Rail Attachment Cam Mechanism for Controlled Clamping Force

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing rail locking devices for securing loads are prone to breakage due to inadequate force gauging, can clamp incorrectly, and may not be sufficiently attached, leading to unreliable use, especially under heavy loads.

Innovation Solution

A rail locking device with a cam mechanism that converts rotational movement into axial translation of a support plate, ensuring controlled tightening and preventing breakage, combined with a guide slider and indexing pins for precise positioning, allowing a single rotation for attachment, clamping, and locking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a lever arm is used to press the anvil screw under the wings of the rail, then the clamping force is increased, but the device may break due to excessive force or be insufficiently tight due to insufficient force

Engineering Contradiction:
Improveclamping forceVSAvoidattachment reliability
Core Design Contradiction:
ForceVSReliability

Solution Approach 1:

The cam mechanism transforms the rotational movement of the shaft into controlled axial translation of the support plate, converting a rotational input into a linear output with a specific force-displacement characteristic. This allows the clamping force to be precisely controlled through the cam profile geometry, eliminating the unpredictability of manual lever arm operation.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If the anvil screw is rotated manually, then the device can be positioned along the rail, but the device may move to the wrong position during rotation

Engineering Contradiction:
Improvepositioning easeVSAvoidpositioning precision
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The guide slider with indexing lobes and the stud provide a mechanical feedback system that gives the operator tactile and visual confirmation of the correct positioning. The stud can only be inserted when the guide slider is properly aligned with the indexing lobes at the desired position, preventing incorrect placement.

Inventive Principle:
Principle #23Feedback

3Ease of operation

If the anvil screw is not turned sufficiently before lowering the lever, then the device may be insufficiently attached and unhook under load

Engineering Contradiction:
Improveoperation simplicityVSAvoidattachment security
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The cam mechanism is designed so that the axial translation of the support plate toward the lock occurs automatically and progressively as the shaft is rotated into its final position. This preliminary action ensures the lock is properly engaged against the rail flanges before the support plate applies full clamping force, guaranteeing secure attachment.

Inventive Principle:
Principle #10Preliminary action

4Productivity

If a single rotation is used for attachment and locking, then the operation is simplified and rapid, but precise control of tightening force is required

Engineering Contradiction:
Improveattachment speedVSAvoidtightening control
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The cam acts as an intermediary mechanism between the rotational input (shaft rotation) and the linear output (support plate translation). The cam profile is specifically designed to provide a controlled force-displacement relationship during the single rotation, automatically regulating the tightening force to achieve proper clamping without requiring precise operator control.

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

The solution enables simple, rapid, and reliable attachment and locking of loads, providing controlled tightening and preventing involuntary clamping, ensuring secure attachment even under heavy loads.

Implementation Method 1

the locking member has a cam adapted to move the backing plate axially relative to the rotating shaft when the rotating shaft is rotated in either direction

Methodology Applied
Scientific EffectCam mechanism: Cam

Data Source

PatentEP3122594B1Device for attachment to a rail
Publication Date: 2018.05.09 A RAYMOND & CO SCS
  • EP3122594B1 patent drawingFigure 1
  • EP3122594B1 patent drawingFigure 2~3
  • EP3122594B1 patent drawingFigure 4a~4b

AI summary

An attachment device for attaching to a generally channel-section rail having rims forming a channel is provided. The device comprises a latch for inserting into the inside of the channel and for being retained therein by the rims of the rail, and a locking member for locking the latch in the rail. The locking member comprises a rotary shaft secured to the latch and extending axially through a bearing plats for resting on the top of the channel. The locking member also includes a cam adapted to move the bearing plate axially relative to the rotary shaft when the rotary shaft is turned in one direction or the other. The bearing plate comes closer to the latch when the rotary shaft is turned in one direction of rotation and the bearing plate moves away from the latch when the rotary shaft is burned in the opposite direction.