Patent ID: 7802956

Claim:
An apparatus for automatically unloading material from an elongate storage bag, the apparatus comprising: a frame assembly; a collection mechanism configured to remove the material from the storage bag; a drive mechanism capable of advancing the apparatus along the direction of the storage bag; and a sensor arrangement configured to engage the storage bag and to automatically control the drive mechanism according to pressure exerted on the sensor arrangement because of the presence of material within the storage bag, wherein the sensor arrangement comprises: an actuator member that is spring-biased; a hydraulic switch that actuates the drive mechanism and is operatively manipulated by the actuator member; wherein pressure exerted on the actuator member, as the apparatus advances in the direction of the storage bag, causes the actuator member to move against its bias which, in turn, causes the switch to deactivate the drive mechanism and stop advancement of the apparatus; and wherein spring-driven return movement of the actuator member causes the switch to activate the drive mechanism and resume advancement of the apparatus along the direction of the storage bag.