Claims
- 1. A developing device comprising:
- a frame, and
- a developing mechanism that is supported by said frame to move over a predetermined range in a direction toward and away from a surface of a rotary drum,
- a plurality of urging means for urging said developing mechanism in said direction toward the surface of said rotary drum, said developing mechanism including
- a developing housing
- a developing agent application means
- a support shaft means for mounting said developing agent application means on said developing housing,
- a pair of distance setting rollers rotatably arranged on both sides of said developing agent application means,
- said pair of distance setting rollers being brought into contact with the surface of said rotary drum by an urging action of said urging means to position said developing mechanism at a predetermined developing position with respect to said rotary drum
- said urging means urging said developing mechanism in said direction toward said rotary drum by said support shaft means
- said support shaft means having ends which protrude outwardly beyond both sides of said developing mechanism,
- urging means of said plurality being disposed on both sides of said developing mechanism to urge both ends of said support shaft means,
- each of said urging means being provided with a pushing means which contacts an end of said support shaft means,
- at least one of said pushing means coming into contact with said support shaft means in order to impart a thrust force to said support shaft in an axial direction.
- 2. A developing device according to claim 1, wherein said pushing means which contacts said ends of said support shaft means is a first pushing means and wherein a second pushing means comes into contact with an opposite end of said support shaft means to receive said thrust force imparted by said first pushing means.
- 3. A developing device according to claim 1, wherein said frame further includes:
- side plates arranged at both ends of said developing mechanism at a predetermined distance relative to both sides of said developing mechanism,
- guide groove means being formed in inner surfaces of said side plates to extend in the direction in which said developing mechanism moves toward and away from said rotary drum,
- said guide groove means corresponding to said developing mechanism and having first ends which are closed on a side closer to said rotary drum, and second ends which are open on a side remote from said rotary drum, said groove means being open on inner sides facing each other,
- support protrusion means provided outwardly protruding from both sides of said developing housing of said developing mechanism, said ends of said support shaft means and said support protrusion means being engaged with said corresponding guide groove means so that said developing mechanism is supported by said frame to move within said guide groove means, and said urging means being arranged within corresponding guide groove means.
- 4. A developing device according to claim 3, wherein each of said urging means includes a position restriction means which restricts movement of the development mechanism a predetermined distance away from said rotary drum,
- said pushing means being detachably engagable with said position restriction means, and
- said position restriction means having a compression coiled spring provided between said pushing means and said position restriction means.
- 5. A developing device according to claim 4, wherein said pushing means comprises:
- a cylindrical main body,
- a pushing portion formed at a first end of said main body,
- a pair of engaging projections that project from a second end of said main body in an axial direction which are arranged at a predetermined distance relative to each other, and
- engaging pawls formed at the ends of said pair of engaging projections,
- said pair of engaging projections distortable in a direction in which said engaging pawls approach each other, and
- said position restriction means includes
- a cylindrical portion having a fitting hole in which said main body is fitted to move relative thereto and an engaging lever provided at an end of said cylindrical portion at right angles thereto,
- said cylindrical portion having a pair of engaging grooves which each extend in the axial direction at a predetermined width and have both ends closed,
- said engaging pawns being engaged with said pair of engaging grooves so that said pushing means is engaged with said position restriction means to move over a predetermined range in the axial direction under a fitting hole of said cylindrical portion,
- said engaging pawls having such a size in the radial direction that said engaging pawls engage with said pair of engaging grooves so as not to escape from said pair of engaging grooves,
- said compression coiled spring being arranged about a periphery of said main body in a manner such that one end thereof comes into contact with one end of said pushing portions and an other end thereof comes into contact with the other end of said cylindrical portion, and
- said pair of engaging grooves having a width in the radial direction such that said position restriction means is allowed to rotate by a predetermined angle with respect to said pushing means under a condition where said pushing means is in engagement with said position restriction means.
- 6. A developing device according to claim 5, wherein
- engaging holes are formed in said side plates of said frame member, and
- engaging levers which are rotatable to a predetermined angle are brought into engagement with said engaging holes to determine a distance of said position restriction means in said direction away from said rotary drum.
- 7. A developing device according to claim 5, wherein a tilted surface is formed on a first pushing portion provided for an urging means, said tilted surface comes into contact with one end of said support shaft means to impart a thrust force thereon in the axial direction of said support shaft.
- 8. A developing device according to claim 7, wherein a second pushing portion provided for an other urging means has a first stepped portion constituted by a surface that comes into contact with said support shaft means to urge said support shaft means toward the direction to approach said rotary drum and a second surface that receives said thrust force imparted by said first pushing portion.
- 9. A developing device according to claim 8, wherein said second surface that receives said thrust force is a tilted surface.
- 10. A developing device according to claim 3, wherein said guide groove means further includes
- first guide grooves that extend in the moving direction of said developing mechanism and
- second guide grooves formed in parallel with said first guide grooves, both ends of said support shaft means being engaged with said first guide grooves to move in said moving direction,
- said support protrusion means being engaged with said second guide grooves to move in said moving direction,
- each of said support protrusion means including a plate member having a substantially rectangular shape, and
- each of said second guide grooves being engaged by said plate member to freely move and each of said second guide groove having a substantially rectangular shape.
- 11. A multi-color developing device comprising:
- a stationary frame,
- a movable frame mounted on said stationary frame so as to be reciprocatingly moved by a moving means in a predetermined direction,
- a plurality of developing mechanisms disposed in said movable frame and supported so as to move over a predetermined range in a direction toward and away from a rotary drum, and
- a plurality of urging means disposed for each of said developing mechanisms to urge each of said developing mechanisms in the direction toward said rotary drum, in which each of said developing mechanisms includes a developing housing and a developing agent application means mounted within said developing housing via a support shaft means,
- a pair of distance setting rollers rotatably arranged on both sides of each of said developing agent application means,
- said movable frame being moved by said moving means in said predetermined direction and each of said developing mechanisms being selectively positioned at a predetermined developing position so that the developing operation is carried out for a different color,
- said pair of distance setting rollers being brought into contact with the surface of said rotary drum when a developing mechanism is located at said predetermined developing position,
- said developing mechanism located at said predetermined developing position being movable in said direction to separate away from said rotary drum against the urging action of said urging means disposed for said developing mechanism
- each of said developing mechanisms being selectively positioned at said predetermined developing position in turn, wherein each of said urging means urges each of said developing mechanisms in said direction toward said rotary drum by each of said support shaft means,
- said support shaft means having ends which protrude outwardly beyond both sides of said developing mechanism, urging means of said plurality of urging means being disposed on both sides of said developing mechanism to urge both ends of said support shaft means,
- each of said urging means being provided with a pushing means which contacts an end of said support shaft means,
- at least one of said pushing means coming into contact with said support shaft means in order to impart a thrust force to the support shaft in an axial direction thereof.
Priority Claims (3)
Number |
Date |
Country |
Kind |
3-67649 |
Mar 1991 |
JPX |
|
3-67651 |
Mar 1991 |
JPX |
|
3-69407 |
Mar 1991 |
JPX |
|
Parent Case Info
This is a divisional of co-pending application Ser. No. 07/845,319 which was filed on Mar. 3, 1992, now U.S. Pat. No. 5,311,260 which is incorporated entirely herein by reference.
US Referenced Citations (4)
Divisions (1)
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Number |
Date |
Country |
Parent |
845319 |
Mar 1992 |
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