JPS6230822B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotary cutter for a document shredding machine;
More specifically, the present invention relates to a rotary cutter for a document shredding machine for shredding discarded documents into chips.

Conventionally, a large number of rotary cutters were fitted onto two rotating shafts parallel to each other, and serrated teeth were provided on the outer periphery of the cutter.
The tooth tip has a front edge that stands up in the forward direction of rotation of the rotary cutter so as to be substantially perpendicular to the dedendum circle or inclined forward.

Such a known cutter is equipped only with the above-mentioned tooth tip, and the document is perforated by the tooth tip, and both sides of the perforated portion are cut by the interference part of the rotary cutter to obtain finely chopped chips. A document shredding machine has been proposed. In this shredding machine,
Spacers are placed between the many cutters to prevent the chips from getting wrapped around them.

In the above structure, the chips shredded by the rotary cutter remain attached to the wall between the tips of the teeth of the rotary cutter as the rotary cutter rotates, and the chips are separated from the tips of the teeth between the adjacent spacers. , chips are deposited between adjacent spacers, and eventually the chips deposited between the spacers become hard and interfere with the outer periphery of the rotating cutter, applying a brake. Therefore, the throughput of the rotary cutter is significantly reduced. Furthermore, in this case, the spacer chip must be cleaned periodically, which is inconvenient.

Therefore, the present invention improves this drawback and prevents chips from adhering to the valley near the tearing blade by forming a chip floating protrusion in front of the tearing blade of the rotary cutter in the rotational direction. This effectively separates the chips from the rotary cutter and prevents the chips from accumulating between the spacers.

Next, embodiments of the present invention will be described with reference to the drawings.

FIGS. 1 and 2 show a document shredding machine employing a rotary cutter as an embodiment of the present invention, which has bearings 10 and 10' at both ends, and rotating shafts 12 and 12' extending parallel to each other. has.

These rotating shafts 12, 12' are provided with a large number of rotating cutters 14, 14', respectively, with inner holes 16, 14'.
16'.

Inner hole 16, 1 of each rotary cutter 14, 14'
6' has a hexagonal shape, and the rotating shaft 1 has the same shape.
2 and 12', each rotary cutter also rotates.

A plurality of tearing blades 18, 18' are formed at appropriate intervals on the outer peripheral edge of each rotary cutter 14, 14' so as to have acute triangular tips. For example, the front edge of the triangular tearing blades 18, 18', that is, the front edge in the rotational direction of the rotary cutter, is relative to the cutting edge circle (virtual circle connecting the cutting edges) of the cutting blade. It is formed to stand up at an obtuse angle. The points of these tearing blades are sharply angled and serve to cut horizontal slits in discarded documents as described below.

According to the present invention, the chip floating protrusions 20, 20 protrude radially forward from the troughs 18a, 18'a of the cutting blades 18, 18' of the rotary cutters 14, 14' in the rotational direction. ' is formed. That is, there are chip floating protrusions 20, 2 on the blade base circle.
0' are formed to protrude in the radial direction. In the illustrated embodiment, each chip floating protrusion 20, 20' extends from the trough 22 of the tearing blade to the trough 22 of the tearing blade.
leading edges 20a, 20'a rising at an obtuse angle with respect to the tangent line of 2;
Intermediate edges 20b, 20'b extending in the outer circumferential direction from
and the tearing blades 18, 1 from the intermediate edges 20, 20'b.
8' trough 18a, trailing edge 20c extending to 18'a,
20'c. In the illustrated structure, the chip floating protrusions 20, 20' are shown as having a trapezoidal cross section, but they may have other shapes, such as semicircular or triangular shapes, if the diameter is larger than the trough of the tearing blade. It's okay to be.

The engagement position of the rotary cutters on both shafts is the first
As shown in the figure, the tearing blade 18' of the rotary cutter 14' on one shaft 12' crosses the front edge 20a and the intermediate edge 20b of the rotary cutter 14 on the other shaft 12.
It is preferable to arrange them so that they mesh in the vicinity of 0d.

Spacers 30 and 30' are fitted between the rotary cutters 14 and 14', respectively, so as to be interposed alternately with the rotary cutters. These spacers 30, 30' are supported so as not to rotate by rods 32, 32'. These spacers have slopes 32 and 32, respectively, to prevent chips from rolling up.
32'a is provided.

In the above configuration, when the document D to be shredded is inserted from above, the document D is first cut between the spacers 30 and 3.
It is inserted between the rotary cutters 14, 14' which are engaged with each other from a gap of 0'. Rotating cutter 1
The document D inserted between 4 and 14' is first formed with a horizontal slit D1 by the tearing blade 18' of the rotary cutter 14' as shown in FIG. According to Since it is floated by the leading edge, the tip D' falls freely when the rotation of the rotary cutter progresses and reaches a range where it becomes disengaged. Thus, the chips are effectively removed from the rotary cutter without sticking to the wall of the tearing blade 18.

As described above, according to the present invention, a tip floating protrusion is formed in front of the tearing blade of the rotary cutter in the rotational direction and protrudes in the radial direction from the valley of the tearing blade. Since the tip is made to float from the trough, the tip can be efficiently removed from the outer periphery of the rotary cutter without being caught by the tearing blade of the rotary cutter. Therefore, the document shredding machine can be operated for a long time without reducing its shredding ability, and the trouble of cleaning the spacers regularly as in the conventional method is eliminated.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of a document shredding machine employing the rotary cutter of the present invention, Fig. 2 is a cross-sectional view of the document shredding machine of Fig. 1, and Fig. 3 is a partially enlarged view of Fig. 1. shows. 12, 12'... Rotating shaft, 14, 14'... Rotating cutter, 18, 18'... Tearing blade, 20, 20'... Chip floating protrusion, 30, 30'... Spacer.

Claims (1)

[Scope of Claims] 1. It has two rotating shafts that are parallel to each other, and a large number of rotating cutters and spacers that rotate together with the shafts are fitted into each shaft alternately, and the rotating cutters on both shafts mesh with each other. In a rotary cutter for a document shredding machine arranged as follows, the rotary cutter has tearing blades having sharp points at appropriate intervals on the outer periphery, and radially extending from the valley between the adjacent tearing blades. a protruding protrusion for floating chips, the protrusion having a leading edge that stands up at an obtuse angle with respect to the outer periphery at the front in the rotational direction of the rotary cutter. Rotating cutter.