| 摘要 |
PURPOSE:To prevent the one-sided abrasion of a friction pad by forming the convex part having a high center part onto the piston contact part of the back plate of a friction pad and reducing the shift of the contact position between the piston and the back plate. CONSTITUTION:On the piston side 20 of the both back plates 22 and 22, the convex parts 25 and 25 in spherical surface form are formed so that the top parts form the point contact nearly at the center of the cover body 24 of the piston 20. Therefore, when a caliper 17 is spread by a strong input, the shift of the pressing point of the piston 20 which contacts onto the back plate of a friction pad 21 is little. Therefore, the pushed friction pad 21 always press- attaches with a brake disc by a uniform surface pressure, and brake action is generated, and the one-sided abrasion can be prevented. |
