Roller Apparatus Cable End Stiffness via Arc-Shaped Key
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Solution Overview
Problem
Conventional roller apparatuses for sliding doors experience insufficient stiffness in the cable end, leading to stress concentration and potential cracking, which shortens the maintenance cycle.
Innovation Solution
A roller apparatus design featuring a bracket with a pin protruding at a right angle, a cable end with an arc-shaped insertion hole, and a bush with a notch and abutting portion to distribute stress and prevent direct contact, enhancing stiffness without increasing the cable end's constitution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a rectangular key with right angles is used in the cable end, then the cable end can be retained in the pin, but stress concentrates on the four corners leading to insufficient stiffness and potential cracking
Solution Approach 1:
The patent replaces the rectangular key with an arc-shaped key that has a curved profile matching the arc-shaped inner wall of the insertion hole. This curvature eliminates the sharp corners that cause stress concentration, distributing stress more evenly along the arc shape. The arc-shaped key maintains the retention function while significantly improving stiffness and preventing cracking, thus extending the maintenance cycle.
2Ease of manufacture
If the cable end structure is simplified, then manufacturing becomes easier, but stiffness and stress distribution are insufficient
Solution Approach 1:
The arc-shaped key design is inherently more suitable for molding processes compared to complex rectangular structures with precise right angles. The curved geometry can be formed more easily in injection molding, reducing manufacturing complexity while simultaneously providing superior stress distribution and stiffness characteristics.
3Device complexity
If the pin and cable end come into direct contact, then the structure is simpler, but stress concentration occurs and the maintenance cycle is shortened
Solution Approach 1:
The patent introduces a bush as an intermediary component between the pin and the cable end. The bush contains the arc-shaped insertion hole that receives the arc-shaped key, mediating the interaction between the pin and cable end. This intermediary structure prevents direct contact and stress concentration while maintaining a relatively simple overall constitution, thereby extending the maintenance cycle.
Data Source
AI summary
An object of the present invention is to enhance stiffness of a cable end without increasing the size of the cable end. A first retaining protrusion (35b) is provided on the tip side of a second roller pin (35) so as to protrude from the second roller pin (35) in a radially outward direction of the second roller pin (35), a cable end (40) is formed with an insertion hole (43) including an arc-shaped second inner wall (43b), the first retaining protrusion (35b) being allowed to pass through the insertion hole (43). A bush (50) is provided with: a notch (51a) which exposes the second inner wall (43b) to the outside, the first retaining protrusion (35b) being allowed to pass through the notch (51a); and a cylindrical main body (51) which covers a first inner wall (43a), the first retaining protrusion (35b) abutting on the main body (51) in a radial direction of the second roller pin (35).