Patent GB-808523-A (GB)
Title: Improvements in retractable writing instruments
IPC: B43K24/03
Filed: 1956-07-04
Abstract: 808,523. Reservoir pens. PARKER PEN CO. July 4, 1956 [July 5, 1955(3); July 28, 1955; March 19, 1956], No. 20752/56. Class 146(3) In a pen, such as a ball-point pen, wherein the writing unit can reciprocate in the barrel between a projected position and a retracted position, the retraction holding means includes co-operating magnetic elements, at least one of which is a permanent magnet, the unit being movable from retracted to projected position by inertia, and complementary facing parts on the barrel and the unit are Provided for non-yieldably but releasably retaining the unit in projected or writing position. In Fig. 1, a ball-point writing unit 20 is slidably housed in a two-part barrel 14, 16, and is pressed by a weak spring arm 44, so that a metal plug 38 on the end of the unit engages a shoulder 42 formed on the inside of the bore of the barrel part 16: the unit 20 is thus held Unyieldingly in projected writing position. To retract the unit 20, the barrel is either tapped or shaken to dislodge the plug 38 from the shoulder 42, whereupon a permanent magnet 40 attracts the unit within the barrel. Instead of the spring arm 44, the pocket clip 48 may be extended and bent to engage the unit 20 through an aperture in the bariel. Fig. 9 shows an extended pocket clip 66 engaging an element 74 which is flexible and non-springy and mounted in the bore of the barrel. A portion 78 extends into an opening 80 in the barrel where it can be engaged by the pocket clip 66 to move the upper end of the writing unit, to engage tthe shoulder 64 in the barrel, against the action of a spring arm 70. When the clip 66 is released, the spring 70 moves the unit away from the shoulder 64, and the unit is retracted by the permanent magnet 62. In a modification of Fig. 9, the spring 70 and element 74 are omitted, and the pocket clip includes a permanent magnet bearing against the end of the writing unit which is of metal, whereupon the outward flexing of the clip pulls the unit out of engagement with the shoulder in the barrel, and the unit is then retracted by the upper magnet, as before. In the construction shown in Fig. 14, a slidable follower unit 242, which may be the permanent magnet, is shaped at 246 to engage a metal plug 240 in the end of the writing unit 220 to wedge the latter to one side to engage a shoulder 236 in the barrel when the unit is in writing position. To retract the writing unit 220, the pen is inverted so that the follower 242 falls downwardly to abut a. metal plug 244; similarly, the writing unit 220 falls by gravity, aided by the magnetic attraction between the elements 240 and 242. The unit 220 is projected by shaking the pen in a forward direction. The shapes of the plug 240 and the wedging face 246 of the follower 242 may be varied. In another form (Fig. 21, not shown), the writing .unit is not held in writing position by a shoulder on the inside of .the barrel, but is held in that position by the engagement of the end of a leaf-spring with one of a number of shoulders on a metal plug secured in the end of the writing unit. The leaf spring is normally biased away from the plug, and is urged towards the latter by a pocket clip projecting inwardly of the barrel through an aperture therein. When the pocket clip is released, an upper magnet (similar to that shown in Fig. 1) draws the unit within the barrel. In a further construction (Fig. 25, not shown), there is an upper magnet, and a metal plug in the end of the writting unit, but no positive means for ensuring that the metal plug engages the shoulder provided within the barrel when the unit is in projected writing position: this means that the pen must be held for writing in one position only, i.e.; with the shoulder side of the barrel downward, and this position may be indicated by the position of the pocket clip.