Abstract:
Provided is at least one finger that allows securing of various sizes of bolts, undersized or oversized. Flow channels in a compression limiter allow plastic to flow from an outer portion of the compression limiter to a center of the compression limiter to form the angled fingers. The angled fingers allow cheaper manufacture of the compression limiter. The length of the compression limiter may be manufactured using lower tolerances. Also, the inner diameter of the compression limiter does not need an angled step to or tight tolerances, which allows less costly manufacturing of the compression limiter.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 62/048,077 filed Sep. 9, 2014, which is hereby incorporated herein by reference. 
     
    
     FIELD OF INVENTION 
       [0002]    The present invention relates generally to assemblies, and more particularly to a captured fastener apparatus and a method of making the same. 
       BACKGROUND 
       [0003]    Articles having bolt-receiving openings have been used in assemblies for various purposes. Frequently the articles are fastened to other objects or articles by using a nut and a bolt or other metal threaded fastener. Typically, bolts are pre-assembled into a bolt hole in the articles to facilitate bolting the articles to the other objects or articles. A tubular thermoplastic retainer, such as an AXI-RAD®, is often installed on the bolts (or other threaded fastener) and inserted into a compression limiter (e.g., a metal compression limiter) of the articles to secure the bolts to the articles and maintain alignment prior to assembly. 
         [0004]    Typically, the compression limiter is pressed into a bore in the articles and receives the tubular thermoplastic retainer and the bolt. The compression limiter strengthens the article (particularly when formed from plastic) and resists the load that is applied thereto. The integrity of the article, therefore, is not compromised. Additionally, the compression limiter prevents/reduces material creep which can cause reduction of the fastener tightening torque over time. 
         [0005]    Traditional retention mechanisms, like the tubular thermoplastic retainer designs, require multiple assembly steps and tight tolerances to match the size of a corresponding bolt (e.g., a diameter of the retention mechanism must be within ±0.005″ of a diameter of the bolt). A typical tubular thermoplastic retainer design requires inserting the compression limiter into the article, later inserting the bolt into a tubular thermoplastic retainer, and later inserting the bolt and the tubular thermoplastic retainer into the compression limiter to secure the bolt to the article. Tolerances needed to be tight for the article, compression limiter, and tubular thermoplastic retainer. Otherwise, the fastener may be unsecured and/or misalignment may occur, which can lead to added costs due to manual labor required to align the bolt, wasted defective materials, and/or delay. 
       SUMMARY OF INVENTION 
       [0006]    The present disclosure provides a captured fastener apparatus that includes at least one finger for securing various sizes of fasteners, including undersized or oversized fasteners. In forming the at least one finger, flow channels in a compression limiter allow a material, such as plastic, to flow from an outer portion of the compression limiter to a center of the compression limiter to form one or more angled fingers. The one or more angled fingers enable the compression limiter to be manufactured at a reduced cost and/or enable the compression limiter to be manufactured using lower tolerances. Also, an inner diameter of the compression limiter does not need an angled step or tight tolerances, which allows use of less costly manufacturing techniques for the compression limiter. 
         [0007]    According to one aspect of the invention, an assembly component includes a body having a through aperture defined by an interior surface of the body for receiving the shank of a fastener, and at least one resilient finger projecting radially and axially into the aperture for engaging at a free end of the at least one finger the shank of the fastener, and wherein the free end is radially inwardly spaced from the interior surface for defining therebetween a radial gap that allows the free end to flex toward the interior surface for gripping and retaining the shank of the fastener in the aperture. 
         [0008]    The body may include a main body portion formed of plastic and a compression limiter fixed in the body and forming the interior surface, the compression limiter being formed of a material less compressible than main body portion in a region proximate to the compression limiter. 
         [0009]    The main body portion may be over-molded onto the compression limiter. 
         [0010]    The body may include radially inwardly extending anchor portions connected to a base portion of the body. 
         [0011]    The free end may be opposite a proximal end connected to the base portion of the body. 
         [0012]    The compression limiter may have a channel in which a fixed portion of each radially inwardly extending anchor portion is accommodated. 
         [0013]    Each finger may be unitary with the main body portion. 
         [0014]    The base portion may be unitary with each finger. 
         [0015]    Each finger may project radially and axially into the aperture in an unflexed state of the finger. 
         [0016]    The at least one finger may be a plurality of fingers that are circumferentially spaced about the aperture. 
         [0017]    The thickness of each finger may be less than a length of each finger, respectively. 
         [0018]    A circumferential length of each finger may be greater than the thickness of each finger. 
         [0019]    The thickness of each finger may be 5%-25% the length of each finger, respectively. 
         [0020]    The thickness of each finger may be 10%-15% the length of each finger, respectively. 
         [0021]    The assembly component may further include a circumferential spacing between each finger. 
         [0022]    The circumferential length of each finger may be equal to or greater than a circumferential length of each circumferential spacing. 
         [0023]    A component assembly including the assembly component may further include the shank of the fastener held within the aperture. 
         [0024]    A method of securing a fastener to a body of the assembly may include inserting a fastener into the aperture, and the free end of each finger may be resiliently flexed radially and axially to apply a gripping force to the shank of the fastener. 
         [0025]    The compression limiter may include at least one channel for connecting to each finger of the body. 
         [0026]    The compression limiter may include a plurality of channels for connecting to each finger of the body. 
         [0027]    The at least one resilient finger may include a radially inward extending portion. 
         [0028]    The radially inward extending portion may circumferentially span the free end of the finger. 
         [0029]    The foregoing and other features of the invention are hereinafter described in greater detail with reference to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]      FIG. 1  is a perspective view of an exemplary exploded component assembly. 
           [0031]      FIG. 2  is a perspective view of the assembly of  FIG. 1 , with part of the component assembly cut-away to show orientation of components. 
           [0032]      FIG. 3  is a perspective view similar to  FIG. 2 , but with an enlarged view of a single fastener and with part of the component assembly cut-away at a different angle than  FIG. 2 . 
           [0033]      FIG. 4  is a perspective view similar to  FIG. 2 , but with an enlarged view and the fastener being shown transparent to show orientation of components. 
           [0034]      FIG. 5  is a perspective view similar to  FIG. 4 , but with the fastener being shown opaque. 
           [0035]      FIG. 6   a  is a cross-section of the component assembly of  FIG. 1  in an unflexed state. 
           [0036]      FIG. 6   b  is a cross-section of the component assembly of  FIG. 1  in a flexed state. 
           [0037]      FIG. 7  is a perspective view of another exemplary component assembly with a radially inward extending portion for greater retention of a fastener, with part of the component assembly cut-away and the fastener being shown transparent. 
           [0038]      FIG. 8  is a perspective view similar to  FIG. 7 , but with an enlarged view. 
       
    
    
     DETAILED DESCRIPTION 
       [0039]    The principles in accordance with the present disclosure have particular application to assembly components that use fasteners to fasten the assembly components to other portions of a larger assembly, such as a plastic component of a vehicle, and thus will be described below chiefly in this context. It will of course be appreciated, and also understood, that the principles in accordance with the present disclosure may be applicable to other components where it is desirable to secure a fastener to the component. 
         [0040]    Referring now in detail to the drawings, and initially to  FIGS. 1-5 , a component assembly  10  is illustrated. The component assembly includes a body  12  at least partially forming a plurality of fastener mounting features  14  and a fastener  16  for each fastener mounting feature  14 . The component assembly  10  may be a sub-assembly of a larger assembly (not shown) that includes the component assembly  10 . The component assembly  10  is secured, such as bolted, to another component (not shown) of the larger assembly. 
         [0041]    The component assembly  10  can be manufactured inexpensively compared to traditional component assemblies by molding the body  12  and at least part of each fastener mounting feature  14 . Once the body  12  is molded, each fastener mounting feature  14  may receive the fastener  16  without any further assembly processes. Thus, the component assembly  10  requires fewer assembly steps than the prior art (e.g., neither slidably inserting a compression limiter nor slidably inserting a tubular thermoplastic retainer is required). Also, the dimensions of each fastener mounting feature  14  can be manufactured using loose tolerances compared to traditional retention systems to allow further cost reductions with cheaper manufacturing and less wasted time or materials due to an out of tolerance fastener mounting feature  14 . 
         [0042]    Each fastener mounting feature  14  includes a through aperture  20  defined by an interior surface  22  of the body  12  for receiving the shank of the fastener  16  along a longitudinal axis A, radially inwardly extending anchor portions  24 - 27 , a base portion  30  and at least one resilient finger  32 ,  34  projecting radially and axially into the aperture  20 . The aperture  20  allows the fastener  16  to move therethrough for the resilient fingers  32 ,  34  to secure and align the fastener  16  for connection with a separate component (not shown). The entire body  12  may be formed of any suitable material, such as metal or plastic, and may be formed by an injection molding process. 
         [0043]    The radially inwardly extending anchor portions  24 - 27  connect to the base portion  30 . The anchor portions  24 - 27  allow the base portion  30  to be radially inwardly spaced from the rest of the body  12  (excluding the fingers  32 ,  34 ) to form a guide surface for the fastener  16  to reach the fingers  32 ,  34  and a support surface for each finger  32 ,  34 . The radially inward position of the base portion  30  allows the fingers  32 ,  34  to begin radially inward of the interior surface  22 . The anchor portions  24 - 27  may be circumferentially spaced from one another to spread forces between the anchor portions  24 - 27 . For example, in one embodiment the anchor portions  24 - 27  may be equi-circumferentially spaced. In another embodiment the anchor portions  24 - 27  may be asymmetrically circumferentially spaced. In yet another embodiment only one anchor portion may be present. In yet another embodiment the base portion  30  is not radially inwardly offset by an anchor portion. 
         [0044]    The base portion  30  includes a circumferential portion with an axially extending ledge that each finger  32 ,  34  extends from. The base portion  30  may be unitary with each finger  32 ,  34 , which allows the base portion  30  and each finger  32 ,  34  to be molded at the same time. 
         [0045]    Each resilient finger  32 ,  34  projects radially and axially into the aperture  20  in an unflexed state of the finger  32 ,  34 . Projecting radially and axially allows each resilient finger  32 ,  34  to spread radially outward due to forces caused by insertion of the fastener  16 , which reduces the risk of breaking or plastically deforming a resilient finger  32 ,  34 . 
         [0046]    In addition to the illustrated resilient fingers  32  and  34 , hidden from view in  FIG. 1  are two additional fingers with similar shape and orientation. The additional fingers may be arranged opposite the resilient fingers  32  and  34  to form a generally conical boundary spaced about the aperture  20 . Such additional resilient fingers may formed in the same manner and exhibit the same properties and dimensions as resilient fingers  32  and  34 . In an embodiment, the fingers form a through aperture with a diameter having a tolerance between ±0.005″ and 0.025″. Preferably, the tolerance of the diameter is between ±0.010″ and 0.025″. 
         [0047]    Each resilient finger  32 ,  34  is able to flex and exert a gripping force when flexed to allow the fastener  16  to be inserted and secured within the aperture  20 . Securing the fastener  16  allows the fastener  16  to remain aligned relative to the body  12  for later assembly of the body  12  with another component. Each finger  32 ,  34  includes a free end  40 ,  42  opposite a proximal end  50 ,  52  that is connected to the base portion  30 . Each free end  40 ,  42  engages the shank of the fastener  16  and is able to flex radially and axially to receive the shank and exert a gripping force to secure the fastener  16 . For example, the shank may or may not include threaded portions of the fastener  16  and each free end  40 ,  42  may or may not engage the threaded portions of the shank. Alternatively, each free end  40 ,  42  may engage a smooth portion of the shank. 
         [0048]    Each proximal end  50 ,  52  is connected to the base portion  30 , preferably radially outward of the shank of the fastener  16 . Each proximal end  50 ,  52  being radially outward of the shank allows the shank to easily pass through the aperture  20  until a portion of the shank reaches each free end  40 ,  42 . 
         [0049]    Each resilient finger  32 ,  34  may have a thickness less than a respective length and circumferential length, about the longitudinal axis A, of each resilient finger  32 ,  34 . The thickness of each finger  32 ,  34  may be material dependent and nominal wall thickness dependent. In an embodiment, the ratio of thickness to length or circumferential length of each finger is 1:5. As used herein, the circumferential length of each finger  32 ,  34  is a length along arc C, illustrated in  FIG. 4 , about the longitudinal axis A. Forming the finger to have a thickness less than the length allows each resilient finger  32 ,  34  to flex and provide a gripping force to hold the shank of the fastener. In an embodiment, the thickness is between 5% and 25%, preferably between 10% and 15%, the length of each respective resilient finger. The thickness being less than the circumferential length allows each resilient finger  32 ,  34  to bound a larger portion of the shank of the fastener  16  to maintain alignment and increase the gripping force applied to the shank upon insertion into the aperture  20 . 
         [0050]    Each fastener mounting feature  14  may include a spacing  80 - 82  opening axially between adjacent radially outward portions of each resilient finger  32 ,  34 . The spacings  80 - 82  allow the resilient fingers  32  and  34  to move independent of one another. The spacings  80 - 82  also allow greater flexibility for each resilient finger  32 ,  34 . Preferably, the circumferential length of each resilient finger  32 ,  34  is greater than the circumferential length of each spacing  80 - 82 . The greater circumferential length of each resilient finger  32 ,  34  enables greater gripping force to be applied to the fastener  16  and allows better alignment of the fastener  16 . In an embodiment, the circumferential length of at least one resilient finger is equal to or less than at least one corresponding spacing. Each spacing  80 - 82  may extend axially along substantially the entire length of each respective resilient finger  32 ,  34 . In an embodiment, at least one spacing extends less than 90% of the length of at least one resilient finger. In another embodiment, at least one spacing extends less than 25% the length of at least one resilient finger allowing a greater gripping force to be applied to hold the shank of the fastener  16 . 
         [0051]    During use, the fastener  16  is inserted into the aperture  20  and each free end  40 ,  42  of each finger  32 ,  34  is resiliently flexed radially and axially to apply a gripping force to the shank of the fastener  16 . The free ends  40  and  42  may move in a pivoting motion about a respective portion of each finger  32 ,  34  axially closer to the base portion  30 . For example each free end  40 ,  42  may flex in an arcuate path, as shown in  FIGS. 6   a  and  6   b.    
         [0052]    As shown in  FIGS. 6   a  and  6   b , each finger  32  and  34  is angled from the base portion  30  at approximately the same angle in an unflexed state, illustrated in  FIG. 6   a  as 110°. As the fastener  16  slides into position between the fingers  32  and  34  in  FIG. 6   b , the free ends  40  and  42  flex radially and axially outward generally along the provided curved arrows. The flexing decreases the angle, illustrated for simplicity as 105°, between the base portion  30  and each finger  32 ,  34 . Depending on the unflexed shape and orientation of each finger  32 ,  34 , as the one or more fingers  32 ,  34  flex they may bow or arc between the base portion  30  and each free end  40 ,  42 , thus acting as an unsupported end of a loaded cantilever. 
         [0053]    Referring again to  FIGS. 1-5 , flexing the free ends  40  and  42  after insertion allows the fastener  16  to be secured and aligned without another assembly step. The fastener  16  may later be assembled to secure the body  12  with another component after storage, shipping, or simply repositioning to align the body  12  with the other component. 
         [0054]    Each free end  40 ,  42  is radially inwardly spaced from the interior surface  22  for defining therebetween a radial gap  60 ,  62  that allows the free end  40 ,  42  to flex toward the interior surface  22  for gripping and retaining the shank of the fastener in the aperture  20 . Each radial gap  60 ,  62  provides a space for each free end  40 ,  42  to flex into as the fastener  16  is inserted through the base portion  30  into the aperture  20 . In an embodiment, at least one of the free ends is not provided a respective radial gap to prevent the at least one of the free ends from flexing. In another embodiment, a radial gap provides enough space for a free end to flex radially outward of the base portion  30 . 
         [0055]    Each fastener mounting feature  14  may include at least part of a main body portion  70  and a compression limiter  72 . The main body portion  70  may be unitary with each finger  32 ,  34  such that each is made from the same molding. Molding the main body portion  70  and each finger  32 ,  34  together allows overmolding the compression limiter  72  to secure the compression limiter  72  and form the fingers  32 ,  34  in one molding step. The main body portion  70  may be formed of plastic or another moldable material to overmold and bound the compression limiter  72 , which may be formed from metal. Overmolding the compression limiter allows easy manufacturing and lowers assembly time and errors that may occur with an inserted compression limiter  72 . 
         [0056]    The compression limiter  72  is fixed in the main body portion  70  with a radially outward extending ledge  73 . The compression limiter forms an interior surface  74  that extends axially and circumferentially along the interior surface  22  and includes radially extending channels  76 - 79 . Each finger  32 ,  34  allows the interior surface  74  to be axially linear without an interior ledge for supporting a component, such as a tubular thermoplastic retainer. 
         [0057]    The compression limiter  72  is formed of a material less compressible than the main body portion  70  in a region proximate to the compression limiter  72 . Forming the compression limiter  72  of a less compressible material, such as metal allows the compression limiter  72  to reinforce the main body portion  70 , thereby providing a more secure connection between the fastener  16  and another assembly. Further, each finger  32 ,  34  allows the compression limiter to be made using a loose tolerance process such as molding (instead of machine turning), which allows the compression limiter  72  to be formed, for example, from powdered metal. 
         [0058]    Each channel  76 - 79  is equi-circumferentially spaced to accommodate a fixed portion of each anchor portion  24 - 27 . Accommodating the anchor portions  24 - 27  in such manner allows the fastener  16  to exert a gripping force axially against the compression  72  rather than a more compressible portion of the main body portion  70 . Each channel  76 - 79  is formed in an axially facing end of the compression limiter  72 , including an axially facing end of the radially outward extending ledge  73 . In an embodiment, at least one of the channels is formed away from the axially facing end of the compression limiter, such as in an axially intermediate portion of the compression limiter. Alternatively, at least one of the channels may be formed at an axially facing end of the compression limiter opposite the radially outward extending ledge. During manufacturing, each channel  76 - 79  allows moldable material to flow over the compression limiter  72  to form the base portion  30  and the fingers  32  and  34 . 
         [0059]    An advantage of the captured fastener device in accordance with the present disclosure is that assembly time and cost of the larger assembly is reduced by using the component assembly  10 , which allows inexpensively and reliably securing each fastener  16 . Each fastener  16  may be secured with each fastener mounting feature  14  to properly align each fastener  16  with a corresponding fastener receiver (not shown), such as a bolt hole, of the larger assembly. Aligning each fastener  16  allows the component assembly  10  to be easily installed without requiring readjustment of one or more of the fasteners  16  to align with a respective fastener receiver. 
         [0060]    Turning now to  FIGS. 7-8 , another exemplary embodiment of the component assembly is shown at  110 . The component assembly  110  is substantially the same as the above-referenced component assembly  10 , and consequently the same reference numerals but indexed by  100  are used to denote structures corresponding to similar structures in the component assembly  110 . In addition, the foregoing description of the component assembly  10  is equally applicable to the component assembly  110  except as noted below. Moreover, it will be appreciated upon reading and understanding the specification that aspects of the component assemblies may be substituted for one another or used in conjunction with one another where applicable. 
         [0061]    The component assembly  110  includes a body  112  at least partially forming a plurality of fastener mounting features  114  and a fastener  116  for each fastener mounting feature  114 . In an embodiment, only one fastener mounting feature is formed. 
         [0062]    Each fastener mounting feature  114  includes a through aperture  120  defined by an interior surface  122  of the body  112  for receiving the shank of the fastener  116  along a longitudinal axis A, radially inwardly extending anchor portions  124 - 127 , a base portion  130  and at least one resilient finger  132 ,  134  projecting radially and axially into the aperture  120 . 
         [0063]    A feature of the embodiment shown in  FIGS. 7-8  is a radially inward extending portion  190 ,  192  included with each resilient finger  132 ,  134 . The radially inward extending portions  190  and  192  allow greater gripping force to be applied to the shank of the fastener by increasing flexing of each respective resilient finger  132 ,  134  when the fastener  116  is inserted into the aperture  120 . The thickness of the radially inward extending portions  190  and  192  may be about 75% the thickness of each respective resilient finger  132 ,  134 . In an embodiment, the thickness of at least one of the radially inward extending portions is greater than 75% the thickness of the respective resilient finger. In another embodiment, the thickness of at least one of the radially inward extending portions is less than 75% the thickness of the respective resilient finger. The length of the radially inward extending portions  190  and  192  is preferably 5%-25%, more preferably 10%-15%, the length of each respective resilient finger  132 ,  134 . Each radially inward extending portion  190 ,  192  allows a gripping force to be concentrated on a particular area of the shank, such as a threaded portion for enhancing retention of the fastener  116 . In an embodiment, at least one of the radially inward extending portions  190 ,  192  deforms to engage threads on the shank. 
         [0064]    Each radially inward extending portion  190 ,  192  circumferentially spans a respective free end  140 ,  142  of each respective resilient finger  132 ,  134 . Circumferentially spanning each free end  140 ,  142  allows equalizing the gripping force applied to the fastener  116  to better secure and align the fastener  116 . In an embodiment, at least one of the free ends does not include a radially inward extending portion. In another embodiment, at least one of the free ends includes more than one radially inward extending portions. 
         [0065]    Although the invention has been shown and described with respect to a certain embodiment or embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In particular regard to the various functions performed by the above described elements (components, assemblies, devices, compositions, etc.), the terms (including a reference to a “means”) used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiment or embodiments of the invention. In addition, while a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application.