Patent GB-190604300-A (GB)
Title: Improvements in Apparatus for Casting Curved Stereotypes.
Inventor: HOPKINS CHARLES EDWARD
Filed: 1906-02-21
Granted: 1907-02-21
Abstract: 4300. Hopkins, C. E. Feb. 21. Stereotype. - Relates to improvements in apparatus for casting curved stereotypes, particularly applicable to the machine described in Specification No. 12,850, A.D.. 1903. Between the metal pot 3 and the furnace frame 2 is a fire-brick baffle 1, Fig. 1, provided with two ports 6, 5, the former being adjacent to the chimney 7 and fitted with a damper 8, and the latter surrounding the valve chamber 4. The damper 8 is kept open until the metal is melted, and is then closed to heat the valve chamber during the casting operation. The metal pot is provided with a cover 10 formed with a raised central portion 12 to which is pivoted a feed - door 11, normally kept against its seat 13 by a counterpoise 15. Mounted on pivots 17 in the cover 10, and connected by links 18 to posts 19 on the door 11, is a platform 16, which when weighted by a charge of metal opens the feed-door 11, allowing the charge to be fed to the metal pot, after which the door is closed by the counterpoise 15. A metal stirrer 20, in the form of a propeller, is carried on a rotary shaft 21, beneath a grating 26, the shaft 21 being driven by any suitable means such as worm gearing 25, a shaft 24, and a pulley 23. A single metal-distributing valve is provided, and consists of a plunger 49 having a tapered nose 50, adapted to engage a corresponding seat 51<a> in the cope 29, which seat is surrounded by the cooling- chamber 60. The plunger 49 slides in guides 51 and is formed with a rack 58 gearing with a pinion 57 on a rod 56, which is operated by bevel-gearing 55 from a shaft 53 carrying a handle 52. In order to provide for the expansion and contraction of the metal pot and to secure a good fit between the nozzle and the cope and between the cope and the drag, the cope instead of being secured directly to the metal pot is bolted by means of three lugs 61 to a frame 66, which is secured, somewhat loosely. to lugs on the metal pot on each side of the valve chamher. The frame 68 supporting the drag is also secured to the frame 66. The convex face of the cope 29 has two transverse ridges 40, 41 which form the top and bottom of the mould, respectively, instead of rings on the drag, the former of which may be detached from the cope to permit of the mould being filled from a hand-ladle. Above the valve may be provided an intermediate ridge 42 reduced in depth at each end, forming a metaldistributing chamber 43 and leaving a somewhat restricted passage to cause a steady flow of metal. A groove or projection is produced at one end of the concave face of the plate to facilitate trimming by a ridge or groove 48 on the cope. The drag D consists of a bottom D', and a semicircular platecarry ing frame D<2>, comprising straight side bars and thin steel semicircular pieces 46, capable of being locked automatically to the bottom D' by hooks h<3> and studs h<4>, which carries the cast plate to the trimming-cylinder. The bottom D' runs by means of rollers 106 on ways 75, and is provided with a slotted guide 72, which engages a bar 74, to assist in turning the drag up to the casting position against the cope. During the first motion of the operating-toggle 75<a>, the bottom D' turns on the rod 74, the inclined portions of the guide 72 sliding on the rod. The continued motion of the toggle causes the rod 74 to enter the part 73 of the guide and the drag to approach the cope in parallelism. After the plate is cast, the reversal of the toggle causes the drag to recede in a similar manner, thus preventing binding of the ridges or grooves on the cope with the cast plate 100. The bottom D' is maintained at the correct working temperature by two water circulations 70, 71, the former for cooling the part of the plate near the valve, and the latter the body of the plate. The side of the mould is closed by bars 28 recessed in the cope and the casting-bars 76 of the matrix clamps on the drag D. The bars 28 are formed to produce rounded edges 31 on the plate, and one or both of them are provided with a rib or ribs which produce a groove or grooves on the stereotype, with which an angle bar or bars on the holding cylinder subsequently engage to hold the plate while the matrix is being stripped, and which co-operate with guides as the plate travels through the trimming-machine. The matrix clamps, comprising bottom bars 77 and hinged casting-bars 76, are capable of being clamped either to the frame D<2> or to the bottom D<1>. This is accomplished by means of longitudinally-sliding bars 89, provided with taper hooks 92, 94 adapted to engage with ledges 96, 98 on the frame D<2> and bottom D' respectively. The bars 89 are reciprocated by means of a yoke 86, which passes under the drag D and is pivoted on studs 87. Extensions on the yoke engage studs 83 on the bars 89. The yoke is operated by a handle 85. A transverse slide 99 is provided to clamp together the bars 76, 77 while the clamps are being placed in the casting position. In order to provide for possible inequalities in the width of the matrices, the latter, instead of being formed with a convex ridge, are formed with upstanding edges 79, Fig. 29, the shoulder 104 producing a groove and the edge 81 of the casting- bar 76 a narrow bevel down the edge of the plate. Several, preferably three, sets of casting-apparatus are arranged round a single metal pot.