Abstract: A headrest stay includes a pair of first stay-composing parts extending in top and bottom directions of a seat back while supported by the seat back, the first stay-composing parts being arranged in different positions in a direction of vehicle width; and a second stay-composing part connecting specific parts of the first stay-composing parts in the direction of the vehicle width, the specific parts extending straight in the top and bottom directions of the seat back. The specific parts face a head of an occupant seated on the seat. A portion of the second stay-composing part, which portion is between the one specific part and the other specific part in the direction of the vehicle width, is not located further forward than the specific parts, and at least part of the portion is located further rearward than the specific parts.

Abstract: An S-spring 14 is provided in a state of tension between a pair of seat back frames 10 constituting a vehicle seat 1. A support section 16a of a bracket 16 fixed to the seat back frame 10 supports a part of an end of the S-spring 14 from behind. The support section 16a is formed with a length equal to or greater than one pitch of the S-spring 14 in a no-load state and discontinuously supports center portions ? of the S-spring 14. When a load equal to or greater than a predetermined level acts on the S-spring 14, the S-spring 14 is stretched to cause the center portions ? to be dislocated from the support sections 16a, and as a result, the length of a deflectable portion of the S-spring 14 is changed.

Abstract: An S-spring 14 is provided in a state of tension between a pair of seat back frames 10 constituting a vehicle seat 1. A support section 16a of a bracket 16 fixed to the seat back frame 10 supports a part of an end of the S-spring 14 from behind. The support section 16a is formed with a length equal to or greater than one pitch of the S-spring 14 in a no-load state and discontinuously supports center portions ? of the S-spring 14. When a load equal to or greater than a predetermined level acts on the S-spring 14, the S-spring 14 is stretched to cause the center portions ? to be dislocated from the support sections 16a, and as a result, the length of a deflectable portion of the S-spring 14 is changed.

Abstract: A headrest stay includes a pair of first stay-composing parts extending in top and bottom directions of a seat back while supported by the seat back, the first stay-composing parts being arranged in different positions in a direction of vehicle width; and a second stay-composing part connecting specific parts of the first stay-composing parts in the direction of the vehicle width, the specific parts extending straight in the top and bottom directions of the seat back. The specific parts face a head of an occupant seated on the seat. A portion of the second stay-composing part, which portion is between the one specific part and the other specific part in the direction of the vehicle width, is not located further forward than the specific parts, and at least part of the portion is located further rearward than the specific parts.

Abstract: An activation control apparatus of an occupant safety system has a floor sensor 32 disposed at a predetermined position in a vehicle and arranged to detect impact on the vehicle and an activation control 40 of the occupant safety system for activating the occupant safety system when an operation value obtained based on a detection value detected by the floor sensor 32 exceeds a predetermined threshold, and the activation control apparatus further has satellite sensors 30A, 30B disposed more to the front than the floor sensor 32 in the vehicle and arranged to detect a level of the impact on the vehicle to detect values of at least two different magnitudes according to the level of the detected impact, and a threshold changer 42 for changing the predetermined threshold in accordance with a detection value of the satellite sensors 30A, 30B.