CONTROL CONSOLE

Controls on the drill guide are only for drilling and _{cylinder movement.} All other engine controls, tramming valve, and cylinder valve are located around the operator's seat, as shown in figure 14-22.

BOOM

The rock drill is equipped with an expendable boom, commonly called a mast. The boom can vary 5 feet in length from the fully retracted to the fully extended

position. The extendable booms are constructed of square steel tubing with a dump base holder at the front end and a clevis at the rear end. The clevis is hinged to a pedestal that is held in the boom base clevis by a kingpin.

Figure 14-22.-Operator's control console.

The pedestal is free to rotate in the boom base clevis, and the boom is free to swing up and down in the pedestal; for example, the assembly is a universal joint that permits the boom to be swung from side to side or raised and lowered. A clevis, welded to the bottom side of the boom tube, supports the piston end of the lift cylinder, and a clevis, welded to the right side of the boom tube, supports the piston end of the swing cylinder.

DUMP AND SWING ASSEMBLY

The hydraulically powered dump and swing assembly is used to support and position the drill guide. The assembly permits 180-degree drill guide dump and 90-degree drill guide swing.

GUIDE SWING AND EXTENSION MOUNTING

The hydraulically powered guide extension assembly extends the drill guide for additional coverage or places the drill guide foot piece firmly against the ground for additional stability.

DRILL MOUNTING

The drill mounting consists of the drill guide, drill mounting plate, centralizer/foot piece, feed chain, feed motor assembly, and hose reel plate.

Drill Guide

The upper end of the guide is fitted with a hydraulic feed motor. A combination centralizer/foot piece is bolted to the lower end of the drill guide.

Drill Mounting Plate

The drill is mounted on a drill mounting plate that is clamped to and travels on the drill guide with the aid of four roller bearings.

Feed Chain

The drill guide is fitted with a heavy-duty roller chain for the drill mounting plate. The chain passes over a sprocket on the lower end of the guide and a drive sprocket in the feed motor on the upper end of the guide. The chain has two chain joints at both ends, connected at the bottom of the mounting plate with a link joint.

Feed Motor Assembly

The hydraulically powered feed motor assembly, which incorporates a planetary gear drive unit, is bolted at the upper end of the drill guide. A brake valve is installed in the hydraulic circuit just before the hydraulic feed motor. The brake valve absorbs the shock when the hydraulic feed motor receives a shock load and prevents spontaneous dropping of the drill. The feed motor feeds the drill through the feed chain and drill mounting plate up and down the drill guide. The feed motor is capable of exerting a maximum pull up of 4,410 pounds.

Hose Reel Plate

All the hoses for the drill are connected by way of the hose reel to the hose holder, which is attached to the right medium part of the drill guide.