Patent GB-661982-A (GB)
Title: Improvements in or relating to apparatus for extracting articles from a furnace
IPC: C21D9/00
Filed: 1949-03-11
Abstract: 661,982. Charging apparatus. ELECTRIC RESISTANCE FURNACE CO., Ltd., and COOK, A. J. March 11, 1949, No. 6683/49. Class 51 (ii). Extractor apparatus for withdrawing billets and the like from a furnace comprises a plurality of arms which are moved forward into the furnace underneath the billets, are then raised with the billets thereon and withdrawn, the billets being deposited outside the furnace. As shown, the apparatus comprises arms 10 connected at one end to a travelling frame 11 carrying a platform 12 on which a motor 13 is mounted, the frame being suspended from overhead tracks 14. The free end of each arm 10 carries a lifting surface 29 and a vertically moving platform 15 which has an extension 16 and is pivotally connected to a lever 17. The rear end of 16 is connected to one angle of a triangular bell-crank 18 which is pivotally mounted at 9 on the arm 10, the third angle carrying a roller 19. A trolley 20 slidably mounted on rollers 21, 211, in slots 22, is connected to a slidable member 23 driven by a chain 25. The trolley is formed with an inclined surface 27 and horizontal top 28 such that on the trolley moving towards the free end of arm 10 the roller 19 will mount the trolley and finally rest upon the surface 28, thereby raising the platform 15 to the position shown dotted in Fig. 2. The trolleys on the two outer arms carry between them a push-bar 31. Trolley movement is controlled by two cam-operated switches, one stopping the trolleys at the end of their forward travel and reversing them, the other stopping them at the end of their reverse travel. A third cam-operated switch is controlled by movement of the trolleys and on being opened when the rising platforms 15 have cleared adjacent billets in the furnace causes cessation of the extractor withdrawal stroke. A group of limit switches control movement of the extractor, the switch to be used at any time depending upon the crosssectional size of the billets. In dealing with stacked billets such as shown in Fig. 2, the extractor is set in forward motion, the lifting surfaces 29 entering the furnace below the billet 34. When the limit switch head 33<SP>1</SP> comes into contact with 34 the extractor continues to move forward until the front ends of surfaces 29 are ¢ inch past the back face of the billet, when the selected limit switch arrests the movement of the arms. The whole extractor is then raised by a gear (not shown) coupled to the track 14 and the arms 10 commence their withdrawal stroke. At the same time trolleys 20 move forward, operating the switch to stop the extractor and the bar 31 pushes the billet 34<SP>1</SP> on to the raised platforms 15. The trolleys then reverse, the platforms are lowered and the billet 341 is positioned on supports in the furnace. The trolleys complete their backward travel and. just before they reach the end thereof the extractor recommences its backward stroke, withdrawing the billet from the furnace. The billet is then lowered on to a suitable support or a conveyer. The bar 31 is removed when the extractor is dealing with single, i.e. unstacked, billets.