JPH0696302B2 - Paper feeder for printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Field of Industrial Application The present invention relates to a paper feed mechanism of a printer that can selectively use fanfold paper and cut paper.

(2) Disadvantages of Prior Art Conventionally, in a paper feed mechanism in a printer capable of selectively using fanfold paper and cut paper, when fanfold paper is used, pin feed drive is performed by driving a tractor unit, and at this time, cut paper is used. It is necessary to open the platen pressure roller for driving the paper from the platen. Further, when using cut paper, it is necessary to perform the reverse switching. If it becomes necessary to use cut paper during the use of fanfold paper due to paper handling, it is necessary to completely remove the fanfold paper from the tractor unit before using it. There was a problem that it took time. There are two types of fanfold paper feeding method: a push method that feeds the paper and a pull method that pulls the paper, depending on the arrangement of the tractor unit with respect to the platen.In the latter pull method, the fanfold paper is used while the cut paper is used. The fold paper must be completely removed from the tractor unit, but in the Push method, due to its mechanism,
It is not necessary to completely remove the fanfold paper, and after rewinding the fanfold paper to a predetermined position where it will not be removed from the tractor unit, the cut paper can be set. A mechanism called a book save function is being adopted. As the adopted paper feeding mechanism, a pressure contact opening switching mechanism between a platen and a pinch roller, which is a driving unit for performing friction feed, and a tractor shaft driving selection, which is a tractor unit driving unit, are selected. A clutch mechanism, which also functions as a mechanism for switching between the latter clutch connection and release by the swing motion of the release lever that performs the former operation, or
There are things to do individually.

However, as the conventional clutch mechanism, an idler gear interposed between the idler gear and a tractor gear in a paper feed gear train that uses a paper feed motor as a drive source is moved in the gear axial direction or in the radial direction. In the former case, when engaging with the tractor gear, when the gears do not engage due to interference between the teeth of the gears, or when the tooth tips are engaged during engagement. Due to the collision, the tractor gear would not rotate and the position of the fanfold paper would move. When the latter is moved in the radial direction, the tooth tips collide with each other depending on the relative gear positional relationship and the meshing is not performed reliably, or the tooth tips collide when the tractor gear meshes. There was a problem that the fan fold paper was moved and the position of the fanfold paper was moved. Further, since the tractor shaft is configured to be freely rotatable with respect to an external force in a state where the interlocking with the tractor gear is released by the movement of the idler gear, the fanfold paper has an external force,
Alternatively, there is a possibility that it may come off from the tractor unit due to its own weight, which has a drawback of not being practical. Further, in the conventional example described above, there is a restriction that an operation lever mechanism for contacting and separating the idler gear with respect to the tractor gear must be provided on the side frame side forming the paper feed gear train wheel due to design. There is a drawback in that it is not possible to deal with the arrangement more flexibly than the relationship with other mechanisms that constitute the printer.

(3) Object of the present invention The present invention is intended to eliminate the above-mentioned drawbacks, and the first object of the present invention is to smoothly and reliably perform switching selection between fanfold paper and cut paper with a simple structure. Another purpose is to keep the fanfold paper in a predetermined state by applying a friction load to the tractor shaft when the tractor drive is opened. Still another object is to prevent the deterioration of the paper feeding accuracy, and to improve the operability with a mechanism for selecting the drive stop of the cut paper and the fanfold paper in one operation. It is possible to install the operating lever for selecting the tractor drive at an arbitrary position without increasing the number of parts.

(4) Outline of the Present Invention According to the present invention, the gear train for driving the paper feed using the paper feed motor as the drive source can be always engaged and rotated regardless of the paper feed drive system switching operation by selecting fanfold paper or cut paper. The tractor gear is arranged on the tractor drive shaft so that it can rotate independently of the shaft and is arranged adjacent to the gear and integrally rotatable with the shaft. Has a tractor clutch that is provided with a connecting means that allows both members to integrally rotate when the tractor clutch moves in the tractor drive axis direction via elastic means at the opposing portion of the tractor gear and the tractor clutch. And further comprising tractor drive shaft decoupling means for decoupling the tractor gear and tractor clutch against the elastic means. The purpose was achieved by and.

(5) Description of Embodiment Hereinafter, a paper feeding device of the printer of the present invention will be described based on an embodiment shown in FIGS. 1 to 5. 1 is a known tractor unit that performs pin feed, and a side frame
The tractor drive shaft 2 and the side frame 4 which are rotatably supported via guide bushes 5 mounted on 4A and 4B.
Pin holes of fanfold paper to be used, which are supported via A and 4B, and are axially supported by a tractor unit guide shaft 3 whose shaft end is screwed with a nut 6 so as to be slidable in the axial direction. Is mounted on a tractor pin wheel formed so as to rotate integrally with the drive shaft 2, locks the tractor unit 1 at a predetermined paper width position, and rotates a paper feed motor, platen knob, etc. to a predetermined print start position. Used for paper feed set. At one shaft end of the tractor drive shaft 2 protruding to the outside of the side frame 4A, a tractor gear 7 disposed so as to be rotatable independently of the rotation of the shaft, and a shaft pin 8 are integrally provided on the tractor gear 7. It has a tractor clutch 9 arranged so as to be rotatable, and the clutch 9 is prevented from disengaging from the shaft by a stop ring 10. The tractor gear 7 and the tractor clutch 9 have knurls 7A and 9A with a fine pitch for connecting and rotating by relative movement in the tractor drive axis direction,
Both members are formed to be connected by the spring force of a spring 11 and a spring receiver 12 arranged at the shaft end of the tractor drive shaft 2 protruding outside the other side frame 4B. Reference numeral 13 denotes a platen shaft on which a platen 14 is mounted, and like the tractor drive shaft 2, is rotatably supported via guide bushes 15 mounted on the side frames 4A and 4B, and
A platen gear 16 that forms a part of a paper feed train is provided at a shaft end protruding outside the side frame 4A via a spring pin 17 so as to rotate integrally with the shaft 13. 18
Is a release gear shaft, and as shown in FIG. 3 and FIG.
The pinch roller 21, which is pressed against the platen 14 by the spring force of the leaf spring 20 locked to the paper chute 19, releases the pressure. The cross section of the shaft has a semicircular shape, and the shaft 18
The swinging rotation of the spring resists the spring force of the leaf spring 20.
The pressure release of the pinch roller 21 is performed by releasing the pressing engagement of 20. Reference numeral 22 is a release gear mounted on the shaft end of the release gear shaft 18 protruding outside the side frame 4B so as to rotate integrally with the shaft. 24 is the platen 14
It is a release lever for releasing the pressure of the pinch roller 21 that is pressure-bonded to the pin 25 that is planted in the side frame 4B.
It is formed so that it can swing around. The lever 24
Includes a tooth portion 24 for engaging with the release gear 22 and releasing the pressure of the pinch roller 21 pressure-bonded to the platen 14.
In A and the swinging motion, the tractor drive shaft 2 is pushed and moved against the spring force of the spring 11, and the knurl 9A of the tractor clutch 9 in the connected state is moved to the tractor gear 7
The cam 24B for separating the knurl 7A from the knurl 7A or vice versa is provided with a cam 2B as shown in FIG.
The release lever 24 is formed on a circle with the fulcrum as a fulcrum, and the selective positioning of the release lever 24 with respect to the tractor feed and the friction feed is restricted between the release gear 22 and the tooth portion 24A of the release lever 24. It is formed as follows. 26 is a stop ring for preventing the lever 24 from coming off the pin 25. The paper feed gear train is shown in Fig. 1,
As shown in FIG. 2, using a pinion 35 of the paper feed motor as a drive source, an idler gear 28 rotatably arranged on a pin 27 planted in the side frame 4A engages with the platen gear 16 and the idler gear 28. , Side frame
4A meshes with an idler gear 30 rotatably disposed on a pin 29 planted in 4A, and further meshes with the idler gear 30 and the tractor gear 7. As a result, the platen gear 16 and the tractor are driven by the rotation of the paper feed motor. The gear 7 and the gear 7 are formed so as to be capable of decelerating rotation at the same pitch. The stop rings 31, 32 connect the idler gears 28, 30 to the pins 27, 29.
This is to prevent the user from leaving.

Next, the operation operation will be described. The state shown in FIG.
The release lever 24 is set to the fanfold paper setting position shown in FIG. In this state, the pinch roller 21 to be pressure-bonded to the platen 14 is in a state of pressure-release by pressing the leaf spring 20 down by the release gear shaft 18 having a semicircular cross section. Further, the tractor drive shaft 2 is in a state where it is not pressed by the release cam 24B, and the tractor drive shaft 2 is driven by the spring force of the spring 11.
Is pulled in the direction of arrow B to connect the tractor clutch 9 to the tractor gear 7 via both knurls 9A and 7A. Therefore, in this case, the tractor drive shaft 2 integrally rotates through the tractor clutch 9 together with the tractor gear 7 that is interlocked by the drive of the paper feed motor.
Next, in the case of using the switching set to cut paper while the fanfold paper is being used, the fanfold paper 33 guided as shown by the imaginary line in FIG. 2 is reversed by a paper feed motor or a platen knob (not shown). Rewind to the position A where the paper is not removed from the tractor unit 1. Then, in this state, the release lever 24 is moved to the third position.
The state shown in the figure (fanfold paper set position)
To the cut paper set position shown in FIG. In this state, since the release lever 24 rotates to the left from the state shown in FIG. 3 to rotate the release gear 22 to the left, the engagement of the pinch roller 21 with the leaf spring 20 for crimping due to the semicircular axial cross section of the release gear shaft 18. When the combined state is released, the pinch roller 21 is pressed against the platen 14 by the spring force. On the other hand, the tractor drive shaft 2 is moved by the release cam 24B against the spring force of the spring 11 in the direction of arrow C in FIG. 1, so that the knurl 7A and the tractor clutch 9 of the tractor gear 7 in the connected state. The connection with the knurled 9A is released. The cut sheet set through the cut sheet guide 34 shown in the phantom line in FIG. 2 is inserted and guided in the direction of the arrow D by the guide 34 and the paper chute 19, and the crimping portion between the pinch roller 21 and the platen 14 is pressed. Contact the paper feed motor,
Alternatively, it is set at a predetermined printing position by rotating a platen knob or the like. By controlling the rotation of the paper feed motor,
The paper feed control of the cut paper is performed by the platen 14 and the pinch roller 21 which are pressed and rotated based on the rotation of the platen gear 7 which is interlocked via the paper feed wheel train. Needless to say, with the tractor drive shaft 2, via the tractor clutch 9,
Since the interlocking is released, the tractor drive shaft 2 does not rotate, and the tractor gear 7 as the interlocking medium of the paper feed train wheel rotates independently of the tractor drive shaft 2. At this time, since the tractor drive shaft 2 is subjected to a frictional load due to the spring force of the spring 11, the tractor drive shaft 2 rotates even if an external force is applied to the fanfold paper set in the tractor unit 1. It has a difficult structure. As described above, the present invention provides the clutch mechanism for the tractor drive shaft 2 and the pinch roller 21 for the platen 14.
Although the pressure release mechanism has been described as a suitable example in which both functions are performed in one action by swinging the release lever 24, it may be possible to perform the function independently from the balance with the peripheral printer device. Good. Further, similar to the above, in the clutch mechanism, the tractor clutch 9 integrated with the tractor drive shaft 2 is disengaged from the tractor gear 7 by the movement of the tractor drive shaft 2, but the mounting position of the spring 11 is Is usually formed so as to be connected to the tractor gear 7 by the spring force, and when the tractor clutch 9 is disengaged, the tractor clutch 9 is resisted against the spring force via the cam means or the like, and If it is formed so as to be separated from 7, it is not always necessary to move the tractor drive shaft 2. Also, the arrangement position of the release lever, etc. should be adjusted in consideration of the surrounding printer devices.
Either side frame can be used. Also, as an example of the connecting means, knurls 9A, 7A are formed at the facing portions of the tractor clutch 9 and the tractor gear 7. However, as long as the structure is such that the knurls 9A and 7A can be integrally rotated by relative movement in the axial direction, rubber and felt can be used. A high friction material such as the above may be used, and the structure including the material is arbitrary.

(6) Effect of the Present Invention As described above, according to the present invention, a printer capable of using fanfold paper and cut paper is provided. In the setting work for switching to cut paper during use of fanfold paper, the fanfold paper is removed from the tractor unit. You can change the set of cut sheets without removing them. As the switching mechanism, a tractor clutch that rotates in unison with the tractor drive shaft is always kept in mesh without releasing the meshing state of the idler gear in the paper transport train based on the drive of the paper transport motor as compared with the conventional mechanism. With a simple structure in which the shaft is interlocked with the paper feed drive by a moving action in the direction of the tractor drive shaft, tractor drive selection switching can be performed smoothly and reliably, and in addition to the conventional train wheel mechanism, Since the gears forming the part are not pulled out, the deterioration of the paper feeding accuracy can be prevented. In addition, when using fanfold paper to cut paper, the fanfold paper rewound to the tractor unit section has a structure in which the friction load by the spring that forms the clutch mechanism on the tractor drive shaft is automatically applied. It is practical because it is easy to hold the fanfold paper at a fixed position without being separated from the tractor unit by external force. In addition, it has the function of releasing the pinch roller pressure from the printer by one-action operation of the release lever and the clutch function of the tractor drive shaft. It also has a practical effect that it can be arbitrarily selected and designed.

[Brief description of drawings]

1 to 5 show one embodiment of the paper feeding mechanism in the printer of the present invention. FIG. 1 is the schematic plan view and FIG.
1 is a schematic left side view mainly showing a paper feed train arranged on the left side surface in FIG. 1, and FIGS. 3 and 4 are fanfold papers formed on the right side surface in FIG. FIG. 5 is a schematic side view showing a state corresponding to each release lever set position associated with the use of cut paper, and FIG. 5 is a sectional view taken along the line AA in FIG. 4, showing a cam curve of the release lever cam. 2: Tractor drive shaft, 7: Tractor gear 9: Tractor clutch, 18: Release gear shaft 22: Release gear, 24: Release lever

Claims (1)

[Claims] Claim: What is claimed is: 1. A tractor gear, which is always interlocked with the drive of a paper feed motor, is arranged on a tractor drive shaft so as to be able to rotate independently of the rotation of the tractor drive shaft, and a tractor clutch provided in parallel with the gear. And a connecting means for integrally rotating the tractor gear and the tractor clutch arranged in parallel with the shaft by relatively moving the tractor gear in the tractor axial direction. The connecting means has elastic means for constantly urging the tractor clutch in the connecting direction and connection releasing means for releasing the connection at appropriate times against the elastic means. A printer characterized in that a rotational friction load is applied by the elastic means to suppress free rotation of the tractor shaft at the time of disconnection. That paper feeder.