JPS5943320B2 - Roll paper back tension mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a roll paper holding device, and particularly to a roll paper back tension mechanism suitable for applying back tension to the roll paper.

It is known that when a roll of recording paper or the like is passed through, if an appropriate back tension is applied, the recording paper can be passed without shifting to the left or right.

Recently, roll paper back tension mechanisms as shown in FIGS. 1, 2, and 3 have been attempted. below,
This will be explained according to the drawings. Note that FIG. 4 shows the paper passing path of the roll paper, and the roll paper 1 is passed in the direction of the arrow. The roll paper 1 is inserted between a thermal head 3 and a head roller 4 along a paper guide 2, and is then passed through by driving rotation of the head roller 4. The passed roll paper 1 is discharged to the outside along the paper guide 5. In Figure 3, 1
is a roll paper integrated with a pair of roll paper shafts 7 each having a disc 6.

FIG. 3 shows a state in which the shaft portion 10 of the roll paper shaft, that is, the roll paper is set in the U-shaped groove bearing 9 of the roll paper holding plate 8. The roll paper holding plate 8 made of an elastic body fixed to the rear panel 11 has two
It bends inward as shown by the dotted chain line. Further, a rubber brake shoe 12 is fixed to the lower part of the U-shaped groove bearing of the roll paper holding plate 8. When the roll paper holding plate 8 is pushed open outward and the roll paper 1 is set, the disc 6 of the roll paper shaft 7 receives a force that pinches it inward via the brake shoe 12. In this state, when the roll paper 1 is passed through and the roll paper 1 integrated with the roll paper shaft T rotates in the direction of arrow 13, a frictional force acts between the disc 6 and the brake shoe 12, and the roll paper travels in the direction of travel. The roll paper 1 is braked by receiving a force in the opposite direction. That is, the roll paper 1 is subjected to back tension, and the back tension corrects the deviation to the left and right, so that the roll paper 1 continues to advance normally. In the above-mentioned back tension mechanism, when the roll paper 1 is running low, the shaft portion 10 of the roll paper shaft 7 rolls along the inner surface of the U-shaped groove bearing 9, and the roll paper 1 is moved to the open end of the U-shaped groove bearing 9. I had a problem with it falling off.

Furthermore, when setting the roll paper 1 on the roll paper holding plate 8, it is necessary to push the roll paper holding plate 8 outward by hand.
The drawback was that it was difficult to operate. SUMMARY OF THE INVENTION It is an object of the present invention to provide a roll paper back tension mechanism which improves the drawbacks of the prior art and prevents the roll paper from falling off.

Still another object of the present invention is to provide a roll paper back tension mechanism that allows easy replacement of the roll paper.

The present invention provides a roll paper holding device in which back tension is applied to the roll paper by the sliding friction force between the rolled paper core and an elastic body provided on the roll paper shaft, and furthermore, the roll paper shaft does not rotate. As a means for preventing the roll paper from falling off when only the roll paper rotates, a roll paper shaft is provided with an elastic body that contacts the core surface of the roll paper inside the core and generates sliding friction; This is a roll paper back tension mechanism characterized by comprising a bearing that holds the shaft of a roll paper shaft.

An embodiment of the present invention will be described below with reference to the drawings. Fifth
, 6 and 7, reference numeral 8 denotes a pair of L-shaped roll paper holding plates fixed to the rear panel 11 in a suitable manner. A bearing member 15 made of resin is adhesively fixed to a U-shaped groove 14 provided near the tip of the roll paper holding plate 8 and having an open upper part. In FIG. 5, reference numeral 1 denotes a roll-shaped recording paper for outer winding (hereinafter referred to as roll paper) wound around a core 16. 7
is a roll paper shaft, comprising a shaft portion 10 having a flat portion 17 held by the U-shaped groove bearing 9 of the roll paper holding plate 8;
The cylindrical portion 18 is inserted into the inner side of the roll paper core.

The cylindrical portion 18 is provided with a flat surface 19, to which one end of a rolled paper spring 20 made of a linear spring material is fixed.
The other end of the roll paper spring 20 is inclined along an elongated groove 21 provided in the axial direction of the cylindrical portion 18 of the roll paper shaft 7,
In the free state, as shown by the two-dot chain line, the cylindrical part 1
8, and its tip is bent inward. A disk 6 for regulating the side surface of the rolled paper 1 is fixed to a cylindrical side surface 22 at the boundary between the shaft section 10 and the cylindrical section 18 of the roll paper shaft 7 by an appropriate method. When the cylindrical portion 18 of the roll paper shaft 23 equipped with the roll paper spring 20 and the disc 6 is inserted inside the core 16 of the roll paper 1, the roll paper spring 20 comes into contact with the inside of the core 16, and direction along the groove 21 of the cylindrical portion 18. The roll paper 1 with a pair of roll paper shafts 23 inserted therein is attached to the U-shaped groove bearing 9 on the roll paper holding plate 8 with the plane part 17 of the shaft part 10 of the roll paper shaft 23 parallel to the U-shaped groove 14. Set the roll paper 1 as shown in FIG.

When the roll paper 1 is fed in this state, the roll paper rotates in the direction of the arrow 24, and sliding friction occurs between the surface of the core 16 and the roll paper spring 20. This frictional force, ie, the back tensioner, makes it possible to tension the roll paper 1 and adjust the deviation of the roll paper from side to side. At this time, since the diameter of the shaft portion 10 of the roll paper shaft 23 is larger than the width of the U-shaped groove 14, no rotation occurs within the U-shaped groove bearing 9. This can prevent the roll paper 1 from falling off. Also,
The roll paper 1 can be easily replaced by simply inserting and removing the roll paper shaft 23 into the roll paper 1. Roll paper holding plate 8
The U-shaped groove 14 of the bearing member 15 may be rectangular.
There is no need for

The rolled paper spring 20 may be plate-shaped as shown in FIG. Reference numeral 25 denotes a protrusion provided to make internal contact with the winding core 16.

According to the present invention, the roll paper can be normally fed without shifting to the left or right.

[Brief explanation of the drawing]

FIG. 1 is a front view explaining the conventional example, FIGS. 2 and 3 are a side view and a plan view of FIG. 1, respectively, FIG. A front view illustrating one embodiment, FIGS. 6 and 7 are side views of FIG. 5, respectively.
The plan view and FIG. 8 are perspective views showing another embodiment of the rolled paper spring according to the present invention. 8... Roll paper holding plate, 9... U-shaped groove bearing, 20... Roll paper spring, 23...
...Roll paper shaft.

Claims (1)

[Claims] 1 A pair of roll paper holding plates, a pair of roll paper shafts that are cantilever-supported so as not to rotate by attaching bearing members to the U-shaped grooves of the holding plates, and a pair of roll paper shafts that are attached to the supporting end sides of each of the shafts. a pair of discs which are arranged on the shaft and regulate the sides of the roll paper, and one end of which is attached to a flat part formed on the non-supporting end side of each of the roll paper shafts, and a flat support end formed for attaching the bearing member. A back tension mechanism for rolled paper, comprising a rolled paper spring whose other end faces into a groove formed in a cylindrical portion connected to the roll paper spring, the other end of which comes into elastic contact with an inner wall surface of a rolled paper core.