Bi-Directional Cable Grab Frame for Upward Fall Arrest
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Solution Overview
Problem
Existing cable grab devices for fall protection are ineffective when forced to articulate in the upward direction, failing to arrest the person's fall as they do not contact the cable, thus requiring an improved design that functions bidirectionally.
Innovation Solution
A cable grab device with a bi-directional articulating frame that includes a channel for cable retention, pivot members for braking, and a biasing mechanism to ensure contact with the cable regardless of the device's orientation, featuring a slot for secure attachment and engagement in both downward and upward movements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the cable grab device is designed with a unidirectional articulating frame, then the device structure is simple, but the device fails to contact the cable when forced to articulate in the upward direction, making it ineffective for fall arrest
Solution Approach 1:
The patent applies inversion by designing the articulating frame with slots that allow the cable to engage the pivot members regardless of the direction of movement. Instead of relying on a unidirectional mechanism, the frame geometry is inverted or modified so that the same structural elements can effectively contact and brake the cable in both downward and upward articulation, thereby resolving the contradiction between reliability and complexity.
2Ease of operation
If the cable grab device allows free movement in both directions, then the ease of operation is improved, but the device cannot arrest the fall when moved in the upward direction
Solution Approach 1:
The patent applies dynamics by incorporating slots in the articulating frame that enable the pivot members to dynamically adjust their position relative to the cable based on the direction of movement. The slots allow the cable to engage the pivot members during both downward and upward movement, ensuring that the braking function is activated dynamically regardless of movement direction, thus maintaining reliability while preserving ease of operation.
3Reliability
If the device uses a fixed pivot member design, then the manufacturing precision is easier to achieve, but the device cannot ensure cable contact in all orientations
Solution Approach 1:
The patent applies segmentation by dividing the pivot member into multiple functional segments or components, where at least one pivot member includes a slot that allows relative movement between segments. This segmentation enables the pivot member to adapt its configuration based on movement direction, ensuring cable contact in all orientations without requiring extremely tight manufacturing tolerances on the entire assembly, thus resolving the contradiction between reliability and manufacturing precision.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Ensures effective fall arrest in both downward and upward directions by ensuring the device contacts the cable, providing enhanced safety and reliability in fall protection scenarios.
Implementation Method 1
a biasing mechanism to ensure contact with the cable regardless of the device's orientation
Implementation Method 2
the first end of the first pivot member and the first end of the second pivot member contacts and/or bears against the cable (C), which brakes or stops the movement of the cable grab device (200) in the downward direction
Data Source
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AI summary
A fall protection device or cable grab device for use with a generally vertically-extending cable, comprising: an articulating frame comprising: (i) a plurality of members; (ii) a channel configured to receive and retain the cable; and (iii) an attachment member opening extending through at least a portion of the articulating frame and configured to facilitate attachment of an attachment member to the cable grab device; wherein, when the frame is articulated in a generally downward (or first) direction, and at a specified point, at least a portion of at least one of the plurality of members contacts the cable and brakes movement of the cable grab device; wherein, when the frame is articulated in a generally upward (or second) direction, and at a specified point, at least a portion of at least one of the plurality of members contacts the cable and brakes movement of the cable grab device.