Faced with so many hardware accessories for door (different plunger latch structure, ergonomic fitness and aesthetic perspective), it seems easy for design engineers to find the most appropriate latches. However, there are too many kinds to choose, so the design engineers can easily make the wrong choice. Remember that, let's introduce several parameter features to consider when selecting door hardware and some specific style of latches, so as to make it convenient for designers to make the best choice faster and more easily in acceptable product solutions.
No matter which kinds of style of latches, any kind of application will have one or more size parameters need to consider for designers when making the choice. One of that is clamping size (clamping size is the distance between the surface of door plank and latches and door frames or among the armature connection points). Some latches design is not strict with clamping size, including those that allowed a certain extent adjustment in the final installation phase. And some design requires careful consideration, especially in the high vibration environment demanding environment seal or no noise. Other important items to consider: for any kinds of latches, the distance from the middle line of latches to door frame or among the armatures, the out and rotation space of the latch structure behind the door, and the handle clearance and surface area when users use it.
Doctor-bar Plunger Latch
This kind of lock latch is often the simplest and the most economical one, especially it is easy to use in a single span installation. Doctor-bar plunger latch is very suitable for basic application places, for there is no strict performance or size requirements. However, even in the most simple application, some aspects also need considering, which can eventually lead to a different choice. Whether because of tolerant errors of construction or possibly change in application places, we have to consider installation of long-term fitness. Doctor-bar plunger latch qualified with fixed clamping size is different from adjustable one allowing users adjust it himself to reduce the amount of latch to select. Designers can also put the door and its frame tightly together by slightly bent (or "tilt") the plunger of the latch or pull the door open by spring. In order to control or restrict access from the doorway, designers can choose in a variety of tools or key lock
Pressure Plunger Latch
When tightly closed is essential (in a high vibration environment to reduce sounds and noise or for dustproof, moisture or EMI/RFI shielding pad assembly application and ensure satisfactory sealing degrees), pressure lock latch is obviously the designer's satisfaction choice. But even within the scope of the pressure lock latches; there are still a large number of choices suitable for different needs. Many types of pressure lock latch can provide safe and reliable connection with built-in "tension" device, which can make latches handle in the closed position even in vibration. The place that needs continuous force, perhaps because the cause of the liner pressure balance, the designer should choose the lock with a preset tension bars. For less important devices, automatically adjusted pressure lock latch can maximum reduce the demands for listing excessive latches style and model. A lot of pressure lock latches can also provide the convenient performance to put the handle and the latch together to meet the ergonomic switch requirements, so that the operator can release the pressure of the door and opened the door with a coherent action.
Pushing Plunger Latch
Pushing plunger latch (also called percussive latch), as one of the most convenient and practical latch style, is one of the most popular choice. Of course, easy to use (simply push the door can be closed) is an ideal feature of user friendly design for the end user. However, there are several aspects to consider, which may soon disappoint users if ignored. One of the important factors is this kind of lock latch may be especially sensitive to the application of the clamping size, which can limit according to the narrow size range. Choose inappropriate latches, or in the application where clamping size will change over time, there will be some trouble. If the clamping size is not big enough for latches, the loose-installed door will rattled. On the contrary, if the clamping size is too big, it could lead to inappropriate latch connection, so the close or butt is more arduous; the worst case is that can cause the door open accidentally or cannot be closed or fixed.
Pulling Plunger Latch
A unique characteristic of pulling plunger latch is that it is designed for applying to places for pulling two coplanar door plant by closing power. Lever and whirling chip design can provide the mechanical advantage of producing pull action. Turn the handle bars also has the advantages of quick release, and plane installation settings can reduce the need of extruding toward the inside of enclosed area. Bending metal claw or ring design can provide elastic resilience under shock state, and the across-midline-movement of the latch can make its handle remain shut down even in vibration. Many pulling plunger latch have basically practical design, and at the same time, there are more beautiful and modern design for those marked application. They will be used in handles made of metal, plastic, synthetic rubber or rubber, being used in indoor, outdoor, and environment of possible corrosion. Specially designed model can also appear in butt joint or right angle application.
Multipoint Plunger Latch
Multi-point lock is basically the extension of other latches style (such as doctor-bar plunger, pressure or pushing type), and this kind joint with doors of enclosed area on multiple point, which has more benefits for some applications. For relatively long span door (especially to the door with high bending degree), lock latch can provide you with the effect of stability, security, and quiet for your installation. Perhaps the most common multipoint latches system application is a three point joint one, and the joint points are respectively in the middle of the door, the top and bottom. It fixed the three side along without the door hinge in the system, which can reduce the possible noise, minimize the peer points destroyers could use and guarantee the door can close very well all around (which is a key consideration in liner door application). Two bolt (top and bottom) also can appear in the places where the central part of the door cannot have lock latch points. Multi-point lock with four or more adjustable junction points will also appear in extended door or places where continuous sealing is particularly important.
In any applications, of course, we should always consider rated load, size compatibility and corrosion resistance or decorative painting, etc. Some of the decision point may be flexible, while some will be limited by the installation environment. For example, in the applicable places where shock and vibration are common, the lock latch with the performance of the midline can help prevent latches from suddenly loose at the time of particularly big pressure.
Latches style, size, material, or different paint may increase the possibility to meet the designers' requirement to make the ideal choice for hardware. Therefore, consulting with an experienced supplier of door hardware to get some new ideas related to the application requirements can often be better than automatically satisfied for the selection of lock latch in the past.
Finally to emphasize is that don't stop the evaluation of latches and other door hardware, unless the design cycle has ended. Otherwise, the selection of ergonomic or aesthetic aspects may be severely limited, which will make the confinement cannot operate with the best efficiency of the design, or the worst, may be forced to redesign the products in order to make the necessary latches function normally. Even in the simplest closed places may also appear problems, it will be more expensive in the application of some enclosed areas or other places with high rigorous requirement and limited space.