Sheet Cassette Handle Locking to Prevent Pull-Out Jams
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Solution Overview
Problem
Existing image forming apparatuses with retractable sheet feeding cassettes face issues where pulling out the cassette during operation can interrupt the process, leading to potential jams, and existing locking mechanisms require a large handle protrusion, increasing the device's size.
Innovation Solution
A locking mechanism that restricts and releases the pulling out of the sheet feeding cassette by turning a handle housed within a recess on the outer cover, using a pin and lock member system that engages with an engagement portion on the apparatus main body, allowing for compact design and secure operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a locking mechanism uses a handle that moves forward in the pulling out direction, then the locking mechanism can reliably restrict and release the sheet feeding cassette, but the handle protrudes from the front surface and the size (depth) of the handle increases
Solution Approach 1:
Instead of moving the handle in the pulling out direction (forward), the invention inverts the operation direction by making the handle rotate about a rotational axis. The handle moves from an initial position extending forward to an operational position where it has rotated, allowing the locking mechanism to engage and disengage through rotational motion rather than linear motion in the pulling direction.
Solution Approach 2:
The invention changes the dimension of handle movement from linear (forward in pulling direction) to rotational (about a rotational axis). By making the handle rotatable about an axis that is not parallel to the pulling out direction, the mechanism achieves reliable locking through angular displacement rather than linear displacement, thereby reducing the protrusion depth.
2Ease of operation
If the handle is made longer to ensure reliable operation of the locking mechanism, then the locking can be more easily activated, but the apparatus's overall size increases
Solution Approach 1:
The invention inverts the operational approach by using rotational motion instead of linear extension. The handle rotates about a rotational axis to activate the locking mechanism, which allows sufficient operational leverage and reliability without requiring the handle to extend far forward, thus maintaining a compact apparatus volume.
Solution Approach 2:
The handle is designed with rotational freedom about a rotational axis, allowing it to dynamically change orientation from an initial extended position to an operational rotated position. This dynamic rotational capability provides adequate leverage for reliable locking operation without requiring a permanently long handle, optimizing both ease of operation and compactness.
Data Source
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AI summary
An image forming apparatus (1) includes a sheet feeding cassette (15) which is housed in an apparatus main body (3) in a retractable manner, and a locking mechanism (17) which restricts and releases a pulling out of the sheet feeding cassette (15) from the apparatus main body (3). The sheet feeding cassette (17) includes an outer cover (33), and a handle (45). The outer cover (33) has a recess (41) on an outer surface. The handle (45) is housed in the recess (41) so as to be turned outside from the outer surface, and turned outside by being gripped when the sheet feeding cassette (15) is pulled out from the apparatus main body (3). The locking mechanism (17) restricts and releases the pulling out of the sheet feeding cassette (15) from the apparatus main body (3) in conjunction with the turning of the handle (45).