Outer Spindle Bending for Cylindrical Lock Positioning

Solution Overview

Problem

Cylindrical locks face challenges in manufacturing the outer spindle due to errors in welding, leading to incorrect positioning and increased costs, as well as time-consuming and costly welding procedures.

Innovation Solution

A cylindrical lock design featuring an inner and outer chassis with pivotable spindles and locking rings, where the outer spindle is formed by bending a metal sheet with restraining protrusions to ensure correct positioning and reduce assembly complexity, utilizing torsion springs and actuating grooves for efficient operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a C-shaped member is welded to the inner end of the outer spindle to prevent disengagement, then the outer spindle can be retained in the outer chassis, but the manufacturing complexity and cost increase due to welding operations

Engineering Contradiction:

Improveprevention of outer spindle disengagementVSAvoidmanufacturing complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The retaining function is merged into the outer spindle body by forming an enlarged-diameter portion directly on the spindle shaft through bending operations. This eliminates the separate C-shaped member and welding operation, while maintaining the disengagement prevention function.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The welding operation and separate C-shaped member are extracted from the assembly process. The retaining function is achieved through a purely mechanical feature (enlarged-diameter portion) formed during bending, removing the complex welding step from manufacturing.

Inventive Principle:

Principle #2Taking out (Extraction)

2Reliability

If a C-shaped member is welded to the inner end of the outer spindle, then the outer spindle can be retained in the outer chassis, but the manufacturing time and cost increase due to welding procedures

Engineering Contradiction:

Improveprevention of outer spindle disengagementVSAvoidmanufacturing efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The retaining function is merged into the outer spindle body by forming an enlarged-diameter portion directly on the spindle shaft through bending operations. This eliminates the separate C-shaped member and welding operation, while maintaining the disengagement prevention function.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The retaining feature (enlarged-diameter portion) is formed during the initial bending process before final assembly. This preliminary formation of the retaining feature eliminates the need for subsequent welding operations, improving manufacturing efficiency.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If welding is used to attach the C-shaped member, then the outer spindle can be retained in the outer chassis, but positioning errors occur leading to incorrect mounting position

Engineering Contradiction:

Improveprevention of outer spindle disengagementVSAvoidpositioning accuracy

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The retaining function is merged into the outer spindle body by forming an enlarged-diameter portion directly on the spindle shaft through bending operations. This eliminates the separate C-shaped member and welding operation, while maintaining the disengagement prevention function.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The retaining feature (enlarged-diameter portion) is formed during the initial bending process before final assembly. This preliminary formation of the retaining feature eliminates the need for subsequent welding operations, improving manufacturing efficiency.

Inventive Principle:

Principle #10Preliminary action

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 design allows for easier and cost-effective manufacturing of the outer spindle, ensuring correct positioning and reducing assembly time, while maintaining efficient operation and reducing wear on components.

Implementation Method 1

A torsion spring is mounted around the sleeve portion of the push ring. The torsion spring includes first and second tangs abutting two sides of the push leg.

Methodology Applied

Scientific EffectTorsion spring: Torsion Spring

Implementation Method 2

The abutment surface of the restraining protrusion abuts the abutment face of the outer lining, avoiding movement of the outer spindle away from the inner end of the outer chassis in the longitudinal direction.

Methodology Applied

Scientific EffectMechanical constraint: Mechanical Force

Data Source

PatentUS8449005B1Outer spindle for a cylindrical lock

Publication Date: 2013.05.28 I TEK METAL MFG

AI summary

A cylindrical lock includes a retractor (131) mounted between inner and outer operational devices (10, 12) and operably connected to a latch (779). The outer operational device (12) includes an outer chassis (305), an outer lining (353) mounted around the outer chassis (305), and an outer spindle (379) received in the outer chassis (305). The outer spindle (379) includes an inner end (391) received in a pivot hole (375) of the outer lining (353). A restraining protrusion (397) is formed on an outer periphery of the outer spindle (379) and abuts an abutment face (376) of the outer lining (353), avoiding movement of the outer spindle (379) away from the outer chassis (305) in a longitudinal direction while allowing pivotal movement of the outer spindle (379) in a correct position.