GB952459A - Improvements in and relating to transportable concrete mixers - Google Patents

Abstract

952,459. Vehicle concrete mixers; hydraulic operation. HUTSONS Ltd., and J. M. WALFORD. April 28, 1961 [April 28, 1960], No.14970/60. Heading B 1C. [Also in Division F2] In a rotary drum truckmounted cement mixer (see also Division F2) the drum 10 is driven by hydraulic motors 17a, 17b, Fig. 1, mounted on a common shaft; the motors may be arranged in series to give higher speed and lower torque, or in parallel for lower speed and higher torque. Pressure fluid is supplied by a pump 12 driven by the vehicle engine 11; the direction of rotation of the hydraulic motors is controlled by the manually operated starting and reversing valve 15, Fig. 4 (not shown), and the connection of the motors in series or parallel by the manually operated selector valve 16, Figs. 5-8 (not shown). A by-pass valve 19a, Figs. 2 and 3 (not shown) supplies pressure fluid to a motor 32 driving a metering pump 30 supplying water to the mixer ; the valve 19a is arranged to supply a constant quantity of pressure fluid to the motor 32 irrespective of momentary pressure fluctuations. In an alternative arrangement, Fig. 9, the two motors 17a, 17b are replaced by a single motor 17 having two sections giving differentspeeds of rotation and intended for alternative use, and the selector valve 16 is arranged to supply either section.