GB569745A - Improvements in or relating to mechanically operated pencils - Google Patents

Abstract

569,745. Pencil holders. WEINBERGER, Ltd., H., and WEINBERGER, G. H. Nov. 29, 1943, No. 19900. [Class 146 (iii)] Relates to a propelling pencil of the kind in which the lead 4 is fed by a rod 3 operated by a projection thereon engaging a helical slot 5a in a rotary member 5. The member 5 carries a knurled sleeve 7 abutting against the outer end of a recess 1a in the point section 1 spaced from the end of the member 5. The barrel 9 is a sufficiently tight fit on the sleeve so that when rotated it turns both the sleeve 7 and the member 5. A hub 2 fixed to the section 1 is situated between the member 5 and the rod 3 and has a longitudinal slot 2a through which passes a projection 3a on the outer end of the rod 3. The projection 3a is formed with a helical part 3b adapted to lie within the groove 5a, the part 3b forming a spring. When the rod 3 is moved to its extreme forward position, the part 3b leaves the groove 5a and becomes compressed in the recess la so that further turning of the barrel 9 causes no over-straining of the mechanism. The lead 4 is held in a holder 6 which is a friction-tight fit on the rod 3 and abuts against a recess 1b in the section 1 in its outer extreme position so that further rotation of the barrel moves the rod 3 relatively thereto to expel the lead. On the return movement of the rod 3, the parts 3, 6 move together until the holder 6 abuts against an obstruction 13 on the hub 2 whereupon the rod 3 moves relatively thereto until it is restored to its normal position with the projection 3a engaging the inner end of the slot 6a. In order that the part 3b may be utilised to prevent strain on the mechanism during the withdrawal movement of the holder 6 the modified construction of the rear end shown in Fig. 5 is employed. The sleeve 7 is extended beyond the rear end of the member 5 and is closed by a disc 10 secured to the end of the hub 2 by a screw 11. At the inner end of its travel, the part 3b moves out of the groove 5a into the recess between the end of the member 5 and the disc 10 and is compressed as before. In this form, the slot 6a in the holder 6 extends to the rear end of the holder. The holder 6 is retracted by the rod 3 until its end abuts against the disc 10 whereupon further rotation of the barrel 9 causes relative movement between the rod 3 and the holder 6 to restore the latter to its normal position.