Hot melt nozzle with reciprocating piston drip-prevention means

Claim 2

A NOZZLE FOR DEPOSITING HOT MELT COMPRISING: A BODY INCLUDING AN INLET THEREIN FOR RECEIVING HOT MELT UNDER PRESSURE AND A BORE IN COMMUNICATION WITH SAID INLET; A MEANS FOR REMOVING IMPURITIES FROM SAID HOT MELT INTERPOSED BETWEEN SAID INLET AND SAID BORE; A PISTON HAVING AN EXTERIOR SURFACE ADAPTED TO SLIDE WITHIN SAID BORE, A LONGITUDINAL PASSAGE CLOSED AT BOTH ENDS THEREOF, AND TWO TRANSVERSE PASSAGES, AN UPPER AND A LOWER EACH COMMUNNICATING SAID LONGITUDINAL PASSAGE WITH THE EXTERIOR SURFACE OF SAID PISTON; A DISPENSING MEMBER SECURED TO SAID BODY BELOW SAID BORE AND INCLUDING A CHAMBER OF A GREATER DIAMETER THAN SAID BORE; DRIVING MEANS SECURED TO SAID PISTON FOR SELECTIVELY RECIPROCATING SAID PISTON SO THAT SAID PISTON IN ITS BOTTOMMOST POSITION IS DISPOSED WITH SAID UPPER TRANSVERSE PISTON PASSAGE OF SAID PISTON IN COMMUNICATION WITH SAID HOT MELT INLET AND SAID LOWER TRANSVERSE PISTON PASSAGE IN COMMUNICATION WITH SAID CHAMBER OF SAID DISPENSING MEMBERS AND SAID TRANSVERSE PISTON PASSAGES BEING OUT OF COMMUNICATION WITH SAID INLET AND CHAMBER WHEN SAID PISTON IS AT ITS UPPERMOST POSITION.

Claim 3

A NOZZLE FOR DEPOSITING HOT MELT COMPRISING: A BODY INCLUDING AN INLET FOR RECEIVING A VISCOUS LIQUID UNDER PRESSURE, SAID BODY HAVING A BORE IN COMMUNICATION WITH SAID INLET, PISTON MEANS HAVING AN EXTERIOR SURFACE ADAPTED TO SLIDE WITHIN SAID BORE, SAID PISTON INCLUDING A LONGITUDINAL PASSAGE CLOSED AT BOTH ENDS THEREOF, AND A FIRST TRANSVERSE PASSAGE MEANS AND A SECOND TRANSVERSE PASSAGE MEANS EACH COMMUNICATING SAID LONGITUDINAL PASSAGE WITH THE EXTERIOR SURFACE OF THE PISTON MEANS, A DISPENSING MEMBER SECURED TO SAID BODY IN ALIGNMENT WITH ONE END OF SAID BORE, SAID DISPENSING MEMBER HAVING A CHAMBER OF A GREATER DIAMETER THAN SAID BORE, DRIVING MEANS SECURED TO SAID PISTON FOR SELECTIVELY RECIPROCATING SAID PISTON IN SAID BORE TO A FIRST POSITION AND A SECOND POSITION, SAID PISTON BEING IN THE FIRST POSITION WHEN SAID FIRST TRANSVERSE PASSAGE IS IN COMMUNICATION WITH SAID INLET AND SAID SECOND TRANSVERSE PASSAGE IS IN COMMUNICATION WITH SAID CHAMBER WHEREBY THE VISCOUS LIQUID UNDER PRESSURE FLOWS THROUGH SAID PISTON AND DISPENSING MEMBER TO A DISCHARGE LOCATION, AND SAID PISTON BEING IN THE SECOND POSITION WHEN THE FIRST AND SECOND PASSAGE MEANS ARE OUT OF COMMUNICATION WITH SAID INLET AND SAID CHAMBER RESPECTIVELY.

Claim 4

A NOZZLE FOR DEPOSITING HOT MELT COMPRISING: A BODY INCLUDING AN INLET FOR RECEIVING A VISCOUS LIQUID UNDER PRESSURE, SAID BODY HAVING A BORE IN COMMUNICATION WITH SAID INLET, PISTON MEANS HAVING AN EXTERIOR SURFACE ADAPTED TO SLIDE WITHIN SAID BORE, SAID PISTON INCLUDING A LONGITUDINAL PASSAGE CLOSED AT BOTH ENDS THEREOF, AND A FIRST TRANSVERSE PASSAGE MEANS AND A SECOND TRANSVERSE PASSAGE MEANS EACH COMMUNICATING SAID LONGITUDINAL PASSAGE WITH THE EXTERIOR SURFACE OF THE PISTON MEANS, A DISPENSING MEMBER SECURED TO SAID BODY IN ALIGNMENT WITH ONE END OF SAID BORE, SAID DISPENSING MEMBER HAVING A CHAMBER OF A GREATER DIAMETER THAN SAID BORE, DRIVING MEANS SECURED TO SAID PISTON FOR SELECTIVELY RECIPROCATING SAID PISTON IN SAID BORE TO A FIRST POSITION AND A SECOND POSITION, SAID PISTON BEING IN THE FIRST POSITION WHEN SAID FIRST TRANSVERSE PASSAGE IS IN COMMUNICATION WITH SAID INLET AND SAID SECOND TRANSVERSE PASSAGE IS IN COMMUNICATION WITH SAID CHAMBER WHEREBY THE VISCOUS LIQUID UNDER PRESSURE FLOWS THROUGH SAID PISTON AND DISPENSING MEMBER TO A DISCHARGE LOCATION, AND SAID PISTON BEING IN THE SECOND POSITION WHEN THE FIRST AND SECOND PASSAGE MEANS ARE OUT OF COMMUNICATION WITH SAID INLET AND SAID CHAMBER RESPECTIVELY.