ES361389A1 - Writing instrument - Google Patents

Abstract

In a multiple, retractable writing instrument having a single push button 5 for rotating and sliding a drum 3 housing a plurality of cartridges, only a single compression spring 11 is provided for the projecting mechanism, which spring acts against the drum 3 biasing it rearwardly. The drum 3, (Fig. 10) has a first chamber 3a for slidable receiving the rear ends of the cartridges so that they are in tangential contact one with another. A cylindrical bore defines a second chamber 3b in the drum, an abutment or shoulder being formed between the two chambers. Into the rear end of each cartridge is inserted a cylindrical shank 12a of a sector shaped guide 12 provided with a shoulder 12c, which abuts the shoulder in the drum 3. Fastened to the push button 5 (Fig. 9 is a rod 4 which has one or several fingers (4a), which co-operate with notches (3d) in the top edge of the drum 3. With the drum 3 biased against the fingers (4a) by the spring 11, rotation of the push button 5 brings a selected cartridge into alignment with the eccentric opening 1a provided in the instrument barrel 1. A washer 7 fixed in the barrel also has notches (7a) which co-operate with the top edges of fingers (4a), thereby defining each angular position of the drum 3 to align each cartridge. An eccentric pusher 6 in which the rod 4 rotates, is fixed angularly with respect to the barrel and the washer 7, but slides through an eccentric hole (76) in the washer to contact the rear of the guide 12 of the selected cartridge when the pushbutton is depressed. When the selected cartridge is projected by depressing the button 5 (Fig. 11), the drum slides forward on the remaining non-selected cartridges which abut a shoulder 1b in the barrel 1. The cartridge is retained in the projected position by a known type of push-button actuated mechanism until the button 5 is again depressed and the drum 3 is released to be moved back by the spring 11. In an alternative embodiment (Figs. 14 and 15) the drum 3 is eliminated and the spring 11 acts as a single holding means for the cartridges which are bunched therein. The spring 11 is compressed between the shoulder 1c in the barrel and the shoulders 12c of the guides 12. Rotary movement is achieved with the fingers 4a inserted into the grooves (12d) formed between the guides 12.