Latchbolt slide extension

Claim 1

In a slide extension for a cylindrical lockset having: a spring-loaded latch comprising a latch front, a latch case passing through the latch front and being secured thereto, one end of the latch case being formed with hook plates, a sliding member being furnished at one end with a latch bolt and at the other end with a latch bar, the sliding member being slidably disposed in the latch case; a cylindrical body comprising a cylindrical housing which is provided at both sides with a pair of rotatable spindles, the cylindrical housing being formed at the periphery with a U-shaped retractor, a pair of knobs being respectively secured to the spindles, a pivotal shaft provided with a retractor being disposed in the interior of the cylindrical housing such that the pivotal shaft can be driven to move the sliding member of the spring-loaded latch in a predetermined manner by means of rotating the knobs thereof; the improvement comprising a slide extension comprising a latch front which is formed at one end with a U-shaped member perpendicular thereto and at the other end with a pair of parallel U-shaped members which extend along the same direction as the U-shaped member whereby the U-shaped member thereof is engaged with the latch bar of the sliding member of the spring-loaded latch and said two parallel U-shaped members thereof are engaged with the retractor of the pivotal shaft of the lock body.