Rope Pick-Up Locking Pawl Mechanism for Compact Multi-Position Control

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Solution Overview

Problem

Existing holding and releasing mechanisms for stepping switches, used in bicycles, are not compact enough and do not allow for a large number of operating positions, and they lack simplicity and adjustability.

Innovation Solution

A holding and releasing mechanism with a toothed disc arrangement featuring two groups of teeth in orthogonal planes, an adjustable locking pawl with locking and securing projections, and a design that allows for a wide angular range, enabling a compact and space-saving solution with multiple operating positions, including adjustable actuation positions for the cable.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a conventional holding and releasing mechanism with single-plane teeth is used, then the structure is simple, but the number of operating positions is limited and the mechanism is not compact

Engineering Contradiction:
Improvenumber of operating positionsVSAvoidstructure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies dimensionality change by arranging teeth on the toothed disc in multiple planes (at least two different planes) rather than a single plane. This allows the locking pawl with its multiple projections to engage with teeth at different angular positions around the rotation axis, thereby increasing the number of available operating positions without proportionally increasing the radial or axial dimensions of the mechanism, achieving a compact design with enhanced versatility.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent segments the toothed disc into multiple functional zones by placing teeth in different planes at different angular positions. Each plane can be dedicated to specific functions (e.g., one plane for normal operating positions, another for intermediate or limit positions), allowing independent optimization of each segment's purpose while collectively providing numerous distinct operating positions.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If the angular range of the toothed disc arrangement is increased to allow more operating positions, then more positions are available, but the mechanism becomes larger and less compact

Engineering Contradiction:
Improvenumber of operating positionsVSAvoidmechanism volume
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

By utilizing multiple planes for tooth arrangement, the patent effectively packs more operating positions into a smaller angular range. The vertical separation between planes allows teeth to be positioned at different angular locations without increasing the radial footprint, thereby increasing the number of operating positions while maintaining a compact mechanism volume.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent employs a nested arrangement where teeth in different planes are vertically stacked relative to the rotation axis. This nesting allows the locking pawl to access teeth at different angular positions by engaging with different planes, effectively nesting multiple levels of operating positions within a compact radial and axial envelope.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Adaptability or versatility

If a locking pawl with multiple projections is used to engage teeth in different planes, then more operating positions are achieved, but the pawl structure becomes more complex

Engineering Contradiction:
Improvenumber of operating positionsVSAvoidlocking pawl structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The locking pawl is designed as a multi-functional component with multiple projections that can engage with teeth in different planes. Each projection serves a specific function (e.g., one for normal operation, another for limit positioning), but all are integrated into a single pawl structure that rotates as one unit, providing universal holding capability across multiple operating positions without requiring separate locking mechanisms for each plane.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges multiple locking functions into a single integrated locking pawl structure. Instead of having separate locking mechanisms for each plane, the multiple projections on one pawl are combined to provide locking engagement with teeth across different planes, simplifying the overall structure by consolidating what could have been multiple independent components into one unified element.

Inventive Principle:
Principle #5Merging (Combining)

4Measurement precision

If intermediate positions are added between operating positions for gradual cable release, then control precision is improved, but the mechanism complexity increases

Engineering Contradiction:
Improvecontrol precisionVSAvoidmechanism complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent utilizes the vertical dimension (different planes) to accommodate both operating position teeth and intermediate position teeth. By arranging intermediate position teeth in a different plane from the main operating position teeth, the mechanism achieves finer control resolution without adding radial or horizontal complexity, as the intermediate positions are nested in the vertical stacking of tooth planes.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP2842860B2Holding and release mechanism for holding and releasing a rope pick-up device
Publication Date: 2022.07.27 SRAM
  • EP2842860B2 patent drawingFigure 1
  • EP2842860B2 patent drawingFigure 2
  • EP2842860B2 patent drawingFigure 3

AI summary

A holding and releasing mechanism (29) is provided for holding and releasing a rope receiving device (46), for example, a step switch (20'), comprising a toothed disc arrangement (24) integrally belonging to or rotationally fixed to or connectable to the rope receiving device (46), rotatable about a first axis (X), which has a plurality of teeth (1-10, 26) on its outer circumference; an adjustable locking pawl (28), preferably pivotable about a second axis (Y), which, in a first position, in particular a first pivot position, engages with a locking projection (30) with a tooth (1-10) of the plurality of teeth associated with the respective first rotation position, serving as a locking tooth, when the toothed disc arrangement (24) is in various first rotation positions, in order to hold or stop the toothed disc arrangement (24) and thus the rope receiving device (46) in the respective first rotation position.and which, in a second position, in particular a second pivot position, engages with a locking projection (32) with a tooth (26) of the plurality of teeth assigned to the respective second rotation position, in order to hold or retain the toothed disc arrangement (24) and thus the rope receiving device (46) in the respective second rotation position, wherein the first rotation positions correspond to actuation positions of the actuating rope (48) or a subset of these actuating positions and the second rotation positions correspond to intermediate positions of the actuating rope (48) when the actuating rope (48) is transferred between adjacent actuating positions by releasing the actuating rope (48).