Abstract:
A fastener assembly for floatingly retaining or captivating at least one fastener is disclosed. The fastener assembly includes a flexible channel member with discrete projections extending from opposed flange portions towards each other and at least one fastener having a base which is captivated between the discrete projections and a web portion of the channel member. The projections extending from at least one flange portion are configured to present a camming surface to a fastener base as it is being inserted into the channel member through the opening between opposed projections to cause the channel member to elastically flex and to move at least one flange portion outwardly to permit the fastener base to be seated in the channel member through the opening. The projections are further configured to present removal of the fastener base from the channel member through the opening as long as the channel member remains unflexed.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a retainer assembly for at least one fastener, for example, a nut or a bolt, in which the fastener is floatingly retained or captivated within a channel member, and to a clamping system which includes complementary fastener retainer assemblies. 
     Nut and bolt retainers in which the nuts or bolts are captivated or held in a channel member with one or more directions of limited movement relative thereto are known in the prior art. For example, my prior U.S. Pat. No. 4,488,844, which issued Dec. 18, 1984, discloses a floating fastener retainer assembly including a channel member having a web portion and two spaced flange portions extending from the same side of the web portion. Each of the flange portions has an edge turned in toward the opposite flange portion so that the inturned flange edges define an opening into the channel member. The channel member and the base of each fastener are sized so that each fastener base when positioned in the channel member between the web portion and the flange portions and beneath the inturned flange edges is floatingly captivated and can not be removed through the opening between the inturned flange edges while the channel member is unflexed. 
     In order to facilitate insertion of fastener bases into the channel member through the opening between the inturned flange edges, each fastener base is configured, as disclosed in my above-mentioned U.S. Patent, to include an inclined portion on at least one of the side surfaces thereof which faces a flange portion when the fastener base is captivated in the channel member. The flexibility of the channel member, the size of the opening between the inturned flange edges, the size of the fastener base and the inclined portion of each fastener base side enable the respective fastener base to be inserted into the channel member through the opening between the inturned flange edges when the channel member is flexed. A slot in the side of each fastener base, which may be engaged by the tip of a screwdriver, facilitates removal of the fastener base through the opening between the inturned flange edges upon flexing of the channel member by the screwdriver. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a floating fastener retainer assembly which can be manufactured relatively easily at low cost. 
     It is another object of the present invention to provide a clamping system comprising complementary floating fastener retainer assemblies which can be manufactured relatively easily at low cost. 
     In accordance with the present invention, there is provided a fastener assembly including at least one floatingly captivated fastener, the assembly comprising a channel member having a web portion and spaced flange portions extending from the same side of the web portion, and for each captivated fastener, at least one discrete projection extending from at least one of the flange portions over the base of a captivated fastener towards the other flange portion. Each fastener base and the channel member (including at least one discrete projection for each fastener) are configured and sized so that the respective fastener base can be captivated in the channel member (when unflexed) between the flange portion thereof below at least one respective discrete projection with limited movement of the respective fastener base relative to the channel member. 
     Each discrete projection extending from at least one of the flange portions for captivating a respective fastener is configured and sized and the flange portions are sized for facilitating insertion of the fastener base into the channel member through an opening thereto between a projection or projections on one flange portion and the opposed flange portion (when projections are provided on only one flange portion) or between projections on opposite flange portions (when projections are provided on both flange portions). 
     Thus, each projection extending from at least one of the flange portions over a respective captivated fastener base is configured and positioned to both facilitate insertion of a fastener base into the channel member through the opening thereto and captivate the fastener base in the channel member, i.e. prevent the fastener base from simply falling through the opening or from simply being lifted out of the channel member through the opening. Further, the fastener base is configured for facilitating its removal from the channel member through the opening thereto. 
     In one embodiment of the fastener assembly, for each fastener to be captivated, at least one projection extends from each flange portion into the opening to the channel member, the opening being defined by the space between the projections on opposite flange portions. Each projection extending from at least one of the flange portions over a captivated fastener base is configured to act as a camming surface for a fastener base being inserted into the channel member which causes elastic flexing of the channel member so that at least one of the flange portions moves outwardly sufficiently to allow the fastener base to be inserted into the channel member beneath the projections through the opening to the channel member. In a preferred embodiment, for each fastener to be captivated, two projections extend from each flange portion towards the other flange portion, and the projections extending from at least one of the flange portions are tapered or sloped, linearly or arcuately, so that they are thicker nearer the web portion of the channel member. The sloped surfaces each act as the above mentioned camming surface by means of which the base of the fastener elastically flexes the channel member so that at least one of the flange portions moves outwardly as the fastener base is inserted into the channel member through the opening thereto. 
     The fastener base, which is defined by opposed sides, is inserted into the channel member by disposing one side of the base between the projections extending from one flange portion and the web portion, and resting the opposite side of the fastener base on the sloped surfaces of the projections extending from the opposite flange portion. Thereafter, the fastener base is pressed towards the web portion with a relatively small force, which causes a camming action between the fastener base and the tapered projections in contact therewith to elastically flex the channel member so that at least one of the flange portions moves outwardly a distance sufficient for the fastener base to clear the projections. 
     The configuration of the fastener base which facilitates its removal from the channel member through the opening thereto preferably includes structure which can be engaged by an implement such as the tip of a screwdriver, for example. The implement is pivoted to then also engage it with one of the flange portions and further pivoted to elastically flex the channel member so that at least the engaged flange portion moves outwardly a distance sufficient for the base of the fastener to clear the projections extending from that flange portion. The fastener base is then pivoted by the implement so that one end moves out of the channel member thereby freeing the fastener from captivation. The structure associated with the fastener base for facilitating removal takes, in one embodiment, the form of a cut-out or slot in a side of the fastener base facing a flange portion when the fastener is captivated. 
     According to the invention, complementary fastener assemblies as described above may be provided as a clamping system for clamping two adjacently-positioned objects together. One complementary fastener assembly may be, for example, a nut retainer assembly and the other a bolt retainer assembly. 
     The above and other objects, features, aspects and advantages of the invention will be more readily perceived from the following description of the preferred embodiments of the invention taken in conjunction with the accompanying drawings and appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings in which like references indicate like parts, and in which: 
     FIG. 1 is a partially exploded, front perspective view of a portion of a nut retainer assembly according to the invention; 
     FIG. 2 is a top plan view of the portion of the nut retainer assembly depicted in FIG. 1; 
     FIG. 3 is a top plan view on a reduced scale of the channel member of the nut retainer assembly depicted in FIG. 1; 
     FIG. 4 is a cross-sectional view on an enlarged scale of the nut retainer assembly of FIG. 1 without a captivated nut taken along line 4--4 in FIG. 1; 
     FIG. 5 is a cross-sectional view similar to that of FIG. 4 depicting insertion of a nut into the channel member of the nut retainer assembly; 
     FIG. 6 is a cross-sectional view similar to that of FIG. 4 depicting the nut after it has been seated in the channel member of the nut retainer assembly; 
     FIG. 7 is a cross-sectional view similar to that of FIG. 4 depicting removal of the nut from the channel member of the nut retainer assembly. 
     FIG. 8 is a side perspective view of complementary fastener retainer assemblies clamping two longitudinal edges of a split cylinder; and 
     FIG. 9 is a cross-sectional view on an enlarged scale of the complementary fastener retainer assemblies depicted in FIG. 8 taken along line 9--9 in FIG. 8. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings in detail and specifically to FIGS. 1-3 there is shown an illustrative embodiment of the invention in the form of a nut retainer assembly 20. Nut retainer assembly 20 includes a channel member 22 and nuts 24 captivated therein as depicted in FIGS. 1, 2, and 6. Channel member 22 includes a web portion 26 and two confronting spaced apart flange portions 28 and 30 extending from the same side of web portion 26. Nuts 24 each include an elongated threaded hole 33 which may receive the threaded shank of a respective bolt (not shown) passing through a respective hole 34 (FIGS. 3 and 6) in web portion 26. For each nut 24 to be captivated, web portion 26 includes two lances or tabs 36 (FIG. 3), one on each side of the captivated nut (FIG. 2). Pairs of lances 36 are associated with each hole 34 in web portion 26, one on each side of a respective hole as depicted in FIG. 3. The lances of a pair are spaced to limit movement of nuts 25 longitudinally within the channel member 22 (see FIG. 2) while providing alignment of the holes 33 in nuts 24 with the holes 34 in web portion 26 (FIG. 6). 
     Flange portions 28 and 30 each have, for each nut 24 to be captivated, two discrete projections 38 extending towards the other flange portion. In that embodiment, the opening 40 (FIG. 2) to the channel member extends between a pair of opposed projections 38. Projections 38 are preferably formed by inwardly projecting lances or tabs in the flange portions which can be made when channel member 22 is manufactured, or can be made using conventional methods subsequent to manufacture of a smooth continuous channel member 22. Although two pairs of opposed projections 38 are provided for each nut to be captivated in the embodiment depicted in the drawings, more or fewer projections in various dispositions may be employed. 
     While structure such as lances 36 are presently preferred for limiting longitudinal movement of nuts captivated in channel member 22, other structure may be used to accomplish that function. For example, the boss or hub 41 of threaded hole 33 of a nut may be configured to extend between and be engaged by a pair of projections 38 to longitudinally captivate the nut in the channel member while permitting limited longitudinal movement of the nut. The boss 41 of the threaded hole (see FIG. 1) may be extended towards nut side 50 opposite nut side 48 in any desired shape (e.g. rectangular or curved) to extend between a pair of projections 38. Alternatively, the holes 34 in web portion 26 of channel member 22 may be off-set to one side and holes 33 in the nuts may be correspondingly offset such that the boss 41 of hole 33 of each nut extends between a pair of projections 38 and is engaged thereby as described above. If desired, the bosses 41 of holes 33 and the off-set locations of holes 33 and 34 may cooperate to longitudinally captivate respective nuts between respective pairs of projections 38. 
     As depicted in FIGS. 1 and 3, when each of the bases 42 of nuts 24 is seated in the channel member 22 between adjacent tabs 36 and between the web portion 26 and projections 38, each nut 24 is &#34;captivated&#34; and has only limited movement in any direction. Such limited movement simplified alignment and threading of a bolt (not shown) with the nut 24. 
     Projections 38 are configured to facilitate insertion of nut bases 42 through opening 40 into channel member 22. In the preferred embodiment depicted in the drawings, projections 38 each include an outer surface 43 (see FIGS. 4 and 5) which generally linearly slopes downwardly towards the flange portion opposite the one that the respective projection extends from. As described in more detail below, sloping surface 43 acts as a camming surface for a nut base 42 to cause the channel member to elastically flex such that at least one of the flange portions 28, 30 moves outwardly during insertion of a nut base 42 into the channel member through opening 40. Although projections 38 are depicted in the drawings to have a generally linearly sloping camming surface 43, other configurations of projections 38 may be employed to act as a camming surface or otherwise facilitate insertion of nuts 24 into the channel member while also providing structure to captivate the nut in the channel member. Such configuration may be provided for projections on only one or both flange portions for each nut to be retained in the channel member. 
     Insertion of one of nut bases 42 into the channel member 22 is described below with reference to FIGS. 4, 5 and 6. The base 42 of each nut 24 (FIG. 1) is defined by opposed spaced apart faces 44 and 46 and sides 47, 48, 49 and 50. Sides 47 50 are defined broadly and refer not only to the surfaces extending between faces 44 and 46, but also to the intersections of those surfaces with faces 44 and 46, and also to the portions of faces 44 and 46 adjacent those surfaces. When seated in channel member 22 (FIG. 6), nut base side 48 and 50 face respective flange portions 30, 28. FIG. 5 shows the initial position of nut 24 for inserting it into the channel member 22. Side 50 is placed between projections 38 of flange portion 28 and web portion 26 while nut base side 48 rests on the sloped surface 43 of the projections 38 on flange portion 30. As indicated by the curved arrows in FIG. 5, a force is applied to nut base 42 which results in a camming action between the inclined surfaces 43 and the nut base to cause the channel member to elastically flex such that flange portion 30 primarily moves outwardly, thereby allowing side 48 of the nut base 42 to move below projections 38 on that flange portion. 
     FIG. 6 shows nut 24 subsequent to FIG. 5 after nut base 42 has been seated in channel member 22. Hole 33 in the nut 24 is generally aligned with the larger hole 34 in web portion 26 to provide access to the hole 33 from the side of the web portion opposite opening 40 thereto. It will be appreciated from the disclosure herein that the dimensions of the nut base 42, the spaces between the flange portions, the configuration and location of the projections, and the relative flexibility of the channel member are interrelated at least to a certain extent, and are selected to permit insertion of nuts into channel member 22 and captivation thereby as disclosed herein. 
     Nut 24 is configured to facilitate its removal from channel member 22 through opening 40. Referring to FIG. 1, a preferred configuration for this purpose includes a recessed or cut-out portion 54 in, for example, side 48. As illustrated in FIG. 7, a lever-like implement such as tip 55 of a screwdriver (shown partially) is used to pivot side 48 upwardly from web portion 26 past projections 38 on flange portion 30 as the channel member is elastically flexed to move that flange portion away from the opposite flange portion 28, thereby unseating nut base 42 from channel member 22 through opening 40 thereto. 
     The dimensions of the nut retainer assembly 20 depend, in part, on the materials used and the amount of floating movement which is desired or will be tolerated for nuts 24. If the channel member 22 is being used primarily to retain nuts 24 and is not intended to play a significant role in distributing forces along the length of web portion 26, then channel member 22 may be made of a relatively thin and lightweight material such as aluminum or plastic or the like. If, however, nut retainer assembly 20 will be used to provide a substantial force-distributing function, then channel member 22 is preferably made of a strong material such as iron or steel or the like. Nuts 24 may be made of plastic or metal, depending upon the end application in which nut retainer assembly 20 will be used. 
     FIG. 8 depicts a clamping system 60 for clamping, for example, a longitudinally split cylinder 62 having edge flanges 64 and 66 compressed between complementary fastener assemblies 20 and 70. Referring to FIG. 9, fastener assembly 20 holds nuts 24 and fastener assembly 70 holds complementary bolts 72 by means of bolt retainers 74. Bolt retainers 74 are dimensioned similar to the base 42 of nut 24. Each bolt retainer 24 has a bore 76 having a larger diameter than the shank 78 of the bolt 72. An annular washer 80 is used to frictionally retain bolt 72 in bore 76. The annular washer 80, which is of a conventional design and material and may be composed of natural or synthetic rubber or any other appropriate material, frictionally engages shank 78 of bolt 72 in bore 76 of bolt retainer 74. Although FIG. 9 shows bolt 72 captivated by means of retainer 74, a bolt (not shown) having a head configured similar to the outside of retainer 74 can be captivated directly. 
     Although the invention herein has been described with reference to particular embodiments, it is to be understood that those embodiments are merely illustrative of the principle and application of the invention. Thus, it is to be understood that numerous modifications may be made in the illustrated embodiments and other arrangements may be devised without departing from the spirit and scope of the invention. 
     Protection by Letters Patent of this invention in all its aspects as set forth in the appended claims is sought to the full extent that the prior art allows.