Note: Descriptions are shown in the official language in which they were submitted.
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Background of the Invention
Field of the Invention
The present invention generally relates to a cutter. More
particularly, it relates to a cutter having a blade which is
slidably extendable to a protracted cutting position and a
retracted storage position.
Description of the Prior Art
The following conventional cutters are well known and exemplify
the state of the art in the field. A rotary cutter has a disc
shaped blade which rotatably and pivotally moves with respect to
a stationary handle. A conventional cutter knife has a straight
cutting edge. The cutting edge slidably protrudes to permit
cutting and is retracted for storage.
The rotary cutter allows the rotational friction force to be
adjusted, in order to improve the performance of the cutter. The
United States patent No. 4,301,594 discloses one type of rotary
cutters. The cutter has a slider arranged at one end section of
a handle. A disc shaped blade is secured to the slider by means
of a fastening device, at its center section. Consequently, an
appropriate rotational friction force could be applied to the
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disc blade so as to prevent a free, arbitrary rotation of the
disc blade during the cutting operation.
However, when the fastening device is excessively tightened, the
rotational friction force is significantly increased.
Consequently, the disc blade becomes hard to rotate. When the
fastening device becomes loose, the rotational friction force is
significantly decreased so that the disc blade starts to freely
rotate. As a result, the adjustment of the fastening device
becomes rather difficult. If the adjustment is improperly made,
the cutting ability of the cutter decrease.
The Japanese Unexamined Utility Model Publication No. 61-54752
discloses a cutter knife which has a straight cutting edge. The
cutter knife has a pair of grooves within its handle. The grooves
communicate with an outer peripheral end of the elongated handle.
One of distal ends of the handle is opened. When a slider is
moved along the grooves, the blade is caused to slide by the
slider so that the cutting edge of the blade protrudes beyond the
distal end of the handle, through the opening in the distal end
of the handle.
When the blade is extended by the slider and touches the inner
wall of the opening, the sliding ability of the blade
significantly decreases. Therefore, it is necessary to create
a relatively small gap between the inner wall of the opening and
the blade. Consequently, the blade that can not be securely held
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in position creates a swaying motion during the cutting
operation. As a result, the cutting ability of the blade
decreases.
Summary of the Invention
It is therefore an object of the present invention to provide a
cutter with a rotatable and slidable blade and a slider, for
stable handling.
Another object of the present invention is to provide a cutter
having a rotatable and slidable blade, such that the blade is
securely supported during the cutting operation in order to
increase the cutting ability of the cutter.
To achieve the foregoing and other objects there is provided a
cutter which includes a handle and a disc blade. The blade can
be protracted or retracted. A slider is connected to the blade
and slidably supports the handle, and permits the blade to move
between a cutting position and a storage position. A pressure
applying device includes a cantilevered elastic projection formed
on the slider to abut against the blade. The cantilevered
projection abuts against the blade when the blade is in use.
In one aspect of the present invention, a disc blade is rotatably
attached to the distal end of the handle. The distal end has a
disc shape, generally proportioned to the disc blade. When the
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disc blade is extended to forward the cutting
position, the cantilevered projection abuts against
the inner surface of the disc blade and applies a
rotational friction force to the disc blade.
In another aspect of the present invention, a blade
which has a straight cutting edge that can be
extended into a cutting position beyond the distal
end of the handle. The cutting edge is retractable
within the handle, for storage, when the cutter is
not in used. The blade is pushed against the inner
peripheral edge of the opening by means of the
cantilevered projection, in order to avert the
undesirable sway of the blade.
Therefore, in accordance with the present invention,
there is provided a cutter comprising:
a handle including an elongated groove;
a blade having a first surface and a second
surface, said first surface facing said handle, said
blade being movable between a cutting position and a
storage position;
slider means, connected to said blade and
slidably supported by said handle and along said
elongated groove, for selectively moving said blade
between said cutting and storage positions and for
holding said blade in said cutting and said storage
posltlons;
said slider means including resisting means
for frictionally resisting a free movement of said
blade during a cutting operation, a base portion that
is generally positioned in proximity of said first
surface of said blade, and a positioning portion
which extends from said base portion for securely~5 positioning the blade in one of said positions;
said handle including pressing means for
pressing said resisting means against said first
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surface of said blade when said blade is in said
cutting position;
said resisting means including a resilient
member which projects from the base portion toward
said first surface of the blade and positioned such
that said resilient member is forced toward said
first surface of the blade when said blade is moved
from said storage position to said cutting position;
wherein said blade has a generally disc
shape and is rotatably mounted on said slider means,
and wherein said handle includes a platform extended
from an end of said handle and supporting the blade
for rotation thereon.
Also in accordance with the present invention, there
is provided a movable blade cutter comprising:
a handle;
a blade having a first surface and a second
surface, the first surface facing the handle, said
blade being movable between a cutting position and a
storage position;
said handle including an elongated groove;
slider means being slidably movable within
said elongated groove and connected to said blade,~5 and slidably supported by said handle,
for switching the blade position between
the cutting position and the storage position;
said slider means including resisting means
for frictionally resisting a free movement of the~0 blade during a cutting operation;
said handle including pressing means for
pressing the resisting means against said first
surface of the blade in the cutting position; and
a platform extending from an end of the~5 handle;
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wherein the blade is rotatably mounted on
said slider means and is supported by said platform
for rotation thereon.
Further in accordance with the present invention,
there is provided a movable blade cutter comprising:
a handle;
a blade having a first surface and a second
surface, the first surface facing the handle, said
blade being movable between a cutting position and a
storage position;
slider means, connected to said blade and
slidably supported by said handle, for switching said
~ blade between said cutting position and said storage
position;
said slider means including a base portion
being generally positioned in proximity of said first
surface of said blade, and a positioning portion
extending from said base portion for securely
positioning said blade in one of said positions;
said handle including an elongated groove,
and said slider means being slidably movable within
said elongated groove;
said elongated groove including a plurality
of setting recesses, and said slider means including
a plurality of projections engaging said setting
recesses for causing said blade to be securely
retained in one of said positions;
said slider means including resisting means
for frictionally resisting a free movement of said
blade during a cutting operation;
said resisting means including a resilient
member for abutting said first surface when said
blade is in said cutting position;
said handle including at least one tapered
surface positioned adjacent said blade such that said
resilient member contacts said tapered surface and is
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forced toward said blade when said blade is switched
from said storage position to said cutting position;
wherein said blade has a generally disc
shape and is rotatably mounted on said slider means,
and wherein said handle further includes a platform
extending from an end of said handle and supporting
the blade for rotation thereon.
Brief Description of the Drawings
Figure 1 is a plan view of a rotary disc blade
cutter, showing the blade retracted according to a
first embodiment of the present invention;
Figure 2 is a near plan view of the cutter of Figure
l;
Figure 3 is an enlarged partially broken plan view of
the rotary disc blade of Figure 1, illustrating a
slider in engagement with a handle;
Figure 4 is a cross-sectional view of the cutter
taken along line IV-IV in Figure 1;
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Figure 5 is a side view of the cutter showing the blade in a
protracted position;
Figure 6 is a partially broken plan view of the cutter of Figure
5;
Figure 7 is a cross-sectional view of the cutter taken along line
VII - VII in Figure 5;
Figure 8 is a side view of a cutter having a straight cutting
edge shown protracted according to a second embodiment of the
present invention; and
Figure 9 is a cross-sectional side view taken along line IX - IX
in Figure 8.
Description of the Preferred Embodiments
A preferred first embodiment of a rotary cutter according to the
present invention, will now be described with reference to
Figures 1 through 7.
As illustrated in Figure 1, the cutter includes a generally
elongated handle which is made of synthetic resin. An elongated
groove 2 guides a slider 3 along the front surface of the handle
1. An aperture B is formed in the handle 1, for hooking the
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cutter when it is not in use. When the slider 3 is manually
slid, the slider 3 is guided by the inner peripheral edge of the
groove 2 along length of the handle 1.
The distal end of the handle 1 includes an enlarged platform 4
which supports a disc blade 8. The platform 4 has a rear
generally flat surface. One surface of the platform 4 is
designated as an upper surface 4b, and engages the disc blade.
As shown in Figure 3, the upper surface 4b has a slot 5 and a
bore 6. The slot 5 and the bore 6 are adjacent to each other,
and are located along the sliding direction of the slider 3. The
bore 6 is positioned closer to the peripheral edge of the
platform 4. A relatively inclined tongue 7 is formed at the
distal end of the slot 5. The distal end of the tongue 7 is most
inclined than its proximal end, and is closer to the front
surface 4b.
The disc blade 8 is rotatably supported on the front surface 4b,
and has an orbicular peripheral cutting edge 8a. When the cutter
is not in use, the disc blade 8 is retracted so that the cutting
edge 8a is securely held within an arc shaped peripheral edge 4c
of the platform 4. As shown in Figures 5 through 7, when the
cutter is in use, a portion of the cutting edge 8a is caused to
protrude beyond the peripheral edge 4c by the slider 3.
The slider 3 is made of a synthetic resin. As shown in Figure
4, the slider 3 is integrally formed with a generally thin
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rectangularly shaped base 9, and a generally short finger grip
10. The base 9 is disposed on the rear surface of the platform
4 with the slider 3 placed in the groove 2. The finger grip 10
is easily accessible by the user. When the finger grip 10 is
pressed, it is bent toward the rear surface direction. When the
pressure is released, the elastic finger grip 10 returns to its
original position.
A nut 11 engages the base 9, and is securely fastened to the
central section of the disc blade 8, through the bore 6 of the
platform 4. A spring washer 12 is mounted on the upper surface
of the disc blade 8. A threaded bolt 13 is inserted in the
spring washer 12, and the disc blade 8 is coupled to the nut 11.
Therefore, the disc blade 8 is securely fastened against the
upper surface 4b by the spring washer 12. The disc blade 8 may
rotate steadily around the axis of the nut 11.
A cantilevered elastic projection 14 extends from the base 9 of
the slider 3, and projects outwardly toward the distal end of the
disc blade 8. It is inserted into the slot 5 of the platform 4,
and is disposed within the inner side of the disc blade 8. A tip
14a is used to apply pressure to the blade 8, is formed at the
distal end of the cantilevered projection 14, and engages the
tongue 7.
As shown in Figure 1, the finger grip 10 includes a pair of
projections 15 for positioning the blade 8. A pair of recesses
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16 and 17 engage the projections 15 for locking the blade into
positlon .
As shown in Figures 1 though 4, when the cutter is not in use,
the projections 15 of the finger grip 10 are inserted in the
first recess 16, so that the orbicular peripheral cutting edge
8a of the disc blade 8 is retracted and is securely held within
the arc shaped peripheral edge 4c of the platform 4. The tip 14a
of the slider 3 is then disengaged from the tongue 7. Therefore,
the tip 14a does not contact the disc blade 8.
When the cutter is in use, the finger grip 10 of the slider 3 is
pushed forward so as to disengage the projections 15 from the
first recess 16. As shown in Figures 5 through 7, when the
finger grip 10 is slid toward the platform 4 and the finger grip
10, is released the finger grip 10 returns to its original shape.
Consequently, the projections 15 engage the second recess 17.
The nut 11 and the threaded bolt 13 together with the base 9 of
the slider 3 are moved toward the platform 4 along the bore 6,
so that the orbicular peripheral cutting edge 8a of the disc
blade 8 protrudes beyond the peripheral edge 4c.
When cantilevered projection 14 of the slider 3 moves toward the
distal end of the platform 4, the tip 14a contacts the tongue 7.
Therefore, the tip 14a contacts the disc blade 8. The tip 14a
applies frictional pressure to the disc blade 8 in the direction
indicated by the arrow A, as shown in Figure 7. As a result, the
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frictional force applied to the disc blade 8 is significantly
increased when the disc blade 8 rotates.
When the cutter is in use, the finger grip 10 of the slider 3 is
moved toward the distal end of the platform 4, as previously
described. Therefore, the orbicular peripheral cutting edge 8a
of the disc blade 8 protrudes beyond the peripheral edge 4c. The
blade 8 is pressed against the material to be cut, and pressure
is applied to the handle 1 for causing the blade 8 to cut through
the material.
According to the first embodiment of the present invention, the
cantilevered elastic projection 14 is arranged on the slider 3.
When the cutter is in use, the cantilevered elastic projection
14 presses against the disc blade 8. Therefore, the appropriate
rotational friction force can be applied to the disc blade 8 by
means of the slider 3, without the use of a new part.
A second embodiment of the rotary disc blade cutter according to
the present invention will now be described with reference to
Figures 8 and 9, with specific focus on the differences between
the two embodiments.
A blade 28 has a straight cutting edge 28a. An opening 18 is
arranged at the distal end of a handle 21. The opening 18
communicates with a groove 22. The blade 28 is inserted into the
handle 21 through the opening 18. A projection 19 is arranged on
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a base 29 of a slider 23. The base section of the blade 28 is
inserted into the projection 19. Therefore, the slider 23 and
the blade 28 can be integrally moved.
The operation of the cutter will now be described. The slider
23 is moved toward the distal end by means of a finger grip 30,
so that the blade 28, which is retracted into the groove 22 of
the handle 21, is caused to protrude beyond the opening 18. The
distance traveled by the slider 23 controls the length of the
blade 28 protruding beyond the handle 21, or retracted therein.
When the cutter is in use, a tip 34a of a cantilevered elastic
projection 34 of the slider 23 is pressed by a tongue 27. The
tongue 27 is pressed against the blade 28 at an inner surface of
the opening 18 of the handle 21. As a result, the blade 28 is
pressed against the inner surface of the opening 18, so that the
sway of the blade 28 is significantly reduced.
The present invention can be used in conjunction with a plurality
of blades with various shapes, other than those described in the
present specification.
Although only two embodiments of the present invention have been
described, it should become apparent to those skilled in the art
that the present invention may be embodied in many other specific
forms without departing from the scope of the invention.
