Information
-
Patent Grant
-
6467243
-
Patent Number
6,467,243
-
Date Filed
Friday, July 27, 200123 years ago
-
Date Issued
Tuesday, October 22, 200222 years ago
-
Inventors
-
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 100 4
- 100 26
- 100 29
- 053 494
- 053 67
- 053 74
- 053 589
-
International Classifications
- B65B1304
- B65B5710
- B65B1324
-
Abstract
A strapping machine includes a machine body with a package-strapping space. A strap is fed to the package-strapping space. A spring-loaded swing arm is pivoted to the machine body, and is associated with a rotating shaft via a cam unit such that rotation of the shaft results in turning of the swing arm relative to the machine body. An electrically operated clamp unit is mounted movably on the swing arm, and is movable relative to a strap passage in the swing arm. A delay circuit is electrically coupled to a detecting device and the clamp unit. When the detecting device detects a first position of the swing arm, the delay circuit will actuate the clamp unit to move from a releasing position to a clamping position after a preset delay time. When the detecting device detects a second position of the swing arm, the clamp unit is immediately actuated to move from the clamping position to the releasing position.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a strapping machine, more particularly to a strapping machine with a strap tightening adjustment unit of a simple structure.
2. Description of the Related Art
Referring to
FIGS. 1
to
3
, a conventional strapping machine is shown to include a machine body
1
, a strap supply reel
14
, a strap feed unit
13
, a rotating shaft unit
122
, and a strap tightening adjustment unit
4
.
As illustrated, the machine body
1
defines an accommodating space
11
and a package-strapping space
12
above the accommodating space
11
. The strap supply reel
14
is mounted on an exterior of the machine body
1
. A bundle of strap
2
is mounted on the strap supply reel
14
, and has a leading end fed into the package-strapping space
12
by the strap feed unit
13
in such a manner that a package strapping operation can be done in the package-strapping space
12
. The rotating shaft unit
122
is journalled in the accommodating space
11
of the machine body
1
, and is formed with a cam unit
123
.
The strap tightening adjustment unit
4
includes a spring-loaded swing arm
41
, a clamp unit
5
, and a strap tension adjuster
6
. A mounting shaft
113
extends through a mounting bracket
111
of the machine body
1
and the swing arm
41
to mount the latter pivotally within the accommodating space
11
. The swing arm
41
is further associated with the rotating shaft unit
122
via the cam unit
123
in such a manner that rotation of the shaft unit
122
results in turning of the swing arm
41
relative to the machine body
1
along a travelling path
131
between an upper position adjacent to the package-strapping space
12
and a lower position distal from the package-strapping space
12
. The swing arm
41
defines a strap passage
414
to permit extension of the strap
2
therethrough, and a rod-path
415
in spatial communication with the strap passage
414
. The clamp unit
5
includes a clamp piece
54
, a push rod
51
, and a torsional spring
52
. The clamp piece
54
is mounted pivotally on the swing arm
41
via a pivot
53
. The push rod
51
is disposed movably in the rod-path
415
of the swing arm
41
, and is operably associated with the clamp piece
54
. The torsional spring
52
is sleeved around the pivot
53
so as to urge the push rod
51
in the rod-path
415
toward a first direction away from the strap passage
414
so as to relieve clamping of the clamp piece
54
relative to the strap
2
. The strap tension adjuster
6
includes an adjuster shaft
61
which is mounted rotatably in the mounting bracket
111
of the accommodating space
11
and which extends parallel to and adjacent to the mounting shaft
113
, a spring-loaded rod pusher
64
which is sleeved on the mounting shaft
113
and which urges the push rod
51
to move in a second direction opposite to the first direction so as to result in clamping of the clamp piece
54
relative to the strap
2
in the strap passage
414
, and a tension adjusting wheel
62
which is fixed eccentrically on the adjuster shaft
61
and which is in sliding contact with the rod pusher
64
via a coupler unit
63
.
When the swing arm
41
is pivoted to a position between the upper and lower positions by virtue of rotation of the shaft unit
122
, the rod pusher
64
and the coupler unit
63
concurrently rotate with the swing arm
41
. Collision of a protrusion
631
on the coupler unit
63
with the adjusting wheel
62
results in stoppage of the rotation of the coupler unit
63
on the shaft
113
, which in turn, results in movement of the clamp piece
54
in the second direction toward the strap passage
414
of the swing arm
41
by virtue of urging action of the rod pusher
64
against the push rod
51
(see FIG.
4
), thereby clamping and tightening the strap
2
around the package that is disposed in the package-strapping space
12
of the machine body
1
.
Note that the strap tightening adjustment unit
4
of the conventional strap machine includes a relatively large number of components, and is therefore consequently complicated in structure and incurs a long assembly time during the manufacture of the conventional strapping machine.
SUMMARY OF THE INVENTION
Therefore, the object of this invention is to provide a strapping machine with a strap tightening adjustment unit of a simple structure so as to overcome the aforementioned disadvantages that are associated with the conventional strapping machine.
Accordingly, a strapping machine of the present invention includes a machine body, a strap supply reel, a strap feed unit, a rotating shaft unit, and a strap tightening adjustment unit. The machine body defines an accommodating space and a package-strapping space above the accommodating space. The strap supply reel is mounted on the machine body, and is adapted to hold a bundle of strap thereon. The strap feed unit is capable of feeding the strap from the strap supply reel to the package-strapping space of the machine body. The rotating shaft unit is journalled in the accommodating space of the machine body, and is formed with a cam unit. The strap tightening adjustment unit includes a spring-loaded swing arm, an electrically operated clamp unit, a detecting device, and a delay circuit. The swing arm is pivoted to the machine body within the accommodating space, and is associated with the rotating shaft unit via the cam unit in such a manner that rotation of the shaft unit results in turning of the swing arm relative to the machine body between an upper position adjacent to the package-strapping space and a lower position distal from the package-strapping space. The swing arm defines a strap passage which is adapted to permit extension of the strap therethrough. The clamp unit is mounted movably on the swing arm, and is movable relative to the strap passage between a clamping position, in which the strap is clamped by the clamp unit, and a releasing position, in which the strap is released from the clamp unit. The delay circuit is electrically coupled to the detecting device and the clamp unit. When the detecting device detects a first position of the swing arm between the upper and lower positions, the delay circuit will actuate the clamp unit to move from the releasing position to the clamping position after a preset delay time. When the detecting device detects a second position of the swing arm between the first and lower positions, the clamp unit is immediately actuated to move from the clamping position to the releasing position.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features and advantages of this invention will become more apparent in the following detailed description of the preferred embodiment of this invention, with reference to the accompanying drawings, in which:
FIG. 1
is a schematic view of a conventional strapping machine for strapping a package;
FIG. 2
is a fragmentary exploded perspective view to illustrate a strap tightening adjustment unit of the conventional strapping machine;
FIG. 3
is a fragmentary assembled perspective view of the conventional strapping machine, illustrating how the strap tightening adjustment unit is mounted on a machine body;
FIG. 4
is a fragmentary schematic view of the conventional strapping machine, illustrating how the strap tightening adjustment unit is operated;
FIG. 5
is a schematic view of a preferred embodiment of a strapping machine according to the present invention;
FIG. 6
is a fragmentary schematic view of the preferred embodiment, illustrating how a swing arm of a strap tightening adjustment unit is mounted on a machine body;
FIG. 7
is a fragmentary schematic view of the preferred embodiment, illustrating how the swing arm of the strap tightening adjustment unit is actuated so as to move the same to a first position;
FIG. 8
is a schematic view of the preferred embodiment, viewed from line VIII—VIII in
FIG. 7
, illustrating how a first micro switch is actuated by a first actuator mounted fixedly on a rotating shaft;
FIG. 9
shows a clamp unit of the preferred embodiment at a clamping position;
FIG. 10
is a fragmentary schematic view of the preferred embodiment, illustrating how the swing arm of the strap tightening adjustment unit is actuated in order to tighten a strap relative to the package;
FIG. 11
illustrates how a second micro switch is actuated by a second actuator in the preferred embodiment;
FIG. 12
is a fragmentary schematic view of the preferred embodiment, illustrating how the swing arm of the tightening adjustment unit is restored to its initial position; and
FIG. 13
illustrates how a third micro switch is actuated by a third actuator in the preferred embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to
FIGS. 5
,
6
, and
7
, the preferred embodiment of a strapping machine for strapping a package
90
according to the present invention is shown to include a machine body
7
, a strap supply reel
60
, a strap feed unit
73
, a rotating shaft unit
722
, and a strap tightening adjustment unit
9
.
As illustrated, the machine body
7
defines an accommodating space
70
and a package-strapping space
71
above the accommodating space
70
. The package
90
is disposed in the package-strapping space
71
of the machine body
7
for strapping.
The strap supply reel
60
is mounted on the machine body
7
, and holds a bundle of strap
8
thereon.
The strap feed unit
73
is disposed in the accommodating space
70
of the machine body
7
, and can feed the strap
8
from the strap supply reel
60
to the package-strapping space
71
in such a manner that after encircling around the package
90
, a distal end of the strap
8
is fixedly retained underneath on a support plate that supports the package
90
thereon.
The rotating shaft unit
722
is journalled between two mounting walls
712
(only one is shown in
FIGS. 6 and 7
) in the accommodating space
70
of the machine body
7
, and is formed with a cam unit
723
.
The strap tightening adjustment unit
9
includes a spring-loaded swing-arm
91
, an electrically operated clamp unit
95
, a detecting device
100
, and a delay circuit
104
. The swing arm
91
has a lower portion
911
pivoted to a pivot seat
711
within the accommodating space
70
of the machine body
7
, and is associated with the rotating shaft unit
722
via the cam unit
723
in such a manner that rotation of the shaft unit
722
results in turning of the swing arm
91
relative to the seat
711
between an upper position adjacent to the package-strapping space
71
, as best shown in
FIG. 5
, and a lower position (not shown) distal from the package-strapping space
71
. The swing arm
91
has an upper portion
912
that is formed with a strap passage
916
(see
FIG. 9
) to permit extension of the strap
8
therethrough when the strap
8
is fed by the strap feed unit
73
from the strap supply reel
60
to the package-strapping space
71
of the machine body
7
. The clamp unit
95
is mounted movably on the swing arm
91
, and is movable relative to the strap passage
916
between a clamping position, in which the strap
8
is clamped by the clamp unit
95
, and a releasing position, in which the strap
8
is released from the clamp unit
95
.
The delay circuit
104
is electrically coupled to the detecting device
100
and the clamp unit
95
in such a manner that when the detecting device
100
detects a first position of the swing arm
91
between the upper and lower positions, as best shown in
FIG. 7
, the delay circuit
104
will actuate the clamp unit
95
to move from the releasing position to the clamping position after a preset delay time. Under this condition, the strap
8
around the package
90
is tightened by virtue of rotation of the shaft unit
722
and concurrent movement of the upper portion
912
of the swing arm
91
from the upper position to the first position. When the detecting device
100
detects a second position of the swing arm
91
between the first and lower positions (see FIGS.
10
and
11
), the clamp unit
95
is immediately actuated to move from the clamping position to the releasing position, which in turn releases the strap
8
from the clamp unit
95
.
The detecting device
100
includes first and second micro switches
101
,
102
which are disposed in the accommodating space
70
of the machine body
7
adjacent to the rotating shaft unit
722
and which are electrically coupled to the delay circuit
104
, and first and second actuators
724
,
725
which are fixed on the rotating shaft unit
722
and which are capable of contacting the first and second micro switches
101
,
102
respectively when the swing arm
91
is at the first and second positions, as best shown in
FIGS. 8 and 11
. A drive unit
72
is provided for rotating the rotating shaft unit
722
. The detecting device
100
further includes a third micro switch
103
which is disposed in the accommodating space
70
of the machine body
7
adjacent to the rotating shaft unit
722
and which is electrically coupled to the drive unit
72
, and a third actuator
726
which is fixed on the rotating shaft unit
722
and which is capable of contacting the third micro switch
103
when the swing arm
91
is at the lower position to control the drive unit
72
to stop rotation of the shaft unit
722
, as best shown in
FIGS. 12 and 13
. Under this condition, the swing arm
91
is moved back to its initial position of
FIG. 12
by virtue of tension force of a spring
914
which interconnects the mounting wall
712
and the swing arm
91
.
In this preferred embodiment, the delay circuit
104
includes a motor
97
operably connected to the clamp unit
95
via a turning plate
96
and a push rod
92
(see
FIG. 9
) in such a manner that the motor
97
rotates in a first direction so as to move the clamp unit
95
from the releasing position to the clamping position when the first actuator
724
contacts the first micro switch
101
. In the same manner, the motor
97
rotates in a second direction opposite to the first direction so as to move the clamp unit
95
from the clamping position to the releasing position when the second actuator
725
contacts the second micro switch
102
.
Referring to
FIG. 9
, the clamp unit
95
preferably includes a u-shaped clamp seat
913
which is fixed on the upper portion
912
of the swing arm
91
(see
FIG. 6
) and which defines the strap passage
916
and a push-rod path
917
that is disposed above the strap passage
916
and that receives the push rod
92
therein, a clamp piece
950
pivoted to the seat
913
via a pivot
93
, and an urging member
94
that is sleeved around the pivot
93
and that urges the clamp piece
950
via the push rod
92
so as to clamp the strap
8
in the strap passage
916
of the seat
913
when the motor
97
rotates in the first direction.
Claims
- 1. A strapping machine for strapping a package, comprising:a machine body defining an accommodating space and a package-strapping space above said accommodating space; a strap supply reel mounted on said machine body and adapted to hold a bundle of strap thereon; a strap feed unit capable of feeding the strap from said strap supply reel to said package-strapping space; a rotating shaft unit journalled in said accommodating space, and formed with a cam unit; a strap tightening adjustment unit including a spring-loaded swing arm pivoted to said machine body within said accommodating space and associated with said rotating shaft unit via said cam unit in such a manner that rotation of said shaft unit results in turning of said swing arm relative to said machine body between an upper position adjacent to said package-strapping space and a lower position distal from said package-strapping space, said swing arm defining a strap passage adapted to permit extension of the strap therethrough, an electrically operated clamp unit mounted movably on said swing arm and movable relative to said strap passage between a clamping position, in which the strap is clamped by said clamp unit, and a releasing position, in which the strap is released from said clamp unit, a detecting device, and a delay circuit electrically coupled to said detecting device and said clamp unit, wherein, when said detecting device detects a first position of said swing arm between said upper and lower positions, said delay circuit will actuate said clamp unit to move from said releasing position to said clamping position after a preset delay time, and wherein, when said detecting device detects a second position of said swing arm between said first and lower positions, said clamp unit is immediately actuated to move from said clamping position to said releasing position.
- 2. The strapping machine as defined in claim 1, wherein said detecting device includes first and second micro switches disposed in said accommodating space of said machine body adjacent to said rotating shaft unit and electrically coupled to said delay circuit, and first and second actuators which are fixed on said rotating shaft unit and which are capable of contacting said first and second micro switches respectively when said swing arm is at said first and second positions.
- 3. The strapping machine as defined in claim 2, further comprising a drive unit for rotating said rotating shaft unit, said detecting device further including a third micro switch disposed in said accommodating space of said machine body adjacent to said rotating shaft unit and electrically coupled to said drive unit, and a third actuator which is fixed on said rotating shaft unit and which is capable of contacting said third micro switch when said swing arm is at said lower position so as to control said drive unit to stop rotation of said rotating shaft unit.
- 4. The strapping machine as defined in claim 2, wherein said delay circuit includes a motor operably connected to said clamp unit, said motor rotating in a first direction so as to move said clamp unit from said releasing position to said clamping position when said first actuator contacts said first micro switch, said motor rotating in a second direction opposite to said first direction so as to move said clamp unit from said clamping position to said releasing position when said second actuator contacts said second micro switch.
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Number |
Name |
Date |
Kind |
RE27744 |
Billett et al. |
Aug 1973 |
E |
4378262 |
Annis, Jr. |
Mar 1983 |
A |
4516488 |
Bartzick et al. |
May 1985 |
A |
4569186 |
Mori et al. |
Feb 1986 |
A |
5267508 |
Yoshino |
Dec 1993 |
A |
5377477 |
Haberstroh et al. |
Jan 1995 |
A |
5809873 |
Chak et al. |
Sep 1998 |
A |