JPH03112693A - Pressure roller supporting mechanism in paper-driving type automatic drafting machine - Google Patents

Abstract

PURPOSE:To smoothly move a pressure roller arm with a small force by biasing a shaft with the eccentric extended part of an eccentric cam to bring a pressure roller into elastic contact with a driving roller and by setting the protruding quantity of the shaft to the roller arm so that the elastic contact force of the shaft to the cam is released when the narrow part of the cam is positioned in the shaft-facing part. CONSTITUTION:When the eccentric extended part of an eccentric cam 58 is moved to a shaft 52 protruding by a predetermined quantity from a pressure roller arm 40 with the force of a spring 56, the shaft 52 is biased by the eccentric extended part, the movement of the pressure roller arm 40 to the eccentric cam 58 is regulated with the frictional force of a friction means working between the shaft 52 and eccentric extended part and a pressure roller 44 is brought into elastic contact with a driving roller 24 by the elastic force of the spring 56. When the eccentric narrow part of the eccentric cam 58 is moved to the shaft 52, the biasing force of the eccentric cam 58 to the shaft 52 is released and the shaft 52 abuts lightly on the eccentric narrow part of the eccentric cam 58 by a torque due to the dead load of the pressure roller arm 40.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pressure roller support mechanism in a paper-driven automatic drafting machine.

[Conventional technology]

Conventionally, this type of pressure roller support mechanism, as shown in FIG. In the figure, the pressure roller 8 is biased clockwise and is brought into elastic contact with the drive roller 10 by the elasticity of the tension spring 6. When the pressure roller 8 is raised from the drive roller 10 in order to insert and arrange the paper between the drive roller 10 and the pressure roller 8, the eccentric cam 12 is rotated and the eccentric enlarged portion 12a moves the pressure roller The upper surface of the arm 2 on the side opposite to the mounting side of the pressure roller 8 is pressed against the elasticity of the tension spring 6, and this pressing force causes the pressure roller arm 8 to
In the figure, the fifth
As shown in Figure (B), the pressure roller 8 is
It is increasing against.

[Problems to be Solved by the Invention] In the above configuration, when the pressure roller rises, a large frictional force is generated between the four pressure roller arms and the eccentric cam due to the spring force, and when the drawing machine is not driven, There was a problem in that an excessive load was always applied to the eccentric cam, which deteriorated the durability of the eccentric cam, and when the pressure roller arm was moved along the shaft, it could not be moved smoothly with a light force.

The present invention aims to eliminate the above-mentioned defects.

[Means to solve problems]

In order to achieve the above object, the present invention supports a pressure roller arm 40 rotatably on a shaft body 36 and movably along the shaft body 36, and a pressure roller 44 is mounted on one side of the pressure roller arm 40. is rotatably supported, and the pressure roller arm 4
0, a shaft 52 that can be slid freely relative to this is connected to a spring 5.
The elastic cam 58 protrudes by a predetermined amount due to the elastic force of the shaft 52, and the eccentric enlarged portion of the long eccentric cam 58 facing the shaft 52 causes the shaft 5 to protrude by a predetermined amount.
2 is pressed against the elastic force of the spring 56, and the pressing force causes the pressure roller 44 to come into elastic contact with the drive roller 24 disposed below the pressure roller 44, thereby reducing the eccentricity of the eccentric cam 58. The pressure roller of the shaft 52 is arranged so that when the pinching portion is positioned opposite to the shaft 52, the elastic contact force on the eccentric cam 58 due to the elastic force of the spring 56 of the shaft 52 is released. Set the amount of protrusion for the arm 40.

The weight balance of the pressure roller arm 40 is such that the side that is not closer to the pressure roller 44 than the center of rotation is heavier.

When the pushing force on the shaft 52 is released.

The pressure roller arm 40 is configured so that the pressure roller 44 swings under its own weight in a direction in which the pressure roller 44 moves away from the drive roller 24, and the pressure roller arm 40 is configured to swing by its own weight in a direction in which the pressure roller 44 moves away from the drive roller 24, and is connected to the eccentric enlarged portion of the eccentric cam 58 and the eccentric cam 58 of the shaft 52. A friction means is provided on at least one side of the abutting portion.

[Effect]

When the eccentric bulge of the eccentric cam 58 is moved by the force of the spring 56 to the shaft 52 that protrudes from the pressure roller arm 40 by a predetermined amount, the shaft 52 is pressed by the eccentric bulge, and the gap between the shaft 52 and the eccentric bulge is The movement of the pressure roller arm 40 relative to the eccentric cam 58 is restricted by the frictional force of the friction means acting on the drive roller 24 , and the pressure roller 44 comes into elastic contact with the drive roller 24 by the elasticity of the spring 56 . When the eccentric pinching portion of the eccentric cam 58 is moved to the shaft 52, the pressing force of the eccentric cam 58 against the shaft 52 is released, and the pressure roller arm 40
The pressure roller 44 swings around the shaft body 36 in the direction of rising from the drive roller 24 due to its own weight, and the shaft 52
Due to the rotational force of the pressure roller arm 40 due to its own weight, the pressure roller arm 40 lightly contacts the eccentric pinched portion of the eccentric cam 58 .

〔Example〕

The structure of the present invention will be described in detail below with reference to embodiments shown in the accompanying drawings.

Reference numeral 14 denotes a paper mounting member of a paper-driven automatic drafting machine, and in FIG. drive shafts 20, 22 are arranged, one drive shaft 20 has a
A long drive roller 24 is fixed to the other drive shaft 22.
A drawing aperture 26 is fixed to. The drive roller 2
4 and the drawing roller 26 are constructed to have approximately the same diameter and are configured to be rotationally driven by an X motor in the same direction at approximately the same circumferential speed during one drawing. Above the paper placement member 14,
In Figure 2, the Y rail (not shown) is shown along the vertical direction of the paper.
is constructed, and a printing head 28 is attached to the Y rail so as to be movable along the Y rail. Belt pulleys are rotatably arranged at both ends of the Y rail, an endless head moving belt 3o is passed around the belt pulleys, and the printing head 28 is connected to the belt 3o. One of the belt pulleys is connected to the output shaft of a Y motor, and when the Y motor is driven, the belt 30 rotates, and as a result of the rotation of the belt 30, 1
The printing head 28 is configured to move along the Y rail. A pen holder 32 disposed on the drawing head 28 in connection with an elevating drive device holds a writing instrument 34 in a detachable manner. 36 is a shaft installed parallel to the Y rail, and a pair of pressure roller arms 3 are attached to this.
The middle part of 8.40 is rotatably fitted. One pressure roller arm 38 is rotatably supported at a fixed position with respect to the shaft 36 so as not to move in the axial direction, and the other pressure roller arm 40 is movable in parallel along the shaft 36. It is freely fitted into the shaft body 36 via a slide ball bearing (not shown). the pressure roller arm 38;
Pressure rollers 42 and 44 are rotatably supported on one of the pressure roller arms 38 and 40, and weights 46 and 48 are fixed to the other of the pressure roller arms 38 and 40, respectively.

A recessed portion for inserting a spring is formed on the lower surface near each other end of the pressure roller arm 38, 40, and a hole 50 is provided at the center of the portion where the recessed portion is formed. A shaft 52 is slidably inserted into the hole 50,
The head 52a of the shaft 52 is connected to the pressure roller arm 38.40.
is placed on the top surface. A flanged cylinder 54 is fixed to the lower end of the shaft 52. Around the shaft 52,
The upper surface of the collar of the cylinder 54 and the pressure roller arm 38.40
A coil spring 56 is inserted and compressed between the lower surface of the coil spring 56 and the lower surface of the coil spring 56 . The lower surface of the head 52a of the shaft 52 is brought into elastic contact with the upper surface of the pressure roller arms 38, 40 due to the elastic force of the coil spring 56, and the shaft 52 is moved by a predetermined amount to the pressure roller arm 38 due to the elastic force of the spring 56. .40
stands out from In FIG. 2, reference numeral 58 denotes an eccentric cam in the form of a long and thin rod suspended in the direction perpendicular to the plane of the drawing. It is connected to the output shaft of a motor 64 via a wheel 62. The eccentric cam 58 includes:
A third eccentric surface (■) for pressing the pressure rollers 42, 44 against the drive roller 24 by the force of the spring 56, and the pressure rollers 42, 44 are pushed away from the drive roller 24 by the weight of the pressure roller arm 38, 40. A second eccentric surface (2) for slightly separating the pressure rollers 42 and 44 and a third eccentric surface for raising the pressure rollers 42 and 44 to the highest position by rotation of the pressure roller arms 38 and 40 under their own weight are formed. There is. The third eccentric surface (2) has a sandpaper-like friction surface processed over its entire length, and a friction means 66 made of the sandpaper-like friction surface is provided on the third eccentric surface (2). . The friction means 66 may be constructed by adhering sandpaper to the eccentric surface (2). Note that the cam shape of the eccentric cam 58 is not particularly limited to the shape shown in FIG. and a second roller for bringing the pressure roller into contact with the drive roller with a small elastic contact force.
It is also possible to form a third eccentric surface for bringing the pressure roller into contact with the drive roller with a large elastic contact force.

Next, the operation of this embodiment will be explained.

When the motor 64 is driven and the eccentric cam 58 is rotated to move the third eccentric surface (2) toward the flanged cylinder 54, the third eccentric surface (2) is applied before it reaches the cylinder 54. The pressure roller arm 38.40 is connected to the eccentric cam 58 via the cylinder 54.
The pressure roller arms 38 and 40 swing clockwise about the shaft body 36 in FIG. come into contact with Moreover, when the eccentric cam 58 rotates and the eccentric surface (2) in FIG. 2 approaches the cylinder 54, the cylinder 54 is pushed up by the cam surface in front of the third eccentric surface (2). At this time, the pressure rollers 42 and 44 are pressed against the drive roller 2.
Since the pressure roller arm 38.4 is already in contact with the
0, clockwise rotation is blocked. Therefore, the cylindrical body 54 is pushed up against the elastic force of the spring 56, the shaft 52 rises along the hole 50, and the spring 56 is placed between the pressure roller 42, 44 and the drive roller 24. Pressure is applied according to the compressive elastic force. Eccentric cam 58
When the third eccentric surface (2) is located directly below the cylinder 54, the pressure rollers 42, 44 come into elastic contact with the drive roller 24 with a predetermined pressure due to the compressive elasticity of the spring 56. This state is illustrated by A in FIG. In this state, a large friction force is exerted by the friction means 66 between the eccentric surface (1) and the cylindrical body 54, and this friction force causes the displacement of the pressure roller arm 4Q in the direction along the shaft body 36. Prevented. When the eccentric cam 58 is further rotated and the second eccentric surface ■ is moved toward the cylinder 54, the second eccentric surface ■ is moved toward the cylinder 54.
Drive roller 24 of pressure roller 42, 44 before reaching
The elastic contact force against the shaft 52 is released, and the head 52a of the shaft 52 changes from the state in which it protrudes from the upper surface of the pressure roller arm 38.40, to the state where the lower surface of the head 52a touches the pressure roller arm 38.40.
The cylinder body 54 comes into elastic contact with the upper surface of the eccentric cam 58 due to the force of the spring 56, and the cylindrical body 54 comes into contact with the cam surface of the eccentric cam 58 not due to the force of the spring 56 but due to the weight of the weights 46 and 48. Moreover, the eccentric cam 58 rotates, and the second eccentric surface
When the cylinder 54 reaches this point, the weight of the weight 48 causes the cylindrical body 54 to descend as the eccentricity of the eccentric cam 58 decreases, and the pressure rollers 42 and 44 move toward the drive roller as shown by B in FIG. It rises slightly from 24 (normally up position). When the eccentric cam 58 is further rotated and the first eccentric surface (■) is moved directly below the cylindrical body 54, as the eccentricity of the eccentric cam 58 decreases,
The pressure roller arm 38.40 swings counterclockwise in FIG. 2 with the shaft body 36 as the center due to the weight of the weight 46.48, and the pressure rollers 42, 44 move as shown at C in FIG. Raise to the highest position shown. In this state, the pressure roller arm 40 is positioned on the line of movement of the moving engagement body 60 provided on the printing head 28. With the pressure rollers 42 and 44 raised to their highest positions, paper is set on the paper placement member 14, and the paper is placed between the drive roller 24 and the pressure rollers 42 and 4.
Place it between 4. In this state, when the printing head 28 is driven along the Y rail and the pressure roller arm 40 is pressed via the moving engagement body 60 by the movement of the printing head 28, the pressure roller arm 40 is moved along the axis. moving along the body 36;
The pressure roller 44 held by the pressure roller arm 40 is moved to the optimal position on the groove 16 according to the size of the paper, and the fixed position pressure roller arm 38 and the moving pressure roller arm 4 are moved.
The distance from 0 can be adjusted. When the pressure roller arm 40 moves along the shaft body 36, the cylinder body 54 is only in contact with the eccentric cam 58 due to the weight of the weight 48, so there is no space between the cylinder body 54 and the eccentric cam 58. No large frictional force acts. Note that the rotation of the eccentric cam 58 and the movement of the pressure roller arm 40 along the shaft body 36 are not particularly limited to automatic operation, and may be operated manually. It may be provided only on the eccentric surface (1) or on both the eccentric surface (1) and the lower surface of the cylindrical body 54. In addition, as shown in FIGS. 3 and 4, the eccentric cam 5
A rack 80 is provided over the entire length on the eccentric surface (■) of the cylinder 70, and a rack 72 is provided on the lower surface of the cylinder 70.
．． 72 may constitute a friction means.

〔effect〕

As described above, when the pressure roller arm is raised, a large frictional force does not act between the pressure roller arm and the eccentric cam that raises it, so pressure can be applied smoothly with a small moving force. The roller arm can be moved along its rotation center axis, and when the pressure roller comes into elastic contact with the drive roller, the pressure roller arm is securely fixed to the eccentric cam by the friction means, so that the pressure roller arm is securely fixed to the eccentric cam during drawing. Pressure 6-
There are effects such as preventing the rear arm from shifting in the lateral direction.

[Brief explanation of drawings]

FIG. 1 is an explanatory view of the external appearance, FIG. 2 is an explanatory side view, FIG. 3 is an external view showing another embodiment, FIG. 4 is a side view of the same, and FIG. 5 is an explanatory view of the prior art. 2... Pressure roller arm, 4... Shaft body, 6... Spring, 8... Pressure roller, 1o... Drive roller, 12... Eccentric cam, 14... Paper placement Member, 16.
18...Groove, 20.22...Drive shaft, 24...Drive roller, 26...Drawing roller, 28...Printing head, 30...Belt, 32...Pen holder, 34...
... Writing instrument, 36 ... Shaft body, 38.40 ... Pressure roller arm, 42.44 ... Pressure roller, 46.48
... Weight, 50 ... Hole, 52 ... Shaft, 52a
... Head, 54 ... Cylindrical body, 56 ... Coil spring, 58 ... Eccentric cam, 60 ... Engagement body, 66 ...
...Friction means.

Claims (3)

[Claims] (1) A pressure roller arm 40 is rotatably supported on a shaft 36 and movable along the shaft 36, and a pressure roller 44 is rotatably supported on one side of the pressure roller arm 40;
A shaft 52 that is slidable relative to the pressure roller arm 40 is projected by a predetermined amount by the elastic force of a spring 56, and the shaft 52 is moved by an eccentric enlarged portion of a long eccentric cam 58 disposed opposite to the shaft 52. is pressed against the elastic force of the spring 56, and due to the pressing force, the pressure roller 4
4 is configured to come into elastic contact with the drive roller 24 disposed below the eccentric cam 58, and the eccentric pinched portion of the eccentric cam 58 is connected to the shaft 52.
When the spring 5 of the shaft 52 is positioned opposite to the
The pressure roller arm 4 of the shaft 52 is arranged so that the elastic contact force against the eccentric cam 58 due to the elastic force of the shaft 52 is released.
The amount of protrusion relative to 0 is set, and the pressure roller arm 40
The weight balance is made heavier on the side that is not closer to the pressure roller 44 than the center of rotation, and when the pushing up force against the shaft 52 is released, the pressure roller arm 40 moves toward the pressure roller 44.
is configured to swing in a direction away from the drive roller 24 due to its own weight, and a friction means is provided on at least one side of the eccentric enlarged portion of the eccentric cam 58 and the portion of the shaft 52 that abuts the eccentric cam 58. A pressure roller support mechanism in a paper-driven automatic drafting machine, characterized by: (2) The pressure roller support mechanism in a paper-driven automatic drafting machine according to item 1, characterized in that a friction means is provided on the eccentric enlarged portion of the eccentric cam 58. (3) In the paper-driven automatic drafting machine according to item 1, a friction means is provided on both the eccentric enlarged portion of the eccentric cam 58 and the portion of the shaft 52 that comes into contact with the eccentric cam 58. Pressure roller support mechanism.