GB724287A - An extension cable sheathing press with stationary press-head - Google Patents

Abstract

724,287. Hydraulic presses. HYDRAULIK GES. Oct. 31, 1952 [Nov. 23, 1951], No. 27516/52. Class 69 (2), [Also in Group XXII] An extrusion press for sheathing cables with light metal and light-metal alloys comprises a stationary press-head, containers for the metal mounted at opposite positions on the presshead, movable cross-heads mounted one at each side of the press-head, main hydraulic pistons secured to the cross-heads said pistons moving rams in opposite directions towards the presshead and a hydraulic compensator by which a balancing of the pressures exerted by each ram is secured when the resistances to pressure differ. The extrusion press comprises two opposed containers 2 and 3 for receiving billets 4. Rams 5 and 6 are mounted on cross-heads 7 and 8 operated by pistons 9 and 10 in cylinders 11 and 12 respectively. Secondary pistons 13 are connected to the cross-head 7 and said pistons operate in cylinders 14 on the container support 15. The cylinders 14 are connected by a pipe line 16 to cylinders 17 containing cooperating pistons 18 attached to the cross-head 8. Similarly secondary pistons 20 are provided on the cross-head 8, said pistons acting in cylinders 21 connected by pipe-line 22 to cylinders 23 containing co-operating pistons 24 attached to the cross-head 7. In operation, if one ram should lag behind the other, additional pressure is fed to the cross-head of the lagging ram by the secondary piston of the other ram so that an exactly equal and oppositely directed motion of the rams is automatically obtained. The secondary cylinders 14 and 21 may be used for effecting the return stroke of the ram by incorporating control means 25 and 26 in the fluid lines which introduce fluid pressure from the hydraulic main to the cylinders 14 and 21. In another embodiment the piston 10a (Fig. 2) in cylinder 12a has a larger diameter than the piston 9 and the secondary pistons 20 transmit fluid pressure to co-operating pistons 24. Thus the working pressure of piston 9 which is less than that of piston 10a is constantly augmented by pressure from the secondary pistons 20 on the co-operating pistons 24 and synchronization of the rams is obtained. Additional pistons 30 in cylinders 31 are provided for the piston 9 when the piston 9 is larger than piston 10a in which case the synchronization of the rams is effected by connecting the cylinders 31 to the hydraulic main so that the pressure in the pistons 30 acts against the pressure in the piston 9. The pistons 30 may also be used as returnstroke pistons.