Patent GB-189826865-A (GB)
Title: Improvements in Hydraulic Die Holders Chucks and Tool Holders for Metal Spinning Apparatus and Lathes specially applicable to the Manufacture of Watch Cases.
Inventor: ECAUBERT FREDERIC
Filed: 1898-12-20
Granted: 1899-05-06
Abstract: 26,865. Ecaubert, F. Dec. 20. Spinning; chucks; toolholders.-Relates to lathes for spinning watch cases, and especially to means for holding them in dies during the operation. The dies 30 after the insertion of the blanks are placed in a chuck D which is tightened by hydraulic pressure. The pressure is produced in the hollow mandrel C by a screw plunger 1 operated by a hand-wheel K, which is preferably made like a bicycle wheel and provided with a pneumatic tyre. The dies are kept in place prior to the application of the pressure by a spring catch 31. The dies are clamped by a short piston F working in a cylinder formed on the end of the mandrel. The piston is packed by a cup-leather 11, the annular space in which is filled with hemp or the like which is retained by a screwed ring 33 in order to ensure the leather moving with the piston. The ring is prevented from turning relatively to the mandrel C by a pin 36, and is tightened on the packing by turning the piston F in the mandrel. The piston has a tubular extension 12 and a spring H for withdrawing it when the pressure is removed. A screw plug 14 is provided for filling or emptying the interior of the mandrel with oil, and the headstock is pivoted at 9 to allow it to be tilted. The screwed plunger 1 passes through a gland Q and packing 27 at the back end of the mandrel, and is keyed to a hub L which is surrounded by the hub 15 of the wheel K. The hub 15 is clutched to the hub L by friction rollers 28, Fig. 5, when moved in the direction for withdrawing the plunger 1, but relative motion in the reverse direction is only resisted by the friction of two rings of cork or leather placed between the flanges of the hubs. This frictional resistance is adjusted and maintained by a ring 19 and spring bolts 20. When the lathe is started, the wheel K lags behind owing to its inertia, and screws up the plunger 1 until the pressure is sufficient to make one hub slip on the other, so that the dies are suitably gripped automatically. The pressure is gauged by a small plunger S acting against a spring U, the movements of which are shown by an index sleeve 25, attached to the plunger S, and moving over a casing T which surrounds the spring and is marked with a series of circumferential lines indicating pressures, so that the indication of the gauge can be read when the lathe is working. The casing T is fixed to the ring 19 so that the pressure on the plunger S tends to reduce the frictional resistance between the two hubs. The roller 35 for pressing out the watch cases is mounted on a stud 29 placed eccentrically in a shaft V which is brought up to the work and rotated by means of a lever. The roller shaft V, as shown in Fig. 4, is itself placed eccentrically in a bush W fitted in a bearing B' which is bored out in line with the bearings of the mandrel, and the arrangement is such that the roller acts downwards in working. The hydraulic tightening-arrangement may be applied to a jaw chuck as shown diagrammatically in Fig. 6, or to a tool-holder.