Latches

About Latches and Latch Manufacturers Including: Catches, Compression Latches, Door Latches, Draw Latches, Slam Latches & Spring Latches.

Latches are a type of mechanical device used to fasten doors, windows, cabinets and other such items that can be either open or closed. Traditionally, latches have been used only to hold doors in the closed position, not to lock them. Bolts, on the other hand, have been used to only lock, while locks are capable of performing both these functions. More recently, however, latches have emerged that are able to both lock and fasten a door or other object. Latches are particularly efficient in situations that call for controlled release and operation. Most latches contain only one bolt, the beveled spring bolt/roller bolt. Latch manufacturers produce latches that are available in a variety of materials: stainless steel latches and plastic latches are just a couple examples. Often, the material of the latches has much to do with its function, such as flexible latches, which are made from rubber and other elastomers, and are used in applications such as vibration isolation.

Many latch manufacturers create latches that vary in design and usage. Draw latches are a general description for any latches that are used to draw together and hold two separate panels. Another, spring latches and slam-action latches, make use of a spring for the actuation motion that pushes or slams a door shut. Rotary latches, rather than a spring, have rotating components within the latch that secure the door. Mortise locks are mounted in a cavity in the door edge, and for this reason are very difficult to force open. One type of latch, a rim latch, is an old-fashioned latch that went out of style in the late 19th century, but is now being revived in period-design houses. These latches are mounted on the inside of a door instead of in the door edge like most modern latches, and because they are less secure, they should not be used as the only means of security for a home. Another type of latch, a safety latch, is used by parents to protect their children from sharp objects and poisons they may find in cabinets and drawers while playing.

Different mounting options are also made available by latch manufacturers. Concealed mounting refers to the situation in which the latches and corresponding mounting hardware are hidden behind the panel, and edge mounting involves installing the latches on the edge of the mating panels. When the latches are mounted directly on the front of the panel, this is called face mounting. Side mounting is when both the latch and the keeper are mounted on the back of the connecting panels and cannot be viewed from the cabinet or door front. Lastly, single-hole mounting involves mounting the latches in a single hole on the panel face. Latching position is also important. Primary latching position means that the door is securely held in a closed position, while secondary latching position refers to a latch that holds the door in a position that is not fully closed.

Latches are useful in virtually any industry, most notably transportation and home- or building-related applications. Transportation uses include latches for the aerospace and automobile industries, as well as for recreational vehicles, railway, marine and off-highway uses. Indoors, latches can be used for nearly anything in the home or workplace that requires a door or cabinet to be held shut, making the industry list numerous. Some important considerations when choosing latches for your application include how many are needed and what they should be made from (whether plastic, stainless steel, brass or rubber). Also important is the surface composition of what the latches are to be mounted on (wall, door, cabinet or window) and what latches are appropriate for such a material. Finally, make sure that the latches mechanism is not too heavy to cause problems when mounted, and that it will stay in position.

Latches and Latch Manufacturers Images Provided by Knuth Hinge Co.

Latches and Latch Manufacturers Images Provided by Sierra Pacific

Types of Latches

• Bored latches are latches with components that are used for installation in bored holes on a door.
  
• Catches are mechanisms used to hold doors closed.
  
• Compression latches are a self-adjusting type of latch.
  
• Cylindrical latches are bored latches that have a cylindrical case into which another latch bolt case may fit.
  
• Door latches are mechanisms that hold doors shut.
  
• Draw latches are designed to draw together and hold two panels.
  
• Flexible latches are made from rubber or another elastomer, and are used in situations when vibration isolation or panel misalignment problems occur.
  
• Floating strike latches are rotary latches that have a vertical clearance pawl.
  
• Flush latches have little or no protrusion from the mounting panel.
  
• Integral latches have a cylinder in the knob.
  
• Mortise latches are not applied to a door’s surface, but rather installed in a mortise.
  
• Narrow case latches are rim latches that are very narrow, generally less than 75mm.
  
• Nightlatches are either mortise or rim latches with a ‘snib’ to hold the latch back if needed. Typically, these latches are not very secure.
  
• Overcenter latches are secured with a member traveling beyond the center.
  
• Paddle latches have flat, flip-out handles used for actuation.
  
• Pin-type latches have a cylindrical pin that is used to strike.
  
• Rim latches are old-fashioned latches that are mounted on the inside of a door instead of inserted into the door edge.
  
• Roller latches use a roller latch head under spring tension to reduce friction. This engages a strike and forms a recess to receive the roller.
  
• Rotary latches have one or more rotating members that are used to secure the door.
  
• Slam latches are activated by the slamming of a door.
  
• Sliding latches use actuation to push or slam the door closed.
  
• Spring latches make use of a spring for the latching operation.
  
• Thumb latches, like rim latches, are another old-fashioned type of latch.
  
• Tube latches have a tubular body, which is inserted into a drilled hole in the door edge.

Latches Terms

Actuation – The movement of the handle or latch portion, which is what causes the latch/unlatch function.

Alike Change – Multiple latches or locks that are able to use the same key.

Anti-Friction Latch Bolt – A latch bolt that is specifically designed to reduce friction.

Architectural Hardware – Hardware used in construction on movable components, such as doors, windows and cabinets.

Axle – A component that provides the bearing surface of the rotating rotor and latch mounting on a rotary latch.

Back Plate – The protective plate on the door onto which the moving parts of the latch are attached.

Bevel – A term that indicates the direction the latch bolt is inclined.

Cam – A tongue on the end of the plug of a latch.

Case – The part of the latch that contains the mechanism.

Catch – The part of the latch that allows for pawl retention.

Clamping Force – The force that is exerted from a latch, in order to draw two panels together.

Coaxial Mount – Allows for maximum strength of rotary latches by combining the standard mount with a second pivot on the bottom of the back plate.

Deadlocking Latch Bolt – A latch bolt with a plunger that is used to prevent the bolt from retraction by end pressure when the door is closed.

Direct Release Actuation – Unlatching by moving the handle or latch directly at the mechanism.

Dogging Device – A device used to fasten the cross bar in the depressed position to keep the latch bolt in the retracted position. This allows for free operation of the door on both sides.

Drop Ring – A ring handle that is attached to a spindle and is used to operate a latch. When not in use, the ring stays in the dropped position.

Four-Point Actuation – Unlocking by moving the handle or latch portion at multiple points.

Front – The area through which the latch bolt projects.

Hinged/Swinging Latch Bolt – A latch bolt that is hinged to the front and retracted by a swinging action.

Hook – A component that allows for a slam action function on a latch.

Latch Bolt – A spring bolt with a beveled edge that may be operated by a handle, knob or turn.

Lip – The projecting piece that the latch bolt strikes when the door is shut.

Mortise – The door cavity that receives the mortise latch.

Plate – The body of the latch, which provides the structural strength.

Plunger – A sliding component of a latch that provides retention for a strike.

Roller Strike – A strike with a rolling member that reduces friction at the point of the latch bolt contact.

Snib – A small switch on a nightlatch, which prevents the latch from being operated when closed.

Springbolt – A bolt that can be pushed back into the lock case and is able to return to the original position without assistance.

Stop – The button that locks or unlocks the latch bolt against the outside knob.

Strike – A metal plate used for protection, which is placed in the doorjamb and receives the latch when the door is closed. This is usually “t”-shaped and has a single hole.

Template Hardware – Hardware that is made exactly to template, precisely matching the spacing of holes and dimensions.

Throw – The maximum projection at which a bolt is fully extended.

Transom Catch – A fastener that is applied to the transom, and has a ring that is used to retract the latch bolt.

Universal – A latch or other piece of hardware that can be used on any door.