Patent Publication Number: US-2020298792-A1

Title: Energy absorbing restraint systems, such as for use with child seats

Description:
TECHNICAL FIELD 
     The present disclosure is generally directed to energy absorbing occupant restraint systems, such as for use in restraining a child seat in an automobile or other vehicle. 
     BACKGROUND 
     Many types of personal restraint systems are used in automobiles, utility task vehicles (UTVs), and other vehicles. Small children, for example, are typically secured in a portable child seat that can be mounted to a passenger seat in an automobile or other vehicle. The child seat can be secured to the passenger seat by attaching one or more straps, belts, etc., (e.g., webs) from the child seat to corresponding anchor points in the vehicle, and then adjusting the tension in the webs to securely hold the child seat in place. During a crash or other significant dynamic event, substantial loads can be applied to the webs as the vehicle rapidly decelerates. The webs can stretch a small amount and absorb some energy during the crash, but the anchor points in the vehicle are generally rigid and offer little energy absorption. As a result, significant shock loads can be partially transmitted to the child seat during a crash. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A and 1B  are top and side views, respectively, of a restraint system configured in accordance with embodiments of the present of the technology, and  FIG. 1C  is an enlarged cross-sectional side view of a portion of the restraint system taken along the line  1 C- 1 C in  FIG. 1A . 
         FIG. 2A  is a side view of a child seat secured to a vehicle seat with the restraint system of  FIGS. 1A -- 1 C in accordance with embodiments of the present technology,  FIG. 2B  is an enlarged, partially cross-sectional front view of the child seat and the restraint system taken along the line  2 B- 2 B in  FIG. 2A , and  FIG. 2C  is an enlarged, partially cross-sectional front view of the child seat and the restraint system taken along the line  2 C- 2 C in  FIG. 2B . 
         FIG. 3  is an enlarged, cross-sectional side view of the child seat and restraint system of  FIG. 2C  when a tension load is applied to the restraint system in accordance with embodiments of the present technology. 
     
    
    
     DETAILED DESCRIPTION 
     The following disclosure describes various embodiments of energy absorbing systems for restraining child seats. For example, some embodiments of the present technology are directed to a restraint system including a web slide having first and second web apertures. A web can be threaded through the web slide such that the web extends (a) through the first web aperture from a first side to a second side of the web slide and (b) back through the second web aperture from the second side to the first side of the web slide. The web can further be folded and attached to itself to form a joined portion adjacent the second side of the web slide. For example, the web can be attached to itself with frangible stitching to form the joined portion of the web. Upon application of a tension load to the web (e.g., during a crash), the joined portion of the web is pulled taught against the web slide, thereby rupturing the frangible stitching and absorbing a portion of the energy transmitted by the web. 
     In one aspect of the present technology, the restraint system can be used to securely attach a child seat to an anchor point in a vehicle. For example, the web can be coupled to the anchor point, and the web slide can be coupled to the child seat such that the joined portion of the web is adjacent to a front side of a rear wall or panel of the child seat. During a crash or other dynamic event, the joined portion of the web is pulled against the web slide to break the stitching and absorb kinetic energy transmitted by the web to thereby reduce the shock on a child secured in the child seat. 
     Certain details are set forth in the following description and in  FIGS. 1A-3  to provide a thorough understanding of various embodiments of the present technology. In other instances, well-known structures, materials, operations and/or systems often associated with webs, web adjusters, child seats, and other personal restraint system hardware, etc., are not shown or described in detail in the following disclosure to avoid unnecessarily obscuring the description of the various embodiments of the present technology. Those of ordinary skill in the art will recognize, however, that the present technology can be practiced without one or more of the details set forth herein, or with other structures, methods, components, and so forth. 
     The terminology used below is to be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain examples of embodiments of the technology. Indeed, certain terms may even be emphasized below; however, any terminology intended to be interpreted in any restricted manner will be overtly and specifically defined as such in this Detailed Description section. 
     The accompanying Figures depict embodiments of the present technology and are not intended to be limiting of its scope. The sizes of various depicted elements are not necessarily drawn to scale, and these various elements may be arbitrarily enlarged to improve legibility. Component details may be abstracted in the Figures to exclude details such as position of components and certain precise connections between such components when such details are unnecessary for a complete understanding of how to make and use the invention. Many of the details, dimensions, angles and other features shown in the Figures are merely illustrative of particular embodiments of the disclosure. Accordingly, other embodiments can have other details, dimensions, angles and features without departing from the spirit or scope of the present invention. In addition, those of ordinary skill in the art will appreciate that further embodiments of the invention can be practiced without several of the details described below. 
     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  FIG. 1 . 
       FIGS. 1A and 1B  are top and side views, respectively, of a restraint system  100  configured in accordance with embodiments of the present of the technology.  FIG. 1C  is an enlarged cross-sectional side view of a portion of the restraint system  100  taken along the line  1 C- 1 C in  FIG. 1A . Referring to  FIGS. 1A-1C  together, the restraint system  100  includes a first web  102  and a second web  104  coupled together by a web adjuster  106  (e.g., a tilt-lock web adjuster, a push-button web adjuster, etc.) that is operable to adjust the tension in the webs  102 ,  104 . In other embodiments, the web adjuster  106  can be omitted. The webs  102 ,  104  can be any type of flexible web, strap, seat belt web, etc., well known in the art for use with seat belts, child seats, and/or other restraint systems, and can be constructed of various suitable materials known in the art, such as woven nylon. 
     In the illustrated embodiment, the first web  102  includes a first end portion  105   a  and a second end portion  105   b.  The first end portion  105   a  extends through the web adjuster  106  and is configured to be grasped and pulled by a user to increase the tension in the webs  102 ,  104 . The second web  104  is coupled to a hook  108  that can be releasably attached to, for example, an anchor point in a vehicle, More specifically, in the illustrated embodiment the second web  104  includes an attachment loop (e.g., a portion of web material that is formed in a loop and stitched to itself by stitching  101 ) that extends through a web aperture  109  in the hook  108  to couple the second web  104  to the hook  108 . 
     In the illustrated embodiment, the restraint system  100  includes a web slide  110  (e.g., a three-bar slide) having a first side  112   a,  a second side  112   b  opposite the first side  112   a,  a first web aperture  116   a  (e.g., a generally rectangular opening) extending through the web slide  110  between the sides  112   a, b , and a second web aperture  116   b  (e.g., a generally rectangular opening) extending through the web slide  110  between the sides  112   a, b . More specifically, the web apertures  116  are formed between pairs of adjacent crossmembers  114  (identified individually in  FIG. 1C  as first through third crossmembers  114   a - 114   c,  respectively). In other embodiments, the web apertures  116   a, b  can have circular, square, polygonal, irregular, or other shapes, and/or can be positioned differently on the web slide  110 . The web slide  110  can be manufactured using suitable materials and methods known in the art. For example, the web slide  110  can be formed from suitable metal (e.g., steel plate) or composite materials. 
     As shown in  FIG. 1C , the second end portion  105   b  of the first web  102  can be threaded through (i) through the first web aperture  116   a  from the first side  112   a  to the second side  112   b  of the web slide  110  and (b) back through the second web aperture  116   b  from the second side  112   b  to the first side  112  of the web slide  110 . As such, a first length  107   a  of the first web  102  overlays a second length  107   b  of the first web  102  and forms a loop  125 . Additionally, a first portion of the first length  107   a  is attached to the second length  107   b  by first stitching  111  (shown exploded in  FIG. 1C ) to form a first joined portion  122  of the first web  102  that is adjacent to the first side  112   a  of the web slide  110 . Another portion of the length  107   a  is attached to the second length  107   b  by second stitching  120  (shown exploded in  FIG. 1C ; identified individually as first through fifth rows/lines of second stitching  120   a - 120   e ) to form a second joined portion  124  of the first web  102  that is adjacent to the second side  112   b  of the web slide  110 . In the illustrated embodiment, each of the crossmembers  114  is oriented generally parallel to the rows of second stitching  120  as shown in  FIG. 1A , and the rows of second stitching  120  are generally spaced equally apart. The first web  102  further includes a first looped portion  126  between the joined portions  122  and  124  and a second looped portion  128  adjacent to the second joined portion  124 . The first looped portion  126  spans/crosses through the web slide  110  such that the second cross member  114   b  is positioned between adjacent portions of the first and second lengths  107   a, b  of the first web  102  within the first looped portion  126 . 
     The first stitching  111  is configured to maintain the web attachment at the first joined portion  122  even when a tension load is applied to the first web  102 . That is, the first stitching  111  is configured not to break when a tension load is applied to the first web  102 . As described in detail below with reference to  FIG. 3 , the second stitching  120  is configured to rip, break, or otherwise rupture when a shock or tension load is applied to the first web  102  to absorb a portion of the dynamic energy transmitted by the first web  102 . For example, in some embodiments the second stitching  120  can comprise frangible (e.g., rip) stitching that is selected to break when a tension load above a preset magnitude is applied to the first web  102 . In other embodiments, the first web  102  can be attached to itself in other manners to form the first and second joined portions  122  and  124 . For example, one or more clamps, adhesives, etc., can be used to attach the first web  102  to itself to form the joined portions. Likewise, in other embodiments the stitching  111  and  120  can have other suitable arrangements and configurations. For example, the second stitching  120  can include more or less than the illustrated five rows of stitching, and the rows can have different arrangements relative to the web slide  110  (e.g., arranged at angles other than parallel relative to the crossmembers  114 ). Moreover, the rows of second stitching  120  can have different (e.g., irregular) spacings. 
     The restraint system  100  can be used to absorb kinetic energy and reduce shock loads in a wide variety of applications.  FIG. 2A , for example, is a side view of a child seat  230  secured to a vehicle seat  240  (e.g., a seat within an automobile) with the restraint system  100  of  FIGS. 1A-1C  in accordance with embodiments of the present technology. The child seat  230  can be one of any of a number of child seats well known to those of ordinary skill in the art, and can include, for example, a shell  232  having a seat cushion  234  thereon. In the illustrated embodiment, the restraint system  100  securely attaches an upper portion of the child seat  230  to an upper anchor  242  (e.g., a bar) in a vehicle. More specifically, the hook  108  can be attached to the upper anchor  242 , and the web slide  110  can be engaged with to a rear wall or panel  236  of the seat shell  232  as explained in greater detail below with reference to  FIG. 2B . In other embodiments, the hook  108  can be secured to a lower anchor  244  in the vehicle as illustrated in dashed lines in  FIG. 2A . A lower portion of the child seat  230  can be secured to the vehicle seat  240  with additional restraints, such as a restraint  231  of a type well known to those of ordinary skill in the art. 
       FIG. 2B  is an enlarged, partially cross-sectional front view of an upper portion of the child seat  230  and the restraint system  100  taken along the line  2 B- 2 B in  FIG. 2A , and  FIG. 2C  is an enlarged, partially cross-sectional front view of the child seat  230  and restraint system  100  taken along the line  2 C- 2 C in  FIG. 2B . Referring to  FIGS. 2B and 2C  together, the rear wall  236  of the shell  232  can include a rear side  237   a  facing the vehicle seat  240  ( FIG. 2A ), a front side  237   b  opposite the rear side  237   a  and configured to face a child seated in the child seat  230 , and an aperture  238  extending through the rear wall  236  between the sides  237   a, b . In the illustrated embodiment, the aperture  238  is stepped and includes a flange portion  239   a  having a smaller cross-sectional area than a recessed portion  239   b  formed in the front side  237   b  of the rear wall  236 . That is, the flange portion  239   a  of the aperture  238  can be narrower in height and/or width than the second portion  239   b  of the aperture  238 . 
     The web slide  110  is positioned in the recessed portion  239   b  of the aperture  238  such that first web  102  (e.g., the first looped portion  126 ) extends through/past the rear wall  236  of the shell  232 . For example, the web slide  110  can be positioned in the recessed portion  239   b  of the aperture  238  and against the flange portion  239   a  to resist being pulled through the flange portion  239   a  of the aperture  238  in the direction L. In other embodiments, the flange portion  239   a  of the aperture  238  can be omitted and the web slide  110  can be secured directly against the front side  237   b  of the rear wall  236  (e.g., not within a recess therein) with, for example, fasteners, adhesives, etc. In one aspect of the present technology, the restraint system  100  extends through only a single aperture formed in the rear wall  236  of the shell  232 . 
     Accordingly, referring to  FIGS. 2A-2C  together, the second joined portion  124  of the first web  102  is positioned adjacent to the front side  237   b  of the rear wall  236  of the shell  232  of the child seat  230  when the restraint system  100  is installed onto the child seat  230 . As best shown in  FIG. 2C , when the tension in the webs  102 ,  104  is increased (e.g., as indicated by arrow L 1 ), the web slide  110  is pulled against the rear wall  236  of the shell  232  (e.g., against the flange portion  239   a  of the aperture  238 ) and the first web  102  is pulled against the web slide  110 . More specifically, the second crossmember  114   b  of the web slide  110  contacts/engages the first web  102  at or proximate to the second joined portion  124  (e.g., at or proximate to the first row  120   a  of second stitching  120 ). 
     Referring to  FIG. 2C , when a sufficient shock or tension load is applied to the first web  102  (as a result of, e.g., a crash or other rapid deceleration of the vehicle that causes the child seat  230  to jolt forward on the vehicle seat  240 ), the tension force in the first web  102  pulls the first web  102  against the web slide  110  (e.g., against the second crossmember  114   b ) to at least partially separate the first length  107   a  of the first web  102  from the second length  107   b  at the second joined portion  124 , to thereby absorb and dissipate the shock energy transmitted by the first web  102 . More specifically, the tension force can pull the first web  102  against the web slide  110  to rip or break all or a portion of the second stitching  120 . 
       FIG. 3 , for example, is an enlarged, partially cross-sectional side view of the upper portion of the shell  232  of the child seat  230  and restraint system  100  of  FIG. 2C  after a sufficient tension load (e.g., indicated by arrow L 2 ) has been applied to the first web  102  to rip or otherwise rupture the first row  120   a  of the second stitching  120  ( FIG. 2C ). The rupture of the first row  120   a  of the second stitching  120  decreases the length of the second joined portion  124  of the first web  102  while correspondingly increasing the length of the first looped portion  126  as shown in  FIG. 3 . After the rupture of the first row  120   a  of the second stitching  120 , the second crossmember  114   b  engages the first web  102  at or proximate to the second row  120  of the second stitching  120 . 
     If the applied shock or tension load is great enough, subsequent rows of the second stitching  120  can sequentially rupture in a rapid zipper effect, thereby decreasing the length of the second joined portion  124  and dissipating the energy from the crash. After all the second stitching  120  is ruptured, the second looped portion  128  can be pulled against the web slide  110  and form a single looped portion together with the first looped portion  126  that stops any further extension of the first web  102 . The combined rupture of the second stitching  120  and lengthening of the first looped portion  126  can absorb at least a portion of the shock energy during a rapid deceleration event that would otherwise be transmitted to the child seat  230  by the first web  102 —thereby reducing the shock exerted on the child in the child seat  230 . 
     In one aspect of the present technology, by arranging the rows of second stitching  120  generally parallel to the second cross member  114   b  of the web slide, the web slide  110  can apply a consistent force along the rows of second stitching  120  to generally maximize the force each row of the second stitching  120  can absorb before breaking. In another aspect of the present technology, the second crossmember  114   b  is configured to generally apply a force only to the row of second stitching  120  directly adjacent thereto (e.g., the first row  120   a  of the second stitching  120  in  FIG. 2C , the second row  120   b  of the second stitching  120  in  FIG. 3 , etc.). 
     In some embodiments, the restraint system  100  is configured such that the second stitching  120  ruptures when the force applied to the first web  102  is greater than or equal to a preset value or “design-level load.” For example, the restraint system  100  can be configured such that each of the rows of the second stitching  120  rupture at a design-level load of between about 250-500 lbf, and the number of rows of the second stitching  120  can control the overall design-level load for the restraint system  100 . More generally, the shape and size of the rows of second stitching  120 , the thread material type and mechanical properties of the thread and/or other components of the restraint system  100 , and the shape and size of the second crossmember  114   b  can be selected to provide a desired amount of rupture and corresponding decrease in the length of the second joined portion  124  at any of a variety of design-level loads. These and other features can be selected and modified to match or correspond to a calculated design-level load. 
     The foregoing description of embodiments of the technology is not intended to be exhaustive or to limit the disclosed technology to the precise embodiments disclosed. While specific embodiments of, and examples for, the present technology are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the present technology, as those of ordinary skill in the relevant art will recognize. For example, although the restraint systems illustrated in  FIGS. 1A-3  are described in the context of restraining a child seat, those of ordinary skill in the art will understand that the restraint systems described herein can be utilized in a wide variety of other applications utilizing webs as restraints or tethers. For example, the restraint systems of the present technology could be advantageously used in fall-arrest harness systems (e.g., employed at a construction site), recreational utility vehicles (RUVs), automobiles, etc. Accordingly, the restraint systems described herein are not limited to use in any particular restraint system, but can be used with a wide-variety of such systems without departing from the present disclosure. Further, various aspects of the technology described herein can be combined to provide yet other embodiments. 
     Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”. Words using the singular or plural number also include the plural or singular number respectively. Additionally, the words “herein,” “above,” “below,” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application. When the claims use the word “or” in reference to a list of two or more items, that word covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list. 
     From the foregoing, it will be appreciated that specific embodiments of the disclosed technology have been described herein for purposes of illustration, but that various modifications may be made without deviating from the present technology. Certain aspects of the disclosure described in the context of particular embodiments may be combined or eliminated in other embodiments. Further, while advantages associated with certain embodiments of the disclosed technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the disclosed technology. Accordingly, the disclosure and associated technology can encompass other embodiments not expressly shown or described herein. 
     In general, the terms used in the following claims should not be construed to limit the present technology to the specific embodiments disclosed in the specification, unless the above-detailed description explicitly defines such terms. Accordingly, the actual scope of the present technology encompasses the disclosed embodiments and all equivalent ways of practicing or implementing the disclosure under the claims.