| 摘要 |
810,285. Extrusion-machines for making pencils. CONTE. Aug. 31, 1955 [April 5, 1955], No. 25063/55. Class 87(2). In the manufacture of pencils a pasty composition for forming the lead is extruded through a die 2, Fig. 1. whilst a pasty composition for forming the pencil sheath is extruded through a coaxial die 3, in which it is subjected to a progressively increasing radial compression to form a tubular sheath, surrounding but not contacting the lead emerging from the die 2, and the sheath is united to the lead at the moment at which it is brought to its final section. The sheath composition which may be of wood flour, is fed via a sleeve 1 to the die 3 through bores 5 in the die 2, surrounding the passage 4 for the lead composition. The die 2 projects into and terminates within a conical inlet bore in the die 3. In an alternative die assembly the sleeve 1, Fig. 4, is positioned on the dies 2, 3 by means of box nuts 8, 9, whereby the axial spacing of the dies 2, 3 may be accurately adjusted. In this construction the tubular sheath is formed in a cylindrical chamber 11 in the die 3 and is applied to the lead in the outlet passage 7.
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