June 6, 1913. THE COLLIERY GUARDIAN. 1203 COAL WEIGHED AUTOMATICALLY “AVERY” PATENT CONVEYOR WEIGHER &TOTALISER. s ■ W&r AVERY L™ MAKERS ’ BIRMINGHAM . THE AVERY This Machine AUTOMATICALLY Weighs, Registers and Totals the Net Weight of Material Passed on the Conveyor over the Weighbridge. W. & T. AVERY Lit SOHO FOUNDRY, BIRMINGHAM. - .......................................................................... ■■■............. .. . 1 ■■ .............. 111 ------- .5 out—and another interesting exhibit is a six-throw motor- crank shaft, this shaft being forged and finished complete at the company’s forge. THE FLOTTMANN ENGINEERING CO. LIMITED. The Flottmann Engineering Company Limited, of Cardiff, have a fine display of their- well-known hammer drills. In the comparatively short period of seven years from its first introduction to the present time no less a number than 32,000 Flottmann hammer drills have been sold, and notwithstanding the tremendous output of these small machines, and the enormous number of blows delivered on the drill steel—2,500 blows per- minute—they have proved singularly economical, con- sidered from the standpoint of maintenance. On the company’s stand machines for boring work under all conditions may be seen. Type “ E ” for quarry work bores holes to a depth of 20 ft., finishing the hole at that depth Ijf in. diameter. This machine is made with extra powerful rotative action, and easily turns a drill 20 ft. long. Although the machine is designed and made for this heavy duty, it is but 40 lb. in weight, and is easily operated by one man. There is besides a whole range of machines exhibited suitable for boring holes of a lesser depth, and machines of various weights for boring holes upwards, and at all angles, and suitable for holes of one yard, two yards, and intermediate depths, to the depths already mentioned. The machines shown are made to suit the varying requirements of the whole range of mining. All are intended to work by compressed air, but to meet special conditions, where it is not convenient to instal com- pressed air plant, a machine has been designed that works by steam, and has been found to give great satis- faction for quarrying and such like work. It has a boring capacity similar to those designed to work by compressed air. Undoubtedly the patented ball valve is one of the main features of the Flottmann drill. The valve, the object of which is to give the reciprocating action to the hammer or piston, is situated at the junction of the top and bottom ports of the cylinder. The two ports each terminate in a neck bush seating which face each other. Between the two seatings there is sufficient space for a solid steel ball, which moves in. from one seating to the other. When this ball valve is resting on one seating, the other seating is open to pressure, which acts on the piston and causes it to move along the cylinder. When the piston has travelled about three-quarters of its stroke, it uncovers an opening in the side of the cylinder, through which the pressure partly escapes, and thus produces a differential pressure on two sides of the ball valve. This differential pressure causes the ball valve to move against the opposite neck bush or seating, which is thus closed to pressure, and at the same time the opposite post or seating is opened. This completes the cycle of operations, which then repeats itself. The fact of the ball valve having but in. of travel enables the piston to travel with great velocity, and thus, with 801b. pressure per square inch, the piston strikes the drill steel about 2,500 times per minute. Part of the exhaust pressure passes through the hollow drill steel to the end of the hole, being bored, and blows the cuttings out of the hole. On the piston rod are four spiral grooves, into which project corresponding lugs on the inner side of a ratchet wheel, through which the piston rod passes. There are two pawls on the exterior of the ratchet, which allow the ratchet to rotate when the piston is giving its forward or striking stroke. On the back or return stroke of the piston, the pawls hold the ratchet wheel, and thus the piston has to rotate the amount of the angle of the spiral grooves on the piston rod. As the piston rotates through this distance, a similar movement is communicated to the drill socket or drill holder, in which the end of the piston rod works, and thus the drill holder is rotated, and therefore the drill, which is inserted in the drill holder, receives a rotative movement. By this arrangement, the piston on the forward stroke strikes the drill; on the backward stroke it turns the drill. The operator inserts the square shank of the lower end of the machine, places the point of the drill against the rook to be bored, and turns on the pressure. The piston in the machine strikes and turns the drill in the manner as above described, and blows the cuttings out of the hole as it bores. On the stand, a full-sized hammer drill in section, so arranged that the parts may be moved by hand, explains the action of the machine, and a complete set of parts shows the excellent workmanship and care with which the machines have been made. Mounted on a column is to be seen one machine supported on a screw-feed carriage, and one with an air-feed attach- ment. These fittings prove their utility under special conditions. Exhibited is further a set of hollow drills up to 20 ft. in length for quarry work or for pit sinking by the cementing process, hollow and twist drills up to 6 ft. 6 in. in length, with cutting bits of different shapes, hoses for airland steam, and the necessary fittings. FOUR OAKS SPRAYING MACHINE CO. LIMITED. This firm show spraying and lime-washing machines for use in mines for limewashing stables, underground roadways, &c. RICHARD JACOBSON. An exhibit of considerable interest in view of recent legislation is shown by Mr. Richard Jacobson, the well- known firm which makes a specialty of life-saving, health and safety appliances. Mounted on lifelike dummies is the well-known “ Draeger ” self-contained oxygen breathing apparatus, as used by a great many rescue stations and mines throughout the world. Of particular interest is the “ Draeger ” pulmotor apparatus for automatic artificial respiration. This apparatus, which has made very rapid strides on account of its efficiency, and is installed in consequence at nearly every rescue station in this country and abroad, and of which there are at present about 1,500 in use, is demon- strated by showing how it inflates the lungs with highly oxygenated air, and then drawing off the poisonous gases, in an almost lifelike manner. Other apparatus and implements for saving life, property and suffering, are represented by various kinds of air-bellows, smoke helmets, amongst which is the well-known “ Durham ” helmet, which is in use through- out the Durham and Northumberland collieries, smaller and simpler reviving apparatus and inhalers, ambulance chests and boxes, miners’ electric safety lamps, fire extinguishers, &c. A novel exhibit of this firm is the self-contained diving apparatus for use in flooded mines—a small diving dress which can be donned in a few minutes, allows not only a person to dive down a flooded pit, but also allows men imprisoned to rise to the surface. A. HANLEY. Mr. A. Hanley, of 21, Alpha-road, Bristol, shows a number of his “allright” appliances. These include his well-known safety catch and safety belt, as well as corner- plates for wooden pit tubs, drawbars, pedestals, clips, coupling tallies, side-brackets, buffer caps, &c., and a variety of oils, greases, paints and varnishes. KIMBER DRILL AND ENGINEERING CO. LIMITED. This firm show the “ Kimber ” chisel bit sharpening machine. The pneumatic hammer is actuated by and attached to the machine itself, and does not require a separate compressor; after a worn drill has been pared by means of the cutters, this device rapidly hammers up the extreme edge of the bit, and generally improves the lasting quality of the drills. With this machine one man, it is claimed, is capable of sharpening 250 drills per hour. A coal furnace, capable of heating sufficient drills to keep the machine going, is also supplied with each machine. (Continued on page 1210).