June 6, 1913. THE COLLIERY GUARDIAN. 119/ Ingersoll electric air drills can be adapted as coal- cutters. This drill is driven by pulsations of compressed air created by a pulsator actuated in turn by a standard electric motor, the air being used over and over again. A compensating valve on the pulsator is adjusted auto- matically to maintain the requisite pressure. The “ electric air ” drill can be used with direct or alter- nating current at various voltages, but, generally speaking, 220 volts is a satisfactory pressure. The “Air Radialaxe” coal-cutter is a modified rock drill on a column “ Jackhammer ” Rock Drill,. (Ingersoll-Rand Company). mounting, with means for swinging it in a plane at any angle. Before leaving this section of the exhibit, we may mention a rock drill for submarine work with a 61 in. diameter cylinder, which is claimed to be the largest ever constructed for this purpose. The Ingersoll-Rand Company also show a hand- operated “ Calyx Diamondless ” core drill, using chilled shot or steel cutter, for deep boring and prospecting work. These machines are provided to bore up to a depth of 4,000 ft. Also a Leyner drill sharpener, of standard type, and photographs of air locomotives, &c. BEVER, DORLING AND CO. LIMITED. Messrs. Bever, Dorling and Co. (Bowling Ironworks, Bradford) exhibit their new patent safety winding engine controller, which is shown in the accompanying figure. This apparatus consists of a governor connected with two cams, one of which is connected with the brake lever and the other with the lever of the stop valve. The two cams can be adjusted independently, and by this means the cam operating the stop valve can be adjusted to close the latter ; and if this is not sufficient to reduce the speed of the engine, the cam operating the brake lever comes into action and the engine is pulled up. By this means the disadvantage of suddenly apply- ing a powerful brake to the engine running at high speed is avoided. The cams make one revolution in the wind, and the profiles of the cams are so formed that the predetermined speed at any portion of the wind cannot be exceeded. In addition to safeguarding the engine from excessive speed during the wind, an adjust- able stop piece in the cams is so arranged that the engineman can lift the cage above the fallers, but not beyond. Should he run beyond this position, the over- winder acts at once and shuts off steam and applies the brakes, and thus stops the engine. This same action takes place if the engine is started in the wrong direc- tion. The governor is driven by a shaft from the engine, and this shaft by means of a worm and worm wheel drives the cams. By a simple arrangement of pointers the engineman can always see when he is approaching a dangerous speed. One pointer is fixed to the overwindei- and another to the rod connecting the stop valve; and by keeping the latter above the fixed pointer, the arranged speed cannot be exceeded; but if the two pointers come opposite each other, the automatic arrangement of the overwinder immediately comes into action and pulls up I .V ■ ' (joss' j L ‘A : -w ■ ;5-i \. k Iv ' / ft'- ’ , >.'Ju. ' ’■•“Ml A.’. ’ • • ' Renold Chains Driving Screening Plant at the Askern Main Colliery. the engine. Amongst the ad\antages claimed for this overwinder are the separate control for the stop valve and brake allowing the time when these come into action to be separately adjusted to the most suitable position. In addition an attachment has recently been added to the brake, by means of which the pressure is applied at a speed varying with the position of the cages in the wind. This is done by means of a cataract cylinder, which is controlled by one of the cams on the controller. Messrs. Bever, Dorling and Co. also exhibit a new system of saving the shock to the cages when coming on to the keps or fallers. This is done by a very simple method of springs contained in a hollow cup on the top of the fallers. It is an invention of Mr. David Bannister, engineer, of Messrs. Crawshaw and Warburton Limited. HANS RENOLD LIMITED. Messrs. Hans Renold Limited (Progress Works, Brook-street, Manchester) show steel driving chains and wheels for power transmission, and also for elevating, conveying purposes, &c. The chains are shown in three main types—silent, roller and block. In the silent type there is a 145-horse power drive with a speed reduction A B C Knock off for Overwind or Winding Engine Controller. (Bever, Dorling and Co. Limited). of 480 to 85 revolutions per minute; chain speed (when running), 1,200 ft. per minute. The chain width is 12 2 in., with a 1| in. pitch ; minimum breaking strength, 107,100 lb. In striking contrast to this is a 1-horse power drive with a speed reduction of 150 to 500 revolu- tions per minute ; chain speed (when running), 1,187 ft. per minute; 0 65 in. wide, A in. pitch ; minimum breaking strength 1,9001b. In addition, of course, samples of the various sizes of bush and patent liner silent chains are shown. A 3 in. pitch roller chain drive with a minimum breaking strength of 8,6001b. is exhibited, and also a J in. pitch with a minimum breaking strength of 1,600 lb. Two strands of the block type of chain are shown with elevator buckets attached, and also various samples of standard block and adapted block chains. Many interesting photographs are shown on the stand, illustrating the various uses to which Renold chains are put in collieries, such as driving haulage gear, conveyors, tipplers, screening, washing machinery, &c. The illustration which we give shows a particularly interesting application of Renold chains driving colliery plant at the Askern Main Colliery. These chains are driving two picking belts, a scraper conveyor and inspection belt. The chains shown are the Renold “ long pitch ” series of bush roller chains. The plant was erected by Messrs. Plowright Bros, under the ’ supervision of the managing director, Mr. Joseph i Humble. Incidentally it may be mentioned that the I whole of the screening plant at this colliery are driven ! by Renold chain gearing. GEORGE M. CALLENDER AND CO. LIMITED Messrs. George M. Callender and Co. Limited (25. Victoria-street, London, S.W.) show example of cooling pond rendered watertight with Callender s sheeting, invented by them nearly 40 years ago. In the centre of the tank is a column of loose porous bricks, under the top course of which, just above water level, is inserted a small piece of “ Callendrite ” dampcourse. Other features of the exhibit are the “ Ledkore ” lead and bitumen dampcourse, composed of a core of sheet