GB930464A - Improvements in writing instruments - Google Patents

Abstract

930,464. Writing instruments. ROLL TIP (ENGLAND) Ltd. April 5, 1961 [April 5, 1960], No. 12046/60. Class 146 (3). A retractible writing instrument, e.g. a ballpoint pen, comprises in its projecting mechanism a rotatable member 21 which is rotated step-bystep in response to successive depressions of an operating plunger 17 and has marked thereon around the periphery a series of numbers or characters which upon rotation of the member 21 are brought successively into view through a window 27 in the barrel of the instrument. As shown, the numbers and characters are 1, 2, X and may be used for making random selections in a football pool forecast. The member 21 is rotatably mounted on the rear end of a writing unit 15 and is biased rearwards in the barrel by a spring 24 which grips the writing unit near its rear end. The member 21 has four radially projecting teeth 22 and is of reduced diameter to the rear of the teeth so as to fit rotatably in a bore in the front end of the plunger 17. The plunger 17 is restrained against rotation in the barrel by splines 18 thereon which engage longitudinal grooves in a guide portion 20 mounted in the barrel. Longitudinal ribs in the portion 20 prevent rotation of the member 21 when the writing unit is in retracted position as shown. In order to project the writing unit the operator presses on the plunger 17 and teeth formed at the front end of the plunger, engaging the teeth 22 of the member 21, carry the latter forward until the teeth 22 clear the front ends of the ribs in the portion 20. At this point, owing to co-operating cam surfaces on the teeth the member 21 rotates through # revolution and when pressure on the plunger is subsequently relaxed the spring 24 urges the teeth 22 into engagement with abutments at the forward ends of the ribs whereby the writing unit is latched in projected position. A second depression of the plunger results in a further # revolution of the member 21 which then returns to the position shown wherein the writing unit is retracted. A number or character is visible in the window 27 whether the parts are in their projected or retracted positions. Reference has been directed by the Comptroller to Specification 748,897.