Ropes - General Arrangement

SADDLE BLOCK

The saddle block is positioned between the boom side girders in the mid-section of the boom. It pivots on manganese-bronze bushings about the shipper shaft. It acts as a guide for the longitudinal movement of the dipper handle. The free-floating design of the handle in the saddle block eliminates handle torsion.

DIPPER HANDLE

The dipper is attached to one end of the large diameter handle. The crowd rope half-sheave is attached to the other end. A hydraulic rope take-up mechanism at the dipper end, and the crowd rope adjusting mechanism are used to remove slack from the crowd/retract rope system. The dipper handle crowds out and retracts within the saddle block.

An electrical rate reduction circuit, along with the crowd ropes, absorb digging shock loads encountered when the dipper is crowded into the bank.

DIPPER

A general purpose dipper is usually constructed as a casting and plate weldment. The dipper lip and lower front are alloy heat treated castings. The dipper body, back, upper sides and door are made of steel plate. Removable Whistler type tooth adapters and replaceable tooth points are attached to the lip casting to penetrate the bank material.

The door is hinged and latched to the dipper body. A dipper trip mechanism controls the release of the latch bar, allowing the door to swing open. The latch bar holds the door shut during digging. Spring loaded snubbers dampen the door’s swinging action.

Dipper Assembly