BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to an electric stapler for fastening
together a sheaf of documents or the like using a staple that punches holes in the
document sheaf and is clinched. It particularly relates to an electric stapler in
which a staple is simultaneously pressed by an arm and by a frame to punch holes
in the document sheaf and also has a structure that prevents the frame being deformed
from frequent use.
Staplers are extensively used as a tool for filing documents
and the like in the form of sheaves of sheets. Most staplers are manually operated,
but there are also electrically-operated staplers, devised to be used in place of
manual staplers for stapling of thick document sheaves requiring more strength.
Since they are electrically driven, electric staplers are able to perform binding
automatically, and are therefore convenient to use. A typical example of an electric
stapler technology is that disclosed in
Japanese Unexamined Patent Publication No. 2000-317861
EP-A-1 052 068
The electric stapler of this prior art has a structure
whereby, as a dispensing arm is driven by a motor in the downward direction of a
pressing member, a magazine frame moves downward at its front end under its own
weight, until the lower surface of the front end of the magazine frame touches the
upper surface of the object to be stapled. It is formed such that, when the pressing
member is moved to its lowest point, the dimension between the catch of a suspension
member and the support is a dimension such that the front end of the dispensing
arm can move due to movement of the pressing member so that a staple stored in the
magazine frame is pushed out from the dispensing outlet.
Also, the magazine frame has a structure comprising a case
provided with a staple storage area and a case cover that covers the upper surface
of the case, the structure being such that the loading of staples can be carried
out by pulling the case from the case cover at the front end of the magazine frame
in the case meeting area which is formed by the side wall in the lengthwise direction
of the case cover and the side surface in the lengthwise direction of the case,
in a long, mutually meshing groove and long protrusion.
Moreover, the constitution is such that a switch that closes
the electrical circuit of the motor upon contact with the edge of the object to
be stapled, which is inserted between the base and the front end of the magazine
frame, is provided on a moveable member that can be moved from the front end of
the magazine frame toward the back end.
Conventional electric staplers have a structure wherein
the switch for actuation itself moves from the front end to the back end. Since
the durability of the switch over long-term use is therefore poorer than that of
a fixed switch, conventional electric staplers are prone to breakage. Moreover,
the dimension between the catch of the suspension member and the support must be
one that permits the engagement of the pressing member, so it naturally must be
of a certain size. Also, the magazine frame is deformed by frequent use.
Therefore, a need has been felt for the development of
an electric stapler having a simple structure that is able to securely perform stapling.
SUMMARY OF THE INVENTION
The object of the present invention is to overcome the
foregoing problems by providing an electric stapler in which an arm pushes down
a staple stored in a magazine frame while at the same time the magazine frame swings
about a fulcrum to clamp the document sheaf through which the staple is driven to
bind the sheets, an elastic body is provided at a lower portion of the magazine
frame to return the magazine frame and arm to the original binding position, and
a deformation prevention member is affixed at the front end of the magazine frame
to prevent the magazine frame from becoming deformed due to frequent use.
For attaining this object, this invention provides an electric
stapler comprising: a case body, a drive section constituted by a rotary drive motor
and gears, a wiring board provided with electrical circuitry, a magazine frame that
stores staples, an arm that pushes, from above, staples stored in the magazine frame
to penetrate and staple a sheaf of documents or the like, wherein staples are pressed
down on a document sheaf under the weight of the magazine frame and staple penetration
and fastening is performed by the magazine frame and arm swing up and down about
fulcrums, with the arm pushing down on a staple stored in the magazine frame and
the magazine frame swinging about a fulcrum to press against the document sheaf,
an elastic body provided on the lower part of the magazine frame that urges the
magazine frame and arm back to an original document sheaf stapling position, and
a deformation prevention member provided on the front end of the magazine frame
to prevent the magazine frame from being deformed due to frequent use.
The features of the present invention will become apparent
from the following description made with reference to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
DESCRIPTION OF THE PREFERRED EMBODIMENT
- Figure 1 is a side view of the electric stapler of a preferred embodiment of
- Figure 2 is a cross-sectional side view of the magazine frame and arm of the
- Figure 3 is a cross-sectional side view of the magazine frame and arm prior
- Figure 4 is a cross-sectional side view of the magazine frame and arm prior
to staple penetration.
- Figure 5 is a cross-sectional side view of the magazine frame and arm during
Details of the electric stapler of the invention will now
be explained with reference to the drawings, in which Figure 1 is a side view of
the electric stapler, Figure 2 is a cross-sectional side view of the magazine frame
and arm, Figure 3 is a cross-sectional side view of the magazine frame and arm prior
to operation, Figure 4 is a cross-sectional side view of the magazine frame and
arm prior to staple penetration, and Figure 5 is a cross-sectional side view of
the magazine frame and arm during staple penetration.
As shown in Figure 1, the electric stapler of the invention
comprises a case body, a drive section, a wiring board, a magazine frame 20, an
arm 30, an actuating bar, and a fixed switch. A conventional case body, drive section,
wiring board, actuating bar and fixed switch may be used. The characterizing feature
of the present invention lies in the constitution of the magazine frame 20 and arm
30, so those are the parts that will be explained.
The magazine frame 20 is a box that stores staples 14 used
when stapling a sheaf of documents 12 or the like, and includes a staple guide.
The staple guide is the same as the staple guide of a conventional electric stapler.
The staple guides the staples 14 stored in the magazine frame 20 under pressure
toward the front end of the stapler, and comprises a spring which provides the pressing
force, a slide plate which is a moving body, a downward-facing U-shaped stapler
guide which pushes the staples forward, a shaft, and a cap which contacts the switch
at the back end of the shaft. The magazine frame 20 is made swingable through a
fulcrum 42 at its back end, whereby the front end of the frame can move up and down.
The arm 30 comprises a semicircular engagement circle that
engages gear protrusions (not shown), and a plate-shaped driver used for pushing
down staples at the front end. One of the staples lined up at the very front end
of the staples stored in the magazine frame 20 is separated from the line of staples
and pressure is applied to push it downward so that it penetrates the edge of documents
or the like, thereby completing the operation of stapling the documents. The engagement
circle is formed in an approximately semicircular shape, and is coupled to the circular
motion of the gear protrusions to thereby cause the arm 30 to move up and down.
Elastic body 50 is a flat plate provided with a convexity
arranged to abut the lower part of the magazine frame 20. When the magazine frame
20 is pushed down, the elastic body 50 has enough elastic force to return the magazine
frame 20 to its original position. A coil spring elastic body can be used instead
of the plate with a convexity of the elastic body 50 of this embodiment.
To have the weight of the magazine frame 20 push the staple
on to the document sheaf and effect staple penetration and fastening, the magazine
frame 20 and arm 30 swing up and down about fulcrums 42 and 44, with the arm 30
pushing down on a staple 14 stored in the magazine frame 20 and the magazine frame
20 swinging about fulcrum 42 to press against the document sheaf, while the elastic
body 50 provided on the lower part of the magazine frame returns the magazine frame
20 and arm 30 to the original position for stapling of the document sheaf 12.
The arm 30 pushing a staple 14 stored in the magazine frame
20 causes the magazine frame 20 to push downward. The magazine frame 20 coming into
abutment against the top of the document sheaf 12 in that state causes the arm 30
to push down a single staple 14 to penetrate and staple the document sheaf 12. When
the stapling operation is completed, the elastic body 50 provided to abut against
the lower part of the magazine frame 20 urges the magazine frame 20 back up to its
original position. As a result, the stapler is always ready for staples 14 to be
pressed to penetrate and staple document sheaves.
A deformation prevention member 60 is provided to prevent
the front end of the magazine frame 20 from becoming deformed over an extended period
of service usage time. The deformation prevention member 60 covers the tip of the
magazine frame 20, preventing staples from splaying out.
In accordance with the electric stapler described in the
foregoing, more stable stapling can be achieved than in the prior art, and the structure
is simpler. Moreover, stable operation is enabled by the provision of a deformation
prevention member on the magazine frame, which also makes it possible to achieve
stable closing performance.