Segmented Brake Button for Quiet Leash Winding

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing dog leashes with braking devices experience noise and chattering issues during the winding process due to the design of the brake button, which requires constant manual intervention to prevent the rope from unwinding, making it difficult to manage the leash effectively during retrieval.

Innovation Solution

A two-part brake button design where the upper part is actuated by the user and the lower part is pivotably connected, allowing the rope to wind up without noise by pivoting away from the pulley projections, utilizing friction to maintain engagement and prevent unwinding, with a spring-dimensioned frictional force ensuring secure winding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the brake button is designed to strike against projections on the pulley to prevent unwinding, then the braking function is reliable, but noise and chattering occur during the winding process

Engineering Contradiction:
Improvebraking functionVSAvoidnoise and chattering
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The brake button is divided into two separate parts: an upper part that is actuated by the user and a lower part that interacts with the pulley. This segmentation allows the lower part to pivot and engage with projections only when needed for braking, while disengaging during winding to eliminate noise and chattering.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The lower part of the brake button is made pivotable rather than fixed, allowing it to dynamically adjust its position. During winding, it pivots away from the pulley projections to avoid contact and noise; during braking, it engages with the projections to provide reliable stopping.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the brake button is constantly pressed to prevent rope unwinding, then the rope remains controlled, but manual intervention is required continuously making retrieval difficult

Engineering Contradiction:
Improverope controlVSAvoidmanual intervention
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The brake button is designed to engage automatically with the pulley projections when the rope tension increases during retrieval. The user only needs to press the button to initiate braking, after which the mechanism self-regulates based on rope tension, eliminating the need for constant manual pressing.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The brake mechanism responds to feedback from rope tension. When the dog pulls on the rope during retrieval, the increased tension automatically triggers the brake button to engage with the projections, providing controlled stopping without requiring the user to continuously monitor and adjust the brake.

Inventive Principle:
Principle #23Feedback

3Reliability

If the brake button design causes chattering during winding, then the braking engagement is frequent, but wear increases and operation becomes less smooth

Engineering Contradiction:
Improvebraking engagementVSAvoidwear and smooth operation
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

By separating the actuation function (upper part) from the engagement function (lower part), the design allows the lower part to smoothly pivot into and out of engagement with projections without the chattering that occurs when a single rigid button is forced to perform both functions simultaneously.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The pivotable lower part enables smooth, controlled engagement with the pulley projections by rotating into position rather than being forced into contact. This dynamic movement eliminates chattering and reduces wear on both the brake button and pulley surface.

Inventive Principle:
Principle #15Dynamics

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

The solution allows for quiet and efficient winding of the rope while keeping the brake button pressed, reducing the need for constant manual intervention and minimizing wear, ensuring reliable operation with reduced noise and improved handling during leash management.

Implementation Method 1

the rope can be unwound from the pulley against the force of a spring and due to the force of the spring can be wound onto the rope pulley

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 2

the lower part rests rubbing against the rope pulley around which the lower part can pivot by rotating the pulley in the winding direction

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP1972193B1Mechanical retractable and extendable leash for animals
Publication Date: 2012.03.21 FLEXI BOGDAHN TECHN
  • EP1972193B1 patent drawingFigure 1
  • EP1972193B1 patent drawingFigure 2a~2e
  • EP1972193B1 patent drawingFigure 3a~3c

AI summary

Braking system comprises a braking button with an upper part (20) protruding from a lead housing (12) and a lower part (21) for interacting with a cable pulley (11) and pivoting on the upper part. The lower part pivots in the winding direction (15) of the cable so that unwinding of the cable from the cable pulley is prevented in the active position of the braking button. Preferred Features: The lower part of the braking button is connected to the upper part when pushed in the pressing direction. The lower part pivots on a pin (24) in or with a longitudinal hole (25) and slides with the upper part.