Sheet sending apparatus

Abstract: An apparatus for sending a sheet of paper to the sheet feeding mechanism of a copying machine or printer. The sheet sending apparatus comprises a manual sheet sending chute includng an upper chute (5) and a lower chute (6) articulated by gears (12,16) and an automatic sheet feeding cassette (3). When the chute is used, the upper and lower chutes (5,6) make a flat angle to smoothly pass a sheet to the feed roller (28), and the lower chute (6) press down the stacked sheets of the sheet cassette (3). When the apparatus is not used, the chutes rotate and the lower chute (6) leaves the feed roller. A sheet guide (38) is attached to the lower end of the lower chute (6) to prevent the sheet sliding on the chute from falling in the sheet cassette (3), and the parts (39a,39h) of the sheet guide corresponding to the separator (27a,27b) of the sheet cassette (3) is removed to allow natural flipping action of the sheet when the sheet is drawn out of the sheet cassette (3).

Description: The present invention relates to an apparatus for sending a sheet (of paper) to a sheet handling machine (such as a sheet feeding mechanism inside of a copying machine or a printer). BACKGROUND A typical copying machine has some sheet cassettes for different sheet sizes. Since automatic sheet feeding from the sheet cassettes is difficult for small and stiff sheets such as post cards or name cards, some copying machines are provided with a manual sheet-sending chute. In this case, a sheet feeding roller is prepared for each sheet cassette or the chute. Since a sheet is handled in only one of those at one time, the sheet feeding rollers are redundant. Japanese Published Examined Utility Model Application No. S63-4034 discloses a sheet sending mechanism including an automatic sheet-feeding cassette, a manual sheet-sending chute and a single sheet feeding roller, where the sheet-sending chute is tiltable. When the sheet-sending chute is used, the end of the chute is brought near to the sheet feeding roller, and when it is not used, the end retires remote from the sheet feeding roller. The prior art mechanism, however, needs a large stroke in moving the chute and much space to swing it. The large stroke needed to bring the chute to its operating position may sometimes cause difficulties in fixing it to the exact operable position. On the other hand, DE-A-31 35 751 discloses a sheet sending apparatus comprising a sheet cassette, a sheet separator provided at an edge of the sheet cassette and a sheet guide in accordance with the precharacterizing part of claim 1. SUMMARY OF THE INVENTION The object of the present invention is to provide an apparatus for sending a sheet to a sheet handling machine which prevents a guided sheet from falling in a cassette while allowing a flipping action of the uppermost sheet fleeing the sheet separator. Said object is achieved, according to the present invention, by an apparatus as claimed in claim 1, the characterizing feature being that the sheet guide is placed above the edge of the sheet cassette with the part corresponding to the sheet separator removed. Advantageous additional features of said apparatus are claimed in the sub-claims. The sheet sending apparatus of the present invention will be shown in the following description of the preferred embodiment and the attached drawings. BRIEF DESCRIPTION OF THE ATTACHED DRAWINGS Fig. 1 is a perspective view of a copying machine equipped with the manual sheet-sending chute of claim 2 and a sheet cassette. Fig. 2 is a side view of the sheet sending apparatus equipped with a resilient sheet guide at the lower end of the lower chute. Fig. 3 is a perspective view of the sheet guide. Fig. 4 is an explanatory view of the movement of the uppermost sheet when it is drawn out of the sheet cassette. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Fig. 1 is a perspective view of a copying machine equipped with a manual sheet-sending apparatus according to the present invention. The manual sheet-sending apparatus (only whose upper chute 5 is shown in Fig. 1) is attached at the entrance 2 of the housing 7 of the copying machine 1. A sheet cassette 3 is also inserted in the entrance 2. The housing 7 is horizontally divided to allow maintenance of the inside. The manual sheet sending mode is indicated by the lamp 8 on the top of the housing 7. The embodiment of the present invention is shown in more details in Fig. 2, in which a sheet guide 38 is attached to the lower edge of the lower chute 6. The sheet guide 38 is made of a thin, resilient sheet of film, such as a polyester film, and is attached to the upturn edge 17 with a two-sided adhesive tape, etc. The sheet guide 38 extends well beyond the front (left in Fig. 2) edge of the sheet cassette 3 in order to prevent the sheet sliding on the chutes 5 and 6 from falling in the cassette 3 and to convey the sheet right to the sheet feeding mechanism inside of the copying machine 1. The free end of the sheet guide 38 is made further resilient by forming a plurality of tongues 39a-39h as shown in Fig. 3. If the copying machine 1 is adapted to handle a small sized sheet (such as a post card or name card) , it is preferable to make the central tongues 39d and 39e thicker to assuredly support such a small sheet. The side end pieces 39a and 39h of the tongues are made shorter in order to assure the flipping action of the sheet being sent out from the sheet cassette 3. The process is detailed with reference to Fig. 4. When the uppermost sheet of the sheet cassette 3 is to be fed, first the side corners of the sheet is temporarily held by the separators 27a and 27b of the cassette 3 while the sheet itself is being pushed forward. The central part of the front edge of the sheet bends as shown by the solid line 40, which ensures separation of the uppermost sheet from the second sheet on the sheet stack in the cassette 3. When the sheet is further pushed forward, the corners finally flee from the separators 27a and 27b and flip upward as shown by the dashed line 41. The flipping action of the corners is important for the front edge of the sheet to successfully escape from the sheet cassette 3. The end tongues 39a and 39h are made short so that it allows the flipping action of the corners of the sheet being drawn out of the cassette 3. If the sheet guide 38 is made of a resilient rectangular sheet without the tongues, the corners corresponding to the separators 27a and 27b are to be cut off. Anyway, the important thing is that the part of the sheet guide corresponding to the separator of the sheet cassette is removed to allow the flipping action of the sheet fleeing the separator.

Claims: An apparatus for sending a sheet to a sheet handling machine comprising: a sheet cassette (3) for containing a plurality of stacked sheets (22); a sheet separator (27a, 27b) provided at an edge of the sheet cassette (3) for separating a sheet being drawn out of the sheet cassette from the other sheets remaining in the sheet cassette; and a sheet guide (38), characterized in that the sheet guide (38) is placed above said edge of the sheet cassette (3) with the part (39a, 39h) corresponding to the sheet separator (27a, 27b) removed. The sheet sending apparatus according to claim 1, where a chute is provided for manually sending a sheet to the sheet handling machine including an upper chute plate (5) and a lower chute plate (6) articulated to each other; the sheet cassette (3) is provided below the chute for automatically sending a sheet to the sheet handling machine, the sheet separator (27a, 27b) is provided at the edge of the sheet cassette nearest to the sheet handling machine; and the sheet guide (38) is attached to the lower end of the lower chute plate (6) and extending toward the sheet handling machine above said edge of the sheet cassette (3) for guiding a sheet being sent from the chute to the sheet handling machine. The sheet sending apparatus according to claim 2, where each chute plate (5, 6) has an axis of rotation (11, 15) different from that of the other, whereby the manual sheet sending chute is fixable at two positions, one being an operable position where the upper chute plate (5) and the lower chute plate (6) make a substantially flat angle and an end of the lower chute plate (6) is proximate to the sheet handling machine, and the other being a retired position where the upper chute plate (5) and the lower chute plate (6) make a different angle and the end of the lower chute plate (6) is distant from the sheet handling machine. The sheet sending apparatus according to claim 1 or 3, where a plurality of tongues (39a - 39h) are provided at the free end of the sheet guide (38), and the tongues at both sides are short. The sheet sending apparatus according to claim 4, where central tongues (39d, 39e) are stiffer than the other tongues. The sheet sending apparatus according to claim 5, where the sheet guide (38) is made of a plastic sheet.

Inventors: NAKAMURA TOSHIYUKI, NAKAMURA, TOSHIYUKI
Applicants: MITA INDUSTRIAL CO LTD, MITA INDUSTRIAL CO. LTD.
Application year: 1990
Main classification: G03G15
IPC codes: G03G15, B65H5