Patent GB-753446-A (GB)
Title: Apparatus for vulcanising a rubber sole on a boot or shoe and control mechanism therefor
IPC: B29C35/00
Filed: 1952-02-15
Abstract: 753,446. Moulding rubber soles on to shoe uppers. CRAECKER, A. DE. Feb. 15, 1952 [Feb. 15, 1951], No.' 4044/52. Class 87(2) A machine for securing rubber soles on boots or shoes by vulcanization comprises one or more lasts, side by side and means for pressing each last against a rubber sole head between mould members against a hot plate, a system of cams, operated by a control lever, enabling a last to be extended when pressed against the sole and to be contracted when lifted away. A last is in two parts, 17, 18, one or both of which may be heated electrically, the current being conveyed through clip rings, and they are held apart, when the last is extended. Fig. 1, by a spring 42. The lasts are swung from the vulcanizing position, Fig. 1, around a spindle 27. to a position, Fig. 10, where they are inverted and shoes are placed on and removed from them. The rubber soles are held between moulding members 12. 13 on a cast metal plate 9 heated by radiation from an electrical resistance heating element 11. The mould members are bolted to the plate 9 and the bolt holes are grooved to allow steam to escape. Each last is supported, through a lug 19 on the part 18, from a pair of side plates 22 which in turn are held between side plates 24. the ends of these plates 24 being welded to a sleeve 26 on the spindle 27. The plates 22 can be adjusted relatively to the plates 24. about a spindle 30, by a bolt 32 in slots 33. The cam system is shown in Fig. 4 and comprises a member 38 pivoted 'on the spindle 30, a member 41 pivoted to the side plates 22 at 103, and a member 44 pivoted to the side plates 22 at 45 and comprising a projection 47 and a hook 46. In the Fig. 10 position, the end of a rod 36 bears against a stop 48, and the thrust on the rod turns the cam members 38 clockwise as seen in Fig. 4 and causes it to press on the member 41 in a direction to move a double-arm lever 43 to operate a rod 35 which moves the part 17 towards the part 18, so contracting the last and enabling shoes to be put on or taken off it. The last can be extended in the Fig. 10 position by the depression of a pedal 67, Fig. 1, which, through a cable 68, moves a rod 134, Fig. 11, to swing the stops 48, which are pivoted on a plate 131, to a position where they free the rods 35. In the Fig. 1 position of the last the rod 35 is moved to separate the parts 17, 18 by receiving a lever 51 which, through a friction clutch, moves a rod 50 with a T- 'shaped head 55 into engagement with the hook 46 (a double guide member 56 suitably guiding the rod 50) and causes the projection 47 to turn the member 41 whereby the double-arm lever 43 moves accordingly. A projection formed on the lever 51 is movable in a slot in the end face of one of the clutch elements and, at the end of the movement required to engage the head 55 with the hook 46, effects a positive drive from the lever 51, the clutch then slipping. When the lever 51 is completely raised the last is extended as far as possible and is clamped down on the plate 9. On downward movement of the lever 51 an adjustable member 66, carried by a projection 65 from the lever, engages the lever part of the rod 50 to withdraw it from the double guide 56 and further movement of the end 50 is effected by the movement of the lever 51 in frictional engagement with the clutch. To give an alarm signal if the shoes press the soles down on the heating plates for too long a contact plate 90 is slowly raised while the lever 51 remains in its up position. In this position a disc 80 is in contact with a slowly rotating drum 77, the drum 110 on which it is mounted being no longer raised by the tension in a cable 83 since in the up position of the lever 51, the end of a cable 85 is wound on the spindle 54 of the lever, so raising a lever 81 to which the cable 83 is connected. Rotation of the disc 80, by friction from the drum 77, causes a pulley 88 to rotate slowly, mounted with slight friction on the spindle 109 of the disc. A cable 89 is thus wound on the pulley, so raising the contact plate 90, which is suspended from it in such a manner that it first meets a terminal 91 and causes a warning lamp to light and then if the lever 51 is not lowered, meets a terminal 94 and causes a bell to ring. The drum 77 is rotated by a motor and its speed may be be regulated to control the time of vulcanization. A third alarm, preferably remote from the apparatus, is operated if more than one last remains on the heating plate for too long. The frame 95, 96 on which the terminals 91, 94 are mounted is movable, restrained between springs 98, 98<1>. The pressure of one contact plate 90 on the terminals is insufficient to move the frame, and if the corresponding last remains down the spindle 109 continues to turn without rotating the pulley 88 but if two or more lasts remain down the combined pressure of their contact plates 90 move the frame 95 96 and this movement is arranged to sound the alarm.