Written by Jonathan Coulter, Commercial Product Manager
Compression latches and other touch-point solutions are often overlooked by end consumers, but these products play a vital role in the application as a whole. Compression latches have the power to make a significant impact on the performance, ergonomics, and security of an industrial product or application.
With a wide variety of compression latching solutions available, how does one know what product is ideal for a project? Here are five questions to ask when choosing the appropriate compression latch for an equipment application:
1. What are the specific application requirements?
Compression latches can provide a reliable solution to hold doors and panels shut while, at the same time, eliminating noise, panel movement, or rattling caused by vibration. They can also compress a gasket to provide sealing against environmental elements — such as water, dust, and electromagnetic interference.
To choose the ideal latch for an application, it’s first important to understand how much compression is needed. Different applications may require different amounts of compression, depending on the vibrational forces present or the size of the gasket to be compressed.
Also, heavy-duty applications may require latches with a lever, which provides an increased mechanical advantage, thanks to higher latching forces, and a lower operating effort for users.
For a precise fit and quick installation, a compression latch with a fixed-grip is often an ideal option. A fixed-grip requires no adjustment during installation and typically provides minimal intrusion into the space being sealed.
These components are best suited for applications that:
- Do not need to compensate for a gasket set
- Have tight manufacturing tolerances
- Require no field adjustment because of system wear
In comparison, an adjustable grip can provide a range of grip dimensions, which:
- Compensates for system tolerances
- Can be set specifically based on application variances
- Allows one latch to be used in multiple applications — thereby reducing long-term maintenance and management costs
2. In what environment will the compression latch be used?
This question is important to consider when choosing the material, strength, and overall construction of a latch. First, determine how the latch will be used. For example, a latch may need to be opened and closed several times a day for many years. If so, a supplier is necessary to validate that the latch can accomplish its intended function over a very long lifecycle. Additionally, consider the amount of force the latch must withstand during normal operation or potential unexpected events, which may indicate that it should be made out of durable material, such as zinc or stainless steel.
The physical environment may also present other challenges for a latch. Exterior applications may need to withstand sun and wind exposure, or chemical exposure due to weather or cleaning solvents. Such factors can determine the appropriate material choice to hold up to the elements over time. External factors can also include sealing against moisture, rain, or water spray, which can lead to different latch sealing choices to protect the enclosure interior.
Many customers require compliance with industry-specific standards, such as fire, vibration, and sealing (such as the IP65 rating for dust and water resistance or the NEMA 4 rating for ingress of water), which require latch suppliers to perform testing to validate performance.
3. How will the latch be installed?
Installation requirements are a critical aspect in the search for the ideal compression latch because in many cases, the latch must fit a specific design footprint. For applications with limited mounting space, for example, a smaller compression latch that only requires a single mounting hole may be the best choice. The thickness of the panel where the latch will be mounted also must be considered when selecting the appropriate compression latch.
Another key consideration in selecting a compression latch is the internal space inside the application for the latch placement. If the internal space is at a premium, a latch selection can be made that mounts on the outside of the application and provides minimal intrusion. On the other hand, a flush-mounted or recessed latch may be preferred to reduce the potential risk for clothing or unwanted articles accidentally catching on it.
4. What are the ergonomic and security requirements?
How will the panel that the latch is attached to be opened and closed? How will the latch be operated? Is there a separate handle to aid in opening the enclosure to which it is attached?
These are key questions to consider when choosing the appropriate compression latch. Depending on end-user preference, compression latches can be opened by pushing a button, lifting and turning a handle, turning a knob or rotating a tool. For latches that are accessed by hand with some frequency, a latch that provides an ergonomic solution such as a T-handle or knob may be preferred. These are also beneficial if the user needs to access the application while wearing gloves.
In secure environments, it may necessary to limit access to authorized personnel only. A simple compression latch may meet basic requirements for security, but there are other options that offer advanced security. For example, latches that require specific tools may limit the ability to open the latch. For applications that protect controlled environments, such as storage lockers that house pharmaceuticals, various key locking options are available to further limit access to those individuals who have the correct key, thereby limiting the risk of theft or vandalism.
Latches can also incorporate features to alert a user of previous access (such as visual indication that the compartment has previously been opened), or provide a key retention feature to make sure that the latch is fully engaged before the key can be removed from the lock, increasing confidence that the latch has not been left open. In applications where it’s important to verify that many latches are properly closed from a distance, consider a latch with a visual indication feature.
5. What other factors are important to compression latch selection?
Although environmental requirements and security needs are typically some of the most important factors in selecting a compression latch solution, other factors such as the application’s aesthetic needs may also be important.
As consumer preference increasingly considers aesthetics as a major buying benchmark, consider how the end product will look. Is the latch visible to the end customer? If so, are there high aesthetic standards for this product? Answers to these questions can help clarify the choice of material and finish of the compression latch, with options ranging from polished to chrome-plated.
For instance, in the marine industry, flush-mounted and chrome plated compression latches complement the design aesthetic with a clean, shiny and protrusion-free appearance while at the same time offering durable, lift-and-turn operation. For off-highway industry applications, such as excavators or backhoes, latches that use a common tool for actuation and are painted black may fit better with the more industrial exterior design aesthetic, and be better suited for a construction environment.
When selecting a compression latch, make sure that it’s from an established and respected supplier that has the capability to work directly with an OEM to identify the specific needs of their application. Since these products are extremely specific and often require customization, it’s crucial for the supplier to collaborate effectively to maximize the application’s efficiency, yet minimize its liabilities.
A good supplier will not just meet industry standards for safety and reliability but will strive to exceed them. The longer the supplier has been involved in the production of compression latches, the more likely they are to understand the unique application requirements and be able to provide the best products and customer service. Engineers should seek a supplier that can deliver the product’s promised function and durability, while also providing customer service that exceeds expectations.