GB461843A - Apparatus for measuring the resistance of substances to grinding - Google Patents

Abstract

461,843. Conical mills. KUHN, I., and BRABENDER GES. Feb. 17, 1936, No. 4848. Convention date, Feb. 15, 1935. [Class 59] [Also in Group XIX] In a process for measuring the resistance to grinding of materials which can be finely divided by rough grinding, the test material is rough ground and its resistance to grinding is directly measured. Apparatus for carrying out this process comprises a normally stationary and a rotating grinding member and means connected to one of the members for giving a measure of the stress placed upon it during grinding due to the resistance of the material to grinding. A normally stationary grinding head a mounted on a shaft c is surrounded by a cylinder d into which the material is fed by a pipe z inclined oppositely to the direction of rotation of cylinder d. The latter is supported in a leather-lined frame f and is threaded at i to a cylinder h with teeth j driven from wheel k on a hand-rotated shaft l. Threaded on to cylinder h and fixed by a stud p is a part o with flange o<1> under which is a ring r: this ring is clamped to the flange o<1> by a stud t and a stop s which co-operates with a scale marked on flange o<1> and with a stop v rigid on cylinder d. When the parts are rotated and owing to the thread i the amount of rotation which stop s makes before it meets the stop v and carries cylinder d with it, determines the amount of opening g between parts a and d through which the ground material falls into a tray z. By loosening stud t and moving the stop s over its scale, the amount of the opening g may be adjusted. The shaft c of head a is anchored to one end of a spring 3 the other end of which is fixed to a stationary housing 2. Attached to shaft c is a wheel 4 geared through train 5, 6 to a fan for steadying the action. Wheel 4 also has a stop 10 coacting with a fixed stop 11. A pointer 12 on shaft c reads over a scale 13 : attached to the cover glass 14 is a manually adjustable pointer 15, 16. The material falls down pipe z until its mouth is covered by the delivered material : since this pipe is inclined against the rotation of cylinder d the latter is kept automatically full. As the hand shaft l is rotated, cylinder d coarsely grinds the material against the head a and the resistance of the material to grinding rotates the head a, stressing the spring 3 and moving the pointer 12 over scale 13. Shaft c or indicator 12 may be provided with a known recording device. The cylinder d may be the normally stationary member and the head a the rotated member.