The Ins and Outs of Toggle Latches: Selecting the Right Latch
Toggle latches provide an elegant solution to the need to ensure equipment accessibility, and when they're locked, offer secure fastening. Using a unique cam action, a toggle latch is stable, strong and dependable, yet the quick release function means it can be opened in a flash.
The wide range of these products means there is one to suit most applications, varying from high-strength units capable of withstanding as much as 7,000 Kg force through to discreet draw latches used on equipment and machinery.
How a Toggle Latch Works
The core principle behind a toggle latch is that of a carefully calibrated cam action that ensures once the latch is closed, it's locked in position. Although a certain force must be exerted to overcome the cam, operation is easy thanks to the leverage provided by the handle, the length of which determines the required force.
Several different terms are used to describe a toggle latch, including overcentre fasteners, draw latch, and quick release fasteners, all of which have the same meaning.
Types of Toggle Latch
The latch range ensures there's a model to suit most applications, and they include:
• Rigid claw: This is a non-adjustable latch with a rigid claw. It's suggested a rubber seal is used to provide some resilience.
• Spring claw: The claw is made from curved spring steel that expands as the latch is closed. An alternative is a claw or mechanism incorporating coil springs.
• Adjustable fastener: The position of the claw can be adjusted using a threaded rod to achieve the required tension.
• Flexible: Incorporates extensible rubber and nylon components that perform the same function as a spring.
• Undercentre latch: A light-duty latch with a reversed handle, sometimes referred to as a draw latch.
• Flush Fitting latch: Used in panels where a smooth finish is required.
• Protex® Prolatch: A special latch that forces a panel or door against a seal.
• Protex® Catchbolt: This latch holds the panel or door firmly in position in three dimensions.
Applications
When selecting a toggle latch, the maximum load to which it will be subject should be determined. Each latch is designed for a maximum load, and it's suggested to use a safe working load that's half its ultimate tensile strength (UTS). The catch plate strength should equal that of the latch. There are four categories of toggle latches:
• Light Duty: Ultimate tensile strength varies between 11 kg and 90 kg.
• Medium Duty: Designed for applications requiring an UTS between 125 kg and 750 kg.
• Heavy Duty: Adjustable latches with a UTS between 1,000 kg and 2,500 kg.
• Super Heavy Duty: With a UTS of 7,000 kg.
Locking and Security Mechanisms
Where required, additional locking features can be specified. These might be to prevent theft, tampering or because the installation is subject to excessive vibration that could cause the latch to open. Additional locking features include:
• Safety catch: The fastener cannot be opened unless the safety catch is released.
• Sealing pin: A spring loaded pin that prevents the catch opening.
• Padlock: For added security; a padlock performs the same function as a sealing pin.
• Keylock: A discreet keylock incorporated inside the latch.
Latch Finishes
Various finishes are offered:
• Zinc plated mild steel: Either a silver or yellow zinc plating.
• Stainless steel: Barrel polished stainless steel, suggested for outdoor use.
• Uncoated mild steel(self finish): Primarily intended for welded attachment and later coating.
• Electrophoretic black: Mild steel coated with electrophoretic paint.
The comprehensive range of Protex toggle latches, overcentre fasteners and quick release draw latches ensures there's a latch suitable for most applications. Contact us to discover how a toggle latch can meet your fastening requirements.
