Improved Quartz and ore Crusher.

Cromwell Argus, Volume III, Issue 137, 25 June 1872, Page 7

Improved Quartz and ore Crusher.

The impetus which mining enterprise has lately received by new discoveries of rich deposits of tin, gold, and other metals in various parts of the Colony, has offered a great inducement to engineers to perfect or improve machinery used for mining purposes. One of the principal machines used in the production of gold, tin, &c, is the quartz-crusher. These machines, as most people are no doubt aware, consist of bars loaded at one end wi:h blocks of iron. The " stamps" are raised by means of earns revolving upon a horizontal axle, and are allowed to fall by their own weight, or, as in some instances, an extra amount of force is given by means of spri lgs. These are the main features of the machines now in use. The speed with which the blows are struck is necessarily limited, not exceeding perhaps sixty or seventy blows per minute. The same force, whether for line or coarse quartz, has to be used. Several machines, in which the use of steam to produce the blows of the hammers has been used, have been invented, but none of them have been so successful as to supersede the pros >nt arrangement with weighted bars. The difficulties in the way of a successful application of steam to produce a crushing power have, however, at last been overcome by the invention of 7\lr Norman Selfe(of Mort's Engineering and Dry Dock Company, Sydney,) and for which he has just taken out a patent. The principle of Mr Selfe's machine consists in having a steam hammer ; but it differs from all steam hammers hitherto constructed in having a constant pressure of steam to raise the piston and hammer, and an intermittent power to cause it to descend and give the blow. In previous machines, steam has been employed to raise the piston ; but the piston, when so raised, has been allowed to fall by its own weight. This new machine has no levers, springs, or toppets—the only moving parts being the piston, with its stamper, or hammer, and a solid plug which acts as a valve. The liability to derangements is thus reduced to a minimum. In all ordinary steam hammers, whether a long or short blow is given, the same amount of steam is used. In Mr Selfe's machine, the amount of steam used may be regulated according to the length and force of the blowrequired. The main principle of this invention is thus set forth in the specification, upon which letters patent have been granted:— " This invention consists of a steam hammer, or stamper, actuated by a piston within a cylinder, so constructed that a continuous pressure of steam or air overcomes the gravity or weight of the hammer, stamper, or piston, and acts with a constant force to raise them; whilst an intermittent power of steam, or compressed air or gas, acting on the upper surface of the piston, and regulated by a valve, causes the same to descend and strike a blow ; by which arrangement steam only is used in proportion to the length of blow given, no power being consumed to lift the

hammer; also a valve so constructed as to work by the action of the stamp without tha intervention of rods, cranks, tappets, or levers ; also arrangements and combinations of arrangements for causing a revolution of the piston and hammer in either its upward or downward stroke ; also an arrangement for shifting the cylinder to adjust the length of stroke, and compensate for the wearing of the 'shoe' or 'hammer head.' This invention is especially applicable for sieam hammers, ore stampers, rock drilk, or for any other purpose where a reciprocating motion is required more powerful in one direction than the other. It is intended to be used with steam, compressed air or gas, or water pressure ; and as only so much of the cylinder is filled and exhausted at every stroke as the piston actually descends, and as ordinary steam hammers till their cylinders only to lift a small height when the piston is near the top of the stroke, this arrangement effects a very considerable saving of power. The absence of all levers, cams, eccentricities, or joints, renders the machine easily managed, and not liable to become easily deranged." These machines tike up scarcely so much room as the ordinary machines with cams. By the latter only about sixty or seventy blows of the stampers cm be produced per minute ; by tills new machine, nearly 200 blows per minute can be produced. The force of the blow, too, may be just sufficient to crack the shell of an egg, or to crack the hardest rock. In the course of a few days, a public trial of the machine will be made. Mr Selfe is securing patents in the other Colonies for his invention.— Sydney Paper.