Patent GB-758412-A (GB)
Title: Improvements in ball point pens
IPC: B43K24/08
Filed: 1954-08-04
Abstract: 758.412. Reservoir pens. PARKER PEN CO. Aug. 4, 1954 [Dec. 29, 1953], No. 22673/54. Class 146(3) In a ball-point pen of the kind wherein the writing unit can rotate and reciprocate within the casing, and can be projected from, or retracted within the casing and in so doing is rotated step-bystep in one direction, the mechanism effecting such operations is actuated by a manually-operable reciprocating element which is restrained against rotation. The writing, unit attains the projected position two or more times in the course of each rotation: As shown in Figs. 1 and 5, the outer casing comprises a main section 2 and a rear section 4 which is secured, as by soldering and deformation, to a tubular inner portion 27 having screw-thread engagement with the section 2. The writing unit 7 is slidable and rotatable in the casing, and the reservoir 10 is secured by crimping at 26 to a cam body 20 which is hollow to allow air to reach the ink in the reservoir, and is rotatably and slidably disposed in the portion 27. A reduced tubular extension 33 of the portion 27 serves as a guide for a tubular plunger 34 having a push button 35, and a return spring 38 is arranged between shoulders on the plunger 34 and portion 27. Diametrically opposed fingers 43, 44 on the plunger 34 pass through slots in the shoulder 40 of the portion 27 to pass inside the latter and are guided for sliding therein by fixed stops such as 46 struck out from the portion 27. The ends of the fingers 43, 44 are oppositely inclined and are adapted to engage one of two pairs of cam surfaces on the cam 20. These cam surfaces, such as 52, 53, 54, are all inclined in the same direction, and when a pair is engaged by the fingers 43, 44 on depressing the button 35, they slide forward the writing unit 7 against the action of a spring 16, and also cause the unidirectional rotation of the cam and unit 7. With the push button 35 in inoperative position, the stops 46 engage-two opposed cam surfaces; if these surfaces are deeply cut, the writing unit 7 is wholly within the casing, but if they are shallow, then the unit 7 is held projected in the writing position. The unit 7 is arranged to rotate in four equal steps of 45 degrees each successive time it is advanced and retained in writing position, so that unequal wear on the seat of the writing ball is minimized Two modifications are described and shown. In one (Figs. 16-22) the cam surfaces extend radially inwards to a central bore, the plunger is solid with a central spigot and two opposed wing portions shaped to engage the cam surfaces, and the stops which engage the cam surfaces in the projected and retracted position of the witting unit are -formed inside a tubular guide within which the plunger slides. In the other form shown in Fig. 23, a sleeve section 128 is screwthreaded on the main casing 102, the real section 104 is secured to this sleeve, and a tubular extension 127 of the sleeve is of such a length that the plunger 134 is within the sleeve even in inoperative position. The forward end of the plunger has two opposed slots and corresponding fingers, the slots always engaging projections on the inside of the sleeve 128, and the fingers being adapted to engage camming surfaces 150 on a cam body 120. The cam 120 has an extension 149 telescoped in the plunger 134, so that the cam plunger and sleeve 128 are always held in alignment. There is a floating connection 124<SP>1</SP> between the cam body 120 and the ink reservoir 110 to allow for any misalignment of the writing unit 107. Some of the parts may be moulded from plastic material such as nylon.