The unloader of claim 3 including: plate means connected to the outer end section of the frame means, said upright means being attached to the plate means, said force transmitting means comprising a cable, and pulley means mounted on the plate means accommodating the cable.Ħ. The unloader of claim 3 including: arm means connected to the outer end portion of the rigid member, said force transmitting means being attached to the arm means.ĥ. The unloader of claim 2 wherein: the means mounted on the outer end section of the frame means includes upright means having laterally spaced portions providing an upright slot, said outer end portion of the rigid member extended through said slot and engageable with at least one spaced portion of the upright means.Ĥ. The unloader of claim 1 wherein: the support means is an elongated rigid member located above and extended generally parallel to the collector means, means pivotally connecting the rigid member to the impeller means, said member having an outer end portion engageable with the means mounted on the outer end section of the frame means whereby said drive wheel means operate to move the collector means around the silo.ģ. A top unloading silo unloader for removing material from a tower silo having a cylindrical wall and an open doorway in said wall comprising: frame means having an inner end section locatable in the central section of the silo and an outer end section locatable adjacent the wall, impeller means mounted on the inner end section operable to move material toward an open doorway in the silo wall, collector means extended from the impeller means to the outer end section of the frame means operable to move material to the impeller means, support means connected to the impeller means and extended from the impeller means adjacent the collector means, means mounted on the outer end section of the frame means engageable with the support means to allow the collector means to move up and down relative to the support means, walker beam means rotatably mounted on the support means, said walker beam means having a first end located adjacent one side of the collector means and a second end located adjacent the other side of the collector means, drive wheel means rotatably mounted on the first and second ends of the walker beam means engageable with the material, drive means for rotating the drive wheel means to move the collector means around the silo about a generally upright axis, force transmitting means connected to the support means and movably connected to an outer end section of the collector means, extendible and contractible means mounted on the inner end section of the frame means having a movable member secured to the force transmitting means to hold the force transmitting means in tension whereby the outer end section of the collector means is supported by the drive wheel means, and control means for operating the extendible and contractible means in a manner to maintain the collector means in a desired position.Ģ. The embodiments of the invention in which anĮxclusive property or privilege is claimed are defined as follows:ġ. A reference arm attached to the rotating part of the unloader is linked to the controller so that movement of the collector up or down actuates the controller, whereby the motor operates the linear actuator to reduce its overall length to raise the outer end of the collector or to increase its overall length to lower the outer end of the collector thereby maintaining the outer end of the collector at a selected position. The linear actuator has a reversible electric motor coupled to a motor controller. A cable connects the linear actuator with the outer end of the collector and the support in a manner so that the outer end of the collector can be raised or lowered and held in a selected position in response to operation of the actuator. A collector leveling apparatus has a linear actuator connected to the unloader frame.

Power is applied to both wheels by separate drive shafts connected to a gear box. The support is connected to the impeller housing. The drive wheels are mounted on opposite ends of a rocker arm rotatably supported on a support. An impeller receives material from the collector and throws the material into an out chute which directs the material to a doorway leading to an upright passageway. The unloader has a material collector moved around the silo with leading and trailing drive wheels. A top unloading silo unloader pendently supported in a tower silo.

Silo unloader 240 volt plug