1. A sheet feeding apparatus comprising:
rotatable feeding means for feeding a sheet by rotation thereof;
supporting means, having a supporting portion movable toward and away from the rotatable feeding means, for supporting a plurality of stacked sheets from a side opposite from the rotatable feeding means, and for elastically causing one sheet closest to the rotatable feeding means to contact the rotatable feeding means;
separating means, having an abutting portion movable toward and away from the rotatable feeding means, for elastically holding the sheets between the abutting portion and the rotatable feeding means, and for separating the sheets so as to allow only the one sheet closest to the rotatable feeding means to be fed out with the rotation of the rotatable feeding means, the separating means being disposed downstream of the supporting means in a sheet feeding direction;
sheet separating means for displacing remaining sheets in a direction away from the rotatable feeding means when the one sheet has been advanced to a target position reaching sheet transporting means disposed downstream in the sheet feeding direction;
abutting portion separating means for moving the abutting portion in a direction away from the rotatable feeding means so as to release the holding of the sheets between the abutting portion and the rotatable feeding means when the one sheet has reached the target position; and
limiting means for preventing the remaining sheets, excluding the one sheet, from moving downstream in the sheet feeding direction when the one sheet has reached the target position;
wherein the sheet separating means and the limiting means are integrally disposed.
2. The sheet feeding apparatus of claim 1, wherein the sheet separating means is provided adjacent to the rotatable feeding means, and displaces the remaining sheets near the rotatable feeding means by pressing the sheets from a side adjacent to the rotatable feeding means.
3. The sheet feeding apparatus of claim 1, wherein the limiting means aligns leading edges of leftover sheets which are sheets fed to the separating means from the remaining sheets by the rotatable feeding means and separated from the one sheet by the separating means.
4. The sheet feeding apparatus of claim 3, wherein
the sheet separating means pushes back leftover sheets upstream of the separating means in the sheet feeding direction; and
the limiting means aligns and supports the leading edges of the leftover sheets pushed back by the sheet separating means.
5. The sheet feeding apparatus of claim 1, further comprising:
a common drive shaft member rotatably supported, for driving in common the sheet separating means, the abutting portion separating means, and the limiting means which are connected together;
a rotational driving source; and
transmitting means for transmitting a drive force from the rotational driving source to the common drive shaft member, the transmitting means having a partially toothed gear with teeth formed only on a portion of a circumference thereof.
6. The sheet feeding apparatus of claim 1, further comprising:
a feed shaft member rotatably supported, the rotatable feeding means being connected thereto;
a common drive shaft member rotatably supported, for driving in common the sheet separating means, the abutting portion separating means, and the limiting means which are connected thereto together;
a rotational driving source; and
transmitting means for transmitting a drive force from the rotational driving source to the feed shaft member and the common drive shaft member, the transmitting means having a sun gear which rotates in an interlocking fashion with an output shaft of the rotational driving source, a feed input gear which is mounted in an area surrounding the sun gear and rotates in an interlocking fashion with the feed shaft member, a common input gear which is mounted in the area surrounding the sun gear and in a position circumferentially spaced apart from the feed input gear and rotates in an interlocking fashion with the common drive shaft member, and a planet gear which is in meshing engagement with the sun gear, and
the planet gear being mounted so as to be movable around the sun gear between a feed input position, where rotational force is transmitted to the feed input gear, and a common input position, where rotational force is transmitted to the common input gear.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A hydraulic composition comprising cement (A), a copolymer (B), a high-performance water reducing agent (C) which is a polycarboxylic acid based high-performance water reducing agent, and a powdery admixture for cement (D) being at least one species selected from the group consisting of blast-furnace slag, fly ash and limestone, wherein the copolymer (B) comprises a repeating unit (I) represented by the following formula (1);
wherein R1 represents a hydrogen atom or a methyl group. n is an integer of 2 to 4, and a repeating unit (II) represented by the following general formula (2);
wherein R2, R3 and R4 are same or different and each represents a hydrogen atom, a methyl group or a (CH2)pCOOM2 group, and may form a structure of an anhydride when the total number of COOM1 groups and COOM2 groups are 2. M1 and M2 are same or different and each represents a hydrogen atom, a monovalent metal, a divalent metal, an ammonium group or an organic ammonium group, and p is an integer of 0 to 2 and wherein said copolymer (B) has a weight average molecular weight of 600,000 to 10,000,000.
2. A method of producing the hydraulic composition according to claim 1, wherein said copolymer (B) and said high-performance water reducing agent (C) are previously mixed and the resulting mixture is added.
3. The hydraulic composition according to claim 1, wherein said hydraulic composition comprises the powdery admixture for cement (D) in an amount of not less than 5% by mass based on 100% by mass of cement (A).
4. The hydraulic composition according to claim 3, wherein said hydraulic composition comprises the copolymer (B) in an amount of 0.000 1 to 0.5% by mass, the high-performance water reducing agent (C) in an amount of 0.01 to 5% by mass and the powdery admixture for cement (D) in an amount of 5to 200% by mass based on 100% by mass of cement (A).
5. The method of the producing the hydraulic composition according to claim 2, wherein said hydraulic composition comprises the powdery admixture for cement (D) in an amount of not less than 5% by mass based on 100% by mass of cement (A).
6. The method of the producing the hydraulic composition according to claim 5, wherein said hydraulic composition comprises the copolymer (B) in an amount of 0.0001 to 0.5% by mass, the high-performance water reducing agent (C) in an amount of 0.01 to 5% by mass and the powdery admixture for cement (D) in an amount of 5 to 200% by mass based on 100% by mass of cement (A).