GB844664A - Retractable-extendable writing instrument - Google Patents

Abstract

844,664. Writing instruments. FERBER CORPORATION. April 15, 1958, No. 11974/58. Class 146(3). A retractable writing instrument e.g. a ballpoint pen, operated by a press-button actuator, has detent means adapted alternatively to maintain the writing tip in its operative position or to permit it to return under the action of spring means to its retracted position, the detent means comprising alternate long and short helical grooves provided in a cylindrical surface of a part of the instrument and a resilient element engaging into one of the said grooves, whereby operation of the actuator causes relative axial and rotational movement between the resilient element and the grooves so that after each depression of the actuator against the action of the spring means the resilient element will engage into the next adjacent groove. The pressbutton actuator 19 is slidable and rotatable in the rear end of the barrel and has a cylindrical portion 38 having a short blind bore at its front end to receive the rear end of a ball-point writing unit 18. The cylindrical portion 38 is formed with alternate long and short helical grooves 41, 42, 41a, 42a (shown in developed condition in Fig. 9), one of which is engaged by a resilient tongue 35 forming a part of the pocket clip 30 and extending inside the barrel. The writing unit 18 is rearwardly biased by a spring 21 so that when the tongue 35 engages the lower end of a long groove 41 or 41a. i.e. position 2 or 6, Fig. 9, the writing point 25 is retracted within the barrel thereby. Depression of the actuator 19 causes the tongue 35 to ride out of the groove 41 or 41a and take up a position (3 or 7, Fig. 9), at the upper end of one of the short grooves. When pressure on the actuator is released it is carried back with the writing unit by the spring 21 until the tongue 35 abuts against the lower end of one of the short grooves, the actuator and writing unit being partially rotated by the camming action of the tongue 35 with the groove and the writing point 25 being then projected from the barrel. The point is retracted by a further depression of the plunger which causes the tongue 35 to re-enter one of the long grooves. To help the tongue 35 to ride out of the grooves the upper, inclined edge of each groove may be bevelled and vertical edges may be provided at the lower ends of the longer grooves. In a modification, two tongues similar to 35 are punched out of a sleeve inserted in the rear end of the barrel and engage diametrically opposed grooves in the cylindrical portion 38 of the actuator 19.