Winding core holding mechanism, roll medium holding device having the same, and winding device using said mechanism and device

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a winding core holding mechanism for supporting a winding core on which a thin medium such as paper, film or cloth is wound in a roll, relates to a roll medium holding device having the winding core holding mechanism, and relates to a winding device using those. More specifically, the present invention relates to a winding core holding mechanism suitable for supporting a winding core on which a roll paper output by a large-scale printer is wound, and a winding device using this. Also, the present invention relates to a roll medium holding device suitable for holding a roll paper output by a large-scale printer, and a winding device using this.

2. Description of the Related Art

Normally used as drawing media for large-scale full color printers (of ink jet or electrostatic recording types) are papers, films, or cloths wound on a pipe-like paper tube made of cardboard. One of the means for storing a printed medium is to wind a printed medium

100

on a paper tube

102

by a winding device

101

to store the medium

100

in a roll, as illustrated in

FIGS. 26 and 27

.

In a device for supplying the medium

100

to a printer

104

(not illustrated) or in the winding device

101

, the roll medium

100

is held such that the paper tube

102

, on which the medium

100

is wound, is sandwiched by winding core holding members

103

from both sides. Also, the paper tube

102

to be installed in the winding device

101

is the same kind as the paper tube

102

of the medium used in the supply side.

There are two kinds of paper tubes that are normally used according to the hardness and winding characteristics of the medium

100

: of 2-inch or 3-inch diameter. In order to hold two kinds of paper tubes

102

in a single winding device

101

, the 2-inch core holding member and the 3-inch core holding member are interchangeably used through attachment/detachment thereof. Otherwise, as illustrated in

FIG. 28

, a 2-inch core holding portion

115

is formed on one side of the winding core holding member

103

and a 3-inch core holding portion

106

is formed on the other.

Since the paper tube

102

is made of cardboard, the inner diameter of the paper tube

102

varies by about 2.5 mm. For example, the inner diameter of a φ2 inch paper tube may vary within the range 450 mm to +52.5 mm. For this reason, a holding portion

103

a

of the winding core holding member

103

is made in a conical shape to hold the paper tube

102

with the tapered surface so that the paper tube is centered and held even if the inner diameter of the tube

102

is not uniform.

Furthermore, the medium

100

is output in sizes of B

0

, A

0

through A

2

, for example. Therefore, roll media of various widths are on the market to meet these size requirements. To meet with media

100

of different widths, one of the winding core holding members

103

may be configured capable of sliding with respect to a stay in the axial direction of the paper tube

102

, i.e., in the width direction W of the medium

100

, as illustrated in FIG.

30

.

To hold the paper tube

102

using the above, the winding core holding member

103

is slid in the width direction W according to the width of the medium

100

to sandwich the paper tube

102

. A knob

105

is turned to secure the winding core holding member to the stay

106

so that the winding core holding member

103

will not become loose and the paper tube

102

will not come off. Although the winding core holding member

103

is secured by a screw in this example, a pin may be used as a position fixing means to secure the winding core holding member

103

to the stay

106

.

However, using this winding core holding member

103

, the components need to be changed according to the diameter of the paper tube

102

as illustrated in FIG.

28

. This results in poor operability due to complicated attaching and detaching operations. Also, a cap, fixture, etc. may be lost during the operation of the attaching/detaching of the components. Moreover, because the winding core holding member

103

uses two different components depending on the size of the paper tube

102

, one of the components which is not in use may be lost while the other component is in use.

Furthermore, since the winding core holding member

103

supports the non-uniform inner diameter of the paper tube

102

with the tapered surface of the holding portion

103

a

, the position on the tapered surface to stop the paper tube

102

varies depending on the size of the inner diameter of the tube

102

. Therefore, although the paper tube

102

is centered, the end face

102

a

thereof in the width direction W cannot be constantly positioned at the same position in the width direction W. For this reason, the center of the winding position of the paper tube

102

is shifted from the center of the winding core of the medium

100

output by the printer

104

. If the front end of the medium

100

is set and attached along the width of the paper tube

102

and winding is started under this condition, the medium

100

easily wanders off, making a winding-up difficult. In view of this, a paper tube

102

slightly longer than the width of the medium

100

needs to be used. With this, however, a winding core which is exclusively used for the winding purpose should be used for every medium of different width. This results in complicated storing and managing of the cores. Also, the paper tube

102

that was used in the supply side cannot be recycled. Moreover, the paper tube

102

has ends which stick out of the edges of the roll medium after winding-up.

In addition, when the winding core holding member

103

is positioned and fixed by a rotation of the knob

105

or by a pin, two different sliding and locking/unlocking operations are required for moving/locking or unlocking/moving the winding core holding member

103

. This results in poor operability. Particularly, to move the winding core holding member

103

to detach the medium

100

after winding, the heavy wound-up roll medium

100

is handled with a single hand. Thus, he operation becomes troublesome.

If a winding core is used exclusively for a winding purpose, instead of using the recycled paper tube

102

, the winding core may be easily attached/detached to the winding device

101

or to the printer

104

. With this, however, a winding core needs to be prepared for every medium of different width. This results in complicated storing and maintaining of the components, and also the paper tube

102

that is no longer needed in the supply side will be wasted.

OBJECT AND SUMMARY OF THE INVENTION

Then, a primary object of the present invention is to provide a winding core holding mechanism which can hold two kinds of winding cores of different sizes without changing components and can position both kinds of winding cores at a predetermined reference position, and a winding device using the core holding mechanism.

Another object of the present invention is to provide a roll medium holding device which can easily attach/detach a winding core such as a paper tube, and a winding device using the roll medium holding device.

To achieve the above objects, the present invention provides a winding core holding mechanism for holding at least one of the end portions of a winding core on which a thin medium such as paper, film, or cloth is wound, comprising a base fixed in the axial direction of the winding core, a larger diameter reference portion, which is capable of axially moving in and out of the base and which abuts to an end face of the winding core, a tapered larger diameter centering portion, which is capable of axially moving in and out of the larger diameter reference portion and which fits into the winding core of larger diameter, a smaller diameter reference portion, which is capable of axially moving in and out of the base and which abuts to an end face of the winding core of smaller diameter, and a tapered smaller diameter centering portion, which is capable of axially moving in and out of the smaller diameter reference portion and which fits into the winding core of smaller diameter. With this invention, to hold the winding core of larger diameter, the larger diameter centering portion centers the winding core while falling into the larger diameter reference portion, and the larger diameter reference portion falls into the base to position the end face at a predetermined reference position with respect to the base; to hold the winding core of smaller diameter, the smaller diameter centering portion centers the winding core while falling into smaller diameter reference portion, and the smaller diameter reference portion, the larger diameter reference portion, and the larger diameter centering portion fall into the base to position the end face at the reference position.

Thus, the winding core of larger diameter is centered by the larger diameter centering portion and is positioned at the reference position by the larger diameter reference portion. The winding core of smaller diameter is centered by the smaller diameter centering portion and is positioned at the reference position by the smaller diameter reference portion. The winding cores of both larger diameter and smaller diameter can be held in this manner without changing the components. This improves operability and eliminates a complicated management of the components.

Also, the reference position for the winding core can be always at the same position regardless of the size of the attached winding core. Therefore, when the winding core holding mechanism is used in a printer or a winding device, the position of the medium output by the printer is easily aligned with the position of the winding core. This prevents the medium from an oblique winding.

Further, each reference portion supports the winding core by the end face, and each centering portion centers the core with the tapered surface thereof. Therefore, even if the inner diameter of the winding core is not uniform, the center of rotation is first centered, and then the winding core end face is always set at the reference position.

The invention further provides a winding device for winding a thin medium such as paper, film, or cloth output by a printer on a winding core, comprising the winding core holding mechanism as described above to hold the winding core.

Therefore, the reference edges of the medium supplied by the printer can be easily aligned with the reference position on the winding side. This prevents the medium from an oblique winding.

To achieve the above objects, the invention also provides a roll medium holding device that has a winding core holding mechanism for holding one end of a winding core of a thin medium such as paper, film, or cloth wound in a roll, a slider portion fixed to the winding core holding mechanism, and a guiding portion for supporting the slider portion to be capable of sliding along the width direction of the medium, comprising a locking means that locks the slider portion from sliding in the direction away from the winding core, and an unlocking means that unlocks the locking means.

To attach the winding core, the slider portion is pushed and slid toward the winding core. As the winding core holding mechanism abuts to the winding core and holds it, the pressing effect on the slider portion is stopped. At that time, the slider portion will not move away from the winding core due to the effect of the locking means; thus, the holding condition of the winding core is maintained. With this, the winding core can be attached by a one-touch operation.

To remove the winding core, the unlocking means is operated to slide the slider portion and the winding core holding mechanism. Thus, the winding core can be removed by an easy operation almost like the one-touch operation.

The invention further provides the roll medium holding device as set forth above, wherein the locking means has wedge-shaped facing planes formed between the slider portion and the guiding portions and a stopper member for locking relative movement between the slider portion and the guiding portions.

Thus, the locking means can be composed of a simple mechanism. Accordingly the cost of the roll medium holding device can be reduced.

The invention still further provides the roll medium holding device as set forth above wherein the operational direction of the unlocking means agrees with the receding direction of the slider portion. Therefore, the operation of the unlocking means and the receding operation of the slider portion can be performed by a one-touch operation. This improves operability.

The invention additionally provides a winding device that winds a thin medium such as paper, film, or cloth output by a printer, comprising the roll medium holding device as described above. With this, the operability is improved for installing an empty winding core in the winding device and for removing the wound-up roll medium from the winding device.

BRIEF DESCRIPTION OF THE INVENTON

In the drawings:

FIG. 1

is a plan view of a center cross-sectional view of a core holding mechanism of the present invention;

FIG. 2

is a dissembled view of the core holding mechanism;

FIG. 3

is a plan view of a center cross-sectional view of the core holding mechanism holding a winding core of larger diameter;

FIG. 4

is a plan view of a center cross-sectional view of the core holding mechanism holding a winding core of smaller diameter;

FIG. 5

is a side view of an entire printer in which a winding device of the present invention is used;

FIG. 6

is a front view of the entire printer in which the winding device is used;

FIG. 7

is a plan view of the winding device;

FIG. 8

is a side view of the winding device when a looseness-detecting sensor is at the detecting position;

FIG. 9

is a side view of the winding device when the looseness-detecting sensor is at the receding position;

FIG. 10

is a front view of the winding device when the looseness-detecting sensor is at the detecting position;

FIG. 11

is a plan view of the winding device when the looseness-detecting sensor is at the detecting position;

FIG. 12

is a front view of a major portion of a sensor arm assembly;

FIG. 13

is a side view of another embodiment of the contact lever;

FIG. 14

is a plan view of a roll medium holding device;

FIG. 15

is a plan view of a major portion of the roll medium holding device;

FIG. 16

is a side view of a guiding portion;

FIG. 17

is a perspective view of the major portion of the roll medium holding device;

FIG. 18

is a perspective view of a locking means;

FIG. 19

is a dissembled view of an unlocking means;

FIG. 20

is a plan view of the locking means at work;

FIG. 21

is a plan view of the condition under which the locking means is unlocked;

FIG. 22

is a plan view of an obliquely wound medium;

FIG. 23

is a side view of the condition under which the medium is wound correctly;

FIG. 24

is a side view of the condition under which the medium wanders off and runs over a flange;

FIG. 25

is a plan view of roller units;

FIG. 26

is a side view of a conventional winding device;

FIG. 27

is a front view of the conventional winding device;

FIG. 28

is a side view of a conventional winding core holding member;

FIG. 29

is a side view of another conventional winding core holding member; and

FIG. 30

is a front view of a position fixing means of the conventional winding core holding member.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The configuration of the present invention is described in detail based on an embodiment illustrated in the drawings.

FIGS. 1 through 25

illustrate an embodiment in which a winding device

1

having winding core holding mechanisms

8

and

32

and a roll medium holding device

33

of the present invention is used in a printer

2

. The printer

2

is a large-scale full color printer

2

of ink jet type or electrostatic recording type, and a drawing medium

3

thereof is, for example, a roll paper wound on a pipe-like paper tube made of cardboard as the winding core

4

.

As illustrated in

FIGS. 1 through 4

, at least one of the winding core holding mechanisms

8

,

32

, which hold the winding core

4

from the right and left sides, has a base

57

, a larger diameter reference portion

58

, a tapered larger diameter centering portion

59

, a smaller diameter reference portion

60

, and a tapered smaller diameter centering portion

61

. The base

57

is fixed in the axial direction of the winding core

4

. The larger diameter reference portion

58

is capable of axially moving in and out of the base

57

and makes contact with an end face

4

a

of a winding core

4

′ of larger diameter. The centering portion

59

is capable of axially moving in and out of the larger diameter reference portion

58

and fits to the core

4

′ of larger diameter. The smaller diameter reference portion

60

is capable of axially moving in and out of the base

57

and makes contact with an end face

4

b

of a winding core

4

″ of smaller diameter. The smaller diameter centering portion

61

is capable of axially moving in and out of the smaller diameter reference portion

60

and fits to the core

4

″ of smaller diameter.

To hold the larger diameter core

4

′, the larger diameter centering portion

59

centers the core

4

′ as falling into the larger diameter reference portion

58

which in turn falls into the base

57

. The end face

4

a

of the larger diameter core

4

′ is positioned at a predetermined reference position

62

with respect to the base

57

. To hold the smaller diameter core

4

′, the smaller diameter centering portion

61

centers the core

4

′ as falling into the smaller diameter reference portion

60

. Then, the smaller diameter reference portion

60

, larger diameter reference portion

58

, and larger diameter centering portion

59

fall into the base

57

, to position the end face

4

b

of the smaller diameter core

4

′ at the reference position

62

.

For this reason, both the larger diameter core

4

′ of 3 inches of inner diameter and the smaller diameter core

4

′ of 2 inches of inner diameter can be held. Thus, two kinds of winding cores

4

′ and

4

″ can be supported without changing components. This improves operability and eliminates a complicated management of components. Also, the reference position

62

for the core

4

can be determined regardless of the size of the mounted core

4

. Therefore, when the core holding mechanism is used in the winding device

1

or in the printer

2

, the reference edge

31

of the medium

3

output from the printer

2

can be easily aligned with the reference position

62

of the winding core

4

. Consequently the oblique winding of the medium

3

, which is normally caused due to disagreement between the reference edge

31

and reference position

62

, can be prevented. Further, each reference portion

58

,

60

supports the winding core

4

by the end face

4

a

,

4

b

, and each centering portion

59

,

61

centers the winding core

4

with the tapered surface. Therefore, even when the inner diameter of the winding core

4

is not uniform, the center of rotation is first centered, and then the end faces

4

a

and

4

b

of the core

4

can be always positioned at the reference position.

In the printer

2

of this embodiment, a right side edge

31

of the output medium

3

in

FIG. 6

is used as a reference edge

31

. The end of the winding core

4

, which is held by the winding core holding mechanism of the winding device

1

on the right side (hereinafter denoted as a fixed-side winding core holding mechanism), is aligned with the reference edge

31

. On the other hand, the core holding mechanism

32

on the left side in

FIG. 6

(hereinafter denoted as a sliding-side core holding mechanism) is supported capable of sliding by a roll medium holding device

33

. The sliding-side core holding mechanism

32

is slid for attaching/detaching the winding core

4

.

In this embodiment, the winding core holding mechanisms

8

and

32

on left and right are configured the same except that the gear portion

15

is provided only in the core holding mechanism

8

and bearing

65

and washer

64

are provided only in the core holding mechanism

32

. As a result, the core holding mechanisms

8

and

32

on the left and right sides share most of the components, and thus the cost of the components can be reduced. Although both the core holding mechanisms

8

and

32

on the left and right sides are used to determine the reference position

62

in this embodiment, if at least fixed-side winding core holding mechanism

8

can determine the reference position

62

, the position

62

can be aligned with the reference edge

31

of the medium

3

. In this case, the sliding-side winding core holding mechanism

32

is simply configured to have a tapered centering portion as illustrated in

FIG. 29

, for example. This simplifies the configuration of the sliding-side core holding mechanism

32

.

Each of the core holding mechanisms

8

and

32

of this embodiment further has a flange shaft

63

fixed to the supporting stay

42

or spool supporting plate

12

. The flange shaft

63

passes through the washer

64

, bearing

65

, base

57

, larger diameter reference portion

58

, larger spring

66

, smaller spring

67

, larger diameter centering portion

59

, smaller diameter reference portion

60

, and smaller diameter centering portion

61

in this order; the smaller diameter centering portion

61

is stopped from coming off by E-ring

68

. The members other than the washer

64

and an inner ring of the bearing

65

rotate together with the core

4

held thereby. Since the bearing

65

is used in each of the core holding mechanisms

8

and

32

, the rotation load on the members rotating together with the core

4

is reduced, and the core

4

held by those members is prevented from idle rotation.

The base

57

is formed with a flange

69

for protecting the side edges of the medium

3

. The base

57

also has protrusion raising portions

70

, axially extending escape grooves

71

cut adjacent to the protrusion raising portions

70

, recess portions

72

, and axially parallel guide grooves

73

. The larger diameter reference portion

58

includes protrusions

74

, which hit against the protrusion raising portions

70

of the base

57

or are guided to the escape grooves

71

, nails

75

to be caught at the recess portions

72

of the base

57

, and cam grooves

76

. Although the larger diameter reference portion

58

is capable of sliding with respect to the base

57

, the nails

75

on the larger diameter reference portion

58

are caught by the recess portions

72

of the base

57

to prevent the reference portion

58

from coming off from the base

57

. The amount of the sliding of the larger diameter reference portion

58

in the direction to fall into the base

57

varies depending on the rotational angle of the larger diameter reference portion

58

with respect to the base

57

. In other words, when the protrusions

74

on the larger diameter reference portion

58

contact the protrusion raising portions

70

, the reference portion

58

can fall into the base no farther than that. On the other hand, when the larger diameter reference portion

58

is rotated and the protrusions

74

are guided to the escape grooves

71

of the base

57

, the reference portion can further fall into the base. Note that, as understood in

FIG. 19

, the protrusion raising portion

70

, escape groove

71

, recess portion

72

, guide groove

73

, protrusion

74

, pawl(nail)

75

, cam groove

76

, cam protrusion

77

, sliding protrusion

78

, and bottom portion

83

are respectively formed at three positions, i.e., equally positioned by 120° around the corresponding circumferences in this embodiment. It is not limited to this.

The protrusion raising portions

70

and protrusions

74

are positioned such that when the winding core

4

′ of larger diameter is made to contact with and pushed into the larger diameter reference portion

58

, the end face

4

a

of the core

4

′ is positioned a predetermined distance (7 mm, for example) away from the inner surface of the flange

69

, as illustrated in FIG.

3

. Consequently the flange

69

is separated from the winding core

4

′ by a predetermined distance, and the end face

4

a

of the core

4

′ can be positioned at the reference position

62

. Further, because the flange

69

and core

4

′ are positioned with a predetermined distance from one another, the gap can be a relief for various situations such as the case that the medium

3

reference edge

31

and the reference position

62

are shifted from one another, the case that the medium

3

absorbs moisture during printing and the width dimension thereof expands, the case that there is a discrepancy between the length of the winding core on the supply side and that on the winding side although the normal dimensions are the same, and the case that there is a discrepancy between the length of the winding core on the supply side and the width of the medium

3

. This provides a countermeasure to the cause that hinders winding. In this embodiment, although the distance between the flange

69

and winding core

4

′ is set 7 mm, it is not limited to this.

The smaller diameter reference portion

60

is formed integrally with the larger diameter centering portion

59

. The smaller diameter reference portion

60

includes cam protrusions

77

, slide protrusions

78

, axially parallel guiding grooves

79

, and engaging holes

80

. The cam protrusions

77

are guided to the cam grooves

76

cut in the larger diameter reference portion

58

, and the slide protrusions

78

are guided to the guiding grooves

73

cut in the base

57

. With this configuration, the smaller diameter reference portion

60

is rotated by the cam mechanism

76

and

77

while sliding into the larger diameter reference portion

58

. Further, the slide protrusions

78

on the smaller diameter reference portion

60

are engaged with and guided into the guide grooves

73

in the base

57

. With this, the smaller diameter reference portion

60

is movable in the axial direction of the base

57

, but locked in the rotational direction to rotate together with the base

57

.

The shape of the cam grooves

76

and the positions of the cam protrusions

77

are configured such that when the winding core

4

′ of smaller diameter is made to contact with and pushed into the smaller diameter reference portion

60

, the cam protrusions

77

guide the cam grooves

76

in the rotational direction to rotate the larger diameter reference portion

58

, and the protrusions

74

on the larger diameter reference portion

58

come off the protrusion raising portions

70

and fall into the escape grooves

71

, as illustrated in FIG.

4

. Then, a bottom portion

81

of the larger diameter reference portion

58

is pushed in by the larger diameter centering portion

59

so that the larger diameter reference portion

58

and larger diameter centering portion

59

fall into the base

57

and recede from the periphery of the winding core

4

″. At the same time, the reference position

62

is determined such that a bottom portion

82

of the smaller diameter reference portion

60

comes into contact with the bottom portion

83

of the base

57

and the end face

4

b

of the winding core

4

″ is positioned a predetermined distance (for example, 7 mm) away from the inner surface of the flange

69

. This also provides a countermeasure to the cause that hinders winding in the same manner as supporting the larger diameter core

4

′. Although the gap between the flange

69

and winding core

4

″ is set 7 mm in this embodiment, it is not limited to this.

The smaller diameter centering portion

61

includes slide protrusions

84

, which are guided into the guiding grooves

79

in the smaller diameter reference portion

60

, and nails

85

which are caught by the edges of the engaging holes

80

in the smaller diameter reference portion

60

. Therefore, the slide protrusions

84

on the smaller diameter centering portion

61

are engaged with the guiding grooves

79

in the smaller diameter reference portion

60

and guided thereto. Accordingly the smaller diameter centering portion

61

is movable in the axial direction of the smaller diameter reference portion

60

, but is locked in the rotational direction to rotate together with the reference portion

60

. Also, the pawls(nails)

85

of the smaller diameter centering portion

61

are caught in the engaging holes

80

to prevent the smaller diameter centering portion

61

and reference portion

60

from separating from each other.

The larger spring

66

is arranged as compressed to push open between the base

57

and smaller diameter reference portion

60

. The smaller spring

67

is arranged as compressed to push open between the base

57

and smaller diameter centering portion

61

.

When the winding core

4

′ of larger diameter is held by the winding core holding mechanism

8

, the device is operated in the following manner. The end portion of the core

4

′ contacts the larger diameter centering portion

59

as illustrated in

FIG. 3

, and the core

4

′ is pushed in against the spring force of the larger spring

66

until the end face

4

a

thereof hits against the larger diameter reference portion

58

. Then, the protrusions

74

on the larger diameter reference portion

58

come into contact with the protrusion raising portions

70

of the base

57

, and the end face

4

a

of the core

4

′ is positioned at the reference position

62

. When the corner portion of the inner diameter surface of the core

4

′ pushes the larger diameter centering portion

59

in, a centering is performed by the tapered surface. Moreover, since the spring force of the larger spring

66

is exerted, a sufficient rotational friction resistance can be provided to the rotational torque necessary for winding. To increase the rotational friction resistance necessary for holding the winding core

4

, a plurality of narrow grooves may be cut along the axial direction on the outer circumference of the larger diameter centering portion

59

.

When the winding core

4

′ of smaller diameter is held by the winding core holding mechanism

8

, the device is operated in the following manner. The end portion of the core

4

″ contacts the smaller diameter centering portion

61

as illustrated in

FIG. 4

, and the core

4

″ is pushed in against the spring force of the smaller spring

67

until the end face

4

b

thereof hits against the smaller diameter reference portion

60

. As the smaller diameter reference portion

60

is pushed in against the spring force of the larger spring

66

, the cam protrusions

77

on the smaller diameter reference portion

60

come into contact with the cam grooves

76

cut in the larger diameter reference portion

58

and the larger reference portion

58

is rotated according to the inclination of the cam grooves

78

. With the rotation of the larger diameter reference portion

58

, the protrusions

74

on the larger diameter reference portion

58

come off the protrusion raising portions

70

of the base

57

and becomes movable deeper along the escape groove

71

. As the winding core

4

′ is further pushed, the bottom portion

82

of the smaller diameter reference portion

60

hits against the bottom portion

83

of the base

57

. This stops the pushing of the winding core

4

″.

When the core

4

″ is pushed in, the corner portion at the inner diameter surface of the core

4

″ contacts the tapered surface of the smaller diameter centering portion

61

to be centered. In addition, since the spring force of both springs

66

and

67

are exerted on the core

4

″, a sufficient rotational friction resistance can be given to the rotational torque necessary for winding. To increase the rotational friction resistance necessary for holding the core

4

, a plurality of narrow grooves may be axially cut in the outer circumference of the smaller diameter centering portion

61

, as illustrated in FIG.

2

.

As the winding core

4

″ is removed and the pressing is stopped, the smaller centering portion

61

and smaller reference portion

60

are returned to the original positions as illustrated in

FIG. 1

by the spring forces of springs

66

and

67

. When the smaller reference portion

61

is pushed back, the cam protrusions

77

on the smaller reference portion

60

push up the inclined surfaces of the cam grooves

76

in the larger reference portion

58

. Then, when the bottom surfaces of the protrusions

74

on the larger reference portion

58

are moved as low as the protrusion raising portions

70

, the cam protrusions

77

rotate the larger reference portion

58

using the cam grooves

76

. In the above manner, the device returns to the normal condition.

The winding device

1

having the above mentioned winding core holding mechanisms

8

and

32

and a roll medium holding device

33

, which will be described later, is now described. As illustrated in

FIGS. 5 through 7

, the winding device

1

comprises a winding mechanism

5

and a looseness-detecting sensor

6

. The winding mechanism

5

winds the medium

4

output by the printer

2

on the winding core

4

. The looseness-detecting sensor

6

detects looseness of the medium

3

and actuates the winding mechanism

5

upon detection. The looseness-sensor

6

is also capable of receding from the moving area of the medium

3

when the sheet tray

7

is attached to the printer

2

. For this reason, even when the sheet tray

7

is attached to the printer

2

for stocking up the cut medium

3

, the medium

3

is prevented from interrupting the looseness-detecting sensor

6

. There is no need to detach/attach a whole or part of the winding device

1

even when the sheet tray

7

is attached/detached.

Used as the winding core

4

is a paper tube made of cardboard, which is the same kind as that used for a blank medium

3

to be set in the printer. The winding core

4

is not limited to such a paper tube, but it is understood that the core may be a tube exclusively used for this purpose.

In this embodiment, the looseness-detecting sensor

6

is attached to the winding mechanism

5

by a sensor arm assembly

10

, as illustrated in

FIGS. 8 through 12

. The winding mechanism

5

has a pair of winding core holding mechanisms

8

and

32

that support the winding core

4

by holding both ends of the core

4

, a motor mechanism

9

that drives at least one of the winding core holding mechanisms

8

,

32

(for example, the winding core holding mechanism

8

on the right side in

FIG. 2

here) as the looseness-detecting sensor

6

detects looseness of the medium

3

, and spool supporting board

12

and spool reinforcing board

13

that support and fix the winding core holding mechanism

8

, motor mechanism

9

, and sensor arm assembly

10

on the stay

11

of the printer

2

.

The motor mechanism

9

has a built-in decelerating gear train. A gear portion

15

is formed around an outer periphery of a boss portion

14

of the winding core holding mechanism

8

. A pinion

16

of the motor mechanism

9

is meshed with the gear portion

15

of the winding core holding mechanism

8

. Note that a code

17

in

FIGS. 8 and 10

indicates a cover.

The sensor arm assembly

10

includes a sensor arm

18

that supports the looseness-detecting sensor

6

to be capable of swinging, an arm rotary shaft

19

that rotatably supports the sensor arm

18

with respect to the winding mechanism

5

and rotates together with the sensor arm

18

, a friction plate

20

united with the sensor arm

18

and arm rotary shaft

19

, a clutch gear

21

that meshes with the gear portion

15

of the winding core holding mechanism

8

and is in contact with the friction plate

20

, a spring

22

composed of a compressed coil spring that presses the clutch gear

21

onto the friction plate

20

, and a spring basket

23

that supports one end of the spring

22

, the other end of which faces the clutch gear

21

.

The arm rotary shaft

19

passes through a substantially U-shaped supporting portion

24

formed at the upper end of the sensor arm

18

and both ends thereof are fixed by E-rings

25

. When the arm rotary shaft

19

is inserted into a supporting portion

24

of the sensor arm

18

, the friction plate

20

, clutch gear

21

, spring

22

, spring basket

23

, and spacer

26

are installed inside the supporting portion

24

in this order. When the spring

22

is installed, it is compressed. The clutch gear

21

is pressed by the force exerted by the spring

22

onto the friction plate

20

. The arm rotary shaft

19

and friction plate

20

are secured to the sensor arm

18

with a D-cut fitting, etc. so that they rotate together with the sensor arm

18

as a single unit. In this embodiment, the arm rotary shaft

19

is formed like a tube. A cord

27

from the looseness-detecting sensor

6

passes through the inside of the arm rotary shaft

19

.

One end of the arm rotary shaft

19

projecting from the sensor arm assembly

10

is rotatably fitted into a hole in the spool supporting plate

12

via the spacer

26

. The other end of the arm rotary shaft

19

projecting from the sensor arm assembly

10

is rotatably fitted into a hole in the spool reinforcing board

13

via the spacer

26

. Then, the spool reinforcing plate

13

is screwed onto the spool supporting board

12

to sandwich the sensor arm assembly

10

.

The sensor arm assembly

10

is rotatable about the arm rotary shaft

19

with respect to the spool reinforcing board

13

and spool supporting board

12

. At that time, the arm rotary shaft

19

, sensor arm

18

, and friction plate

20

rotate together as a single unit within a limited range that will be described later.

The looseness-detecting sensor

6

is a mechanical contact-type sensor that performs detection with the contact of the medium

3

and is united with the winding mechanism

5

. Since the sensor is of a contact-type, the detection is kept accurate, while it may be degraded with an optical sensor because the optical axis of the sensor is intercepted due to contamination or shifted after installation. Thus, reliability of detection can be improved. Because the looseness-detecting sensor

6

is united with the winding mechanism

5

, there is no need to wire the sensor with the winding mechanism

5

, which is normally required when the optical sensor is used in the printer

2

. This simplifies the operation of installing the sensor in the printer

2

.

The looseness-detecting sensor

6

has a contact lever

28

, which is attached to the bottom portion of the sensor arm

18

to be capable of swinging, and a photo sensor

29

for detecting the swing of the contact lever

28

. The contact lever

28

is swung by the contact of the medium

3

, and this movement is detected by the photo sensor

29

. The contact lever

28

is capable of swinging with a very small force. In other words, the contact lever

28

is normally in a raised position (shown by a solid line in FIG.

8

), and the weight thereof is well-balanced so that the sensor

6

swings down to a lower position (shown by the double-dotted line in the same figure) with a very small force. With this, the lever

28

is protected from bending or damage when the medium

3

comes into contact therewith. Note that the contact portion of the contact lever

28

with the medium

3

can be made in a circular arc shape as shown in

FIGS. 8 and 9

, or a rotatable roller

30

may be attached to the sensor as shown in

FIG. 13

to reduce contact resistance.

As illustrated in

FIGS. 14 through 19

, the roll medium holding device

33

includes a slider portion

34

fixed to the core holding mechanism

32

and a guide portion

35

supporting the slider portion

34

to be capable of sliding along the width direction W of the medium

3

. The roll medium holding device

33

also includes a locking means

36

, which locks the slider portion

34

from sliding in the direction moving away from the winding core

4

, and an unlocking means

37

which can unlock the locking means

36

. The sliding portion

34

is pushed and slid toward the winding core

4

for attaching the winding core

4

. Since the locking means

36

is not operating at that time, the slider portion

34

can be slid easily. After the winding core holding mechanism

32

contacts and holds the winding core

4

, the pushing effect on the slider portion

34

is stopped. At that time, the slider portion

34

never moves in the direction away from the winding core

4

because of the effect of the locking means

36

, maintaining a good holding condition of the winding core

4

. Accordingly the winding core

4

can be installed by a one-touch operation. To remove the winding core

4

, the unlocking means

37

is operated to slide the slider portion

34

and winding core holding mechanism

32

. Accordingly the winding core

4

can be removed by an easy operation almost like a one-touch operation.

The guiding portions

35

are composed of guiding rails extending along the stay

11

formed in the width direction W of the printer

2

from the left end to the vicinity of the right end of the winding device

1

. The guiding portions

35

are channel components, each of which has a substantially U-shaped cross-section; they are arranged at the top and bottom so that the open ends of substantial U-shape face each other. As illustrated in

FIG. 16

, each of the guiding portions

35

is positioned by hitting against a positioning projection

38

which is formed at the stay

11

in the horizontal direction. Each guiding portion

35

is positioned in the above manner, and then held in a guiding rail securing plate

39

and tightly secured to the stay

11

. In this embodiment, the guiding portion is tightly secured by a screw.

The slider portion

34

includes a slide plate

40

, sliding blocks

41

attached at the four comers of the slide plate

40

, and a supporting stay

42

for an operator to perform a sliding operation. The sliding blocks

41

are fitted at the four corners of the slide plate

40

, as illustrated in

FIG. 18

, etc. Contact points

43

are formed on the front F surfaces and back R surfaces of the sliding blocks

41

to make contact with inner surfaces of the guiding portions

35

. Consequently the contact area of the guiding portions

35

with the sliding blocks

41

can be reduced to a minimum to reduce resistance when sliding. One of the four sliding blocks

41

is not formed with the contact points

43

. Therefore, even if the guiding portions

35

are distorted due to errors in dimensions or assembly, the slider portion

34

can be slid easily.

The locking means

36

includes wedge-shaped facing planes

44

provided between the slider portion

34

and guiding portions

35

, and a stopper member

45

that creeps in and widens the space between the facing planes

44

to lock relative movement of the slider portion

34

and guiding portions

35

. Consequently the locking means

36

can be configured with a simple mechanism, thus reducing the cost for the roll medium holding device

33

. In this embodiment, as illustrated in

FIGS. 20 and 21

, the facing planes

44

consist of an inclined surface

46

constructed inside the guiding portion

35

of the slide plate

40

and an inner surface

47

of the guiding portion

35

that is opposed to the inclined surface

46

.

The stopper member

45

is composed of a metallic cylindrical roller, for example. Also, a spring

48

composed of a compressed coil spring is provided between the sliding block

41

and the stopper member

45

to push the stopper member

45

into the space between the facing planes

44

. The spring

48

is supported by a spring supporting projection

49

on the sliding block

41

. Although the stopper member

45

is composed of a cylindrical roller in this embodiment, it may be formed in a spherical shape or a wedge shape. With either shape, the stopper member

45

moves into the space between the facing planes

44

to lock relative movement between the slider portion

34

and the guiding portions

35

.

The core

4

is installed in the following manner. As the slider portion

34

is pushed toward the core

4

, the stopper member

45

escapes from the space between the facing planes

44

. Therefore, the slide plate

40

is not locked and can be slid easily. As the sliding-side winding core holding mechanism

32

abuts to the core

4

and holds it, the pressing of the slider portion

34

is stopped. Since the spring

48

has pushed the stopper member

45

into the space between the facing planes

44

, even when the operator's hand is released or the slider portion

34

is pushed in the direction away from the core

4

as illustrated in

FIG. 20

, the stopper member

45

moves to creep in the space between the facing planes

44

. Consequently the sliding plate

40

is locked onto the guiding portions

35

. Thus, both ends of the core

4

are held by the winding core holding mechanisms

8

and

32

on the left and right sides, which maintains the holding condition.

The unlocking means

37

includes operation lever

50

and unlocking lever

51

which are attached to the supporting stay

42

to be capable of swinging, as illustrated in FIG.

19

. The operation lever

50

is supported at the portion of the supporting stay

42

on the sliding plate

40

side, i.e., on the rear side R by a rotary shaft

52

, and also has an operating portion

53

projecting to the front side F. The unlocking lever

51

is supported at the center of the supporting stay

42

by a rotary shaft

54

, and has a pressing portion

55

that presses the stopper member

45

in the direction to move off the space between the facing planes

44

by the swing thereof. The operation lever

50

is formed with a lever pushing protrusion

56

that swings the unlocking lever

51

when the lever

50

is rotated about the rotary shaft

52

. As illustrated in

FIG. 15

, as the operating portion

53

of the operation lever

50

is pushed in the arrow direction, the operation lever

50

is swung, and the lever pushing protrusion

56

swings the unlocking lever

51

. Then, as illustrated in

FIG. 21

, as the pressing portion

55

moves the stopper member

45

out of the space between the facing planes

44

, the slider portion

34

is unlocked.

In this embodiment, as the operation lever

50

is moved in the direction to which the slider portion

34

recedes (in the arrow direction in FIG.

15

), the unlocking lever

51

moves the stopper member

45

out of the space between the facing planes

44

. In other words, the operation direction of the unlocking means

37

is same as the direction in which the guiding portion

35

is receded. For this reason, the unlocking means

37

is operated simultaneously with the receding operation of the slider portion

34

by a one-touch button operation. This improves operability.

Also, the unlocking means

37

is equipped with the operation lever

50

and unlocking lever

51

and the swing of the operation portion

53

swings the pressing portion

55

with the effect of a lever. For this reason, even when the stopper member

45

is tightly stuck between the facing planes

44

, it can be moved with a small force.

In this winding device

1

, as illustrated in

FIG. 22

, a roller unit

86

is provided in the vicinity of each end of the core

4

to press the medium

3

tight while it is wound and to prevent the medium

3

from being wound crooked. Each of the roller units

86

consists of a primary roller

87

and a secondary roller

88

. The primary roller

87

contacts the medium

3

during the winding of the medium

3

to give resistance (pressure) to the medium

3

. The secondary roller

88

contacts the medium

3

individually or together with the primary roller

87

when the medium

3

is wounded obliquely and runs over the core holding mechanisms

8

and

32

, so that a larger resistance than that only by the primary roller

87

is given. When the medium

3

is wound straight as shown by the single-dotted line in

FIG. 22

, the medium

3

is given resistance only by the primary roller

87

in each roller unit

86

as illustrated in

FIG. 23

, and thus the same resistance is given to both right and left sides of the medium

3

. Consequently the medium

3

is lightly pressed and wound up, so that even a medium

3

that cannot tear easily can be tightly wound up.

When the medium

3

wanders off and one side edge thereof runs over one of the core holding mechanisms (here, the sliding-side core holding mechanism

32

) as shown by the double-dotted line in

FIG. 22

, the resistance is given to the medium

3

by the secondary roller

88

only or together with the primary roller

87

in the roller unit

86

close to the core holding mechanism

32

, over which the medium

3

has run, as illustrated in FIG.

24

. On the other hand, the other roller unit

86

on the other end is given a resistance only by the primary

87

because the medium

3

does not expand. For this reason, the winding continues as the expanding side of the medium

3

is given a large resistance while the non-expanding side of the medium

3

is given a small resistance. As a result, the medium

3

is corrected from the oblique winding direction, to the opposite direction of wandering-off. Thus the direction of the oblique winding of the medium

3

is changed to correct the winding direction.

In addition to the primary and secondary rollers

87

and

88

, each roller unit

86

further includes a bracket

90

, which is mounted capable of swinging up and down with respect to the stay

11

with the work of a hinge

89

and supports the primary and secondary rollers

87

and

88

. The bracket

90

switches the contact conditions of the rollers from one under which at least one of the rollers

87

,

88

contacts the medium

3

to the other under which none of the rollers

87

,

88

contact the medium

3

as the bracket

90

is lifted to the back.

As illustrated in

FIG. 25

, each of the rollers

87

and

88

consists of a support shaft

91

which is fixed to the bracket

90

to be incapable of rotating and extends along the width direction W, a rubber roller

92

, a torque limiter

93

, a one-way clutch spring

94

, and a spacer

95

which is mounted onto the support shaft

91

in this order. The torque limiter

93

is of a double-layered cylindrical shape and the outer portion thereof is capable of rotating in one direction around the inner portion with a certain force, but is incapable of rotating in the opposite direction. A publicly-known torque limiter can be used. The outer portion of the torque limtter

93

is engaged with the rubber roller

92

to rotate together with the roller

92

.

The one-way clutch spring

92

is provided between the inner portion of the torque limiter

93

and the support shaft

91

. As rotated in the winding-up direction (shown by arrow in FIG.

25

), the one-way clutch spring

94

is wound up tightly and united with the support shaft

91

. With this, when the rubber roller

92

rolls touching the medium

3

in the winding direction, the rubber roller

92

and the outer portion of the torque limiter

93

rotate, but the inner portion of the torque limiter

93

does not rotate because the inner portion is fixed to the support shaft

91

by the one-way clutch spring

94

. For this reason, a force is exerted as a brake by the torque limiter

93

. The strength of the brake force depends on the torque value of the limiter

93

.

When the rubber roller

92

is rotated in the direction opposite to the winding direction to pull out the wound-up medium

3

, the outer portion and inner portion of the torque limiter

93

are rotated together; since this pulling-out direction is the same direction to which the one-way clutch spring

94

winds and spreads, the outer and inner portions of the limiter

93

rotate around the supporting shaft

91

. Consequently the rubber roller

92

, torque limiter

93

, and one-way clutch spring

94

rotate altogether around the support shaft

91

. In other words, the torque limiter

93

does not generate the braking force.

As illustrated in

FIGS. 23 and 24

, two of rollers

87

and

88

are arranged with a difference in level. Because of this, when the medium

3

is wound without touching the flange

69

, only the primary roller

87

contacts the medium

3

as illustrated in

FIG. 23

; when the medium

3

runs over the flange

69

, only the secondary roller

88

contacts the medium

3

as illustrated in FIG.

24

.

The operation of the above mentioned winding device

1

to wind the medium

3

on the core

4

will be described hereinafter.

To wind the medium

3

on the core

4

continually, the sheet tray

7

is not attached. The core

4

is mounted to the roll medium holding device

44

. At that time, an end portion of the core

4

is first attached to the fixed-side core holding mechanism

8

, then the sliding-side core holding mechanism

32

is slid until it hits against the end faces

4

a

and

4

b

of the core

4

, and finally the core

4

is sandwiched between the core holding mechanisms

8

and

32

. Thus, the core

4

is kept held unless the operation lever is operated. Because the core

4

is held by the core holding mechanisms

8

and

32

, the alignment of the end faces

4

a

and

4

b

of the core

4

with the reference position can be automatically performed no matter which size the core is.

After the core

4

is mounted, the output by the printer

2

is started. As the front end of the medium

3

reaches the core

4

with extra length, it is attached to the core

4

with a scotch-type tape. Even after this, the printer

2

continues output.

As the printer

2

continues printing out the medium

3

, the medium

3

becomes very loose. The detecting sensor

6

detects the looseness of the medium

3

. With this, the driving portion

9

is actuated so that both core holding mechanisms

8

and

32

and the core

4

are rotated together to start winding the medium

3

. While the medium

3

is being wound, the printer

2

still keeps printing out the medium

3

. However, since the speed of winding the medium

3

is faster than the output speed of the printer

2

, the looseness of the medium

3

decreases, and finally the detecting sensor

6

no longer detects the looseness. At this point, the operation of the driving portion

9

is stopped to stop winding the medium

3

.

As the medium

3

becomes very loose, it is wound up; as the medium

3

is tensioned, the operation of winding-up is stopped. By repeating these operations, the medium

3

output by the printer

2

can be wound on the core

4

of the winding device

1

. When wound, the medium

3

is pressed by the first rollers

87

on the left and right sides, resulting in a tight winding.

The medium

3

may wander off during winding, as shown by the double-dotted line in

FIG. 22

, due to a slightly crooked end portion of the medium

3

when attached with a scotch-type tape. If this happens, the side edge of the medium

3

comes into contact with the flange

69

and it traces a spread course as illustrated in FIG.

24

. As the medium

3

becomes loose around the core

4

, the secondary roller

88

comes into contact with the medium

3

. At the same time, since the medium

3

goes away from the flange

69

on the other side, the winding on that side does not increase and the primary roller

87

is in contact with the medium

3

.

For this reason, the brake forces are generated in different levels at the roller units

86

on the right and left sides. As the roller units keep generating brake forces of different levels, the right side of the medium

3

, which is given a weaker brake force, has less pressure on winding than the left side of the medium

3

which is given a stronger brake force. Consequently the winding length of the medium is longer on the right side. Because of the difference in the winding lengths on the right and left sides of the medium

3

, the oblique winding is eased or the direction of the oblique winding is turned over (corrected). Thus, the oblique winding can be prevented.

To remove the wound-up medium

3

from the winding device

1

, the sliding-side core holding mechanism

32

of the winding device

1

is receded to the side. For this, while the operation lever

50

is being pushed toward the receding direction, the slider portion

34

is easily slid. Then, the heavy roll medium

3

can be dismounted easily and safely.

When the medium

3

output by the printer

2

is cut, the sheet tray

7

is attached and the looseness-detecting sensor

6

at the detecting position shown by a broken line in

FIGS. 8 and 5

is receded to the back.

The above is operated in the following manner. First, the sensor arm

18

is pushed to the back by a finger and the like. Then, the sensor arm

18

is rotated to rotate the friction plate

20

. At that time, the friction plate

20

functions to rotate the clutch gear

21

. But, since the clutch gear

21

is meshed with the gear portion

15

of the fixed-side core holding mechanism

8

, it does not rotate. For this reason, the friction plate

20

slips against the clutch gear

21

. As a result, the entire sensor arm assembly

10

is rotated, and the looseness-detecting sensor

6

is caused to recede to the back. Otherwise, the fixed-side core holding mechanism

32

may be held by hand and turned to the opposite direction to the winding direction to cause the looseness-detecting sensor

6

to recede to the back in the same manner.

A portion of the sensor arm

18

abuts to the spool supporting plate

12

or spool reinforcing plate

13

and reaches the receding position as illustrated by the double-dotted line in

FIGS. 9 and 5

. Even under the condition in which the sensor arm assembly

10

is caused to recede furthest to the back, since the friction plate

20

and clutch gear

21

feel the friction resistance due to the force of the spring

22

, they do not move from the positions thereof. The clutch gear

21

is engaged with a decelerating gear train of the motor mechanism

9

via the gear portion

15

of the fixed-side core holding mechanism

8

and the pinion

16

of the motor mechanism

9

; therefore, the sensor arm assembly

10

never turns with the weight thereof. Consequently the sensor arm assembly

10

is held at the position where it was stopped by the friction resistance thereof with the friction plate

20

.

For causing the looseness-detecting sensor

6

to recede to the back, the operation is not limited to the above manual operation, but the power of the motor mechanism

9

may be used. In this case, the motor mechanism

9

is driven to rotate the fixed-side core holding mechanism

8

in the opposite direction to the winding direction. With this, the clutch gear

21

is rotated counterclockwise in FIG.

4

. Then, the friction plate

20

is exerted against the friction resistance counterclockwise by the clutch gear

21

, and the entire sensor arm assembly

10

united with the friction plate

20

rotates and recedes to the back. It is understood that, even with this, the receded condition can be maintained.

When cutting, the output medium

3

is stopped to start winding with the winding device

1

again, the sheet tray

7

is removed and the looseness-detecting sensor

6

is pulled forward to the looseness-detecting position.

The above operation is performed in the following manner. First, the core

4

is set in the winding device

5

. The front edge of the medium

3

output by the printer

2

is attached to the core

4

with a scotch-type tape. By manual operation or turning on a fast forward switch, the core holding mechanism

8

is rotated in the winding direction to wind the medium

3

on the core

4

by more than single turn. Then, the preparation for winding the medium is completed. In other words, by rotating the fixed-side core holding mechanism

8

, the clutch gear

21

engaged with the gear portion

15

of the core holding mechanism

8

is rotated clockwise in FIG.

5

. Then, the friction plate

20

is exerted the clockwise rubbing resistance by the clutch gear

21

, and the entire sensor arm assembly

10

united with the friction plate

20

rotates to return to the front side in the looseness-detecting position. Also, a portion of the sensor arm

18

abuts the spool supporting plate

12

or spool reinforcing plate

13

so that the sensor arm assembly

10

is positioned at the looseness-detecting position. Thus, the looseness-detecting sensor

6

automatically returns to the detecting position upon the movement of winding the medium

3

. The looseness-detecting sensor

6

always and for certain returns to the detecting position.

When the core holding mechanism

8

starts winding, the gear portion

15

of the fixed-side core holding mechanism

8

continually attempts to rotate the clutch gear

21

, but the clutch gear

21

keeps slipping against the friction plate

20

. Because of this, the sensor arm assembly

10

does not move from the looseness-detecting position.

Note that although the above described embodiment is an example of the preferred embodiments, the present invention is not limited to this, but can be modified within the scope of the invention.

For example, although the winding core holding mechanisms

8

and

32

and the roll medium holding device

33

are used in the winding device

1

in this embodiment, they may be mounted onto the medium supplying portion in the printer

2

to hold the blank roll medium

3

before printing. Even in this case, the operability is improved in changing the core

4

to another of different size, and the reference position for the medium

3

to be output can be easily aligned with the winding core holding mechanisms

8

and

32

. Also, the roll medium

3

can be easily attached/detached.

As understood from the above description, according to the winding core holding mechanism described above, both winding cores of larger and smaller diameters can be supported without attachment and detachment thereof. This improves operability and eliminates the troublesome management of the components.

Further, the reference position for the winding core can be always the same position regardless of the size of the attached core. For this reason, when the winding core holding mechanisms are used in a printer or a winding device, the position of the medium output by the printer can be easily aligned with that of the winding core. This prevents an oblique winding of the medium. Also, the winding core having the same width as the medium to be output can be used.

Further, each reference portion supports the winding core by the end face, and each centering portion centers the core with the tapered surface thereof. Therefore, even if the inner diameter of the winding core is not uniform, the center of rotation is first centered, and then the winding core end face is always set at the reference position.

Since there is no need to use a winding core exclusively used for the winding purpose, the cost of the winding core as well as the management of the winding core can be eliminated

According to the invention, the reference edges of the medium supplied by the printer can be easily aligned with the reference position on the winding side. This prevents the oblique winding of the medium.

As understood from the above description, according to one form of the described roll medium holding device, the operation of moving/locking of the winding core holding mechanism and the operation of unlocking/moving can be easily performed by a one-touch operation. This improves safe operability of detaching/attaching the roll medium to a great extent.

According to another form of the roll medium holding device, the locking means can be composed of a simple mechanism. Accordingly the cost of the roll medium holding device can be reduced.

According to yet another form of the roll medium holding mechanism, the operation of the unlocking means and the receding operation of the slider portion can be performed by a one-touch button operation. This further improves operability.

According to the winding device of the invention, the operability is improved for installing an empty winding core in the winding device and for removing the wound-up roll medium from the winding device.

While the foregoing description and drawings represent the present invention, it will be obvious to those skilled in the art that various changes may be made therein without departing from the true spirit and scope of the present invention.

Number	Date	Country	Kind
2000-107191	Apr 2000	JP
2000-107199	Apr 2000	JP

Number	Name	Date	Kind
1119179	Krauth	Dec 1914	A
1811779	Caps	Jun 1931	A
2214097	Anderson	Sep 1940	A
2905404	Simmons	Sep 1959	A
3326487	Huck	Jun 1967	A
4915319	Gerber	Apr 1990	A
5662288	Chiang	Sep 1997	A

Winding core holding mechanism, roll medium holding device having the same, and winding device using said mechanism and device

Information

Patent Number

Date Filed

Date Issued

Inventors

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Agents

CPC

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US

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Abstract

Description

Claims

Priority Claims (2)

US Referenced Citations (7)