US2552402A - Apparatus for sharpening pencil refills - Google Patents

Description

y 8, 1951 H. BUSER 2,552,402

APPARATUS FOR SHARPENING PENCIL REFILLS Filed March 18, 1947 FIG. I FIG. 2

"Inventor:

HANS 'BUSER,

Attorneys:

Patented May 8, 1951 REFILLS Hans Buser, Zurich, Switzerland I Application March 18, 1947, Serial No. 735,317 In Switzerland December. 29, 1944 Section 1, Public Law 690, August 8, 1946 Patent expires December 29, 1964 Claims.

The present invention relates to an apparatus ,for sharpening pencil refills having means proof contact in different directions or in the samedirection but at different speeds.

Further features of the invention will be apparent from the following description and the drawing setting forth preferred embodiments'of the invention.

In the-drawings: Y

Figure 1 is a cross-sectional view of one embodiment of the invention;

Figure 2 is a longitudinal section of the embodiment of Figure 1; I

Figure 3 is a cross-sectional view on the line wa of Figure 4;

Figure 4 is a, horizontal sectional view of a second constructional embodiment;

Figure 5 is a horizontal sectional view on the line 22-12 of Figure 1, and

Figure 6 illustrates a detail.

In the case of the first constructional embodiment shown in Figures 1 and 2, the pencil-refill rests for sharpening purposes only due to the weight of the refill-holder 5, on the friction-surface of a slanting file I, which is attached by means of two connecting pieces 2 to a slide 7. The slide 1 can be moved to and fro in the longitudinal direction in the casing a (Figure 1) and in the course of this movement carries the file with it. The slide 1 serves as driving means. On the slide 7 there is fastened a rack 3 which engages in a pinion 4 which is rigidly attached to a sleeve 4a. This sleeve 4a is arranged in vertical or approximately vertical position in a holder on the casing 8 and is rotatably mounted therein. The refill-holder 5 of a pencil-refill can be inserted in the sleeve 4a until the tip of the refill rests against the file l. The refill-holder 5 is secured against twisting in the sleeve 4a by means of a sexagonal holder having three set screws l3 arranged radially in the sleeve (Figures 1 and 5), which are distributed at even distances over the periphery thereof. These screws I 3 are set in such a way that the refill-holder can slip down the sleeve by virtue of its own weight until the tip of the refill rests against the file I. In the pinion 4 of the sleeve 4a there is a hole which 2 serves to limit the depth to which the refill-holder can fall and thus prevents any damaging of the latter.

As the refill-holder may vary considerably in size, which fact may cause difficulty for an exact centering of the pencil-refill inasmuch as the latter can easily break off, a centered bore is provided as clearly shown in Figure 6 in the lower part, i. e. in the pinion part of the sleeve 4a, which bore corresponds to the diameter of the refill. This serves to center the refill and at the same time limit the depth to which-the refillholder 5 can fall.

.Due to the arrangement of the friction surface I on the opposite side of the refill from the point of pinion engagement with the rack 3, these two parts will move in opposite directions atthe common point ofcontact of the tip of the refill and the friction surface 1, whereby an effective sharpening of the refill is achieved.

The casingv 8 is completely closed and under the refill point a container can be provided to hold the graphite dust. This container (which is not shown in the drawing) can be slipped in and out of the casing for emptying the graphite dust.

The mode of operation is apparent from Figures 1 and 2. The refill-holder together with the refill is inserted from above into the sleeve 4a and lowered until the tip of the refill rests against the friction member. The slide 1 is moved back and forth once or twice, which will effect sharpening of the refill. The refill-holder is then taken out of the sleeve 4a together with the sharpened refill.

In the case of the embodiment as in Figures 3 and 4, the friction member consists of a disc 9 in the form of a truncated cone, the jacket of which is designed as a friction surface and against which the tip of the refill of the refillholder inserted into the sleeve 4a rests. The axis of the friction disc 9 is connected via a pinion 9a to a gear wheel I2 on whose axis a pinion I 2a is mounted which meshes with the toothed sector lea of a pivoted lever I!) having a spring H connected thereto. On operating thumb lever It), the friction disc 9 is turned and, via the pinion and the sleeve do, also the refillholder 5 and the refill. After each movement the thumb lever 19 is returned to its initial position by the tension spring H. Due to the arrangement of an intermediate gear wheel I? the sleeve 4a with the refill-holder 5 and the refill on the one hand, and the friction disc 9 on the other hand, are driven in opposite directions, so that with one or two operations of the thumb lever H] a sharp refill-tip is obtained.

I claim:

1. Apparatus for sharpening pencil-refills comprising a casing, a substantially vertical hollow sleeve in said casing, said sleeve constituting a holder for a pencil refill, said refill-holder being loosely inserted in said sleeve and a small inter.- mediate space being formed between said refillholder and said sleeve, a screw inserted in a side of said sleeve and passing therethrough, said screw loosely coacting with said refill-holder to prevent relative rotation between said sleeve and said refill-holder and allow free longitudinal movement of said refill-holder, said sleeve being rotatable, a pinion on the lower end of said sleeve, a slidable rack member in contact with said pinion, drive means for said rack, a friction member comprising a file rigidly connected with said rack for movement therewith, said rack and said friction member being on different sides of the axis of said refill-holder, said refill resting against said file by virtue of its own weight, said file sharpening said refill on movement thereof.

2. Apparatus as claimed in claim 1, characterized in that the rack is so arranged that the file and the refill move at the common point of contact in difierent directions.

3. Apparatus as claimed in claim 1, characterized in that the driving means consists of a slide which can be moved to and fro in the casing.

4. Apparatus as claimed in claim 1, characterized in that said sleeve serving to hold the refill-holder has at the lower end thereof in the central axis a centered bore, said bore being dimensioned in accordance with the diameter of the pencil-refill, so that said refill is guided by said bore and can be moved in said bore both in rotatory and longitudinal directions.

5. Apparatus for sharpening pencil-refills comprising a casing, a substantially vertical hollow sleeve rotatably journalled in the top of said casing and extending into said casing, said sleeve constituting a pencil refill-holder, said refill-holder being loosely inserted in said sleeve and a small intermediate space being formed between said refill-holder and said sleeve, a screw inserted in a side of said sleeve and passing therethrough, said screw loosely coacting with said refill-holder to prevent relative rotation between said sleeve and said refill-holder and allow free longitudinal movement of said refill-holder, a pinion gear fixed adjacent the lower end of said sleeve, a slide member movably mounted in said casing at substantially right angles to said sleeve, a rack connected to said slide in contact with said pinion gear, a friction member comprising a file attached to said slide and arranged in proximity to the lower end of said sleeve and at an angle thereto, said rack and said friction member being on different sides of the axis of said refill-holder, said refill inserted in said sleeve resting against said friction member under the force of Weight of said refill, said slide upon moving rotating said refill in contact with said file thereby sharpening said refill.

HANS BUSER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 211,911 Johnston Feb. 4, 1879 836,094 Cook Nov. 20, 1906 998,044 Spengler July 18, 1911 1,770,062 Blomgren July 8, 1930 FOREIGN PATENTS Number Country Date 91,352 Switzerland Dec. 1, 1921 388,588 Germany Jan. 15, 1924 151,706 Switzerland Dec. 31, 1931 298,244 Italy July 2, 1932 183,672 Switzerland Apr. 30, 1936

Images