Image Forming Apparatus Frame Caster Arrangement for Stability
Solution Overview
Problem
Conventional image forming apparatus frames with quadrangular bottom plates and casters attached to their corners are prone to deformation and instability when installed on uneven surfaces, leading to positional deviations and adverse effects on image quality.
Innovation Solution
A frame configuration with five casters attached to a quadrangular bottom plate, where three casters are strategically placed to balance the load and maintain stability, with the barycenter inside the triangle formed by these casters, and two additional casters positioned outside this triangle to prevent slanting and deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If three casters are attached near corners of a quadrangular bottom plate, then the bottom plate deformation is inhibited and positional accuracy is improved, but the apparatus becomes unstable when load is applied to uncovered corner regions
Solution Approach 1:
The bottom plate's support function is segmented into two distinct caster groups: three casters (first, second, third) form a triangular support base for primary stability and positional accuracy, while a fourth caster provides supplementary support for uncovered corner regions. This segmentation allows each caster group to specialize in different stability aspects without interfering with each other's function.
Solution Approach 2:
The patent applies partial action by having only three casters actively engaged on the installation face during normal operation, while the fourth caster remains partially engaged or ready to engage. This excessive action (having four casters instead of three) ensures that even when load is applied to uncovered regions, the fourth caster can provide necessary support to prevent slanting and maintain attitude stability.
2Ease of operation
If casters are attached one-to-one to the four corners of a quadrangular bottom plate, then the apparatus can be installed on flat surfaces, but the periphery of casters deforms on uneven surfaces causing positional deviation
Solution Approach 1:
The patent applies local quality by positioning casters at specific locations optimized for their function: three casters are placed near corners to provide stable triangular support, while the fourth caster is positioned to cover previously uncovered corner regions. This non-uniform, locally optimized caster arrangement allows the system to adapt to uneven surfaces while maintaining positional accuracy of supported members.
Solution Approach 2:
The fourth caster acts as a beforehand cushioning element that anticipates and prevents potential instability issues. By pre-positioning this caster to cover uncovered corner regions, the system prepares in advance for scenarios where load might be applied to areas not covered by the primary three-caster support, preventing deformation and positional deviation before they occur.
3Manufacturing precision
If only three casters are used for balanced installation, then positional accuracy is maintained, but the apparatus slants when unexpected load is applied to uncovered regions
Solution Approach 1:
The patent merges the functions of three-caster balanced support and four-caster corner coverage into a unified system. The first, second, and third casters merge to provide the primary triangular support for positional accuracy, while the fourth caster merges with this system to provide additional load-bearing capacity for uncovered regions, creating a hybrid support structure that achieves both precision and strength.
Solution Approach 2:
The caster arrangement forms a composite support structure where three casters create a triangular support zone optimized for positional accuracy, while the fourth caster creates an overlapping or adjacent support zone for enhanced load-bearing. This composite arrangement combines the advantages of both three-caster and four-caster configurations, achieving both precision and strength simultaneously.
Data Source
AI summary
A frame of an image forming apparatus, includes:a bottom plate having a bottom face whose shape is substantially quadrangular;a first caster;a second caster;a third caster attached near a second side of the bottom face, the third caster being disposed such that a barycenter of the image forming apparatus is located inside a triangle formed by imaginary lines connecting the first caster, the second caster, and the third caster; anda fourth caster attached to a region outside the triangle, the fourth caster being provided closer to the second side than the barycenter, whereinin a case where the image forming apparatus is installed on the installation face which is flat, the first caster, the second caster, and the third caster are installed on the installation face, and the fourth caster is located away from the installation face.