JPH07121640B2 - Pinch roll assembly structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a plotter or the like in which sheets are sandwiched between a driving wheel and a pinch roll, which are vertically opposed to each other in a state of being urged to move the sheet. The present invention relates to a pinch roll assembly structure used in.

[Prior Art] In general, a paper move type plotter is constructed by pinching rolls provided on the upper side of driving wheels provided on the drawing bed so as to be opposed to each other. By placing the paper on the top and moving the pinch roll downward, the paper is pinched by the drive wheel and the pinch roll. Then, by rotating the drive wheels in this state, the above-mentioned paper is moved on the drawing bed. In this case, the vertical movement of the pinch roll is as shown in FIG. 6 and FIG. 7 or 8.
This is performed as shown in the figure and FIG. That is, in the method shown in FIG. 6 and FIG. 7, the pinch roll 1 is axially supported by the tip end of the support part 3 whose center part is rotatably supported by the support shaft 2, and the support part The rear end of the lever 3 is engaged with the front end of the lever 5 that slides between the guides 4. Therefore, by moving the grip portion 5a of the lever 5 in the direction of arrow a in FIG. 6, the pinch roll 1 is biased toward the drive wheel 6 side, and the drive wheel 6 and the pinch roll 1 can pinch the paper 7. The pinch roll 1 can be lifted upward and the paper 7 can be released by moving the grip portion 5a in the direction of arrow b in FIG. Further, in the method shown in FIGS. 8 and 9, the pinch roll 1a is pivotally supported at the tip of the support portion 3a whose central portion is supported by the support shaft 2a and whose rear portion is biased upward by the spring body 8. Has been done. A cam catch 9 is provided on the upper surface of the rear end of the support portion 3a. Above the cam catch 9, a cam 10 whose lower end slides on the curved upper surface of the cam catch 9 is centered on the spindle 11. It is provided in a freely rotatable state. The pinch roll 1a is
By moving the upper end of the cam 10 in the direction of arrow c in FIG. 8, the cam 7 can be urged toward the drive wheel 6 side, thereby nipping the sheet 7 with the drive wheel 6, and in the direction of arrow d in FIG. By moving the upper end of the cam 10, the paper 7 is moved upward and the paper 7 is released.

[Problems to be Solved by the Invention] However, in the method shown in FIGS. 6 and 7 among the above methods, the stop position of the pinch roll 1 changes depending on the moving distance of the lever 5, so that the pinch roll 1 stops. There is a problem in that the position is unlikely to be constant and the pressing force of the pinch roll 1 against the drive wheel 6 tends to be uneven. In the method shown in FIGS. 8 and 9, when the cam 10 is moved, There is a problem that the hand is slippery and the reaction force causes the cam 10 to rotate vigorously in the direction opposite to the operation direction, which is dangerous. Further, both have a problem that they are difficult to operate.

The present invention has been made in view of the above circumstances, and provides a pinch roll assembly structure that is easy to operate, can keep the pressing force of the pinch roll against the drive wheel constant, and is not dangerous. To that end.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention rotatably attaches a front end side of a support portion having a pinch roll axially supported to a horizontal support shaft, and a rear end portion thereof. A pinch roll assembly structure in which the pinch roll is vertically positioned by moving it vertically, and a rear side of the support part is urged upward by a first spring body, A notch opening vertically is provided on the rear side, and a shaft is bridged over both left and right walls of this notch, and a pressed portion is formed on the peripheral surface on one end side of this shaft and a circular shape is formed on the other end surface. A ratchet on which an engaging projection having an inclined surface at one end along the other is projected is loosely fitted, and at the other end, an engaged portion capable of meshing with the engaging projection is provided on one end surface, and the ratchet is provided on the upper portion. A cam having a locking piece protrudingly fits loosely with the second spring body urging the cam toward one end. A pressing portion is provided below the pressed portion of the ratchet, and a stopper having a convex portion abutting the upper end of the locking piece and a concave portion into which the locking piece can be fitted is provided above the locking piece of the cam. When the ratchet and the cam are engaged with each other, the locking piece of the cam and the convex portion of the stopper are placed in a state in which the rear side of the support portion is positioned downward against the first spring body. If the rear end side of the supporting portion is further pressed downward against the first spring body while being pressed, the locking piece of the cam and the convex portion of the stopper are released from the pressed state and the pressed portion is pressed. Part contacts the pressing part, the ratchet rotates, and the cam is pushed toward the other end side of the shaft body so as to ride on the inclined surface of the engagement projection of the ratchet, and in that state, the lower part of the rear end side of the support part is lowered. When the pressure on the cam is released, the locking piece of the cam will When the rear end side of the supporting portion moves upward to position the pinch roll downward, and when the rear end side of the supporting portion is pressed downward again, the pressed portion comes into contact with the pressing portion and the ratchet rotates. The cam is engaged with the cam so that the locking piece of the cam and the convex portion of the stopper are in pressure contact with each other to position the pinch roll upward.

[Operation] That is, the assembly structure of the pinch roll according to the present invention is
The rear side of the support portion that pivotally supports the pinch roll is urged upward by the first spring body, and the shaft body is bridged in the cutout portion provided on the rear side of the support portion. When the teeth engage with each other, the ratchet and the cam are loosely fitted in a state in which the ratchet and the cam are urged by the second spring body. A pressing portion is provided below the ratchet, and the ratchet is rotated by pressing the pressed portion of the ratchet against the pressing portion, and the cam is applied to the other end side of the shaft body against the second spring body. I am able to move it. A stopper having a convex portion and a concave portion is provided above the cam, and when the ratchet and the cam mesh with each other, the convex portion of the stopper is provided above the cam against the first spring body. It engages with the locking piece by pressure contact, so that the rear part side of the support part is positioned downward, and when the cam moves to the other end side of the shaft body and the meshing of the ratchet and the cam is released. The locking piece is fitted in the recess of the stopper so that the rear side of the support portion moves upward. Therefore, when the locking piece of the cam is engaged with the convex portion of the stopper and the pinch roll is positioned upward, the rear end side of the support portion is further pressed downward against the elastic force of the first spring body. The ratchet moves downward together with the rear end side of the support portion, and the pressed portion abuts on the pressing portion to rotate the ratchet. By this rotation, the cam rides on the inclined surface of the engagement projection of the ratchet and is pushed toward the other end of the shaft, and as a result, the engagement between the locking piece of the cam and the convex portion of the stopper is released. The locking piece is fitted in the recess of the stopper, and the rear end side of the support portion is biased upward by the first spring body so that the pinch roll is positioned downward. Further, when the rear end side of the support portion is pressed downward again, the pressed portion of the ratchet comes into contact with the pressing portion, the ratchet rotates, and the ratchet and the cam mesh with each other. As a result, the locking piece of the cam engages with the convex portion of the stopper, and the pinch roll is positioned upward. In this way, the pinch roll can be positioned downward by pressing the rear end side of the support portion downward while the pinch roll is positioned above, and the pinch roll can be further pressed by pressing the rear end portion of the support portion. Thus, the stop position of the pinch roll can be changed up and down simply by repeatedly pressing the rear end portion of the support portion so that the pinch roll can be positioned upward. Further, in this case, the upper and lower stop positions of the pinch roll are always constant due to the engagement of the upper surface of the support portion with the engagement portion and the engagement of the cam engagement piece with the protrusion of the stopper. Therefore, there is no unevenness in the pressing force of the pinch roll against the drive wheel.
Next, the present invention will be described in detail based on examples.

[Embodiment] FIGS. 1 and 2 show an embodiment of the present invention. That is, in the figure, 13a and 13b are a pair of plate-like frames that face each other with a constant spacing, and a stopper 14 is fixed between the upper parts of the rear ends of the two, and fixing rods 15a, 15a, respectively on the upper and lower parts on the front end side. It is fixed with the 15b bridged. Between the frames 13a and 13b, a support portion 17 having a pinch roll 16 pivotally supported at its tip is attached rotatably around a support shaft 18, and a grip connected to the rear end portion of the support portion 17 is provided. By pressing the portion 17a downward, the pinch roll 1
The stop position of 6 can be changed up and down. To explain this in more detail, the support portion 17 is
As shown in FIG. 3, the rear side is formed by a plate-like body that is bent so as to gradually rise upward, and a square notch 19 is provided on the rear side. Reference numeral 20 denotes a rod-shaped shaft body, one end side of which is inserted through the center hole of the ratchet 21 and the other end side of which is inserted through the center hole of the cam 22, and both end portions are fixing holes formed on both left and right walls of the cutout portion 19. It is fixed to 20a and 20b. The ratchet 21 is formed in a disc shape with one end having a small diameter and the other end having a large diameter, and a locking tooth portion 23 is engraved on the peripheral surface of the small diameter portion, and the other end surface of the large diameter portion, Four engaging projections 24 are provided at regular intervals along the circumference, the tip end surface of which is inclined upward in the direction along the circumference (clockwise direction when viewed from the other end). The cam 22 has an engaged projection 25 that meshes with the engaging projection 24 of the ratchet 21 on one end surface of the cylindrical body.
And three locking pieces 26 are planted on the upper part of the main body at regular intervals along the axial direction. Reference numeral 27 is a spring body that is attached to the outer periphery of the other end of the shaft body 20 and presses and biases the cam 22 toward the ratchet 21 side. On the other end surface of the cam 22, an engaging piece (not visible hidden in the figure) that engages with the upper surface of the support portion 17 is provided so as to rotate about the shaft body 22 of the cam 22. The cam 22 can be moved only along the axial direction of the shaft body 20. Further, 28 is a shaft to which a substantially L-shaped hook 29 is fixed at one end side, and a locking piece 29a of the hook 29 is locked to the lower surface of the support part 17 and a claw part 29b is fitted to the tooth part 23 of the ratchet 21. In the engaged state, it is fixed to the rear end side of the cutout portion 19. Therefore, the ratchet 21 can rotate about the shaft body 20 only in a fixed direction (clockwise direction when viewed from one end side). Reference numeral 30 is a shaft for engaging the spring body, both ends of which are fixed to holes 31a and 31b provided at substantially the center of the supporting portion 17, and both sides of the shaft 30 have spring bodies (see FIGS. 1 and 2). (See the figure) The lower end of 32 is adapted to be engaged. The upper end portion of the spring body 32 is engaged with a shaft 33 that is bridged over the upper end substantially central portion of the frames 13a, 13b, and the elasticity of the spring body 32 causes the rear side of the support portion 17 to be urged upward. Has become. Also, the stopper
As shown in FIG. 3, 14 is constituted by vertically arranging a plate-shaped rear wall 14b at the rear end of a main body 14a having a shape obtained by dividing a cylindrical body into quarters along the axis. Three slide grooves 14c are formed on the shaft side so as to draw a circle around the shaft at regular intervals along the shaft. The slide groove 14c is provided with a width and an interval at which the locking piece 26 of the cam 22 can be inserted and internally fitted, and when the cam 22 is positioned on the other end side of the shaft body 20, the cam 22
It is adapted to engage with the locking piece 26 of. Therefore,
The rear end side of the support portion 17 is pressed downward, and the elastic force of the spring body 27 moves the cam 22 to the one end side of the shaft body 20 so that the engaged projection 25 of the cam 22 engages with the engagement projection 24 of the ratchet 21. If the pressure on the rear end side of the support portion 17 is released in this state, the cam 22
The upper end surface of the locking piece 26 comes into contact with the lower surface of the main body 14a of the stopper 14, and the rear end side of the support portion 17 remains in the lower position. When the locking piece 26 of the cam 22 and the slide groove 14c of the stopper 14 are engaged with each other, the rear side of the support portion 17 is biased upward and its upper surface abuts the lower surface of the stopper 14 on the convex side of the main body 14a. This contact causes the support portion 17 to stop with the pinch roll 16 positioned at the lower position. Further, the rear wall 14b of the stopper 14 is inserted through the rear end side of the cutout portion 19 and extends downward. 34 is a frame 13a, 13b
Is a shaft that is bridged to the rear side of the lower end, and a hook 35 having an upper portion formed on a pressing piece 35a is attached to one end side, and the hook 35 is pressed to the one end side of the shaft 34 for biasing the hook 35 on the other end side. A spring 36 is attached. Above hook
Denoted at 35 is a state in which projections 35b and 35c projecting from both ends are engaged with notched recesses 37a and 37b provided at the lower end of the frame 13a to prevent rotation (see FIGS. 4 and 5), and are pressed. Piece 35a
Of the ratchet 21 is directed toward the front side of the tooth portion 23 of the ratchet 21. Therefore, when the rear end side of the support portion 17 is pressed downward, the tooth portion 23 of the ratchet 21 comes into contact with the pressing piece 35a and the ratchet 21 rotates, whereby the cam 22 causes the other end side of the shaft body 20. Pushed to. In FIG. 3, reference numeral 38 is a shaft for supporting the pinch roll 16, and both ends are fixed to shaft holes 39a and 39b formed at the tip of the supporting part 17 to fix the pinch roll 16 to the supporting part 1.
It is designed to be positioned in the notch 40 of 7. Also,
In FIG. 1 and FIG. 2, reference numeral 41 is a slide groove which is provided in an up-down state so as to face each other, engages with a rail portion provided on the plotter, and the assembly of the pinch rolls is fitted along the rail. It is designed to slide.

In this configuration, the pinch roll assembly is provided above the drive wheels on both sides of the plotter.
Two pinch rolls 16 are attached in such a state that the pinch rolls 16 are in pressure contact with the drive wheels when they are positioned below. And
In use, first, the pinch roll 16 is positioned above and the drawing paper is placed on the drive wheel. Then, the grip 17a is pressed downward to press the pinch roll 16 against the paper on the drive wheel, and the paper is nipped and fixed by the drive wheel and the pinch roll 16. Next, in this state, the drive wheel is rotated, and while moving the paper, the pen is moved in a direction orthogonal to the moving direction of the paper, thereby drawing on the paper. After drawing, the drive wheels are stopped and the grip 17a is pressed downward to raise the pinch roll 16 upward. Then, remove the printed paper from the plotter. In the above, the vertical movement operation of the pinch rolls 16 can be performed by operating the two pinch rolls 16 at the same time, or by operating one of them at a time.

As described above, according to the assembling structure of the pinch rolls, the operation of moving the pinch rolls 16 up and down only needs to press the grip portion 17a downward, which is extremely easy. Also, the grip
Since the hand 17p is pressed from above, it is unlikely that the hand slips from the grip 17a, and unlike the conventional example, the recoil of the hand 17a does not cause an injury to the operator. Furthermore, since the pinch roll 16 is positioned at a fixed lower stop position by the contact between the rear upper surface of the support portion 17 and the lower surface of the main body 14a of the stopper 14,
The pressing force of the pinch rolls 16 on the drive wheels is always constant, and stable movement of the paper is performed. As a result, it is possible to perform good and accurate drawing.

EFFECTS OF THE INVENTION As described above, since the pinch roll assembly structure of the present invention is configured, the pinch roll can be moved up and down by a simple operation of pressing the rear end side of the support portion downward. Can be made. Further, since the operation of the grip portion does not push or rotate the grip portion laterally but presses the grip portion downward, it is safe that a hand does not slip from the grip portion. Further, since the stop position of the pinch roll is always constant, there is no unevenness in the pressing force on the drive wheels.

[Brief description of drawings]

FIG. 1 is a perspective view showing a state in which a pinch roll of one embodiment of the present invention is located above, FIG. 2 is a perspective view showing a state in which the pinch roll is located below, and FIG. FIG. 4 is an exploded perspective view, FIG. 4 is a bottom view showing a state in which FIG. 1 is looked up from below, FIG. 5 is a bottom view showing a state in which FIG. 2 is looked up from below, and FIG. 6 is a conventional pinch roll. Is a front view showing a state in which the pinch roll is located below, FIG. 7 is a front view showing a state in which the pinch roll is located above, and FIG. 8 is a front view showing a state in which another conventional pinch roll is located below. FIG. 9 is a front view showing a state in which the pinch roll is located above. 14 …… Stopper, 16 …… Pinch roll, 17 …… Support, 18 …… Spindle, 19 …… Notch, 20 …… Shaft, 21 …… Ratchet, 22 …… Cam, 23 …… Tooth , 24 …… engaging projections,
25: Engaged projection, 26: Locking piece, 27, 32: Spring body, 3
5a …… Pressing piece, 38 …… Axis

Claims (1)

[Claims] 1. A pinch roll is rotatably attached to the tip end side of a support part having a pinch roll pivotally supported at its tip end, and its rear end part is vertically moved to position the pinch roll vertically. A pinch roll assembling structure, wherein a rear side of the support portion is biased upward by a first spring body, and a cutout portion that opens vertically is provided on the rear side of the support portion. The shaft is bridged between the left and right walls of the shaft, and one end of the shaft has a projection on the peripheral surface, and the other end has an engaging protrusion with one end along the circumference and the other end inclined. The ratchet provided is loosely fitted, the other end is provided with an engaged portion capable of meshing with the engaging projection on one end surface, and a cam having a locking piece projecting on the upper portion is formed by the second spring body. It is loosely fitted in a state of being biased toward one end side, and a pressing portion is provided below the pressed portion of the ratchet, Above the locking piece of the cam, there is provided a stopper provided with a convex portion that abuts the upper end portion of the locking piece and a concave portion into which the locking piece can be fitted. When the ratchet and the cam mesh with each other, , The locking piece of the cam and the convex portion of the stopper are pressed against each other with the rear side of the support portion positioned downward against the first spring body, and from that state, the first spring body is resisted. When the rear end side of the support portion is further pressed downward, the pressure contact between the locking piece of the cam and the convex portion of the stopper is released, and the pressed portion comes into contact with the pressing portion to rotate the ratchet, When the cam is pushed toward the other end side of the shaft body so as to climb up the inclined surface of the engaging projection of, and the downward pressing of the rear end side of the support part is released in that state, the locking piece of the cam is released. The rear end side of the support part moves upward and fits the pinch roll downwards by fitting it in the recess of the stopper. When the rear end side of the support portion is pressed downward again after positioning, the pressed portion comes into contact with the pressing portion, the ratchet rotates and meshes with the cam, and the locking piece of the cam and the convex portion of the stopper. The pinch roll assembly structure is characterized in that the pinch rolls are pressed against each other to position the pinch rolls upward.