GB2525439A

GB2525439A - Monitor

Info

Publication number: GB2525439A
Application number: GB1407339.9A
Authority: GB
Inventors: James Hinchliffe; Patrick Storey
Original assignee: TOM CHANDLEY Ltd
Current assignee: TOM CHANDLEY Ltd
Priority date: 2014-04-25
Filing date: 2014-04-25
Publication date: 2015-10-28
Also published as: GB201407339D0

Abstract

A monitor measures the temperature of a controller for a cooking appliance 1, which has an electrical supply. The monitor comprises a temperature sensor 13, an alarm and means to operatively connect the monitor to the controller of a cooking appliance 11. The monitor is arranged in use to monitor the temperature of the controller or its surrounding environment 9 and to activate the alarm if the temperature exceeds a first threshold temperature. It overrides operation of the cooking appliance if the temperature exceeds a second threshold temperature, thereby reducing the risk of the controller or other electrical components of the cooking appliance being damaged by heat from the cooking appliances heating elements 7.

Description

MONITOR

Technical Field of the Invention

The present invention relates to a monitor for a cooking appliance.

Background to the Invention

Industrial cooking appliances such as large scale baking ovens are used in retail stores to provide fresh baked goods to consumers quickly and efficiently. An industrial baking oven typically comprises a main oven body defining a cavity in which one or more racks are mounted. The main oven body comprises one or more heating devices that raise the temperature of the cavity environment and, thus, bake any food supported on the racks contained within the body.

An electrical control chassis is usually mounted adjacent the main oven body in a self-contained unit, The electrical control chassis comprises a programmable logic controller or PLC which controls all oven operations. Given the proximity of the electrical control chassis to the main oven body, a problem with conventional industrial cooking appliances such as these is that the electrical control chassis canbecome very hot due to heat transfer from the main oven body and this can have a detrimental effect on the electronics contained within, Over exposure to these raised temperature conditions can damage the electronics and affect the operation of the oven, This is undesirable since it can lead to downtime whilst the oven is repaired thereby impacting upon sales of baked goods. There is also a cost associated with repairing the oven, One existing method of trying to reduce the exposure of the chassis to raised temperature conditions includes insulating the electrical control chassis from the main oven body. However, even with insulation, the electrical control chassis can still become damaged through exposure to raised temperature conditions. Increasing the amount of insulating material to try to reduce exposure of the chassis to raised temperature conditions increases the footprint of the oven which is undesirable. Another attempted solution includes separating the elecifical control chassis from the main oven body but this is not possible where a self-contained oven unit is desired and it also increases the cost and complexity of manufacture, Embodiments of the present invention have been made in consideration of these problems.

Summary of the Invention

According to a first aspect of the present invention, there is provided a monitor for measuring the temperature of a controller for a cooking appliance comprising a temperature sensor, an aami and means to operatively connect the monitor to the controller of a cooking appliance, wherein the monitor is arranged in use to monitor the temperature of the controller or its surrounding environment and to activate the alarm if the temperature exceeds a first threshold temperature and to overide operation of the cooking appliance if the temperature exceeds a second threshold temperature, thereby to reduce the risk of the controller being damaged by heat from the cooking appliance.

Advantageously, by alerting a user when the temperature of the controller or surrounding environment exceeds a first threshold temperature, the user can intervene to prevent damage to the electrical components within the chassis, By overriding operation ofthe cooking appliance when a measured temperature ofthe controller or environment exceeds a second unsafe temperature, damage to the controller can be averted where, for example, a user is not present to intervene when the temperature has exceeded the first threshold temperature.

The monitor may be arranged to switch off the electrical supply of the cooking appliance if the temperature exceeds the second threshold temperature.

The alarm may comprise an audible signal and/or a visual signal.

The monitor may further comprise a communications port to enable one or more alarms to be transmitted to a remote device. The monitor may further comprise a user interface to enable desired values for the first threshold temperature arid the second threshold temperature to be set.

According to a second aspect of the present invention, there is provided a cooking appliance comprising a monitor according to the first aspect.

According to a third aspect of the present invention, there is provided an oven comprising a control chassis, a controller mounted to the control chassis and a monitor according to the first aspect, wherein the monitor is arranged in use to monitor the temperature of the control chassis.

According to a fourth aspect of the present invention, there is provided a controller for a cooking appliance comprising a monitoring arrangement having a temperature sensor and an alarm, wherein the temperature sensor is arranged in use to monitor temperature of the controller or its environment and to cause the controller to activate the alarm if the temperature exceeds a first threshold temperature and to override operation of the cooking appliance if the temperature exceeds a second threshold temperature, thereby to reduce the risk ofthe controller being damaged by heat from the cooking appliance.

The controller may be aranged to switch off the electrical supply of the cooking appliance if the temperature exceeds the second threshold temperature.

The alarm may comprise an audible signal and/or a visual signal.

The controller may further comprise a communications port to enable one or more alarms to be transmitted to a remote device.

The controller may ifirther compri sea user interface to enable desired values for the first threshold temperature and the second threshold temperature to be set.

According to a fifth aspect of the present invention, there is provided a cooking appliance comprising a controller according to the fourth aspect.

According to a sixth aspect of the present invention, there is provided an oven comprising a control chassis and a controller according to the fourth aspect mounted to the control chassis, wherein the temperature sensor is arranged in use to monitor the temperature of the control chassis.

Detailed Description of the Invention

In order that the invention may be more clearly understood an embodiment thereof will now be described, by way of example only, with reference to the accompanying drawings, of which: Figure 1 is a schematic view of an oven comprising a cooking appliance monitor according to the invention; Figure 2 is a schematic view of a cooking appliance monitor according to the invention; and

S

Figure 3 is a schematic view of a graphical user interface used as part of the cooking appliance monitor shown in Figure 2.

With reference to the drawings there is shown a cooking appliance I comprising a stainless steel outer shell 3 having a baking chamber 5 defined therein. A plurality of heating elements 7 is mounted within the baking chamber and arranged to raise the temperature of the internal environment of the chamber 5 when in use.

An electrical control chassis 9 is incorporated into the outer shell 3, adjacent the chamberS, The control chassis houses a programmable logic controller or PLC I which controls the operation of the heating elements 7 and, hence, the temperature of the environment within the chamber 5. The chassis 9 has a pair of cooling fans to help regulate the temperature of the chassis 9 and keep the internal environment within acceptable limits for the &ectronics contained therein. The PLC 11 has a timer to enable the operation of the oven to be controlled for a desired length of time depending upon the IS baking requirements. The PLC 11 is connected to an LCD display 12 to allow the operational status of the oven to be monitored such as the oven temperature and elapsed cooking time. The display 12 comprises a touchscreen to enable user interaction with the PLC 11 to control the cooking parameters of the oven amongst other functions.

A thermistor based temperature sensor 13 is connected to the PLC 11 and is arranged to measure the average air temperature ofthe chassis 9. The sensor is positioned substantially centrally within the chassis 9 and is arranged to measure the airtemperature of the chassis 9 every second so that real time measurements can be fed back to the PLC 11 for processing. Part of the sensor 13 is encapsulated within a metal box to protect the sensor from external damage. The sensing part ofthe sensor 13 is exposed outside ofthe box within the chassis 9 to enable measurements to be taken.

The PLC 11 is programmable to switch off the electrical supply to the baking chamber 5 depending upon the measured temperature of the chassis 9. The PLC 11 is programmed to generate a warning signal when the measured temperature of the chassis 9 exceeds a first threshold temperature. The warning signal comprises a visual alert which is displayed on the oven display screen but it may also comprise an audible alert, The PLC II may also comprise a communications port to enable the PLC to be connected to a wired or wireless network so that an alert signal can be sent remotely, for example, to a remote device of an equipment supervisor or engineer.

The PLC II is frirther programmable to switch off the electrical supply to the baking chamber S when the measured temperature of the chassis 9 exceeds a second threshold temperature. This temperature is a temperature at which damage to the PLC II and other electronic equipment within the chassis 9 may occur if the chassis 9 is exposed to temperatures above the threshold temperature for extended periods of time, The PLC 11 comprises software to enable a user to interface with the PLC 11 and control the operation of the oven via the touchscreen display U. The graphical user interface comprises an activation option to enable the chassis temperature monitoring sensor to be activated, The interface also comprises input fields to enable a chassis warning temperature to be set and a chassis over temperature to be set. The warning temperature is the first threshold temperature which activates a warning signal and the chassis over temperature is the second threshold temperature which may result in ceasing of operation of the heating elements 7. A second activation option is provided which dictates whether or not breaching the chassis over temperature results in switching offthe electrical supply of the backing chamber 5.

In use, a user inputs a chassis warning temperature via the graphical user interface. The input temperature corresponds to a temperature above which the user wishes to be alerted so that intervening action can be taken to prevent damage to the electronics within the chassis. A temperature value is also input for the chassis over temperature. This temperature value corresponds to a temperature above which the user may wish the electrical supply of the baking chamber 5 of the oven to be switched off due to a likelihood of severe damage to the electronics within the chassis 9. If the user would like the electrical supply of the oven to be switched off when the chassis temperature exceeds this threshold temperature, the user selects YES' from the two available options. When all desired values have been input, the user activates the chassis sensor t3 by selecting YES' from the options menu for that control.

Having set all desired parameters for the chassis warning system, the oven is activated and baking of goods may commence. The sensor 13 provides electronic chassis temperature readings to the PLC 11 during cooking time. If the chassis temperature exceeds the first threshold temperature, the warning signal is activated and a user can take measures to reduce the chassis temperature. If the chassis temperature exceeds the second threshold temperature, if the user has selected the deactivation option, the PLC 11 will switch off the electrical supply to the baking chamber, thus overriding operation of the oven, until the chassis temperature has dropped below the second threshold temperature or the user manually reactivates the oven.

The above embodiment is described by way of example only. Many variations are possible without departing from the scope of the invention as defined in the appended claims.

For example, the oven may comprise more than one baking chamber or deck for simultaneously baking a range of different goods. In this embodiment, there is a PLC Ill associated with each deck to enable independent operation of the decks. Each PLC is housed within a common chassis 109 and one of the PLCs may be assigned a master' status and be arranged to monitor the temperature of the common chassis 109 via the temperature sensor 113. The masterPLC is arranged to transmit the temperature readings to the other PLCs using the CAN bus protocol. The PLC 111 may be arranged to isolate all oven decks from the mains supply.

Claims

CLAIMS1 A monitor for measuring the temperature of a controller for a cooking appliance hang an electrical supply, the monitor comprising a temperature sensor, an alarm and means to operatively connect the monitor to the controller of a cooking appliance, wherein the monitor is arranged in use to monitor the temperature of the controller or its surrounding environment and to activate the alarm if the temperature exceeds a first threshold temperature and to override operation of the cooking appliance if the temperature exceeds a second threshold temperature, thereby to reduce the risk of the controller or other electrical components of the cooking appliance being damaged by heat from the cooking appliance.
2. A monitor as claimed in claim 1, wherein the monitor is arranged to switch off the electrical supply of the cooking appliance if the temperature exceeds the second threshold temperature.
3, A monitor as claimed in any preceding claim, wherein the alarm comprises an IS audible signal and/or a visual signal.
4. A monitor as claimed in any preceding claim, further comprising a communications port to enable one or more alarms to be transmitted to a remote device.
5. A monitor as claimed in any preceding claim, further comprising a user interface to enable desired values for the first threshold temperature and the second threshold temperature to be set.
6. A monitor as substantially hereinbefore described with reference to the accompanying drawings.
7. A cooking appliance comprising a monitor according to any preceding claim.
8. An oven comprising a control chassis, a controller mounted to the control chassis and a monitor according to any of claims I to 6, wherein the monitor is arranged in use to monitor the temperature of the control chassis.
9. A controller for a cooking appliance having an electrical supply, the controller comprising a monitoring arrangement having a temperature sensor and an alarm, wherein the temperature sensor is arranged in use to monitor temperature of the controller or its environment and to cause the controller to activate the alanu if the temperature exceeds a first threshold temperature and to override operation of the cooking appliance ifthe temperature exceeds a second thresholdtemperature, thereby to reduce the risk of damage to the controller or other electrical components of the cooking appliance by heat from the cooking appliance.
10. A controller as claimed in claim 9, wherein the controller is arranged to switch off the electrical supply of the cooking appliance if the temperature exceeds the second threshold temperature.
11. A controller as claimed in claim 9 or claim 10, wherein the alarm comprises an audible signal and/or a visual signal.
12. A controller as claimed in any one of claims 9 to 11, further comprising a communications port to enable one or more alarms to be transmitted to a remote device.
13. A controller as claimed in any one of claims 9 to 12, further comprising a user interface to enable desired values for the first threshold temperature and the second threshold temperature to be set. IiN, A controHer as substantiaHy hereinbefore described with reference to the accompanying drawings.5. A cooking appliance comprising a controller according to any of claims 9 to
14.16. An oven comprising a control chassis and a controller as claimed in any ofclaims 9 to 14 mounted to the control chassis, wherein the temperature sensor is arranged in use to monitor the temperature of the control chassis.