# US 10,308,214 B2 · Pretensioner, retractor, and seat belt device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,308,214 B2 - Document ID: US10308214B2 - Status: Granted - Kind: B2 - Application number: 15/500,993 - Filed: 2015-07-24 - Published: 2017-08-10 - Granted: 2019-06-04 - Earliest claimed: 2014-08-07 - Assignees: Joyson Safety Systems Japan K.K. - Applicants: Joyson Safety Systems Japan K.K. - Inventors: Tadayuki Asako - Web page: https://patentgrep.com/patent/US10308214B2 ## CPC - B60R 22/46: {Reels} with means to tension the belt in an emergency {by forced winding up}(electrical circuits for triggering safety arrangements B60R21/01 {; tensioners using reels only guiding the belt during normal use, e.g. splitted reels B60R22/195}) - B60R 2022/4642: {the gas directly propelling a flexible driving means, e.g. a plurality of successive masses, in a tubular chamber} - B60R: VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR ## Abstract Provided are a pretensioner, a retractor, and a seat belt device in which strength and slidability of a rod-shaped power transmission member may both be achieved. A pretensioner includes a ring gear on which the spool is rotatably disposed, and power transmission units for transmitting power to the ring gear in an emergency. The power transmission units includes a rod-shaped power transmission member for transmitting power to the ring gear while being plastically deformed, a tip reinforcing member disposed on a tip side of the power transmission member, a pipe for containing the power transmission member, and a gas generator disposed at an end of the pipe. The tip reinforcing member has higher strength than the power transmission member. ## Claims ### Claim 1 A pretensioner comprising: a ring gear to which a spool is rotatably disposed, the spool winding a webbing for restraining an occupant; and power transmission units for transmitting power to the ring gear in an emergency, wherein the power transmission units each comprise a rod-shaped power transmission member for transmitting power to the ring gear while being plastically deformed, a tip reinforcing member disposed on a tip side of the power transmission member, a pipe for containing the power transmission member, and a gas generator disposed at an end of the pipe, the tip reinforcing member has higher strength than the power transmission member, and, the tip reinforcing member is formed such that a length with respect to an axial direction of the power transmission member is smaller than a pitch of the ring gear. ### Claim 2 (depends on 1) The pretensioner according to claim 1, wherein the tip reinforcing member is fixed to the power transmission member, pressed into the pipe, molded in the power transmission member, or made by hardening a part of the power transmission member. ### Claim 3 (depends on 1) The pretensioner according to claim 1, wherein the tip reinforcing member has higher strength than the ring gear. ### Claim 4 A retractor comprising: a spool for winding a webbing that restrains an occupant; and a pretensioner for winding the webbing and eliminating slack in an emergency, wherein the pretensioner comprising a ring gear to which a spool is rotatably disposed; and power transmission units for transmitting power to the ring gear in an emergency, wherein the power transmission units each comprise a rod-shaped power transmission member for transmitting power to the ring gear while being plastically deformed, a tip reinforcing member disposed on a tip side of the power transmission member, a pipe for containing the power transmission member, and a gas generator disposed at an end of the pipe, the tip reinforcing member is formed such that a length with respect to an axial direction of the power transmission member is smaller than a pitch of the ring gear. ### Claim 5 (depends on 4) The retractor according to claim 4, wherein the tip reinforcing member is fixed to the power transmission member, pressing into the pipe, molded in the power transmission member, or made by hardening a part of the power transmission member. ### Claim 6 (depends on 4) The retractor according to claim 4, wherein the tip reinforcing member has higher strength than the ring gear. ### Claim 7 A seat belt device comprising: a webbing for restraining an occupant; a retractor for winding the webbing; a belt anchor for fixing the webbing on a vehicle body side; a buckle disposed on a side surface of the seat; and a tongue disposed in the webbing, wherein the retractor comprising a spool for winding the webbing; and a pretensioner for winding the webbing and eliminating slack in an emergency, wherein the pretensioner comprising a ring gear to which a spool is rotatably disposed; and power transmission units for transmitting power to the ring gear in an emergency, wherein the power transmission units each comprise a rod-shaped power transmission member for transmitting power to the ring gear while being plastically deformed, a tip reinforcing member disposed on a tip side of the power transmission member, a pipe for containing the power transmission member, and a gas generator disposed at an end of the pipe, the tip reinforcing member has higher strength than the power transmission member, and the tip reinforcing member is formed such that a length with respect to an axial direction of the power transmission member is smaller than a pitch of the ring gear. ### Claim 8 (depends on 7) The seat belt device according to claim 7, wherein the tip reinforcing member is fixed to the power transmission member, pressed into the pipe, molded in the power transmission member, or made by hardening a part of the power transmission member. ### Claim 9 (depends on 7) The seat belt device according to claim 7, wherein the tip reinforcing member has higher strength than the ring gear.