Disc brake provided with a movement-converting cartridge

A disc brake comprising:

• a floating stirrup (100) straddling a brake disc (2) and supporting a fixed shoe (3);
• a cylinder (110) that houses a brake piston (5) and supports a mobile shoe (4), wherein the fixed shoe (3) and the mobile shoe (4) are positioned to clamp the brake disc;
• the brake piston (5) being controlled by a hydraulic circuit and by a parking brake system via a motion conversion cartridge (200), in that the motion conversion cartridge (200) transforms pivoting motion of a lever (120), borne by the floating stirrup (100), into a translational motion to push the brake piston (5),
• the cylinder (110) having a front part that houses the brake piston (5) and a rear part forming a housing (113) that receives the conversion cartridge (200), the cartridge (200) passing, in a seal-tight manner, through an axial orifice of a bottom (114) of the cylinder to couple a control shaft of the conversion cartridge (200) to the lever (120) of a parking brake,
• characterized in that
• A) the conversion cartridge (200) comprises:
• A1) a rear part (210) pressed against the bottom (114) of the housing (113) of the cylinder and comprising:
• a bearing (211) in the form of a sleeve (212) provided with a flange (213), the bearing (211) being pressed around a through-orifice (115) of the bottom (114) of the housing (113), the sleeve (212) partially passing through the through-orifice (115), and
• a control shaft (220) linked to the lever (120) and bearing a first plate (222),
• A2) a front part (260) pressed against the brake piston (5),
• the front part (260) being permitted to translate relative to the cylinder (110), and the front part (260) being inhibited from rotating relative to the cylinder (110),
• the front part (260) comprising:
• a conversion piston (270) provided with a second plate (272) intended to cooperate with the first plate (222) of the control shaft (220) with an interposition of mobile balls (230) between the first plate (222) and the second plate (272), the mobile balls (230) being positioned on ramps (273) formed in the two plates (222, 272) to transform the relative rotational motion between the two plates (222, 272) into a translational motion of the conversion piston (270), and
• a cage (290) retaining the conversion piston (270) in the cylinder (110) via a clip (201) and a return spring (280) interposed between the cage and the conversion piston acting against the translational motion generated by the plates (222, 272) and the balls (230),
• B) the rear part of the cylinder (110) comprises at least one longitudinal groove (119) and the conversion piston (270) comprises, at its periphery, at least one longitudinal rib (274) having a cross section complementing that of the at least one longitudinal groove (119), to cooperate therewith and block the rotation of the front part (260) of the cartridge (200) while leaving the front part (260) of the cartridge (200) free in translation.