GB560832A - Improvements in machines for testing the physical qualities of materials - Google Patents

Abstract

560,832. Testing physical qualities. DENISON & SON, Ltd., S., DENISON, H. M. H., and LENTON, A. Sept. 30, 1942, No. 13707. [Class 106 (ii)] A machine for testing the physical qualities of materials. comprises means for co-ordinating the stresses applied to the specimen with the rate of loading or counterbalancing of a steelyard on which is adjustably mounted a poiseweight, the poiseweight being in part mounted on and traversable along a fixed track disposed substantially parallel to the longitudinal centre line of the steelyard. As shown in Fig. 1, the specimen under test 20 is mounted in a holder 21 and movable anchorage 22. The holder 21 is connected by a lever system 25, 26, 27 and 28 to a steelyard 1. To provide for a constant rate of loading the steelyard is traversed by a trolley 3, Figs. 1 and 3, with a front axle resting on the steelyard and the rear axle movable on fixed rails 10. The trolley supports a poiseweight 5 adjustable along a rate of loading scale 7. A nut on the trolley engages a screwed shaft 14 driven by an electric motor 16. This nut can be readily disengaged by an operating knob 18. A linkage 29 operatively connected to the lever 26 actuates an indicating unit 30 provided with a maximum pointer 31. The anchorage 22 is attached to the ram 23 of an hydraulic pressure cylinder 24. The pressure supply pipe 36 is connected by a branch pipe 37 to a chamber with a piston valve 32, Figs. 1 and 4, connected by a spindle 33 to the steelyard and with an exhaust pipe 35, thereby providing means for controlling the speed of travel of the ram to take up the stretch in, the specimen. Instead of a piston valve a screwdown valve may be employed and the hydraulic system may be replaced by mechanical means such as a screwed spindle driven by a motor, the speed of which is under the control of the steelyard.