JP2571636Y2 - Sheet transfer device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a sheet transfer device including a transfer roller, a roller for sandwiching and feeding a sheet between the transfer roller, and a pressing member such as a leaf spring. For example, the present invention relates to an apparatus for discharging a document sheet to a discharge tray of an image forming apparatus.

2. Description of the Related Art In a conventional sheet transfer apparatus, as shown in the drawings of Japanese Utility Model Application Laid-Open No. 62-92256, for example, a so-called paddle member such as a radial fin member 6 is provided as a separate member coaxially with a shaft of a transfer roller. Was arranged. The diameter of the envelope connecting the tip portions of such paddle members is generally slightly larger than the diameter of the coaxial transfer roller.

The paddle member contacts the sheet surface of the sheet to be transported and is strongly advanced. In particular, by hitting the trailing edge of the sheet from behind, the forward movement is momentum. Has the effect that the trailing end of the sheet does not remain when the sheet is discharged.

[Problem to be Solved by the Invention] However, in the conventional sheet transfer device having such a paddle member, not only the striking sound of each tongue member of the paddle member hitting the sheet surface becomes annoying noise, Depending on the quality of the sheet, there is a problem that the sheet is damaged by the impact.

[Purpose of the Invention] The present invention has been made in view of such a problem, and does not hit the sheet surface which causes noise, does not damage the sheet, and furthermore, the sheet to be conveyed. An object of the present invention is to provide a sheet transfer device that includes a paddle-compatible member that can strongly push a trailing edge, and that does not cause a trailing end of a sheet to be applied to a position where a sheet is discharged to a discharge tray, for example. I have.

[Means for Solving the Problems] An object of the present invention is to provide a sheet transfer apparatus including a transfer roller and a pressing member for holding the sheet between the transfer rollers and feeding the sheet, wherein the transfer roller has a circumferential surface. A roller having at least one tongue member protruding from the circumferential surface of the roller along the circumferential direction and being pressed by the pressing member from the base end side as the roller rotates. This is achieved by a sheet transfer device having an arcuate concave portion provided at least on the inner base end of the member and integrally formed of an elastic material.

[Operation] When the transfer roller starts to rotate, the tongue piece member is also ejected from the roller peripheral surface by the application of centrifugal force. The pressing member that is in contact with the peripheral surface of the transfer roller is configured to contact from the base side of the tongue member as the roller rotates, so that the pressing member contacts the tongue member. When the contact starts, the repelling amount of the tongue member gradually decreases, and when the tip of the tongue member contacts the pressing member, the tongue member is completely flush with the transfer roller.

Even in the case where the sheet intervenes between the transfer roller and the pressing member, the tongue member gradually falls down by the pressing member in the direction approaching the sheet. No noise and therefore no noise.

Then, when the tip of the tongue member leaves the contact point with the pressing member, centrifugal force is also applied to repel the external force, and the sheet contacts the sheet surface and is sent forward. Usually, a plurality of such tongue members are provided in the circumferential direction, so that any one of the tongue members exactly hits the trailing edge of the sheet and acts to repel it forward. Therefore, even when such a sheet transfer device is provided in, for example, a discharge section of an image forming apparatus, the trailing end of the sheet remains without being completely discharged, that is, the so-called trailing end of the sheet does not occur.

[Embodiments] Various embodiments of the present invention will be described below with reference to the drawings.

1 to 3 (c) show a first embodiment of the invention.

As an example of an apparatus in which the sheet transfer apparatus 30 is applied to FIG.
A reversing discharge unit of a document feeder 10 placed on a platen P of the image forming apparatus C and feeding a document sheet to the platen P
Indicates 20.

The document feeder 10 separates the document sheets one by one in a paper supply unit (not shown), and uses a conveyance belt 12 stretched between a conveyance roller 11 and another conveyance roller (not shown) forming a pair with the conveyance roller 11. After being sent onto the platen P and localized at a predetermined position on the platen P, it is subjected to exposure processing by the image forming apparatus C. Then, the original sheet after the exposure processing is sent to the conveyor belt 12 again,
Sent to 20.

The original sheet fed to the reversing discharge unit 20 is a reversing roller
The document is fed along the guide plate 22 by the guide 21, but when the reversing mode is selected by a selecting means (not shown) of the apparatus 10, the reversing switching claw 24 is rotated clockwise, and the original sheet is moved by the reversing guide plate. It is fed again to the lower part of the conveyor belt 12 along the line 23. Then, the original sheet is repositioned on the platen P in a state where the original sheet is turned upside down by the reverse rotation of the transport roller 11, and undergoes exposure processing on the back side.

After completing all processing, the original sheet is
The sheet is fed along 22 and will be discharged to the outside by the sheet transfer device 30 after passing between the upper surface of the reversing switching claw 24 and the discharge guide plate which is rotating counterclockwise.

As shown in FIG. 2, the sheet transfer device 30 includes a transfer roller 31 serving as a discharge roller for discharging a document sheet, and a pressing roller 40 serving as a pressing member for pressing the document sheet from above.

The transfer roller is a discharge roller of the reversing discharge unit 20 in this application example, and hence is referred to as a discharge roller 31 hereinafter.

The discharge roller 31 is composed of a roller part 33 and three paddle pieces 34 as three tongue pieces provided evenly on the cylindrical peripheral surface. The roller shaft 32 is connected to driving means (not shown).

The paddle piece 43 is formed integrally with the roller portion 33, and is made of, for example, an elastic material such as rubber.

Each paddle piece 34 is, as shown in FIG. 2 and FIG.
It protrudes gently outward from the base portion 34a toward the distal end portion 34b, and has elasticity to repel outward when the distal end portion 34b is pressed and released. When the paddle piece 34 is completely pressed down, the rear surface 34d thereof coincides with the outer surface of the roller portion 33, and forms the cylindrical peripheral surface of the discharge roller 31 as a whole. A relief portion 34c (arc-shaped concave portion) having a circular cross section is formed at a joint between the inner base portion and the roller portion 33 to avoid stress concentration and for convenience in molding.

The discharge roller 31 is a paddle piece as shown in FIG.
The pressing roller 40 is configured to rotate in a direction indicated by an arrow A in FIG.
Is configured to contact and advance from the base portion 34a toward the tip portion 34b.

Although the pressing member is the pressing roller 40, the pressing member may be a plate-like body that slides on the surface of the discharge roller 31 instead of the roller body.

 Next, the operation will be described.

As shown in FIG. 3A, the pressing roller 40 is connected to the discharging roller 31.
When in the base 34a near the paddle piece 34 (I), the original sheet S ₁ is came sent. However, this is for convenience of explanation, and the original sheet is not always fed in this state, and the pressing roller 40 and the discharging roller 31 may be at any position regardless of the phase shift. At the point of contact between 40 and the discharge roller 31, the outer periphery of the paddle piece 34 is
It goes without saying that the document sheet can be cut into the outer periphery of the document.

By the rotation of the discharge roller 31, the paddle piece 34 (I) is pressed by the pressing roller 40 as shown in FIG.
The shape gradually approaches the outer peripheral shape of the roller portion 33, and finally becomes completely cylindrical as shown in FIG. 3 (c). In this way, the paddle piece 34 forms a cylindrical surface only at the position in contact with the pressing roller 40, and does not hit the paper surface of the original sheet, so that it does not emit noise due to hitting, and does not hit due to paper quality. There is no damage from.

Then by the rotation of the several times of the discharge roller 31, ultimately the document sheet S ₁ of the preceding, as FIG. 3 (d) are are discharged vigorously pressed then edge by II, for example paddles 34 Also, there is no possibility that the trailing edge of the original sheet is caught and left near the discharge port. Then, after the preceding document S ₁ is retracted the next original sheet S _2.

Although the trailing edge of the original sheet is not always pushed out by the paddle pieces 34 as shown in FIG. 3D, the ratio of the paddle pieces 34 to the entire circumference of the discharge roller 31 is very large. Even if the abutting positions on the paddle pieces 34 are different, the trailing edge of the document sheet is pushed out by the paddle pieces 34 at a high rate.

Even if the paddle piece 34 is not pushed as shown in FIG. 3 (d), the peripheral speed of the tip portion 34b of the paddle piece 34 is much higher than that of the roller portion 33, and a material having a high surface friction coefficient such as rubber can be used. As a result, the discharged original sheet is always violently repelled and no trailing end remains.

FIG. 4 shows a sheet transfer apparatus 50 according to a second embodiment. The tongue piece member 52 of the transfer roller 51 according to the second embodiment has a circumferentially symmetrical shape.
It is provided in several places.

The operation and effects are described in the first section above.
The description is omitted because it is the same as the embodiment. However, such a configuration is suitable for a relatively small transfer roller.

[Brief description of the drawings]

FIGS. 1 to 3 (d) show a first embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a reversing / discharging section of a document feeder to which a sheet transfer device is applied, and FIG. FIGS. 3 (a) to 3 (d) are perspective views of the sheet transfer device, and FIGS. 3 (a) to 3 (d) are operation explanatory diagrams, and FIG. 4 is a configuration diagram of a second embodiment of the device. 10 Document feeder 20 Reversal discharge unit 30 Sheet transport device 31 Discharge roller (transfer roller) 33 Roller unit 34 Paddle piece (tongue piece member) 34a Base (base end) ), 34b: Tip portion 34c: Relief portion, 34d: Back surface 40: Press roller (press means)

Claims (1)

(57) [Scope of request for utility model registration] 1. A sheet transfer apparatus comprising: a transfer roller; and a pressing member for holding the sheet between the transfer roller and feeding the sheet, wherein the transfer roller has a roller portion having a circumferential surface; At least one tongue member that protrudes from the circumferential surface of the roller portion in the circumferential direction and is pressed by the pressing member from the base end side with the rotation of the roller portion, and provided at least on the inner base end of the tongue member. A sheet transfer device having an arc-shaped concave portion formed integrally with an elastic material.