Pneumatic-Hydraulic Cylinder Piston Rod Interlock Mechanism

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Solution Overview

Problem

Existing pneumatic-and-hydraulic cylinders lack a reliable interlock mechanism for safe cooperation with industrial fume-extraction flap valves, which is crucial for precise control of opening and closing operations.

Innovation Solution

A pneumatic-and-hydraulic cylinder design featuring interlocked piston rods with locking units on both covers, utilizing steel balls and helical springs for secure engagement, and a rotatable unlocking ring with limited turning angle, connected through springing means for controlled unlocking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a locking unit with steel balls and helical springs is implemented in the piston rod, then the reliability of the interlock mechanism is improved, but the device complexity increases

Engineering Contradiction:
Improvereliability of interlock mechanismVSAvoidcomplexity of locking unit
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking unit is divided into distinct functional components: steel balls for locking, helical springs for actuation, and a rotatable unlocking ring for control. This segmentation allows each component to perform its specific function reliably while maintaining overall system manageability despite the increased complexity.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If a rotatable unlocking ring with limited turning angle is added to control the locking mechanism, then the precision of control is improved, but the ease of operation is reduced

Engineering Contradiction:
Improveprecision of controlVSAvoidease of unlocking
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The unlocking ring is designed with a limited turning angle that operates in discrete periodic steps. Each rotation step corresponds to a specific unlocking state, providing precise control over the piston rod's position while maintaining simple manual operation through rotational motion.

Inventive Principle:
Principle #19Periodic action

3Reliability

If locking units are installed on both front and rear covers of the cylinder, then the safety of the system is improved, but the manufacturing cost increases

Engineering Contradiction:
Improvesafety of systemVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

Identical locking units are implemented on both the front and rear covers of the cylinder, merging the same reliable locking mechanism into both positions. This symmetric design ensures uniform safety performance while allowing for standardized manufacturing of the locking units, which can reduce per-unit costs through economies of scale.

Inventive Principle:
Principle #5Merging (Combining)

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

Ensures safe and precise operation of fume-extraction flap valves by providing a reliable interlock mechanism that securely engages and disengages the piston rod, enhancing the control systems' reliability and safety.

Implementation Method 1

helical springs that are based in the lid covering the upper end of the sleeve body

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

piston in tight mounting on piston rod and in the sleeve body seat, with steel balls located in-between and adhering to piston rod surface, said piston rod being pressed from above with helical springs

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 3

unlocking ring being connected with said body through springing means so that its turning angle is limited

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 4

springing means with the unlocking ring are shielded with cover separably connected with that ring

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP1977116B1Pneumatic-and-hydraulic cylinder with piston rod interlock
Publication Date: 2011.03.09 REWA
  • EP1977116B1 patent drawingFigure 1
  • EP1977116B1 patent drawingFigure 2
  • EP1977116B1 patent drawingFigure 3~4

AI summary

Pneumatic-and-hydraulic cylinder with interlock of its piston rod consisting of cylinder with two end covers, internal piston rod provided with piston moving between said covers as well as with eye bolt, both said covers being interconnected with pipe connector through angular connectors, wherein one end of the cylindrical sleeve (1) is provided with tight-mounted front cover (4) with locking unit (6) and at the other end said sleeve is provided with tight-mounted rear cover (7) with locking unit (8). Both the front cover (4) and the rear cover (7) are provided with locking units of similar design, whereas the locking unit (6) of said front cover (4) consists of plunger (23) mounted tight on piston rod (3) and in the seat of sleeve body (3CB), with steel balls (27) located in-between and adjacent to the surface piston rod (3), which is pressed from above with helical springs (35) that are based in the lid (29) covering the upper end of the sleeve body (1) as well as the unlocking ring (13), mounted rotatably on its external surface, said unlocking ring (13) being connected with said body through springing means (19) so that its turning angle is limited.