Control device for signalling a predetermined time period of flow of current between two terminals

Claim 1

A CONTROL DEVICE FOR SIGNALLING THE EXPIRATION OF A TIME INTERVAL BETWEEN NECESSARY SERVICING OF A MACHINE SUCH AS MOTOR VEHICLE OR THE LIKE COMPRISING, IN COMBINATION, ELONGATED SUPPORT MEANS OF INSULATING MATERIAL; A PAIR OF RESILIENT CONTACT MEANS MOUNTED SPACED FROM EACH OTHER ON SAID SUPPORT MEANS; AN INDICATOR TUBE OF TRANSPARENT MATERIAL AND HAVING OPPOSITE OPEN ENDS; A PAIR OF INSULATING PLUGS IN SAID OPEN ENDS FOR CLOSING THE SAME; A METAL CAPSULE EXTENDING THROUGH AN OPENING IN ONE OF THE PLUGS AND HAVING A BOTTOM PORTION LOCATED IN THE SPACE BETWEEN SAID PLUGS; A LIQUID COLORING MATERIAL IN SAID CAPSULE; AN ELECTROLYTE FILLING THE SPACE BETWEEN SAID PLUGS; AN ELECTRIC CONTACT EXTENDING THROUGH THE OTHER PLUG, SAID RESILIENT CONTACT MEANS RESPECTIVELY ENGAGING AN OUTER END OF SAID METAL CAPSULE AND AN OUTER END OF SAID ELECTRICAL CONTACT FOR REMOVABLY HOLDING SAID INDICATOR TUBE ON SAID SUPPORT MEANS; AND AN ELECTRIC CIRCUIT ADAPTED TO BE CONNECTED TO SAID MACHINE AND TO BE ENERGIZED WHENEVER THE MACHINE IS IN OPERATION AND ONE TERMINAL OF THE CIRCUIT CONNECTED THROUGH ONE RESILIENT CONTACT MEANS TO SAID CAPSULE AND THE OTHER TERMINAL THROUGH THE OTHER RESILIENT CONTACT MEANS TO SAID ELECTRIC CONTACT IN SUCH A MANNER THAT THE CAPSULE FORMS THE ANODE OF THE ELECTROLYTIC CIRCUIT FORMED BETWEEN SAID CAPSULE AND SAID ELECTRIC CONTACT, WHEREBY AS CURRENT FLOWS THROUGH SAID ELECTRIC CIRCUIT THE BOTTOM PORTION OF SAID CAPSULE WILL BE GRADUALLY ELECTROLYTICALLY DISSOLVED SO THAT AFTER AN OPENING IS THUS FORMED AFTER A PREDETERMINED TIME OF CURRENT FLOW THROUGH THE CONTROL DEVICE THE COLORING MATERIAL IN SAID CAPSULE WILL MIX WITH THE ELECTROLYTE TO GIVE THEREBY AN OPTICAL SIGNAL TO THE OPERATOR OF THE MACHINE INDICATING THE EXPIRATION OF THE TIME INTERVAL BETWEEN NECESSARY SERVICING OF THE MACHINE.