Dec. 17, 1946. R. c. MAGEE SLIDE-RULE PENCIL 2,412,820 Filed March 9, 1945 ¿cauti C. 4:42.70., JNVENTOR. Patented Dec. 17, 1946 2,412,820 UNITED STATES PATENT GFFICE 2,412,820 SLIDE-RULE PENCIL Robert C. Magee, Dayton, Ohio Application March 9, 1945, Serial No. 581,886 5 Claims. (Cl. 235-70) 1 2 My invention relates to devices which are usable immovably together so that when the device is both as a pencil and as a slide-rule and which used as a pencil there can be no relative move may be conveniently carried around in the pock ment between these parts. Such locking means may comprise a spring ñnger I9 of which one end et, the same as a pencil or fountain pen; and its object is to provide Certain improvements there is secured to the cursor and the other end car ries a locking lug or pin 2li. The tubular slide I5 is provided at its upper end with an annular in and more particularly to provide means where by the movable parts of such a device may be easily and quickly locked together so as to be shoulder 2i which limits the movement of the cursor toward that end, as shown in Fig. 2, and, near said shoulder, with a hole 22 which, when the cursor is in the position shown in that fig ure, registers with said locking lug or pin; and the pencil has a recess 23 with which the hole 22 also registers when the parts are in the po sition shown in Fig. 2. Through means, such as held against relative movement when the device is used as a pencil. In the drawing, Fig. l is a view in side elevation of a device‘em bodying my invention; Fig. 2 is a view thereof in longitudinal section on a larger scale; and Fig. 3 is a view in transverse section taken on a plane indicated by the line 3-3 in Fig. 2. a thumb-slide 24, movable upon the cursor and having a projection 25 which rides along the spring finger I9 when the thumb-slide is moved The pencil il! may be of any type or indeed forward, said locking lug or pin may be caused, any writing implement whatever; as shown here in, it is a lead reñllable pencil having a maga 550 when the parts are in the position shown in Fig. 2, to pass through the hole 22 in the tubular zine I i for the storage of new leads, which maga slide I5 and into the recess 23 of the pencil, thus zine is closed by a stopper I2 on the end of which locking the curso-1', tubular slide and pencil im an eraser I3 may be provided. The pencil, as movably together; and when the thumb-slide is shown, is also preferably provided with a raised portion I4 (Fig. 3) on its periphery for a pur 25 retracted to its rearward position, that is the position shown in Fig. 2, the spring linger I9 pose presently to be referred to. Closely ñtted causes the locking pin 2!! to be withdrawn from around the pencil and movable longitudinally its locking position so as to permit the free move therewith is a tubulal` member or slide I5 which ment again of the tubular-slide I5 along the pen may, if desired, extend practically the entire cil and of the cursor along both the tubular-slide length of the pencil and which has a longitudinal and pencil. The tubular-slide may be provided slot I6 through which the surface of the pencil with a longitudinal groove 25 in which the sprirg is visible. The visible portion of the pencil is finger I9 rides to prevent the cursor from turning marked lengthwise with a Scale (as indicated in around said slide, whereby the transparent por Fig. l) suitably graduated to serve as one of the scales of a slide-rule. There may also be marked - i on the tubular slide along one or both of the and slide respectively. Finally, a pocket clip 21 may be secured to the edges of the longitudinal slot IS thereof, grad uations appropriate for use as scales of a slide rule in cooperation with the scale marked on the pencil. The raised portion I it of the pencil projects into the slot IS and its purpose is to pre vent relative rotary movement between the tubu lar slide and the pencil so as to keep the scale on the pencil in register at al1 times with said slot. Said raised portion may have, and prefer ably has, the form of a longitudinal ridge extend ing the full length of the pencil and exactly ñt ting said slot; and in such case the scale car ried by the pencil is marked upon this ridge. tio-n of the cursor is maintained at all times in proper relation to the scales marked on the pencil cursor as shown, whereby said clip is held im movable on the device when the cursor is locked in position thereon. Thus, through a single move ment of the thumb-slide the pocket-clip, cursor and tubular-slide are all three immovably ñxed i Movably embracing the tubular slide lâ is a ‘i cursor having a transparent portion il marked with an index-line or lines it and through which the respective scales of the tubular slide and pencil are visible. Said cursor is provided with means to lock it and the pencil and tubular-slide ~ ' to the pencil. I claim as my invention: l. In a device of the class described, a pencil having a scale marked lengthwise thereon, a tu bular-slide movable along the pencil and having a longitudinal slot registering with the scale on the pencil, a scale marked along an edge of the slot of the tubular-slide to cooperate with the scale on the pencil, and a cursor movably ern bracing the tubular-slide and having a trans parent portion marked with an index line, in combination with means carried by the cursor to 2,412,820 - 3 lock the cursor tubular-slide and pencil immov ably together when the device is used as a pencil. 2. The combination defined in claim 1 and fur ther characterized by this: that the locking means carried by the cursor comprises a spring `finger having a locking lug normally held by the finger in its unlocking position, and means cooperative with the finger to move the lug into its locking position. - . , 4. The combination defined in claim 1 and fur ther characterized by this: that the tubular-slide has a shoulder at its upper end to limit the move ment of the cursor toward that end, that the pencil has a recess and the tubular-slide a hole adapted to register with said recess, and that the locking means carried by the cursor has a locking pin which registers with the hole in the tubular slide when the cursor is in its limiting position 3. The combination deñned in claim 1 and fur 10 on the upper end of the tubular-slide. ther characterized by this: that the pencil has a 5. The combination deñned in claim 1 and fur recess and the tubular-slide a hole adapted to ther characterized by this: that a pocket clip is register with said recess, and that the locking fixed to the cursor whereby the clip is held im means carried by the cursor has a locking pin movably to the pencil when the cursor is locked which is movable into and out of the recess and 15 to the pencil and tubular-slide. through the hole in the tubulareslide. ROBERT C. MAGEE.