US2520752A - Cap holding means for fountain pens - Google Patents

Description

Aug. 29, 1950 A. M. ANDAUER CAP HOLDING MEANS FOR FOUNTAIN PENS Filed July 22, 1947 FIG.5

INVENTOR ALFRED M. ANDAUER ATTORNEYS FIG.3

Patented Aug. 29, 1950 UNITED STATES serum OFFICE Alfred M. Andauer, Baldwin, N.Y., assignor to Universal Fountain Pen & Pencil (30., 1 110., New York, N. Y., a corporation of New York Application July 22, 194.7,Se1ial No. 762,666

3 Claims. 1

This invention relates to means for holding the cap of a fountain pen in place on the pen. Not only should the cap be held firmly on the upper end of the pen during writing, but what is more important, it must be securely held over the nib, stylus, or ball when the pen is not in use, and, in the latter position, should serve to prevent evaporation of the ink so that the pen will be in condition for instant writing when the cap is removed.

Various means have hitherto been employed for holding fountain pen caps in position: screw threads, friction, snap springs on the cap engaging an annular groove in the pen barrel. These are either expensive or ineflicient. According to the present invention I employ a leaf spring riveted to the top of the cylindrical cap shell and extending down along its inner wall. When the pen is inserted the Spring is pressed against the wall of the cap and assumes its curvature, meanwhile exerting a gripping spring pressure against the pen and holding the cap snugly in place. I preferably employ a U-shaped spring with its two arms engaging the pen on opposite sides. The spring is also preferably arcuate in cross-section, of a curvature slightly less than that of the shell and with the concave faces opposing when the spring is mounted within the cap. As the spring is very thin.010 inch and covers about half the circumference of the cap when the pen is inserted, the fit is substantially air-tight. In any event, experience has shown that the writing end of a fountain pen closed with my cap remains capable of instant writing after long periods of disuse.

Not only is the spring of my invention efiicient for its purpose, it is inexpensive. It can be made in strips, cut to the proper unit length, a hole punched in the middle of the unit for a rivet, the spring bent to U-shape, inserted into the shell and riveted in place.

In the accompanying drawing I have illustrated a preferred embodiment of my invention. In this drawing Figure 1 is a longitudinal section through the empty cap of a fountain pen equipped with one of my springs,

Figure 2 is a transverse section taken along line 2-2 of Figure 1,

Figure 3 is a transverse section similar to 2 Figure 2, but showing a, pen barrel inserted in the cap and the holding spring flexed into gripping position,

Figure 4 is a plan view of an unbent spring unit, and

Figure 5 is a perspective view of the spring of Figure 4 bent into U-shape and ready for mounting within the cap.

The cap shown in these drawings comprises a cylindrical shell I, having a slightly tapered or conical upper end, withinwhich is mounted the spring of my invention. This spring is cut from a strip of phosphor bronze, or other suitable material, slightly dished, and a rivet hole 2 is punched through its middle to form the unit strip 3 shown in Figure 4. Ihis unit strip is then bent into the U-shape shown in Figure 5 with the concave surfaces of the depending arms 4 opposing each other. The spring is then inserted into the shell and riveted in position by means of a rivet 5, which also serves to rivet a clip 6 to the shell.

When the parts are assembled, as just described, the arms of the spring lie against the inner Wall of the shell, as shown best in Figure 2. The radius of curvature of the spring is greater than that of the shell so that the edges of the spring arms engage the inner wall of the shell, but a space 6 is left between the outer face of each spring arm and the adjacent inner wall of the shell. This is the position of the parts when the cap is empty.

When the barrel i of a pen is inserted into the cap it engages the spring arms 4 and bends them back against the inner wall of the shell until the parts take the position shown in Figure 3. Thus the flexed springs exert a pressure upon the pen and hold the cap firmly in place, although not so firmly that it cannot be readily removed.

As shown in Figure 3, the pen closes the cap except for two arcuate slots 8, as wide as the spring metal is thick and in sum about 186 in length. Thus the cap effectually seals the Writing end of the pen and prevents rapid drying of the ink so that the pen will write freely even after substantial periods of disuse.

I claim:

1. A fountain pen cap comprising a cylindrical shell and a leaf spring mounted witlun the shell and lying along its inner wall, the spring having 3 a transverse curvature less than that Of the shell with its concave surface facing inward.

2. A fountain pen cap comprising a cylindrical shell and a U-shaped leaf spring mounted within the shell with its arms lying along the inner wall of the shell, the arms being arcuate in crosssection with their concave surfaces opposing each other and of a transverse curvature less than that of the shell.

3. A fountain pen cap comprising a cylindrical shell, a U-shaped leaf spring mounted within the shell with its arms lying along the inner wall of V the shell, the arms being arcuate in cross-section REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PA'I'ENTS Number Number 15 158,560

Name Date Smith Aug. 9, 1892 Tredwell Sept. 19, 1905 Blackman May 8, 1928 Johnson Oct. 23, 1928 Blackman Mar. 19, 1929 Kirsch Oct. 27, 1931 Cuthbert Aug. 16, 1932 Baker Apr. '7, 1942 Lytton Mar. 19, 1946 FOREIGN PATENTS Country Date Switzerland Feb. 1, 1933

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