Carton sealing machine with safety stop of the conveying belts at the end of the operation

A carton sealing machine for sealing cartons, comprising:

• a support base for the cartons;
• a movable sealing head movable relative to said base and positionable at variable heights above said base to define with said base a carton sealing area;
• driving means for lifting said movable sealing head from a lowered rest position;
• conveyor means arranged at opposite sides of said base and movable in a direction towards each other to approach each other from a removed rest position to a carton engaged position, said conveyor means in said rest position being disengaged from opposite sides of the carton and in said engaged position being engaged with opposite sides of the carton for the advancement thereof along a path on said base through said sealing area;
• a driving mechanism for said conveyor means;
• motion transmission means including a clutch for transmitting the motion from said driving mechanism to said conveyor means in an engaged condition of said clutch and to disconnect said driving mechanism from said conveyor means in a disengaged condition of said clutch;
• and
• a plurality of sensing means successively arranged along said sealing area to sense the position of an advancing carton advancing through said sealing area, said sensing means including a first sensor positioned at the inlet of said sealing area to cause a lifting of said sealing head from said lowered rest position, a second sensor slightly advanced along the path in said sealing area with respect to said first sensor to cause said conveyor means to move to approach each other to reach said engaged position from said removed rest position, and a third sensor positioned at the outlet of the sealing area to move said conveyor means away from the sides of an engaged carton to return said conveyor means to said removed rest position, and said third sensor being operatively connected to said clutch to cause the disconnection of said driving mechanism from said conveyor means for the subsequent stopping thereof.