferred to and from material being processed, since itfacilitates a scraping action against the walls ofthevesseel,thus maximising heat transfer.

Claims (11)

1. A domestic food processing apparatus comprising a body containing a processing vessel and a drive motor outside ofthevessel, and interchangeable processing tools in selective driving engagement with the motor for procressing foodstuffs on entryto or within the vessel, wherein an annular drive ring is provided concentrically surrounding a top entrance to the vessel and in driving engagement with said motor whereby to rotate said ring at low speed and with a high torque and said processing tools are selectively engageable with said drive ring to process said foodstuffs.

2. Apparatus according to Claim 1,furthercom- prising refrigeration means to withdraw heatfrom an outside surface of said vessel.

3. Apparatus according to Claim 1, furthercom- prising heating means to apply heat to an outside surface of said vessel.

4. Apparatus according to Claim 1, wherein said annular drive ring is located in an assembly disen gageabiefrom said motor and said vessel.

5. Apparatus according to Claim 1, further including a gear assembly engageable concentrically within said drive ring to provide step up gearing for at least one coupling to at least one processing tool extending downwardly into said vessel.

6. Apparatus according to Claim 1, wherein at least certain of said tools are releasably coupled directly to said drive ring and extend downwardly into said vessel adjacent its walls.

7. Apparatus according to Claim 1, wherein at least one of said tools is supported by said drive ring across the entrance to said vessel, and has processing means engageabie with foodstuffs applied to its upper surface and apertures therein permitting passage of processed material into said vessel.

8. Apparatus according to Claim 7, wherein the processing means is a central ribbed and domed citrus juicer, and the apertures are straining apertures formed in a radial supportforthejuicer, said radial support being in driving engagement with the annular drive ring.

9. Apparatus according to Claim 7, wherein the processing means is a disc-like rotary slicing, shredding or rasping tool in peripheral driving engagement with the annular drive ring.

10. Apparatus according to Claim 6, wherein the releasably coupled tools comprise at least one scraper blade configured to engage a cylindrical sidewall of the vessel.

11. Apparatus according to Claim 6 or 10, further including product extraction means, comprising a base plate standing freely on the bottom ofthevessel, and a vertical column extending upwardlyto a handle above the annular drive ring.