Paper perforating device

A sheet perforating punch formed of hard polymeric material formed of a punch plate with punching teeth and a die plate with holes intended to be registered with the teeth, snap-together hinging being provided for rotatably coupling the two plates together along respective edges thereof so that the registration of corresponding ones of the holes and teeth are fixed and so that no discernible relative axial displacement or travel of the two plates is permitted.

What is claimed is:

1. A punch device for providing holes in sheet material, and comprising;

an elongated, substantially flat die plate formed of substantially rigid, hard, polymeric material and having a plurality of holes therethrough predeterminedly spaced from one another and disposed along a first linear axis;

an elongated, substantially flat punch plate also formed of substantially rigid, hard polymeric material and having a plurality of teeth projecting therefrom in said predetermined spacing and disposed along a second linear axis;

means, formed of polymeric material, for rotatably hinging said two plates together along respective edges thereof so that holes and teeth are in fixed registration with one another and so that no discernible relative axial displacement or travel of said two plates is permitted, said means comprising a plurality of elongated posts fixed to at least one of said plates, and a like plurality of corresponding tubular sockets fixed to the other of said plates, said posts and sockets being so arranged that said posts extend colinearly with one another into respective ones of said sockets and said sockets are rotatable about said posts, said means being so dimensioned and constructed that when said posts are fully extended within said sockets, said posts and sockets cannot be disengaged without seriously damaging said hinging.

2. A punch device as set forth in claim 1 wherein said means for hinging is so dimensioned and constructed that said first and second axes are maintained parallel to one another and said plates are rotatable about a third axis parallel to and spaced from said first and second axes.

3. A punch device as defined in claim 1 wherein the unhinged edges of said plates, opposite to said respective edges, are angularly offset from one another so as to be non-parallel and to permit ready manipulation for rotating said plates relative to one another about a common axis adjacent said respective edges.

4. A punch device as defined in claim 1 wherein one of said plates includes a pair of flat ears extending outwardly from said one of said plates in the plane thereof, each of said ears having an aperture therein, said apertures being spaced apart by a distance equal to that between the outermost rings of a loose-leaf binder in which said punch can be stored, at least two of said posts each being respectively mounted on edges of corresponding ones of said ears so that the axes of elongated of said posts extend colinearly substantially perpendicularly to said edges of said ears substantially in the plane of said one of said plates.

5. A punch device as defined in claim 1 wherein

one of said elongated posts is mounted on one of said plates adjacent an edge thereof so that the long axis of said post is parallel to and spaced from said edge, said one of said elongated posts being formed of a stiff but elastically deformable polymer and including a cylindrical shaft of predetermined length, one end of said shaft bearing a rounded head;

a tubular polymeric socket mounted on the other of said plates adjacent an edge thereof so that the axis of elongation of said socket is parallel to and spaced from said edge, the interior of said socket being formed of two colinear tubular sections one of which is of greater diameter than the other so as to define at one end of the tubular section of lesser diameter, an intermediate internal shoulder spaced from the other end of said tubular section of lesser diameter by said predetermined length,

said smaller-diameter section having substantially the same diameter as said shaft, and the diameter of said head being greater than the diameter of said shaft;

said head having an axially directed slot therein to permit said head to be distorted sufficiently in diameter to be inserted into said tubular section of lesser diameter.

6. A punch device as defined in claim 5 including at least a pair of other posts extending colinearly with said shaft and a pair of elongated sockets in which said other posts can be rotatably inserted, the axes of said sockets extending colinearly with the axis of said tubular section.