Common Types of Latches
Deadbolt latch
– Single-throw bolt engaged in strike plate after door is closed
– Locking mechanism prevents bolt from being retracted by force
– Spring latches
– Knob with crescent-shaped bar pulls back latch bolt
– Latch bolt is spring-loaded with an angled edge
– Engages with strike plate when door is pushed closed
– Bolt automatically extends into strike plate when door is fully closed
– Latch bolt retracts when user turns door handle to open
– Deadlocking latch bolt (deadlatch)
– Elaboration on latch bolt with guardbolt to prevent shimming or jimmying
– Guardbolt held in depressed position by strike plate
Lockset mechanism holds latch bolt in projected position
– Prevents unauthorized entry through credit card or tool
– Draw latch
– Two-part latch with clasp that pulls two parts together
– Used on tool boxes, chests, crates, and windows
– Does not need to be fully closed to secure both halves
– Slam latch
– Activated by slamming or shutting of a door
– Rugged latch ideal for industrial, agricultural, and construction applications

Cam Locks
Cam lock
– Consists of base and cam
– Key or tool used to rotate cam for latching
– Commonly found on garage cabinets, file cabinets, and tool chests
– Electronic cam lock
– Alternative to mechanical cam locks
– Uses electronic key for unlocking
– Key needs to be programmed with user, unlocking date, and time period
– No mechanical keyhole, only three metal contacts
– Electronic key reads ID number of lock for verification

Norfolk and Suffolk Latches
– Norfolk latch
– Thumb-actuated lever used to hold wooden gates and doors closed
– Handle fitted to backplate independently of thumb piece
– Originated in Norfolk, England around 1800-1820
– Suffolk latch
– Thumb-actuated lever used to hold wooden gates and doors closed
– Lack of back plate distinguishes it from Norfolk latch
– Originated in Suffolk, England in the 16th century

Other Types of Latches
– Crossbar
– Primitive fastener consisting of a post barring a door
– Slid past frame or placed into open cleats/hooks to block door
– Used to allow inward opening of doors
– Cabin hook
– Hooked bar that engages into a staple
– Used to hold cupboards, doors, or gates open or shut
– Commonly used on ships and in other domains for door control
– Toggle latch
– Also known as draw latch or draw catch
– Claw or loop catches strike plate in certain position
– Pawl
– Latch that allows movement in one direction but prevents return motion
– Commonly used with ratchet wheel

Applications of Latches
– Architecture
– Latches are typically fitted to doors and windows.
– They provide a secure closure mechanism.
– Latches come in various designs and types.
– They are essential for ensuring privacy and security.
– Latches can be operated manually or electronically.
– Weaponry
– Many types of weaponry incorporate unique latch designs.
– Firearms require specialized latches for loading and firing.
– Break-action firearms have hinged barrels and latches for ammunition access.
– Revolvers use latches to secure the cylinder and frame.
– Knives with folding or retractable blades rely on latches for functionality.
– Automobiles
– Automobiles use latches in doors, hood/bonnet, trunk/boot door, and seat belts.
– Concealed latches secure the hoods of passenger cars.
– Hood pins are used in race cars or aftermarket hoods.
– Seatbelt latches fasten the belts to restrain occupants.
– Parking pawls latch the transmission in park mode.
– Bakeware
– Spring latches are used in springform pans to hold the walls in place.
– They provide easy release of baked goods without damaging them.
– Spring latches ensure a tight seal for baking purposes.
– These latches are commonly used in cake and tart pans.
– They allow for easy removal of the baked goods from the pan.
– Other
– Crossbows incorporate latches to hold the drawn bowstring.
Door chains and electric strikes are related latch mechanisms.
Single-point locking systems use latches for security.
– Snibs are latch-like devices used for fastening doors.
– Latch mechanisms can be found in various industries and applications.Sources: