Retractable Pet Leash Single Pushbutton Cam Control

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Solution Overview

Problem

Existing retractable pet leashes require multiple control units for dual braking and blocking operations, leading to user inconvenience and potential confusion.

Innovation Solution

A dual control system integrated into a single pushbutton on the winder, utilizing a cam system for gradual braking and subsequent complete blocking of the cord through interference with the winding drum's toothing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple control units are used for dual braking and blocking operations, then the functionality is complete, but the user convenience deteriorates and operational confusion increases

Engineering Contradiction:
Improvedual braking and blocking functionalityVSAvoiduser convenience
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent combines multiple control units into a single integrated pushbutton mechanism that performs both braking and blocking operations. The single control unit incorporates a cam system with multiple lobes that sequentially engage different braking surfaces and blocking mechanisms, eliminating the need for separate control units while maintaining complete dual-functionality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single pushbutton control unit is designed to perform multiple functions: gradual braking, complete blocking, and resetting. By integrating these functions into one universal control mechanism with a multi-lobe cam system, the patent achieves both versatility and ease of operation, allowing the user to control all leash functions through a single interface.

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

2Ease of operation

If a single pushbutton is used for both braking and blocking, then the ease of operation is improved, but the device complexity increases

Engineering Contradiction:
Improvesingle control pushbuttonVSAvoidcontrol mechanism complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The control mechanism is segmented into distinct functional components within the single pushbutton: a multi-lobe cam system with different lobes for braking and blocking, separate spring mechanisms for each function, and designated engagement surfaces. This segmentation allows complex functions to be managed through modular, organized sub-components rather than a monolithic complex mechanism.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cam system acts as an intermediary mechanism that translates the simple pushing motion into complex sequential operations. The cam's lobes sequentially engage different braking surfaces and blocking mechanisms, mediating between the user's simple input and the complex multi-step control sequence required for braking and blocking operations.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enables simple and effective dual-function braking and blocking of the leash cord with a single pushbutton, enhancing user convenience and operational clarity.

Implementation Method 1

a spring (19) which acts on the pushbutton (14) and which enables the pushbutton (14) to be returned into the initial position

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a brake pad (23) which is pressed, depending on the pressing force applied by the user, against a relatively smooth surface (28) of the winding drum (12), with the resulting gradual braking of the cord

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 3

a toothing (34) formed at the end of the control (13) and which, when pressed against a toothing (33) formed on the front wall, makes it possible to completely block the cord

Methodology Applied
Scientific EffectMechanical interlocking: Mechanical Fastener

Data Source

PatentEP3021662B1Retractable pet leash
Publication Date: 2017.05.03 FERPLAST SRL
  • EP3021662B1 patent drawingFigure 1
  • EP3021662B1 patent drawingFigure 1A~1C
  • EP3021662B1 patent drawingFigure 2

AI summary

A retractable leash (10) comprises an internally hollow casing or frame made from metal or synthetic material, forming a handle (11) with which to grip, control and hold the leash, a winding drum (12) subjected to the action of first elastic means and wound around which is a cord or tape whose end is provided with means for fixing the cord or tape to the collar of a pet; said winding drum (12) having a continuous circular surface (28) and a series of openings (30) arranged radially and defined by a series of teeth (29), also comprising a first braking mechanism (21, 23) in which a pad (23) acts by friction against said circular surface (28) of said winding drum (12) and a second blocking mechanism (25, 15, 16) in which an element (16) pushed by second elastic means (19) enters one of said openings (30) causing the rotation of said winding drum (12) to stop. The leash also comprises a control (13) provided with a manually activated pushbutton (14) subjected to the action of third elastic means (19). Said control (13) is equipped with a cursor (15) fixed to said pushbutton (14), mobile linearly between two predetermined positions, and which acts on one hand on said braking mechanism so the pressure on the pushbutton (14) determines the progressive interference of said pad (23) with said circular surface (28), and on the other on a component for the release (25, 27) of the blocking mechanism which is activated by continued pressure on said pushbutton (14), causing immediate movement of the element (16) pushed by said second elastic means inside one of said openings (30).