Information
-
Patent Grant
-
6394675
-
Patent Number
6,394,675
-
Date Filed
Monday, August 7, 200023 years ago
-
Date Issued
Tuesday, May 28, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Yan; Ren
- Crenshaw; Marvin P.
Agents
-
CPC
-
US Classifications
Field of Search
US
- 400 6152
- 400 208
- 400 231
- 400 54
- 400 621
-
International Classifications
-
Abstract
There is provided provide a tape printing apparatus which is capable of properly operating a tape feed mechanism and a tape cutting mechanism by the use of a single motor. The tape printing apparatus is capable of printing on a printing tape while feeding the printing tape by unwinding a roll of the printing tape, and cutting off a printed portion of the printing tape. A tape feed mechanism feeds the printing tape. A tape cutting mechanism cuts the printing tape. A single motor is capable of performing rotation in normal and reverse directions. A feed mechanism-side gear train transmits torque of the motor to the tape feed mechanism to cause the tape feed mechanism to operate. A cutting mechanism-side gear train transmits the torque of the motor to the tape cutting mechanism to cause the tape cutting mechanism to operate. A clutch mechanism is interposed between the motor, and the feed mechanism-side gear train and the cutting mechanism-side gear train, for performing switching operation to selectively transmit the torque of the motor in one of the normal and reverse directions to the feed mechanism-side gear train, and the torque of the motor in another of the normal and reverse directions to the cutting mechanism-side gear train.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a tape printing apparatus which is capable of printing on a printing tape while feeding the printing tape from a tape cartridge loaded therein and cutting off the printed portion of the printing tape.
2. Prior Art
In a conventional tape printing apparatus, a tape cartridge containing a roll of a printing tape and a roll of an ink ribbon is removably loaded in a main unit of the apparatus. The main unit contains a print head which faces the tape cartridge loaded in the main unit, a tape feed mechanism for simultaneously feeding both the printing tape and the ink ribbon, and a tape cutting mechanism for cutting off a printed portion of the printing tape. The tape feed mechanism feeds the printing tape and the ink ribbon in a state placed one upon the other, and the print head faces toward the printing tape and the ink ribbon fed by the tape feed mechanism, for printing on the printing tape as desired. During the printing operation, used part of the ink ribbon is taken up within the tape cartridge, and a printed portion of the printing tape alone is sent out of the main unit via a tape exit. When the printing operation is completed, the printed portion of the printing tape is cut off by the tape cutting mechanism and discharged from the apparatus. The tape feed mechanism and the tape cutting mechanism each include a motor as a drive source, and are subject to centralized control by a controller.
In the above conventional tape printing apparatus, the tape feed mechanism and the tape cutting mechanism as output ends of the driving system of the apparatus are different in the manner and timing of operation, and therefore the two mechanisms are required to be driven by respective different motors. This results in an increase in the number of component parts and space for installation of the same.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a tape printing apparatus which is capable of properly operating a tape feed mechanism and a tape cutting mechanism by the use of a single motor.
To attain the above object, the present invention provides a tape printing apparatus a tape printing apparatus which is capable of printing on a printing tape while feeding the printing tape by unwinding a roll of the printing tape, and cutting off a printed portion of the printing tape.
The tape printing apparatus according to the invention is characterized by comprising:
a tape feed mechanism for feeding the printing tape;
a tape cutting mechanism for cutting the printing tape;
a single motor which is capable of performing rotation in normal and reverse directions;
a first torque transmitting mechanism for transmitting torque of the motor to the tape feed mechanism to cause the tape feed mechanism to operate;
a second torque transmitting mechanism for transmitting the torque of the motor to the tape cutting mechanism to cause the tape cutting mechanism to operate; and
a clutch mechanism interposed between the motor, and the first torque transmitting mechanism and the second torque transmitting mechanism, for performing switching operation to selectively transmit the torque of the motor in one of the normal and reverse directions to the first torque transmitting mechanism, and the torque of the motor in another of the normal and reverse directions to the second torque transmitting mechanism.
According to this tape printing apparatus, when the motor performs normal rotation, for instance, the torque of the motor is transmitted by the clutch mechanism via the first torque transmitting mechanism to the tape feed mechanism to feed the tape, while when the motor performs reverse rotation, the torque of the motor is transmitted by the clutch mechanism via the second torque transmitting mechanism to the tape cutting mechanism to cut off the printed portion of the tape. That is, it is possible to feed the printing tape by rotation of the motor in one direction and cut off the printed portion of the tape by rotation of the same in the other direction.
Preferably, the tape printing apparatus includes an output gear from which the torque of the motor is output, and a rotational shaft on which the output gear is rigidly fitted, the first torque transmitting mechanism including a feed mechanism-side gear train for transmitting the torque of the motor to the tape feed mechanism, the feed mechanism-side gear train having an input gear, the second torque transmitting mechanism including a cutting mechanism-side gear train for transmitting the torque of the motor to the tape cutting mechanism, the cutting mechanism having an input gear, the clutch mechanism including a planet gear mating with the output gear, and a carrier having one end thereof supporting the planet gear such that the planet gear is rotatable thereon and another end thereof loosely fitted on the rotational shaft on which the output gear is rigidly fitted such that the carrier is capable of pivotal movement, by frictional drag, with rotation of the rotational shaft, the planet gear being mated with the input gear of the feed mechanism-side gear train by the rotation of the motor in the one of the normal and reverse directions, and mated with the input gear of the cutting mechanism-side gear train by the rotation of the motor in the another of the normal and reverse directions.
According to this preferred embodiment, when the motor performs the normal rotation, for instance, the carrier of the clutch mechanism pivotally moves or swings in one direction, by frictional drag, with rotation of the rotational shaft on which the output gear is fitted to cause the planet gear to automatically mate with the input gear of the feed mechanism-side gear train, whereby torque of the output gear is transmitted to the input gear of the feed mechanism-side gear train via the planet gear. On the other hand, when the motor performs the reverse rotation, the carrier of the clutch mechanism pivotally moves or swings in the other direction, by frictional drag, with rotation of the rotational shaft on which the output gear is fitted to cause the planet gear to automatically mate with the input gear of the cutting mechanism-side gear train, whereby the torque of the output gear is transmitted to the input gear of the cutting mechanism-side gear train via the planet gear. As described above, the switching between the normal and reverse rotations of the motor causes automatic switching of the clutch mechanism, and hence the supply of the driving force can be automatically switched. Further, the use of the planet gear permits the clutch mechanism to be simplified in construction.
Preferably, the tape printing apparatus includes an ink ribbon to be fed in a state placed upon the printing tape, the tape feed mechanism including a platen for feeding the printing tape and the ink ribbon in a state placed one upon another, a platen shaft for rotating the platen, a ribbon take-up reel for taking up the ink ribbon, and a ribbon take-up shaft for rotating the ribbon take-up reel, the feed mechanism-side gear train including a platen gear on which the platen shaft is coaxially secured and a take-up gear on which the ribbon take-up shaft is coaxially secured, as respective output ends thereof.
According to this preferred embodiment, by rotating the platen shaft and the ribbon take-up shaft via the platen gear and the take-up gear, respectively, the printing tape and the ink ribbon can be properly fed together in a state placed one upon the other.
More preferably, the tape cutting mechanism includes a stationary blade and a movable blade that perform relative motion therebetween for cutting operation, and a crank disk for engaging with the movable blade to cause the movable blade to effect the cutting operation, and the cutting mechanism-side gear train includes a cutter gear coaxially secured to the crank disk as an output end of the cutting mechanism-side gear train.
According to this preferred embodiment, by rotating the crank disk via the cutter gear, it is possible to cause the movable blade to perform a proper cutting operation. It is preferable that the stationary blade and the movable blade form a cutter in the form of scissors.
Further preferably, the tape printing apparatus includes a tape exit from which the printed portion of the printing tape is discharged, and a tape holding mechanism associated with the tape exit and linked to the tape cutting mechanism, for holding the printed portion cut off by the tape cutting mechanism at the tape exit.
Still more preferably, the tape printing apparatus includes a control block for controlling the rotation of the motor, and the control block controls the rotation of the motor such that when the movable blade has reached a cutting terminal portion as an end position in a cutting direction of the movable blade by the rotation of the motor in the another of the normal and reverse directions, the printed portion is held at the tape exit by the tape holding mechanism.
Even further preferably, the tape printing apparatus includes a printing block for printing on the printing tape, the motor including a rotational shaft, the crank disk having a peripheral surface and a recess formed in the peripheral surface, the recess having an arcuate profile in cross-section, the control block including an encoder arranged in proximity to the rotational shaft of the motor, for detecting a rotational angle through which the rotational shaft of the motor rotates, and a detection switch in abutment with the peripheral surface of the crank disk, the detection switch moving into the recess when the movable blade has reached a cutting wait position, and generating a cutting wait position detection signal indicative of the cutting wait position of the movable blade, the control block causing the motor to rotate in the another of the normal and reverse directions in response to a print command to thereby cause the movable blade to be pivotally moved to the cutting wait position, and in response to the cutting wait position detection signal, causing the motor to rotate in the one of the normal and reverse directions to thereby cause the movable blade to be held at the cutting wait position and at the same time cause the tape feeding mechanism to feed the printing tape, and upon termination of the printing, the control block causing the motor to rotate in the another of the normal and reverse directions to cause the movable blade to be pivotally moved from the cutting wait position to the cutting terminal position until the encoder detects a predetermined rotational angle through which the rotational shaft of the motor has rotated when the movable blade has reached the cutting terminal position, and then causing the motor to stop to thereby cause the tape holding mechanism to hold the printed portion of the printing tape at the tape exit.
The above and other objects, features, and advantages of the invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a perspective view of a tape printing apparatus according to an embodiment of the invention;
FIG. 2
is a perspective view of a cartridge compartment of the
FIG. 1
tape printing apparatus and component parts associated with the cartridge compartment, as viewed from a cutter side;
FIG. 3
is a perspective view of the
FIG. 2
cartridge compartment and component parts associated therewith, as viewed from a motor side;
FIG. 4
is a perspective view of a whole drive system of the
FIG. 1
tape printing apparatus;
FIG. 5
is a perspective view of a gear train of the
FIG. 4
drive system;
FIGS. 6A and 6B
are enlarged plan views of a clutch mechanism of the
FIG. 4
drive system and component parts associated with the clutch mechanism;
FIG. 7
is an enlarged perspective view of a tape cutting mechanism of the
FIG. 4
drive system and component parts associated with the tape cutting mechanism;
FIG. 8
is a perspective view of a tape strip-holding mechanism of the
FIG. 1
tape printing apparatus and component parts associated with the tape strip-holding mechanism; and
FIGS. 9A and 9B
are enlarged plan views of the
FIG. 8
tape strip-holding mechanism and component parts associated therewith.
DETAILED DESCRIPTION
The invention will now be described in detail with reference to drawings showing a tape printing apparatus according to an embodiment thereof. The tape printing apparatus prints on a strip of printing tape as desired according to key entries and cuts off the printed portion of the printing tape. The cut-off strip of the printing tape is used as a label to be affixed to a file, a cable, or the like. That is, the tape printing apparatus makes a label printed with characters from plain printing tape. The plain printing tape and an ink ribbon to be consumed in the tape printing are contained in a tape cartridge, and fed to the main unit of the apparatus from the tape cartridge.
Referring first to
FIG. 1
, the tape printing apparatus
1
is a hand-held type whose main unit
2
has an apparatus casing
3
forming an outer shell of the main unit
2
. The tape printing apparatus
1
has a key entry block
4
arranged at a front portion thereof and a lid
6
arranged at a rear portion thereof. The lid
6
incorporates a liquid crystal display
5
forming the outer surface of the lid
6
. As shown in
FIGS. 2 and 3
, arranged under the lid
6
is a cartridge compartment
8
for accommodating a tape cartridge
7
. Further, the apparatus casing
3
has a left side portion thereof formed with a tape exit
10
for communication between the cartridge compartment
8
and the outside of the apparatus
1
, and a cutter
11
faces the tape exit
10
, for cutting off a dispensed portion of the printing tape T (see FIGS.
1
and
2
).
In the cartridge compartment
8
, there are erected a print head
14
covered with a head cover
13
, a platen shaft
15
opposed to the print head
14
, a take-up shaft
16
for taking up used part of the ink ribbon, and a guide projection
17
for guiding the tape cartridge
7
in the cartridge compartment
8
when it is mounted therein. A platen
18
for engagement with the platen shaft
15
is arranged in the tape cartridge
7
(see FIG.
1
).
The platen
18
, the platen shaft
15
, and the take-up shaft
16
form a tape feed mechanism
21
together with other components, referred to hereinafter, associated with the components
18
,
15
,
16
, while the cutter
11
forms a tape cutting mechanism
22
together with other components, referred to hereinafter, associated with the cutter
11
. The tape feed mechanism
21
and the tape cutting mechanism
22
are driven for operation by an identical drive source (motor) via a torque transmitting mechanism
23
and a clutch mechanism
24
arranged under the cartridge compartment
8
(which will be described in detail hereinafter). Further, the tape exit
10
incorporates a tape strip-holding mechanism
25
for holding a tape strip Ta at the tape exit
10
by pressing the same against a side wall of the tape exit
10
(which will also be described in detail hereinafter).
When a label is produced by using the tape printing apparatus
1
, first, the lid
6
is opened, and then the tape cartridge
7
is pushed into the cartridge compartment
8
from above. When the loading of the tape cartridge
7
is completed, the lid
6
is closed to place the tape printing apparatus
1
in a printing wait state. Then, the user enters desired characters and figures by operating the key entry block
4
while watching the liquid crystal display
5
. When the entry of the desired characters and figures is verified on the liquid crystal display
5
, the key entry block
4
is further operated to input a print command.
When the print command is issued, the printing tape T and the ink ribbon contained in the tape cartridge
7
start to be rolled out simultaneously, and printing is effected on the printing tape T by the print head
14
in a desired manner. During the printing operation, used part of the ink ribbon is taken up within the tape cartridge
7
, while a printed portion of the printing tape T is sent out of the apparatus
1
via the tape exit
10
. When the printing operation is completed, the printing tape T is further fed by an amount corresponding to a trailing blank space or margin, and then the feed of the printing tape T and the ink ribbon is stopped. Then, the tape cutting mechanism
22
operates to cause the cutter
11
to cut off the printed portion of the printing tape T. The tape strip Ta cut off by the cutter
11
is held at the tape exit
10
such that it can be manually drawn out from the tape exit
10
.
Next, the drive system of the apparatus
1
having the tape feed mechanism
21
and the tape cutting mechanism
22
as output ends of the driving system will be described in detail with reference to
FIGS. 4 and 5
. The drive system includes a motor
31
, a driving block
32
comprised of a gear train linked to a main shaft of the motor
31
, the clutch mechanism
24
linked to the driving block
32
, the torque transmitting mechanism
23
comprised of a feed mechanism-side gear train
33
and a cutting mechanism-side gear train
34
with one of which the clutch mechanism
24
is selectively engaged, the tape feed mechanism
21
linked to the feed mechanism-side gear train
33
, and the tape cutting mechanism
22
linked to the cutting mechanism-side gear train
34
. The motor
31
, the driving block
32
, the clutch mechanism
24
, and the torque transmitting mechanism
23
are mounted on a base frame
26
arranged in a space under the cartridge compartment
8
.
The motor
31
is capable of rotating in normal and reverse directions. When the motor
31
performs normal rotation, the torque is transmitted from the driving block
32
to the clutch mechanism
24
, and the clutch mechanism
24
switches to be connected with the feed mechanism-side gear train
33
to further transmit the torque to the feed mechanism-side gear train
33
and the tape feed mechanism
21
. As a result, the platen shaft
15
and the take-up shaft
16
are rotated to feed the printing tape T and the ink ribbon simultaneously. On the other hand, when the motor
31
performs reverse rotation, the torque is transmitted from the driving block
32
to the clutch mechanism
24
, and the clutch mechanism
24
switches to be connected with the cutting mechanism-side gear train
34
to further transmit the torque to the cutting mechanism-side gear train
34
and the tape cutting mechanism
22
. As a result, the cutter
11
is operated to cut the printing tape T.
The motor
31
is formed by a DC motor and secured to the base frame
26
in a state slightly tilted with respect to the base frame
26
in view of space efficiency within the apparatus casing
3
. The driving block
32
is comprised of a worm
36
rigidly fitted on the main shaft of the motor
31
, a worm wheel
37
mating with the worm
36
, a thick gear (output gear)
38
having a relatively large thickness and coaxially secured to the underside of the worm wheel
37
, and a rotational shaft
39
on which the worm wheel
37
and the thick gear
38
are rigidly fitted (see FIGS.
6
A and
6
B). The torque of the motor
31
is transmitted via the worm
36
and the worm wheel
37
to the thick gear
38
from which the torque is input to the clutch mechanism
24
.
As shown in
FIGS. 6A and 6B
, the clutch mechanism
24
includes a planet gear
40
mating with the thick gear
38
and a carrier
41
which has an end portion rotatably supporting the planet gear
40
and is loosely fitted on the rotational shaft
39
in a manner movable with rotation of the shaft
39
by frictional drag therewith. When the motor
31
rotates in the normal direction, the worm wheel
37
and the thick gear
38
rotate in unison with the rotational shaft
39
. When the rotational shaft
39
rotates, the carrier
41
is caused to rotate (or swing), by frictional drag, with the rotation of the rotational shaft
39
to cause the planet gear
40
to mate with an input gear
42
of the feed mechanism-side gear train
33
. The torque of the thick gear
38
is transmitted to the planet gear
40
mating therewith, and then to the input gear
42
via the planet gear
40
at a time point the planet gear
40
has mated with the input gear
42
, thereby causing rotation of the input gear
42
(see FIG.
6
A). On the other hand, when the motor
31
performs reverse rotation, the rotational shaft
39
rotates in the reverse direction, whereby the carrier
41
rotates (or swings) to cause the planet gear
40
to mate with an input gear
43
of the cutting mechanism-side gear train
34
. The torque of the thick gear
38
is transmitted to the planet gear
40
, and then to the input gear
43
via the planet gear
40
at a time point the planet gear
40
has mated with the input gear
43
, thereby causing rotation of the input gear
43
(see FIG.
6
B).
The feed mechanism-side gear train
33
is comprised of the input gear
42
, a first intermediate gear
45
coaxially secured to the top of the input gear
42
, a second intermediate gear
46
mating with the first intermediate gear
45
, a branching gear
47
coaxially secured to the underside of the second intermediate gear
46
, a take-up gear
48
arranged on a take-up shaft side and mating with the branching gear
47
, a reduction gear
49
arranged on a platen shaft side and also mating with the branching gear
47
, and a platen gear
50
mating with the reduction gear
49
.
The torque of the motor
31
input to the input gear
42
is transmitted to the first and second intermediate gears
45
,
46
and then branched at the branching gear
47
to rotate the take-up gear
48
and the reduction gear
49
. It should be noted that when torque is input to the platen gear
50
e.g. in the case of the printing tape T being drawn out by the user, the input gear
42
pushes the planet gear
40
away to thereby prevent transmission of this torque and at the same time causes rotation of the take-up gear
48
via the branching gear
47
without receiving any load from the motor
31
. As a result, the ink ribbon is taken up by the take-up reel
16
as the printing tape T is drawn out, which prevents the ink ribbon from becoming loose.
The cutting mechanism-side gear train
34
is comprised of the input gear
43
, an input bevel gear
52
coaxially secured to the top of the input gear
43
, an output bevel gear
53
mating with the input bevel gear
52
, a long shaft
54
having the output bevel gear
53
rigidly fitted on one end thereof, an intermediate gear
55
rigidly fitted on the other end of the shaft
54
, and a cutter gear
56
mating with the intermediate gear
55
. The torque of the motor
31
input to the input gear
43
is transmitted to the shaft
54
via the two bevel gears
52
,
53
, and then to the intermediate gear
55
via the shaft
54
to cause rotation of the cutter gear
56
.
The tape feed mechanism
21
includes the platen
18
in rolling contact with the printing tape T and the ink ribbon, for feeding them, the platen shaft
15
for rotating the platen
18
, and the take-up shaft
16
for taking up the ink ribbon. The platen
18
is incorporated in the tape cartridge
7
and brought into engagement with the platen shaft
18
when the tape cartridge
7
is loaded in the cartridge compartment
8
. The platen shaft
15
is coaxially and fixedly attached to the platen gear
50
in a cantilever manner. The platen shaft
15
rotates in unison with the platen gear
50
to rotate the platen
18
engaging with the platen shaft
15
. The take-up shaft
16
is coaxially and fixedly attached to the take-up gear
48
in a cantilever manner. The take-up shaft
16
receiving torque from the take-up gear rotates in unison therewith to cause rotation of a reel core of the ink ribbon engaging with the take-up shaft
16
. The take-up shaft
16
is a sliding shaft which causes rotation of the reel core of the ink ribbon by frictional drag while properly sliding thereon to thereby cause the same to take up the ink ribbon.
As shown in
FIG. 7
, the tape cutting mechanism
22
includes the cutter
11
in the form of scissors and a crank disk
58
engaging with the cutter
11
to cause the same to perform a cutting operation. The cutter
11
is comprised of a stationary blade
61
and a movable blade
62
. The two blades
61
,
62
are coupled to each other by a pivot
63
such that the movable blade
62
can be pivotally moved to perform cutting operations on the stationary blade
61
. The stationary blade
61
is comprised of a blade body
65
and a cutter arm
66
integrally formed with the blade body
65
and extending from the root of the blade body
65
substantially perpendicularly with respect to the same. The stationary blade
61
is attached to the base frame
26
by fixing the cutter arm
66
to the base frame
26
. Attached to the blade body
65
of the stationary blade
61
are an oil absorber
67
containing silicone oil for preventing an adhesive on the printing tape T from adhering to the blade body
65
and a static-eliminating brush
68
for establishing a ground for generated static electricity (see FIG.
4
).
The movable blade
62
is comprised of a blade body
70
and a cutter arm
71
integrally formed with the blade body
70
and extending from the root of the blade body
70
substantially perpendicularly with respect to the same, and the cutter arm
71
is formed with a slot
72
for constant engagement with the crank disk
58
. The crank disk
58
is comprised of a disk body
74
and a crankpin
75
integrally formed on the disk body
74
at a location offset from the center of the same. The cutter gear
56
is coaxially secured to the reverse side of the crank disk
58
(see FIG.
4
). The crankpin
75
is inserted into the slot
72
of the cutter arm
71
for engagement therewith. That is, the crank disk
58
and the cutter arm
71
form a wobble crank mechanism in which a rotation of the crank disk
58
causes the blade body
70
to perform a cutting operation (reciprocating motion) between a cutting terminal position (forward end position) at which the blade body
70
has slid on the stationary blade
61
and a cutting wait position (rearward end position) at which the blade body
70
is positioned farthest from the stationary blade
61
.
It should be noted that, as described in detail hereinafter, a switch end
105
a
of a detection switch
105
is held in sliding contact with the outer peripheral surface of the crank disk
58
which is formed with an arcuate recess
76
for turning on the detection switch
105
.
Next, the tape strip-holding mechanism
25
will be described in detail with reference to
FIGS. 8 and 9A
,
9
B. As shown in
FIG. 8
, the tape exit
10
formed in the apparatus casing
3
as described hereinbefore is formed by a slit
81
having an open upper end, and an expanding opening
82
spreading outward from the slit
81
in a manner broadening toward the outer end of the tape exit
10
. A portion of the apparatus casing
3
formed with the slit
81
contains the cutter
11
which performs a cutting operation along a cutting line substantially coincident with a center line of the slit
81
. Further, the tape strip-holding mechanism
25
is arranged at a location inward (rightward as viewed in
FIGS. 9A and 9B
) of a movable blade-side opening wall
83
b
of the apparatus casing
3
forming a wall of the expanding opening
82
, for pressing a cut-off tape strip Ta against a stationary blade-side opening wall
83
a.
The tape strip-holding mechanism
25
includes a holding nail
91
for holding a tape strip Ta by pressing the same against the opening wall
83
a
, a nail holder
92
in the form of a case, for supporting the holding nail
91
such that it can reciprocate, and a coiled spring
93
for urging the holding nail
91
toward the opening wall
83
a
. The holding nail
91
is comprised of a nail
94
slidably extending through a hole formed through the movable blade side opening wall
83
b
and a hole formed through the wall of the nail holder
92
, an engaging projection
95
extending inward from the root of the nail
94
, and a rod
96
extending linearly from the extreme root end of the nail
94
and including a reduced-diameter portion
96
a
slidably extending through a hole formed through the wall of the nail holder
92
, all of which are integrally formed as a unitary member. The holding nail
91
has forward and rearward portions, i.e. the nail
94
and the reduced-diameter portion
96
a
of the rod
96
supported by the nail holder
92
such that the nail
94
can reciprocate between its holding position at which the nail
94
is held in abutment against the stationary blade-side opening wall
83
a
in a state projected from the movable blade-side opening wall
83
b
and its release position at which the nail
94
is in a state retracted toward the inside of the movable blade-side opening wall
83
b.
The holding nail
91
has a forward end face formed with a bevel such that it meets the surface of the stationary blade-side opening wall
83
a
. More specifically, the forward end face of the holding nail
91
is formed to have a shape complementary to that of the stationary blade-side opening wall
83
a
such that the forward end face can be held in surface contact with the surface of the opening wall
83
a
. Fitted on the rod
96
is the coiled spring
93
urging the holding nail
91
in a forward or projecting direction, with one end thereof held in abutment with the root end of the nail
94
and the other end thereof in abutment with an inner wall of the nail holder
92
. The engaging projection
95
of the holding nail
91
urged as above is in contact with the back of the movable blade
62
. Accordingly, the holding nail
91
moves forward and backward according to the cutting operation (pivotal reciprocating motion) of the movable blade
62
to project and retract through the movable blade-side opening wall
83
b
. It is preferable that the holding nail
91
reaches its holding position immediately before the movable blade
62
reaches its cutting terminal position.
In this preferred case, at the instant (which can be not exactly “the instant”) of the cutter
11
having cut off the printing tape T, the holding nail
91
reaches the stationary blade-side opening wall
83
a
to hold a cut-off tape strip Ta between the surface of the stationary blade-side opening wall
83
a
and itself. This held or sandwiched state of the tape strip Ta is maintained until the next cutting operation starts. Therefore, in the present embodiment, in order to hold the holding nail
91
at its holding position, the cutting operation of the movable blade
61
is stopped when the movable blade
62
reaches its cutting terminal position, and a next cutting operation is started from the cutting terminal position of the movable blade.
Now, description will be made, with reference to
FIG. 2
, of a control system for causing the movable blade
62
to stop at its cutting terminal position. The control system (control means) includes a CPU
101
for centralized control of the motor
31
and the input/output devices, and a detector
102
for detecting a position of the movable blade
62
during a cutting operation. The detector
102
is comprised of an encoder
104
arranged in proximity to the main shaft of the motor
31
, and the detection switch
105
arranged in proximity to the outer peripheral surface of the crank disk
58
of the tape cutting mechanism
22
. The encoder
104
detects a rotational angle of the motor
31
, while the detection switch
105
detects the cutting wait position of the movable blade
62
in cooperation with the recess
76
of the crank disk
58
.
Before the start of printing, the movable blade
62
is in the cutting terminal position. In response to a print command, the CPU
101
causes the motor
31
to start reverse rotation. At this time, the torque of the motor
31
is transmitted by the clutch
24
to the cutting mechanism side to cause the rotation of the crank disk
58
whereby the movable blade
62
is pivotally moved toward the cutting wait position. When the switch end
105
a
of the detection switch
105
is let in the recess
76
, the detection switch
105
is turned on to send a detection signal indicative of the sensed cutting wait position of the cutter
11
(movable blade
62
) to the CPU
101
. In response to the signal, the CPU
101
resets the encoder
104
, and at the same time switches the rotation of the motor
31
from the reverse rotation to the normal rotation. According to this switching of the direction of rotation of the motor
31
, the clutch mechanism
24
operates to cause the torque of the motor
31
to be transmitted to the tape feed mechanism
21
side. As a result, the movable blade
62
is maintained at the cutting wait position, and on the other hand, the printing on the printing tape T is carried out while feeding the printing tape T and the ink ribbon and causing the ink ribbon to be take up. When the printing is completed and further an additional feed of the printing tape T corresponding to a predetermined margin is completed, the CPU
101
switches the rotation of the motor
31
from the normal rotation to the reverse rotation. According to this switching, the clutch mechanism
24
operates to cause the torque of the motor
31
to be transmitted to the cutting mechanism
22
side. This causes the rotation of the crank disk
58
to be resumed, and the cutter in engagement with therewith is operated to cut off the printing tape. Almost simultaneously to this cutting of the printing tape, the encoder
104
detects that the crank disk
58
has rotated through a rotational angle corresponding to a half rotational turn thereof, and delivers a signal indicative of the sensed cutting terminal position of the movable blade
62
to the CPU
101
. In response to this signal, the CPU
101
stops the rotation of the motor
31
, whereby the movable blade is held at the cutting terminal position. That is, the cutting wait position is set as a home position of the cutter
11
(movable blade
62
), and the movable blade
62
is stopped when it has pivotally moved to the cutting terminal position from the home position. Subsequently, when a print command instructing a next printing operation is received, the CPU
101
causes the reverse rotation of the motor
31
to be resumed, whereby the movable blade
62
is returned to its cutting wait position and held in the wait state. Upon completion of the printing operation, it is again caused to pivotally move to its cutting terminal position.
As described above, according to the present embodiment, since the tape feed mechanism
21
and the tape cutting mechanism
22
are both driven by the single motor
31
and by utilizing the normal and reverse rotations of the same, it is possible to reduce the number of motors by one and reduce space conventionally required for installment of two motors by half. This contributes to reduction of the manufacturing costs and size of the apparatus. Further, the use of the clutch mechanism which can be switched automatically by the normal and reverse rotations of the motor
31
makes it possible to dispense with a special mechanism for switching driving forces and hence simplify the construction of the apparatus.
It should be noted that a one-way clutch or the like may be used as the clutch mechanism.
It is further understood by those skilled in the art that the foregoing are preferred embodiments of the invention, and that various changes and modification may be made without departing from the spirit and scope thereof.
Claims
- 1. A tape printing apparatus which is capable of printing on a printing tape while feeding said printing tape by unwinding a roll of said printing tape, and cutting off a printed portion of said printing tape,the tape printing apparatus comprising: a tape feed mechanism for feeding said printing tape; a tape cutting mechanism for cutting said printing tape; a single motor which is capable of performing rotation in normal and reverse directions; a first torque transmitting mechanism for transmitting torque of said motor to said tape feed mechanism to cause said tape feed mechanism to operate; a second torque transmitting mechanism for transmitting said torque of said motor to said tape cutting mechanism to cause said tape cutting mechanism to operate; and a clutch mechanism interposed between and selectively coupling said motor to said first torque transmitting mechanism and to said second torque transmitting mechanism, the clutch mechanism performing switching operation to selectively transmit said torque of said motor to said first torque transmitting mechanism when said motor rotates in one of said normal and reverse directions, and to transmit said torque of said motor to said second torque transmitting mechanism when said motor rotates in another of said normal and reverse directions.
- 2. A tape printing apparatus according to claim 1, including an output gear from which said torque of said motor is output, and a rotational shaft on which said output gear is rigidly fitted, andwherein said first torque transmitting mechanism includes a feed mechanism-side gear train for transmitting said torque of said motor to said tape feed mechanism, said feed mechanism-side gear train having an input gear, and said second torque transmitting mechanism includes a cutting mechanism-side gear train for transmitting said torque of said motor to said tape cutting mechanism, said cutting mechanism having an input gear, wherein said clutch mechanism includes a planet gear mating with said output gear, and a carrier having one end thereof supporting said planet gear such that said planet gear is rotatable thereon and another end thereof loosely fitted on said rotational shaft on which said output gear is rigidly fitted such that said carrier is capable of pivotal movement, by frictional drag, with rotation of said rotational shaft, said planet gear being mated with said input gear of said feed mechanism-side gear train by said rotation of said motor in said one of said normal and reverse directions, and mated with said input gear of said cutting mechanism-side gear train by said rotation of said motor in said another of said normal and reverse directions.
- 3. A tape printing apparatus according to claim 2, including an ink ribbon to be fed in a state placed upon said printing tape,wherein said tape feed mechanism includes a platen for feeding said printing tape and said ink ribbon in a state placed one upon another, a platen shaft for rotating said platen, a ribbon take-up reel for taking up said ink ribbon, and a ribbon take-up shaft for rotating said ribbon take-up reel, and said feed mechanism-side gear train including a platen gear on which said platen shaft is coaxially secured and a take-up gear on which said ribbon take-up shaft is coaxially secured, as respective output ends thereof.
- 4. A tape printing apparatus according to claim 2, wherein said tape cutting mechanism includes a stationary blade and a movable blade that perform relative motion therebetween for cutting operation, and a crank disk for engaging with said movable blade to cause said movable blade to effect said cutting operation, andsaid cutting mechanism-side gear train including a cutter gear coaxially secured to said crank disk as an output end of said cutting mechanism-side gear train.
- 5. A tape printing apparatus according to claim 3, wherein said tape cutting mechanism includes a stationary blade and a movable blade that perform relative motion therebetween for cutting operation, and a crank disk for engaging with said movable blade to cause said movable blade to effect said cutting operation, andsaid cutting mechanism-side gear train including a cutter gear coaxially secured to said crank disk as an output end of said cutting mechanism-side gear train.
- 6. A tape printing apparatus according to claim 4, including a tape exit from which said printed portion of said printing tape is discharged, and a tape holding mechanism associated with said tape exit and linked to said tape cutting mechanism, for holding said printed portion cut off by said tape cutting mechanism.
- 7. A tape printing apparatus according to claim 5, including a tape exit from which said printed portion of said printing tape is discharged, and a tape holding mechanism associated with said tape exit and linked to said tape cutting mechanism, for holding said printed portion cut off by said tape cutting mechanism at said tape exit.
- 8. A tape printing apparatus according to claim 6, including a control block for controlling the rotation of said motor, and wherein said control block controls the rotation of said motor such that when said movable blade has reached a cutting terminal portion as an end position in a cutting direction of said movable blade by said rotation of said motor in said another of said normal and reverse directions, said printed portion is held at said tape exit by said tape holding mechanism.
- 9. A tape printing apparatus according to claim 7, including a control block for controlling the rotation of said motor, and wherein said control block controls the rotation of said motor such that when said movable blade has reached a cutting terminal portion as an end position in a cutting direction of said movable blade by said rotation of said motor in said another of said normal and reverse directions, said printed portion is held at said tape exit by said tape holding mechanism.
- 10. A tape printing apparatus according to claim 8, including a printing block for printing on said printing tape, and wherein said motor includes a rotational shaft, and wherein said crank disk has a peripheral surface and a recess formed in said peripheral surface, said recess having an arcuate profile in cross-section, and wherein said control block includes an encoder arranged in proximity to said rotational shaft of said motor, for detecting a rotational angle through which said rotational shaft of said motor rotates, and a detection switch in abutment with said peripheral surface of said crank disk, said detection switch moving into said recess when said movable blade has reached a cutting wait position, and generating a cutting wait position detection signal indicative of said cutting wait position of said movable blade, and wherein said control block causes said motor to rotate in said another of said normal and reverse directions in response to a print command to thereby cause said movable blade to be pivotally moved to said cutting wait position, and in response to said cutting wait position detection signal, causes said motor to rotate in said one of said normal and reverse directions to thereby cause said movable blade to be held at said cutting wait position and at the same time cause said tape feeding mechanism to feed said printing tape, and wherein upon termination of said printing, said control block causes said motor to rotate in said another of said normal and reverse directions to cause said movable blade to be pivotally moved from said cutting wait position to said cutting terminal position until said encoder detects a predetermined rotational angle through which said rotational shaft of said motor has rotated when said movable blade has reached said cutting terminal position, and then causes said motor to stop to thereby cause said tape holding mechanism to hold said printed portion of said printing tape at said tape exit.
- 11. A tape printing apparatus according to claim 9, including a printing block for printing on said printing tape, and wherein said motor includes a rotational shaft, and wherein said crank disk has a peripheral surface and a recess formed in said peripheral surface, said recess having an arcuate profile in cross-section, and wherein said control block includes an encoder arranged in proximity to said rotational shaft of said motor, for detecting a rotational angle through which said rotational shaft of said motor rotates, and a detection switch in abutment with said peripheral surface of said crank disk, said detection switch moving into said recess when said movable blade has reached a cutting wait position, and generating a cutting wait position detection signal indicative of said cutting wait position of said movable blade, and wherein said control block causes said motor to rotate in said another of said normal and reverse directions in response to a print command to thereby cause said movable blade to be pivotally moved to said cutting wait position, and in response to said cutting wait position detection signal, causes said motor to rotate in said one of said normal and reverse directions to thereby cause said movable blade to be held at said cutting wait position and at the same time cause said tape feeding mechanism to feed said printing tape, and wherein upon termination of said printing, said control block causes said motor to rotate in said another of said normal and reverse directions to cause said movable blade to be pivotally moved from said cutting wait position to said cutting terminal position until said encoder detects a predetermined rotational angle through which said rotational shaft of said motor has rotated when said movable blade has reached said cutting terminal position, and then causes said motor to stop to thereby cause said tape holding mechanism to hold said printed portion of said printing tape at said tape exit.
- 12. A tape printing apparatus according to claims 6 or 7, wherein said tape holding mechanism includes a holding nail for holding said printed portion by pressing the same against a stationary blade-side opening wall of said tape exit, a nail holder in the form of a case supporting the holding nail for reciprocating movement, and a coil spring for urging said holding nail toward said stationary blade-side opening wall.
- 13. A tape printing apparatus according to claim 12, wherein said holding nail is comprised of a nail slidably extending through a first hole formed through a movable blade side opening wall and a second hole formed through a wall of said nail holder, and a rod extending linearly from an extreme root end of said nail and including a reduced-diameter portion slidably extending through a third hole formed through said wall of said nail holder.
- 14. A tape printing apparatus according to claim 13, wherein said holding nail has forward and rearward portions, said nail formed in said forward portion and said reduced-diameter portion of said rod formed in said rearward portion are supported by said nail holder so that said holding nail can reciprocate between a holding position at which said nail is held in abutment against said stationary blade-side opening wall in a state projected from said movable blade-side opening wall via said first hole and a release position at which said nail is in a retracted state toward an inside of said movable blade-side opening wall via said first hole.
- 15. A tape printing apparatus according to claim 14, wherein said holding nail has a forward end face formed to have a shape complementary to that of said stationary blade-side opening wall such that said forward end face can be held in surface contact with a surface of said stationary blade-side opening wall.
- 16. A tape printing apparatus according to claim 14, wherein said holding nail further comprises an engaging projection extending inward from the root of said nail, said coil spring fitted on said rod urges said nail in said projecting direction with one end of said nail held in abutment with said root of said nail and the other end of said nail held in abutment with an inner wall of said nail holder, and said engaging projection of said holding nail is in contact with a back of said movable blade, and thereby said holding nail moves forward and backward according to the cutting operation of said movable blade to project and retract through said first hole of said movable blade-side opening wall.
Priority Claims (1)
Number |
Date |
Country |
Kind |
11-228885 |
Aug 1999 |
JP |
|
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