Double Piston Hydraulic Damper Eliminates Fluid Leakage in Turnstiles

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Solution Overview

Problem

Existing turnstile mechanisms suffer from hydraulic fluid loss due to sliding piston rods in cylinder-piston mechanisms, leading to maintenance issues and reduced lifespan, and rotary dampers face complexity and temperature compensation challenges.

Innovation Solution

A double cylinder-piston mechanism with a translating piston, where two pistons reciprocate simultaneously to generate translational motion within the mechanism, eliminating the need for a piston rod and minimizing hydraulic fluid loss, and a cam or crank mechanism actuates the pistons for controlled damping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a sliding piston rod is used in the cylinder-piston mechanism, then the damping function is achieved, but hydraulic fluid is lost leading to maintenance issues and reduced lifespan

Engineering Contradiction:
Improveturnstile lifespanVSAvoidhydraulic fluid loss
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The invention extracts and eliminates the piston rod from the hydraulic damper system. Instead of using a traditional cylinder-piston-rod mechanism, the patent employs a piston that moves directly within the cylinder without an external rod, thereby removing the source of hydraulic fluid leakage and extending system reliability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces a cam mechanism as an intermediary between the turnstile rotation and the piston movement. The cam converts the rotational motion into linear piston movement, enabling the piston to reciprocate within the cylinder without requiring a sliding rod that would compromise the sealed hydraulic system

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of substance

If a rotary damper is used instead of cylinder-piston mechanism, then hydraulic fluid loss is prevented, but device complexity and temperature compensation challenges increase

Engineering Contradiction:
Improvehydraulic fluid retentionVSAvoiddamper mechanism complexity
Core Design Contradiction:
Loss of substanceVSDevice complexity

Solution Approach 1:

The invention segments the damping function into two separate cylinder-piston mechanisms operating in sequence. Each piston handles a specific phase of the turnstile rotation, allowing the system to maintain simple sealed cylinders without the complexity of rotary dampers while preventing hydraulic fluid loss through the segmented reciprocating motion

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention employs periodic reciprocating motion of two pistons that alternate in their damping action. As the turnstile rotates, each piston periodically moves back and forth in its cylinder, creating a rhythmic damping effect that simplifies the overall mechanism compared to continuous rotary dampers while maintaining fluid sealing

Inventive Principle:
Principle #19Periodic action

3Speed

If damping force is applied throughout the entire part-rotational movement, then excessive speed is controlled, but the torque-restoring mechanism cannot effectively accelerate the turnstile at the beginning

Engineering Contradiction:
Improveturnstile rotational speed controlVSAvoidtorque-restoring mechanism effectiveness
Core Design Contradiction:
SpeedVSForce

Solution Approach 1:

The invention uses periodic action by having two pistons alternate their damping function throughout the part-rotational movement. The first piston provides damping during the first half of the rotation while the second piston remains inactive, then they switch roles. This periodic engagement allows the torque-restoring mechanism to accelerate the turnstile without excessive damping resistance, while still controlling speed during the damping phases

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The invention applies dynamic control by adjusting the damping force timing to match the operational phases of the turnstile. The pistons are designed to engage damping only during specific portions of the rotation where speed control is needed, while allowing free acceleration during phases where torque-restoring force must dominate, creating a dynamically adaptive damping system

Inventive Principle:
Principle #15Dynamics

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 prevents hydraulic fluid loss and provides efficient, directional-independent damping, allowing for a compact and maintenance-free turnstile operation with consistent performance across temperature variations.

Implementation Method 1

a hydraulic damper for damping the movement of the said turnstile during the second half of said part-rotational movement, which damper comprises a cylinder-piston mechanism which contains a hydraulic fluid

Methodology Applied
Scientific EffectViscous damping: Viscous Damping

Data Source

PatentEP2719855B1Control assembly for controlling the rotation of a turnstile
Publication Date: 2015.07.22 LOCINOX NV
  • EP2719855B1 patent drawingFigure 1
  • EP2719855B1 patent drawingFigure 2
  • EP2719855B1 patent drawingFigure 3

AI summary

The control assembly comprises a torque-restoring mechanism (13) with springs (20), a motion converting transmission with a multiplying gearing (56, 57) converting a rotation of the turnstile over 120° into a rotation of the rotary shaft entering the hydraulic damper (26) over 180°. The hydraulic damper (26) comprises two pistons mounted onto a single piston rod. A cam or crank mechanism converts a rotation of the rotary shaft entering the hydraulic damper over 180° into a reciprocating motion of the two pistons over two half stroke lengths. The first piston damps the rotary movement of the turnstile when moving in one direction whilst the other piston damps this movement when the pistons move in the other direction. The movement of the turnstile is thus damped in both of its rotation directions. The use of such a motion converting transmission in combination with a double-piston mechanism enables to arrange the motion converting mechanism within the hydraulic damper, thus avoiding any loss of hydraulic fluid, and also enables to achieve a gradually increasing damping force to effectively stop the rotation of the turnstile.