JPH0143254Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention is a paper edge winding system that is necessary for stabilizing the paper feed of sheet feed tractors used in computer printers, word processors, teletypewriters, etc. This relates to a prevention mechanism.

[Problems with conventional technology and issues to be solved]

As shown in FIG. 5, the sheet feed tractor T that feeds the sheet W in which punch holes h, h, etc. are continuously punched along both side edges is a drive unit disposed parallel to the paper width direction. It is attached to the shaft D and the support shaft S, and the carrying pins P, P,... on the belt B are engaged with the punched holes h, h... on both side edges of the sheet W, so that the paper can be fed. Note that C is a cover plate that guides the sheet W by sandwiching it between the upper surfaces of a pair of guide members 1 and 2 that are disposed opposite to each other with the belt B in between, and punches holes h at the paper side end from the carrying pins P, P... h... is designed to prevent it from detaching (see Figure 6).

In such a sheet feed tractor T, once the edge of the paper passes the front end of the paper feed direction guide members 1 and 2, there is no support, so it is suitable for weak paper such as thin paper. In this case, there is a risk that the edge of the paper will move with the downward movement of the carrying pin P and become entangled, causing printer trouble.

The object of the present invention is to provide a sheet-feed tractor that does not cause the edges of paper to get caught even when the paper is thin or subjected to some kind of wind pressure.

[Means to achieve the purpose]

As shown in FIG. 1, the present invention consists of a pair of guide members 1,
A sub-guide member 3 is fixed to the front end of the guide members 1 and 2 with fixed feet 31 and 31 that are fitted in between the guide members 1 and 2, and are engaged with the carrying pins P and P to the upper surface of the guide members 1 and 2. Even after the front end of the sheet W being guided and transported forward is separated from the carrying pin P, the upper surface of the extension guide surface 32 is guided to prevent the front end of the sheet from being caught.

The sheet-feed tractor shown in FIG. 1 includes a pair of cover plates C ₁ and C ₂ .
That is, as shown in FIGS. 3a and 3b, the sub-guide member 3 has an arc-shaped cross section so as to come into contact with the slightly curved and bulging front ends of the guide members 1 and 2, and extends from the approximately central position thereof. A pair of protruding fixed legs 31, 3
I have 1. A pair of fixed feet 31, 31 is inserted between the guide members 1, 2, and the side portions 31a, 31a are provided on the outside of the fixed foot 31, which protrudes outward. Corresponding holes 1 bored inside the front ends of the guide members 1 and 2
1 and 21, the sub-guide member 3 is fixed (see FIG. 4).

When the sub-guide member 3 is fixed to the front ends of the guide members 1 and 2, as shown in FIG.
Since the extended guide surface 32 of the sub-guide member 3 extends as if the guide members 1 and 2 are extended,
The front end of the sheet W that has passed the front end of is guided by the guide surface 32.

Note that if a similar guide groove 32a is provided in the guide surface 32 so as to extend the guide groove 22a provided in the guide surface 22 of the guide member 2, the guiding performance during sheet feeding will be further improved.

[Effect of idea]

As explained above, according to the present invention, the sub-guide member 3 is attached to the front end of the guide member to guide the front end of the sheet, which is likely to cause curling, even after the carrying pin is detached, so that the curling of the paper edge does not occur at all. Therefore, stable paper feeding is achieved.

Further, the sub-guide member 3 has its fixed legs 31,
31 can be inserted into the gap between the guide members and fixed, resulting in a compact structure, and the sheet feed tractor can be hardly bulky.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view of the members constituting the paper edge entanglement prevention mechanism of the present invention, Fig. 2 is a perspective view showing the main parts thereof, and Fig. 3 is an inner front view a and a side view showing an example of the sub-guide member. In the side view b, FIG. 4 is a cross-sectional view taken along the - line in FIG. 3 a, FIG. 5 is a perspective view for explaining the operation of a conventional sheet-feed tractor, and FIG. It is a diagram. 1, 2...Guide member, 3...Sub guide member, 3
1...Fixed foot, 32...Guide surface, B...Carring belt, P...Carring pin, T...Sheet feed tractor, h...Punch hole.

Claims (1)

[Scope of claim for utility model registration] Punch holes h,
In a sheet feed tractor T that feeds a sheet W having perforations h..., a sub-guide member 3 is attached to the front end of a pair of guide members 1 and 2 that are disposed opposite to each other with a carrying belt B in between. The front end of the sheet W is fixed via fixing feet 31 and 31 which are fitted between the guide members 1 and 2, and is engaged with the pin P of the carrying belt B to be guided to the upper surface of the guide members 1 and 2 and transported forward. A paper edge entanglement prevention mechanism characterized in that the carrying belt B is guided by the extended guide surface 32 of the sub-guide member 3 after it is separated from the pin P.