Stapler Lever Mechanism for Hand Force Synchronization

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Solution Overview

Problem

Existing stapler designs fail to synchronize the force produced by a user's hand with the force required to tension the elastic member, resulting in inefficient staple driving due to a linear increase in tensioning force that does not match the non-linear force production of a clenched hand.

Innovation Solution

The stapler design optimizes the articulated arrangement by setting the first distance 1.2-1.6 times greater than the second distance, with a specific ratio of 1.4, and an angle of 58°-68° between the distance lines, allowing for improved synchronization between hand force and elastic member tensioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the elastic member is tensioned with a linear increase in force, then the structure is simple, but the synchronization with hand force production is poor

Engineering Contradiction:
Improvestructure simplicityVSAvoidsynchronization with hand force
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The patent changes the geometric parameters of the articulated arrangement, specifically setting the first distance to 1.2-1.6 times the second distance and the angle between distance lines to 58°-68°, to transform the linear force increase into a non-linear force curve that matches hand clenching characteristics

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces an articulated arrangement with lever and articulated arm that dynamically transforms the force application during the stapling operation, allowing the force increase to follow a non-linear curve matching hand force production rather than a simple linear progression

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If the first distance is increased to 1.2-1.6 times the second distance, then the synchronization of force production is improved, but the device complexity increases

Engineering Contradiction:
Improveforce synchronizationVSAvoidarticulated arrangement configuration
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent optimizes specific geometric parameters (distance ratio of 1.2-1.6 and angle of 58°-68°) to achieve the desired force synchronization, demonstrating how precise parameter adjustment can improve performance while keeping the overall structure relatively simple

Inventive Principle:
Principle #35Parameter changes

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

This configuration enhances the synchronization of hand force and elastic member tension, leading to more efficient staple driving by aligning the force increase with the natural force curve of a clenched hand, improving the stapler's operational efficiency.

Implementation Method 1

an elastic member (7) connected to the driver (9), which is intended to drive a stapile (4) into a workpiece (6)

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a lever (13), which is coupled to the body (2) rotatably via a first coupling shaft (14) and which has a long arm (15) and a short arm (16)

Methodology Applied
Scientific EffectLever: Lever

Data Source

PatentEP2819811B1Stapler with arrangement for tensioning an elastic member forming part of the stapler
Publication Date: 2017.09.13 ISABERG RAPID AB
  • EP2819811B1 patent drawingFigure 1
  • EP2819811B1 patent drawingFigure 2
  • EP2819811B1 patent drawingFigure 3

AI summary

Stapler (1) for driving staples (4) into a workpiece (6), comprising a body (2), an elastic member (7) connected to a driver (9) and an articulated arrangement (12) for tensioning of the member (7) comprising a lever (13) with a long arm (15) and a short arm (16) coupled rotatably to the body by a first coupling shaft (14), an articulated arm (17) coupled rotatably to the body by a second coupling shaft (18) and connected to the member (7) in a force-influencing manner, an intermediate joint (19) with a third coupling shaft (20) assigned rotatably to the short arm (16) at a first distance (a) from the first coupling shaft and assigned rotatably to the articulated arm (17) with a fourth coupling shaft (21) at a second distance (b) from the third coupling shaft (20), the first distance has the distance line (a) and the second distance has the distance line (beta), which form the angle (gamma) between themselves, the member (7) is tensioned in that the lever (13) is rotated (N) about coupling shaft (14) from a starting position to an end position, due to which the lever via the intermediate joint causes the articulated arm to rotate (R) about the coupling shaft and tension the member (7) by guiding this from a first neutral untensioned position to a second tensioned position, wherein the first distance (a) is 1.2- 1.6 times greater than the second distance (b).