Hasp tongs in advance

Hasp tongs in advance includes: the main frame, in advance the hasp unit, press from both sides tight unit, positioning unit and detecting element, hasp unit and main frame attach press from both sides tight unit and are connected with the last lower extreme of main frame in advance, positioning unit is connected with the main frame left end, detecting element is connected with the main frame right -hand member. Wherein, the hasp unit includes in advance: flexible jar, first connecting piece, second connecting piece, the one or eight angled pipe, first connecting block, second connecting blockand the third connecting block struck out. The utility model discloses compare with the conventional art, adopt the hasp tongs in advance device, hasp tongs in advance passes through the positioningunit location, signals gave controlling means after detecting element detected the part, the controlling means give -out order, it presss from both sides tightly to press from both sides tight unit, guarantee can not take plac