Temperature controlled probe assembly

In a method for heating articles to an elevated set point temperature within a heating chamber of a furnace through which the articles are moved, and comprising the steps of:

• applying thermal energy within the chamber to heat the articles;
• measuring the temperature of the articles by contacting the articles with a set of thermocouple probe rods;
• and
• adjusting the amount of applied energy in accordance with the measured articles temperature so as to adjust the temperature of the articles toward the set point temperature;
• the improvement wherein the method further comprises the steps of:
• measuring the temperature of the environment surrounding the thermocouple probe rods or the temperature of the actual thermocouple probe rods;
• supplying cooling air to the thermocouple probe rods when the environmental temperature is greater than a predetermined temperature;
• and
• adjusting the flow of supplied cooling air to the thermocouple probe rods in accordance with the amount of thermal energy being applied to the articles.

In a furnace for heating articles to an elevated set point temperature and comprising a heating chamber through which the articles are moved, combustion means for generating and applying thermal energy within the heating chamber to heat the articles, combustion air supply means for supplying air to the combustion means, and thermocouple probe means including thermocouple probe rods for contacting the articles and measuring the temperature of the articles so as to regulate the energy applied to the articles by the combustion means, the improvement which comprises:

• environmental temperature measuring means for measuring the temperature of the environment surrounding the thermocouple probe rods or the temperature of the actual thermocouple probe rods, and for generating an environmental temperature signal representative of the measuring environmental temperature;
• cooling air supply means responsive to the environmental temperature signal for selectively supplying cooling air to the thermocouple probe rods in accordance with the difference between the environmental temperature and a predetermined temperature;
• and
• the thermocouple probe means further comprises a probe carriage comprising:
• an elongated barrel having an air chamber and an insulative section adjacent the air chamber, and wherein the thermocouple probe rods extend longitudinally through the barrel;
• air channels extending through the insulative section and in which the thermocouple probe rods are received;
• and
• collar means for maintaining communicative openings between the air channels and the air chamber.

In a furnace for heating articles to an elevated set point temperature and comprising a heating chamber through which the articles are moved, combustion means for generating and applying thermal energy within the heating chamber to heat the articles, combustion air supply means for supplying air to the combustion means, probe mounting means movable between an extended position and a retracted position, and thermocouple probe rods supported by the probe mounting means for contacting the articles when the mounting means is in an extended position and for measuring the temperature of the articles, the improvement comprising:

• air channels at least partially surrounding the thermocouple probe rods;
• means communicating with the air channels to supply cooling air to the thermocouple probe rods;
• and
• regulator means for regulating the amount of supplied cooling air to the thermocouple probe rods in accordance with the combustion rate of the combustion means.

In a method for heating articles to an elevated set point temperature within a heating chamber of a furnace through which the articles are moved, and comprising the steps of:

• supplying air to a combustion device to generate thermal energy;
• applying the thermal energy within the chamber to heat the articles;
• measuring the temperature of the articles by contacting the articles with a set of thermocouple probe rods;
• and
• adjusting the amount of applied energy in accordance with the measured article temperature so as to adjust the temperature of the articles toward the set point temperature;
• the improvement wherein the method further comprises the steps of:
• supplying cooling air to the thermocouple probe rods;
• and
• regulating the amount of supplied cooling air to the thermocouple probe rods in accordance with the combustion rate of the combustion device.