WO2005082212A1

WO2005082212A1 - Contact grills

Info

Publication number: WO2005082212A1
Application number: PCT/GB2005/000664
Authority: WO
Inventors: Deryck Gaffney; Duncan Gaffney
Original assignee: Rockwell Mckenna Holdings Uk Limited
Priority date: 2004-02-24
Filing date: 2005-02-23
Publication date: 2005-09-09
Also published as: GB2411342A; GB0404008D0

Abstract

An automated contact grill for items of food comprises a casing (1) including a loading chamber (2) for receiving items of food to be grilled, a heating chamber (7) separated from the loading chamber (2) by a partition (8) which can selectively be opened or closed to provide access to the heating chamber (7) or to prevent such access, and a delivery surface (3) onto which items of grilled food are discharged from the heating chamber (7). The heating chamber (7) houses two electrically heated grill plates (9,10) positioned one above the other and transfer means are provided for causing items of food to be moved from the loading means and onto the lower grill plate (9) when the partition is in its open position. The upper grill plate (10) is movable from a rest position relatively remote from the lower grill plate (9) to a grilling position relatively close to the lower grill plate (9) following closure of the partition (8). Means are provided for moving the upper grill plate (10) to its rest position after a predetermined period of time together with means for delivering grilled food items from the lower grill plate (9) to the delivery surface (3) of the contact grill.

Description

CONTACT GRILLS

This invention relates to contact grills and more especially, but not exclusively, to fully automated contact grills for use by the general public without supervision in a self-service environment.

Contact grills for grilling or toasting food items such as sandwiches are well known. These grills conventionally include a pair of vertically spaced grill plates, the lowermost grill plate of the pair being fixed and the uppermost grill plate or plates being movable downwardly and into contact with the upper surface of an item of food placed on the lowermost plate. Whereas these grills are commonly to be found in catering and domestic environments, they are unsuitable for self-service operation because of inherent safety hazards. In practice, therefore, selected sandwiches and items of panini and ciabatta are grilled or toasted at the request of a customer by trained personnel.

It is also known to incorporate contact grills into automated vending machines which are preloaded with a limited range of uncooked pre-packaged food items. Such machines are more acceptable for reasons of safety but suffer from the disadvantage that the range of products available to consumers is extremely limited.

The use of microwave ovens in self-service environments has increased substantially over the past twenty and more years because of the rise in popularity and enhanced safety of such ovens. Such environments include those in which items of pre-packaged food are selected by a consumer and heated or cooked on-site by the consumer for subsequent consumption. With appropriate improvements in safety, it is considered that, in time, contact grills will be available for use by customers without supervision in self-service environments. It is, therefore, one object of the present invention to provide a contact grill which can be used safely by a consumer to grill or toast a selected food item. The words "grill" or "toast" are used to describe a cooking process in which opposite sides of a food item are cooked by a grilling or toasting process. For the sake of simplicity, the words "grill" or "grilling" are used herein to describe this process.

Another object of the invention is to provide a fully automated contact grill capable of operation by a consumer, the contact grill operating automatically to grill a selected one of a range of pre-packaged food items in response to data or instructions inputted by a user through a machine readable code, a programmable touch pad or the like.

In one aspect, the invention provides an automated contact grill for items of food, the contact grill comprising a casing including a loading chamber for receiving items of food to be grilled, a heating chamber separated from the loading chamber by a partition which can selectively be opened or closed to provide access to the heating chamber or to prevent such access, and a delivery surface onto which items of grilled food are discharged from the heating chamber, the heating chamber housing two electrically heated grill plates positioned one above the other, transfer means for causing items of food to be moved from the loading means and onto the lower grill plate when the partition is in its open position, means for moving the upper grill plate from a rest position relatively remote from the lower grill plate to a grilling position relatively close to the lower grill plate following closure of the partition, means for moving the upper grill plate to its rest position after a predetermined period of time, and means for delivering grilled food items from the lower grill plate to the delivery surface of the contact grill.

In a preferred arrangement, the lower grill plate is stationary during operation of the contact grill. Preferably, the upper grill plate is moved downwardly into contact with an upper surface of a food item for grilling purposes.

The loading chamber may comprise a closable chamber comprising a loading surface onto which food items to be grilled can be placed and a pivotable cover movable between an open position in which access to the loading surface is possible and a closed position in which such access is prevented. A drive motor may be provided to impart movement to the cover between its open and closed positions. In its closed position, the cover may be locked. The loading surface and the upper surface of the lower grill plate may lie in the same or substantially the same planes. In use of the contact grill, this plane is preferably horizontal or substantially so. The loading surface and the upper surface of the lower grill plate are, however, preferably spaced apart to inhibit the transfer of heat from the grill plate to the loading surface.

The transfer means may comprise a member movable selectively between a rest position in which it is located within the cover of the loading chamber and a delivery position on or immediately above the upper surface of the lower grill plate, the member being in its rest position during the grilling process. The member may comprise an arm connected to a drive conveyor and operable to make contact with and impart movement to a food item to be grilled. The drive conveyor typically comprises on or more continuous chains movable by motor driven cogs supported from the side walls of the casing.

In an alternative embodiment, the drive conveyor comprises a pair of continuous belts each movable by a motor driven roller of a pair of such rollers supported from the side walls of the casing. In this arrangement, the sides of the arm are supported by the belts and the arm is moved between its rest position and its other position within the heating chamber. The means for moving the upper grill plate preferably comprises an electric motor connected to impart movement to a support to which the upper grill plate is secured. The support may comprise an upstanding spindle secured to an upper surface of the upper grill plate and movable in a vertically or substantially vertical direction by a shaft driven by the electric motor.

The grill plates may be heated by thermostatically controlled electric elements and may be produced from, for example, stainless steel, brass, cast iron or other material having the required thermal conductive properties which enable the grill plates to be repeatedly heated to a high temperature comparable with grilling and to retain their heat over long periods of time.

The casing which houses the heating chamber may be produced from steel or other suitable material capable of preventing a user from accessing any potentially harmful components.

Operation of the grilling cycle may be controlled remotely by a site operator or by a user operating selected buttons, touch pads and/or controls located on an exposed surface of the grill casing. Alternatively, operation of the grilling cycle may be effected via machine readable encrypted data (e.g. a bar code, microchip or infrared readable code) forming part of or attached to packaging for a selected food item. In this latter case, a user simply passes the encrypted data of a selected food item across the face of a data reader and then places the food item onto the loading surface. The grilling cycle is then started. In each case, input by the user of specified data unique to a particular food item causes not only the grilling cycle to be initiated once the food item is placed on the loading surface, but also causes the upper grill plate to move downwardly by a distance such that it makes adequate contact with the upper surface of the food item, and then to move upwardly away from this surface after a predetermined period of time. The means for delivering grilled food items to the delivery surface of the grill may comprise an inclined chute positioned below the lower grill plate with its upper end positioned beyond the end of the lower grill plate remote from the partition, the lowermost end of the chute being in communication with the delivery surface. Grilled food items may be moved towards and over the end of the lower grill plate and onto the chute surface through operation of the arm and drive conveyor referred to above.

The items of food may, for example, comprise sandwiches, panini and ciabetta items, filled bread rolls and the like. Food items to be grilled may be pre-packaged in heat-resistant, food grade paper.

A fan may be positioned within the heating chamber to encourage air circulation and vents may be located in one or more walls of the casing for heating venting purposes.

The invention will now be described by way of example only with reference to the accompanying diagrammatic drawings, in which :-

Figure 1 is an isometric view of a contact grill in accordance with the invention;

Figure 2 is a front view of the grill shown in Figure 1; and

Figure 3 is in section taken along line III-III of Figure 2.

The illustrated contact grill comprises an outer casing 1 having, for example, a steel frame covered with steel panels. Vents (not shown) may be positioned in the rear, top or side panels of the casing for ventilation purposes. Protruding from the front panel of the casing is a loading chamber 2 and a delivery tray 3. The loading chamber includes a generally flat and horizontal loading surface 4 covered by a hinged cover 5. The cover is hinged along its upper edge adjacent to the casing front panel and is movable between a raised position in which access to the loading surface 4 is possible and a closed position (as shown in Figure 3) in which such access is prevented. A motor 6 is provided to move the cover between its open and closed positions. When closed, the cover is preferably locked automatically and cannot be opened by hand. The lock may, for example, be electrically released.

The interior of the casing defines a heating chamber 7 in which grilling of food items can be effected. Entry into the chamber 7 is via a partition 8 movable from a rest position as shown and an open position in which the partition is lifted away from the loading surface 4 by an electric motor 11.

Positioned within the heating chamber is a pair of thermostatically controlled electric grill plates 9, 10. These plates 9, 10 are produced from stainless steel, brass or cast iron or indeed any other material having the required thermal conductivity properties which enable the plates to be heated respectively to relatively high grilling temperatures and/or to be maintained at such temperatures for lengthy periods of time. Typically, the grill plates are heated by electrical, dry resistor elements mounted within the heating chamber. Grill plate 9 is positioned below grill plate 10 and is permanently fixed in the position shown in Figure 3. Upper grill plate 10 is movable through an electric motor 12 and a movement mechanism 14 between upstanding guides 13 towards and away from grill plate 9. In an alternative arrangement, no upstanding guides are provided. The mechanism 14 comprises a drive shaft 15 connected to the motor 12, and an upstanding spindle 16 driven by the shaft 15. The lower end of the spindle 16 is secured to an upper surface of the upper grill plate 10. The movement mechanism operates to move the upper grill plate 10 between its rest position as shown in Figure 3 in which it is relatively remote from the lower grill plate 9, and an operating position in which the grill plate 10 is relatively close to the lower grill plate. In use, in its lowermost position the lower surface of the grill plate 10 will rest on the upper surface of the food item to be grilled. The distance between the plates in this position will, therefore, depend on the thickness of the food item.

Both grill plates 9, 10 lie in horizontal planes, that of the upper grill plate 10 being maintained by the movement mechanism 14 and the guides 13.

As will be seen from Figure 3, the lower grill plate 9 and the loading surface 4 lie in the same or substantially the same plane. This facilitates easy transfer of food items from the loading surface to the lower grill plate. The neighbouring edges of the plate 9 and the loading surface 4 are, however, spaced apart to inhibit the transfer of heat from one to the other.

An inclined chute 17 is positioned below the lower grill plate 9 with its uppermost surface beyond the end of the plate 9 remote from the partition 8. The lower end of the chute 17 is in communication with the delivery tray 3.

A fan 19 is mounted on the rear panel of the casing to circulate air within the heating chamber.

Positioned within the loading chamber 2 is an upstanding conveyor arm 18. This arm is movable into and out of the heating chamber by one or more continuous chains 20 (only one of which is shown) operated by a reversible electric motor 21. The chain passes around cogs 22, the rearmost arms of which are driven by the motor 21. The arm extends across the full width of the heating chamber 7 and the loading chamber 2 and is connected at its ends to the transmission chain 20. The arm is positioned above the loading surface 4 and, consequently, the lower grill plate 10 by a guide channel cut into the steel sub-frame. In use, the arm effectively drags a food item to be grilled from the loading surface to the lower grill plate; and after completion of the grilling process, drags the grilled food item over the end of the grill plate 10 remote from the partition and onto the inclined surface of the chute 17. Thus, the arm 18 is provided firstly to move uncooked food items from the loading chamber through the partition 8 and into the heating chamber; and secondly to move grilled food items over the far edge of the lower grill plate and onto the surface of the inclined chute 17. The rest position of the arm 18 is within the loading chamber, the arm returning to its rest position during grilling of a food item.

As will be seen from Figure 2, the front of the contact grill includes a control panel including a bar code reader 22, a display 23, programming keys 24, a start key 25, an ON-OFF switch 26, and an ON-OFF pilot light 27. The contact grill may also include a standard keypad (not shown) via which information may be entered manually by the user. Through these items, automated control of the contact grill can be effected.

All external panels of the casing are insulated or suitably located to ensure that any thermal conductivity from the hot compartments of the heating chamber is not transferred to the external panels of the contact grill.

A consumer wishing to use the described contact grill selects a food item (a sandwich for ease of description) from an extensive range and approaches the contact grill. The sandwich is pre-packaged in heat resistant food grade paper. Before operating the contact grill, the consumer may be required to enter a code given to him/her by an operative. This prevents accidental interference with preset cooking parameters. If the packaging includes machine readable data in the form of a bar code, that part of the packaging carrying the bar code is scanned across the bar code reader 23 to enable appropriate grill times and other relevant information to be inputted to the grill controls. The cover 5 then opens automatically (or may be lifted manually when unloaded) to enable the consumer to place the selected sandwich on the loading surface 4. The cover then closes and the consumer presses the start button 25. This causes the partition 8 to be raised automatically by the motor 11 and the sandwich moved by the arm 18 into the heating chamber 7 and onto the upper surface of the lower grill plate 9. The partition may then close or remain open. The upper grill plate 10 is automatically lowered from its rest position dictated by the inputted data and equating to a position to its grilling position in which it lies in contact with the upper surface of the sandwich. The plates are activated for a time period dependent on the inputted encrypted data to grill the two sides of the sandwich. The grill plates are then deactivated and the upper plate 10 raised to its rest position. The partition 8 then opens (if closed) to enable the arm 8 to enter the heating chamber 7 and move the grilled sandwich off the far edge of the lower grill plate 9 and onto the inclined surface of the chute 17. The ejected sandwich is then presented to the consumer on the delivery tray. At the same time, the arm 8 is retracted to its rest position within the loading chamber.

During the grilling process, the consumer is made aware of the progress of the sandwich through the contact grill through messages appearing on the display 23. The ON-OFF pilot light 27 is used to inform potential consumers whether or not the contact grill is available for use.

In an alternative embodiment (not shown), once the grill plates 9, 10 are deactivated (i.e. once the sandwich has been grilled), the arm 8 enters the heating chamber 7 to move the grilled sandwich off the edge of the lower grill plate 9 and back onto the loading surface 4 whereupon the grilled sandwich can be presented back to the consumer.

In other words, the loading surface 4 is not only the surface to allow input of a sandwich into the heating chamber but also the delivery surface from which the resulting grilled sandwich can then be accessed by the consumer.

In a further embodiment (not shown) the loading chamber 2 includes a sensor to sense the presence of a food item within the chamber 2. The sensor may, for example, be an infra-red or pressure sensor. Once the presence of a food item is sensed, the grill may commence automatically, preferably after a pre-determined time delay. The sensor may also prevent a food item being presented to a consumer until access is safe.

The sensor may include a bar code reader to input information from a bar code located on the food packaging without the need for the data to be inputted through the control panel.

In a further embodiment (also not shown) the arm 8 may have a scouring brush or the like attached thereto to scrape and clean the surface of the lower trill plate 9 during use. The plates 9, 10 may be removable from the grill, once cooled to an appropriate temperature, to allow them to be cleaned. This would enable sandwiches to be grilled which are not pre-packed.

One or both grill plates 9, 10 may have ridges or an otherwise uneven surface.

The data processing unit of the grill may include a modem to allow access to the control software through an Internet link. As such, any faults within the control software may be investigated and rectified remotely. It will be appreciated that the foregoing is merely exemplary of contact grills in accordance with the invention and that various modifications can readily be made thereto without departing from the true scope of the invention.

Claims

An automated contact grill for items of food, the contact grill comprising a casing including a loading chamber for receiving items of food to be grilled, a heating chamber separated from the loading chamber by a partition which can selectively be opened or closed to provide access to the heating chamber or to prevent such access, and a delivery surface onto which items of grilled food are discharged from the heating chamber, the heating chamber housing two electrically heated grill plates positioned one above the other, transfer means for causing items of food to be moved from the loading means and onto the lower grill plate when the partition is in its open position, means for moving the upper grill plate from a rest position relatively remote from the lower grill plate to a grilling position relatively close to the lower grill plate following closure of the partition, means for moving the upper grill plate to its rest position after a predetermined period of time, and means for delivering grilled food items from the lower grill plate to the delivery surface of the contact grill.

A grill as claimed in claim 1 wherein the lower grill plate is stationary during operation of the contact grill.

A grill as claimed in claim 1 or claim 2 wherein the upper grill plate is moved downwardly into contact with an upper surface of a food item for grilling purposes.

A grill as claimed in any one of the preceding claims wherein the loading chamber comprises a closable chamber comprising a loading surface onto which food items to be grilled can be placed and a pivotable cover movable between an open position in which access to the loading surface is possible and a closed position in which such access is prevented.

5. A grill as claimed in any one of the preceding claims wherein a drive motor is provided to impart movement to the cover between its open and closed positions.

6. A grill as claimed in any one of the preceding claims wherein, in its closed position, the cover is locked.

7. A grill as claimed in any one of the preceding claims wherein the loading surface and the upper surface of the lower grill plate lie in the same or substantially the same planes.

8. A grill as claimed in claim 7 wherein, in use of the contact grill, the plane is horizontal or substantially so.

9. A grill as claimed in any one of the preceding claims wherein the loading surface and the upper surface of the lower grill plate are preferably spaced apart to inhibit the transfer of heat from the grill plate to the loading surface.

10. A grill as claimed in any one of the preceding claims wherein the transfer means comprises a member movable selectively between a rest position in which it is located within the cover of the loading chamber and a delivery position on or immediately above the upper surface of the lower grill plate, the member being in its rest position during the grilling process.

11. A grill as claimed in claim 10 wherein the member comprises an arm connected to a drive conveyor and operable to make contact with and impart movement to a food item to be grilled.

12. A grill as claimed in claim 11 wherein the drive conveyor comprises one or more continuous chains movable by motor driven cogs supported from the side walls of the casing.

13. A grill as claimed in claim 11 wherein the drive conveyor comprises a pair of continuous belts each movable by a motor driven roller of a pair of such rollers supported from the side walls of the casing.

14. A grill as claimed in claim 13 wherein the sides of the arm are supported by the belts and the arm is moved between its rest position and its other position within the heating chamber.

15. A grill as claimed in any one of the preceding claims wherein the means for moving the upper grill plate comprises an electric motor connected to impart movement to a support to which the upper grill plate is secured.

16. A grill as claimed in claim 15 wherein he support comprises an upstanding spindle secured to an upper surface of the upper grill plate and movable in a vertically or substantially vertical direction by a shaft driven by the electric motor.

17. A grill as claimed in any one of the preceding claims wherein the grill plates are heated by thermostatically controlled electric elements and are produced from stainless steel or brass or cast iron or other material having the required thermal conductive properties to enable the grill plates to be repeatedly heated to a high temperature comparable with grilling and to retain their heat over long periods of time.

18. A grill as claimed in any one of the preceding claims in which operation of the grilling cycle may be controlled remotely by a site operator or by a user operating selected buttons, touch pads and/or controls located on an exposed surface of the grill casing.

19. A grill as claimed in any one of claims 1 to 17 in which operation of the grilling cycle is effected via machine readable encrypted data forming part of or attached to packaging for a selected food item.

20. A grill as claimed in any one of the preceding claims wherein the means for delivering grilled food items to the delivery surface of the grill comprises an inclined chute positioned below the lower grill plate with its upper end positioned beyond the end of the lower grill plate remote from the partition, the lowermost end of the chute being in communication with the delivery surface.

21. A grill as claimed in any one of the preceding claims in which a fan is positioned within the heating chamber to encourage air circulation and vents may be located in one or more walls of the casing for heating venting purposes.