2483. Br³ning, G. Jan. 31. Moulding - machines. - A machine for moulding toothed wheels automatically moulds tooth after tooth without any hand control. The driving- shaft l carries two feathered clutches o, p, the former of which may drive the gears 19 or q, or occupy an intermediate non-driving position while the latter drives the bevelgears 33 or r. Commencing operations in the position shown in Fig. 2, a rotable box e, adjustable by means of its sliding bearing h, has a templet a for one or more teeth therein. A stamper c, reciprocated by a crankdisk u driven through gears t, s, q, rams sand supplied from a hopper d by a worm driven through a clutch 14, gears 6, 7, shaft z, and gears y, x, w, r. The shaft z is threaded and, as it rotates, slowly raises a frame 2 which carries the disk u so that the stamper rises as the tooth space is filled. The frame 2 also carries bars with stops 8, 39, 11, 31, 40 and when the tooth space is filled the rising stop 8 acts on the arm 9 to throw the lever 10 from position I to position III stopping the reciprocation of the stamper, and, by means of gears 19, 20 and a crank-arm 22, raising the templet a. At the same time, the stop 11 unclutches the sand-feeding worm by engaging the lever 12. A wiper 15, Fig. 7, acted on by a spring 17 has a roller 16 pressing against a cam-face 18 on the templet and when this rises the wiper wipes across the top of the tooth and remains until the returning templet forces it back. The disk 21 carries a few teeth 24, which, at the highest point of the templet, engage the gear 25 and so rotate the box e through a chain 26, gears 27, 28, and worm 29. Just as the templet reaches its highest position, the stop 31 throws over the lever 32, giving a rapid reverse motion to the screw z through the gears 33, y. While the stamp is thus being lowered, the templet reaches its lowest position for a new tooth or teeth, and a projection 34 on the disk 21 engages a projection 35 moving the lever 10 into a non-drive position II. When the frame 2 &c. reaches its lowest position, the stops 9, 40 simultaneously throw over the levers 10, 32 into the positions shown, and the cycle of operations recommences. In a modification, the stops 8, 34, 35 are dispensed with, and the lever 10 is operated by the stop 39 which engages a pawl 41, Fig. 5, releasing the lever 10, which falls from position I to position III. The further movement of the pawl 41 turns the lever 43, which acts on the tail 44 of the lever 10, moving it into position II and there retaining it. When the frame 2 falls, the stop 39 acts on the tail 44, moving the lever 10 into position I where it is held by the pawl 41 engaging the projection 42. |
The invention relates to a method for directly producing an investment casting mold by machining a sand mold produced using hardenable bonding agents. In particular, the wear of the tools should be reduced and the dimensional accuracy and precision should be increased during the reproduction of the mold. To this end, a blank mold (1) to be machined is produced while using a variable or fixed casting box (2) having a model assembly (4). Said blank mold comprises specified contours, with regard to volume, of the casting mold and a machining allowance for the milling of the molding material. After filling the casting box (2) with hardenable foundry molding materials, after hardening and after removal from the mold, the blank mold (1) is converted into the casting mold by removing material according to the machining allowance by means of high-speed machining, milling or three-dimensional machining of free-formed planes. The invention relates to investment casting molds for castings made of metal, and to the production of cast part prototypes and individual pieces having small and medium dimensions and masses. |