DE2833329A1 - Cutting punch for stacked paper - has notched helical symmetrical end cutting faces ensuring uniform cutting force - Google Patents

Abstract

The hole puncher is used for making holes into stacked paper. The punch end profile is designed to reduce the necessary cutting force. The punch end has notches forming symmetrical cutting faces relative to the punch centre line (2). The cutting edges of these symmetrical inclined faces form part of a helical line with constant cutting angle. Max. cutting force is appreciably reduced and made more uniform.

Description

Cutting punch for punch

The invention relates to a cylindrical punch for punches with an end face forming a notch.

When punching several sheets of paper on top of each other, in particular or entire stacks of paper up to the thickness of the punch slot are considerable forces required to carry out the punching. This starts with the initial cut, in which a very high force is generally required first, which is in the Intermediate phase is broken down differently and also differently in the final cut can be strong.

You already have to reduce the force required when punching proposed a cylindrical punch by means of a notch in two with the The punch axis essentially forms two halves of the same size inclined surfaces subdivide the planes of which a cutting line running parallel to a diameter exhibit. If one looks at such a cutting punch in the direction of the notch, then two rectilinear surfaces are created evenly towards this notch, while when viewed at right angles to the notch, two uniform circular arcs as cutting edges you can see. This execution has the consequence that with the round starting cut still a relatively large force is required to start the cut cause this force to be reduced variably in the intermediate phase and in the pointed end cut only has a small force deflection.

Proceeding from this, a solution has been sought that is proportionate high power to achieve the initial cut belittle, in such a way that largely uniformly throughout the entire cutting process strong or weaker pressure must be exerted on the cutting punch. Solved the problem has been that the cutting edge course of a helix corresponds to a substantially constant angle of intersection in the development Has.

With a cut edge designed in this way, the max.

Cutting force significantly reduced and equalized. The initial cut is already pointed and therefore requires significantly less force than the known ones Suggestions. The intermediate phase can also be carried out with a constant cutting force up to the final cut be performed.

The accompanying drawing shows the invention schematically. Shown is an inventive cutting punch in Figure 1 looking in the direction of the notch and in FIG. 2 with a viewing direction at right angles to the notch. The cutting punch is with 1, the notch with 2, while the cut surfaces with 3 are. In Figure 3, the development of the cut edge 3 is shown everywhere has substantially constant cutting angles.

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Claims (1)

Patent claim cutting temples for punches with a notch forming Front face, which is symmetrical with the punch axis 2 essentially the same size Forms cut surfaces, characterized in that the edge of this is symmetrical Inclined surfaces are part of a helical line, which in the bend is a substantially has a constant cutting angle.