JPS6224535Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a mechanism for attaching and detaching printing paper to a paper slack prevention device in a printing device such as a typewriter.

Some printing devices are designed to apply tension to the paper using a paper presser such as a roller to prevent the attached paper from becoming loose, but all of these devices must be opened and closed manually. It was a hassle.

The present invention aims to eliminate such inconvenience and facilitate the attachment and detachment of paper to the paper slack prevention device.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 shows a letter type printer that employs the opening/closing mechanism of this invention.

Reference numeral 1 denotes a cylindrical type drum, which rotates itself and reciprocates between the left and right side plates 2, 2. A paper guide 3 having an arch-shaped cross section is positioned above the type drum 1 to cover it. The printing paper 4 is placed on the paper guide 3, and its upper end is fixed by a clamp device 5, and its lower free end is clamped by a roller-shaped paper presser 6 and a plate-shaped pressing member 7. 8
is a carriage, which is slidably installed between two guide shafts 9 and 10, and
A pair of reels 13, 13 on which a printing hammer 11 and an ink ribbon 12 are wound are attached. 1
4 is a hammer positioning wire, which is connected to the carriage 8 via a number of pulleys 15, 16, 17, 18, and 19. 20 is a hammer positioning motor for moving the wire 14.

FIG. 2 schematically shows a paper feeding mechanism, in which an internal gear 22 rotates as an external gear 21 rotates by a motor (not shown), and a clamp device 5 connected to this rotates as a paper guide. Slide the top surface of 3 one pitch at a time in the clockwise direction in the figure. The printing hammer 11 is inserted into the gap 2 between the paper guide 3 and the pressure contact member 7.
It is located in front of the printer 3 and is designed to print by striking the printing paper 4 against the character drum 1 via the ink ribbon 12.

The loosening prevention device will be explained with reference to FIGS. 1 and 3. It consists of a paper presser 6 that is swung open and closed by the opening/closing mechanism 24 of the present invention, a plate-shaped press member 7 that presses against the paper presser 6, and a carriage 8. It basically consists of a transmission mechanism 25 that transmits the horizontal movement of the paper presser 6 to the paper presser 6 as rotational motion.

One end of the long-axis roller-shaped paper presser 6 is rotatably connected to the upper end of an opening/closing mechanism 24, which will be described later, and the other end is connected to a transmission mechanism 25 via a swing pulley 26.

The pressure contact member 7 is made of a metal plate with a smooth surface, and is located directly under the front end of the paper guide 3, and has a paper presser 6 at approximately the center of a support rod 27 installed between the side plates 2, 2.
It is erected facing the.

The transmission mechanism 25 includes two belts 2 between the pulley 15 and a conversion pulley 28 located behind the pulley 15.
9 and 30 are wrapped around each other, one is an open type and the other is a closed type, and the conversion pulley 28 is equipped with an automatic switching clutch, so that the forward and reverse rotation of the pulley 15 can be changed to one direction (direction of arrow A). This is converted and transmitted to the paper presser 6. Here, a support pulley 32 is attached to the tip of the shaft 31 of the conversion pulley 28.
A swing pulley 26 is rotatably connected above the support pulley 32 by an arm 33, and the rotation of the conversion pulley 28 is caused by swinging from the support pulley 32 via a belt 34. The signal is transmitted to the dynamic pulley 26.

Next, the opening/closing mechanism of the present invention will be explained with reference to FIGS. 4 and 5. Reference numeral 35 denotes a rotating rod that rotatably supports the paper presser 6 at its upper end and has a round bar-shaped pressing portion 36 of a certain length at its lower end. This rotating rod 35 has its central portion pivotally supported by a shaft 38 on a support plate 37 fixed to the support rod 27, and one end of the upper portion is pulled up by a spring 40 from a post 39 protruding from the support rod 27. energized. Here, the shaft 38 is coaxial with the shaft 31 in the transmission mechanism 25, and the paper presser 6 swings back and forth at a constant angle about both shafts 38, 31 as axes. Rectangular rotating plate 4 located below the rotating rod 35
1 has an abutment piece 42 rising up from its tip, a pressure roller 43 is pivotally attached to the upper surface of the central portion, and the entire body is pivotably supported on the lower surface of the support rod 27 so as to be horizontally rotatable.

Regarding the operation of the opening/closing mechanism of the present invention constructed as described above, the carriage 8 moves rightward in the figure by the electric control pulse accompanying the completion of the printing operation and comes into contact with the contact piece 42 of the rotating plate 41. , press this. Then, the rotating plate 41 rotates and presses the pressure roller 4.
3 presses the pressing portion 36, the rotating rod 35 rotates against the force of the spring 40, and the paper presser 6 separates from the pressing member 7.

When a new printing paper 4 is loaded and its lower end is slipped between the paper presser 6 and the pressure contact member 7 to start printing, the carriage 8 returns to the printing position, leaves the opening/closing mechanism 24, and moves to the rotating rod 35. is rotated again to the original position by the force of the spring 40, presses the paper presser 6 toward the pressing member 7, and clamps the paper 4.

Regarding the function of the loosening prevention device, each time the printing hammer 11 operates to print one character, the amount of movement of the carriage 8 is changed from the pulley 15 to the transmission mechanism 25.
is transmitted to the paper presser 6 as an intermittent rotational motion. At this time, the pulley 15 rotates in both forward and reverse directions depending on the direction of movement of the carriage 8, but the belts 29, 30 and the automatic switching clutch in the conversion pulley 28 cause the paper presser 6 to rotate in one direction, that is, in the direction of the pressure contact member 7. The paper 4 is rotated only in the direction of pulling down the paper 4 that is clamped therebetween, thereby preventing the paper 4 from becoming loose.

In the above example, the carriage 8 indirectly contacts and presses the pressing portion 36 of the rotating rod 35 through the rotating plate 41, but this can be changed as shown in another embodiment shown in FIG. , the carriage 8 is directly connected to the rotating rod 35.
It may be constructed so that it comes into contact with the pressing part of the holder and rotates it. That is, in FIG. 6, the pressing part 36 is a plate-like member with a slope 44 formed at one end, and at a position near the pressure contact member 7 on the upper surface of the pressing part 36,
A weight 45 of a constant weight is fixedly attached. According to this, during the printing operation, the pressing portion 36 is at the lowest position due to the gravity of the weight 45, and therefore the paper presser 6 is pressed toward the pressing member 7 side. When printing is completed and the carriage 8 moves and comes into contact with the slope 44 of the pressing part 36, this acts as a cam and rotates the rotating rod, pulling the paper presser 6 away from the pressing member 7 and releasing the paper 4. release.

As explained above, according to the opening/closing mechanism of the present invention, the free end of the paper is automatically released at the end of the printing operation, and is clamped at the same time as the printing operation starts.
There is no need to do this manually as in the past,
Paper can now be attached and detached extremely easily, quickly and reliably.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway perspective view of a dial type printer that adopts the opening/closing mechanism of this invention, Fig. 2 is a sectional view schematically showing its paper feeding mechanism, and Fig. 3 is a front view showing the main parts of the paper slack prevention device. 4 is a perspective view of the opening/closing mechanism of the present invention, FIG. 5 is a sectional view taken along the line BB in FIG. 3, and FIG. 6 is a perspective view showing another embodiment of the opening/closing mechanism of the present invention. DESCRIPTION OF SYMBOLS 1... Type drum, 2, 2... Side plate, 3... Paper guide, 4... Print paper, 5... Clamp device, 6... Paper presser, 7... Pressing member, 8... Carriage, 11... ... Printing hammer, 14 ... Hammer positioning wire, 20 ... Hammer positioning motor, 24 ... Opening/closing mechanism, 25 ... Transmission mechanism, 2
6... Swing pulley, 28... Conversion pulley, 35...
...Rotating rod, 36...Pushing part.

Claims (1)

[Scope of utility model registration request] In a paper slack prevention device for a printing device that applies tension to the paper by pressing a paper presser against the free end side of the printing paper, there is a circuit in which the paper presser is connected to one end and a pressing part is provided at the other end. A method for preventing paper slack in a printing device, characterized in that a moving rod is pivoted on the printing device side, and when a carriage comes into contact with the pressing portion, the rotating rod rotates so as to move a paper presser away from the printing paper. Opening/closing mechanism of the device.