Reciprocating Saw Shoe Locking Lever Mechanism

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Solution Overview

Problem

Conventional reciprocating saws have complex and costly adjustment and lock mechanisms for the shoe assembly, requiring separate machining and slowing down operation as operators need to clamp the blade and lock the shoe separately, which increases downtime and manufacturing costs.

Innovation Solution

A single lever mechanism that pivotally moves between three positions to clamp and lock the saw blade and adjust/shoe height, utilizing a locking pin with arcuate grooves and detent rings for easy and efficient operation, allowing the shoe to be locked or unlocked with a single hand.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a complex post and plate mechanism with multiple slots and channels is used to adjust and lock the shoe, then the shoe can be locked in place, but the device complexity increases and manufacturing cost increases

Engineering Contradiction:
Improveshoe locking reliabilityVSAvoidadjustment mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the shoe adjustment mechanism and blade clamping mechanism into a single integrated lever system. The lever simultaneously performs both functions: adjusting the shoe position along the slot and clamping the blade against the shaft, eliminating the need for separate adjustment and locking mechanisms

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The lever is designed as a multi-functional component that can: (1) adjust the shoe position to different depths, (2) clamp the blade securely, and (3) lock both the shoe and blade in place. This universal component replaces multiple specialized parts in conventional designs

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

2Reliability

If separate mechanisms are used to clamp the blade and lock the shoe, then each function is performed reliably, but the ease of operation decreases and more time is required for adjustment

Engineering Contradiction:
Improveblade clamping and shoe locking reliabilityVSAvoidoperational convenience
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent merges the blade clamping operation and shoe locking operation into a single lever action. When the lever is moved to its locked position, it simultaneously clamps the blade and locks the shoe, allowing the operator to perform both functions with one motion rather than multiple separate steps

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If multiple separate mechanisms are used for clamping and locking, then each component can be optimized for its specific function, but the productivity decreases due to increased adjustment time

Engineering Contradiction:
Improvefunctional performanceVSAvoidwork pace
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The lever mechanism allows continuous adjustment of the shoe position while maintaining blade clamping. The operator can smoothly move the lever along the slot to adjust depth without interrupting the blade clamping function, enabling continuous workflow and reducing downtime between adjustments

Inventive Principle:
Principle #20Continuity of useful action

Data Source

PatentEP1738851B1Adjustable shoe assembly for a reciprocating saw
Publication Date: 2008.03.26 BLACK & DECKER CORP
  • EP1738851B1 patent drawingFigure 1
  • EP1738851B1 patent drawingFigure 2
  • EP1738851B1 patent drawingFigure 3~4

AI summary

A reciprocating saw (10) includes a locking mechanism for a shoe (14) of the reciprocating saw. The mechanism includes a lever (22) mounted on the saw body movable to a first position where the saw blade (12) is clamped in place. It also includes a lock pin with a body, a reduced circumference section, and a pin shoulder adjacent the reduced circumference section. The pin has a locked position where the pin shoulder abuts the shoe shoulder whereby the pin locks the shoe in place and an unlocked position where the shoe shoulder may translate through the clearance defined by the reduced circumference section. The lever urges the pin toward the locked position when the lever is in the first position.