GB1301236A - - Google Patents

Abstract

1301236 Furnace taphole guns DANGO & DIENENTHAL KG 15 July 1971 [18 July 1970] 33234/71 Heading F4B [Also in Division F1] A furnace taphole gun 1, Fig. 1, carried by a boom 2 pivotally mounted on a fixed vertical axis 6 is swung to its withdrawn position shown in Fig. 2 by a fluid-actuated ram 11 pivoted at 12 to a fixed frame 13 and at 8 to a crank arm 7 of boom 2 and controlled by means 14 which reverses the direction of fluid flow to and from opposite ends of the ram as the latter passes through an end dead-centre position. Means 14 comprises a 3-position valve which at the start of gun withdrawal is in position III thereby connecting a supply line 15 to the rod end of the ram. As the latter approaches its bottom dead-centre position an electric switch (not shown) shifts valve 14 to position II in which both ends of the ram are connected to the return line 16 and after the ram has passed said dead-centre position a further electric switch moves valve 14 to position I to complete the gun withdrawal movement. The return forward movement is effected by the same sequence of valve arrangement. The ram is cushioned near the end of the withdrawal movement by partial closing of a throttle valve means of a cam follower 23 in abutment with a cammed surface of the boom 2. In a modification the boom and associated ram are moved over the dead-centre position by an auxiliary ram, or by a fluid or electrically operated rotary motor.