Safety belt system with a pretensioner and a locking mechanism and method for tightening a safety belt

Abstract

A system (210) for providing occupant restraint, the system (210) comprising: a safety belt (260; 301; 501) having one end; a load-limiting tensioning mechanism (220) configured to remove slack from the end of the seat belt (260; 301; 501) in response to an event; and a locking mechanism (230) configured to lock the end of the seat belt (260; 301; 501) after the tensioning mechanism (220) removes the slack, wherein the tensioning mechanism (220) comprises: a piston (523) and a cylinder (523), wherein the piston (523) is configured to move along the cylinder (523); a cable (340; 521; 621) comprising a first end and a second end, the cable (340; 521; 621) being connected at the first end to the seat belt (260; 301; 501) and being connected at the second end to the piston (523); an ignition charge (515) configured to cause the piston (523) to move along the cylinder (523) to apply tension to the seat belt (260; 301; 501); and a limit switch (524) disposed at a position along the cylinder (523) and configured to provide a signal when the piston (523) reaches the position along the cylinder (523).

Description

INTRODUCTIONThe present disclosure is directed to a seatbelt system having a tensioning mechanism and a locking mechanism.SUMMARYVehicle occupant restraint systems may include a belt having a shoulder region and a pelvis region. DE 695 18 562 T2 relates to a seat belt pretensioner device for tightening a seat belt upon sudden deceleration of a vehicle, wherein a retractor moves due to the action of an inertial force to prevent a carrier from shifting in a direction of withdrawal. DE 10 2016 123 307 A1 relates to a force limiting device for a seat belt system in a vehicle, which has a force wall element that interacts with a belt strap in order to specify a pull-out force that is necessary to move the belt strap with respect to the force wall element.The shoulder and pelvis regions may be under biasing forces determined by a biasing performance, a seat height and a backrest stiffness, a looseness of an occupant's clothing, a pre-tensioning of the belt by an occupant during the buckling, a loosening by an occupant, or a combination thereof. In some circumstances, the above parameters may result in a combination that results in slack in the belt, which may reduce the efficiency of the restraint system. It would be advantageous if the restraint system eliminated slack by a tension member before restraining the occupant.The present disclosure is based on the object of eliminating the slack of a seat belt of an occupant restraint system.The object is achieved by systems for providing occupant restraint according to claims 1 and 8 and by a method for tightening a seat belt according to claim 14.Various embodiments are defined by the dependent claims.BRIEF DESCRIPTION OF THE DRAWINGSThe present disclosure will be described in detail according to one or more different embodiments with reference to the following figures. The drawings are for illustrative purposes only and are merely representative or exemplary embodiments. It should be noted that these drawings are not necessarily to scale for clarity and for ease of illustration. FIG. 1 shows a front view and a side view of exemplary vehicle seats with restraint systems in accordance with some embodiments of the present disclosure; FIG. 2 shows a block diagram of an example system for tensioning and locking passenger restraint of a vehicle, in accordance with some embodiments of the present disclosure; FIGS. 3-4 show an example tensioning mechanism and an example locking mechanism in two states according to some embodiments of the present disclosure; FIG. 5 illustrates an example tensioning mechanism and an example locking mechanism using squibs in accordance with some embodiments of the present disclosure; FIG. 6 shows an upper cross-sectional view of an exemplary latch mechanism in two states according to some embodiments of the present disclosure; FIG. 7 shows front views of multiple example vehicle seats with restraint systems in accordance with some embodiments of the present disclosure; and FIG. 8 shows a flow diagram of an example method of tightening and locking, in accordance with some embodiments of the present disclosure.DETAILED DESCRIPTIONThe present disclosure relates to vehicle occupant restraint systems that apply and lock tension in response to an event. In some embodiments, the system includes a force limiting mechanism. The force limiting mechanism ensures that during a pre-tensioning phase, a certain force threshold value is never exceeded for both the shoulder and the pelvis region of the belt. In some embodiments, force limitation is achieved for the shoulder portion using a retractor biased by a torque rod and for the pelvis portion using a biasing device (e.g., a tensioning mechanism).In the event of a collision, impulse, or other sensed event for which an occupant may be accelerated relative to the seat and vehicle (also referred to herein as an "event"), the restraint system applies tension to eliminate slack in a belt area before locking the length of the belt. This method allows the strap to be secured prior to locking, thereby reducing the movement of the occupant away from the seat during an event.FIG. 1 shows a front view and a side view of exemplary vehicle seats with restraint systems in accordance with some embodiments of the present disclosure.The panel 100 shows a side view of a system including a seat and a restraint system. The seat includes an upper portion 101 and a lower portion 102. The restraint system includes a seatbelt (also referred to herein as a "strap") having an upper portion 111 and a lower portion 112 anchored to the upper tension member 113 and the lower tension member 114. In some embodiments, the strap passes through a connector 115 which may include a passage (e.g., a D-loop or other ring) and a buckle mechanism. For example, the upper portion 111 and the lower portion 112 may be portions of a single strap that passes through a loop of the connector 115. In some embodiments, the upper portion 111 and the lower portion 112 are separate straps that are each connected to the connector 115.In an illustrative example, an occupant may sit on the lower portion 102 and lean against the upper portion 101. After deployment, the occupant may attach the connector 115 to a corresponding receptacle (e.g., the receptacle 166 of the panel 150) to attach the restraint system. The upper clamping element 113 can exert a first force on the upper region 111, which can be partially transmitted or not at all transmitted to the lower region 112. The lower clamping element 114 can exert a second force on the lower region 112, which can be partially transmitted to the upper region 111 or cannot be transmitted at all. Accordingly, the connector 115 can reduce or prevent tension in one region of the strap from affecting the other region, thereby causing some slack to form in one of the regions.Panel 150 shows a front view of a system including a seat and a restraint system. The seat includes an upper portion 151 and a lower portion 152. The restraint system includes a strap having an upper portion 161 anchored to the upper tension member 163 and a lower portion 162 anchored to the lower tension member 164. In some embodiments, the strap passes through the connector 165, which may include a passage (e.g., a D-loop, a ring, or a slot) and a buckle mechanism (e.g., for engaging the receiver 166 attached to the lower portion 152 or the vehicle floor). For example, the upper portion 161 and the lower portion 162 may be portions of a single strap that passes through a loop of the connector 165. In some embodiments, the upper portion 161 and the lower portion 162 are separate straps, each connected to the connector 165.In an illustrative example, an occupant may sit on the lower portion 152 and lean against the upper portion 151. After deployment, the occupant may attach the connector 165 to the receptacle 166 to secure the restraint system. The upper tension member 163 may exert a first force on the upper portion 161, which in some embodiments may be partially transferred to the lower portion 162, but need not be transferred. The lower tension member 164 may apply a second force to the lower portion 162, which in some embodiments may be partially transferred to the upper portion 161, but need not be transferred. Accordingly, the connector 165 may reduce or prevent tension in one region of the strap from affecting the other region, thereby causing some slack to form in one of the regions.In an illustrative example, a vehicle may be equipped with a pre-sensing system configured to trigger either or both of the upper tension member 163 and the lower tension member 164, which may be motor driven. Prior to impact, either or both of the tension members exert a force on the seatbelt to eliminate most of the slack from the seatbelt system (e.g., lower portion 162, upper portion 161, or both). In some embodiments, the tensioning mechanism (e.g., upper tension member 163 and / or lower tension member 164 for shoulder and / or pelvic regions) engages (e.g., pyro-based pretensioner actuators) to further reduce slack in the already biased strap. The systems of the present disclosure include force restrictors (e.g., in either or both of the upper tension member 163 and the lower tension member 164) to prevent over-tension that could result in strong forces on the occupant. For example, either or both of the upper tension member 163 and the lower tension member 164 may include a force limiting mechanism (e.g., an energy absorbing member such as a spring, wire, or other member to reduce or otherwise limit the force) that helps ensure that a certain force threshold is not exceeded for both the shoulder and lap belts during the pre-tensioning phase. To illustrate, either or both of the upper tension member 163 and the lower tension member 164 may include a retractor that biases through the torque rod (e.g., a coil on which the seatbelt is wound).FIG. 2 shows a block diagram of an example system 210 for tensioning and locking passenger restraint of a vehicle 200 in accordance with some embodiments of the present disclosure. The vehicle 200 includes, as illustrated, a seatbelt 260, a system 210, a tensioning mechanism 220, a locking mechanism 230, any suitable mechanisms associated with the tensioning mechanism 220 and the locking mechanism 230, and one or more sensors 240. The tensioning mechanism 220 applies tension to a portion of the seatbelt 260 in response to an event. Applying voltage may include applying a force to retract the region (e.g., so as to shorten it). The locking mechanism 230 prevents extension of the portion of the seatbelt 260 by locking the length of the portion. As illustrated, the system 210 is a restraint control system that includes one or more sensors 240, a control circuitry 211, a memory 212, a sensor interface 213, a power supply interface 214, a signal generator 215, and an input interface 216. In some embodiments, the vehicle 200 includes a component of a restraint system, such as a module disposed at a terminal end of a seatbelt (e.g., the lower tension member 164 of FIG. 1 ).As illustrated, the system 210 includes a control circuitry 211 (which may include, e.g., one or more processors), a memory 212, a sensor interface 213, a power supply interface 214, a signal generator 215, and an input interface 216. The control circuitry 211 may include hardware, software, or both implemented on one or more modules configured to provide control, monitoring, or both of the tensioning mechanism 220, the locking mechanism 230, or both. In some embodiments, control circuitry 211 includes one or more microprocessors, microcontrollers, digital signal processors, programmable logic devices, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), or any suitable combination thereof. In some embodiments, control circuitry 211 is distributed among more than one processor or processing units. In some embodiments, the control circuitry 211 executes instructions stored in the memory 212 to manage one or more of the tensioning mechanism 220, the locking mechanism 230, and one or more sensors 240. In some embodiments, the memory 212 is an electronic storage device that is part of the control circuitry 211. For example, the memory 212 may be configured to store electronic data, computer instructions, applications, firmware, or any other suitable information. In some embodiments, the memory 212 includes random access memory, read-only memory, hard disk drives, optical drives, solid state devices, or other suitable storage devices, or a combination thereof. For example, the memory may be used to begin a boot routine.In some embodiments, the control switching system 211 is powered by the power supply interface 214, which may be connected to a battery system, for example. In some embodiments, the power supply interface 214 is connected to or includes an automobile battery (e.g., a 12V lead-acid battery), a DC-DC converter, an AC power supply (e.g., generated by suitably inverting a DC power supply), another power supply, any corresponding components (e.g., terminals, switches, fuses, and cables), or any combination thereof. In some embodiments, the power supply interface 214 provides power to the sensor(s) 240, the tensioning mechanism 220, the locking mechanism 230, any other suitable systems or components, or any combination thereof. In some embodiments, the control circuitry 211, the sensor(s) 240, the tensioning mechanism 220, the locking mechanism 230, or both may be powered by the power supply interface 214.The sensor interface 213 is configured to provide current or other excitation to the sensor(s) 240, receive sensor signals from the sensor(s) 240, condition (e.g., filter, amplify, saturate, convert, or otherwise condition) a sensor signal, modulate a sensor signal, digitize a sensor signal (e.g., an analog-to-digital converter), or a combination thereof. In some embodiments, sensor interface 213 is configured to sample and digitize a sensor signal from sensor(s) 240. In some embodiments, the sensor(s) 240 includes one or more accelerometers, force sensors, pressure sensors, strain sensors, proximity sensors, any other suitable sensors, or any combination thereof. In some embodiments, the control circuit 211 may determine a property value (e.g., an impact value), a voltage, a clamping time, a locking time, or any combination thereof based on one or more sensor signals.The signal generator 215 is configured to generate and transmit signals (e.g., control signals). In some embodiments, the signal generator 215 is configured to generate and transmit digital signals, provide binary signals (e.g., to control relays, switches, contactors, or transistors), provide electrical power (e.g., a DC bus for control signals), transmit or receive any other suitable signals, or any combination thereof. In some embodiments, the signal generator 215 includes a wireless communication interface (e.g., WiFi, Bluetooth, NFC, 4-G), a wired interface (e.g., Ethernet with RJ-45 connectors), an optical interface (e.g., an optical fiber interface), any other suitable interface, or any combination thereof for communicating with other systems or devices (e.g., transmitting signals).The tensioning mechanism 220 (e.g., a pretensioner) includes, as illustrated, an actuator 221 configured to generate tension in response to an event. In some embodiments, actuator 221 is configured to generate voltage in response to a control signal generated by signal generator 215. In some embodiments, the tensioning mechanism 220 is controlled by the control switching system 211 using one or more actuators (e.g., the actuator 221). In some embodiments, tensioning is passive by one or more mechanisms. Actuator 221 may include electromagnetic actuators, pneumatic actuators, hydraulic actuators, chemical-based actuators (such as squibs using solid reactants), spring-assisted mechanisms, any other suitable actuators, or any combination thereof. For example, the actuator 221 may include a firing charge based on shotgun that ignites to force a piston to pull an end of the seatbelt 260, thereby tensioning the seatbelt 260 or a portion thereof (e.g., to eliminate any slack). In another example, the actuator 221 may include a rotary or linear electromagnetic actuator that tensions the end of the seatbelt 260 to eliminate slack (e.g., by applying a predetermined tension or otherwise pulling the end of the seatbelt). Illustratively, the tensioning mechanism 220 may include a spool that, when rotated, tensions the seatbelt 260. For further illustration, the tensioning mechanism 220 may include a linear actuator (such as actuator 221) that pulls the seatbelt 260 using a predetermined or otherwise limited force (e.g., using an energy absorbing element such as that illustrated in FIGS. 3-5 ).The locking mechanism 230 includes, as illustrated, the actuator 231 configured to prevent withdrawal of the seatbelt 260 in response to an event. In some embodiments, the actuator 231 is configured to generate a force (e.g., a clamping force, a latch force) in response to a control signal generated by the signal generator 215. In some embodiments, the locking mechanism 230 includes a ratchet and pawl assembly configured to form a position lock for the seatbelt 260. In some embodiments, the locking mechanism 230 includes a rotary lock or limiter to prevent a spool on which the seatbelt 260 is wound from allowing the seatbelt 260 to be pulled out. Actuator 231 may include, for example, electromagnetic actuators, pneumatic actuators, hydraulic actuators, chemical-based actuators (such as squibs using solid reactants), spring-assisted mechanisms, ratchets or latches, position locks, any other suitable actuators, any other suitable mechanisms, or any combination thereof.FIGS. 3-4 show an example tensioning mechanism and an example locking mechanism in two states according to some embodiments of the present disclosure. In an illustrative example, the mechanism illustrated in FIGS. 3-4 may be the same as or similar to the lower tension member 114 of FIG. 1 or the lower tension member 164 of FIG. 1.FIG. 3 shows a first configuration 300 (e.g., before an event) and FIG. 4 shows a second configuration 400 (e.g., after an event). The configuration 300 corresponds to, for example, a state where the occupant has fastened the seatbelt 301, and a certain slack may be present in the pelvic region. The pawl 310 fixed to the pin 311 functions as a ratchet mechanism with the gear set 320. For example, the length 321 corresponds to a pre-event condition, wherein the structure 302 (e.g., a metal plate comprising the set of teeth 320) cannot move away from the pin 311 anchored to the vehicle. Upon the occurrence of an event, the cable 340 is tensioned (e.g., a force is applied to the cable 340) to eliminate slack in the seatbelt 301 (as shown by the arrow in FIG. 4 ). Configuration 400 corresponds to a post-tightening condition in response to the event. The length of slack in the seatbelt 301 that is eliminated is equal to the difference between the length 321 and the length 422. The pawl 310 engages the set of teeth 320 at another tooth in the second configuration 400, thereby preventing the seatbelt 301 from being elongated.During tensioning, the cable 340 engages the energy absorbing element 330 (e.g., a wire having a double-U shape or other suitable shape). The energy absorbing element 330 is a force / load limiting mechanism configured to absorb energy, limit force, or otherwise reduce the force, impact, or both transmitted from the cable 340 to the structure 302. In some embodiments, the energy absorbing element 330 (e.g., a wire that may undergo elastic or non-elastic deformation) may function as a load limiter and apply a force to the structure 302. In some embodiments, the energy absorbing element 330 applies the same force it receives from the cable 340 to the structure 302 until a force limit is applied. For example, the energy absorbing element 330 may elastically or plastically expand to absorb energy as the force increases beyond the force limit. When the cable 340 pulls (e.g., exerts a force on) the energy absorbing element 330 (e.g., a metal wire, a composite wire, or a wire of any other suitable material), the energy absorbing element 330 engages pins 303 that are rigidly attached to the structure 302. The energy absorbing element 330 pulls pins 303 and structure 302 causing the pawl 310 to ratchet as the gear set 320 moves with the structure 302. Since the pawl 310 only allows the gear set 320 to shorten the belt 301, the belt 301 is more tightly ratcheted when tensioned by the cable 340. The cable 340 and the energy absorption element 330 represent a tensioning mechanism for the structure 302 and thus the seatbelt 301. The pawl 310 and the set of teeth 320 provide a locking mechanism for the structure 302 and thus the seatbelt 301. Any suitable actuator may be used to apply tension to the cable 340, including a motor connected to a pulley assembly, linkage, or other mechanism. As illustrated in configuration 400 of FIG. 4, energy absorbing element 330 is deformed (e.g., plastic) as compared to configuration 300 of FIG. 3. By deforming upon loading by the cable 340, the energy absorbing element 330 (e.g., or any other suitable energy absorbing element) deforms, thereby reducing the force / load transmitted to the structure 302 and thus to the seatbelt 301. As illustrated, the length of the energy absorbing element 330 remains approximately constant as it deforms, although an energy absorbing element may extend (e.g., the element may stretch, buckle, or collapse depending on shape and stiffness), change its shape, or a combination thereof. An energy absorbing element (e.g., energy absorbing element 330) may include a wire, cable, strap, clip (e.g., of a predetermined or otherwise reduced stiffness such that it may deform under load to function as a load limiter), any other suitable element, or any combination thereof. Load limiting, as used herein, refers to reducing a force (e.g., stress) transmitted by a component by deformation (e.g., plastic or elastic), displacement, reconfiguration, or a combination thereof of the component, or other energy absorption of the component.FIG. 5 illustrates an example tensioning mechanism and an example locking mechanism using squibs in accordance with some embodiments of the present disclosure. The system 500 includes the seatbelt 501 secured to the tension member 510, which is shown in enlarged form in the insert. The tension member 510 includes a body 511 connected to the pin 512 which is fixed to the cable 521. The cable 521 is fixed to the piston 523 configured to move inside the cylinder 520. A limit switch 524 is disposed in the cylinder 520. Upon the occurrence of an event, a firing charge is ignited, causing the piston 523 to move as illustrated by the arrow. As the piston 523 moves, it exerts tension on the cable 521, thereby shortening slack in the seatbelt 501. The plunger 523 moves until it abuts the limit switch 524 which then sends a signal over the wire 525 to the squib 515 causing the pawl 516 to engage the ratchet 517 to lock the seatbelt 501. The wire 518 may be included to reduce the tension applied to the structure 511 by the cable 521. The molded body 511 is fixed relative to the seatbelt 501, and when the pawl 516 is engaged with the tooth set 517, the seatbelt 501 is then fixed in length by being fastened to the molded body 511 (e.g., the seatbelt 501 cannot pull out or retract).In an illustrative example, a tensioning mechanism includes a structure (set of teeth 517 including teeth and pin 512) secured to a first end of the seatbelt (e.g., seatbelt 501). An energy absorbing element (e.g., wire 518) is connected to the structure and configured to apply a load limited force. A cable (e.g., cable 521) engages the energy absorbing element and is configured to absorb the load limited force. A mechanism (e.g., piston 523, cylinder 520, and limit switch 524) is configured to apply a first tension to the cable, wherein the load limit allows a second tension less than the first tension to be applied to the structure (e.g., to limit the tension experienced by the occupant). For example, the wire 518 functions as a load limiter configured to receive a first load through the cable 521 but to transmit a decreased load to the pin 512 and thus to the seatbelt 501.In an illustrative example, FIG. 5 relies on a separate actuator for locking the tensioning mechanism, which is illustrative only, and other constructions may be used, such as passive mechanical systems (e.g., spring-assisted ratchet systems or tooth systems). In Fig. 6, an example of a passive system is shown which is based on momentum and spring forces. For example, the impulse of the event may cause the tensioning mechanism to lock after tensioning but before an occupant exerts substantial force on the belt.FIG. 6 shows an upper cross-sectional view of an example latch mechanism in two states, in accordance with some embodiments of the present disclosure. Field 600 shows the locking mechanism in a pre-event configuration. The molded body 611 is connected to the pin 612, which is fixed to the cable 621. The cable 621 is fixed to a tension mechanism. The detent 619 is held in position by the spring 620, thereby blocking the pawl 616 from engaging the set of teeth 617. Upon the occurrence of an event, a change in the pulse causes the latch 619 to move against the spring 620, thereby releasing the pawl 616. The spring 615 exerts a force on the pawl 616, causing the pawl 616 to engage the set of teeth 617 to perform the locking.In an illustrative example, a locking mechanism includes a structure (e.g., tooth set 617 and pin 612 attached to an end of the seatbelt. The structure includes at least one detent (e.g., here, any tooth of the set of teeth 617). The locking mechanism also includes a pawl (e.g., pawl 616 with spring 615 and spring 620) attached to the vehicle and configured to engage the catch to lock the end of the lower portion after the tensioning mechanism removes the slack.FIG. 7 shows front views of multiple example vehicle seats with restraint systems in accordance with some embodiments of the present disclosure. To illustrate, the vehicle seats of FIG. 7 may be similar to the vehicle seats of FIG. 1. panel 700 shows a front view of a system including a seat and a restraint system. The seat includes an upper portion 751 and a lower portion 752. The restraint system includes a strap having an upper portion 761 anchored to an upper module 701 and a lower portion 762 anchored to a lower module 702. In some embodiments, the strap passes through the connector 765, which may include a passage (e.g., a D-loop) and a buckle mechanism (e.g., for engaging the receiver 766 attached to the bottom portion 752 or the vehicle floor). For example, the upper portion 761 and the lower portion 762 may be portions of a single strap that passes through a loop of the connector 765. In some embodiments, the upper portion 761 and the lower portion 762 are separate straps that are each connected to the connector 765. One or both of the lower module 702 and the upper module 701 may include one or more clamping mechanisms (e.g., first and second clamping mechanisms), a locking mechanism, or a combination thereof. For example, one of the lower module 702 and the upper module 701 may include a first tension member that applies tension in a first state (e.g., when installed by the occupant with a lock or a limiter included in one direction), a second tension member configured to shorten a slack in the respective area 762 or 761 in response to an event, and a locking mechanism to prevent withdrawal after the event is detected and the slack is removed.In an illustrative example, an occupant may sit on the lower portion 752 and lean against the upper portion 751. After deployment, the occupant may attach the connector 765 to the receptacle 766 to secure the restraint system. The upper module 701 may exert a first force on the upper portion 761, which in some embodiments may be partially transmitted to the lower portion 762 but need not be transmitted. The lower module 702 may apply a second force to the lower portion 762, which in some embodiments may be partially transferred to the upper portion 761 but need not be transferred. Accordingly, the connector 765 may reduce or prevent tension in one region of the strap from affecting the other region, thereby causing some slack to form in one of the regions.Panel 710 shows a front view of a system including a seat and a restraint system. The seat includes an upper portion 751 and a lower portion 752. The restraint system includes a strap having a portion 715 anchored to the upper module 711. In some embodiments, the strap end includes the connector 765 for engaging the receptacle 766 that is attached to the lower portion 752 or the vehicle floor. The upper module 711 may include one or more clamping mechanisms (e.g., first and second clamping mechanisms), a locking mechanism, or a combination thereof. For example, the upper module 711 may include a first tension member that applies tension in a first state (e.g., when installed by the occupant with a barrier or a limiter included in one direction), a second tension member configured to shorten a slack in the area 715 in response to an event, and a locking mechanism to prevent withdrawal after the event is detected and the slack is removed.Panel 720 shows a front view of a system including a seat and a restraint system. The seat includes an upper portion 751 and a lower portion 752. The restraint system includes a strap having a portion 725 anchored to the lower module 722. In some embodiments, the strap end includes the connector 765 for engaging the receptacle 766 that is attached to the lower portion 752 or the vehicle floor. The lower module 722 may include one or more tensioning mechanisms (e.g., first and second tensioning mechanisms), a locking mechanism, or a combination thereof. For example, the lower module 722 may include a first tension member that applies tension in a first state (e.g., when installed by the occupant with a barrier or a limiter included in one direction), a second tension member configured to shorten a slack in the area 725 in response to an event, and a locking mechanism to prevent withdrawal after the event is detected and the slack is removed.FIG. 8 shows a flow diagram of an example method 800 for tightening and locking, in accordance with some embodiments of the present disclosure. The method 800 may be implemented using, for example, the system 210, the tensioning mechanism 220, the locking mechanism 230, and the sensor 240 of FIG. 2.Step 802 includes achieving a first state. The first condition may correspond to a condition where an occupant has fastened the seatbelt prior to an event. In certain circumstances, the first condition may include the seatbelt being fastened with a first tension in the lower portion and a second tension in the upper portion. Under certain circumstances, equal tension may be applied to the lower and upper portions (e.g., the seatbelt may slide freely relative to an intermediate ring or other passage). In the first state, the lower portion, the upper portion, or both may have a low or zero voltage with some slack. The slack may be caused by an occupant adjustment or other condition.Step 804 includes the system detecting an event. In some embodiments, a vehicle includes one or more sensors (e.g., one or more sensors 240 of FIG. 2 ) for detecting an impact, deformation, or other sign of a collision. The one or more sensors may be connected to a processing unit (e.g., control circuitry 211 of FIG. 2 ) that may execute instructions and generate signals for controlling systems in response to detecting the event. In some embodiments, the sensor includes a force sensor (e.g., for sensing an impact force), an accelerometer (e.g., a piezoelectric transducer), a touch sensor (e.g., based on an impedance), any other suitable sensor, or any combination thereof. For example, in some embodiments, the vehicle or its restraint system includes a control switching system configured to execute instructions to monitor events and, in response to detecting an event, control voltage at step 806 and lock at step 808.Step 806 includes the system performing the tensioning to remove slack in a seatbelt (e.g., using the tensioning mechanism 220 of FIG. 2 ). In some embodiments, the tensioning is controlled by the control switching system using one or more actuators. In some embodiments, tensioning is passive by one or more mechanisms. The actuator(s) may include electromagnetic actuator(s), pneumatic actuators, hydraulic actuators, chemical-based actuators (such as squibs using solid reactants), spring-assisted mechanisms, any other suitable actuators, or any combination thereof. For example, the actuator may include a firing charge based on shotgun that ignites to force a piston to pull an end of the seatbelt, thereby tensioning the seatbelt or a portion thereof (e.g., to eliminate any slack). In another example, the actuator may include a rotary or linear electromagnetic actuator that tensions the end of the seatbelt to eliminate slack (e.g., by applying a predetermined tension or otherwise pulling the end of the seatbelt). Illustratively, the tensioning mechanism may include a spool that, when rotated, tensions the seatbelt. For further illustration, the tensioning mechanism may include a linear actuator that pulls the seatbelt using a predetermined or otherwise limited force (e.g., using an energy absorbing element or other suitable load limiter such as that illustrated in FIGS. 3-5 ).Step 808 includes the system performing locking to prevent seatbelt extension (e.g., using the locking mechanism 230 of FIG. 2 ). In some embodiments, the locking is controlled by a control switching system (e.g., control switching system 211 of FIG. 2 ) using one or more actuators (e.g., as illustrated by locking mechanism 230 in FIG. 2 ). In some embodiments, the locking is passive by one or more mechanisms. Step 808 may include, for example, engaging a set of teeth with one or more corresponding teeth to prevent displacement, exerting a clamping or latching force to prevent displacement, locking a spool on which the seatbelt is wound, another suitable locking technique, or any combination thereof.Step 810 includes the system resetting the tensioning mechanism after the occurrence of the event. In some embodiments, step 810 includes a control circuitry (e.g., control circuitry 211 or signal generator 215 of FIG. 2 ) generating or ceasing generation of a control signal sent to the tensioning mechanism, thereby enabling the tensioning mechanism. In some embodiments, step 810 includes a manual reset wherein a user releases tension on the belt or otherwise resets the tensioning mechanism to the state prior to detecting the event in step 804. In some embodiments, step 810 includes releasing the tension on the lower portion by releasing the tensioning mechanism.Step 812 includes the system resetting the locking mechanism after the occurrence of the event. In some embodiments, step 810 includes a control circuitry (e.g., control circuitry 211 or signal generator 215 of FIG. 2 ) generating or ceasing generation of a control signal sent to the locking mechanism, thereby releasing the locking mechanism and allowing the seatbelt to be pulled out or retracted. In some embodiments, step 812 includes a manual reset wherein a user releases the lock on the strap or otherwise resets the locking mechanism to the state prior to detecting the event in step 804. In some embodiments, step 812 includes unlocking the lower portion by releasing the locking mechanism to allow displacement of the lower portion.In an illustrative example, the system (e.g., system 200 of FIG. 2 ) may include a control switching system connected to the tensioning mechanism (e.g., tensioning mechanism 220 of FIG. 2 ). The control circuitry may be configured to detect the event at step 804 and, in response to the event at step 806, send a control signal to the tensioning mechanism, the control signal causing the tensioning mechanism to apply a voltage.In another illustrative example, the system (e.g., system 200 of FIG. 2 ) may include a control switching system connected to the locking mechanism (e.g., locking mechanism 230 of FIG. 2 ). The control circuit may be configured to detect the event at step 8304 and transmit a control signal to the locking mechanism in response to the event at step 808, the control signal causing the locking mechanism to prevent the seatbelt from being pulled out.In another illustrative example, the system (e.g., system 200 of FIG. 2 ) may include a control switching system connected to the tensioning mechanism (e.g., tensioning mechanism 220 of FIG. 2 ) and the locking mechanism (e.g., locking mechanism 230 of FIG. 2 ). The control circuit may be configured to, in response to the event, send a first control signal to the tensioning mechanism (e.g., the first control signal causes the tensioning mechanism to exert tension) in step 806 and transmit a second control signal to the locking mechanism (e.g., the second control signal causes the locking mechanism to prevent the seatbelt from being pulled out) in step 808.The foregoing is merely illustrative of the principles of this disclosure, and various modifications may be made by those skilled in the art without departing from the scope of this disclosure. The embodiments described above are presented for illustrative purposes and not by way of limitation.

Claims

A system (210) for providing occupant restraint, the system (210) comprising: a seatbelt (260; 301; 501) having an end; a load limiting tensioning mechanism (220) configured to remove slack from the end of the seatbelt (260; 301; 501) in response to an event; and a locking mechanism (230) configured to lock the end of the seatbelt (260; 301; 501) after the tensioning mechanism (220) removes the slack, the tensioning mechanism (220) comprising: a piston (523) and a cylinder (523), the piston (523) configured to move along the cylinder (523); a cable (340; 521; 621) comprising a first end and a second end, wherein the cable (340; 521; 621) is connected at the first end to the seatbelt (260; 301; 501) and is connected at the second end to the piston (523); an igniter charge (515) configured to cause the piston (523) to move along the cylinder (523) to apply tension to the seatbelt (260; 301; 501); and a limit switch (524) disposed at a position along the cylinder (523) and configured to provide a signal when the piston (523) reaches the position along the cylinder (523).The system (210) of claim 1, wherein the load limiting tensioning mechanism (220) comprises: a structure (302; 511) attached to the end of the seatbelt (260; 301; 501); an energy absorbing element (330) connected to the structure (302; 511); a cable (340; 521; 621) engaged with the energy absorbing element (330); and a mechanism configured to apply a first tension to the cable (340; 521; 621), wherein the energy absorbing element (330) enables a second tension to be applied to the structure (302; 511) that is less than the first tension.The system (210) of claim 1, wherein the load limiting tensioning mechanism (220) comprises a wire (525) shaped into a double U-shape.The system (210) of claim 1, further comprising: a connector (115; 165; 765) defining an upper portion (111; 161; 761) of the seatbelt (260; 301; 501) and a lower portion (112; 162; 762) of the seatbelt (260; 301; 501), wherein the lower portion (112; 162; 762) comprises the end and wherein the tensioning mechanism (220) is configured to eliminate slack in the lower portion (112; 162; 762) of the seatbelt (260; 301; 501) from the end.The system (210) of claim 1, wherein the locking mechanism (230) comprises: a structure (302; 511) attached to the end of the seatbelt (260; 301; 501), the structure (302; 511) comprising at least one catch; and a pawl (310; 516; 616) attached to the vehicle (200) and configured to engage the catch to lock the end of the seatbelt (260; 301; 501) after the tensioning mechanism (220) eliminates the slack.The system (210) of claim 1, wherein the locking mechanism (230) comprises: a first member configured to move with the end of the seatbelt (260; 301; 501); a second member configured to engage with the first member; and a pawl (310; 516; 616) configured to engage the second member with the first member to prevent the first member from moving, thereby locking the end of the seatbelt (260; 301; 501) after the tensioning mechanism (220) eliminates slack.The system (210) of claim 1, further comprising a control switching system (211) connected to at least one of the tensioning mechanism (220) or the locking mechanism (230), the control switching system (211) configured to: detect the event; and at least one of: transmit a control signal to the tensioning mechanism (220) in response to the event, the control signal causing the tensioning mechanism (220) to exert tension; or transmit a control signal to the locking mechanism (230) in response to the event, the control signal causing the locking mechanism (230) to prevent the seatbelt (260; 301; 501) from moving in a first direction.A system (210) for providing occupant restraint, the system (210) comprising: a seatbelt (260; 301; 501) having an end; a tensioning mechanism (220) configured to eliminate slack in the seatbelt (260; 301; 501); and a locking mechanism (230) configured to lock the end of the seatbelt (260; 301; 501) after the tensioning mechanism (220) eliminates the slack to prevent lengthening of the seatbelt (260; 301; 501), wherein the first tensioning mechanism (220) comprises: a piston (523) and a cylinder (523), wherein the piston (523) is configured to move along the cylinder (523); a cable (340; 521; 621) comprising a first end and a second end, wherein the cable (340; 521; 621) is connected at the first end to the seatbelt (260; 301; 501) and is connected at the second end to the piston (523); an igniter charge (515) configured to cause the piston (523) to move along the cylinder (523) to apply tension to the seatbelt (260; 301; 501); and a limit switch (524) disposed at a position along the cylinder (523) and configured to provide a signal when the piston (523) reaches the position.The system (210) of claim 8, wherein the seatbelt (260; 301; 501) comprises an upper portion (111; 161; 761) and a lower portion (112; 162; 762), and wherein the tensioning mechanism (220) is configured to eliminate slack in the lower portion (112; 162; 762) of the seatbelt (260; 301; 501).The system (210) of claim 8, wherein the tensioning mechanism (220) comprises: a structure (302; 511) attached to the end of the seatbelt (260; 301; 501); an energy absorbing element (330) connected to the structure (302; 511); a cable (340; 521; 621) engaged with the energy absorbing element (330); and a mechanism configured to apply a first tension to the cable (340; 521; 621), wherein the energy absorbing element (330) enables a second tension to be applied to the structure (302; 511) that is less than the first tension.The system (210) of claim 8, wherein the locking mechanism (230) comprises: a structure (302; 511) attached to the end of the seatbelt (260; 301; 501), the structure (302; 511) comprising at least one catch; and a pawl (310; 516; 616) attached to the vehicle (200) and configured to engage the catch to lock the end of the seatbelt (260; 301; 501) after the tensioning mechanism (220) eliminates the slack.The system (210) of claim 8, further comprising a control circuitry (211) connected to the tensioning mechanism (220), the control circuitry (211) configured to: detect the event; and at least one of: transmit a control signal to the tensioning mechanism (220) in response to the event, the control signal causing the tensioning mechanism (220) to exert tension; or transmit a control signal to the locking mechanism (230) in response to the event, the control signal causing the locking mechanism (230) to prevent the seatbelt (260; 301; 501) from moving in a first direction.The system (210) of claim 10, wherein the energy absorbing element (330) is a wire (518) configured to limit a load transmitted to the seatbelt (260; 301; 501).A method of tightening a seatbelt (260; 301; 501), the seatbelt (260; 301; 501) comprising an end, the method comprising: detecting a vehicle event corresponding to an impact; tensioning the seatbelt (260; 301; 501) using a tensioning mechanism (220) to remove slack, wherein tensioning the seatbelt (260; 301; 501) comprises: moving a piston (523) along a cylinder (520), wherein a cable (340; 521; 621) comprising a first end and a second end is connected at the first end to the seatbelt (260; 301; 501) and is connected at the second end to the piston (523); causing, by an ignition charge (515), the piston (523) to move along the cylinder (523) to apply tension to the seatbelt (260; 301; 501); and providing, by a limit switch (524) disposed at a position along the cylinder (523), a signal when the piston (523) reaches the position; and locking the end using a locking mechanism (230) to prevent displacement of the seatbelt (260; 301; 501).The method of claim 14, wherein the seatbelt (260; 301; 501) comprises an upper portion (111; 161; 761) and a lower portion (112; 162; 762), and wherein tensioning the seatbelt (260; 301; 501) to remove slack comprises tensioning the lower portion (112; 162; 762) to remove slack in the lower portion (112; 162; 762).The method of claim 14, further comprising: reaching a first condition prior to detecting the event, wherein the seatbelt (260; 301; 501) comprises a first tension; and reaching a second condition after tensioning the seatbelt (260; 301; 501), wherein the seatbelt (260; 301; 501) comprises a second tension.The method of claim 16, wherein: in the first state, the seatbelt (260; 301; 501) is slack and the first tension is zero; and in the second state, the second tension is greater than zero.The method of claim 14, wherein tensioning the seatbelt (260; 301; 501) comprises: receiving a first force at an energy absorbing device; and transmitting a second force less than the first force to the seatbelt (260; 301; 501).

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