Undercarriage for a telescopic frame

Abstract

A telescopic undercarriage for raising and lowering a frame. The undercarriage includes a base section having a pair of parallel base legs extending from a first end to a second end of the base section, the base section including a first plurality of braces extending between respective upper surfaces of the base legs and a second plurality of braces extending between respective lower surfaces of the base legs, the base legs, first plurality of braces and second plurality of braces collectively providing an elongate central base section passage. The undercarriage also includes an extendable section slidably disposed within the base section passage and having opposed legs, a drive system for extending and retracting the extendable section relative to the base section.

1 . In a telescopic undercarriage for raising and lowering a frame, the improvement comprising:
 an extendable section telescopically mounted within a base section passage for movement from the base section between retracted and extended positions, and having opposed base legs, each base leg defining an elongate open-sided base leg channel facing the other base leg;   a hydraulic drive system connected to the base section and the extendable section for extending the extendable section from the second end of the base section, the hydraulic drive system including a first hydraulic drive cylinder driving a first piston and a second spaced-apart hydraulic drive cylinder driving a second piston, each of the first and second hydraulic drive cylinders being mounted solely within one of the base leg channels; and   the hydraulic drive cylinder being mounted within the other of the base leg channels and the first and second pistons mounted within the other of the extendable section legs such that when the extendable section is extended, the pistons and drive cylinder serve as reinforcement.   
     
     
         2 . The undercarriage according to  claim 1 , wherein the extendable section is retractable within the base section to a transport position and extended to a plurality of use positions, the undercarriage including a releasable mechanical stopper mounted to the base section and having a contact portion for engaging the extendable section to prevent retraction of the extendable section fully to the transport position. 
     
     
         3 . The undercarriage according to  claim 1 , in combination with a radial stacker wherein a first end of the base section is connected to a base support frame of the radial stacker and an extendable end of the extendable section is connected to a telescopic conveyor belt for raising and lowering the telescopic conveyor belt. 
     
     
         4 . The undercarriage according to  claim 1 , wherein the base legs each have a U-shaped cross-section. 
     
     
         5 . The undercarriage according to  claim 1 , wherein the hydraulic drive system includes a first hydraulic cylinder driving a first piston and a second hydraulic cylinder driving a second piston, the first hydraulic drive cylinder being mounted within one of the base leg channels and the first piston being mounted within one of the extendable section legs, the second hydraulic cylinder being mounted within the other of the base leg channels and the second piston being mounted within the other of the extendable section legs the pistons and their mountings serving to reinforce the extendable legs. 
     
     
         6 . The undercarriage according to  claim 5 , wherein the extendable section can be retracted within the base section passage to a transport position and extended to a plurality of use positions, the undercarriage including a releasable mechanical stopper mounted to the base section and having a contact portion for engaging the extendable section to prevent retraction of the extendable section fully to the transport position. 
     
     
         7 . The undercarriage of  claim 5 , wherein the telescopic undercarriage supports a conveyor belt system for moving aggregate.