PRETENSIONER HOUSING IN RETRACTOR ASSEMBLY
A seatbelt pretensioner system for use in a seatbelt retractor assembly having a spindle and a frame includes a housing adapted for being mounted to the frame and having an interior cavity, a pretensioner tube having a first tube end in fluid communication with a gas generator and a second tube end in fluid communication with the interior cavity of the housing, a pinion being rotatably mounted in the housing and fixedly coupled to the spindle adapted for taking up seatbelt webbing during pretensioning, and a pretensioner rod disposed inside the pretensioner tube. Further, the pretensioner rod has a proximal end disposed towards the gas generator and a distal end disposed away from the gas generator. In addition, the housing is formed with at least two levels including an inboard portion and an outboard portion to store the pretensioner rod after pretensioning.
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This present disclosure relates generally to seatbelt restraint devices for restraining an occupant of a vehicle, and more particularly to devices for pretensioning an occupant restraint seatbelt.
BACKGROUNDThe statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Seatbelt restraint systems for restraining an occupant in a vehicle seat play an important role in reducing occupant injury in vehicle crash situations. Seatbelt restraint systems of the conventional so-called “3-point” variety commonly have a lap belt section extending across the occupant's pelvis and a shoulder belt section crossing the upper torso, which are fastened together or are formed by a continuous length of seatbelt webbing. The lap and shoulder belt sections are connected to the vehicle structure by anchorages. A belt retractor is typically provided to store belt webbing and may further act to manage belt tension loads in a crash situation. Seatbelt restrain systems which are manually deployed by the occupant (so-called “active type”) also typically include a buckle attached to the vehicle body structure by an anchorage. A latch plate attached to the belt webbing is received by the buckle to allow the belt system to be fastened for enabling restraint, and unfastened to allow entrance and egress from the vehicle. Seatbelt systems, when deployed, effectively restrain the occupant during a collision or vehicle collision event.
OEM vehicle manufacturers often provide seatbelt restraint systems with pretensioning devices, which tension the seatbelt either during an impact of the vehicle or even prior to impact (also known as a “pre-pretensioner”) to enhance occupant restraint performance. The pretensioner takes out slack in the webbing and permits the belt restraint system to couple with the occupant early in the crash sequence. One type of pretensioner acts on the webbing retractor to tension the belt. Various designs of retractor pretensioners presently exists, including a type known as a roto-pretensioner that incorporates a gas generator activated by a pyrotechnic charge. Generally, ignition of the pyrotechnic charge or other combustible material creates gas pressure in a chamber having a piston to impart motion upon a driving element such as a piston, rack and pinion, polymeric rod, or a series of ball elements disposed in a pretensioner tube, which engages with and wind a retractor spindle sprocket to retract the webbing.
Nowadays, since the vehicle technology is shifted towards highly autonomous vehicles, it is developed that the occupant seats are highly movable and configurable within the interior of the vehicle. In the autonomous vehicle, the occupant seats, which can rotate inside the vehicle drive a need for a seatbelt system that can be mounted to the vehicle seat. Accordingly, the seatbelt system in the autonomous vehicle need to be attached to the seat structure instead of the vehicle body for restraining an occupant sitting on the movable occupant seat. However, we have discovered that the conventional retractor assembly including a pretensioner system cannot be accommodated in a limited space of the seat structure to support the load of the occupant during an impact. The retractor assembly with the pretensioner system mounted to the seat structure should be compact and light-weight, and also support the same load as the conventional seatbelt system mounted to the vehicle body.
SUMMARYThe present disclosure relates to a seatbelt retractor assembly, especially suited for use in an autonomous vehicle (although additional applications are envisioned). The vehicle seats arranged in the interior of the autonomous vehicle are highly movable and configurable. Accordingly, the seatbelt retractor assembly is adapted for being mounted to a seat structure arranged in the interior of the vehicle such that the restraint system having the seatbelt retractor assembly for occupants can move together with the vehicle seat. Further, the seatbelt retractor assembly mounted to the seat structure includes a pretensioner system to tension the seatbelt in an early phase of a vehicle impact, and to maintain the retractor and the seatbelt webbing in a locked condition at the end of the pretensioning such that the seatbelt retractor assembly with the pretensioner system is compact and light-weight, and also supports the load of the occupant during a crash.
In accordance with an exemplary embodiment of the present disclosure, the seatbelt pretensioner system for use in a seatbelt retractor assembly having a spindle and a frame includes a housing adapted for being mounted to the frame, a pretensioner tube having a first tube end in fluid communication with a gas generator and a second tube end in fluid communication with the housing, a pinion having an annular body portion and a protrusion, and a pretensioner rod disposed inside the pretensioner tube and having a proximal end disposed towards the gas generator and a distal end disposed away from the gas generator. The pinion is rotatably mounted in the housing and fixedly coupled to the spindle adapted for taking up seatbelt webbing during pretensioning. Further, the housing includes an inboard portion having the annular body portion of the pinion and an outboard portion receiving the protrusion extending from the annular body portion such that the inboard portion and the outboard portion of the housing store the pretensioner rod after pretensioning.
In accordance with a further aspect of the present disclosure, the inboard portion of the housing includes a circular cavity receiving the annular body portion of the pinion and a guide plate attached to the frame of the retractor assembly. The housing includes an arcuate landing surface formed with a circular path around the circular cavity to guide the pretensioner rod exiting from the pretensioner tube. The inboard portion of the housing receives a portion of the pretensioner tube along the circular path.
In accordance with a further aspect of the present disclosure, the guide plate is disposed opposite an arcuate landing surface in the inboard portion of the housing and formed with a guide path having an inboard end and an outboard end. The guide plate includes a ramped surface formed along the guide path such that the rod moves toward the outboard portion of the housing along the ramped surface.
In accordance with a further aspect of the present disclosure, the outboard portion of the housing is formed with an overflow path to store a portion of the rod moving toward the outboard portion after pretensioning.
In accordance with a further aspect of the present disclosure, the second tube end of the pretensioner tube meets the first end of the arcuate landing surface formed in the housing, and the second end of the arcuate landing surface formed in the housing meets an inboard end of the guide plate disposed in the inboard portion of the housing. Due to the ramped surface of the guide plate disposed in the housing, an outboard end of the guide plate meets the overflow path disposed in the outboard portion of the housing.
In accordance with a further aspect of the present disclosure, after the pretensioner rod exits the pretensioner tube, the rod contacts an arcuate landing surface of the housing around the pinion in the inboard portion and is directed in a guide path having a ramped surface of the guide plate for moving toward the outboard portion such that the rod is stored in an interior cavity formed in at least two levels having the inboard and outboard portions of the housing after pretensioning.
In accordance with a further aspect of the present disclosure, the housing and the guide plate are each made from a casting material.
In accordance with another exemplary embodiment of the present disclosure, the seatbelt pretensioner system further includes a housing adapted for being mounted to the frame and having an interior cavity. The interior cavity of the housing is formed with at least two levels to store the pretensioner rod exiting from the pretensioner tube after pretensioning. The at least two levels of the interior cavity includes an inboard portion and an outboard portion such that the interior cavity of the housing is formed with a spiral shape.
Due to the limited space of the seat frame, the retractor assembly mounted to the seat frame is made with the components having the compact size. So, the seatbelt pretensioner system of the compact retractor assembly mounted to the occupant seat frame is not enough to store the pretensioner rod only in the plane of the pinion arranged in the pretensioner housing because, compared to the retractor assembly mounted to the vehicle body, the size of the compact retractor assembly is relatively reduced. Accordingly, the interior cavity of the housing in the pretensioner system need to be increased to store the pretensioner rod with the other ways such that the housing is formed with at least two levels (planes) along the rotational axis of the pinion, and stores the pretensioner rod in the interior cavity formed with a spiral or helical shape. According to the present disclosure, the compact retractor assembly can be accommodated in the limited space of the seat frame.
Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
DETAILED DESCRIPTIONThe following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.
Referring to the drawings,
The seatbelt webbing 14 is able to pay-out from a retractor assembly 100 (shown in
In
Referring to
During normal operating of the associated vehicle, the retractor assembly 100 allows pay-out of the seatbelt webbing 14 to give the occupant a certain amount of freedom of movement. However, if an impact or a potential impact situation is detected, the retractor assembly 100 is locked to restrict pay-out and to secure the occupant in the vehicle seat 10. For example, if the vehicle deceleration at a predetermined rate or if the brakes are actuated with a predetermined force, then the retractor assembly 100 is locked. Due in part to the free pay-out of the seatbelt webbing 14, the seatbelt assembly 12 often develops slack during normal use.
In accordance with an exemplary embodiment of
As shown in
As will be discussed in further detail below, the pretensioner tube 114 has a pretensioner rod 116, e.g., a plastically deformable polymer rod, disposed therein that has an elongate shape and is flexible within the tube 114. More specifically and as will be discussed in further detail below, the pretensioner rod 116, when disposed outside of the pretensioner tube 114 prior to insertion therein, has a generally a straight shape, and when inserted into the pretensioner tube 114, it will bend and flex in accordance with the bent shape of the pretensioner tube 114, which is fitted inside the limited space of the seat structure.
Further, in
Referring to
In
As shown in
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The pretensioner rod 116 is preferably made from a polymer material, which can be selected to fit the particular desires of the user. The polymer material is preferably one that has sufficient flexibility such that it can bend and flex through the pretensioner tube 114 to allow for initial installation as well as in response to actuation by the gas generator 104. Moreover, the polymer material is selected to enable it to deform and structurally engage with the pretension or pinion during pretensioning operation. The polymer material is preferably one that has sufficient “pushability” (column loading characteristic) in response to actuation, such that the rod 116 will sufficiently transfer a load to the pinion 126 of the pretensioner system 112.
Further, the rod 116 is preferably made from a polymer material that is plastically deformable. During and after actuation, the rod 116 will be become plastically deformed in response to actuation and contact with other components of the pretensioner system 112 (for example, pinion vanes or guide plate). This plastic deformation will be further discussed below with reference to the use of the system 112, where the plastic deformation will cause the system to become locked to prevent or limit payback of the rod 116 without being completely dependent on maintained gas pressure in the pretensioner tube 114. In one approach, the rod 116 is made from a Nylon thermoplastic material. The rod 116 could also be made from an aliphatic polyamide thermoplastic material. In another approach, the rod 116 could be made from a similar thermoplastic material, such as an acetal material or polypropylene material. It will be appreciated, however, that other materials for the pretensioner rod 116 could also be used that can activate the pretensioner system 112 without plastic deformation. For example, an elastically deformable material could be used, but such a material would not provide each of the advantages of a plastically deformable rod.
Referring to
As shown in
Referring to
In
The housing 120 further includes the guide plate 142 disposed in the inboard portion 119. In
Referring back to
Since the retractor assembly 100 according to the present disclosure is sized to fit within the limited space of the vehicle seat 10, compared to the conventional retractor assembly, the size of the retractor assembly 100 is generally compact and decreased. Accordingly, as shown in
As described above, the retractor assembly 100 includes the gas generator 104 (see
As shown in
As shown in
Referring to
In
In addition, the pretensioner tube 114 further includes a mounting bracket 170 attached adjacent to the second tube end 113 to support the tube 114 during the pretensioning. The mounting bracket 170 welded to the outer surface of the tube 114 engages with a slot 143 formed in the PT cup 144. Further, the welded mounting bracket 170 also engages with the frame 106 when the pretensioner system 112 is attached to the frame assembly 107 such that the pretensioner tube 114 is secured and also supported during actuation of the pretensioner or the pretensioning of the seatbelt. Furthermore, the exit portion 168 of the tube 114 includes a T-tab 172 formed in an end of the exit portion 168, which is located in a middle portion between the first end 149 and the second end 151 of the arcuate landing surface 150. As shown in
In an approach, as shown in an example of
During actuation of a pretensioner and during pretensioning of the seatbelt there can be a side-effect known as payback, where the tension on the seatbelt from caused by the occupant during an event triggering pretensioning can rotate the spindle in a direction opposite the pretensioning rotation. This rotation is transferred to the pinion and driving element, causing the driving elements to travel in the reverse direction within the tube. Payback can be counteracted by maintaining pressure in the pretensioner tube, but this requires the gas generator to fire for a longer period and additional propellant.
However, a preferred embodiment of the pretensioner system 112 described herein includes features configured to counteract the above described payback side-effect as an alternative to or in addition to maintained gas pressure. As described above, the rod 116 is preferably made of a plastically deformable material, such as a polymer. Referring back to
Having described the various above embodiments, the general functionality of the pretensioner system 112 will now be described. The pretensioner system 112 has a first, initial, or nominal state, in which the rod 116 is preferably positioned within the tube 114 adjacent the seal 160 and the stopper 162 as shown in
In response to an event or signal that actuates pretensioning, the gas generator 104 will expel gas into the gas chamber. The increased pressure within the chamber will force the seal 160, stopper 162, and rod 116 away from the gas generator 104 and along the path defined by the tube 114. The tapered portion (distal end) 117 of the rod 116 will translate toward the pinion 126, ultimately contacting one of the vanes 138 of the pinion 126 and subsequently a plurality of the vanes 138. The force from the rod 116 exerted against the vane 138 will cause the pinion 126 to rotate about its rotational axis, thereby ultimately winding the seatbelt webbing 14 around the spindle 101 relative to its initial, nominal position. Of course, there are intermediate positions between the first and second positions.
The proximal end of the rod 116 is initially positioned adjacent the seal 160 and the stopper 162 as shown in
During actuation, the seal 160 and stopper 162 will also travel along the tube 114, and the travel of these components assist in driving the rod 116 through the tube 114. In the locked position of the rod 116, the seal 160 and stopper 162 will experience backpressure from the rod 116 as it undergoes resistance contacting the pinion 126. Thus, the seal 160 will have a circumferentially expanded state in the locked position of the rod 116. Further, in instances where the rod 116 travels along the path far enough, the seal 160 and stopper 162 will continue to travel through the tube 114 toward the exit portion 168. Accordingly, due to the stopper 162 having a larger diameter than the inner diameter of the tube end 113, the stopper 162 (also with the seal 160) is prevented from passing through the exit portion 168 of the tube 114 as shown in
While the above description constitutes the preferred embodiments of the present invention, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope and fair meaning of the accompanying claims.
Claims
1. A seatbelt pretensioner system for use in a seatbelt pretensioning retractor assembly having a spindle and a frame, the seatbelt pretensioner system comprising:
- a housing adapted for being mounted to the frame;
- a pretensioner tube having a first tube end in fluid communication with a gas generator and a second tube end in fluid communication with the housing;
- a pinion having an annular body portion and a protrusion extending longitudinally from the annular body portion along a rotational axis of the pinion, the pinion being rotatably mounted in the housing and fixedly coupled to the spindle adapted for taking up seatbelt webbing during pretensioning; and
- a pretensioner rod disposed inside the pretensioner tube, the pretensioner rod having a proximal end disposed towards the gas generator and a distal end disposed away from the gas generator,
- wherein the housing includes an inboard portion having the annular body portion of the pinion and an outboard portion receiving the protrusion extending from the annular body portion such that the inboard portion and the outboard portion of the housing are arranged side by side along the rotational axis of the pinion to store the pretensioner rod after pretensioning.
2. The seatbelt pretensioner system of claim 1, wherein the inboard portion of the housing includes a circular cavity receiving the annular body portion of the pinion and a guide plate attached to the frame of the retractor assembly.
3. The seatbelt pretensioner system of claim 2, wherein the housing includes an arcuate landing surface formed with a circular path around the circular cavity to guide the pretensioner rod exiting from the pretensioner tube.
4. The seatbelt pretensioner system of claim 3, wherein the inboard portion of the housing receives a portion of the pretensioner tube along the circular path.
5. The seatbelt pretensioner system of claim 3, wherein the second tube end of the pretensioner tube meets a first end of an arcuate landing surface formed in the housing, and a second end of the arcuate landing surface formed in the housing meets an inboard end of the guide plate disposed in the inboard portion of the housing.
6. The seatbelt pretensioner system of claim 2, wherein the guide plate is disposed opposite an arcuate landing surface in the inboard portion of the housing and formed with a guide path having an inboard end and an outboard end.
7. The seatbelt pretensioner system of claim 6, wherein the guide plate includes a ramped surface formed along the guide path such that the rod moves toward the outboard portion of the housing along the ramped surface.
8. The seatbelt pretensioner system of claim 6, wherein due to the ramped surface of the guide plate disposed in the housing, an outboard end of the guide plate meets an overflow path disposed in the outboard portion of the housing.
9. The seatbelt pretensioner system of claim 1, wherein the outboard portion of the housing is formed with an overflow path to store a portion of the rod moving toward the outboard portion after pretensioning.
10. The seatbelt pretensioner system of claim 1, wherein after the pretensioner rod exits the pretensioner tube, the rod contacts an arcuate landing surface of the housing around the pinion in the inboard portion and is directed in a guide path having a ramped surface of the guide plate for moving toward the outboard portion such that the rod is stored in an interior cavity formed in at least two levels having the inboard and outboard portions of the housing after pretensioning.
11. The seatbelt pretensioner system of claim 2, the guide plate and the housing are each made from a casting material.
12. A seatbelt pretensioner system for use in a seatbelt pretensioning retractor assembly having a spindle and a frame, the seatbelt pretensioner system comprising:
- a housing adapted for being mounted to the frame and having an interior cavity;
- a pretensioner tube having a first tube end in fluid communication with a gas generator and a second tube end in fluid communication with the interior cavity of the housing;
- a pinion being rotatably mounted in the housing and fixedly coupled to the spindle adapted for taking up seatbelt webbing during pretensioning; and
- a pretensioner rod disposed inside the pretensioner tube, the pretensioner rod having a proximal end disposed towards the gas generator and a distal end disposed away from the gas generator,
- wherein the interior cavity of the housing is formed with at least two levels arranged side by side along a rotational axis of the pinion to store the pretensioner rod after pretensioning.
13. The seatbelt pretensioner system of claim 12, wherein the at least two levels of the interior cavity include an inboard portion and an outboard portion such that the interior cavity of the housing is formed with a spiral shape.
14. The seatbelt pretensioner system of claim 13, wherein the inboard portion includes a circular path formed around the pinion and a guide plate having a guide path such that a portion of the pretensioner rod is stored in the circular path and the guide path after pretensioning.
15. The seatbelt pretensioner system of claim 14, wherein the guide path of the guide plate is formed with a ramped surface to move the pretensioner rod exiting from the tube toward the outboard portion from the inboard portion after pretensioning.
16. The seatbelt pretensioner system of claim 13, wherein the outboard portion includes an overflow path storing a portion of the pretensioner rod.
17. The seatbelt pretensioner system of claim 13, wherein an annular body portion of the pinion arranged in the inboard portion of the housing and a protrusion extending from the annular body portion is rotatably engaged with the outboard portion of the housing.
Type: Application
Filed: Dec 13, 2021
Publication Date: Jun 15, 2023
Applicant: AUTOLIV ASP, INC. (OGDEN, UT)
Inventors: JON E. BURROW (ORTONVILLE, MI), DANIEL ROBERT MURPHY (OXFORD, MI)
Application Number: 17/549,425