Sheet Aligning Device

1. Field of the Invention

This invention relates to a sheet aligning device in a copying apparatus, a printing machine, a recording machine or other various machines provided with a mechanism for supporting and containing sheets (hereinafter simply referred to as the copying apparatus or the like).

2. Description of the Prior Art

Some sheet aligning devices of this type in the copying apparatus or the like have been such that, for example, a rotatable paddle made of a plurality of elastic members of rubber or like material is directed in the direction of intersection of two surfaces substantially orthogonal to each other and is brought into contact with a sheet, whereby the sheet is aligned along guide members forming the two orthogonal surfaces, but when the sheet is curled or otherwise deformed, particularly, when the amount of sheets supported increases, there has been a disadvantage that sheet alignment is liable to be disturbed particularly in a portion spaced apart from the paddle.

In view of such disadvantage, it is an object of the present invention to provide an improved novel sheet aligning device.

It is another object of the present invention to provide a sheet aligning device which enables even curled or otherwise deformed sheets to be well aligned.

That is, the major construction of the present invention which can achieve the above objects consists in a sheet aligning device for aligning conveyed sheets by bringing rotatable paddles comprising a plurality of flexible members into contact with a sheet to be aligned against two surfaces substantially orthogonal to each other, characterized by a rotatable main paddle member for imparting to the sheet a draw-in force in the direction of intersection of the two surfaces substantially orthogonal to each other, and a rotatable auxiliary paddle member for causing the sheet to be conveyed to one of the two surfaces with a draw-in force weaker than the draw-in force of the main paddle member.

According to the construction of the present invention as described above, sheet alignment can be accomplished sufficiently well even when sheets are curled or otherwise deformed or even when the amount of sheets supported increases.

The invention will become more fully apparent from the following detailed description thereof taken in conjunction with the accmpanying drawings.

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a plan view of the FIG. 1 embodiment.

FIG. 3 is a plan view of showing another embodiment of the present invention.

Specific embodiments of the present invention will hereinafter be described in detail by reference to the drawings. FIG. 1 is a perspective view showing an embodiment of the present invention. In FIG. 1, reference numerals 1 and 2 designate a pair of paper discharge rollers which serve to feed paper 5 into the aligning device. Reference numerals 3 and 4 denote guide members whose planes are orthogonal to each other and which serve to bear against two side edges of the paper 5 and position the paper 5. A main paddle 6.sub.1 and an auxiliary paddle 6.sub.2 have their tip ends formed of an elastic or flexible material such as rubber and are rotated in the direction of the associated arrows by motors 7.sub.1 and 7.sub.2, respectively. The paddle 6.sub.1 faces the guides 3 and 4, and the paddle 6.sub.2 draws the paper toward the guide 4.

In the above-described construction, the paper 5 can be reliably positioned and aligned by the guides 3 and 4. Particularly, even if the paper is curled, the curl may be held down by the pressure force of the paddle 6.sub.2 and one side edge of the paper 5 may be reliably positioned by the guide 4. Of course, one lateral side edge of the paper 5 may be positioned and aligned along the guide 3 by the action of the paddle 6.sub.1.

Preferably, the material forming the tip end of the paddle 6 may be, for example, electrically conductive rubber to prevent their friction charging with the paper. According to experiment, it has been found that the following angles are most preferable as the angle between the draw-in direction of the paddles and the direction of entry of the paper. That is, the paddle 6.sub.1 should be inclined by 45.degree. with respect to the direction of movement of the paper and the paddle 6.sub.2 should be inclined by 0.degree. with respect to said direction (FIG. 2), or the paddle 6.sub.1, should be inclined by 30.degree. and the paddle 6.sub.2 should be inclined by 30.degree., with respect to the direction of movement of the paper (FIG. 3).

This is because, if both the paddle 6.sub.1 and the paddle 6.sub.2 are inclined by 45.degree., the lateral paper draw-in force will become stronger and if the paddle 6.sub.1 is inclined by 30.degree. and the paddle 6.sub.2 is inclined by 0.degree., the lateral paper draw-in force will be weaker.

The best angle of the paddles with respect to the direction of movement of the paper is variable by the difference in draw-in force between the paddles themselves.

Preferably, the paper draw-in force of the paddle 6.sub.2 may be somewhat weaker than the paper draw-in force of the paddle 6.sub.1, and this can be accomplished as by making the diameter of the paddle 6.sub.2 somewhat smaller than the diameter of the paddle 6.sub.1 or mounting the paddle 6.sub.2 at a position somewhat higher than the paddle 6.sub.1. In the embodiment illustrated, a good result has been obtained by adopting 100 mm as the diameter D of the paddles 6.sub.1 and 6.sub.2 and mounting the paddles 6.sub.1 and 6.sub.2 at a height of B=30 mm and a height of C=35 mm, respectively, in FIG. 1.

The above-described result has been obtained under the following conditions:

paper conveyance speed: about 500 mm/sec.

peripheral speed of paddle tip ends: about 1300 mm/sec.

shape of the rubber of paddle tip ends: width 10 mm thickness 2 mm

and the best mounting height is variable by a difference in these conditions.

Also, in the above-described embodiment, the paper supporting table may be designed to be elevated or lowered in order to ensure the best support height of the paper to be kept constant. The number of paddles may also be three or more, but as a result of the experiment, two paddles have been sufficient.