Patent ID: 6336405
Filing Date: 2002-01-08
Classification: B41F,B41P,F04B

Abstract:
A pump for a printing machine for sucking and discharging ink by repeatedly reciprocating a plunger operated by a motor once while the plunger is rotated once within a main hole of a cylinder, the pump comprising:a base; the cylinder which is attached to the base and has the main hole closed on one side thereof and also has a suction hole and a discharge hole opened in positions different from each other in phase on an inner circumferential face of the main hole; the plunger which is fitted onto an opening side of the main hole of the cylinder so as to be axially moved and rotated from an end tip of the main hole and simultaneously close the suction hole and the discharge hole of the cylinder in a certain rotating phase and also close one of the suction hole and the discharge hole in a different rotating phase; the motor attached to the base such that a rotating central line of a rotating shaft crosses that of the plunger at a predetermined crossing angle; a transmission mechanism which is constructed by an arm fixed to the output shaft of the motor and approximately projected in parallel with the rotating central line of the output shaft of the motor, and is also constructed by a connection member slidably attached to an inner ring hole of a spherical bearing fixed to the arm and fixed to a rear end side of the plunger and connecting the arm and the plunger to each other; and retrogression preventing means for arranging the plunger temporarily stopped at a discharging stroke during an operation of the pump intermittently operated by the motor such that the plunger is not retreated and not angularly displaced in a direction reverse to a predetermined operating direction.