1188 THE COLLIERY GUARDIAN, June 6, 1913. machine of this class it will do more rapid work than any other class of machine with less labour. It is of a very compact design, being designed to suit thin seams and to occupy the minimum of width. The general arrangement is such as to facilitate working beneath low roofs, all parts being very accessible. The under part of the machine is designed to serve as skids, and the machine is designed to cut close to the floor when arranged for undercutting. Chain Machine. (Anderson, Boyes & Co. Limited.) 16J in. Disc Coalcutter Driven by D.C. Motor. (Anderson, Boyes & Co. Limited.) r “ THE COVENTRY ” CHAIN CO. LIMITED. This firm’s exhibits comprise samples of noiseless and roller chains used for power transmission on colliery, machinery, factory and mill drives; triple speed reduction box, stationary; 50 horse-power chain drive reduction gear, from 620 to 690 transmitting power through “ Coventry ” noiseless chains; and a colliery haulage gear coupled to “Coventry” noiseless chain- driven reduction gear box in motion. allows a rapid motion from step to step, but ensures a definite stop on the centre of each ; shunt regulator with electrical interlock to ensure full field on the motor when starting. There is also shown a solenoid-operated starter, as used for automatic or remote control of pumps, air - compressors, &c., an interesting electrical feature of which is that the main switch and the resistance controlling lever are operated by separate iron cones moving one at each end of a single solenoid coil. Suitable for alternating current is a pillar, comprising cast iron pedestal, carrying ammeter, fuse box and oil- immersed transformer starter, the whole forming a self- contained unit. Special glass windows have been fitted A.C. Combined Ammeter, Fuse Box, and Transformer Starter. (Electrical Apparatus Company Limited.) 20J in. Disc Coalcutter Driven by A.C. Motor. (Anderson, Boyes & Co. Limited.) The motors are of very robust construction, the •design being specially adapted to withstand the severe conditions under which these machines operate. The starters are of the drum type and are insulated solely with mica, which experience has proved to be the most suitable material for such purposes. The trailing cable plug is of the all-metal type and is designed to provide reliable means for efficiently earthing the machine. The gear case is of cast steel of substantial design, arranged with covers for withdrawal and inspection of the gear. It is designed to be dustproof. The chain is of mild steel machined from the solid bar and case- hardened, the pick holders being formed separately and so designed as to facilitate the ready removal of the picks, which are of simple form. The jib is of very strong construction of cast steel, provided with steel guides for the chain, and at the end with a specially designed roller and ball bearing for the return sprocket to run on. The haulage gear is driven from the end of the armature shaft through worm-reducing gear. The worm is of mild steel cut from the solid, and gears with a hobbed worm wheel of phosphor bronze. This gear is contained in a steel casing designed to form an oil bath. The distribution boxes and gate-end boxes supplied by the firm are of the treble-pole, double-pole, and single- pole type. The gate-end boxes consist of cast iron cases with hinged lids, the switch and fuses being con- tained in separate compartments, having a separate lid to each compartment. The switches of the quick-break type are operated by means of an external handle. The switch contacts are of the block pattern and are, in common with the switch blades, mounted on mica- insulated steel bars. The fuse handles are of porcelain, having block contacts. The fuse contacts are also mounted on mica-insulated steel bars. The gate-end box is provided at one end with a plug box, having the terminals insulated by means of mica. The plug is of aluminium, having the terminals also insulated solely by mica. Each compartment of the box is provided with interlocking gear, so arranged in conjunction with the switch handle that it is impossible to open either lid until the switch is in the “ off ” position, or to switch on while either of the lids is open. The plug is also interlocked so that it can be neither inserted nor with- drawn with the switch in the “ on ” position. These boxes are fitted when required with bifurcating or trifurcating boxes for use with armoured cable, so designed as to • effectually earth the box to the armouring. direct-current gear is represented by a panel comprising the following units, all totally enclosed, the necessary interconnection being run in screwed conduit :—D.P. switch fuse (metal and mica construction) ; starter fitted with the E.A.C. patent slow motion device which Automatic D.C. Starter. (Electrical Apparatus Company Limited.) ijn X ■‘.I’’- ELECTRICAL APPARATUS CO. LIMITED. The Electrical Apparatus Company Limited, of Vauxhall Works, South Lambeth-road, London, S.W., are makers of electric control gear, switches and starters for all duties', and show on their stand a few of their types specially suited for use in mines. The One Mincte Slow-Motion Starter. (Electrical Apparatus Company Limited.) ,©) ■ '■ •I ■ ■0 © ■ to the tank of the starter enabling the interior to be seen—especially the switch, which is of drum type—all live parts being clamped on to mica insulated steel bars. An automatic triple-pole oil switch on the same principle is also shown, this being fitted with the E.A.C. patent oil level interlock which prevents the switch from being closed if for any reason insufficient oil is present to cover the contacts. Samples are shown of resistance elements and other minor parts used for various purposes, including some specimens of the E.A.C. controller finger. This can be fitted to any of the firm’s alternating current gear, and has all the good points of the best designed fingers, such as coil compression springs, screw and nut adjustment, automatic self-alignment, ready renewal, mica insulation. The integrating meters, both D.C. and A.C.—for which the Electrical Apparatus Company Limited are so well known in electrical distribution circles— are represented by typical sizes, and a number of photographs show complete mining switchboards, and many other E.A.C. manufactures which cannot be shown in the limited space available at an exhibition. THE GOSFORTH FOUNDRY COMPANY LIMITED. Messrs, the Gosforth Foundry Company Limited (Dronfield), show various types of driving and elevating chains (Ewart’s and Gray’s styles), sprocket wheels, &c.