JPS6013656Y2 - Ink ribbon tension device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an ink ribbon tensioning device, and more particularly to a tensioning device for an ink ribbon feeding device that includes a drive mechanism that drives one winding gear and winds up the ink ribbon from the other winding gear. be.

Various printers are well known for recording input/output information of office processing machines, calculation results of computers, and other recorded information. The desired characters, numbers, and other symbols are recorded on the recording paper by striking.

As is well known, the ink ribbon is fed and moved each time a printing operation is performed, so that characters with even shading can be obtained.

Some ink ribbon feeding devices include those that have a motor device exclusively for feeding, and those that drive a winding gear using the driving force of a printing mechanism.

The former method has the advantage of providing continuous feeding at high speed, but has the drawbacks of increasing the size of the device and increasing the price.

The latter has the advantage that the feeding device can be provided with a simple structure consisting of the ratchet teeth of the winding gear and the drive pawl, and is suitable as a small-sized ink ribbon feeding device.

All of these conventional feeding devices have the disadvantage that the ink ribbon becomes slack during the feeding operation.

In other words, in a motor feeder, the drive-side winding gear can maintain a constant rotational speed, but the driven-side winding gear cannot follow constant rotation due to changes in frictional force, and as a result, the ink ribbon Sagging occurs.

Further, in an ink ribbon feeding device using ratchet feeding, a winding gear is driven intermittently, and the feeding action is supplied to the winding gear as an impact force by a driving claw.

As a result, the winding gear on the wave winding side has the disadvantage that it slackens every time it is fed.

Slagging of the ink ribbon significantly reduces the quality of printed characters, and for this reason, conventional devices have been provided with a sagging prevention mechanism using a tension roller.

FIG. 1 schematically shows a conventional ratchet type ink ribbon feeding device.

A spool shaft 12.14 is fixedly planted on the base plate 10 of FIG.

A winding gear 16 is rotatably supported on the spool shaft 12, as shown in FIG.

The winding gear 16 connects the flange 18 of the shaft 12 and the base plate 1.
0 and will not come off from the substrate 10.

A winding gear 20 is similarly fixed to the spool shaft 14, and ribbon spools 22 and 24 are mounted and held on both shafts 12 and 14, respectively.

The ribbon spool 22 is provided with two protrusions 26 and 28, and these protrusions 26 and 28 fit into the through hole 3 of the winding gear 16.
0 and 32, respectively, and the ribbon spool 22 is rotated together with the winding gear 16.

An ink ribbon 34 is wound around both ribbon spools 22 and 24 with both ends thereof being rotated.

An ink ribbon 34 is guided by guide rollers 36 and 38 fixedly planted on the substrate 10, and guided between a type drum 40 and a plurality of printer groups 42.

For example, in a flying type printer, the type drum 40 rotates continuously, and when the type provided on the peripheral surface reaches a predetermined position, a hammer 42 of a desired digit is struck toward the type drum 40, and the ink ribbon 34 and the type drum 40 are struck. Desired characters are printed on the recording paper inserted between the two.

The winding gears 16 and 20 have ratchet teeth 16a, 20a on their outer peripheries, and these ratchet teeth 16at
Either one of 20a is intermittently driven by a drive claw 44.

The drive pawl 44 is driven by a well-known printing mechanism (not shown), and impulsively drives the ratchet of the winding gear on the drive side.

Due to this impact feeding, the winding gear on the driven side rotates more than necessary due to its inertia, causing slack in the ink ribbon 34.

In the conventional apparatus, in order to take up slack in the ink ribbon 34, a tension roller 48 fixed to the tip of a tension lever 46 which is pivoted to the substrate 10 is pressed against the ink ribbon 34.

A tension spring 50 is hung between the other end of the tension lever 46 and the substrate 10, and a tension roller 48
is always pressed against the ink ribbon 34.

This slack prevention mechanism is installed near both winding gears.
In FIG. 1, a tension lever 52, a tension roller 54, and a tension spring 56 are shown on the winding gear 16 side.

In this conventional slack prevention mechanism, when the ink ribbon 34 is sent with an impact, the tension roller 48 or 54
This has the drawback that the rotational movement is performed more than necessary, and the slack of the ink ribbon 34 is increased.

The present invention was devised in view of the above-mentioned conventional problems, and its purpose is to improve the tension of the ink ribbon so that the ink ribbon does not become sagging even when the motor feeds or the driving pawl is used for impact feeding. The goal is to provide equipment.

In order to achieve the above object, the present invention includes a first feeding member that rotates integrally with the ribbon spool, and a second feeding member that is rotatably provided with respect to the first feeding member. It is characterized in that a tension spring is provided between the members to eliminate slack that occurs between the two feeding members.

Preferred embodiments of the present invention will be described below based on the drawings.

FIG. 3 shows a cross section of the tensioning device according to the invention, and FIG. 4 shows a perspective view thereof.

A spool shaft 62 is rotatably fixed to the printer board 60, and this spool shaft 62 is fixed by a bearing hole 64 of the board 60 and a bearing hole 72 of a receiving plate 70 fixed to the board 60 with screws 66, 68. Ru.

A disk 74 is fixed to the spool shaft 62, and a ribbon spool 76 is inserted and held onto the disk 74.

A positioning hole 78 provided in the ribbon spool 76 engages with a vertical bend 80 provided in the disk 74, and the ribbon spool 76 rotates together with the spool shaft 62.

The ribbon spool 76 includes an ink ribbon 82 as is well known.
is wound.

A collar 84 is fixed to the spool shaft 62 by a set screw 86.

A feed plate 8 forming a first feed member is provided at one end of the collar 84.
8 is fixed.

It is therefore understood that the first feed member rotates integrally with the ribbon spool 76.

A feed gear 90 forming a second feed member is rotatably fixed to the other end of the collar 84, and its axial movement with respect to the collar 84 is restricted by a C ring 92.

The feed gear 90 meshes with a feed pinion 96 fixed to a drive shaft 94 that is fixed to the base plate 60 and the receiving plate 70, and receives a feed force transmitted to the drive shaft 14 from a known drive mechanism (not shown).

The drive member may comprise a drive pawl and ratchet mechanism as is well known, or may be formed from an intermittent motor feed mechanism.

The drive shaft 94 engages with the drive device only when the ribbon spool 76 is on the driving side, and is disengaged when the ribbon spool 76 is on the driven side.

In the present invention, the feed plate 88 which is the first feed member
A contact member is provided on one of the feed members in order to abut and engage both feed members during relative rotation between the feed gear 90, which is the second feed member, and the contact member in the embodiment is The feed plate 88 is a first feed member, and a feed surface 88a is formed on the outer periphery of the feed plate 88, which is a first feed member, in correspondence with this pin 98.

Therefore, it is understood that the pin 98 can come into contact with the feeding surface 88a during relative rotation of both feeding members.

Of course, in the present invention, the abutment member, for example, a pin, is provided on the first feed member side, that is, the feed plate 88, and the corresponding abutment surface is provided on the second feed member, that is, the feed gear 90.
It is also possible to form it with a long hole provided on the side.

Additionally, a feature of the present invention is that a tension spring is stretched between the first feeding member and the second feeding member and has a tension generation range to absorb the slack that occurs between the two members. In the embodiment, a tension spring 102 is stretched between the feed plate 88 and a pin 100 mounted on the feed gear 90.

The tension spring 102 in the embodiment has one end engaged with a hole in the feed plate 88 and the other end engaged with the aforementioned pin 100 set on the feed gear 90; For example, the stop can also be achieved using a hole provided in the gear 90.

Although the above description has been made regarding one ribbon spool side of the ink ribbon feeding device, a similar feeding device is also provided on the other ribbon spool side.

The tension device according to the present invention has the above configuration, and its operation will be explained next.

When the ribbon spool 76 is used as a drive side, the ink ribbon 82 is wound in the direction of arrow A.

This driving force is transmitted from the drive shaft 94 to the pinion 96 to the feed gear 9.
0 and the ribbon spool 76 via the feed plate 88.

The feed gear 90 and the feed plate 88 have a rotating waist pin 98 in contact with the feed surface 88a of the feed plate 88 in the direction of arrow B.

At this time, the tension spring 102 is in a tensioned state, but this tension is smaller than the feed load applied to the ribbon spool 76, and the pin 98 and the feed surface 88a do not separate.

When the ribbon spool 76 is used as a driven side,
The ink ribbon 82 is sent out in the direction of arrow C.

At this time, the drive shaft 94 is separated from the drive device.

However, a certain amount of load is applied to the feed gear 90 due to meshing resistance between the feed gear 90 and the pinion 96, shaft friction of the drive shaft 94, and the like.

Therefore, when the feed plate 88 is driven in the direction indicated by the arrow, the tension of the tension spring 102 is set to be smaller than this load, so that the feed plate 88 is in contact with the pin 98 and is driven.

If the ribbon spool 76 over-rotates in this state, the ink ribbon 82 will slacken, but this slack will leave the ribbon spool 76 in a free state.

Therefore, the ribbon spool 76 can rotate with the free rotation of the spool shaft 62, and since the rotational friction force at this time is extremely small, the tension stored in the tension spring 102 is applied to the ribbon spool 76 via the feed plate 88. , the ribbon spool 76 is slightly returned, and as a result, the slack of the ink ribbon 82 is absorbed.

The amount of slack generated in the ink ribbon 82 is approximately constant, and the range of tension generation from the state where the tension spring 102 is under tension by the feed plate 88 until the tension is removed is set to be larger than the amount of slack described above.

Therefore, slack in the ink ribbon 82 is always absorbed by the tension spring 102.

In the illustrated embodiment, the spool shaft 62 rotates with the substrate 60, but it is also possible to provide the substrate 60 with a first feeding member that rotates the spool shaft 62 with respect to the fixed spool shaft 62.

Further, the feed gear 90 can be directly driven by a drive pawl or the like, and in this case, by connecting a certain amount of friction force generating means to the feed gear, a load is applied between the first feed member and the second feed member. be able to.

As explained above, according to the present invention, it is possible to reliably prevent slack from occurring in the ribbon spool on the driven side, and it is possible to provide a tension device that is extremely suitable for ink ribbon feeding devices such as printers. Become.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a conventional ink ribbon feeding device, FIG. 2 is a cross-sectional view of the main part of the winding gear shown in FIG. 1, FIG. 3 is a cross-sectional view of the tension device according to the present invention, and FIG. FIG. 4 is a perspective view of the main part of FIG. 3; 76... Ribbon spool, 88... First feeding member, 90... Second feeding member, 94...
...Drive shaft, 102...Tension spring.

Claims (1)

[Claims for Utility Model Registration] A first feeding member that rotates together with the ribbon spool, a second feeding member rotatably provided coaxially with the first feeding member, and a second feeding member that engages with the second feeding member. a drive mechanism that provides driving force for feeding the ink ribbon; and a tension spring that is stretched between the first feeding member and the second feeding member and has a tension generation range for absorbing slack that occurs between the two feeding members. , an abutment member provided on either one of the feeding members for abutting and engaging the first and second feeding members with the tension spring tensioned when the first and second feeding members rotate relative to each other; tension device.