Abstract: It is provided a webbing winding device with good assembly characteristics of components in a second lock unit. In the webbing winding device, due to a leading end of a spring tab of a guide plate interacting with ratchet teeth of an internal ratchet and a second lock base rotating in the pull-out direction in this state, relative rotation occurs between the guide plate and the second lock base, and a second lock pawl is meshed with the ratchet teeth of the internal ratchet. Since this configuration is not a configuration in which relative rotation between the guide plate and a second lock base is induced by bias force of bias means, such as a compression coil spring or the like, there is no bias force received in the rotational circumferential direction when the guide plate and the second lock base are being assembled, resulting in easy assembly.

Abstract: In the present pretensioner, press contact portions are formed further to a side of an open end of a packing housing section than central portions of opposing faces along a depth direction of the packing housing section. Accordingly, when a packing is being fitted into the packing housing section, no great resistance is imparted to a curved face side of the packing from a press contact wall of a housing section body and the opposing face, and the packing is fitted comparatively smoothly therein. Consequently, even when fitting the packing into the packing housing section, a packing main body is largely resilient-deformed, such that a large collapse in a through hole can be prevented, and the sealing ability of the seal due to deformation of the packing main body can be effectively enhanced.

Abstract: In the pretensioner, a guiding wall is provided in a generator-side passing portion of a gas passing portion, and an inner portion of the generator-side passing portion at a portion where the guard wall is set is located to a base end rather than a tip end of a wire protective cylinder. Further, a gas generator mounting hole and the generator-side passing portion is inclined to be directed the base end of the wire protective cylinder. For this reason, gas that is jetted from a gas generator is blown to the base end of the wire protective cylinder or a surrounding portion thereof. As a result, even though the thickness of the wire protective cylinder is not set to be large, it can be against pressure of the blown gas.

Abstract: A pretensioner device in which, at a time of rapid deceleration of a vehicle such as a collision, a gas generator generates gas and the pretensioner device moves a piston in a direction of tensing a webbing. When, due to delayed detection by an acceleration sensor, the gas generator operates after a stretch-out load has been applied to a wire, high-pressure and high-temperature gas within a gas chamber contacts a guard pipe, which is formed of a material having a high thermal conductivity and is disposed within the gas chamber, and is cooled, and passes through a clearance and a pin hole communicating regions to a front and rear of the piston, and is discharged into a cylinder.

Abstract: A pretensioner device in which, at a time of rapid deceleration of a vehicle such as a collision, a gas generator generates gas and the pretensioner device moves a piston in a direction of tensing a webbing. When, due to delayed detection by an acceleration sensor, the gas generator operates after a stretch-out load has been applied to a wire, high-pressure and high-temperature gas within a gas chamber contacts a guard pipe, which is formed of a material having a high thermal conductivity and is disposed within the gas chamber, and is cooled, and passes through a clearance and a pin hole communicating regions to a front and rear of the piston, and is discharged into a cylinder.