Feeding mechanism

Abstract

A feeding mechanism. The feeding mechanism comprises a roller and a blocking plate. The blocking plate rotates between a first position and a second position, abutting a sheet when in the first position, and the sheet sliding thereon by gravity when in the second position. Particularly, the blocking plate and the sheet form an included angle larger in the first position than in the second position.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates in general to a feeding mechanism, and more particularly, to a feeding mechanism having a rotatable blocking plate capable of positioning media sheets precisely.

2. Description of the Related Art

Generally, conventional business machines, such as printers, have a media positioning device keeping sheet media in a predetermined position such that the sheets can be fed smoothly. Referring to FIG. 1a, a conventional feeding mechanism has an arm 1, a movable restraint 2 and a tray 20, wherein a roller 10 is disposed at the end of the arm 1. When the arm raises and the roller 10 leaves the sheets S, the restraint 2 lifts and abuts the sheets S in a predetermined position. When feeding the sheets S, as shown in FIG. 1b, the restraint 2 lowers such that the roller 10 contacts and drives the sheets S.

As mentioned, the restraint 2 abuts the sheets S in a predetermined position, however, multiple sheets may be fed, or improperly fed.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide a feeding mechanism capable of positioning media sheets precisely, preventing multiple sheets intake and improper feed. The feeding mechanism comprises a roller and a blocking plate. The blocking plate rotates between a first position and a second position, abutting a sheet in the first position, and the sheet sliding thereon by gravity in the second position. Particularly, the blocking plate and the sheet form an included angle larger in the first position than in the second position.

DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings, given by way of illustration only and thus not intended to be limitative of the present invention.

FIG. 1a and 1b are perspective diagrams of a conventional feeding mechanism.

FIG. 2a and 2b are perspective diagrams of a feeding mechanism in accordance with the present invention.

FIG. 2c, 2d and 2e are perspective diagrams of a blocking plate rotating between the first and second positions in accordance with the present invention.

FIG. 3a is a perspective diagram of a shaft rotating a cam in accordance with the present invention.

FIG. 3b is a perspective diagram of a cam in accordance with the present invention.

FIG. 4a is a perspective diagram of the cam rotating counterclockwise to a maximum position.

FIG. 4b is a perspective diagram of the cam rotating clockwise to a maximum position.

FIG. 4c is a perspective diagram of the blocking plate returning to the first position.

DETAILED DESCRIPTION OF THE INVENTION

An object of the present invention is to provide a feeding mechanism preventing multiple sheets intake and improper feed. Referring to FIG. 2a, the feeding mechanism is applied to a business machine, such as a printer or a scanner, has a roller R, a shaft L, a movable blocking plate 30, a cam 4, a tray 5 and a cover 6. The blocking plate 30 is connected to a torsion spring 31 and is rotatable between a first position 3 and a second position 3′. The roller R is fixed to the shaft, and the cam 4 has a depression 410 and is rotatable on the shaft L. When in the first position 3, as shown in FIG. 2a, the blocking plate 30 abuts the cam 4 in the depression 410. Moreover, to feed the sheets S, the cam 4 rotates around the shaft L clockwise such that the blocking plate 30 is pushed down to the second position 3′. Subsequently, the sheets S on the tray 5 are driven by the roller R. As shown in FIG. 2b, the shaft L is fixed to the cover 6 and passes through the roller R and the cam 4. When the cover 6 opens, the cam 4 and the roller R are separated from the blocking plate 30, and the blocking plate 30 is returned to the first position 3 by the torsion spring 31.

Referring to FIG. 2c, when in the first position 3, the blocking plate 30 is approximately perpendicular to the sheets S, wherein the sheets S slide down and abut the blocking plate 30 by gravity. In FIG. 2d, when the blocking plate 30 shifts to the second position 3′, the sheets S and the blocking plate 30 form an obtuse angle such that the sheets S spontaneously slide on the smooth surface of the blocking plate 30 by gravity.

Particularly, when the blocking plate 30 rotates from the first position 3 to the second position 3′, the upper sheets S slip a larger distance than the lower sheets S due to less frictional force and higher velocity transferred from higher potential energy. Thus, as shown in FIG. 2d, the upper sheets S spontaneously progress forward by gravity to be fed properly. The staggered sheets S are loose and capable of being fed without accidental feeding of multiple sheets.

FIG. 2e shows the blocking plate 30 rotating between the first position 3 and the second position 3′, wherein the torsion spring 31 exerts a force returning the blocking plate 30 to the first position 3. Referring to FIGS. 3a and 3b, the shaft L passes through the roller R, the cam 4 and the driving assembly D, wherein the driving assembly D rotates the cam 4. The driving assembly D has a frictional member F, a spring P and a fixed portion E fixed to the shaft L. When the shaft L rotates the roller R and the driving assembly D, the cam 4 is driven by the frictional force between the frictional member F and the cam 4.

The cam 4, as shown in FIG. 3b, has a contacting portion 41, a restraining portion 42 and a through hole 40 through which the shaft L passes. The contacting portion 41 has a depression 410 disposed thereon and rotates the blocking plate 30 between the first position 3 and second position 3′. Moreover, the restraining portion 42 has a protrusion 421 restricting the cam 4's rotation to within a limited range. Referring to FIGS. 4a and 4b, when the cam 4 rotates counterclockwise to a maximum position, the protrusion 421 of restraining portion 42 abuts the protruding restraint 61 of the cover 6, wherein the blocking plate 30 is located in the depression 410 and the first position 3. Thus, the sheets S are precisely positioned on the tray 5.

To feed the sheets S, as shown in FIG. 4b, the shaft L rotates the roller R, the driving assembly D and the cam 4 clockwise, wherein the cam 4 pushes the blocking plate 30 to the second position 3′and the protrusion 421 abuts the restraint 61. Particularly, if the shaft L further rotates the roller R and the driving assembly D beyond the maximum position, the cam 4 is held with the frictional member 421 sliding thereon, and the spring P provides elastic force such that the frictional member 421 contacts and slides with respect to the cam 4. Thus, the roller R feeds the sheets S properly.

After feeding the sheets S, the shaft L rotates the cam 4 and the driving assembly D counterclockwise to the maximum position as shown in FIG. 4c. Thus, the protrusion 421 abuts the restraint 61 such that the cam 4 is restricted preventing obstruction of the blocking plate 30. In summary, the present invention provides a feeding mechanism having a movable blocking plate 30 capable of positioning media sheets precisely, preventing multiple sheets intake and improper feed.

While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation to encompass all such modifications and similar arrangements.

Claims

1. A feeding mechanism, comprising:

a roller; and

a blocking plate, rotating between a first position and a second position, abutting a media sheet in the first position, and the sheet sliding on the blocking plate by gravity in the second position, wherein the blocking plate and the sheet form an included angle larger in the first position than in the second position.

2. The feeding mechanism as claimed in claim 1 further comprising a torsion spring connected to the blocking plate, around which the blocking plate rotates.

3. The feeding mechanism as claimed in claim 1, wherein the blocking plate is substantially perpendicular to the sheet in the first position.

4. The feeding mechanism as claimed in claim 1, wherein the torsion spring provides a force driving the blocking plate to the first position.

5. The feeding mechanism as claimed in claim 1 further comprising a shaft and a cam, wherein the cam rotates around the shaft and rotates the blocking plate between the first and second position.

6. The feeding mechanism as claimed in claim 5, wherein the cam comprises a depression with the blocking plate located therein when in the first position.

7. The feeding mechanism as claimed in claim 5 further comprising a driving assembly comprising a fixed portion and a frictional member, wherein the fixed portion connects to the shaft, and the frictional member contacts and rotates the cam.

8. The feeding mechanism as claimed in claim 7, wherein the driving assembly further comprises a spring connecting the fixed portion and the frictional member.

9. The feeding mechanism as claimed in claim 5 further comprising a restraint fixed thereto, wherein the cam has a protrusion abutting the restraint when the cam rotates to a maximum position.

10. The feeding mechanism as claimed in claim 9 further comprising a driving assembly having a fixed portion and a frictional member, wherein the fixed portion connects to the shaft, and the frictional member slides on the cam when the cam rotates beyond the maximum position.