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About the same time that the cone crusher appeared, at least three different builders appliers applied the principle of curved-profile crushing chambers, certainly the most important and far-reaching improvement in crusher design that had been made for many years-possibly the greatest since the inception of the gyratory type. In our own case this development took the form of “non-choking” concaves, which could be installed in any of the existing models of gyratory crusher without any change in the shape of the crushing head, the type quickly became standard equipment in our reduction crusher, the Newhouse and Superior Mc. Cully fine reduction machines. But of equal importance was the fact that the efficiency of many hundreds of existing standard machines, of all ages and styles, was markedly improved at a very nominal cost by substituting these new curved concaves for the of straight-face liners.
All crushers developed up to this time, except the very large machines of the gyratory type, were provided with some means of adjustment to compensate for wear or to adjust for variations in product size. The range of adjustment in most machines was small; adjustments in most cases required shutting down the machine. In the gyratory types, after a certain amount of adjustment was made, tit was necessary to reset the concaves. This did not constitute any serious drawback in primary and secondary crushing service, because wear was slow generally and the exact setting of discharge opening was not a critical matter. With the increase in demand for fine crushing the situation altered; it was necessary to set crushers close and to maintain the setting
within closer limits. It was immediately apparent that a crusher closer and to maintain the setting within closer limits. It was immediately apparent that a crusher with a large range of adjustment, without the necessity of resetting the wearing parts, would be very desirable; as a matter of fact, the first cone crushers brought out incorporated such a feature, which proved to be very popular. |
