US3834690A

US3834690A - Device for separating copy carriers from a roll, drum or the like by means of a suction roll

Info

Publication number: US3834690A
Application number: US00271510A
Authority: US
Inventors: W Knechtel
Original assignee: Canon Inc
Current assignee: Canon Inc
Priority date: 1971-07-20
Filing date: 1972-07-13
Publication date: 1974-09-10
Anticipated expiration: 1991-09-10
Also published as: DE2136139B2; DE2136139A1

Abstract

A device for separating copy carriers such as copy paper sheets from a roll, drum or the like by means of a suction roll includes a wire, rod or like member extending obliquely in front of the suction roll. The wire, rod or like member is arranged so that when a copy carrier is fed forwardly its leading edge reaches the wire for point-contact therewith and as the copy carrier is further moved the point of contact is displaced along the leading edge of the copy carrier and along the wire, whereby the copy carrier is curved toward the suction roll by the wire.

Description

United States Patent 1191 1111 3,834,690 Knechtel Sept. 10, 1974 [5 DEVICE FOR SEPARATING COPY 3,572,694 3/1971 Wilde et al. 271/64 CARRIERS FROM A ROLL DRUM OR THE FOREIGN PATENTS OR APPLICATIONS LIKE BY MEANS OF A SUCTION ROLL 1,474,167 2/1969 Germany 271/65 [75] Inventor: Wilhelm Knechtel, Biebertal,

Germany Primary Examiner-Richard A. Schacher Assistant Examiner-James W. Miller [73] Asslgnee' E123, Kabushlkl Kalsha Tokyo Attorney, Agent, or Firm-Fitzpatrick, Cella, Harper & Scinto [22] Filed: July 13, 1972 [21] Appl. No.: 271,510 [57] I ABSTRACT A device for separating copy carriers such as copy [30] Foreign Application Priority Data paper sheets from a roll, drum or the like by means of a suction roll includes a wire, rod or like member ex- July 1971 Germany 2136139 tending obliquely in front of the suction roll. The wire, U S 2 rod or member is arranged so that when a 00p) [51] B65h 29/20 29/52 carrier is fed forwardly its leading edge reaches the [58] Fieid 271/60 2 64 M A wire for point-contact therewith and as the copy car- R 65 1 rier is further moved the point of contact is displaced along the leading edge of the copy carrier and along [56] References Cited the wire, whereby the copy carrier is curved toward UNITED STATES PATENTS the suction roll by the wire. 2,731,263 1/1956 B6111 et a1. 271/64 MA 3 Claims 2 Drawing Figures DEVICE FOR SEPARATING COPY CARRIERS FROM A ROLL, DRUM OR THE LIKE BY MEANS OF A SUCTION ROLL BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a device for separating copy carriers from a roll, drum or like member by means of a suction roll.

2. Description of the Prior Art In a copying apparatus, a copy paper sheet drawn as from a cassette is brought into contact with a negative latent image existing on a selenium drum and after image transfer, the copy paper sheet is separated from the drum. A suction roll is used to separate the copy paper sheet from the drum. The suction roll has its interior pressure decreased so as to suck air thereinto through a number of openings formed therein. The sucked air sucks the copy sheet so that the back side thereof is brought into contact with the outer surface of the suction roll. When such suction roll is used to separate copy paper sheets, its reliability depends on the types of copy paper sheets in use and is not always high. That is, the thicker are the copy paper sheets, the more difficult is the separation thereof from the drum.

SUMMARY OF THE INVENTION carriers themselves and the copies carried thereon.

According to the present invention, such an object may be achieved by disposing a wire, rod or like member extending obliquely in front of the suction roll so that when a copy carrier is fed forwardly the leading edge thereof reaches the wire to make a point-contact with the wire, and as the copy carrier is further moved the point of contact is displaced along the leading edge of the copy carrier and along the wire, whereby the copy carrier is curved toward the suction roll by the wire.

When a copy carrier such as a copy paper sheet is curved, only the leading edge thereof contacts the wire and thus, in the device of the present invention, the image-bearing surface of the copy carrier is never scratched or otherwise injured. Futhermore, the point of contact between the leading edge of the copy paper sheet and the wire is displaced with the advancement of the copy paper sheet so that the load exerted on the leading edge of the copy paper sheet is dissipated.

As soon as the copy carrier reaches the suction area of the suction roll, the copy carrier is sucked by the suction roll so that desired separation and deflection may be effected.

Preferably, the wire, rod or the like may extend helically around a portion of the suction roll in spacedapart relationship therewith.

It is further preferable that the distance of the wire, rod or the like from the suction roll be gradually decreased in the circumferential direction of the roll.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in greater detail with reference to the accompanying drawings, in which:

FIG. I is a fragmentary schematic view of the copying apparatus showing an embodiment of the present invention; and

FIG. 2 is an enlarged perspective view showing a portion of the apparatus of FIG. I.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, a drum I is rotatable about its axis A-A and provided with a negative latent image in an unshown manner. The negative latent image is directed into a developer tank 2. From a cassette 3 a copy paper sheet 4. is drawn and passed along a guide path 5, and then brought into contact with the drum I at an area thereof designated by reference numeral 6. A corona means 7 transfers the negative latent image onto the copy paper sheet 4 as a positive image. After the image transfer, the copy paper sheet 4 must be separated from the drum. For this purpose, use is made of a suction roll 7 which is rotatable in the direction of arrow 14. The suction roll 7 has a number of openings 8 through which air is sucked into the suction roll as a pressure reduction is caused within the suction roll. The air acts to separate the copy paper sheet 4 from the drum I. Depending on the thickness of the copy sheet 4- in use, the copy sheet may not always have its back side brought into contact with the suction roll 7 and thus it may sometimes not be deflected in a proper direction. To avoid this, a wire 10 fixed to the apparatus is disposed in front of the suction roll 7. As seen in FIG. 2, the wire 10 extends substantially helically around a portion of the suction roll. The distance between the suction roll 7 and the wire I0 is selected such that a copy paper sheet may enter the space between the suction roll 7 and the wire 10 in any event. When the leading edge of the copy paper sheet comes to the wire 10, the leading edge makes a point-contact with the wire 10. As the copy sheet is further moved, the point of contact is displaced along the leading edge and along the wire in the direction of arrow 11. Thus, the wire guides the copy paper sheet toward the suction roll, and the copy paper sheet progressively approaches the suction area of the suction roll 7 until the back side thereof is finally brought into contact with the suction roll 7. The suction roll 7 deflects the copy paper sheet toward fixing means I2.

I claim:

I. In a photocopying device including a roll or drum member for contacting a copy carrier, the improvement comprising a suction roll for separating the copy carrier from the drum member, and a helical wire member disposed adjacent said suction roll to engage only a point on a forward edge of said copy carrier and to guide said copy carrier into contact with said suction roll, said point of engagement of said leading edge with said helical wire member being displacable along said leading edge and along said wire member in response to advancing movement of said copy carrier, and said wire member extending obliquely with respect to the direction of movement of the copy carier.

2. A device according to claim I wherein said helical wire member extends helically around a portion of said suction roll in spaced relationship therewith.

3. A device according to claim I wherein the distance between said suction roll and said wire member gradually decreases in the circumferential direction of said roll.

Claims

1. In a photocopying device including a roll or drum member for contacting a copy carrier, the improvement comprising a suction roll for separating the copy carrier from the drum member, and a helical wire member disposed adjacent said suction roll to engage only a point on a forward edge of said copy carrier and to guide said copy carrier into contact with said suction roll, said point of engagement of said leading edge with said helical wire member being displacable along said leading edge and along said wire member in response to advancing movement of said copy carrier, and said wire member extending obliquely with respect to the direction of movement of the copy carier.

2. A device according to claim 1 wherein said helical wire member extends helically around a portion of said suction roll in spaced relationship therewith.

3. A device according to claim 1 wherein the distance between said suction roll and said wire member gradually decreases in the circumferential direction of said roll.