Note: Descriptions are shown in the official language in which they were submitted.
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STAPLER AND STAPLE CARTRIDGE
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to a staple cartridge
containing therein a staple blank strip which is formed of
a number of straight staple blanks, each being a straight
short wire to be bent into a staple, connected side by side
into a strip of a length, and a stapler on which such a
staple cartridge is removably mounted.
Description of the Related Art
There has been known an electric stapler in which,
as shown in Figure 16, a staple cartridge 402 containing
therein a staple blank strip 401 which is formed of a
number of straight staple blanks 400 connected side by side
into a strip of a length is removably mounted on a stapler
body, a leading end portion of the staple blank strip 401
extending outside the staple cartridge 402 is fed in the
direction of arrow 404 into a retainer channel 409a of a
forming block 409 by a feeding mechanism, the frontmost
staple blank 401a held in the retainer channel 402 is
formed into a staple of a channel shape by a stroke (arrow
406) of a driver 405 and a former 410, and the staple is
struck into a sheet stack by a further stroke of the driver
405.
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As shown in Figure 17, a staple sensor 501 disposed
at a predetermined distance from the frontmost staple blank
401a detects the trailing end of the staple blank strip
401, the staple cartridge 402 is replaced with a new one
and the consumed staple cartridge is discarded.
However since the staple sensor 501 is disposed at
a predetermined distance from the frontmost staple blank
401a, there still remain a certain number of staple blanks
in the cartridge 402 at the time the staple sensor 501
detects the trailing end of the staple blank strip 401.
Accordingly when the staple cartridge 402 is replaced
immediately after detection of the trailing end of the
staple blank strip 401 by the staple sensor 501, the staple
blanks remaining in the staple cartridge 402 are wasted.
Therefore normally the staple cartridge 402 is replaced
when stapling is performed a certain number of times after
detection of the trailing end of the staple blank strip 401
by the staple sensor 501.
However since the cartridge 402 is provided with a
retainer spring 403 in order to prevent reverse feed of the
staple blank strip 401 as shown in Figure 17, a fraction of
the staple blank strip 401 remaining in the old cartridge
is left in the stapler body if the old cartridge is
replaced with a new one after the trailing end of the
staple blank strip 401 passes the retainer spring 403.
When a new staple cartridge is mounted on the stapler body
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in this state, the arrangement of the staple blanks is
broken in the stapler, which can result in defective
stapling and/or staple jamming.
In order to avoid this problem, conventionally, the
trailing end portion of the staple blank strip 401 is bent
upward to form a stopper portion 401' and an engagement
portion 403' adapted to be engaged with the stopper portion
401' on the staple blank strip 401 is provided on the
retainer spring 403 as shown in Figure 17. With this
arrangement, when the stopper portion 401' on the trailing
end of the staple blank strip 401 is brought into
engagement with the engagement portion 403' while stapling
is continued after detection of the trailing end of the
staple blank strip 401 by the staple sensor 501, feed of
the staple blank strip 401 is mechanically prevented. See
Japanese Patent Publication No. 6(1994)-9792.
Thus conventionally the staple cartridge is
replaced when the amount of staple blanks remaining in the
cartridge is reduced to a predetermined value and the
consumed cartridge is discarded anyway.
However since the cartridge casings are formed of
synthetic resin, the disposal of the cartridges is
difficult and leads to wastage of resources. On the other
hand, recovering the cartridges from users and refilling
the cartridges, or recycling the cartridges takes a lot of
labor and adds to cost of products.
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Thus it is desired that the staple cartridge can be
refilled on the spot. However this attempt will encounter
the following difficulties.
(1) Since the staple cartridge is provided with a
retainer spring 403 in order to prevent reverse feed of the
staple blank strip 401, a refill staple blank strip 401
cannot be inserted in the reverse direction into the casing
through the outlet port.
(2) Since the stopper portion 401' is formed on
the trailing end of the staple blank strip 401 in order
prevent a residual fraction of the staple blank strip 401
from being left in the stapler, the fraction of the staple
blank strip 401 left in the cartridge case cannot be
removed through the outlet port.
Accordingly, at present, refill of the staple
cartridge necessarily involves disassembly and reassembly
of the cartridge case.
In view of the foregoing observations and
description, the primary object of the present invention is
to provide a staple cartridge which can be refilled with a
staple blank strip without disassembly of the cartridge
casing even if the staple cartridge is provided with a
retainer spring and/or the staple blank strip is provided
with a stopper portion at its trailing end.
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DISCLOSURE OF THE INVENTION
In order to accomplish the above object, the
present invention has the following arrangement.
In accordance with the invention defined in Claim
1, there is provided a stapler comprising a staple
cartridge which consists of a casing and a staple blank
strip contained in the casing and is removably mounted on a
stapler body, a staple detecting means which detects that
the amount of staple blanks remaining in the casing becomes
a predetermined value, a staple drive means which bends
each of the staple blanks in the staple blank strip into a
staple in sequence from the leading end of the staple blank
strip and drives the staple into a sheet stack to be
stapled, a staple blank strip feed means which feeds the
staple blank strip to the staple drive means, and a
clinching means which bends the ends of the staple driven
into the sheet stack, wherein
the staple blank strip is provided with a stopper
portion at the trailing end portion thereof,
and the casing of the staple cartridge is provided
with
an engagement portion which is disposed forward of
a position where the staple detecting means detects that
the amount of staple blanks remaining in the casing is
reduced to a predetermined value and is brought into
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abutment against the stopper portion on the staple blank
strip to prevent further feed of the staple blank strip,
a reverse preventing means which is disposed
between the leading end of the casing and the engagement
portion and prevents the staple blank strip from being
reversed, and
an openable cover which opens a part of the casing
behind a position between the leading end of the casing and
the engagement portion so that the staple blank strip can
be replaced.
In the invention of Claim 1, a fraction of the
staple blank strip does not remain in the stapler and is
removed together with the casing by virtue of engagement of
the engagement portion with the stopper portion when the
staple cartridge is removed from the stapler after stapling
of a certain number of times after detection of the
trailing end of the staple blank strip by the staple
sensor. When the openable cover is opened, the remaining
fraction of the staple blank strip can be disengaged from
the reverse preventing means and/or the engagement portion
and removed from the casing. Accordingly the consumed
staple cartridge can be reused without discarding the
cartridge by refilling the casing with a new staple blank
strip.
A stapler in accordance with the invention defined
in Claim 2 is basically the same as that of the invention
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defined in Claim 1 except that the casing is provided with
an openable cover which opens a part of the casing behind
the leading end of the casing, in place of the cover which
opens a part of the casing behind a position between the
leading end of the casing and the engagement portion. In
the stapler of the invention defined in Claim 2, the
openable cover gives access to the reverse preventing means
and the engagement portion, and accordingly the remaining
fraction of the staple blank strip can be removed by
opening the cover and the cartridge casing can be refilled
with a new staple blank strip.
A stapler in accordance with the invention defined
in Claim 3 is basically the same as that of the invention
defined in Claim 1 except that the casing is provided with
an openable cover which opens a part of the casing behind a
position between the leading end of the casing and the
reverse preventing means, in place of the cover which opens
a part of the casing behind a position between the leading
end of the casing and the engagement portion. Also in the
stapler of Claim 3, the openable cover gives access to the
reverse preventing means and the engagement portion, and
accordingly the remaining fraction of the staple blank
strip can be removed by opening the cover and the cartridge
casing can be refilled with a new staple blank strip.
A stapler in accordance with the invention defined
in Claim 4 is basically the same as that of the Claim 1
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except that the casing is provided with an openable cover
which opens a part of the casing behind a position between
the reverse preventing means and the engagement portion, in
place of the cover which opens a part of the casing behind
a position between the leading end of the casing and the
engagement portion. In the stapler of this aspect, the
openable cover gives access to the engagement portion, and
accordingly though the remaining fraction of the staple
blank strip is held by the reverse preventing means, it can
be removed by cutting the stopper portion at the trailing
end thereof and drawing the fraction in the direction of
feed of the staple blank strip to the stapler. Then the
cartridge casing can be refilled with a new staple blank
strip.
In the staplers of Claims 1 to 4, the openable
cover may be hinged to the casing body at the rear edge of
the opening which the openable cover closes and opens
(claim 5), may be mounted on the casing body to be slidable
in the longitudinal direction of the casing body (Claim 6),
may be hinged to the casing body at a side edge of the
opening (Claim 7), or may be mounted on the casing body to
be slidable in the transverse direction of the casing body
Claim 8).
It is preferred that the casing be provided with a
locking means for locking the cover to the casing body.
(Claim 9)
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Specifically the casing body is formed of
transparent synthetic resin and the reverse preventing
means is formed of a metal spring (Claim 10). The staple
drive means may comprise, for instance, a driver, and a
pair of drive arms which are connected to opposite sides of
the driver and move up and down the driver, and a motor
which is disposed on the clinching means side and drives
the drive arms to move up and down the driver (Claim 11).
Further it is preferred that the staple drive means and the
clinching means be connected to each other by a pivot shaft
to be rotatable relative to each other and the pivot shaft
also functions as a driving force transmission shaft for
transmitting the driving force to the drive arms and as a
pivot shaft on which a lever for fixing the staple
cartridge is supported for rotation. (Claim 12) This
arrangement is advantageous in simplifying the structure of
the stapler and reducing the overall size of the stapler.
It is preferred that the clinching means be provided with a
stopper member for preventing a jammed staple from entering
the inside of the stapler. (Claim 13)
Claims 14 to 25 are inventions of staple cartridge
itself.
In accordance with the invention of Claim 14, there
is provided a staple cartridge which comprises a casing and
a staple blank strip contained in the casing and is
removably mounted on a stapler so that the staple blanks of
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the staple blank strip is formed into a staple and driven
into a sheet stack to be stapled one by one by operation of
the stapler, where the improvement comprises that
the staple blank strip is provided with a stopper
portion at the trailing end portion thereof,
and the casing is provided with
an engagement portion which, when the amount of
staple blanks remaining in the casing is reduced to a
predetermined value, is brought into abutment against the
stopper portion on the staple blank strip to prevent
further feed of the staple blank strip,
a reverse preventing means which is disposed
between the leading end of the casing and the engagement
portion and prevents the staple blank strip from being
reversed, and
an openable cover which opens a part of the casing
behind a position between the leading end of the casing and
the engagement portion so that the staple blank strip can
be replaced.
In the invention of Claim 14, a fraction of the
staple blank strip does not remain in the stapler and is
removed together with the casing by virtue of engagement of
the engagement portion with the stopper portion when the
staple cartridge is removed from the stapler after stapling
of a certain number of times after detection of the
trailing end of the staple blank strip by the staple
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sensor. When the openable cover is opened, the remaining
fraction of the staple blank strip can be disengaged from
the reverse preventing means and/or the engagement portion
and removed from the casing. Accordingly the consumed
staple cartridge can be reused without discarding the
cartridge by refilling the casing with a new staple blank
strip.
A staple cartridge in accordance with the invention
of Claim 15 is basically the same as that of Claim 14
except that the casing is provided with an openable cover
which opens a part of the casing behind the leading end of
the casing, in place of the cover which opens a part of the
casing behind a position between the leading end of the
casing and the engagement portion. In the staple cartridge
of Claim 15, the openable cover gives access to the reverse
preventing means and the engagement portion, and
accordingly the remaining fraction of the staple blank
strip can be removed by opening the cover and the cartridge
casing can be refilled with a new staple blank strip.
A staple cartridge of Claim 16 is basically the
same as that of Claim 14 except that the casing is provided
with an openable cover which opens a part of the casing
behind a position between the leading end of the casing and
the reverse preventing means in place of the cover which
opens a part of the casing behind a position between the
leading end of the casing and the engagement portion. Also
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in the staple cartridge of Claim 16, the openable cover
gives access to the reverse preventing means and the
engagement portion, and accordingly the remaining fraction
of the staple blank strip can be removed by opening the
cover and the cartridge casing can be refilled with a new
staple blank strip.
A staple cartridge Claim 17 is basically the same
as that of Claim 14 except that there is provided an
openable cover which opens a part of the casing behind a
position between the reverse preventing means and the
engagement portion in place of the cover which opens a part
of the casing behind a position between the leading end of
the casing and the engagement portion. In the staple
cartridge of Claim 17, the openable cover gives access to
the engagement portion, and accordingly though the
remaining fraction of the staple blank strip is held by the
reverse preventing means, it can be removed by cutting the
stopper portion at the trailing end thereof and drawing the
fraction in the direction of feed of the staple blank strip
to the stapler. Then the cartridge casing can be refilled
with a new staple blank strip.
In accordance with the invention of Claim 18, there
is provided a staple cartridge comprising a casing and a
staple blank strip contained in the casing, the casing
being provided with a circular chamber portion, an
extension which extends tangentially to the chamber
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portion, and a retainer spring which is disposed in the
extension and prevents the staple blank strip from being
reversed, wherein the improvement comprises that
the casing is provided with an openable cover which
can be opened along a parting line on the bottom of the
extension between the leading end of the casing and the
retainer spring to open a part of the casing behind the
parting line, thereby permitting replacement of the staple
blank strip. In the staple cartridge of Claim 18, the
aforesaid stopper portion at the trailing end of the staple
blank strip and the engagement portion to be brought into
engagement with the stopper portion may be provided or need
not be provided. Also in the staple cartridge, the staple
blank strip can replaced by opening the openable cover and
releasing the fraction of the staple blank strip from the
retainer spring.
In the staple cartridges of Claims 14 to 18, the
openable cover may be hinged to the casing body at the rear
edge of the opening which the openable cover closes and
opens (Claim 19), may be mounted on the casing body to be
slidable in the longitudinal direction of the casing body
(Claim 20), may be hinged to the casing body at a side edge
of the opening (Claim 21), or may be mounted on the casing
body to be slidable in the transverse direction of the
casing body (Claim 22). It is preferred that the casing be
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provided with a locking means for locking the cover to the
casing body (Claim 23).
For example, the locking means may comprise a lock
arm which is formed on one of the casing body and the
openable cover and is wedge-shaped in cross-section and a
lock bearing having a recess complementary to the lock arm
in shape which is formed on the other of the casing body
and the openable cover so that the lock arm and the lock
bearing are brought into engagement with each other when
the openable cover is closed (Claim 24). Since the casing
can be resiliently deformed in the direction of width of
the staple blank strip, when the cover is closed and
pressed against the casing body, the lock arm is slid on
the inner surface of the lock bearing into engagement
therewith. However when there remains a large amount of
staple blank strip in the casing, the staple blank strip
suppresses resilient deformation of the casing and it is
difficult to disengage the lock arm from the lock bearing.
Accordingly, an event such that the cover is opened by
accident before the staple blank strip is consumed up can
be avoided.
It is preferred that the casing is formed of
transparent synthetic resin and the reverse preventing
means be formed of a metal spring (Claim 25).
Specifically the present invention results in the
following excellent effects.
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1) In the inventions of Claims 1 and 14, the staple
blank strip is provided with a stopper portion at the
trailing end portion thereof, and the casing is provided
with an engagement portion which is brought into abutment
against the stopper portion on the staple blank strip to
prevent further feed of the staple blank strip and a
reverse preventing means which is disposed between the
leading end of the casing and the engagement portion and
prevents the staple blank strip from being reversed. The
casing is further provided with an openable cover which
opens a part of the casing behind a position between the
leading end of the casing.
Accordingly, in the invention of Claim 1 or 14,
when the openable cover is opened, the remaining fraction
of the staple blank strip can be disengaged from the
reverse preventing means and/or the engagement portion and
removed from the casing. Accordingly the consumed staple
cartridge including the retainer spring and the engagement
portion can be reused without discarding the cartridge by
removing the remaining fraction of the staple blank strip
and refilling the casing with a new staple blank strip.
Further the remaining fraction of the staple blank
strip does not remain in the stapler and is removed
together with the casing by virtue of engagement of the
engagement portion with the stopper portion when the staple
cartridge is removed from the stapler after stapling of a
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certain number of times after detection of the trailing end
of the staple blank strip by the staple sensor.
2) In the inventions of Claims 2 and 15, the
casing is provided with an openable cover which opens a
part of the casing behind the leading end of the casing.
The openable cover gives access to the reverse preventing
means and the engagement portion, and accordingly the
remaining fraction of the staple blank strip can be removed
by opening the cover and the cartridge casing can be
refilled with a new staple blank strip.
3) In the inventions of Claims 3 and 16, the
casing is provided with an openable cover which opens a
part of the casing behind a position between the leading
end of the casing and the reverse preventing means. The
openable cover gives access to the reverse preventing means
and the engagement portion, and accordingly the remaining
fraction of the staple blank strip can be removed by
opening the cover and the cartridge casing can be refilled
with a new staple blank strip.
4) In the inventions of Claims 4 and 17, the
casing is provided with an openable cover which opens a
part of the casing behind a position between the leading
end of the casing and the engagement portion. By opening
the cover, the remaining refraction of the staple blank
strip can be removed by cutting the stopper portion at the
trailing end thereof and drawing the fraction in the
16
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direction of feed of the staple blank strip to the stapler.
Then the cartridge casing can be refilled with a new staple
blank strip.
5) The effect that the cartridge casing can be
refilled with a new staple blank strip can be obtained also
in the staple cartridges where only the reverse preventing
means is provided (Claim 18), the openable cover is hinged
to the casing body at the rear edge of the opening which
the openable cover closes and opens (Claims 5 and 19), the
openable cover is mounted on the casing body to be slidable
in the longitudinal direction of the casing body (Claims 6
and 20), the openable cover is hinged to the casing body at
a side edge of the opening (Claims 7 and 21), or the
openable cover is mounted on the casing body to be slidable
in the transverse direction of the casing body (Claims 8
and 22).
6) In the inventions of Claims 9 and 23, since the
casing is provided with a locking means for locking the
cover to the casing body, the openable cover and the casing
body are integrated handling of the staple cartridge is
facilitated.
7) In the invention of Claim 24, the locking means
comprises a lock arm which is formed on one of the casing
body and the openable cover and is wedge-shaped in cross-
section and a lock bearing having a recess complementary to
the lock arm in shape which is formed on the other of the
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casing body and the openable cover so that the lock arm and
the lock bearing are brought into engagement with each
other when the openable cover is closed. Since the casing
can be resiliently deformed in the direction of width of
the staple blank strip, when the cover is closed and
pressed against the casing body, the lock arm is slid on
the inner surface of the lock bearing into engagement
therewith. However when there remains a large amount of
staple blank strip in the casing, the staple blank strip
suppresses resilient deformation of the casing and it is
difficult to disengage the lock arm from the lock bearing.
Accordingly, an event such that the cover is opened by
accident before the staple blank strip is consumed up can
be avoided.
8) According to the inventions of Claims 10 to 13
and 25, arrangements easy to realize can be obtained.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a side view showing a staple cartridge
in accordance with a first embodiment of the present
invention with the cover opened,
Figure 2 is a perspective view of a staple blank
strip employed in the staple cartridge,
Figure 3 is a side view showing the cover of the
staple cartridge,
Figure 4 is a cross-sectional view taken along line
IV-IV in Figure 3,
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Figure 5 is a side view of a stapler in accordance
with an embodiment of the present invention,
Figure 6 is a plan view of the stapler,
Figure 7 is a front view of the stapler,
Figure 8 is a cross-sectional view of the stapler,
Figure 9 is a cross-sectional view showing the head
unit of the stapler,
Figure 10 is an enlarged side view showing a part
of the stapler,
Figures 11 to 15 are views respectively showing
staple cartridges in accordance with second to sixth
embodiments of the present invention,
Figure 16 is a view for illustrating operation of a
stapler and a staple cartridge according to a prior art,
and
Figure 17 is a view which schematically shows the
arrangement of a conventional staple cartridge.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In Figures 1 and 2, a staple cartridge 200 in
accordance with a first embodiment of the present comprises
a casing 210 and a staple blank strip 300 contained in the
casing 210. The staple blank strip 300 is of a well known
type and comprises a number of straight staple blanks 301,
each being a straight short wire to be bent into a staple,
bonded to an adhesive tape 302 at their central portions
side by side into a strip of a length a shown in Figure 2.
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The trailing end portion of the staple blank strip 300 is
bent to form a stopper portion 303.
The casing 210 is formed of transparent synthetic
resin and is openable to permit replacement of the staple
blank strip 300. The casing 210 contains the staple blank
strip 300 so that the staple blank strip 300 can be drawn
out to feed the leading end of the staple blank strip 300
to a stapling position, that is, into a retainer channel of
a forming block.
More specifically the casing 210 comprises a
circular chamber portion 201 in which a rolled portion 304
of the staple blank strip 300 is contained and an extension
202 which extends tangentially to the chamber portion 201
and through which the leading end portion 305 unrolled from
the roller portion 304 of the staple blank strip 300 is
drawn out.
The extension 202 comprises a bottom plate 203, a
pair of opposed side wall portion 204 erected from opposite
side edges of the bottom plate 203, and a pair of guide
protrusions 205 formed on the inner surfaces of the side
wall portions 204 and a staple blank strip feed passage 206
is formed by the bottom plate 203, the side wall portions
204 and the guide protrusions 205.
A projection 207 extends between the side wall
portions 204 at an intermediate portion of the extension
202 and a base of a retainer spring 208 in the form of a
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metal spring plate is fixed to the extension 202 at an
intermediate portion thereof. The projection 207 forms a
support of a feed spring 91 on the open end side. The
leading end portion of the retainer spring 208 presses the
staple blank strip at a predetermined pressure. An
engagement portion 209 which is adapted to be brought into
engagement with the stopper portion 303 on the trailing end
of the staple blank strip 300 to prevent feed of the staple
blank strip 300 is provided on the extension 202 behind the
leading end portion of the retainer spring 208. The
engagement portion 209 is positioned downstream of a staple
sensor 14 (reflective photodetector), for detecting the
trailing end of the staple blank strip 300, as seen in the
direction of feed of the staple blank strip 300 as shown in
Figure 9.
The casing 210 is divided into a body portion A and
an openable cover B in a position between the leading end
of the casing 210, i.e., the leading ends 202a of the
extension 202, and the engagement portion 209. The
openable cover B is hinged to the body portion A by a pivot
211 provided near the top of the chamber portion 201.
In this particular embodiment, the chamber portion
201 is divided along an off-centered line so that a larger
space of the chamber portion 201 is included in the body
portion A. The extension 202 is divided so that the side
wall portions 204, the guide protrusions 205, the
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projection 207 and the retainer spring 208 are on the body
portion side. In this particular embodiment, the front
half 203a of the bottom plate 203 is on the body portion
side and the rear half 203b of the bottom plate 203 is on
the openable cover side. The bottom plate 203 is cut into
the front and rear halves 203a and 203b along a line
forward of the retainer spring 208.
Further as shown in Figures 1, 3 and 4, a lock arm
212 which is wedge-shaped in cross-section is formed on
each side of the cover B near the center of the chamber
portion 201 and a lock bearing 213 having a wedge-shaped
recess is formed on each side of the body portion A near
the center of the chamber portion 201 so that the lock arms
212 and the lock bearings 213 are brought into engagement
with each other when the cover B is closed, thereby locking
the cover B to the body portion A. That is, since the
casing 210 can be resiliently deformed in the direction of
width of the staple blank strip 300, when the cover B is
closed and pressed against the body portion A, the lock
arms 212 are slid on the inner surface of the lock bearings
213 into engagement therewith while the body portion A is
slightly expanded outward. Since the lock arms 212 are
wedge-shaped in cross-section, though they can be slid on
the inner surface of the lock bearings 213 into engagement
therewith, it is difficult to deform inward the cover B to
disengage the lock arms 212 from the lock bearings 213 when
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there remains a large amount of staple blank strip 300 in
the casing 210. Accordingly, an event such that the cover
B is opened by accident when the staple cartridge 200 is
mounted on the stapler.
A stapler on which the staple cartridge 200 of this
embodiment is mounted will be described hereinbelow.
In Figures 5 to 10, the stapler 1 comprises a frame
2, a head unit 3, a staple drive means 4 which bends each
of the staple blanks 301 in the staple blank strip 300 into
a staple in sequence from the leading end of the staple
blank strip 300 and drives the staple into a sheet stack to
be stapled, a clinching means 5 which bends the ends of the
staple driven into the sheet stack, and a staple blank
strip feed means 6 which feeds the staple blank strip 300
to the staple drive means 4.
The frame 2 comprises a hollow base portion 20 and
a pair of side walls 22 extending upward from opposite
sides of the base portion 20. An anvil 21 which forms the
clinching means 5 is supported on an upper front portion of
the base portion 20. A body 30 of the head unit 3 is
disposed between the side walls 22 and hinged to the base
portion 20 at its rear end to be rotatable up and down by a
pivot shaft 31. That is, the staple drive means 4 and the
clinching means 5 are connected to be rotatable relative to
each other about the pivot shaft 31.
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A front outer cover 40 is provided forward of the
body 30 and a former 70 for bending a staple blank 301 into
a channel-shaped staple is disposed between the body 30 and
the front outer cover 40. A forming block (bending block)
60 extends through the front outer cover 40 and is pressed
by a spring 50. The body 30, the front outer cover 40, the
former 70, the forming block 60 and the spring 50 form the
head unit 3.
The body 30 comprising a receiving base portion 32
for receiving the extension 202 of the staple cartridge
200, an erected portion 34 which extends upward from a
front end portion of the receiving base portion 32, a top
portion 35 which extends over the receiving base portion 32
from the top of the erected portion 34 and a guide pole 36
erected on the top portion 35. An upper head portion 81 of
a driver 80 disposed above the body 30 is fitted on the
guide pole 36 to be movable up and down. The driver 80
comprises the upper head portion 81, a pusher claw 84 and a
driving blade 86. The upper head portion 81 is pushed and
pulled by a pair of drive arms 55 on opposite sides thereof
to be rotated about the pivot shaft 31.
A one-cycle drive motor 51 which can rotate in both
the regular and reverse directions and drives the drive
arms 55 to move up and down the driver 80 is disposed on an
rear portion of the base portion 20 on which the anvil 21
is supported.
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The drive motor 51, the drive arms 55 and the
driver 80 form the staple drive means 4. A pinion is fixed
to the output shaft of the drive motor 51 and a pair of
large gears 54 are respectively mounted for rotation on the
outer surface of the side walls 22. Rotation of the drive
motor 51 is transmitted to the large gears 54 through gears
52 and 53. The gear 53 is mounted on the pivot shaft 31
for the body 30 and accordingly the pivot shaft 31 doubles
as a drive shaft for transmitting driving force to the
drive arms 55. Further also a cartridge lock lever 101 is
mounted for rotation on the pivot shaft 31. Thus the
stapler can be simple in structure and small in size.
The drive arms 55 are mounted for rotation on the
side walls 22 by an arm shaft 56. Each of the drive arms
55 is provided with an elongated opening 55a having a cam
surface 57 in one end portion thereof and a slit 55b in the
other end portion thereof. A drive roller 58 erected on
the outer side of the large gear 54 is in engagement with
the cam surface 57 of the opening 55a. When the large gear
54 is rotated, the slit side end portion of the drive arm
55 is rotated up and down by way of engagement of the
roller 58 with the cam surface 57, whereby the driver 80 is
moved up and down to press downward and lift up the driving
blade 86. The arm shaft 56 extends through elongated
holes, which are long in the vertical direction, formed in
the side walls 22 to be slightly movable up and down. The
CA 02238012 1998-0~
arm shaft 56 is urged downward by a coiled spring 59 tensed
between the arm shaft 56 and an ear 22a formed on the side
wall 22.
In order to form a staple blank strip feeding means
6, a feeder 90 which is provided with the feed spring 91
and a feeding claw 92 is disposed adjacent to the erected
portion 34 of the body 30. The feeder 90 is supported for
rotation on a shaft 93. The forming block 60 having a
retainer channel 64 for holding the staple blank 301 is
disposed in front of an opening 100 in the erected portion
34 to be movable left and right as seen in Figure 9. The
forming block 60 is urged toward the erected portion 34 by
the spring 50.
A staple cartridge 200 is removably mounted
adjacent to the feeder 90. As described above, the staple
cartridge 200 is provided with the projection 207, which
forms a support of the feed spring 91 on the open end side,
on the extension 202 thereof and the retainer spring 208
for holding the staple blank strip 300.
The former 70 is disposed adjacent to the driving
blade 86 and is moved downward by a predetermined distance
pushed by the pusher claw 84 on the driver 80 when the
driver 80 is moved downward. The former 70 is provided
with a projection 75, and when the driving blade 86 is
moved upward, the projection 75 is brought into engagement
with an elongated hole 82 in the driving blade 86, whereby
CA 02238012 1998-0~
the former 70 is lifted. The pusher claw 84 is disengaged
from the former 70 after pushing downward the former 70 by
a predetermined distance.
The projection 75 on the former 70 pushes a cam
surface 94 on the feeder 90 when the former 70 is moved
downward, whereby the feeder 90 is rotated
counterclockwisely in Figure 9 about a shaft 93 to move the
feeding claw 92 rearward to a retracted position. When the
former 70 is moved upward and the feeder 90 is released,
the feeder 90 is returned to its advanced position under
the force of the feed spring 91 and the feeding claw 92
feeds the staple blank strip 300 by a predetermined
distance.
When the large gears 54 are rotated in the same
phase by the drive motor 51, the roller 68 (Figure 5) rolls
on the cam surface 57 and the drive arms 55 are rotated
about the arm shaft 56, whereby the slit side end portion
of each drive arm 55 is rotated downward to move downward
the head portion 81 of the driver 80. Then the driving
blade 86 is pushed downward and the body 30 is rotated
downward about the pivot shaft 31 toward the anvil 21. As
a result, the body 30 and the anvil 21 are opposed to each
other in a stapling position intervening therebetween a
sheet stack to be stapled.
As shown in Figures 8 and 10, a stopper member 23
in the form of a rectangular pole extends transversely on
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the upper surface of the anvil 21 behind the throat of the
stapler into which the sheet stack to be stapled is
inserted. The stopper member 23 prevents a staple from
entering the inside of the stapler (the right side in
Figure 10) when stapler jamming takes place.
(1) Normal action of one cycle
The normal action of one cycle of the stapler will
be described hereinbelow. For the purpose of
simplification of description, it is assumed that the
staple blank strip 300 in the staple cartridge 200 has been
fed to the forming block 60 through the opening 100 in the
erected portion 34 by the feeding claw 92 of the feeder 90
and the middle portion of the frontmost staple blank 301
has been held in the retained channel 64 of the forming
block 60.
In Figure 5 to 10, torque of the drive motor 51 is
reduced in speed by the gears 52 and 53 and is transmitted
to the large gears 54. When the large gears 54 are rotated
by a predetermined angle corresponding to the home
position, the drive arms 55 start to push downward the
driver 80 and the body 30 begins to move downward away from
the home position. When the body 30 is brought into
abutment against a sheet stack on the base portion 20, the
driving blade 86 is moved downward relative to the body 30
and the former 70 is moved downward pushed by the pusher
claw 84 to bend the end portions of the straight staple
28
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blank 301 held on the forming block 60 and form the staple
blank 301 into a channel-shaped staple. Further the
driving blade 86 is pushed downward and the pusher claw 84
is disengaged from the former 70 and only the driving blade
86 is further moved downward. The driving blade 86 is
brought into abutment against an inclined surface of the
forming block 60 and further moved downward while
displacing the forming block 60 sideways, thereby cutting
the frontmost staple blank 301, which has been formed into
a staple, off the staple blank strip 300 in front of the
erected portion 34 and drives the staple into the sheet
stack. The position of the elements in this state will be
referred to as "clinching position" hereinbelow.
While the drive arms 55 and the body 30 stay in the
clinching position, a pair of clinch levers 24 hung
downward from the base portion 20 are pushed upward by
supports 25 from below and are displaced in the anvil 21 to
bend flat the end portions of the staple projecting through
the sheet stack. Each of the supports 25 is formed on one
end of a lever 26 which is in engagement with a cam surface
(not shown) on the large gear 54 at its the other end and
is rotated about a shaft 27 by the large gear 54 overcoming
the force of a spring plate 28.
Then the body 30 comes to be moved upward away from
the clinching position, which moves upward the driver 80
and the driving blade 86 to the home position. Further the
29
CA 02238012 1998-0~
drive arms 55 and the body 30 are returned to the home
position shown in Figure 5. Thus one cycle of stapling is
ended. The one cycle of stapling corresponds to one turn
of the larger gears 54. Though in this embodiment the
staple is bent in flat clinching, the staple may be
clinched in a well known glass clinching in the anvil 21.
When the driving blade 86 is returned to the home
position, that is, when the projection 75 on the former 70
is returned to the home position, the feeder 90 is rotated
clockwisely in Figure 9 under the resiliency of the feeder
spring 91 and the feeding claw 92 is moved forward from the
retracted position, whereby the next staple blank 301 of
the staple blank strip 300 is fed into the retainer channel
64 of the forming block 64 and preparation for the next
stapling is made.
(Replacement of the staple cartridge)
As shown in Figure 9, the staple sensor 14 is a
reflective sensor comprising a photo emitting element and a
photo receiving element disposed on the bottom 32a of the
receiving base portion 32 of the body 30. The staple
sensor 14 detects light reflected from the staple blank
strip 300 in the staple cartridge 200 through the
transparent casing 210 and constantly monitors existence of
the staple blank 301 and outputs an empty signal when the
staple blank 301 is consumed. However since the staple
sensor 14 is disposed at a distance from the forming block
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60, it detects, strictly speaking, that the staple blank
strip 300 is about to be consumed.
When the amount of staple blanks remaining in the
staple cartridge 200 is reduced to a predetermined value,
the trailing end of the staple blank strip 300 is detected
by the staple sensor 14. At this time, the consumed staple
cartridge 200 is removed from the stapler and is refilled
with a new staple blank strip 300.
Since the staple sensor 14 is disposed at a
distance from the leading end 202a of the staple cartridge
200, stapling can be continued until the stopper portion
303 on the trailing end of the staple blank strip 300 is
brought into abutment against the engagement portion 209
even after the staple sensor 14 detects the trailing end of
the staple blank strip 300.
Since the engagement portion 209 is disposed
upstream of the retainer spring 208, the stopper portion
303 is necessarily brought into abutment against the
engagement portion 209 before the trailing end of the
staple blank strip 300 passes the retainer spring 208 and
further feed of the staple blank strip 300 is mechanically
prevented. Accordingly, whenever the staple cartridge 200
is removed from the stapler 1, the fraction of the staple
blank strip 300 remaining in the staple cartridge 200 is
necessarily removed together with the staple cartridge 200
and is never left in the stapler 1. Accordingly, when the
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staple cartridge refilled with a new staple blank strip 300
is mounted on the stapler in this state, there never arises
a problem that the arrangement of the staple blanks left in
the stapler is broken and defective stapling and/or staple
jamming is caused.
When removing the staple cartridge 200 from the
body 30 of the stapler 1, the lock lever 101 is manually
clockwisely (in Figure 9) rotated about the pivot shaft 31
to disengage a locking claw lOla on the lever 101 from an
ear portion 214 on the rear end face of the casing 210.
After the staple cartridge 200 is removed from the
stapler 1, the openable cover B of the casing 210 is opened
about the pivot 211 as shown in Figure 1 after releasing
the lock arms 212 from the lock bearings 213 by deflecting
inward the central portions of the side walls of chamber
portion 201 on the cover side. When the cover B is opened,
the retainer spring 28 and the engagement portion 209 are
exposed from below. Since being fixed to the body portion
A of the casing 210, the retainer spring 208 cannot fall
off the body portion A. After the fraction of the staple
blank strip 300 remaining in the body portion A is removed,
the casing 210 can be refilled with a new staple blank
strip 300. The leading end portion 305 of the new staple
blank strip 300 is inserted into the staple blank strip
feed passage 206 formed by the front half 203a of the
bottom plate 203 and the guide protrusions 205.
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When the cover B is closed, the lock arms 212 and
the lock bearings 213 are brought into engagement with each
other thereby locking the cover B to the body portion A.
Since the lock arms 212 are wedge-shaped in cross-section
as shown in Figure 4, though they can be slid on the inner
surface of the lock bearings 213 into engagement therewith,
it is difficult to deform inward the cover B to disengage
the lock arms 212 from the lock bearings 213 after they are
once engaged with each other due to interference by the new
staple blank strip 300. Accordingly, an event such that
the cover B is opened by accident when the staple cartridge
200 is mounted on the stapler.
Further when the cover B is closed, the front half
203a of the bottom plate 203 on the body portion side and
the rear half 203b of the bottom plate 203 on the openable
cover side are mated together and the staple blank strip
feed passage 206 is formed again.
The refilled staple cartridge 200 is mounted on the
body 30 of the stapler 1 so that the leading end portion
202a of the staple blank strip feed passage 206 is fitted
in the opening 100 (Figure 9) of the body 30. Then the
lock lever 101 is manually rotated to bring the locking
claw lOla on the lever 101 into engagement with the ear
portion 214 on the rear end face of the casing 210, whereby
the staple cartridge 200 is correctly located relative to
the body 30. When the staple cartridge 200 is thus mounted
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on the stapler 1, the leading end portion 203c of the
bottom plate 203 terminates in the opening 100 of the body
30. The leading end portion 203c determines a reference
position when cutting the staple blank strip 300.
The stapler 1 feeds the leading end of the staple
blank strip 300 extending outward from the casing 210 into
the retainer channel 64 of the forming block by the feed
means 6, and bends the frontmost staple blank 301 of the
staple blank strip 300 into a staple and drives the staple
into the sheet stack by the driver 80.
(Other embodiments)
Though in the embodiment described above, the
bottom plate 203 is divided into the body side portion and
the cover side portion downstream of the retainer spring
208 so that the part of the casing 210 behind a position
between the leading end 202a of the casing 210 and the
retainer spring 208 is openable, the parting line may be
set in any position between the leading end 202a of the
casing 210 and the engagement portion 209, and the
engagement portion 209 may be disposed in any position in
the extension 202 of the casing 210.
In the staple cartridge in accordance with the
second embodiment of the present invention shown in Figure
11, the parting line of the bottom plate 203 is set
upstream of the retainer spring 208 so that the part of the
casing 210 behind a position between the retainer spring
34
CA 02238012 1998-0~
208 and the engagement portion 209 is openable about the
pivot 211. Though the fraction of the staple blank strip
300 remaining the staple cartridge 200 is held by the
retainer spring 208, the fraction can be removed by pulling
it in the direction of feed of the staple blank strip 300
after the stopper portion 303 on the trailing end of the
staple blank strip 300 is cut off. Since the stopper
portion 303 on the trailing end of the staple blank strip
300 is exposed when the cover B is opened, the stopper
portion 303 can be cut.
In the staple cartridge in accordance with the
third embodiment of the present invention shown in Figure
12, the whole bottom plate 203 is opened about the pivot
211. In this embodiment, since the retainer spring 208 and
the engagement portion 209 are both exposed when the cover
B is opened, removal of the fraction of the staple blank
strip 300 and refilling are facilitated.
Though in the preceding embodiments, the cover B is
hinged about an axis disposed on the rear side of the
casing 210, the cover B may be mounted on the casing body
in other various manners.
For example, in the staple cartridge in accordance
with the fourth embodiment of the present invention shown
in Figure 13, the openable cover B is opened and closed by
sliding the cover B relative to the casing body A in the
longitudinal direction of the casing 210.
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In the staple cartridge in accordance with the
fifth embodiment of the present invention shown in Figure
14, the openable cover B is hinged to one side of the
bottom of the casing body A by a pivot 215.
In the staple cartridge in accordance with the
sixth embodiment of the present invention shown in Figure
15, the openable cover B which covers the bottom of the
casing body A is opened and closed by sliding the cover B
relative to the casing body A in the transverse direction
of the casing 210.
Also the staple cartridges 200 of the second to
sixth embodiments may be provided with a locking mechanism
for locking the cover B to the casing body A.
