GB701284A - Improvements relating to safety elements - Google Patents

Abstract

701,284. Vibrating-jaw crushers. MUCCHI, L Nov. 13. 1951. No. 26574/51. Class 59 [Also in Group XXIV] A safety element for use in crushing or other machines comprises two members 1, 2 adapted to transmit a compressive force and acting on each other at two points on opposite sides of the line of action of the force, the members being in direct contact at one of the points (4. 5), so that they can turn at this point about an axis normal to the line of action of the force, and in indirect contact at the other (4<SP>1</SP>, 5<SP>1</SP>) through an elastic means 3 which is preloaded to a load equal to that fraction of the limiting load on the element which acts on the elastic means, the load to produce unit deflection of the means 3 being smaller than the increase in the fractional load due to unit deflection of the elastic means, and the maximum load on the means 3. corresponding to its maximum deflection which is reached in the dead-centre position, being less than the limiting lead on the element. As applied to a crushing machine (not shown) in which a movable jaw is swung towards a stationary jaw by a member reciprocated vertically by an eccentric, the safety strut is positioned between one side of the member and a fixed part of the machine and, with a further strut located between the other side of the member and the movable jaw, has a toggle action in swinging the jaw. If uncrushable material prevents swinging of the jaw upon vertical movement of the member and the limiting load on the element is exceeded, the spring 6 will be further compressed until the element collapses and assumes the attitude illustrated in Fig. 3d, the movable jaw swinging away from the stationary jaw into engagement with a fixed stop. The spring 6 is pre-loaded by a bolt 8, Fig. 2, and a link 11 is provided between the members 1, 2 to hold them together after the toggle has been upset.