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Publication numberUS2312069 A
Publication typeGrant
Publication dateFeb 23, 1943
Filing dateFeb 25, 1942
Priority dateFeb 25, 1942
Publication numberUS 2312069 A, US 2312069A, US-A-2312069, US2312069 A, US2312069A
InventorsBaumgartner John G
Original AssigneeBaumgartner John G
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Protector cap
US 2312069 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

1943' J. a. BAUMGARTNER 4 ,31 ,069

PROTECTOR CAP Filed Feb. 25, 1-942 Patented F eb. 23, 1943 with STATES PATENT r 6 Claims.

This invention relates generally to protector caps and in particular to a cap for covering the operatin or exposed end of pencil devices.

The use of drawn metal caps for capping pencil devices and the like is well known. These metal caps have been used with ordinary lead pencils, for eyebrow pencils and for many other types of pencils where there wa danger of the exposed or operating end of the pencil becoming broken from handling or storage, or of touching and possibly discoloring adjacent articles. The metal caps are usually formed in one piece and generally comprise a substantially conical portion closed at the tip or apex thereof and a cylindrical portion having an open end. The cylindrical portion adjacent the open end is usually split in an axial direction along one side thereof to provide for its being spread apart on insertion of a pencil therein. As a result the cylindrical body portion of the pencil is frictionally engaged by th cylindrical portion of the metal cap due to resiliency resulting from the split therein, whereby the cap is retained on the pencil and in a covering relation with respect to the operating end thereof. These prior art metal caps although generally satisfactory are rather expensive because of their metal construction and further are unadapted, without appreciable additional expense, to be colored or designed for harmonious blending with the coloring and design of the pencils with which they are associated.

It is an object of this invention, therefore, to provide an improved protector cap.

Another object of this invention is to provide a non-metallic protector cap for pencil devices.

Yet another object of this invention is to provide a non-metal protector cap for pencil devices which is relatively inexpensive in cost, readily adapted to be designed and colored to correspond with an associated pencil, and which is releasably retained on the pencil by frictional engagement therewith.

A feature of this invention is found in the provision of a plastic protector cap for pencil devices which is provided on the inner periphery and intermediate the ends thereof with a substantially rigid axially extending radially projecting portion having one end terminating in such periphery and which is tapered in a direction axially of the cap so as to frictionally engage a pencil device inserted within the cap.

Further objects, features, and advantages of this invention will become apparent from the following description when taken in connection with the accompanying drawing in which:

Fig. l is a complete assembly view of the protector cap of this invention with an associated pencil device;

Fig. 2 is a longitudinal sectional view of the protector cap taken approximately along the line 2--2 of Fig. 3; and

Fig. 3 is a transvers sectional view as seen along the line 33 of Fig. 2.

Referring to the drawing the cap 5 of this invention is shown in Figs. 1 and 2 being adapted for capping a pencil 6 having a cylindrical body portion l and a tapered or operating end E. For purposes of illustration the pencil 6 is shown as having a cylindrical body but it is understood that a pencil with a square or polygonal-shaped body can be protected in the same manner. The cap 5 is of a substantially tubular or sleeve form con structed in one piece and composed of Bakelite or like moldabl material. The cap is comprised of a cylindrical portion 8 and a tapered or conical portion 9, the junction of these tWo portions being indicated at H]. The conical portion 9 is tapered inwardly away from the cylindrical portion 8 and is closed at the tip or apex end i I of the cap. The opposite end IQ of the cap 5, and at the cylindrical portion 8, is open to receive the pencil 6 therein. Intermediate the cap ends 5! and i2 are axially extending substantially wedge-shaped ribs or ridges l3 formed on the inner periphery of the cap and projected radially thereof. The ribs 23 (Fig. 3) are angularly spaced about the cap and are substantially rigid relative to each other and to the cap portions 8 and 9. Each rib 3, at the end M thereof, terminates in the inner periphery of the cap and is tapered in an axial direction toward the closed cap end i i at an angle depending upon the angle of the tapered end E of the pencil 1.

In one embodiment of the invention the cap 5 is about one and one quarter inches long, with the rib or wedge-shaped portions 13 being about a half an inch long and extended substantially equal distances to each side of the junction IU of the cap portions 8 and 9. The cylindrical cap portion 8 has an inner diameter which is about one thirty-second of an inch greater than the diameter of the cylindrical body portion 7 of the pencil 6, or about e e" greater than the diameter of a circle through the outside points on a polygonal or square-shaped body. As is well known in the making of pencils the diameters of the same type pencil vary appreciably. The cylindrical portion 8, therefore, is adapted to accommodate pencils of like kind regardless of any slight variations in their relative diameters.

the ribs 13 all pencils adapted to be inserted within the open end I2 of the cap are frictionally engaged by the ribs regardless of any slight variations in their relative diameters or the relative angles of their tapered ends E. These variations,

of course, position the small ends of the tapered 7 pencil portions E of the pencils at slightlydifierent points in the cap 5. However, sufficient space is provided at the closed apex end H of the cap to allow for these variations so that the cap is always frictionally retained on the pencil and in a protecting or covering relation with the operating end thereof. By virtue of this engagement of the wedge portions 13 with the pencil 6 there is accomplished a positive frictional holding of the cap on the pencil while providing for .a free and easy removal of the cap from the pencil when the end E thereof is to be used.

From a consideration of the above description and drawing, therefore, it is seen that the invention provides a non-metal cap for pencil devices which is of a rugged construction and easily manipulated to a capping position. Since the cap is of a non-metal construction, and composed of a plastic material it can be readily colored or intricately designed to correspond with the design of the pencil without in any manner increasing 3 the cost thereof. The tapered construction of the wedge portions 13 readily adapts the cap'to a plurality of pencil devices having different ized diameters or tapered end portions without impairing the efficient capping function thereof. Although the wedgeportions l3 have been described and illustrated as being plural in number and :angularly spaced aboutthe inside of the cap '5, it is apparent of course'that a single wedge portion extending entirely about the inside of the capmay be used within the limits of this invention. It is also apparent, that in some instances the end I! of the cap may be left open with the axial extension of the periphery of the cap providing sufficient protection for the operating nd 0f the pencil.

Although the present invention has been described with specific reference to a particular embodiment thereof it is to be understood that it is not to be so limited since changes and modifications can be made therein which are within'th'e full intended scope of this invention as defined by the appended claims.

I claim:

1. A protector cap for a pencil device, said cap comprising a cylindrical portion and a conical portion joined at their adjacent ends, with an axially extending wedge-shaped portion projecting inwardly of said cap at the junction of said cylindrical and conical portions, said wedgeshaped portion adapted to frictionally engag a pencil device to retain said cap thereon.

2. In a pencil device having a tapered end, a

said cap being closed at one end and open at the other end thereof, an axially extending ridge on the inner surface of said cap tapered inwardly towardsaid closed end and having one end thereof spaced from said open end and terminating in said inner surface, said ridge engaging said tapered portion substantially at the large end thereof to frictionally retain said cap on said pencil device.

4. In a pencil device having a tapered endportion, a cap for covering said tapered portion comprising a cylindrical portion and a substantially conical portion tapered inwardly away from said cylindrical portion and closing said cap at one end thereof, said cap being open at the opposite end thereof, a plurality of ridges angularly spaced on the inner surface of said cap and extended axially thereof to each side of the junction of said cylindrical and conical portions, each of said ridges having one of their corresponding ends terminating in the inner surface of said cylindricalportion, said ridges on insertion of said pencil tapered portion within the cap at said open end frictionally engaging said pencil device substantially at the large end of said tapered end portion to retain said cap on said pencil device.

5. A protector-cap open at one end for fitting over one end of a pencil-like device to be frictionally retained thereon but adapted to be removed therefrom with a substantially straight pull, said protector cap being hollow on the inside and including on said inside a portion which is substantially straight longitudinally of the cap extending from said open end, a tapered portion extending longitudinally of the cap away from said substantially straight portion, and a projecting 'portionon said inside extending'longitudina'lly of thecap over the area of the junction of said first two named portions andtape'ring inwardly into the cap in the longitudinal direction away from said open end.

6. A hollow protector-cap open at one end and adapted to fit over a pencil-like device which has a substantiallystra ight body portion and a substantially taperedend portion extending there,- from with a junction portion therebetween, said cap on the inside "thereof having a plurality 'of ridges extending substantially longitudinally of the cap, with each such ridge extending from a point spaced from the open end and tapering-inwardly in the longitudinal direction away from saidopenend, with said ridges being adapted to frictionally engage'a pencil-lil e device substantially at the junction portion of the device when the protector-cap is placed on such device.


Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2893109 *May 18, 1956Jul 7, 1959Eagle Pencil CoLead pencil
US4302121 *Oct 19, 1979Nov 24, 1981Kim Jung SBall-point pen having three sides and complementary cap
US5911534 *Nov 18, 1996Jun 15, 1999Zebra Co., Ltd.Cap for writing tool
US6227743 *Jul 1, 1999May 8, 2001Karl A. RobbPen cap stylus for use with touch screens
US6439791 *Jan 19, 1999Aug 27, 2002Nec CorporationGrip and cap for writing tool, and writing tool
US7131785Jul 26, 2004Nov 7, 2006Amir A MansouriChewable top for a wiring instrument
DE914226C *Aug 2, 1951Jun 28, 1954Hermann HankeSchutzspitzer
EP0705716A1 *Jan 17, 1995Apr 10, 1996Zebra Co., Ltd.Cap for writing tool
U.S. Classification401/98
International ClassificationB43K23/10, B43K23/00
Cooperative ClassificationB43K23/10
European ClassificationB43K23/10