Spring Latches
Spring latches, commonly located on doors and hinged panels, make use of a tightly coiled spring to fasten two ordinarily separated components. The spring in these latches applies constant pressure to a pin which is fastened to one surface and rests in the notch of an adjacent panel. The ease and simplicity of this latch makes it one of the most common door latches and is found in almost every household, office, commercial and industrial building with latched doors. As they are often used in highly visible and high traffic locations, spring latches are manufactured from a variety of materials including steal, stainless steel, brass and aluminum which can then be coated. Simple spring latches are also used in industrial and utility settings due their ease and durability.
There are two main types of spring latch, the spring bolt latch and the spring loaded latch. The more simplistic version, the spring bolt latch, consists of a bracket attached to one surface and a notched plate in the adjacent surface. The bracket houses a spring attached to a pin which it holds in place. The pin rests in the adjacent notch fastening the two surfaces. The latch is released when the pin is pulled back, recoiling the spring. This type of spring latch is most commonly used in hinged surfaces such as trailers and truck tailgates. The spring loaded latch is more common in home and office doors, but functions in much the same way. Rather than pull directly on the pin, however, these latches have a knob or lever that operates the mechanism and hides much of the hardware within the door. The knob or lever comes in a wide variety of styles which lends to the versatility of this latch in home and office environments. The internal components of the spring latch are stamped from metal and are then spot welded together. The external knobs and levers can be manufactured in many ways, such as casting or forging, depending upon the style.