US2274311A

US2274311A - Mechanical pencil

Info

Publication number: US2274311A
Application number: US391855A
Authority: US
Inventors: Charles E Wehn
Original assignee: LISTO PENCIL CORP
Current assignee: LISTO PENCIL Corp
Priority date: 1941-05-05
Filing date: 1941-05-05
Publication date: 1942-02-24
Anticipated expiration: 1959-02-24

Description

Feb. 24, 1942. c. E. WEHN 2,274,311

MECHANICAL PENCIL Filed May 5, 1941 FJE-L- Y IN V EN TOR. CmqeLEs E. WEHN.-

BY Mr 7356x4208 ArTOENEX Patented Feb. 24, 1942 UNITED STATES PATENT OFFICE 2,214,311 'MECHANICAL PENCIL Charles E. -Wehn, Alameda, Calif., assignor to Listo Pencil Corporation, Alameda, Callie a corporation of California Application May 5, 1941, Serial No. 391,855

8 Claims. (Cl. 120-18) ble sleeve and in which the sleeve containing the lead or crayon is insertable in the head or point of the pencil; to provide a pusher bar which is adapted to enter the sleeve for the purpose of propelling or advancing the lead or crayon as the point or outer end thereof is being worn away; to provide means for frictionally retaining the sleeve in the point of the pencil as the lead or crayon is being advanced; to provide means for ejecting the sleeve from the point of the pencil, to permit it to be refilled and then replaced in the head when the lead or crayon first placed therein has been used up; to provide a pencil point or head which is adapted to receive a sleeve and lead which are rectangular in cross section, or of any other cross-sectional shape which is not circular; to provide a pusher bar which is advanced or retracted by rotation ofv either the pencil point or the barrel of the pencil; and further, to provide a pusher bar which has a cross-sectional shape similar to that of the lead receiving sleeve, said shape being such that there can be no rotation between the pusher bar and sleeve as the bar is being advanced through the sleeve. I

The invention is shown by way of illustration in the accompanying drawing, in which Fig. 1 is a central vertical longitudinal section of the pencil; I

Fig. 2 is a perspective view of the nut;

Fig. 3 is a cross section taken on line IH-III of Fig. 1; V

Fig. 4 is a cross section taken on line IV-IV of Fig. 1;

Fig. 5 is a perspective view of the pusher bar;

Fig. 6 is a perspective view of the interlocking ring; and

Fig. 7 is a perspective view of the lead or crayon carrying sleeve.

Referring to the drawing in detail, and particularly to Fig. 1, A indicates the barrel section of a pencil, B the point or lead receiving section,

gitudinal separation, and this is accomplished in the following manner.

Formed on the inner end of the point B is an extended section 2 which is circular in cross section, and so is the interior of the barrel. Formed on the outer surface of the extension 2 is an annular groove 3, and formed within the barrel in alignment therewith is an annular groove 4. Adapted to be received in the groove 3 is a split ring 5 (see Figs..1 and 6). Thisring is placed in the groove 3 and compressed, and the extensionand ring are then' pushed into the open end of the barrel section A, and when the rooves 3 and l register the ring 5 will expand and will then permanently secure the point section B against endwise removal from the barrel section A, but it will permit free rotation of either section.

Formed in the point section B is a lead receiving passage which in this instance is rectangular in cross section, and adapted to be in- I serted in said passage is a rectangular sleeve 5 (see Figs. 1 and '7) which is adapted to contain a lead or crayon such as indicated at ,1. The sleeve has a spring detent formed in one surface thereof, as indicated at 8, and this is adapted to spring outwardly and enter one or another of a pair of recesses 9 formed in opposite faces of the passage in the point.

Secured within the barrel section is a nut 10 (see Figs. 1 and 2) and adapted to extend therethrough is a pusher bar which is bestshown in Fig. 5. The major portion of this bar is flattened on opposite sides, as indicated at H, but the rear or inner end remains round in cross section as shown at l2, so as to form a pair of shoulders "-44. The bar is of such a length that when its inner end engages the closed end ii of the barrel the opposite end will enter the lead receiving sleeve 6. 1

An important feature of the present invention is the fact that the bar, together with the sleeve, is of a non-circular shape, as rotation between the two must not be permitted. The shape shown in this instance is rectangular, as the bar which enters the sleeve is rectangular and so is the sleeve; in fact the lead receiving passage must also be rectangular, as it is thereby possible to impart or transmit longitudinal movement to the bar to advance the lead 1 to writing position, by rotation of either the point B or the barrel A. The pusher bar is threaded from end to end, and thus is in threaded engagement with the nut; hence if the barrel is rotated in a certain direction the nut will also be rotated; and as the barrel is held against rotation with relation to the point, longitudinal movement will be transmitted to the bar and the lead will be advanced to writing position when worn away. Similarly, if the barrel is held and the point B rotated, rotary motion will be transmitted to the bar, through means of the sleeve, and as the bar rotates within the nut, longitudinal movement will again be transmitted. This is very important, as it simplifies the actuating mechanism and reduces it to an absolute minimum number of parts; in fact it may be said that the actuating mechanism consists of only two parts, to wit, the nut Ill and the pusher bar which extends therethrough.

In actual operation the lead, crayon or whatever material is to be employed, is inserted in the sleeve and the sleeve, together with the lead, is then pushed into the point B from the front end thereof, and when it is fully inserted the spring detent will spring outwardly into one or another of the pockets 9, and the sleeve will thus be frictionally secured against endwise removal. Whenever the lead wears away it may be advanced as previously described, by merely rotating either the barrel or the point of the pencil. The sleeve will not be advanced under that particular condition, as it is frictionally retained against longitudinal movement by the spring detent 8. On the other hand, when the lead has been completely consumed, or in other words when the sleeve is empty, continued rotation of either the head or the barrel will advance the pusher bar to a point where the shoulders I will engage the inner end of the sleeve, and the sleeve will then be forcibly ejected; that is, its forward end will be pushed outwardly from the point of the pencil a sufficient distance to permit it to be grasped and pulled out. A new lead or crayon may then be placed in the sleeve, and it may be reinserted when the bar has been returned to its fully re-- tracted position shown in Fig. 1 by reverse rotation of the barrel or point. 7

A number of mechanical pencils have been constructed, for handling colored leads, crayons and similar substances, but they have proven a failure for the simple reason that a certain amount of fatty substance is usually contained in leads of this character, and this has a tendency to adhere to the inner surface of the lead receiving passage ofthe pencil; This deposit builds up to such an extent in a comparatively short time that it is almost impossible to force the lead or crayon through, and the result is that the propelling mechanism is subjected to excessive strain and wear, and furthermore, the crayon or lead is crushed and broken. In the present instance the sleeve 6 is split longitudinally, as shown at 6a, to give it a certain amount of circumferential resiliency. When the pencil here shown is used for colored leads, crayons or the like, they are inserted in the sleeve; the sleeve itself will obviously not clog the lead receiving passage, but the interior of the sleeve may gather a deposit, and when this occurs the sleeve may be renewed. Thus when colored leads, crayons or the like are sold in connection with a pencil of this character, one or more extra sleeves will also be supplied, so that a dirty or clogged sleeve may be thrown away and a new one substituted therefor. Where ordinary lead is used, the rectangular shape is particularly applicable, for instance, as a carpenter's pencil or for drafting purposes, and in that case the sleeve 6 may be been more or less specifically described and illus-- trated, I wish it understood that changes may be resorted to within the scope of the appended claims, and that the materials and finish of the several parts employed may be such as the experience of the manufacturer or varying conditions or use may demand.

Having thus described and illustrated my invention, what I claim and desire to secure by Letters Patent is:

1. In a pencil, a point and a barrel section independently rotatable with relation to each other, a lead receiving passage formed in the point, a nut secured within the barrel, and a pusher bar within the barrel and extending through the nut and into the lead receiving passage, said bar having threaded engagement with the nut, and said bar and the lead'receiving passage being non-circular in cross section, whereby rotation of either the point or the barrel will impart longitudinal movement to the bar to advance a lead to writing position when placed in the lead receiving passage.

2. In a pencil having a point and a barrel section, means securing the point against endwise removal from the barrel but permitting rotation of either, a lead receiving passage formed in the point,.a nut secured within the barrel, and a pusher bar within the barrel and extending through the nut and into the lead receiving passage, said bar having threaded engagement with the nut, and said bar and the lead receiving passage being non-circular in cross section, whereby rotation of either the point or the barrel will impart longitudinal movement to the bar to advance a lead to writing position when placed in the lead receiving passage.

3. In a pencil having a lead receiving passage formed therein, a sleeve containing a lead insertable in said passage, manually operable means for advancing the lead through the sleeve to a writing position, means for retaining the sleeve against removal while the lead is being advanced, and means for ejecting the sleeve from the passage when the lead has been consumed.

4. In a pencil having a lead receiving passage formed therein, a sleeve containing a lead insertable in said passage, manually operable means for advancing the lead through the sleeve to a writing position, friction-actuated means for retaining the sleeve against removal while the lead is being advanced, and means for ejecting the sleeve from the passage when the lead has been consumed.

5. In a pencil having a lead receiving passage formed therein, a sleeve containing a lead insertable in said passage, manually operable means for advancing the lead through the sleeve to a writing position, a spring detent retaining the sleeve against removal while the lead is being advanced, and means for ejecting the sleeve from the passage when the lead has been consumed.

6. In a pencil having a barrel and a point section, means securing the point against endwise removal from the barrel but permitting rotation of either, a lead receiving passage formed in the point, a sleeve containing a lead insertable in said passage, a. pusher bar within the barrel and extending into the sleeve when the sleeve is inserted in the point section, said bar and sleeve having a non-circular cross section to prevent rotation between the bar, the sleeve and the point section, means actuated by rotation of either the point or the barrel for imparting longitudinal movement to the bar to advance the lead to a writing position, means for securing the sleeve within the point while the lead is being advanced, and means for ejecting the sleeve when the lead has been consumed.

7. In a pencil having a barrel and a point section, means securing the point against endwise removal from the barrel but permittingrotation of either, a lead receiving passage formed in the point, a sleeve containing a lead insertable in said passage, 9. pusher bar within the barrel and extending into the sleeve when the sleeve is inserted inrthe point section, said bar and sleeve having a non-circular cross section to prevent rotation between the bar, the sleeve and the point section, means actuated by rotation of either the point or the barrel for imparting longitudinal movement to the bar to advance the lead to a writing position, means for securing the sleeve within the point while the lead is being advanced,

and means on the bar for ejecting the sleeve when the lead has been consumed.

8. In a pencil having a barrel and a point section, means securing the point against endwise removal from the barrel but permitting rotation of either, a lead receiving passage formed in the point, a sleeve containing a lead insertable in said passage, a pusher bar within the barrel and extending into the sleeve when the sleeve is inserted in the point section, said bar and sleeve having a non-circular cross section to prevent rotation between the bar, the sleeve and the point section, a thread on the bar, a nut within the barrel through which the bar extends, said nut being secured against rotation within the barrel, whereby rotation of either the barrel or the point will transmit longitudinal movement to the bar to advance the lead through the sleeve to a, writing position, means for securing the sleeve against removal while the lead is being advanced, and means on the bar for ejecting the sleeve when the lead has been consumed.

CHARLES E. WEHN.