Limit Switch for Scissor Lift Parts in Dingli Sinoboom and LGMG Brands

Brand New Limit Switch for Dingli Sinoboom LGMG Scissor Lifts

Product Overview: Limit Switch for Scissor Lifts

A Limit Switch is a critical electromechanical safety device used to automatically monitor and control the movement of scissor lifts. Its primary function is to prevent the lift from operating outside its designed safe parameters, thereby protecting the machine, the operator, and the surrounding environment.

Primary Function:
To interrupt the electrical circuit controlling a specific motion (like elevation or extension) when a predetermined limit is reached. It acts as a vital fail-safe to enforce the mechanical boundaries of the equipment.

Key Features & Technical Specifications:

• Actuation Type: Typically a roller lever arm or push plunger design, which is physically triggered by contact with a cam or striker plate on the moving scissor mechanism.

• Enclosure Rating: High-quality switches feature a robust, dust-tight and water-resistant enclosure (e.g., IP65, IP67) to withstand harsh job site conditions, including exposure to dust, moisture, and debris.

• Electrical Configuration: Generally Single-Pole, Double-Throw (SPDT) configuration, also known as a "changeover" switch. This provides both a Normally Open (NO) and a Normally Closed (NC) circuit, offering flexibility for different control logic requirements.

• Durability: Constructed from durable materials like polycarbonate or metal for the housing and lever arm to resist impact and wear over thousands of cycles.

• Safety Compliance: Designed to meet relevant machinery safety standards, ensuring reliable performance as part of the lift's overall safety system.

Common Applications on Scissor Lifts:

Limit switches are strategically placed to enforce several key operational limits:

1. Upper Travel Limit (Primary): The most critical safety function. This switch stops the upward movement of the platform just before it reaches its maximum safe height, preventing over-extension and potential structural failure.

2. Lower Travel Limit: Prevents the scissor arms from over-compacting or the platform from lowering onto the chassis, which could damage hydraulic cylinders or mechanical components.

3. Tilt/Level Sensor Interlock: Often integrated with the machine's tilt alarm system. If the lift tilts beyond a safe angle, the limit switch can prevent further elevation or driving.

4. Platform Gate/Latch Sensor: Ensures the platform entry gate is fully closed and latched before allowing the lift to elevate or move.

Compatibility & Brand-Specific Considerations:

This product category includes direct replacement switches for leading Chinese manufacturers:

• Dingli (鼎力): A leading global manufacturer of aerial work platforms. Their scissor lifts use limit switches that are critical for complying with international safety certifications.

• Sinoboom (星邦): Another major player, known for a wide range of lifts. Their switches are engineered for the specific mechanical and electrical requirements of their models.

• LGMG (临工重机): A prominent manufacturer whose equipment requires reliable, durable limit switches to ensure safe operation on construction and industrial sites.

Important Note: While the fundamental principle is the same, the physical mounting, actuator arm length, and electrical connector are often brand and model-specific. Using the correct OEM or high-quality cross-compatible part is essential for proper fit and, most importantly, safety.

Purpose & Importance:

• Operator & Asset Safety: Prevents catastrophic failures like the collapse of the scissor mechanism.

• Machine Protection: Safeguards expensive components like hydraulic systems, motors, and structures from damage caused by over-travel.

• Regulatory Compliance: Essential for the lift to meet ANSI, CE, and other international safety standards.

• Reliability: A faulty limit switch is a common cause of lift downtime. A high-quality replacement ensures operational reliability.

Common Reasons for Replacement:

• Mechanical Failure: The roller lever arm breaks, or the plunger jams due to wear or impact.

• Electrical Failure: Internal contacts wear out or burn out, preventing the switch from opening or closing the circuit.

• Physical Damage: The housing can be cracked or damaged by accidental impact or improper handling.

• Environmental Degradation: Over time, seals can degrade, allowing moisture or contaminants to enter and cause corrosion or short circuits.