Safety device for a passenger conveyor

A safety device for a passenger conveyor having a main frame, sprockets at the upper and lower parts of the main frame, endless tread board chains reeved on said sprockets, tread boards connected to said endless tread board chains, endless handrails loosely circulatingly driven along with said tread boards, a driving means for said endless board chains, and handrail driving rollers driven by said driving means and frictionally engaging said handrails in frictional contact for driving said handrails, said safety device comprising:

• a stationary member on said main frame;
• thrust means corresponding to each of said handrails and shiftably held on said stationary member and having the forward end portion directed toward and engaging the inside of the corresponding one of said handrails;
• a tension application means engaged with said thrust means for applying tension to said one of said handrails through said thrust means;
• a detecting means engageable by said thrust means for detecting a shift of said thrust means beyond predetermined limits;
• and
• a pair of guide means on said main frame and extending along the inside of said one of said handrails on opposite sides of said thrust means and being curved concavely outwardly of said stationary member for positively guiding said one of said handrails therealong, and having free ends spaced from each other and the said one handrail being bent freely between said free ends with said forward end portion of said thrust means engaging the bent portion of the one handrail between said free ends, and said free ends being freely movable toward and away from each other with changes in tension in said handrail, whereby said thrust means is positively shifted even for a minor change in the tension of said handrail and any shift of said thrust means beyond the predetermined limits is surely detected.