Patent ID: 8156774

Claim:
An anti-theft device for a bicycle, the bicycle including handlebars, a saddle, wheels disposed on a front fork ( 7 ) and on a rear stay ( 8 ) by a nut or bolt system and a saddle tube ( 4 ) whose clamping axis comprises a nut or a bolt, the anti-theft device, comprising: a nut ( 9 , 44 ) or bolt ( 21 , 38 ) fitted with at least one ratchet notch ( 16 , 29 , 41 ); a support washer ( 10 , 20 ) defining a peripheral surface that includes a raised portion ( 14 , 32 ); a saddle collar or clamp ( 33 ); at least one mobile guided pin ( 11 , 27 , 36 ), each mobile guided pin being configured to move inside at least one guide passage ( 19 , 31 , 43 ) defined in the support washer ( 10 , 20 ) or the saddle collar or clamp ( 33 ), the at least one mobile guided pin ( 11 , 27 , 36 ) being configured to move to and from first and second positions of use under an effect of gravity and rotation of the anti-theft device, the first position of use being a position in which the bicycle is in a vertical position stood on its wheels, in which at least one mobile guided pin is engaged within the at least one guide passage and permits the tightening/screwing of the nut ( 9 , 44 ) or the bolt ( 21 , 38 ) but prevents loosening/unscrewing thereof, the second position of use being a position in which the bicycle is stood upside down on its handlebars and saddle, and in which the at least one mobile guided pin moves free from the at least one guide passage and permits free rotation of the nut ( 9 , 44 ) or the bolt ( 21 , 38 ) in both directions around its axis, and at least one seal configured to protect the at least one mobile guided pin against environmental factors that could hinder a free movement thereof inside the at least one guide passage.