Abstract: A coupling lock for an engine and a boat hull installed on the fastening location thereof to provide coupling and locking functions includes a base dock and a upper dock. The base dock is fastened to a transom of the boat to couple with the engine and fasten to the boat. The base dock has two corresponding fastening rods to insert in fastening holes formed on a lock body housed in the upper dock. Locking operation may be accomplished rapidly. The engine coupling section is covered to guard the engine from theft.

Abstract: A coupling lock for an engine and a boat hull installed on the fastening location thereof to provide coupling and locking functions includes a base dock and a upper dock. The base dock is fastened to a transom of the boat to couple with the engine and fasten to the boat. The base dock has two corresponding fastening rods to insert in fastening holes formed on a lock body housed in the upper dock. Locking operation may be accomplished rapidly. The engine coupling section is covered to guard the engine from theft.

Abstract: A trailer lock comprises a rocket bolt, a lock body, and a chain couple. The inner side of the fixed end in the rocket bolt and one of the lock bodies individually has a mounting segment for matching a chain couple with a two-end mounting part and its connection. By the winch design of the chain, it can winch the carrying goods such as bicycle of the supporting base in the end of the car for achieving anti-theft purpose on carrying goods.

Abstract: A tow-deterrent lock for camping trailers includes a latch assembly and a latch bolt dock coupling with each other. The latch bolt dock has a transverse beam on one end that has an inner side bonding to a spherical shell which has a housing chamber with an opening. When a coupling dock extending from a camping trailer is coupled with a towing rod of a vehicle, the housing chamber of the spherical shell may house a fastening nut located below the towing rod to couple with the latch bolt dock and latch assembly to confine and lock the coupling dock and the lower end of the spherical head rod to form a theft-proof protection. When the camping trailer is not coupled with the vehicle, the spherical shell may be wedged into a spherical trough of the coupling dock to couple with the latch bolt dock and latch assembly to lock the coupling dock and form a theft-proof protection. Thus the invention can provide locking and theft-proof function in two use conditions.

Abstract: A guarding lock for a camping trailer and particularly an anti-theft guarding lock for a camping trailer to prevent the trailer from being stolen and hauled away illegitimately mainly includes a lock having a semispherical dome located thereon. A U-shaped lock bar is provided to couple with the lock for fastening to a connection socket of the trailer such that the semispherical dome is housed in and coupled with a semispherical trough formed in the connection socket to achieve anti-theft function for the trailer.

Abstract: An improved lock for a trailer enables a latch bolt to be inserted conveniently, and allows locking and unlocking operations be done easily. The lock mainly consists of a latch bar and a lock member. The lock member includes a latch sleeve, a lock ring, a connection shaft and a lock core. The lock may be easily locked or unlocked by turning a key for 90°.