Constant-temperature bath

Claim 1

APPARATUS FOR MAINTAINING THE TEMPERATURE OF A BATH, COMPRISING A TEMPERATURE-RESPONSIVE ELEMENT ADAPTED TO BE IMMERSED IN A BATH AND TO GENERATE A SIGNAL WHICH IS A FUNCTION OF ITS OWN TEMPERATURE, HEATING MEANS TO SUPPLY HEAT TO THE BATH, CONTROL MEANS RESPONSIVE TO THE SIGNAL FROM SAID TEMPERATURE-RESPONSIVE ELEMENT TO INCREASE THE RATE AT WHICH HEAT IS SUPPLIED TO SAID BATH BY SAID HEATING MEANS WHEN THE SIGNAL INDICATES SAID ELEMENT HAS COOLED BELOW A FIRST PREDETERMINED TEMPERATURE AND TO DECREASE THE RATE AT WHICH HEAT IS SUPPLIED TO SAID BATH BY SAID HEATING MEANS WHEN THE SIGNAL INDICATES SAID ELEMENT HAS BEEN HEATED TO A SECOND PREDETERMINED TEMPERATURE, A RADIANT ENERGY SOURCE ADAPTED TO BE IMMERSED IN SAID BATH AND RESPONSIVE TO THE SIGNAL FROM SAID TEMPERATURE-RESPONSIVE ELEMENT TO HEAT SAID ELEMENT A SUBSTANTIALLY FIXED TEMPERATURE DIFFERENTIAL ABOVE THE SURROUNDING BATH MEDIUM AFTER THE RATE AT WHICH HEAT IS BEING SUPPLIED BY SAID HEATING MEANS IS INCREASED AND BEFORE SAID RATE IS DECREASED, WHEREBY THE RATE AT WHICH HEAT IS SUPPLIED BY THE HEATING MEANS IS DECREASED BEFORE THE BATH MEDIUM REACHES SAID SECOND PREDETERMINED TEMPERATURE, LIQUID-TIGHT MEANS SURROUNDING SAID RADIANT ENERGY SOURCE AND SPACED THEREFROM BY A CONFINED SPACE TO THERMALLY INSULATE SAID RADIANT ENERGY SOURCE FROM CONDUCTIVE HEAT TRANSFER WITH SAID BATH, SAID LIQUID-TIGHT MEANS BEING TRANSPARENT IN AT LEAST A PORTION THEREOF THAT FACES SAID TEMPERATURE-RESPONSIVE ELEMENT, AND REFLECTOR MEANS SURROUNDING SAID RADIANT ENERGY SOURCE AND POSITIONED BETWEEN SAID RADIANT ENERGY SOURCE AND SAID LIQUID-TIGHT MEANS AND ADAPTED TO FOCUS A MAJOR PORTION OF THE RADIATION FROM SAID SOURCE THROUGH A TRANSPARENT PORTION OF SAID LIQUID-TIGHT MEANS ONTO SAID TEMPERATURE-RESPONSIVE ELEMENT.