Marshmellow Brochure

Product catalog summary

Introduction
Marsh Mellow™ springs, developed by Firestone Industrial Products, are innovative fabric and rubber springs designed for vehicular suspension and industrial applications. They are known for their reliability, corrosion resistance, cost-effectiveness, and simplicity. The springs feature a solid rubber core with a hollow center and fabric reinforcement, offering design flexibility and addressing issues associated with solid rubber springs.

Advantages

Constant Vibration Isolation: Maintains a nearly constant natural frequency despite load changes.
High Load Capacity: Capable of greater deflection and load carrying compared to all-rubber parts.
Excellent Vibration Isolation: Low natural frequencies effectively isolate forced frequencies.
Lateral Vibration Isolation: Enhanced isolation in all directions due to lower lateral natural frequency.
Compact Size: Supports greater loads with a smaller footprint.
Corrosion Resistance: Durable in damp and corrosive environments.
Prevents Bottoming-Out: Unlike coil springs, they do not bottom-out under overload.
Reduces Downtime: Rubber construction prevents catastrophic failure.
Increased Stability: Supports lateral stability even at high compression.
Noise Reduction: Minimizes structurally transmitted noise.
Low Cost and Maintenance-Free: High load capability reduces the number of springs needed, with no maintenance required.

Precautions

Temperature: Operating range is -40°F to 135°F; high frequency inputs can increase rubber temperature.
Design Envelope: Ensure adequate clearance to prevent rubbing.
Contaminates: Protect from harmful substances.
Storage: Store in a dark, dry area at room temperature.
Percent Compression: Typically ranges from 15% to 27%.
Allowable Stroke: Delta strain should be less than 7.5%.
Disturbing Frequency Range: Suitable for 800-1200 CPM for medium stroke applications.
Lateral Stability: Decreases as deflection increases; do not exceed load capabilities.
Center of Gravity: Align springs with the center of gravity for stability.
Startup and Shutdown: Resonance can amplify movement; consider dampers to reduce amplitude.
Isolating an Unbalanced Mass: Consider amplitude of movement and add damping if necessary.

Construction
The Marsh Mellow spring's construction includes a solid rubber core, a hollow center, and fabric reinforcement. These elements can be modified to meet specific load and performance requirements. The rubber material affects performance, and the hollow center influences load capacity.

Dynamic Characteristics

Vibration Isolation: The springs isolate vibrations by allowing objects to vibrate without affecting the surrounding environment. The spring rate, which varies with height, is crucial for determining the effectiveness of isolation.
Natural Frequency: A low natural frequency indicates an effective isolator. The natural frequency is calculated based on the spring rate and load.
Transmissibility and Isolation: Transmissibility measures the vibration energy transmitted, while isolation is the energy prevented from transmission.
Resonance and Amplification: Resonance occurs when disturbing and natural frequencies match, leading to increased vibration amplitude. Amplification happens when the disturbing frequency is less than 1.4 times the natural frequency.

Shock Impact and Damping
Marsh Mellow springs are used in shock impact applications to dissipate energy. Damping is achieved through hysteresis, where energy is converted to heat during compression and extension.

Design and Selection
The document outlines a step-by-step process for selecting the appropriate Marsh Mellow spring based on load, deflection, and natural frequency. It emphasizes the importance of considering the load distribution and ensuring the spring operates within its design limits.

Specifications
The document provides detailed specifications for Marsh Mellow springs, including their dimensions, load capacities, and compression characteristics. The springs are designed to operate effectively between 15% and 27.5% compression, with specific measurements provided for different models.

Procedures
The document outlines procedures for selecting and installing Marsh Mellow springs. It includes guidelines for calculating energy dissipation under shock impact conditions and selecting the appropriate spring based on these calculations. The installation process involves fabricating mounting plates, aligning the machine, and ensuring the spring height is within specified limits.

Standards and Recommendations
Recommendations are provided for ensuring lateral stability and vibration isolation. The use of Firestone tension bands is suggested for additional stability in certain applications. The document also advises on checking the temperature of the springs during operation to ensure they are functioning correctly.

Data and Tables
The document includes tables listing various Marsh Mellow spring models with their respective dimensions, load capacities, and frequency ranges. These tables serve as a reference for selecting the appropriate spring based on specific application requirements.

Applications
Marsh Mellow springs are suitable for a variety of applications, including shock absorption in cranes, hammers, and bumpers, as well as vibration isolation in compressors and vibrating screens. The document provides examples of mounting arrangements for different applications.

Marshmellow Brochure

Marshmellow Brochure

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