| 摘要 |
A baler for making parallelepiped bales is equipped with a bale ejector or thrower structure including a bale throwing pan supported by a four-bar linkage that is swung upwardly by a hydraulic throwing cylinder. A control valve structure including a solenoid-operated trip valve and a solenoid-operated pressure-relief valve is actuated for effecting pressurization of the throwing cylinder and throwing of a bale in response to a trip switch being closed in response to a trip pedal being rotated by a bale moving rearwardly on the throwing pan as it exits the baler bale chamber, the trip valve when actuated blocking a source of fluid pressure from normal communication with a fluid sump, and the pressure-relief valve when actuated being operable for maintaining the working fluid pressure at a value determined by a variable potentiometer connected in circuit with the solenoid of the pressure relief valve. The pressure of the fluid available for operating the throwing cylinder and, hence, the distance through which a given bale will be thrown, depends on the setting of the relief valve achieved through adjustment of the variable potentiometer. An interlock circuit is provided for preventing actuation of the throwing cylinder in the event that a shield structure, which surrounds the area occupied by the throwing pan, is lifted to an inoperative position, such lifting opening an interlock switch. An interlock relay switch is provided which, when energized, maintains the availability of power to a power port of a timer coupled for receiving a control signal when the trip switch is tripped, the signal acting to change the state of the timer so that it connects power to the trip and pressure-relief valve solenoids for a preset time, the interlock relay switch acting to open the current path to the timer power input port in response to the interlock switch moving to its normally open position in response to the shield structure being raised to a non-working position.
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