Pavement corer and method

Abstract

A pavement coring machine having rotating cutting heads of various diameter, the optimum speed of rotation of the heads varying with the diameter of the cutting head and the nature of the pavement being cored has a direct reading tachometer positioned to be observed by an operator of the machine, the tachometer being operatively connected to display the speed of rotation of the cutting head. A method of operating the machine includes determining the optimum speed of rotation of a cutting head, and regulating the speed of the cutting head as displayed by the direct reading tachometer.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:  
     
         1 . In a pavement coring machine having rotating cutting heads of various diameters, the optimum speed of rotation of said heads varying with the diameter of the cutting head and the nature of the pavement being cored, the improvement comprising a direct reading tachometer positioned to be observed by an operator of the machine, said tachometer being operatively connected to display the speed of rotation of said cutting head.  
     
     
         2 . In a pavement coring machine having rotating cutting heads of various diameters, the optimum speed of rotation of said heads varying with the diameter of the cutting head and the nature of the pavement being cored, the improvement comprising a manually settable speed control having indicia representing diameters of said cutting heads, whereby when said speed control is set at a chosen indicium, the cutting head is rotated at an optimum speed.  
     
     
         3 . The method of operating a pavement coring machine having heads of various diameters comprising determining the optimum speed of rotation of a cutting head, dependent upon the diameter of the cutting head, and regulating the speed of the cutting head as displayed by a direct reading tachometer.  
     
     
         4 . The method of  claim 3  wherein the speed of rotation of the cutting head is maintained automatically, subject to a manual override by the operator of the machine.  
     
     
         5 . A method of coring a pavement comprising cutting a circular core by utilizing a pavement coring machine having rotating cutting heads of various diameters, the optimum speed of rotation of said heads varying with the diameter of the cutting head, determining the optimum speed of rotation of the particular cutting head being used, rotating said cutting head at said optimum speed, regulating the speed of the cutting head as displayed by a direct reading tachometer, thereafter drilling a hole through two broad faces of said core, anchoring an eye-bolt in said hole, and lifting said core by means of said eye-bolt.