Method and system for preventing containerless discharging of filling material in container filling apparatus

Claim 2

In a method of filling successively a prescribed quantity of a fluid material into respective containers by means of a plurality of charging cylinders arranged in a circle around a vertical main shaft to revolve therearound and having respective pistons while precluding discharge of the fluid material in the absence of a container to be filled, each of the cylinders being adapted to introduce thereinto the fluid material from a header chamber during the intake stroke of the piston thereof and then to discharge its filled material into a corresponding container during the discharge stroke of the piston, passageways of the introduction and discharge of the fluid material being established through a switching valve member, and switching of the valve member and reciprocal stroke of the cylinder piston being caused in relation to the revolution of the charging cylinders, an improvement in the preclusion process for discharge of the fluid material in the absence of a container to be filled comprising when the absence of a container at a filling position on a container platform is detected, the piston of the charging cylinder corresponding to the filling position is locked in response to the detection against the intake stroke thereof prior to the intake stroke and the locking is released after the piston and its cylinder have revolved past the filling position in order to prevent containerless discharging of the fluid material.

Claim 3

In a container filling apparatus of rotary type comprising a plurality of fluid material charging cylinders arranged in a circle around a vertical main shaft to revolve thereabout and having respective pistons, a plurality of containers preparatorily provided on respective container platforms which are successively revolved into a filling position in relation to revolution of the charging cylinders, each of the charging cylinders being adapted to introduce a fluid material thereinto from a material header chamber during the intake stroke of the piston thereof and subsequently to discharge its filled material into the corresponding container at its filling position on the container platform during the discharge stroke of the piston, a switching valve member for establishing passageways for the introduction and discharge of the fluid material, switching of the valve member and a reciprocal stroke of the cylinder piston being effected with respect to revolution of the charging cylinders, and a precluding means adapted to preclude containerless charging of the fluid material when the absence of a container at a filling position is detected, and improvement of the precluding means, the precluding means comprising: detecting means adpated to detect the absence of a container at the filling position and to produce a command signal when absence is detected; locking means including a locking device provided revolvably together with a respective charging cylinder, the locking device being adapted to be actuated to lock the piston rod of the respective charging cylinder at a position where the piston rod is at the start of its intake stroke; and actuating means adapted to be operated by the command signal of the detecting means to actuate the locking device corresponding to a specific filling position on the container platform having no container mounted thereon causing locking of the piston rod of the charging cylinder corresponding to the filling position against the intake stroke thereof prior to the intake stroke; and unlocking means adapted for unlocking the locking device after the piston rod and the corresponding charging cylinder have revolved past the filling position in order to preclude containerless discharge of the filling material.

Claim 4

In a container filling apparatus of rotary type comprising a plurality of fluid material charging cylinders arranged in a circle around a vertical main shaft to revolve thereabout and having respective pistons, a plurality of containers preparatorily provided on respective container platforms which are successively revolved into a filling position in relation to revolution of the charging cylinders, each of the charging cylinders being adapted to introduce a fluid material thereinto from a material header chamber during the intake stroke of the piston thereof and subsequently to discharge its filled material into the corresponding container at its filling position on the container platform during the discharge stroke of the piston, a switching valve member for establishing passageways for the introduction and discharge of the fluid material, switching of the valve member and a reciprocal stroke of the cylinder piston being effected with respect to revolution of the charging cylinders, and a precluding means adapted to preclude containerless charging of the fluid material when the absence of a container at a filling position is detected, and improvement of the precluding means, the precluding means comprising: detecting means adpated to detect the absence of a container at the filling position and to produce a command signal when absence is detected; locking means including a locking device provided revolvably together with a respective charging cylinder, the locking device being adapted to be actuated to lock the piston rod of the respective charging cylinder at a position where the piston rod is at the start of its intake stroke; and actuating means adapted to be operated by the command signal of the detecting means to actuate the locking device corresponding to a specific filling position on the container platform having no container mounted thereon causing locking of the piston rod of the charging cylinder corresponding to the filling position against the intake stroke thereof prior to the intake stroke; and unlocking means adapted for unlocking the locking device after the piston rod and the corresponding charging cylinder have revolved past the filling position in order to preclude containerless discharge of the filling material.

Claim 5

A container filling apparatus as claimed in claim 2 wherein the locking device comprises an engaging member having an engaging part engageable with and disengageable from a stepped part formed in the piston rod in order to lock and unlock the piston rod, a thrust bar coupled at one end thereof to the engaging member and adapted to undergo locking and unlocking strokes respectively to move the engaging part into and out of engagement with the stepped part, a spring for continuously urging the thrust bar in the direction for locking the piston rod, and a catch lever engageable with an engagement shoulder of the thrust bar to lock the bar at the end of the unlocking stroke by the force of a spring in a normal state; the actuating means comprising an actuating device operated by a command signal from the detecting means to disengage the catch lever from the engagement shoulder of the thrust bar corresponding to the platform having no container mounted thereon in order to permit the thrust bar to move during the locking stroke under the force of the spring; and the unlocking means comprising a cam member stationarily disposed in a position to be contacted at its cam surface by the other end of the thrust bar undergoing revolution in order to force the thrust bar during the unlocking stroke against the force of the spring until the catch lever engages with the engagement shoulder thereof.

Claim 6

A container filling apparatus as claimed in claim 2, wherein the locking means comprises a thrust bar provided for each piston rod of each charging cylinder and having at one end thereof an engagement slot engageable with and disengageable from a stepped part formed in the piston rod in order to lock or unlock the piston rod, the one end of the thrust bar constituting the locking part and the thrust bar being adapted to undergo locking and unlocking strokes respectively to place the engagement slot into and out of engagement with the stepped part, a spring to continuously urge the thrust bar in the direction of the unlocking stroke in order to normally position the thrust bar at the end of the unlocking stroke, a catch lever having a release arm and a catch arm engageable with an engagement shoulder of the thrust bar to lock the thrust bar at the end of the locking stroke, and a spring for urging the catch lever to the position engageable with the engagement shoulder; the actuating means comprising an actuating device operated by the command signal from the detecting means and adapted to push the thrust bar when the device is operated toward the piston rod against the force of the spring in order to cause engagement of the engagement slot with the stepped part of the piston rod and to cause movement of the catch arm to the position adaptable to be engaged with the engagement shoulder of the thrust bar; and the unlocking means comprising a resetting cam stationarily disposed in a position to be contacted at its cam surface by the revolving catch lever of the thrust bar in order to push the release arm and to cause disengagement of the catch arm from the engagement shoulder against the force of the spring to cause the unlocking stroke of the thrust bar by the spring.

Claim 7

A system as claimed in claim 2 in which the actuating means is an air cylinder-and-piston actuator operated by air supplied from a pneumatic power supply operated in accordance with said detection signal.

Claim 8

A system as claimed in claim 2 in which the actuating means is an electromagnetic actuator operated by electrical power from an electric power supply operated in accordance with said detection signal.

Claim 9

A system as claimed in claim 2 in which the actuating means is a hydraulic cylinder-and-piston actuator operated by hydraulic fluid supplied from a hydraulic power supply operated in accordance with said detection signal.