US1546516A - Pencil - Google Patents

Description

S. E. SMITH July'Zl, 1925.

PENCIL Filed June 21. 1925 Patented July 21, 1925.

UNITED STATES PATENT OFFICE.

SYDNEY ERNEST SMITH, 0F LGNDON, ENGLAND, ASSIGNOR TO BRIER-LY WOO'DHOUSE AND WALTER BRADLEY SIEIEPHERD,

BOTH OF LONDON, ENGLAND.

' PENCIL.

Application filed June 21, 1923. Serial No. 646,969.

To all whom it may concern:

Be it known that I, SYDNEY Ennns'r SMITH, of 298 Philip Lane. Tottenham, London, N. 15, England, a subject of the King of Great Britain and Ireland, have invented a new or Improved Pencil (for which I have filed application in Great Britain, No. 31,084, the 21st day of November, 1921), of which the following is a specification.

This invention relates to a new or improved pencil, the chief merits of which are claimed to be its simplicity of construction and the fact that it can be operated with 7 one hand only, the mere in'cssure of a finger being su'l'licieut to advance the lead as requi red.

According to the invention, the chief feature of the pencil resides in the lead-propelling device which essentially comprises two members which are so connected together by pawl-and-ratchet or equivalent mechanism that the operatioifbf the device causes one member to be continuously fed forward and thus propel the lead while after the operation, the other member returns to its.

original position, impelled thereto by some such convenient means as a spring. The most convenient form of the device at present known to me comprises a rack member which can slide freely in a tube provided with lugs or the like upon which a springpressed pawl engaging with the rack member is mounted. The rack member at its forward end slides in a friction-tight manner within a second tube which contains the lead which has to be fed forward and this second tube provided with a nose or projection which when the pawl is nearly at the end of its forward movement engages with it and lifts it clear of the rack member which is then free to slide backwards or forwards as suming sutlicient force to be applied to it to overcome its friction-tight fit in the second tube. This last described arrangement is necessary to permit the lead to be pushed up into the nose-piece of the pencil for the purpose of protection when not in use.

The invention will now be described in full detail, and by way of example, with reference to the accompanying drawings, in which Fig. 1 shows a complete pencil partly in section.

Figs. 2 and 3 are detail views on a larger scale showing the parts in operation.

Referring to the drawings, 1 is the barrel of the pencil 2 the nose-piece and 3 the cap,

up and down. The button 5 has a stem 6 guided in a hole drilled axially in the cap 3, the stem being provided with an enlarged head 7 which normally contacts with the shoulder 8 in the cylindrical recess 9 in the cap 3, thus limiting the outward movement of the press-button For convenience, in assembling, the stem 6 is threaded and screwed into the button 5. v

The interior of the barrel 1 is hollow, with two enlarged portions 10 and 11 connected by a narrow neck 12. a bearing for the lead-propelling device, which comprises a tube 13 with one end of which the head 7 contacts, and a rack member 14 which slides freely within the tube 13. At its forward end the rack member 14 is located within a fixed tube 15 in the nosepiece 2, the tube 15 containing the lead 16. The fit of the rack 14 within the tube 15 is friction-tight, that is, it is ordinarily held stationary in any position to which it is moved by friction, but it can be moved to a fresh position either backwards or forwards on sufficient force being applied to overcome the friction. The rack member is preferably formed with a toothed portion square in section and a plain portion of cylindrical section equal in diameter to the inner diameter of the tube 13. This particular construction, however, is not essential, so long as some method is adopted forkeeping the teeth in position to contact with the pawl 17 pivoted between lugs or cheeks 18 formed uponthe tube 13. In the particular arrangement shown, the rack portion of the member 14 is square in section and is guided between the pinched-in ends 19 of the tube 15. The ends 19 may also be slightly resilient so as to aid the frictiontight fit of the rack within the said tube.

The pawl 17 is constantly acted upon by a coiled spring 20 surrounding the tube 13 and pressing against a collar 21 on the tube. The said tube at the forward end is provided with checks 18 partly encircling the tube 15 and pressing against a coiled spring 22 surrounding the latter, the other end of The latter serves as the spring 22 being restrained by the base of the nose-piece 2. The tube 15 is provided with a nose or projection 23 which when the pawl 17 is nearly in its most forward position contacts with an inclined cam edge 17 of the pawl and lifts it clear of the rack 14. The reason for this will be described later. The circular space surrounding the tube 13 in the enlarged portion 11 of the barrel can be utilized as a magazine for spare leads.

The working of the device is as follows WVhen it is-desired to advance the lead for writing purposes, the button 5 is depressed and this in turn causes the tube 13 to be depressed against the strength of the spring 22 carrying with it the rack 14 owing to the engagement of the pawl 17 with the latter, and thus advancing the lead 16 a fixed amount. On releasing the button 5, the rack 14 is held in its position by its friction-tight fit in the tube 15 but the tube 13 is returned by the spring 22 to its original position, the pawl 17 slipping over the teeth of the rack. This operation can be repeated as long as any lead is left in the tube 15, the length of the toothed portion of the rack member 14 being made preferably equal to the length of the lead 16 so that the rack itself never protrudes from the tube 15.

hen the pencil is not in use, it may be desired to enclose the lead entirely within the nose-piece so that it shall be in no danger of breakage. Now it will be understood that if the pawl 17 were constantly in engagement with the rack 14-, the latter could only be moved in one direction, that is, forward. I therefore provide the nose 23 on the tube 15 which towards the-end of the forward movement of the pawl 17 comes into contact with the latter and raises it out of engagement with the rack. At this moment the rack and therefore the lead 16 can be pushed in either direction and therefore if it is desired to protect the lead from breakage the button 5 should first be depressed, and then while depressed, a slight pressure on the lead will return it within the nose-piece 2 and the button 5 can then be released.

I claim In a pencil, a barrel, a guide therein for a lead, a bar mounted for axial movement to push the lead and having ratchet teeth, a tube longitudinally movable in the barrel and in which tube the said bar is arranged, said tube being provided at its front end with spaced lugs, a spring to move said tube rearwardly, a pawl pivotally mounted between said lugs of said tube and thereby carried by the latter and arranged to engage the ratchet teeth, and fixed means effective on an extremely forward movement of the said tube and said pawl to disengage said pawl from the ratchet teeth to permit rearward movement of the lead and of the pawl.

SYDNEY ERNEST SMITH.

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