Telescopic Pneumatic Ram for Consistent Missile Ejection Force

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing high-speed linear actuators, particularly pneumatic actuators for missile launchers, face challenges in efficiently imparting energy to missiles to reach a safe distance before rocket engine ignition, as the pressure of pressurized gas decreases during the stroke, reducing the force and energy transferred to the missile.

Innovation Solution

A pneumatic actuator with a telescopic ram configuration, where multiple ram members are arranged concentrically, allowing the innermost ram member to be driven by pressurized gas throughout its motion, while other ram members contribute force only when necessary to compensate for diminishing gas pressure, ensuring consistent acceleration and energy transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If pressurized gas is used to drive the missile, then the missile can be ejected to a safe distance, but the gas pressure drops during the stroke reducing the force and energy transferred

Engineering Contradiction:

Improveenergy transferred to missileVSAvoidgas pressure

Core Design Contradiction:

Use of energy by moving objectVSStress or pressure

Solution Approach 1:

The single ram is divided into multiple telescopic ram members (first, second, third members) that can move independently. Each ram member has seals that divide the enclosure into separate chambers, allowing independent pressure management for each segment. This segmentation enables maintaining higher pressure in earlier chambers while later chambers operate at lower pressures, compensating for the natural pressure drop during stroke.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The ram members are designed to dynamically extend and retract in a telescopic arrangement. During the stroke, the ram members extend sequentially as gas pressure drives them, with each member contributing to the total stroke length. This dynamic configuration allows the actuator to maintain effective force over a longer duration despite pressure decay, as each successive ram member is driven by the pressure remaining in its chamber.

Inventive Principle:

Principle #15Dynamics

2Use of energy by moving object

If the stroke length is increased to impart more energy, then more energy can be transferred to the missile, but the actuator height increases beyond acceptable limits

Engineering Contradiction:

Improveenergy imparted to missileVSAvoidactuator height

Core Design Contradiction:

Use of energy by moving objectVSLength of stationary object

Solution Approach 1:

The multiple ram members are arranged in a nested, telescopic configuration where smaller ram members are contained within larger ones during the retracted state. This nesting allows the actuator to achieve a long extended stroke length while maintaining a compact retracted height, as all the ram members collapse into each other within the enclosure, minimizing the overall actuator height when not in use.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Use of energy by moving object

If multiple ram members are used to maintain force throughout the stroke, then energy transfer is improved, but the device complexity increases

Engineering Contradiction:

Improveforce consistency throughout strokeVSAvoidactuator structure

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

Each telescopic ram member serves multiple functions: it acts as a driving element for its specific chamber, provides structural support for subsequent chambers, contributes to the telescopic extension mechanism, and houses seals that prevent gas leakage. This multi-functionality reduces the need for separate components for each function, thereby limiting the increase in overall device complexity despite having multiple ram members.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

This configuration enables the actuator to impart maximum energy to the missile by maintaining force corresponding to the permissible acceleration throughout the stroke, even with limited gas storage volume, thereby achieving a higher reachable height.

Implementation Method 1

pressurized gas is held in a storage vessel and, when required, is led into an enclosure so as to push a ram

Methodology Applied

Scientific EffectGas pressure: Pressure Increase

Implementation Method 2

the force exerted by the gas on the innermost ram member is the only force that contributes to driving the missile

Methodology Applied

Scientific EffectForce: Force

Data Source

PatentUS12066039B2Pneumatic actuator

Publication Date: 2024.08.20 RAFAEL ADVANCED DEFENSE SYST LTD

AI summary

A pneumatic actuator for imparting velocity to a resting object, comprising a fixed member and a ram, the ram having two or more generally elongated ram members,wherein the fixed member is formed with a base plate having an inlet hole therethrough,the ram members are formed and disposed concentrically about the center axis so as to lie one within another and to move in a telescopic arrangement,the innermost one of the ram members is configured to enable it to be driven by any pressurized gas fed through the inlet hole and to drive the object, andeach of the other ram members is configured to move only behind the innermost ram member;the actuator being operative to move the innermost ram member along its entire range of motion and thereby impart velocity to the object.