SHEET FEEDING APPARATUS AND IMAGE FORMING APPARATUS

Abstract

A lifting plate provided in a sheet accommodating member is locked at a position, to which the lifting plate is downwardly turned against a pushing force of a spring, by a locking mechanism having a locking member configured to lock the lifting plate, and also having a lock releasing lever configured to release locking of the lifting plate by the locking member. When the sheet accommodating unit is mounted, the lock releasing lever is made to abut against a lock release member. Thus, the lock releasing lever is moved integrally with the locking member in a lock release direction. When the sheet accommodating unit is drawn out, the lock releasing lever is made to abut against the lock release member. Thus, the lock releasing lever is singly moved in a direction opposite to the lock release direction to maintain the locking of the lifting plate by the locking member.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the invention and, together with the description, serve to explain the principles of the invention.

FIG. 1 is a schematic diagram illustrating an example configuration of a laser printer which is an example of an image forming apparatus according to an exemplary embodiment of the present invention.

FIG. 2 is a diagram illustrating an example configuration of a cassette mounting unit provided in a printer body of the laser printer and also illustrating the configuration of a sheet cassette demountably mounted in the cassette mounting unit.

FIG. 3 is a diagram illustrating an example state in which a lifting plate provided in the sheet cassette is locked by a locking mechanism.

FIGS. 4A and 4B illustrate an example configuration of the locking mechanism.

FIGS. 5A and 5B illustrate an example operation of the locking mechanism at mounting/demounting of the sheet feeding cassette.

FIG. 6 is a diagram illustrating the configuration of a cassette mounting unit provided in a conventional image forming apparatus and also illustrating the configuration of a conventional sheet cassette demountably mounted in the conventional cassette mounting unit.

FIG. 7 is a diagram illustrating a state in which a lifting plate provided in the conventional sheet cassette is locked by a conventional locking mechanism.

Claims

1. A sheet feeding apparatus, in which a sheet accommodating unit is demountably provided in an apparatus body, the sheet accommodating unit having a sheet accommodating member, a lifting plate pivotably provided in the sheet accommodating member, and a pushing member configured to push the lifting plate toward a sheet feeding unit, the sheet feeding apparatus comprising: a locking mechanism configured to perform regulation of the lifting plate at a position to which the lifting plate descends against a pushing force of the pushing member, the locking mechanism including a pivotable locking member configured to regulate the lifting plate and a pivotable lock releasing lever configured to turn the locking member; anda lock release member configured to release the regulation of the lifting plate by the locking mechanism in response to mounting of the sheet accommodating unit in the apparatus body,wherein when the sheet accommodating unit is mounted in the apparatus body, the lock releasing lever is turned by the lock release member and turns the locking member to release the regulation of the lifting plate, andwherein when the sheet accommodating unit is drawn out of the apparatus body, the lock releasing lever is turned by the lock release member independently in a state in which the locking member regulates the lifting plate.

2. The sheet feeding apparatus according to claim 1, wherein the sheet accommodating member includes a regulation unit configured to regulate, when the locking member locks the lifting plate, turning of the locking member caused by the pushing force of the pushing member, wherein the locking member includes a catching part configured to catch the lifting plate, and an abutting part configured to abut when the lifting plate is locked, against the regulation unit of the apparatus body, andwherein the lock releasing lever includes an engaging part configured to engage, when moved in a lock releasing direction, with the locking member.

3. The sheet feeding apparatus according to claim 2, wherein the locking mechanism further includes: a first pushing member configured to push the abutting part of the locking member in a direction in which the abutting part of the locking member abuts against the regulation unit; anda second pushing member configured to push the lock releasing lever in a direction in which the engaging part of the lock releasing lever is engaged with the locking member.

4. The sheet feeding apparatus according to claim 3, wherein the first pushing member and the second pushing member are constituted by a same pushing member.

5. The sheet feeding apparatus according to claim 1, wherein the locking member is provided below the lifting plate and at a central part in a width direction perpendicular to a sheet feeding direction of the lifting plate.

6. The sheet feeding apparatus according to claim 1, wherein the apparatus body includes a guide member adapted to lower, when the sheet accommodating unit is drawn out, the lifting plate against the pushing force of the pushing member to a position at which the lifting plate is locked by the locking mechanism.

7. An image forming apparatus including a sheet feeding apparatus in which a sheet accommodating unit is demountably provided, the sheet accommodating unit having a sheet accommodating member, a lifting plate pivotably provided in the sheet accommodating member, and a pushing member configured to push the lifting plate toward a sheet feeding unit, the image forming apparatus also including an image forming unit configured to form an image on a sheet fed from the sheet feeding apparatus, the image forming apparatus comprising: a locking mechanism configured to perform regulation of the lifting plate at a position to which the lifting plate descends against a pushing force of the pushing member, the locking mechanism including a pivotable locking member configured to regulate the lifting plate, and a pivotable lock releasing lever configured to turn the locking member; anda lock release member configured to release the regulation of the lifting plate by the locking mechanism in response to mounting of the sheet accommodating unit in the apparatus body,wherein when the sheet accommodating unit is mounted in the apparatus body, the lock releasing lever abuts against the lock release member and turns to cause the locking member to turn to release the regulation of the lifting plate, andwherein when the sheet accommodating unit is drawn out of the apparatus body, the lock releasing lever is turned by the lock release member independently in a state in which the locking member regulates the lifting plate.