JPH0632957B2 - Paper feed switching mechanism of printer - Google Patents

Description

[Detailed Description of the Invention] -Industrial field of application-The present invention relates to switching of a paper feeding device during continuous form processing and single form processing in a printer that can use continuous form paper and single form paper as printing paper. It is related to the mechanism.

-Technical background-A printer capable of processing both continuous form paper and single-cut form paper is provided with two paper feeding devices for continuous forms and single forms. Usually, continuous form sheets are fed by a pin driving device such as a tractor or a sprocket that engages with a marginal punch hole of the sheet, and single-cut sheets are fed by a frictional force by sandwiching the sheets with a pair of rollers. When converting the paper, it is necessary to switch between the two paper feeding devices.

On the other hand, as one means for adjusting the distance between the print head and the platen, that is, the so-called head gap according to the thickness of the printing paper to be inserted, a structure is known in which a cam is used to move the platen toward and away from the print head. (For example, JP-A-5
6-77177, JP-A-59-89187, etc.).

-Prior Art and Problems-In a conventional printer, a switching mechanism of a paper feeding device and a head gap adjusting mechanism are provided as independent devices. As a result, there are problems that the number of components of the printer is increased, the manufacturing and assembling of the components are troublesome, and the switching operation at the time of paper conversion becomes complicated.

-Object of the Invention-The present invention focuses on the fact that the head gap is always adjusted when converting printing paper, and the head gap adjusting mechanism using a cam and the switching mechanism of the paper feeding device are linked. By this, adjustment of the head gap and switching of the paper feeding device at the time of paper conversion can be performed by a single operation system in a series of operations, thereby reducing the number of parts and assembling man-hours of the printer, and at the time of paper conversion. The purpose is to simplify the operation or control.

-Structure of the Invention-The switching mechanism of the paper feeding device of the printer of the present invention comprises a pin driving device 5 for feeding continuous form paper, and an engagement / disengagement mechanism 35 for transmitting and blocking the rotational driving force for the pin driving device.
Paper feed rollers 3 and 4 for feeding single-cut sheets and a nipping force applying mechanism 19 and 2 for increasing or decreasing the paper nipping force of the paper feed rollers.
0 and 21, a platen 2 mounted so as to be close to and away from the print head 1, a rotary cam 41 for advancing and retracting the platen 2 toward the print head 1 by a reciprocating rotation operation, the engaging / disengaging mechanism 35, and A second cam 50 having engaging portions 53 and 54 for engaging the clamping force applying mechanisms 19 and 20, and an engaging pair 51 for transmitting the rotation at the rotating end portion of the rotating cam 41 to the second cam 50, And 52.

The engaging portions 53 and 54 of the second cam engage the engagement / disengagement mechanism 35 when the second cam rotates to one side to transmit the rotational driving force to the pin driving device 5 and also the clamping force applying mechanism 19 Two
0 and 21 are operated in a direction to reduce or remove the paper clamping force of the paper feed rollers 3 and 4, and when rotated to the other, the engagement / disengagement mechanism 35 is detached to cut off the rotational drive force of the pin drive device 5. In addition, the clamping force applying mechanisms 19, 20, and 21 are provided in a positional relationship of operating in a direction of increasing the sheet clamping force of the sheet feeding rollers 3 and 4, and the rotating cam 41 is rotated to any one of the rotating end portions. By doing so, the conversion between the continuous form processing state and the single-cut processing state is performed.

-Operation- In the apparatus having the above-described configuration, switching between the continuous form and the single form is performed by largely rotating the head gap adjusting cam 41 in either direction. The contour curve of the cam 41 can be shaped so that it gradually lowers from the neutral position P to both sides (the platen 2 descends), and when a new sheet is inserted, the cam 41 changes according to the type of sheet. The head gap is opened by turning largely to the right or left, the second cam 50 is turned to the right or left by utilizing this large turning operation, and the pin driving device 5 is turned depending on the turning position of the second cam. The driving systems 34, 35, 36, 37 and the pinching force applying mechanisms 19, 20, 21 for the paper feed rollers 3, 4 are switched. The second cam 50 can be linked to the drive system and the clamping force applying mechanism by using members such as gears, links, levers and cams according to the structure of each mechanism.

The contour curve 41a of the cam 41 may be formed symmetrically on both sides of the neutral position P, or may be formed asymmetrically on both sides of the neutral position P so that the head gap of the head gap is formed on either side of the contour curve 41a. It is also possible to make adjustments. When the both sides are formed symmetrically, the head gap is adjusted by returning the cam 41, which has been largely rotated once, to the neutral position P after the insertion of the paper to the rotational position corresponding to the predetermined head gap. When the contour curve 41a of the cam 41 is asymmetric and the head gap is adjusted only on one side of the contour curve 41a, the cam 41 that has been largely rotated is used.
Is returned to the neutral position P after the paper is inserted, and is rotated further toward the side for adjusting the head gap to adjust the head gap. The cam 41 and the second cam 50 are engaged with each other when the cam 41 is largely rotated so that the second cam 50 does not rotate due to the rotation operation when adjusting the head gap. They must be linked by a linking means that does not engage when rotated in the middle of the end. Such a linking means can be realized by an engaging pair having a floating portion in the intermediate portion like the protrusion 52 and the elongated hole 51.

-Embodiment- FIG. 1 is a view showing an embodiment of the present invention, FIG. 1 is a side view,
1 is a plan view seen from the portion A in FIG. 1, FIG. 3 is a sectional view in a portion B in FIG. 2, FIG. 4 is a sectional view in a portion C in FIG. 2, and FIG. It is a perspective view which shows the engagement / disengagement mechanism of the drive system of a pin drive device.

In the figure, 1 is a print head, 2 is a platen, 3 and 4 are feed rollers for feeding single-cut sheets arranged on both sides of the platen 2,
Reference numeral 5 is a tractor for feeding continuous paper. Feed roller 3,
Reference numeral 4 is a drive roller 3a axially attached to a frame (Fig. 2),
4a and driven rollers 3b and 4b that are pivotally attached to the tips of swingable arms 9 and 10 fixed to the fulcrum shafts 7 and 8 and are in contact with the drive rollers 3a and 4a.
The platen 2 is mounted on a tip end of an arm 12 swingable around a shaft 11 of one drive roller 4a so as to be vertically swingable.

At one end of the fulcrum shaft 7,8, a lever 13,1 extending downward is provided.
4 is fixed, weak tension springs 15 and 16 are stretched between the levers 13 and 14 and appropriate immovable members, and further, wide and narrow members pivotally attached to fulcrum pins 17 and 18 planted in the immovable members. The tips of the two arms 19, 20 are provided so as to abut the levers 13, 14, and a strong tension spring 21 is stretched between the base ends of the arms 19, 20 to attach the springs 15, 16 and 21. The driven rollers 3b and 4b are driven by the driving roller 3a and
It is suppressed by 4a.

The platen 2 and the drive rollers 3a, 4a are collectively driven by the motor 33 by the timing belts 30, 31, 32 (FIG. 2). The tractor 5 is the drive roller 4
a from the gear 34 fixed to the other end of the shaft 11 to the intermediate gear 3
5 and 36 and the timing belt 37, the intermediate gear 35 is axially slidably mounted on the shaft 38 of the intermediate gear 35 (see FIG. 5). With this, the meshing with the gear 34 is disengaged, and the transmission of the rotational force to the tractor 5 is blocked.

Below the platen 2, a cam shaft 40 parallel to the platen 2 is provided.
Is mounted on a fixed position, and a cam 41 fixed to both ends of the cam shaft 40 and a roller 43 rotatably mounted on the shaft 42 of the platen 2 come into contact with each other to support the platen 2. There is. The cam 41 has a shape that supports the platen 2 highest at the neutral position P and descends as the platen 2 moves away from the neutral position P. When the cam shaft 40 is rotated by a driving device (not shown), the platen 2 moves up and down by the action of the cam 41, and the gap (head gap) between the platen 2 and the tip of the print head 1 at a constant height. Is adjusted.

A second cam 50 is rotatably attached to one end of the cam shaft 40, and a pin 52 set up on the cam 41 is loosely fitted in an arcuate groove 51 provided in the second cam. The cam 41 is engaged. The intermediate gear 35 is attached to the second cam 50.
The wedge member 53 for sliding the arm 1 is projected and the arm 1
A protrusion 54 for operating the 9 and 20 is formed. That is,
The wedge member 53 extending from the second cam 5C is inserted inside the intermediate gear 35 as shown in FIG.
1, the intermediate gear 35 is pushed outward by the wedge slope 53a when it rotates clockwise in FIG. 1, and the base extensions 19a and 20a of the arms 19 and 20 are connected to the second cam 50.
The extension parts 19a, 20a
When the arm is pushed, the arms 19 and 20 swing so as to narrow each other, and the contact between the tips of the arms 19 and 20 and the levers 13 and 14 is released. Where the first
Reference numeral 55 in the drawing is a pin that links the base end extension portions 19a and 20a of the arm with each other, and reference numeral 56 in FIG. 5 is for returning the intermediate gear 35 to the original position in which it meshes with the gear 34 when the wedge member 53 is withdrawn. Is the spring of.

Next, the operation of the illustrated device will be described. FIGS. 1 to 5 show a state during printing of cut sheets, in which the wedge member 53 is inserted inside the intermediate gear 35 and pushes the gear 35 outward. The meshing with the gear 34 is released, and the tractor 5 is not driven. Further, the protrusion 54 provided on the second cam 50 is provided on the base end extension portions 19a, 2a of the arms.
0a and the tips of the arms 19 and 20 are levers 1
The driven rollers 3b and 4b are pressed against the springs 3 and 14 and the spring 1
Drive rollers 3a, 4 are formed by both 5, 16 and spring 21.
It is oppressed by a strong force.

When printing continuous form paper, the cam 41 is rotated further 90 degrees counterclockwise from its neutral position P from the state shown. Then, the platen 2 is lowered to open the head gap for inserting a sheet, and at the same time, the pin 52 set in the cam 41 is raised.
Comes into contact with the lower end of the arcuate groove 51 to rotate the second cam 50 counterclockwise by approximately 30 degrees from the state shown in FIG. The soot and the wedge member 53 retreat from the inside of the intermediate gear 35, return to the original position where the gear 35 meshes with the gear 34, the drive system to the tractor 5 is connected, and the protrusion provided on the second cam 50. 54 rotates downward and the protrusion 54 causes the proximal end extension parts 19a, 20a of the arm to move.
a is pushed downward. Then, the arms 19 and 20 swing in a direction in which they narrow each other, and the tips of the arms 19 and 20 and the lever 1
Since the pressing contact with 3, 14 is released, the driven roller 3b,
4b is a weak force of only the springs 15 and 16, and the driving roller 3a,
It comes into contact with 4a.

In this state, when the cam 41 is rotated clockwise to adjust the head gap according to the thickness of the inserted sheet, the pin 52 simply loosens in the arc groove 51 and the cam 41 at this time is rotated. Is not transmitted to the second cam 50, and the second cam 50 is provided with the protrusion 54 and the arm base end extension portions 19a, 20a.
It is held in a fixed position by the frictional force between the cam 41 and the left rotation end of the cam 41, and the continuous book processing state set is held. Cam 41
When the contour curve 41a is formed symmetrically with respect to the neutral position P, the adjustment operation of the head gap at this time is performed on the right side portion of the contour curve 41a of the cam 41 in the figure. That is, after the cam 41 is once turned largely leftward, the cam 41 may be returned clockwise from the turning end toward the neutral position P to hold the cam 41 at a predetermined position corresponding to the sheet thickness. If the head gap adjustment operation is performed only on the left side of the contour curve 41a of the cam 41 in the figure, the cam 41 is rotated right from the left rotation end to the neutral position P, and the paper thickness is changed from the neutral position P. The cam 41 may be further rotated rightward to a predetermined position corresponding to. Contour curve 41 of cam 41
It is easier to operate or control the head a when adjusting the head gap, if it is formed so that the rotation angle thereof and the amount of elevation of the platen 2 have a linear relationship. If the head gap is adjusted only by (2), the cam 41 can be manufactured and adjusted more easily because only the portion having the contour curve satisfying the above-mentioned linear relationship may be formed.

From the above-mentioned continuous book processing state, the cam 41 is rotated 90 degrees right from its neutral position P, the pin 52 of the cam 41 is brought into contact with the upper end of the arc groove 51, and the second cam 50 is rotated clockwise. It becomes the single-cut processing state shown. Even when the cam 41 is rotated counterclockwise from the right rotation end in order to adjust the head gap, the single-cut processing state is maintained, as in the continuous form processing.

In the apparatus of the illustrated embodiment, the continuous form paper is inserted into the head gap from the left side of the figure and the cut sheet is inserted into the head gap from the right side of the figure. The opening and closing of the guide plates 60 and 61 at this time is also performed in association with the rotational movement of the cam 41. That is, as shown in FIG. 4, the operating arms 62 and 63 extend from the guide plates 60 and 61 toward the cam shaft 40, and when the cam 41 reaches the right or left turning end, the inside of the cam 41 is closed. The guide opening / closing cam 64 and the operation arm 62 or 63 attached to the above are brought into contact with each other so that the guide 60 is opened when the continuous paper is inserted and the guide 61 is opened when the cut sheet is inserted. Further, since the illustrated apparatus has a structure in which the continuous form paper is pushed and fed by the tractor 5, the drive rollers 3a, 4 of the paper feed rollers are also used during the continuous form feed.
A and the driven rollers 3b and 4b are pressed with a weak force to act as an auxiliary paper feeding force. However, in the case of a printer in which the tractor 5 is a tension type, the springs 15 and 16 shown in FIG. Installed in the direction, and the follower rollers 3b, 4b during continuous feeding
Can be completely separated from the drive rollers 3a and 4a.

-Effects of the Invention-According to the configuration of the present invention described above, it is possible to switch between the continuous form and the cut sheet feeding device at the same time and in one operation by utilizing the rotation of the head gap adjusting cam. Therefore, the operation at the time of paper conversion is simplified, the trouble caused by the operation mistake can be avoided, the number of components of the apparatus can be reduced, and the number of assembling steps can be reduced. Further, in the apparatus of the illustrated embodiment, the opening / closing operation of the guide plate at the time of inserting the paper is also performed in association with the rotation of the cam for adjusting the head gap, so that the structure of the apparatus and the operation at the time of paper conversion are simpler. Therefore, the control structure for automating these operations is also simplified.

[Brief description of drawings]

FIG. 1 is a view showing an embodiment of the present invention, FIG. 1 is a side view,
2 is a plan view seen from the portion A in FIG. 1, FIG. 3 is a sectional view in a portion B in FIG. 2, FIG. 4 is a sectional view in a portion C in FIG. 2, and FIG. It is a perspective view which shows the engagement / disengagement mechanism of the drive system of a pin drive device. In the figure, 1 is a print head, 2 is a platen, 3 and 4 are paper feed rollers, 5 is a tractor, 7 and 8 are fulcrum shafts, 12 is a platen support arm, 13 and 14 are levers, 17 and 18 are fulcrum pins, Reference numerals 19 and 20 are arms, 21 is a tension spring, 35 is an intermediate gear to be engaged and disengaged, 40 is a cam shaft, 41 is a head gap adjusting cam, 50 is a second cam, 51 is an arc groove, 52 is a pin, 53 is 53 A wedge member projectingly provided on the second cam, 54 is a projection, 5
6 is a return spring.

Front Page Continuation (72) Inventor Yoshihiro Ito 98 Uno-nu, Unoku-cho, Hebei-gun, Ishikawa 2 User Tsuku Denshi Kogyo Co., Ltd. (72) Inventor Tadashi Okubo 98 Uno-nu, Unoku-cho, Kawakita-gun, Ishikawa Prefecture No. 2 within Utsuku Electronics Co., Ltd. (56) Reference JP-A-57-18282 (JP, A)

Claims (1)

[Claims] 1. A pin driving device (5) for feeding continuous form paper, an engagement / disengagement mechanism (35) for transmitting and blocking rotational driving force to the pin driving device, and a paper feed for feeding single-cut sheets. Laura (3),
(4), a nipping force applying mechanism (19), (20), (21) for increasing or decreasing the paper nipping force of the paper feeding roller, and a platen mounted to face the print head (1) so as to be close to and separated from each other. (2), a rotary cam (41) for advancing and retracting the platen (2) toward the print head (1) by reciprocating rotation operation, the engagement / disengagement mechanism (35) and clamping force applying mechanisms (19), (20). A second cam (50) having engaging portions (53) and (54) for engaging with the second cam (50), and a member for transmitting the rotation at the rotating end portion of the rotary cam (41) to the second cam (50). The engaging portions (53) and (54) of the second cam engage with the engagement / disengagement mechanism (35) when the second cam rotates to one side. To transmit the rotational driving force to the pin driving device (5), and at the same time the pinching force adding mechanism (19),
Operate (20) and (21) in the direction to reduce or remove the paper clamping force of the paper feed rollers (3) and (4), and when they rotate to the other side, they disengage the engagement / disengagement mechanism (35) to release the pin. The rotation driving force of the drive unit (5) is cut off and the clamping force applying mechanisms (19), (20), (21) are operated in the direction to increase the sheet clamping force of the paper feed rollers (3), (4). The printer paper, which is provided in a positional relationship, is characterized in that the rotary cam (41) is rotated to any one of the rotary end portions to convert the continuous form processing state and the single-cut processing state. Switching mechanism of the feeding device.