Latch shown in the figure, with success can replace a regular door chain, differing from it reliability and ease of use,— when the door is opened it just enough to push his foot and the path is clear.
The latch consists of three parts: body, tongue and a flat retaining springs. The housing can be made from a piece of aluminum extruded profile suitable cross-section or bending of sheet steel with a thickness of about 3 mm. For the tongue will need a steel plate 15Х30Х80мм. The locking spring is curved from a piece of clock or gramophone.
Latch:
1 — uvula, 2 — body, 3 — screw with nut 4 — retaining spring.
On the tongue are cut two of the locking groove and the sample is the pin for translating the latch to operating position. Axis of the latch is a bolt with thread M5.
Latch cuts flush with the plane of the floor and provorachivaetsya six screws.