GB880529A - Improvements in or relating to writing instruments - Google Patents

Abstract

880,529. Writing instruments. TALLON Ltd., and ARENGO, C. G. April 14, 1959 [April 25 1958], No. 13269/58. Class 146(3) A retractable writing instrument, e.g. a ball point pen, comprises a plunger 19 which is movable with the writing unit 12 and which projects from the rear end of the barrel, a spring 27 which urges the writing unit 12 towards retracted position, a push-button 28 slidable laterally in the barrel, interengaging means on the push-button and on the plunger which when engaged retain the writing unit in the projected position, and a second spring 34 which urges the push-button outwards in relation to the barrel. The plunger 19 has a spigot at its forward end which is a friction fit in the rear end of the writing unit 12, and is of rectangular cross-section so as to slide non-rotatably in a correspondingly shaped bore at the rear end of the barrel. The spring 27 is seated at its forward end on a bush 26 fitted in the barrel and at its rear end on a collar 25 on the plunger. Shoulders (not shown) on the plunger engage other shoulders on the interior of the barrel to limit rearward movement thereof. The plunger 19 is slotted at 33, the width of the slot being enlarged at 36 so as to form longitudinal shoulders 37 in the slot. The rear ends of the shoulders 37 are recessed at 39. The push button 28 is radially slidable in a lateral slot 29 in the barrel and has an inner portion which is slidable in the slot 33 in the plunger 19, ears 31 on the push button being engaged in the enlarged portion 36 of the slot 33. Projections 32 on the outer face of the push-button 28 limit inward depression of the button. The spring 34 is a leaf spring attached to the plunger 19 and has a rearwardly extending arm which bears on an inclined face 35 of the push-button 28 to urge the latter outwards. In the retracted position of the writing unit, as shown, the ears 31 on the push button abut against the longitudinal shoulders 37 in the plunger slot 33. When the plunger is depressed it rides over the push button until the ears 31 are snapped into the recesses 39 by the spring 34, whereby the plunger and writing unit are latched in the projected position. The button 28 is pressed inwards to disengage the ears 31 from the recesses 39 and allow retraction of the plunger and writing unit by the spring 27.