Note: Descriptions are shown in the official language in which they were submitted.
2031~43
FASTENER DRIVER
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a fastener driver
driving fasteners, e.g., screws or nails into a
workpiece and more particularly to a simply-structured
fastener driver which automatically continuously feeds a
number of fasteners retained between a pair of straps
adhering to each other one by one to the front end of
the fastener driver to enable a continuous driving of
the fasteners.
Description of the Related Art
Hitherto, various fastener drivers in each of which
fasteners are continuously mechanically fed to a
fastener holder provided at the front end of the
fastener driver, i.e., without a need for manually
mounting the fasteners one by one to the front edge of a
rod-shaped drive bit of the fastener driver and each of
which can automatically continuously drive the fasteners
have been proposed.
Most of the fastener drivers have employed
compressed air for a power source for feeding a fastener
to the front end of a fastener driver and on the other
hand, a few of the fastener drivers have employed a
spring force for the power source.
Since the fastener driver employing compressed air
requires an air compressor, the air compressor is very
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203104~
inconveniently translated when the fastener driver mustbe used in a field job site or the like. On ~he other
hand, even when an ai~ source occasionally is present at
the field job site, an air hose must be extended from the
air source to the fastener driver, which is inconvenient
for handling the fastener driver.
On the other hand, since each of the fastener
drivers employing the spring force has a magazine case
containing fasteners and a feed mechanism of the
~agazine both movably mounted to the body of the
fastener driver and since they both have structures
experiencing an impact every time a fastener is fed to
the fastener holder provided at the front end of the
fastener driver, the fastener driver often fails.
The prior-art fastener drivers employing compressed
air or the spring force have the drawbacks described
above. In addition, they share a complicated structure
as a com~on drawback in a fastener driver leading to an
increasing in manufacturing cost and to an increasing in
the overall size of the fastener driver, which is
inconvenient to handle tne fastener driver.
SUMMARY OF THE INVEN~ r ON
An object of the present invention is to eliminate
the drawbacks in the prior-art fastener drivers and to
provide a compact, lightweight fastener driver with a
simple structure which securely feeds fasteners to the
front end of the fastener driver in an interlock with a
fastener driving operation of the fastener driver.
-- 2 -- =
20310~3
In accordance with a fastener driver of the present
invention, a tubular arrangement the front end of which
defines a fastener outlet is extendably and contractably
mounted to a fastener driver body, a drive bit is
mounted within the tubular arrangement, a fastener
feeder is mounted to the tubular arrangement, the
fastener feeder contains a pair of fastener guiding
plates opposite each other with a predetermined distance
therebetween so that the fastener guiding plates define
a fastener passage clearance sufficient to pass a
fastener assembly in which a strap retains rod-shaped
fasteners extending transversely of and arranged with a
predetermined pitch axially of the strap r one of the
fastener guiding plates define a fastener passage
opening for feeding a front one of the fasteners into
the tubular arrangement through a fastener feed hole
defined in the side wall of the tulular arrangement, a
fastener feed mechanism with a feed roller
intermittently engaging and advancing the strap is
provided, a fastener separation mechanism of which a
fastener separation element passes into and recedes out
of the fastener passage clearance through a hole defined
in the other fastener guiding plate, presses the front
fastener to separate the front fastener from the strap
when the fastener separation element extends out of the
fastener passage clearance, thereby to feed the
separated fastener into the tubular arrangement through
the fastener passage opening and fastener feed hole, and
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2031013
a first actuator and a second actuator both mounted to thefastener driver body actuate the respective fastener feed
mechanism and fastener separation mechanism.
In the operation of the fastener driver, an operator presses a
fastener driver on a workpiece so that the front end of the
tubular arrangement is in contact with a desired place of the
workpiece. Thereby, the operator first advances the fastener
driver body towards the workpiece so that the second actuator
concurrently advances to actuate the fastener separation
mechanism. That is, the fastener separation element presses the
front fastener and separates it from the strap to feed the
separated fastener into the tubular arrangement through the
fastener passage opening and fastener feed hole.
The operator further advances the fastener driver body so
that the front end of the drive bit further advances to fit a
groove defined in a head of the front fastener and then push the
front fastener out o~ the fastener outlet. Concurrently, the
first actuator advances to actuate the fastener feed mechanism so
that the feed roller engages and advances the strap. An
advancement of the fastener assembly caused by the feed roller
advances a fastener-free portion of the strap from which the last
fastener has been separated to a strap outlet defined in the other
fastener guiding plate.
Further scope of applicability of the present invention will
become apparent from the detailed description given hereinafter.
- 4 -
A
- - :
2U3104~
However, it should be understood that the detailed description and
specific examples, while indicating pre~erred embodiments of the
invention, are given by way of illustration only, since various
changes and modifications within the spirit and scope of the
invention will become apparent to those skilled in the art from
this detailed description.
The present invention will become more ~ully understood from
the detailed description given hereinbelow and the accompanying
drawings which are given by way of illustration only, and thus,
are not limitative o~ the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS . -.
FIG. 1 is a perspective view of a fastener driver
- 4A -
~ .
~ 20~1043
according to one embodiment of the present invention;
FIG.2 is a perspective view of a fragment of the
fastener driver of FIG.1 with first and second cases of
a fastener feeder opened;
; 11~ S ~ro ~S
FIG.3 illu¢trat~ front and rear perspective views
of a fastener assembly;
FIG.4 is a perspective view of the interior of the
opened fastener feeder of FIG.2 with the first and
second cases of the fastener feeder opened;
FIG.5 is a front sectional view of the interior of
the fastener feeder of FIG.2 with the first and second
cases opened;
FIG.6 is a cross section of the fastener feeder of
FIG.2 with the first and second cases closed;
FIG.7(A) is an enlarged view of a C-portion of
FIG.5;
FIG.7 (B) is a sectional view taken along the D-D
line in FIG.7(A);
FIG.8 is an exploded perspective view of a fastener
feed mechanism; and
FIG.9 is an illustration of nosepieces provided at
the front end of a tubular arrangement of the fastener
driver of FIG.1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the present invention
will be described in detail with reference to FIGS.1-9
hereinafter.
FIG.1 is a perspective view of a fastener driver
- 5 -
~ 2031043
(e.g., a screw driver~ in an operative position
according to one embodiment of the present invention.
FIG.2 is a perspective view of a fragment of the
fastener driver with first and second cases of a
fastener feeder opened. FIG.8 illustrates front and
rear perspective views of a fastener assembly. FIG.4 is
a perspective view of the interior of the fastener
feeder with the first and second cases of the fastener
feeder opened.
In each of FIGS.1-4, a fastener driver body is
indicated at 1, a rod-shaped drive bit extending
forwardly from the fastener driver body 1 is indicated
at 2, a case la of the fastener driver body 1 containing
an electrical motor as a motive source, a trigger switch
~ ct~t i ng
r~_ for an on off of the electrical motor is indicated at 3,
and a fastener drive attachment as main part of the
present invention is indicated at 4.
The fastener drive attachment 4 comprises a
telescopic tubular arrangement 5 which is extendable by
a coiled compression spring 13 (see FIG.5), a fastener
feeder 7 mounted to the front end of the telescopic
$ ~
tubular arrangement 5, the f~stcncrc feeder 7 delivering
fasteners ~i.e., screws) 10 connected in sequence by a
strap 6 into the telescopic tubular arrangement 5 and
sending a fastener-free portion of the strap 6 from
which fasteners 10 have been separated, and a first
actuator 8 and a second actuator ~ both for actuating
the fastener feeder 7. The fastener feeder 7 has a
- 6 -
20310~3
.
magazine 11 removably mounted thereto containing a
fastener assembly in which the strap 6 retains the
fasteners 10.
In detail, the telescopic tubular arrangement 5
comprises a first tube 5A, a second tube 5B, a third
tube 5C, a fourth tube 5D and a fifth tube 5E arranged
in this order from the rear to front of the fastener
driver, as shown in FIG.1. The first tube 5A is
removably fixed by means of a machine screw 12 to the
case la of the fastener driver body 1. The telescopic
tubular arrangement 5 contains the drive bit 2 and the
coiled compression spring 13 (see FIG.5) exerting a
force to the telescopic tubular arrangement 5 so as to
extend the respective second to fifth tubes 5B to 5E.
The fifth tube 5E constituting the front end of the
telescopic tubular arrangement 5 defines a fastener
outlet 14.
A pair of nosepieces 16 are provided in the
fastener outlet 14 and pivotably mounted by means of a
pair of pins 17 to a pair of notch defining portions of
the wall of the fifth tube 5E opposite each other. An
annular coiled spring 20 fits the outer cylindrical
surfaces of the nosepieces 16 and fifth tube 5E. When a
front fastener lOB is driven, the front fastener lOB
forcibly opens the nosepieces 16 against the force of
the annular coiled spring 20 and is pushed out of the
fastener outlet 14. In this state, once~operator
manually pushes the trigger switch 3, the electrical
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20310~3
motor moves to rotate the drive bit 2. The rotatingdrive bit 2 rotates the front fastener 10 fitting the
front edge of the drive bit 2 to drive the fastener 10
into the workpiece.
As shown in FIG.9, a pair of stop pins 17A are each
provided inside a nosepiece 16 between opposite wall
surfaces defining a notch 15 in the fifth tube 5E. Each
of the stop pins 17A stops an excessive inwardly-pivotal
movement of~corresponding one of the right-hand and
left-hand nosepieces 16 by means of being in contact
with an inner surface of the corresponding one of the
nosepieces 16. Thus, the stop pins 17A prevent the
nosepieces 16 from being out of alignment with the fifth
tube 5E so as to ensure a normal drive of a fastener 10
into the workpiece.
In order to smoothly extend and contract the second
to fifth tubes 5B to 5E, the front end of a guide bar 23
is fixed by means of a mount 22 to the top portion of
the cylindrical wall of the fifth tube 5E, a guiding
support 25 with a guiding hole 24 is mounted on the top
portion of the cylindrical wall of the first tube 5A and
the guide bar 23 is slidably mounted within the guiding
hole 24.
Thus, as the telescopic tubular arrangement 5 is
extended or contracted, the guide bar 23 moves forwards
or backwards within the guiding hole 24 and constitutes
a reinforcement for the telescopic tubular arrangement
5, so that the second to fifth tubes 5B to 5E are
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2031043
.
smoothly extended or contracted. Since the telescopictubular arrangement 5 is divided into a plurality of
stages, i.e., the first to fifth tubes 5A to 5E, the
length of the telescopic tubular arrangement 5 in a
contracted position secures a larger amount of a
projection of the front edge of the drive bit 2 from the
fastener outlet 14. Alternatively, a single
bellows-shape~ tube may be employed instead of the
telescopic tubular arrangement 5. The bellows-shaped
tube is mounted to the fastener driver body 1 so as to
e~do lD le
~be c~ctcdabl~ and contractable by a spring. When the
bellows-shaped tube is in a contracted position, the
front edge of the drive bit 2 is projected from the
fastener outlet in the front end of the bellows-shaped
tube so as to drive the front fastener lOB forwards out
of the fastener outlet.
The fastener feeder 7 will be described with
reference to FIG.1 to 8 hereinafter.
As shown in FIGS.1, 2, 4, 5, 6 and 8, the fastener
feeder 7 comprises a first case 27 and a second case 28
associated with each other by means of a pair of pins 30
and openable and closable about the pins 30. As shown
in FIG.6, the first case 27 has a first guiding plate 31
and the second case 28 has a second guiding plate 32 so
that a combination of the guiding plates 31 and 32
guides advancements of the ~asteners 10 ~rom the
magazine 11 to a fastener passage opening 46 defined in
$irst ~3 1
the ~coond guiding plate ~. When the fastener feeder 7
_ g _
20310q3
.
is mounted to the fifth tube 5E and the first and second
cases 27 and 28 are closed, the first and second guiding
plates 31 and 32 define therebetween a fastener passage
clearance 33 allowing the fastener assembly to pass
through.
A relationship between the first case 27 and fifth
tube 5E will be described with reference to FIGS.4 and 5
hereinafter. ~pposite portions of the cylindrical wall
of the fifth tube 5E difine a pair of cut faces 35
except the front end 34 of the fifth tube 5E (however,
FIG.4 can show only one cut face 35). The one cut face
35 defines a fastener feed hole 37 through which the
front fastener lOB can pass from the outside of the
fifth tube 5E into the interior 38 of the fifth tube 5E.
The first guiding plate 31 defines a guiding groove 29
extending along the axis of the first guiding plate 31.
An enlarged head of the fastener 10 slidably engages the
lower edge of the guiding groove 29 and advances along
the guiding groove 29.
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.
The first case 27 comprises the first guiding plate
31, a side plate 39 extending in parallel to the first
guiding plate 31, a bottom plate 40 extending between
the first guiding plate 31 and side plate 39, a front
plate 41 and a rear plate 42 both having a predetermined
height, and upper arc-shaped edges 43 of the front and
rear plates 41 and 42 so as to define a spacing 45. As
shown in FIG.5, the first guiding plate 31 defines a
fastener passage opening 46 in alignment with the
fastener feed hole 37 defined in the fifth tube 5E when
the fastener feeder 7 is mounted to the fifth tube 5E.
As best shown in FIG.5r the first guiding plate 31
of the first case 27 defines a circular hole 18 through
which a positioning pin 1'~ movably extends towards the
second guiding plate 32. A coiled compression spring 21
seated in a bracket mounted on the first guiding plate
31 is in contact with the rear end of the positioning
pin 19 and urges the positioning pin 19 towards the
second guiding plate 32.
As shown in FIG.6, the positioning pin 19 has an
oblique front edge surface and engages any of feed pitch
holes 26 defined along the axis of the strap 6, so as to
facilitate the fastener assembly to be loaded on a
fastener feed mechanism 50 described hereinafter. A
positioning mechanism related with the positioning pin
19 may be eliminated.
The fastener feed mechanism 50 and a fastener
separation mechanism 80 both provided in the second case
- 11 -
0 ~3.
28 will be described with reference to FIGS.2 to 5
hereinafter.
As best shown in FIGS.4 and 6, the second case 28
comprises a box-type case body 86 with one open side 87,
and the second guiding plate 32 mounted within the open
side 87. The case body 86 has a side plate 81, a front
plate 82, a rear plate 83, a top plate 84 and a bottom
plate 85.
The fastener feed mechanism 50 comprises a
rotatable shaft 44 the opposite ends of which are
supported on the front and rear plates 82 and 83 of the
second case 82. The rotatable shaft 44 has a feed
roller 49 fixed thereto and having three projections 48
equiangularly arranged circumferentially of the feed
roller 49. The projections 48 are inserted into the
feed pitch holes 26 in the straps 6 when the fastener
assembly is loaded on the fastener feeder 7 and when the
.~ seconl
first and CCQ~ cases 27 and 28 are closed.
As shown in FIGS.7(A) and 7~B), the cylindrical
surface of the rotatable shaft 44 defines a pair of
spiral grooves 51. An annular ratchet wheel 52 is
axially slidably mounted on the rotatable shaft 44. The
outer circumference of the ratchet wheel 52 has three
teeth 52A equiangularly arranged circumferentially of
the ratchet wheel 52. The inner circumference of the
ratchet wheel 52 has two opposite projections 53
engaging the spiral grooves 51.
The ratchet wheel 52 is seated in an actuation
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2031043
.
block 54 moving the ratchet wheel 52 along the rotatable
shaft 44. As shown in FIG.7~A), the actuation block 54
has a side view in the form of yoke, i.e., a
rectangular-U shape and a front prong 55A and a rear
prong 55B between which the ratchet wheel 52 is seated.
As shown in FIG.7(B), a pawl 56 is pivotably mounted by
means of a pivot 57 on the inside of the rear prong 55B.
The pawl 56 is engageable with each of the teeth 52A so
as to block a reversed rotation of the ratchet wheel 52
and thereby secure only a normal rotation the ratchet
wheel 52. As shown in FIG.4, the actuation block 54 is
fixed to the front end of an actuation rod 58. The
actuation rod 58 is supported by means of a support
block 70 fixed to the inner surface of the side plate 81
of the second case 28, on the side plate 81 and extends
movably through the rear plate 83 of the second case 28
so as to extend towards the fastener driver body 1. As
shown in FIG.5, coiled compression springs 59 and 60
seated around the actuation rod 58 between the support
block 70 and a retainer fixed to the actuation rod 58
serves to damp the axial movement of the actuation rod
58 at the front and rear limits of the axial movement of
the actuation rod 58. As shown in FIG.6, a leaf spring
61 has a rear end fixed to the inner surface of the side
plate 81 of the second case 28 and a front end having a
recess 61A. The recess 61A removably engages each of
the projections 48 of the rotating feed roller 49
a.cc~r ~e,
A intermittently so as to secure an aourrltc stop position
- 13 -
2031013
.
of the feed roller 49. Leaf springs 64A and 64B
opposite each other through a strap outlet 63 defined in
the side plate 81 are fixed to the inner surface of the
side plate 81 of the second case 28 and extend towards
the first case 27. The leaf springs 64A and 64B guide a
sending of a fastener-free portion of the strap 6 from
which the fasteners 10 have been separated. A return
compression spring 62 is seated around the rotatable
shaft 44 between the front plate 82 and actuation block
54 and returns rearwards the actuation block 54 which
has moved to the front end of the rotatable shaft 44,
when the telescopic tubular arrangement 5 is in an
extended position. The side plate 81 of the second case
28 defines the strap outlet 63 through which the
fastener-free portion of the strap 6 is discharged. A
retaining leaf spring 65 is fixed to the inner surface
of the first guiding plate 31 around the positioning pin
19. The retaining leaf spring 65 lightly presses the
fastener-free portion of the strap 6 on the cylindrical
surface of the feed roller 49.
A manner of loading the fastener assembly on the
fastener feed mechanism 50 will be described
hereinafter. As shown in FIG.2, the rear portion of the
strap 6 retaining the fasteners 10 is brought into
contact with the inner surface of the first guiding
plate 31 so that the positioning pin 19 extending from
the first guiding plate 31 towards the second case 28
passes through a feed pitch hole 26 in the strap 6 to
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2U310~
provisionally position the fastener assembly loaded on
the first guiding plate 31. In this state, the front
fastener lOB at the front position of a fastener
sequence is positioned in the fastener passage opening.
In this state, when the first and second cases 2
and 28 are closed together, the front edge of each
projection 48 of the feed roller 49 is brought into
contact with the front edge of the positioning pin lg
mounted to the first case 27 to push the positioning pin
19 against the force of the coiled compression spring
21. Thus, the positioning pin 19 is removed out of the
feed pitch hole 26 in the strap 6 of the fastener
assembly and the projection 48 of the feed roller 49 is
i~mediately inserted into the same feed pitch hole 26.
In the insertion of the projection 48 into the feed
pitch hole 26, the contacting, oblique edges of the
positioning pin 19 and projection 48 prevent both the
positioning pin 19 and projection 48 from disengaging
from the feed pitch hole 26.
The rear edge 58A of the actuation rod 58 is spaced
a predetermined distance from the first actuator 8.
Thus, when in fastener drive, the front end of the fifth
tube 5E is brought into contact with the workpiece and
operator pushes the fastener driver body 1 towards the
workpiece so that the telescopic tubular arrangement 5
is contracted, the first actuator 8 advances the
predetermined distance to come into contact with the
rear edge 58A of the actuation rod 58 and thereby
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2031043
advance the actuation rod 58. The advancement of the
actuation rod 58 advances the ratchet wheel 52 by means
of the actuation block 54 fixed to the actuation rod 58.
The ratchet wheel 52, a reversed rotation of which is
blocked by the combination of the teeth 52A and pawl 56,
advances along the rotatable shaft 44 without rotating,
so that the camming engagement between the projections
53 of the ratchet wheel 52 and the spriral grooves 51 in
the rotatable shaft 44 rotates the rotatable shaft 44 by
a predetermined angles, i.e., 120 . The 120 rotation of
the rotatable shaft 44 rotates the feed roller 49 by 120
so that the projection 48 advances the strap 6 of the
fastener assembly by a distance corresponding to 120.
After completion of fastener drive, the fastener
driver body 1 is moved rearwards away from the workpiece
so that the force of the coiled compression spring 62
seated around the rotatable shaft 44 moves the actuation
block 54 and ratchet wheel 52 rearwards. Thus, the
camming engagement between the projections 53 of the
ratchet wheel 52 and the spriral grooves 51 in the
rotatable shaft 44 rotates the ratchet wheel 52
counterclockwise in FIG.7(B) as the ratchet wheel 52 is
moved rearwards, so that the rotatable shaft 44 cannot
be reversely rotated. Thus, only a one-directional
rotation of the feed roller 49 can be intermittently
performed in order to advance the strap 6 of the
fastener assembly.
The fastener assembly with the strap 6 will be
- 16
~ 20310~3
described with reference to FIG.3 hereinafter. The
strap 6 comprises a pair of paper strap halves 6A and 6B
~ h~
each mader e.g., of kraft paper. Each of~contacting
surfaces of the paper strap halves 6A and 6B has a
laminated layer made of a plastic fil~, e.g.,
polyethylene film ~not shown). The paper strap halves
6A and 6B sandwich the fasteners 10 each extending
transversly of the paper strap halves 6A and 6B and
generally arranged along the paper strap halves 6A and
6B with a fixed pitch. The enlarged head of each
fastener 10 is positioned above the upper edge of the
strap 6 and the pointed end of each fastener 10 is
positioned below the lower edge of the strap 6. A
portion of the strap 6 in front of each fastener 10 and
a portion of the strap 6 in rear of that fastener 10 are
heat sealed thereby to define a tubular fastener
retainer 75 retaining that fastener 10.
The paper strap half 6A defines separation holes so
that each fastener 10 is readily separated from the
strap 6 when that fastener 10 is driven. In
p~t;c~
particular~, as shown in the right-hand side of FIG.3,
the paper strap half 6A defines perforations 76 arranged
transversely of the strap 6 each in front of and in rear
of each fastener retainer 75 and on each fastener
retainer 75. Alternatively, only the perforations 76 on
each fastener retainer 75 may be provided. The other
paper strap half 6B has no separation holes.
Thusr a fastener separation lever 77 as shown in
- 1 7
2031043
.
FIG.3 (the structure and operation of the separation
lever 77 will be later described in detail) has upper
and lower projections 78 respectively pressing a neck
and shank of the front fastener lOB from the side of the
other paper strap half 6B to tear a corresponding
fastener retainer 75 by means of the perforations 76 in
the one paper strap half 6A so that the front fastener
lOB is readily separated from the strap 6.
As described above, the center of the width Pf each
portion of the strap 6 between adjacent fastener
retainers 75 defines the feed pitch hole 26.
The fastener separation mechanism 80 provided in
the second case 28 will be described with reference to
FIGS.2, 3, 4 and 6 hereinafter. As best shown in FIG.4,
the lower end of the fastener separation lever 77 is
pivotably mounted on and within the second case 28 by
means of a pivot 88 (a machine screw is employed as
shown in FIG.4) and urged towards the side plate 81 of
the second case 28 by means of a coiled tension spring
89.
As shown in FIG.4, a first arm is indicated at 91
and a second arm is indicated at 92. The first and
second arms 91 and 92 extend oppositely sidewards from a
hollow cylinder 93 rotatably mounted on a shaft 90 fixed
to the rear plate 83 of the second case 28. The front
end of the first arm 91 engages a rear portion of the
fastener separation lever 77. One end of the shaft 90
is fixed to the rear plate 83 of the second case 28 and
- 1 8 -
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.
the other end of the shaft 90 is supported on a bracket95 fixed to the inner surface of the side plate 81.
A front end of the second arm 92 has a pin 99
extending forwards. The pin 99 passes through a
U-shaped notch 97 of a yoke portion of an oscillator 96
A made with~ L-shaped metal plate so as to engage the two
prongs of the yoke portion. The oscillator 96 is
pivotably mounted on a pivot pin 98 fixed to the inner
surface of the bottom plate 85 of the second case 28.
As shown in FIG.4, a pull bar is indicated at 100.
The pull bar 100 slidably passes through a hole 101
defined in the rear plate 83 of the second case 28. An
outer end of the pull bar 100 has a disc-shaped flange
102. An inner portion of the pull bar 100 is bent at a
right angle. An inner end of the pull bar 100 is
inserted through a hole 103 defined in the oscillator
96.
Thus, when the second guiding plate 32 is mounted
within a side opening of the case body 86 of the second
case 28 as shown in FIG.6 and then the pull bar 100 is
moved rightwards and leftwards as shown by arrows in
FIG.4, the second arm 92 rotates the fastener separation
lever 77 about the pivot 88 through a linkage of the
pull bar 100, oscillator 96, pin 99, first arm 91 and
hollow cylinder 93 against and by the force of the
coiled tension spring 89.
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When the fastener separation lever 77 is moved
against the force of the coiled tension spring 89, the
upper and lower projections 78 of the fastener
separation lever 77 extend out of a rectangular opening
104 defined in the second guiding plate 32 towards the
first guiding plate 31 of the first case 27 and press
the neck and shank of the front fastener lOB retained in
the strap 6 to separate the front fastener lOB fro~ the
strap 6.
As shown in FIG.4, the second guiding plate 32
defines a fastener head guiding groove 109 communicating
with the rectangular opening 104 and opposite the
guiding groove 29 in the first guiding plate 31 when the
first and second cases 27 and 28 are closed.
When the first and second cases 27 and 28 are
closed, the fastener separation lever 77 is opposite
fastener passage opening 46 defined in the first guiding
plate 81 so that the projections 78 of the fastener
separation lever 77 can press the front fastener lOB
positioned within the fastener passage opening 46 and
retained in the strap 6. Thus, the projections 78
extend out of the rectangular opening 104 in the second
guiding plate 32 to tear the fastener retainer 75 at the
perforations defined on the fastener retainer 75 and
thereby separate the front fastener lOB from the strap
6. Then, the fastener separation lever 77 delivers the
front fastener lOB into the fifth tube 5E through the
fastener passage opening 46 in the first guiding plate
- 20
20~1043
31 and the fastener feed hole 37 in the fifth tube 5E.
The drive bit 2 pushes the front fastener lOB which
has been fed into the fifth tube 5E so that the front
edge of the drive bit 2 fits a plus-shaped groove in the
head of the front fastener lOB. The front fastener lOB
forcibly opens the nosepieces 16 against the force of
the annular spring 20 and then is rotated to be driven
into the workpiece.
An actuation mechanism for the fastener separation
mechanism 80 will be described with reference to FIG.8
hereinafter. As shown in FIG.8, a slide plate the front
A end of which is bent at~right angle to the body of the
slide plate and terminates at a yoke with a U-shaped
notch 106 is indicated at 105. The yoke with the
U-shaped notch 106 engages the disc-shaped flange 102
provided on the outer end of the pull bar 100. A
retaining plate 107 retains the slide plate 105 and
moves the slide plate 105 forwards and rearwards. A
rectangular tubular guide for a second rod-shaped
actuator 9 slidably mounted therewithin is indicated at
108. The top surface of the front end of the tubular
guide 108 is welded to the underside of the bottom plate
40 of the first case 27. The retaining plate 107 is
spot-welded at 110 to the top surface of the tubular
guide 108.
A lever pivotably mounted by means of a pivot 112
to the underside of the retaining plate 107 is indicated
at 111. The lever 111 has a slot 113 extending axially
- 21
20310~3
thereof. A pin 114 passes freely through the slot 113
and has the top end fixed to the underside of the slide
plate 105. A coiled tension spring 115 one end of which
is mounted to the pin 114 urges the lever 111 to rotate
counterclockwise about the pivot 112. Thus, as the
A lever lllis rotated clockwise and counterclockwise in
FIG.8, the slide plate 105 is moved rearwards and
forwards.
A relationship between the second rod-shaped
actuator 9 and lever 111 will be described hereinafter.
The second rod-shaped actuator 9 has a portion with a
predetermined length extending between the front edge
and an intermediate portion and having a rectangular
V~shaped cross-section. The rear end of the second
rod-shaped actuator 9 is fixed by means of a machine
screw 116 to the underside of the outer cylindrical
surface of the first tube 5A as shown in FIGS.1 and 2.
When the second rod-shaped actuator 9 is within the
tubular guide 108, an upright end 117 of the lever 111
passes through a slot 113 defined in a side wall of the
tubular guide 108 and extending axially of the tubular
guide 108 into the tubular guide 108 and is~contact with
vertical actuating surfaces 118 or the bottom surface of
a groove 120 extending axially of the second rod-shaped
actuator 9 when the second rod-shaped actuator 9 is
moved forwards or rearwards axially of the tubular guide
108.
The relationship between the second rod-shaped
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actuator 9 and lever 111 will be described in more
detail hereinafter. A coiled compression spring 121 is
seated around a pivot 112 and urges the lever 111
upwards in FIG.8. As shown in an encircled enlarged
view of FIG.8, when the upright end 117 of the lever 111
passes through the slot 113 into the tubular guide 108
and when the front edge 123 of the second actuator 9
moves leftwards in the encircled enlarged view of FIG.8
and disengages from the upright end 117 of the lever
111, the upright end 117 of the lever 111 is immediately
lifted up and brought into the inner surface of the top
wall 122 of the tubular guide 108 by the force of the
coiled compression spring 121 so that the position of
the upright end 117 of the lever 111 is as high as that
of the vertical actuating surfaces 118. In this state,
the lever 111 is rotated counterclockwise in FIG.8 by
the force of the coiled tension spring 115 until the
upright end 117 of the lever 111 is brought into contact
with the rear edge of the slot 113 defined in the
tubular guide 108.
In this state, when the second actuator 9 is
advanced, the upright end 117 of the lever 111 rides on
the front stage of the vertical actuating surfaces 118
so that the lever 111 is rotated clockwise in FIG.8
against the force of the coiled tension spring 115 until
the upright end 117 of the lever 111 is brought into
contact with the front edge of the slot 113 defined in
the tubular guide 108. Thereby, the slide plate 105 is
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2031043
moved reawards ~i.e., leftwards in FIG.8) to pull the
pull bar 100 (i.e., move leftwards in FIG.8~.
As described above, pulling the pull bar 100
extends the projections 78 of the fastener separation
lever 77 out of the rectangular opening 104 defined in
the second guiding plate 32 towards the first guiding
plate 31 to separate the front fastener lOB from the
strap 6. As shown in FIG.8, since the vertical
actuating surfaces 118 have a plurality of steps 125
thcrcintcrm~diatQ, they stepwise control the rotation of
lever 111 so that the projections 78 of the fastener
separation lever 77 are moved stepwise with
accelerations to easily separate the front fastener from
the strap ~.
The rearmost edge of the rearmost stage of the
vertical actuating surfaces 118 has an oblique underside
surface 126 projecting transversely of the second
actuator 9 and extending to the bottom of the groove
120. Thus, when the second actuator 9 advances a
predetermined distance until the upright end 117 of the
lever 111 is brought into the oblique underside surface
126, the upright end 117 of the lever 111 immediately is
Sl;~
slidcd by the force of the coiled tension spring 115
along the oblique underside surface 126 to the bottom of
the groove 120 while the lever 111 is descended along
the pivot 112 against the force of the coiled
compression spring 121.
As the lever 111 is concurrently rotated
- 2 4
~0~104~
.
counterclockwise about the pivot 112 in FIG.8, the slide
plate 105 is advanced to return the pull bar 100 to its
rti~l position. Thereby, the fastener separation lever
77 exits out of the rectangular opening 104 defined in
the second guiding plate 32 to complete the separation
of the front fastener lOB from the strap 6.
When the upright end 117 of the lever 111 has
fallen to the bottom of the groove 120, the lever 111
cannot receive an effect of a backward movement of the
second actuator 9. When the second actuator 9 is moved
to its backwardmost position, the front edge 123 of the
second actuator 9 releases the upright end 117 of the
lever 111 which in turn is repeatedly lifted up to the
position of the vertical actuating surfaces 118 of the
second actuator 9 to provide for a next stroke of
fastener drive.
The fastener driver separates from the strap 6 the
front fastener lOB positioned within the fastener
passage opening 46 defined in the first guiding plate 31
and feeds the front fastener lOB into the fifth tube 5E
~ n
in one stroke of fastener drive in which~operator
presses the front edge of the fifth tube 5E on the
workpiece to contract the telescopic tubular arrangement
5 and drives the front fastener lOB into the workpiece.
In the stroke of fastener drive, the second
actuator 9 actuates the pull bar 100 for the
predetermined period of time corresponding to the
initial distance between the first actuator 8 and the
- 2 5
~ 203104~
rear end 58A of the actuation rod 58 before the first
actuator 8 is brought into contact with the rear end 58A
A of the actuation rod 58, so that~operator initially
presses the fifth tube 5~ on the workpiece, then the
second actuator 9 actuates the fastener separation
mechanism 80 to separate the front fastener lOB from the
strap 6 and then feed the separated front fastener lOB
into the fifth tube 5E. Then, the first actuator 8
actuates the fastener feed mechanism 50 to advance the
fastener assembly by means of the engage~ent of the
projection 48 of the feed roller 49 with the feed pitch
hole 26 defined in the strap 6 and thereby feed a next
fastener lOA into the fastener passage opening 46
defined in the first guiding plate 31.
As shown in FIG.6, the fastener feed operation of
the feed roller 49 advances the fastener-free portion of
the strap 6 through the spacing between the pair of leaf
springs 64A and 64B both extending along the outer
cylindrical surface of the feed roller 49 and through
the strap outlet 63 defined in the side plate ~ of the
second case 28 out of the second case 28.
As shown in FIG.4, a lock lever pivotably mounted
on the inner surface of the rear plate 83 of the second
case 28 by means of a pivot 128 is indicated at 127.
The lock lever 127 extends between the outside and
inside of the second case 28 and has an inner end with a
bent pawl 130.
When the first and second cases 27 and 28 are
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~ 2031043
closed, the pawl 130 of the lock lever 127 engages an
edge of a lock hole 131 defined near a corner of the
first guiding plate 31 of the first case 27 to lock the
first and second cases 27 and 28 in their closed
positions. A coiled tension spring 132 urges the lock
lever 127 so that the pawl 130 engages the edge of the
er~or
lock hole 131. O~crator can grip the outer end of the
lock lever 127 and rotate the lock lever 127 against the
force of the coiled tension spring 132 in order to
disengage the pawl 130 from the lock hole 131 and open
the first and second cases 27 and 28.
A magazine 11 will be described with reference to
FIGS.1, 5 and 6 hereinafter. The magazine 11 comprises
a fixed body 136 and movable element 137 associated with
the fixed body 136 by means of pivot 138. The fixed
body 136 comprises a front disc 140 and semicylindrical
wall 141 integrated with each other. The
semicylindrical wall 141 has a mount bracket 142 by
means of which the fixed body 136 is attached by means
of a srew or the like to the tubular guide 108. On the
other hand, the magazine movable element 137 comprises a
truncated conical cap 145 opposite the front disc 140
when the magazine 11 is in a closed position, and a
semicylindrical wall 143 mating with the semicylindrical
wall 141 of the fixed body 136. The magazine movable
element 137 contains a pushing plate 146 in contact with
and slightly presses the enlarged heads of the fasteners
10 of the spriraled fastener assembly, the pushing plate
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~ 2031043
146 being movably mounted within the magazine movable
element 137.
In more detail, a tubular guide 147 passes through
a hole defined in the center of the cap 145 and is fixed
to the cap 145. A shaft 148 extending from the pushing
plate 146 passes into and is movable axially of the
tubular guide 147. A coiled compression spring 150 is
seated around the shaft 148 between the pushing plate
146 and a retainer provided at a free end of the tubular
guide 148 so as to urge the pushing plate 146 to
slightly push the heads of the fasteners 10. The outer
surface of the truncated portion of the cap 145 has a
nob 151 to handle the magazine movable element 137.
In an operation of charging the fastener assembly
~ he,
in the magazine ll,~operator opens the magazine movable
element 137 about the pivot 138, then charges the
~prira~cd-fastener assembly having the strap 6 and
extends a front portion of the fastener assembly out of
an opening 152 defined in the magazine 11, and then
closes the magazine movable element 137 as shown in
FIG.6. An illustration of a latch holding the magazine
movable element 137 in a closed position is eliminated.
As described above,~operator opens the second case
28 of the fastener feeder 7 after charging the fastener
assembly in the magazine 11 and mounts a front portion
of the fastener assembly which retains some fasteners 10
to the first guiding plate 31 so that the positioner 19
passes through a feed pitch hole 26 defined in the strap
- 2 8 -
203iO13
6. Then, the operator closes the second case 28 to the first case
27. A~ter the completion of a fastener assembly setting, the
operator can ~reely drive the fasteners 10 in accordance with the
stroke o~ fastener drive.
The invention being thus described, it will be obvious that
the same may be varied in many ways. Such variations are not to
be regarded as a departure from the spirit and scope of the
invention, and all such modifications as would be obvious to one
skilled in the art are intended to be included within the scope o~
the following claims.
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