The present technology relates generally to prelock prevention devices for use with web retractors, and associated systems and methods.
Seat belt systems for use in automobiles, aircraft, and other vehicles typically include a belt or web that can be pulled from a web retractor and extended across an occupant's body. The web retractor can be fixedly attached to a seat or other mounting structure on one side of the occupant. The free end of the web typically carries a connector tongue that can be releasably engaged with a buckle anchored to the base of the seat or floor opposite the web retractor. Conventional web retractors typically include a spring-loaded, rotatable spool that maintains tension on the web and retracts it when the connector tongue is released from the buckle. Web retractors can also include a locking mechanism that automatically locks the spool during a crash or other significant dynamic event to prevent the web from being extracted and restrain the occupant in the seat.
In certain instances, the locking mechanism can inadvertently lock the spool during a non-crash event. For example, when the occupant releases the web and lets it retract back into the retractor, the connector tongue on the free end of the web can impact the retractor with such force that it causes the locking mechanism to lock the spool. This prevents the occupant or a subsequent occupant from extracting the web for resuse without first having to manually disengage or unlock the locking mechanism.
The present technology is directed to prelock prevention devices for use with web retractors and associated systems and methods. A prelock prevention device configured in accordance with an embodiment of the present technology can include, for example, an arm resiliently supported by a base. The arm can include a contact surface configured to compress a web against a spool of a web retractor to reduce the velocity of the web during retraction. Reducing the web retraction velocity can reduce the impact from a connector tongue striking the web retractor when the web is released by the seat occupant and quickly retracted onto the spool. Decreasing the impact force can prevent the web retractor locking mechanism from inadvertently locking the spool and hindering subsequent web extraction.
Certain details are set forth in the following description and in
Many of the details, dimensions, angles and other features shown in
In the Figures, identical reference numbers identify identical or at least generally similar elements. To facilitate the discussion of any particular element, the most significant digit or digits of any reference number refers to the Figure in which that element is first introduced. For example, element 110 is first introduced and discussed with reference to
The web retractor 100 can be fixedly attached to a vehicle (not shown) by means of bolts and/or other suitable fasteners known in the art. For example, the web retractor 100 can be mounted directly to an interior sidewall of a vehicle, a vehicle floor, a seat frame, and/or other equipment within a vehicle. In the illustrated embodiment, the web retractor 100 includes a frame 130 (e.g., a metal frame) having a mounting flange 108 with one or more apertures 110 configured to receive bolts or other suitable fasteners to fixedly attach the web retractor 100 to a portion of a vehicle.
The web retractor 100 can further include a locking mechanism cover or housing 126 and a spring assembly cover or housing 128 attached to opposing side walls 129 (identified individually as a first sidewall 129a and a second sidewall 129b) of the retractor frame 130. The locking mechanism housing 126 and the spring assembly housing 128 can be attached to the sidewalls 129 of the retractor frame 130 using screws, mating interfaces, snap locks, and/or other suitable attachment means known in the art. The locking mechanism housing 126 and the spring assembly housing 128 can be formed from plastic (e.g., injection-molded plastic) and/or other suitable materials known in the art. The retractor frame 130 can be made from metal (e.g., stamp-formed from a metal sheet or plate, etc.) and/or other suitable materials known in the art.
The retractor 100 also includes a spring-loaded spool 132 that can extend between the sidewalls 129 of the retractor frame 130. The spool 132 is operably coupled to a retractor mechanism (e.g., a torsion spring; not shown) stored within the spring assembly housing 128. The spool 132 carries a seat belt or web 106 (e.g., a lap web, shoulder web, etc.) wound thereon in a known manner. The web 106 can be used to secure an occupant in a vehicle in a conventional manner. For example, the occupant can extract the web 106 from the retractor 100 and releasably engage a connector carried by the distal end portion of the web 106 (not shown in
The spring housing 128 encloses a spring assembly (not shown) generally similar to conventional spool spring assemblies known in the art. For example, the spring assembly can include a biasing member such as a driving coil or spring that is wound concentrically around and coupled to the spool 132. The driving spring can apply a biasing torque to the spool 132, which in turn exerts tension on the web 106 during extraction or pay out, and which drives the spool to retract or take-up the web when the web 106 is released or disengaged from a buckle. The driving spring can be made from an elastic metal (e.g., hardened steel) and/or another suitable material that can store sufficient energy to spring-load and drive the spool 132.
The locking mechanism housing 126 encloses a spool or web locking mechanism (not shown) generally similar to conventional locking mechanisms known in the art that lock or prevent the spool 132 from rotating in the second direction CCW during a crash or other significant dynamic event. For example, the locking mechanism can utilize inertial counterweights (e.g., spring-loaded lever arms) pivotally coupled to the spool 132 and configured to rotate outwardly and engage teeth on a lock ring and lock the spool 132 when the web 106 is extracted from the spool 132 at or above a preset rate (e.g., during a crash or other significant dynamic event). Extracting the web 106 above a preset rate provides a centrifugal force that drives the inertial counterweights outwardly and into engagement with the lock ring, thereby locking the spool 132 and preventing further pay out or extraction of the web 106. This restrains a passenger or occupant in the vehicle seat during a crash or similar event. Those of ordinary skill in the art will understand that prelock prevention devices described herein are not limited to use with any particular locking mechanism configuration or arrangement, and can be used with various other types of locking mechanisms.
In certain instances, the locking mechanism can be inadvertently caused to lock the spool 132. For example, in normal operation of a conventional web retractor, when an occupant releases or disengages the web 106 from a buckle, the spring-loaded spool 132 rotates in the first direction CW to wind the web 106 thereon. In absence of the prelock prevention device 102, the spool 132 can retract the web 106 at a sufficiently high rate of velocity that can, in some instances, cause the connector tongue on the end of the web 106 to strike the web retractor 100 (e.g., the frame 130) with sufficient force to cause the locking mechanism to engage the spool 132 and lock the web 106. For example, the connector tongue can strike the web retractor 100 with a force sufficient to drive the inertial counterweights of the locking mechanism into engagement with the lock ring and lock the spool 132. The occupant or a subsequent occupant will then have to manually disengage the locking mechanism prior to being able to extract and reuse the web 106. For example, the occupant may have to push the web 106 into the retractor 100 to allow the spool 132 to rotate in the first direction CW to allow the counterweights to pivot inwardly and out of engagement with the lock ring. Inadvertently causing the locking mechanism to lock in this manner is commonly referred to as retractor “prelock.”
The prelock prevention device 102 described herein can prevent or reduce the likelihood of retractor prelock. The prelock prevention device 102 can be clipped, clamped, fastened, or otherwise attached to a portion of the web retractor 100 (e.g., the retractor housing 125). For example, in the illustrated embodiment, the prelock prevention device 102 is attached to an edge portion 120 of an opening 112 in the rear wall 127 of the housing 125. In other embodiments, the prelock prevention device 102 can be integrally formed with a portion of the web retractor 100. The prelock prevention device 102 can be fitted (or retrofitted) to virtually any type of web retractor.
In the illustrated embodiment, the first flange portion 216 can be resiliently biased toward the second flange portion 218 when the base 214 is installed on the edge portion 120 of the rear wall 127 (
The second flange portion 218 (and/or the first flange portion 216) can include at least one barb feature 246 (e.g., an angled or sharp projection) on a distal end portion thereof. The at least one barb feature 246 can help further secure the prelock prevention device 102 to the web retractor 100. For example, due to vehicle movement and/or normal operation of the web retractor 100, both the web retractor 100 and the prelock prevention device 102 may have a tendency to move relative to each other. This can cause the base 214 to back off of the edge portion 120. The least one barb feature 246 can dig into or bear against the rear wall 127 to prevent or reduce back-out and secure the prelock prevention device 102 relative to the web retractor 100.
The prelock prevention device 102 includes an arm 224 resiliently supported by the base 214. For example, the arm 224 can be cantilevered from the base 214 in a reverse direction by a second bight portion 238 (e.g., a generally U- or V-shape). The base 214, the second bight portion 238, and the arm 224 can form a second generally V-shaped or U-shaped cross-section of the prelock prevention device 102. The second generally V-shaped or U-shaped cross-section can be larger than the first generally U-shaped cross-section formed by the first flange portion 216, the second flange portion 218, and the first bight portion 236.
The arm 224 further includes a contact surface 234 on a distal end portion 252 that is configured to compress the web 106 against the spool 132 (
Referring to
In operation, the prelock prevention device 102 increases the pressure on the web 106, and hence the friction, proportional to the diameter of the wound web. Hence, the closer the web 106 is to being fully retracted, the greater the pressure. As more of the web 106 is retracted, more of the web is taken-up or wound onto the spool 132. The wound web drives the contact surface 234 toward the base 214, thereby increasing the pressure on the web 106.
When the occupant 360 releases or disengages the connector tongue 367 from the buckle 369, the web 106 is retracted into the web retractor 100 and wound onto the spool 132 as described above. The prelock prevention device 102 reduces the web retraction velocity by bearing against the web 106 with increasing force to provide a frictional force that is counter to the direction of web travel, thereby reducing the impact force of the connector tongue 367 striking the web retractor 100. This reduces or prevents the locking mechanism of the web retractor 100 from locking the spool 132. The occupant 360 or subsequent occupant can then freely extract the web 106 from the web retractor 100 across their body for reuse by extending the web 106 and reengaging the tongue 367 with the buckle 369.
Although
From the foregoing, it will be appreciated that specific embodiments have been described herein for purposes of illustration, but that modifications may be made without deviating from the spirit and scope of the various embodiments of the present technology. Specific elements of any of the foregoing embodiments can also be combined or substituted for elements in other embodiments. Furthermore, while advantages associated with certain embodiments of the present technology have been described in the context of these embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the technology. Accordingly, the present technology is not limited, except as by the appended claims.