Heat seamer

Claim 1

A SEALING MACHINE FOR FORMING A SEAM BETWEEN TWO SHEETS OF THERMOPLASTIC MATERIAL COMPRISING IN COMBINATION A FRAME, A WORK TABLE ON SAID FRAME FOR SUPPORTING SUPERIMPOSED SHEETS TO BE JOINED WITH TWO ADJACENT EDGES IN SUBSTANTIAL ALIGNMENT, CONVEYOR MEANS ASSOCIATED WITH SAID TABLE FOR FEEDING SAID SHEETS LONGITUDINALLY THEREOF, SPACED SUBSTANTIALLY PARALLEL HOLLOW SHAFTS JOURNALED IN SAID FRAME ONE ABOVE THE OTHER, A SEALING ROLL FIXED TO ONE END OF EACH SHAFT ADJACENT AN EDGE OF SAID TABLE, MEANS FOR DRIVING SAID ROLLS COMPRISING A MOTOR AND A VARIABLE SPEED TRANSMISSION, TREADLE MEANS MOUNTED ON SAID FRAME FOR CONTROLLING THE OUTPUT OF SAID STRANSMISSION WHEREBY THE SPEED OF ROTATION OF SAID ROLLS MAY BE INFINITELY VAIRED BETWEEN ZERO AND MAXIMUM, MEANS ON ONE OF SAID ROLLS FOR DRIVING SAID CONVEYOR IN SYNCHRONISM THEREWITH, A HEATING ELEMENT DISPOSED IN EACH ROLL, SLIP RINGS FIXED ON SAID SHAFTS AND BRUSHES IN CONTACT THEREWITH, CONDUCTORS CONNECTED TO SAID HEATING ELEMENTS AND SAID SLIP RINGS AND EXTENDING THROUGH SAID HOLLOW SHAFTS WHEREBY ELECTRICAL ENERGY MAY BE SUPPLIED TO SAID HEATING ELEMENTS, A RELAY CONNECTED IN AN ELECTRICAL SUPPLY CIRCUIT FOR SAID HEATING ELEMENTS, AN ADJUSTABLE THERMOSTAT DISPOSED IN ONE ROLL AND CONNECTED THROUGH SAID SLIP RINGS TO SAID RELAY WHEREBY THE TEMPERATURE OF SAID HEATING ELEMENTS MAY BE CONTROLLED, MEANS FOR ADJUSTING SAID THERMOSTAT, MEANS FOR PERMITTING MOVEMENT OF ONE ROLL AWAY FROM THE OTHER, ADJUSTABLE YIELDABLE MEANS FOR BIASING SAID ROLLS TOWARDS EACH OTHER WHEREBY THE PRESSURE APPLIED TO WORK THEREBETWEEN MAY BE VARIED, MEANS FOR SUPPORTING A SUPPLY OF THERMOPLASTIC BINDING TAPE ON SAID FRAME, TAPE-PULLING MEANS DRIVEN BY SAID SEALING ROLL DRIVE MEANS IN SYNCHRONISM THEREWITH, MEANS FOR RENDERING SAID TAPE-PULLING MEANS OPERATIVE OR INOPERATIVE IN ACCORDANCE WITH THE TENSION IN THE TAPE FED THEREFROM, MEANS FOR APPLYING SOLVENT TO ONE SURFACE OF SAID TAPE, MEANS FOR REMOVING EXCESS SOLVENT FROM SAID TAPE, MEANS FOR LONGITUDINALLY FOLDING SAID TAPE UPON ITSELF AND APPLYING THE SAME OVER THE EDGES OF SAID SHEETS TO BE JOINED WHEREBY UPON PASSING BETWEEN SAID SEALING ROLLS SAID SHEETS WILL BE JOINED TO SAID BINDING TAPE UNDER THE ACTION OF HEAT AND PRESSURE TO FORM A CONTINUOUS SHEET.