Patent GB-191111639-A (GB)
Title: Improvements in Pencil Sharpening Machines.
Inventor: WEBSTER EDGAR PARKER
IPC: B43L23/04
Filed: 1911-05-13
Granted: 1912-01-11
Abstract: 11,639. Webster, E. P. May 13. Pencil - sharpeners. - In pencil - sharpening machines of the type in which both the cutter and the pencil rotate, and in which the pencil rests in a conical bushing having an opening through which the cutter operates, the cutter and pencil continuously rotate in opposite directions at their point of contact, and the pencil is held so as to be fed automatically by gravity on to the sharpening-device, and may be sharpened either with a round or a chisel-shaped point. The main shaft 33, Fig. 1, supported by the frame 3 in a casing 2, is rotated by the handle 34 and carries a bevel-wheel 35 which meshes with a larger bevel-wheel 36. Attached to the wheel 36 are an annular ring 37, having teeth 40 on its inner periphery so as to drive the cutter 10 through a pinion 11, and a hub 38, on the upper reduced portion of which is mounted a cap 44. A projection on the rim of the cap 44 engages a vertical slot a in a loose bevel-based sleeve 45, so that this sleeve rotates with the hub 38 and cap 44, but is free to move vertically. Inside the sleeve 45 is a thimble 47 having an enlarged lower portion which is pressed downwardly by a spring 53, and which carries internally a ring 54 supporting oval clamping-pieces 56, Fig. 2. The upper end of the thimble has a bevelled tooth 49 engaging a bevelled notch 50 connected with the sleeve 45, and finger-pieces 48, 52 are connected to the sleeve and thimble respectively. If the fingerpieces are pressed together, the bevelled tooth 49 rides upwardly along the notch 50, and so elevates the thimble 47 against the pressure of the spring 53; at the same time, the clamps 56 part so as to allow a pencil to be inserted into the conical bushing 13. When the finger-pieces are released, the spring 53 causes the thimble 47 to return to its initial position, and the clamps 56 are guided by the bevelled base 46 to grip the pencil. Screwing into the lower part of the bushing 13 is a screw bolt 26, which passes down the centre of a gauge pin 15, and the head 28 of the bolt is pressed by a spring 29 inserted in the widened bore 19 of the gauge pin. The gauge pin passes through a fixed thimble 16 having two notches 21, 22 of different depths, in which engages a tooth 24 on a collar 23 rotatably secured to the gauge pin. The gauge pin is normally elevated by a spring 20 acting on the head 17 of the pin which supports the pencil point, and, by allowing the tooth 24 to engage one or other of the notches 21, 22, the head 17 is so adjusted that the pencil may be sharpened to two different degrees. In order to produce chisel - shaped points, it is arranged that the cutter and pencil may be brought into closer proximity twice during each revolution of the pencil, and accordingly the bevel-wheel 36 has twice as many teeth as the wheel 35. In the method as illustrated in Fig. 1, the pencil is adapted to approach the cutter, and, in order to effect this, the shaft 33 is eccentrically bored at 60, and the end 62 of a rod 64 engages when required a recess 63 in the bushing 13, so that the bushing moves up and down as the shaft 33 rotates. This action only occurs when a pin 68 on the rod 64 is allowed to slip into a notch 69 in the shaft, thus permitting the rod 64 to be advanced by a spring 67; otherwise the pencils are sharpened with a round point. In a modification, as shown in Fig. 4, the cutter 10 is arranged to approach the pencil. An L-shaped lever 70 slidable on base-plates 2 has a bevelled lug 71 adapted to be engaged by a bevelled lug 72 carried by the gear 35. As the shaft 33 revolves, the engaging lugs 71, 72 force the lever 70 towards the casing 3, thus bringing the cutter nearer the pencil, and a spring 73 secured to the base-plate subsequently retracts the lever to its normal position. In both modifications, a screw 57 fixed in the frame 3 slides in a slot in the bushing 13 so as to prevent the bushing from rotating, and the bushing is cut away at the opposite side to allow the cutter to operate on the pencil.