JPH0432287Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a pin tractor that feeds printing paper having feed holes formed on both sides at required intervals to a printing position of a printing device.

[Prior Art] Conventionally, this type of pin tractor has a pair of left and right frames, two pulleys rotatably supported at both ends of the frames, and a pulley that is stretched between the pulleys and It consisted of an endless belt with many pins protruding from it at equal intervals.

This pin tractor has two pulleys, one of which is inserted through a drive shaft that transmits the driving force of a drive source such as a pulse motor or DC servo motor, and the other pulley or frame is a guide provided parallel to the drive shaft. While inserted through the shaft, they were positioned on the left and right sides of the paper feed path of the printing device with a distance equal to the width of the printing paper.

Then, the printing paper is mounted on the pin tractor so that the feed holes drilled at both ends of the paper engage with the pins of the pin tractor, and then the drive pulley is rotationally driven via the drive shaft by the drive source. The rotation drives the belt between the two pulleys. As the belt rotates, the pin moves and the printing paper is fed to the printing position.

[Problems to be Solved by the Invention] By the way, when the feed holes at both ends of the printing paper are engaged with the pins of the pin tractor, the central position between the pulleys becomes loose due to its own weight. The amount of slack increases as the printing paper becomes wider, causing printing defects and paper jams. Therefore, in order to prevent the printing paper from loosening, the pin tractor is positioned and fixed to the drive shaft and the guide shaft so that the printing paper is pulled outward in the width direction using pins.

At this time, if the force with which the pin tractor pulls the printing paper is too strong, the feed hole may be torn or the portion of the belt located between the pulleys may be pulled, causing the belt to become bent in the feeding direction. If the printing paper was fed in this state, the pins and the feeding holes would no longer engage, and the printing paper would be fed to the printing position crooked, or the printing paper would be damaged, making it impossible to feed the paper.

It is also conceivable to attach a guide member to the lower side between the pulleys that slidably abuts against the back side of the belt to prevent it from loosening inwardly, but if this is done, the belt will not loosen due to the sliding friction. There were problems such as wear and tear, decreasing durability, and generating large frictional resistance, requiring large driving force.

[Purpose of the invention] This invention was devised to solve the problems of conventional pin tractors. To provide a pin tractor that can reliably feed paper without becoming unable to feed, improves the durability of the belt, and can be driven with less driving force.

[Means for Solving the Problems] The pin tractor of the present invention includes a pair of left and right frames, a pulley that is rotatably supported at both ends of the frame and has a collar on the side surface, and a pulley that has a collar on the side. An endless belt is sandwiched between pulleys, and has a large number of pins protruding at equal intervals along the outer circumferential surface, and the belt is rotatably supported by the frame between the pulleys, and the belt is attached to the side surface. It consists of a guide roller on which a collar is formed to sandwich the belt.

[Function] In the pin tractor of the present invention, when the printing paper is attached to the pin tractor so that it does not loosen in the width direction, the sides of the belt are pinched by the collars of the guide rollers, so that movement from side to side is restricted. It is pulled by the printing paper and rotated by the drive source without being bent between the two pulleys.

[Embodiment] Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS. 1 to 3.

In the printing device (not shown), a drive shaft 11 is rotatably supported by a drive source (not shown) such as a pulse motor or a DC servo motor so as to extend parallel to the platen, and a drive shaft 11 is rotatably supported by a drive source (not shown) such as a pulse motor or a DC servo motor. A parallel guide shaft 12 is supported. A pair of left and right pin tractors 14 of this embodiment are arranged between the drive shaft 11 and the guide shaft 12 for transporting printing paper (not shown) to a printing position.

Between the pair of left and right frames 15 of this pin tractor 14, the front position (left position in FIGS. 1 and 2) and the rear position (right position in the same figures) are as follows:
Pulleys 16 and 26 are rotatably supported by support parts 18 and 28. The pulleys 16, 26 have a large number of teeth formed at equal intervals along the circumferential surface, and collar portions 17, 27 are formed on the left and right sides. Further, the support portion 28 has an insertion hole 29 into which the drive shaft 11 is inserted. The insertion hole 29 of the pulley 26 located at the rear position between the frames 15
The drive shaft is inserted through the pulley 26, and the pulley 16 at the front position becomes a driven pulley.

An endless toothed belt 21 having teeth 23 on its inner circumferential surface that engages with the teeth of both pulleys 16 and 26 is stretched between the two pulleys 16 and 26, and a printing paper (not shown) is wrapped around the outer circumferential surface of the endless toothed belt 21. A large number of pins 22 that fit into the feed holes (not shown) are protruded at equal intervals. This toothed belt 21 has both pulleys 16, 2
6, the teeth of the pulleys 16 and 26 engage with the teeth 23 on the inner peripheral surface, and are driven to rotate as the drive pulley 26 rotates. At this time, as shown in FIG. 2, a part of the side surface of the belt 21 is
7 and 27.

Further, a roller with a flange 36 having a flange portion 37 on the side surface is rotatably supported approximately in the center between the frames 15, and the guide shaft 1
A hole 38 into which 2 is inserted is transparently provided. As shown in FIG. 3, this flanged roller 36 restricts the downward movement of the toothed belt 21 stretched between the pulleys 16 and 26 on its circumferential surface, and also uses its flanged portion 37 to prevent the belt from moving downward. Hold the sides of 21.

Incidentally, the toothed belt 21 has both pulleys 16 and 2.
6, as shown in FIGS. 2 and 3, the upper surface of the roller 3
It is located above the outer peripheral surfaces of the collar portions 17, 27, and 37 of No. 6, and guides the printing paper by this upper surface.

Outside of the frame 15 (left side in Figures 1 and 2)
At the upper end of the frame 15a, a guide plate 31 that maintains engagement between the feed hole of the printing paper and the pin 22 of the toothed belt 21 is rotatably supported by a pair of front and rear shaft supports 32. It can be opened and closed on the top surface. A through hole 33 is formed in this guide plate 31 to guide the movement of the pin 22 when the guide plate 31 is closed.

In the pin tractor 14 configured as described above, the guide shaft 12 is inserted into the hole 38 of the flanged roller 36 and the insertion hole 29 of the drive pulley 26.
and is slidably supported relative to the drive shaft 11, thereby making it possible to adjust the distance between the two in accordance with the width of the printing paper.

When mounting printing paper on the pin tractor 14 configured as described above, the left and right pin tractors 14 are slid with respect to the drive shaft 11 and the guide shaft 12, and the distance between them is adjusted according to the width of the printing paper. After adjusting the position, the guide plate 31 is opened, the printing paper feed hole is fitted into each pin 22 of the toothed belt 21, and the guide plate 31 is closed.
As a result, the through hole 33 of the guide plate 31 and the tip of the pin 22 engage with each other, and the guide plate 31 maintains the engagement between the feed hole of the printing paper and the pin 22. In this state, the drive pulley 26 on which the drive shaft 11 is rotationally driven rotates, and the toothed belt 21 is moved between the drive pulley 26 and the driven pulley 16.
26 and the collar portion 37 of the collar roller 36, the roller rotates while being held at its sides.
Because the flanged roller 36 rotates in this way,
There is almost no wear due to sliding and almost no sliding resistance, so the belt 21 suffers little wear and can be driven with a small driving force. As the toothed belt 21 rotates, the pin 22 moves between the frames 15 from the front to the rear, and the printing paper is guided between the upper surface of the toothed belt 21 and the guide plate 31 and sent to the printing position.

Here, when the printing paper is attached to the pin tractor 14, if the vicinity of the center in the width direction of the printing paper is slack due to its own weight, the pin tractor 1
4 along the drive shaft 11 and the guide shaft 12 in the direction in which the distance between them increases to take up the slack in the printing paper. This allows the printing paper to be fed to the printing position without paper jamming. At this time, the sides of the toothed belt 21 are clamped by the collar portion 37 of the collar roller 36 to restrict movement from side to side, so the toothed belt 21 is pulled by the printing paper and rotates in the circumferential direction. However, it does not become bent. Therefore, the printing paper is sent to the printing position without being bent or damaged.

[Effects of the invention] As detailed above, the pin tractor of the invention includes a pair of left and right frames, a pulley that is rotatably supported at both ends of the frame and has a flange on the side surface, and a flange of the pulley. an endless belt that is held between pulleys and has a large number of pins protruding at equal intervals along its outer circumferential surface; Since the belt is formed of a guide roller with a collar formed to sandwich the belt, even if the printing paper is attached to the pin tractor in a state where it is stretched in the width direction, the belt will be held in place by the collar of the guide roller. Since it is held in place and its movement from side to side is restricted, it is pulled and rotated by the printing paper without being bent. Therefore, the pin tractor of the present invention can perform an accurate and reliable paper feeding operation without causing the printing paper to be sent to the printing position in a bent state, or preventing the feeding operation from being disabled due to damage to the feed hole or the like.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view of an embodiment embodying the present invention, Fig. 2 is a perspective view thereof, and Fig. 3 is an exploded perspective view of an embodiment embodying the present invention.
- It is a sectional view taken along line 3. In the figure, 15 is a frame, 16 and 26 are pulleys,
17, 27 are collar parts, 21 is a belt, 22 is a pin, 36 is a guide roller (roller with a collar), 37
is the brim part.

Claims (1)

[Claims for Utility Model Registration] A pair of left and right frames, a pulley that is rotatably supported at both ends of the frame and has a flange on the side surface, and a pair of pulleys that are held between the flange portions of the pulleys. An endless belt that is hung around and has a number of pins protruding at equal intervals along the outer circumferential surface, and a collar portion that is rotatably supported by the frame between the pulleys and that holds the belt between the sides. A pin tractor comprising: a guide roller;