Floating Die Paper Punch

Paper punches made of molded plastic which punch holes in a limited number of sheets are old. Such prior punches have at times failed to align the top arm and base portion punching parts to accomplish adequate punching.

Broadly, the present invention comprises a punch having a base and an arm which includes punch pin elements and die holes the mating of which punches holes in sheets of paper. To create alignment of such pin element and the corresponding hole floating units are used which units carry either the pin element or its hole. As the arm and base are brought together, alignment projections cause the floating units to be properly positioned.

It is a feature that the punch may be molded of plastic material with tolerances to accomplish proper pin-hole alignment for punching.

FIG. 1 is a plan view of the punch of the present invention with the top arm nearly closed;

FIG. 2 is a plan view of the punch with the top arm removed revealing the floating die units;

FIG. 3 is a sectional elevational view, similar to FIG. 4, showing the top arm in the open position;

FIG. 4 is a sectional view taken along line 4--4 of FIG. 1;

FIG. 5 is a sectional elevational view, similar to FIG. 4, showing the punch arm completely closed;

FIG. 6 is a sectional view through line 6--6 of FIG. 5; and

FIG. 7 is a plan view of a die unit.

In the Figures, punch 10 includes base 11 and pivotal top arm 12. Base 11 has body portion 14, ears 16, 17 with hinge mounts 18, 19, 20 and ring binder receiving holes 21, 22. Base 11 also includes measuring portion 23.

Body portion 14 having width (W) and length (L) includes three (3) recesses 26, 27 and 28 in which three (3) floating die units 31, 32 and 33 are positioned for small movement (about 0.015 inch) in recesses 26, 27, 28 in the longitudinal direction (LD) and in the transverse direction (WD). Each die unit 31, 32, 33 includes floating die holes 31a, 32a, 33a and guide opening 31b, 32b, 33b. The distances (D) between die holes 31a and 32a and between 32a and 33a are about 4.25 inches. Base 11 also includes base die holes 11a, which are aligned with and slightly larger than the floating die holes (see FIG. 3). Guide openings 31b, 32b and 33b also extend through die unit raised portions 31c, 32c, and 33c.

Turning to FIGS. 3-5, top arm 12, hinged about base hinge mounts 18, 19, 20, carries paper punch pins 37 and guide projections 42. Guide projections 42 enter floating unit guide openings 31, 32, 33 as top arm 12 is lowered through arc (R) (FIG. 3) about hinge pivot (HP) (FIG. 3). Projections 42 have curved front sides 42s. Openings 31b, 32b and 33b have partially flared front walls 50. The distances d.sub.1 and d.sub.2 between pivot HP and guide projection 42 is preferably less than one inch with distance d.sub.1 being about 0.496 inch and d.sub.2 about 0.379 inch. Projections 42 act to independently position their respective floating die units 31, 32, 33 in respective base recesses 26, 27, 28 (FIGS. 3 and 4) before punch pins 37 engage sheets S.sub.1, S.sub.2 (FIG. 3) and enter die holes 31a, 32a, 33a to punch sheets S.sub.1 and S.sub.2. Since distance d.sub.1 is substantially less than distance D holding tolerances in plastic molding to improve pin-to-die alignment are greatly improved.

The floating die units 31, 32, and 33 are preferably rectangular but any shape may be used. Units 31, 32, 33 are smaller than recesses 26, 27 and 28 to permit units 31, 32, and 33 to move a short distance in any direction such as WD or LD to permit alignment of the punch pins 36, 37 and 38 with their die holes 31a, 32a, and 33 even though punch parts, as fabricated, assembled, and operated, might otherwise cause misalignment.

In FIG. 6 it is seen that raised portion 32c has additional sloping sides 52, 53 for guiding projection 42 thereon. Floating unit 32 also includes lower wedge portions 58, 59 to retain unit 32 in base 11.

Finally in FIG. 7, there is shown raised portion 32c, flared front walls 50, two flared side walls 52, 53, all such walls to guide projections 42. Also shown are guide opening 31b and die opening 31a.