Method and apparatus for cooling a tool

A method of cooling a tool in a heat-treatment furnace, the method comprising the step of:

• providing an electrical control valve for connecting a feed of the tool either to an output line of a coolant supply or to a municipal water system;
• providing another electrical control valve for connecting a return of the tool either with an intake line of the coolant supply or to a municipal sewage system;
• during normal cooling operation setting the control valves with electricity into and holding them electrically in a first position in which coolant is fed from the output line of the coolant supply to the tool and from the tool via the return back to the coolant supply;
• on interruption of electric supply to the control valves, automatically returning the control valves into an emergency position in which cold water is fed from the municipal water supply to the tool, then through the tool, and thence via the return to a drain of the municipal sewage system;
• biasing the control valves by a spring force into the emergency position;
• and
• setting the valves in the first position by supplying electrical power to the valves to counteract the spring force and thereby move the control valves into the first position.

An apparatus for cooling a tool in a heat-treatment furnace, the apparatus comprising:

• a coolant supply having an intake line and an output line;
• a coolant feed and a coolant return connected to the tool;
• control valves connected to the coolant feed and to the coolant return as a normal cooling circuit and an alternate emergency cooling circuit, the control valves
• during a normal cooling operation connecting the coolant feed and the coolant return as the normal cooling circuit in a first position in which a coolant flows through the tool, the feed is connected via the intake line to the coolant supply and the return back to the coolant supply, and the control valves
• in an emergency position during a power failure reset and connect the feed and return of the tool as the emergency cooling circuit in which water is fed through the tool by connection of the feed with a tap of a municipal water system and the return is connected to a municipal sewage system;
• respective sensors on the feed, the return, the coolant intake line, and the coolant outlet line the detect parameters of the coolant therein;
• means for interrupting electrical power supply when actual detected values of the parameters either exceed or fall below predetermined desired levels of the parameters.

An apparatus for cooling a tool in a heat-treatment furnace, the apparatus comprising:

• a coolant supply having an intake line and an output line;
• a coolant feed and a coolant return connected to the tool;
• control valves connected to the coolant feed and to the coolant return as a normal cooling circuit and an alternate emergency cooling circuit, the control valves
• during a normal cooling operation connecting the coolant feed and the coolant return as the normal cooling circuit in a first position in which a coolant flows through the tool, the feed is connected via the intake line to the coolant supply and the return back to the coolant supply, and the control valves
• in an emergency position during a power failure reset and connect the feed and return of the tool as the emergency cooling circuit in which water is fed through the tool by connection of the feed with a tap of a municipal water system and the return is connected to a municipal sewage system;
• a respective spring in each of the control valves that urges the control valves forcibly into the emergency position;
• and
• a power supply electrically urging the valves into the first position with a force that overcomes a spring force of the springs.