# US 7,607,604 B2 · Seat belt tensioner > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,607,604 B2 - Document ID: US7607604B2 - Status: Granted - Kind: B2 - Application number: 11/279,456 - Filed: 2006-04-12 - Published: 2006-10-26 - Granted: 2009-10-27 - Earliest claimed: 2004-03-09 - Assignees: Takata Corporation - Inventors: Walter Scherzinger; Roland Schnabl; Thomas Schwer - Web page: https://patentgrep.com/patent/US7607604B2 ## 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 22/4676: {comprising energy-absorbing means operating between belt reel and retractor frame} - B60R 2022/284: {using electric or magnetic braking means} - B60R 2022/288: {with means to adjust or regulate the amount of energy to be absorbed} - B60R 2022/4666: {characterised by electric actuators} - B60R 2022/468: {characterised by clutching means between actuator and belt reel} - B60R 2022/4685: {with means to adjust or regulate the tensioning force in relation to external parameters} - B60R: VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR ## Abstract The disclosed seat belt tensioner may comprise a drive motor, a gear connected to the drive motor, and a seat belt spindle connected to the gear by a spindle clutch. The spindle clutch may have spindle clutch pawls, which engage in pawl teeth of the seat belt spindle to couple the seat belt spindle and the gear. The spindle clutch may also comprise a synchronization pawl configured to alit the pawl teeth before the spindle clutch pawls engage in the pawl teeth. ## Claims ### Claim 1 A seat belt tensioner comprising: a drive motor; a gear connected to the drive motor; a seat belt spindle connected to the gear by a spindle clutch, wherein the seat belt spindle comprises pawl teeth, wherein the spindle clutch comprises spindle clutch pawls for engaging in the pawl teeth to couple the seat belt spindle and the gear; and a synchronization pawl configured to align the pawl teeth by engaging with the pawl teeth before the spindle clutch pawls pivot in toward the direction of the pawl teeth and engage in the pawl teeth. ### Claim 2 (depends on 1) The seat belt tensioner according to claim 1, wherein the synchronization pawl aligns the pawl teeth by being configured to engage completely in the pawl teeth before the spindle clutch pawls of the spindle clutch engage in the pawl teeth. ### Claim 3 (depends on 1) The seat belt tensioner according to claim 1, wherein the spindle clutch is configured to engage when the drive motor rotates in a seat belt-tensioning direction of rotation and disengages when the drive motor rotates in a seat belt-unrolling direction of rotation. ### Claim 4 (depends on 1) The seat belt tensioner according to claim 1, wherein the pawl teeth are arranged on the seat belt spindle, wherein the spindle clutch pawls are configured to be inserted into the pawl teeth of the seat belt spindle as soon as a spindle clutch toothed ring of the spindle clutch rotates in a seat belt-tensioning direction of rotation such that the seat belt spindle and the spindle clutch toothed ring are coupled to each other in a rotationally fixed manner, and wherein the spindle clutch pawls are configured to be pivoted out of the pawl teeth of the seat belt spindle when the spindle clutch toothed ring rotates in a seat belt-unrolling direction such that the seat belt spindle and the spindle clutch toothed ring are separated. ### Claim 5 (depends on 1) The seat belt tensioner according to claim 1, wherein the gear is a mechanical automatic gear that shifts automatically as a function of load. ### Claim 6 (depends on 5) The seat belt tensioner according to claim 5, wherein the automatic gear has a first force transmission path for a first speed with a first transmission ratio and at least one further force transmission path for a second speed with a second transmission ratio that is larger than the first transmission ratio. ### Claim 7 (depends on 6) The seat belt tensioner according to claim 6, wherein the first force transmission path comprises a sliding clutch that disengages when a predetermined switching-off moment is exceeded such that the further force transmission path is activated. ### Claim 8 (depends on 7) The seat belt tensioner according to claim 7, wherein the automatic gear has a planetary gear, wherein the planetary gear is arranged in the further force transmission path, and wherein the planetary gear is configured to revolve in a manner free from force transmission when the sliding clutch is engaged and, when the sliding clutch is disengaged, is used for the force transmission and provides the second speed of the automatic gear. ### Claim 9 (depends on 6) The seat belt tensioner according to claim 6, wherein the first force transmission path has a sliding clutch, a coupling wheel connected to the sliding clutch, and a spindle clutch toothed ring connected to the seat belt spindle and the coupling wheel. ### Claim 10 (depends on 5) The seat belt tensioner according to claim 5, wherein the automatic gear has a planetary gear. ### Claim 11 (depends on 10) The seat belt tensioner according to claim 10, wherein the automatic gear has a force transmission path for a first speed with a first transmission ratio and at least one further force transmission path for a second speed with a second transmission ratio that is larger than the first transmission ratio, wherein the planetary gear is arranged in the further force transmission path. ### Claim 12 (depends on 10) The seat belt tensioner according to claim 10, wherein the planetary gear has a crown wheel connected to at least one planet wheel driven by an internal sun wheel, and wherein the planetary gear has an external sun wheel driven by a connecting gearwheel and connected in a rotationally fixed manner to the internal sun wheel. ### Claim 13 (depends on 5) The seat belt tensioner according to claim 5, wherein an overload clutch is arranged between the automatic gear and the seat belt spindle and is configured to transmit torques up to a predetermined maximum torque and, when the maximum torque is exceeded, disengages. ### Claim 14 (depends on 13) The seat belt tensioner according to claim 13, wherein the overload clutch has first and second coupling elements configured to form a force-locked connection between the automatic gear and the seat belt spindle in an engaging state of the overload clutch and to have a slip in a disengaging state of the overload clutch. ### Claim 15 (depends on 1) The seat belt tensioner according to claim 1, wherein the seat belt tensioner has a blocking device configured to block the seat belt spindle in a tensioned position after an end of a tensioning operation. ### Claim 16 (depends on 15) The seat belt tensioner according to claim 15, wherein the blocking device is configured such that the blocking device can be released without increasing a seat belt restraining force acting on a vehicle occupant. ### Claim 17 A seat belt tensioner comprising: a gear; a seat belt spindle connected to the gear by a spindle clutch, wherein the seat belt spindle comprises pawl teeth, wherein the spindle clutch comprises spindle clutch pawls for engaging in the pawl teeth to couple the seat belt spindle and the gear; a synchronization pawl configured to align the pawl teeth by engaging with the pawl teeth before the spindle clutch pawls pivot in toward the direction of the pawl teeth and engage in the pawl teeth; and a blocking device configured to block the seat belt spindle in a tensioned position after an end of a tensioning operation, wherein the blocking device has a latching pawl configured to be brought into a first pawl position for blocking the seat belt spindle in a seat belt-unrolling direction and into a second pawl position for blocking the seat belt spindle in a seat belt-tensioning direction. ### Claim 18 (depends on 17) The seat-belt tensioner according to claim 17, wherein the latching pawl is configured in such a manner that, when there is a predetermined seat-belt-extraction force that bears against a shoulder of a vehicle occupant, said latching pawl is pivoted from the first pawl position into the second pawl position. ### Claim 19 (depends on 17) The seat-belt tensioner according to claim 17, wherein a pivot pin of the latching pawl is arranged in an elongated hole of the latching pawl in such a manner that the latching pawl can be pivoted in a direction of rotation about the pivot pin and can be deflected radially to the pivot pin along a guide slot formed by the elongated hole. ### Claim 20 (depends on 17) The seat belt tensioner according to claim 17, wherein the synchronization pawl aligns the pawl teeth by being configured to engage completely in the pawl teeth before the spindle clutch pawls of the spindle clutch engage in the pawl teeth. ### Claim 21 A seat belt tensioner comprising: a mechanical automatic gear having first and second force transmission paths; a seat belt spindle connected to the gear by a spindle clutch, wherein the seat belt spindle comprises pawl teeth, wherein the spindle clutch comprises spindle clutch pawls for engaging in the pawl teeth to couple the seat belt spindle and the gear; and a synchronization pawl configured to align the pawl teeth by engaging with the pawl teeth before the spindle clutch pawls pivot in toward the direction of the pawl teeth and engage in the pawl teeth, wherein the first force transmission path comprises a sliding clutch that disengages when a predetermined switching-off moment is exceeded such that the second force transmission path is activated, and wherein a first sliding clutch pawl is mounted pivotably on a pawl carrier such that the first sliding clutch pawl is configured to be pivoted into a coupling position and into a disengaging position. ### Claim 22 (depends on 21) The seat belt tensioner according to claim 21, wherein the synchronization pawl aligns the pawl teeth by being configured to engage completely in the pawl teeth before the spindle clutch pawls of the spindle clutch engage in the pawl teeth.