Cutting by use of rotating axially moving tool – Means to drive tool – Including means to move tool along tool-axis
Reexamination Certificate
1999-02-22
2003-04-01
Peterson, Kenneth E. (Department: 3724)
Cutting by use of rotating axially moving tool
Means to drive tool
Including means to move tool along tool-axis
C408S136000, C408S204000, C083S164000, C083S629000
Reexamination Certificate
active
06540451
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to apparatus for punching holes in sheet material, such as paper.
2. Background of Art
It is common to bind multiple sheets of material, such as paper, using fasteners such as rings, string, metal clasps, etc. Holes are normally pre-punched in the sheet material to accept these fasteners.
One conventional apparatus for pre-punching holes in sheet material is shown at
10
in
FIGS. 1-4
herein. The hole punching apparatus
10
consists of a frame
12
defining an upwardly facing, flat support surface
14
for multiple pieces of sheet material
16
into which holes
18
are punched. The frame
12
supports two, tubular, cutting blades
20
for movement relative to the frame
12
between a retracted position, as shown in
FIG. 3
, and a cutting position, as shown in FIG.
2
. The frame
12
has two plastic backing elements
22
, provided one each beneath the cutting blades
20
. A handle
24
is mounted on the frame
12
and is repositionable from a normal position, shown in
FIG. 1
, to an actuated position, by pivoting movement of the handle
24
in the direction of the arrow
26
to thereby reposition the cutting blades
20
from the retracted position into the cutting position. In so doing, an annular cutting edge
28
, at the free end of each cutting blade
20
, is driven through either a single piece of sheet material
16
or through stacked pieces of sheet material
16
to against the plastic backing element
22
. The frame
12
supports a guide element
30
with an upturned end
32
which is abuttable to an edge of the sheet material
16
facially abutted to the support surface
14
to predetermine the position of the sheet material
16
relative to the cutting blades
20
for consistent location of the holes
18
.
In a typical cutting operation, the piece or pieces of sheet material
16
are placed against the support surface
14
and shifted into a throat portion defined by the frame at
34
and at the same time abutted to the upturned end
32
of the guide element
30
. The guide element
30
can be appropriately repositioned by movement in the line of the double-headed arrow
36
to cause the desired hole locations on the sheet material
16
to be aligned precisely beneath the cutting blades
20
. The handle
24
is then grasped and pivoted in the direction of the arrow
26
, whereupon the cutting edges
28
on the cutting blades
20
engage and penetrate through the sheet material
16
so as to form, in this case, circular cut-outs
38
therefrom. As the cutting edges
28
bear on the backing elements
22
, the bottommost piece of sheet material
16
is penetrated fully through by the cutting edges
28
.
The cutting blades
20
each have an internal cavity
40
into which the cut-outs
38
are pressed during a punching operation. Each cavity
40
has a cross-sectional area that progressively decreases in diameter moving away from the cutting edge
28
a distance D at which point the cavity
40
has its smallest diameter and area. The diameter of the cavity
40
increases beyond the distance D to a diameter slightly smaller than the diameter of the cut-outs
38
so that the cut-outs
38
become slightly compressed. The snugly held cut-outs
38
are allowed to slide within the cavity upwardly, i.e. in the direction of the arrow
42
. As each cutting blade
20
moves from the retracted position into the cutting position, the formed cut-outs
38
become squeezed progressively as they move the distance D from the cutting edge
28
through a neck
44
at the distance D. An annular ledge
46
at the neck
44
abuts to, and thereby resists downward passage of, the cut-outs
38
that have moved to thereabove.
Systems, such as that shown in
FIGS. 1-4
, may have a number of drawbacks. First of all, a substantial force may be required on the handle
24
to direct the cutting blades
20
fully through a stack of sheet material
16
. As the cut-outs
38
accumulate in the cavities
40
, the accumulating cut-outs
38
progressively increase the resistance to downward movement of the cutting blades
20
.
Another problem that may be encountered is that the cut-outs
38
that do not travel upwardly to beyond the necks
44
tend to spring out when the cutting blades
20
are moved back towards the retracted position. This may result in the cut-outs
38
having to be manually removed from the holes
18
in the sheet material
16
and/or cleaned up in the area surrounding the hole punching apparatus
10
.
In order to precisely form the holes
18
, and to do so with minimal effort, it is necessary that the cutting edges
28
on the cutting blades
20
remain sharp. In the event that the cutting edges
28
become dull, it is desirable to be able to change the cutting blades
20
, rather than replace the entire hole punching apparatus
10
. Some hole punching apparatus, similar to that shown at
10
in
FIGS. 1-4
, do not lend themselves to facilitated replacement of the cutting blades
20
.
SUMMARY OF THE INVENTION
The invention is directed to a hole punching apparatus having a frame, a blade having a tubular cutting edge and a cavity, and a projection on the frame. The blade is movable relative to the frame between a retracted position and a cutting position. The projection moves into the blade cavity as the blade moves from the retracted position into the cutting position.
With the above construction, the projection can move cut-outs formed in a punching operation sufficiently into the cavity that they do not escape as the blade is moved back into the retracted position.
The hole punching apparatus may further have a drive for rotating the cutting edge around a first axis as the blade moves from the retracted position into the cutting position.
By rotating the cutting edge, cutting of the material in which a hole is to be formed is effected not only by pressure applied in moving the blade towards the cutting position, but also by the rotary movement of the cutting edge. This may reduce the amount of force required to be applied to the blade in moving the blade from the retracted position into the cutting position.
In one form, the cavity has first and second ends spaced along the first axis, with the cutting edge being at the first end of the cavity. The cavity has a diameter taken transversely to the first axis. The diameter of the cavity is non-uniform along the first axis.
In one form, the diameter of the cavity decreases from the cutting edge up to a first predetermined axial distance from the cutting edge towards the second end of the cavity and increases from the first predetermined distance towards the second end of the cavity. The projection extends into the cavity at least the predetermined axial distance from the cutting edge.
The blade may be movable substantially parallel to the first axis between the retracted and cutting positions.
A handle may be provided that is movable relative to the frame between a normal position and an actuated position. The blade is movable from the retracted position into the cutting position as an incident of the handle moving from the normal position into the actuated position.
The handle may be pivotable about an axis as the handle moves between the normal and actuated positions.
The drive may include a drive motor for rotating the cutting edge around a first axis as the blade moves from the retracted position towards the cutting position. A switch may be provided that is placeable selectively in a) an on state to cause activation of the drive motor, and b) an off state to cause deactivation of the drive motor. The switch is moved from the off state into the on state as an incident of the handle moving from the normal position into the actuated position.
The hole punching apparatus may include a blade moving assembly and an adaptor for connecting the blade to the blade moving assembly. The blade moving assembly has a blade holder and a guide case. The blade moving assembly is translatable substantially parallel to the first axis between first and second positions as
Carl Manufacturing Co., Ltd.
Peterson Kenneth E.
Wood Phillips Katz Clark & Mortimer
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