GB147865A - Improvements in dies or moulds used for duplicating gramophone records and for like purposes - Google Patents

Abstract

147,865. Columbia Graphophone Manufacturing Co., (Assignees of Davenport, G. E.). Aug. 14, 1916, [Convention date]. Embossing.-Means for heating and cooling a die consists of a plurality of passages in proximity to the surface of the die and means by which a heating fluid or a cooling fluid may be passed through all of said paths concurrently. Fig. 1 is a section of the press, Fig. 2, of the die or matrix holder, and Fig. 3 a section on the line 5-5 of Fig. 2. The lower die 37, Fig. 1, is mounted in a piston 33, and the upper die 49 is carried by a head 48. The upper face of the die has a shallow recess 50 to receive the matrix and outside this a deeper annular recess 53, the walls of which are screw-threaded. A locking-ring 55 screws into this recess and has a flange 56 projecting over the edge of the matrix. On its under face the die has a wide annular recess 58 into which screws a plate 62. The die plate is formed with a number of concentric spiral grooves 61, preferably two series, merging into each other at the centre, where there is a passage 63 connected to an outlet pipe, but ending at diametricallyopposite portions of the die where are passages 64 and 65 connected to steam and cold water inlet pipes 66 and 67. Steam is passed through to keep the matrix soft until pressure is applied, whereupon the steam is shut off and cold water is passed through. The Specification as open to inspection under Sect. 91 (3) (a) describes also the construction of the hydraulic press shown in Fig. 1. The base plate 12 is bored out to provide the cylinder 13 and supports three standards 14 which serve as guides for the piston 33 and buck-head 38. Between the standards are two locking arms 16 at each side of the machine, with inwardly-projecting heads 17. They are pivotally mounted on. transverse bolts 18 and extend below in arms 19 which are connected bv means of links 24 to disks 23 mounted on a shaft in a bracket 20. The connexions are at opposite ends of a diameter of the disk 23 and a handle is provided for turning the disk in either direction. Liquid under pressure is admitted by a duct 32. The buck-head 38 has a rearward extension pivotally mounted on a bracket extending upward from the base and connected by means of two links to an arm 43 mounted on the shaft 44. At the extremities of the shaft 44 are arms 46 carrying balance weights which normally keep the buck-head in a raised position. The buck-head has a handle 48 for lowering it. This subject-matter does not appear in the text of the Specification as accepted.