In any mechanical system, the best components will only deliver optimum performance if they are designed to work together and are properly connected. Nowhere is this better exemplified than in the area of rotary latches.
Rotary latches provide an effective and reliable means of remotely opening interior and exterior doors, compartments, hoods, and other compartments. They combine security with push-to-close convenience.
Typically, a rotary latching system consists of three main elements: the rotary latch itself, the actuator (the interface with user), and the cable which connects these two components. For example, one of the most common everyday uses for a rotary latch is to remotely open the hood of car. In that application, a mechanical lever (the actuator) is activated from the driver’s seat. It connects via a routed cable to the latch in the hood. By pulling the lever, the rotary latch is triggered, allowing the hood to be opened remotely.
What ultimately governs the effective and reliable operation, maintenance requirements, and end-user satisfaction of the latch is the level of compatibility between these three elements. Any compromise will ultimately result in poor performance of the latch. Therefore, with several options available, the design engineer should choose all latch elements from a proven supplier whenever possible.
The Latch
Choosing the appropriate rotary latch is crucial because it acts as the heart of the system. The primary deciding factor in any application should be based on the size or strength of the latch required. For example, it might take a stronger latch to open doors on a large piece of off-highway equipment, whereas a light-duty, compact latch would be well suited for opening hidden storage compartments on a luxury yacht.
Another consideration when choosing the latch is deciding whether the application is best served by a single or two-stage latch. A two-stage latch is recommended if greater assurance the possibility of “false” latching is required, and prevents the possibility of a door accidentally opening or not completely closing. One of the most common example of this are the latches in car doors. Even if a car door isn’t closed all the way, it still latches and won’t open, but it’s still not completely closed and will rattle and vibrate. It takes an extra push to ensure the latch is completely engaged and the door is securely closed.
There are also a variety of latch options available that offer differing performance attributes. The choice will always to some extent be determined by whether the latch is to be used on a rigid or a flexible panel. Beyond that, some latches systems offer multiple triggering options, letting the rotary latch be easily configured and mounted without having to change the overall design of the application.
Another important feature to consider when choosing a rotary latch is whether a single or double rotor is required. Most rotary latches are single rotor, with only one rotor engaging the striker. Double rotor latches however, tolerate misalignments and offer even greater strength than single rotor versions, allowing them to withstand higher working loads. Additionally, rotary solutions can have a built-in bumper that traps the striker between a rubber bumper and the rotor. This eliminates noise and vibration caused by normal operation
