Adjustable Dumbbell Self-Locking Cam Mechanism

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Solution Overview

Problem

Conventional weight-lifting instruments are bulky, expensive, and difficult to maintain, with simple instruments requiring cumbersome and unsafe clamping mechanisms, limiting their use for aerobic exercises due to the need for frequent weight assembly and disassembly, and adjustable dumbbells lack self-locking mechanisms, leading to weight slippage during use.

Innovation Solution

An adjustable dumbbell with a self-locking mechanism, comprising a weight-lifting shaft with cam plates and adjustment knobs, and a holder with grooves and protrusion blocks, allowing for various weight options and secure attachment, enabling safe and easy assembly and storage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If simple weight-lifting instruments use clamping rings or clips to fix weights onto the shaft, then weights can be secured, but the connection becomes troublesome and unsafe when worn or broken

Engineering Contradiction:
Improveweight fixation safetyVSAvoidconnection convenience
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The invention extracts the clamping function from separate clamping rings or clips and integrates it into the weight plates themselves through cam mechanisms. The cam plates and cam lobes are built into the weight plate structure, eliminating the need for separate clamping components that can wear or break.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention merges the weight plate, cam mechanism, and locking function into a single integrated assembly. The weight plate includes integrated cam plates with cam lobes that automatically engage with the shaft, combining multiple functions (weight provision, clamping, and locking) into one component.

Inventive Principle:
Principle #5Merging (Combining)

2Adaptability or versatility

If weights are made removable and adjustable on the shaft, then weight selection flexibility is improved, but assembly becomes tedious requiring carrying, collimating, sliding and fixing weights

Engineering Contradiction:
Improveweight selection flexibilityVSAvoidassembly time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The invention prepares the cam mechanisms in advance within the weight plates and holder. The cam lobes are pre-positioned and the holder contains guide structures that automatically align weights with the shaft during insertion, eliminating the need for manual collimation and alignment during assembly.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention uses dynamic cam mechanisms that automatically engage and lock weights onto the shaft through rotational motion. The cam lobes rotate into engagement positions as weights are inserted, providing automatic locking without requiring manual fixing operations.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If adjustable dumbbells lack a self-locking mechanism, then the structure is simpler, but weights risk slipping off during use

Engineering Contradiction:
Improvestructure simplicityVSAvoidweight retention safety
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The invention implements a self-locking mechanism where the cam mechanisms automatically engage and lock weights onto the shaft without requiring separate locking operations. The cam lobes self-engage with the shaft grooves through their own rotational motion, providing automatic self-locking functionality.

Inventive Principle:
Principle #25Self-service

4Adaptability or versatility

If frequent weight assembly and disassembly is required for simple weight-lifting instruments, then weight adjustment is possible, but continuous aerobic exercise cannot be maintained due to interruption time

Engineering Contradiction:
Improveweight adjustment capabilityVSAvoidexercise continuity
Core Design Contradiction:
Adaptability or versatilityVSDuration of action of moving object

Solution Approach 1:

The invention pre-positions multiple weight plates with different weight configurations in the holder. Users can quickly swap between pre-configured weight sets by simply removing one weight plate and inserting another, eliminating the need for assembly during exercise transitions.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention uses dynamic quick-release mechanisms with cam-based locking that allow weight plates to be rapidly exchanged. The cam mechanisms automatically engage upon insertion, enabling weight changes to be completed in seconds rather than minutes, maintaining exercise continuity.

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 adjustable dumbbell provides a safe, reliable, and space-efficient solution for weightlifting, allowing for continuous aerobic exercise by eliminating the need for frequent weight adjustments and ensuring weights remain securely attached during use.

Implementation Method 1

The weigh-lifting shaft comprises a grip handle, a rotatable spindle extending through the grip handle, several cam plates assembled through both ends of the rotatable spindle

Methodology Applied
Scientific EffectCam mechanism: Cam

Implementation Method 2

The holder cooperates with the weigh-lifting shaft to form a self-locking mechanism. The weigh-lifting shaft comprises cam plates and adjustment knobs, and a holder with grooves and protrusion blocks, allowing for various weight options and secure attachment

Methodology Applied
Scientific EffectSelf-locking mechanism: Mechanical Force

Data Source

PatentEP1837057B1Adjustable dumbbell
Publication Date: 2010.11.17 ORANGE INT TRADING TIANJIN
  • EP1837057B1 patent drawingFigure 1
  • EP1837057B1 patent drawingFigure 2~3
  • EP1837057B1 patent drawingFigure 4~5

AI summary

An adjustable dumbbell comprising: a plurality of weights each having a central hole and a slot extending through the central hole, a weight-lifting shaft, and a holder. The holder cooperates with the weight-lifting shaft to form a self-locking mechanism. The weight-lifting shaft comprises a grip handle, a rotatable spindle extending through the grip handle, several cam plates assembled through both ends of the rotatable spindle, and adjustment knobs assembled on both ends of the weight-lifting shaft. The out diameter of the cam plate is configured to engage the central hole of the weights. The holder comprises grooves and protrusion blocks, wherein the protrusion blocks cooperate with the pins on the weight-lifting shaft to form a self-locking means.