Multi-vehicle retention grommet

[0001] Vehicle floor covers, such as floor mats and floor trays, are commonly available to protect the underlying vehicle carpeting and to facilitate removal of water, dirt and debris from the foot wells of the vehicle. Due to the danger of interference with the gas and brake pedals, at least the floor cover provided for the driver's side must be secured in place within the driver's side foot well. Many vehicle manufacturers secure their floor covers by employing retention posts, which are affixed to the foot well, in combination with holes in the floor covers. Many of these studs or posts have a shaft of limited diameter that terminates in an enlarged head.

[0002] Retention post sizes vary among makes and models of vehicles. In addition, a hole in a floor cover doesn't always provide the secure fit desired for a floor cover. A grommet may be used to engage the retention post and floor cover in a tighter, more secure manner. A grommet that fits many retention posts would be able to be used in multiple makes and models of vehicles.

[0003] According to one aspect of the invention, a vehicle floor cover retention grommet includes a bottom grommet and a top grommet. The bottom grommet is formed around an axis and has a floor cover retention flange that radially outwardly extends from the outer surface of an upstanding outer sidewall. The outer sidewall upwardly extends to a hinge plane, which may be collocated with the top of the outer sidewall. The top or hinge plane of the bottom grommet may have an annulus that extends radially inwardly from the outer sidewall to an inner end of the hinge plane. Several fingers have respective upper ends that join to the inner end of the annulus and extend downwardly to respective finger lower ends. Each finger has a bead near its lower end that radially inwardly extends from a more general inner sidewall surface of the finger. In combination with the other fingers, this bead is adapted to engage a vehicle foot well retention post head of any of several types with an interference fit. A top grommet is provided that fastens to an outer surface of the outer sidewall of the bottom grommet.

[0004] According to another aspect of the invention, a vehicle floor cover grommet is provided that has a bottom grommet and a top grommet. The bottom grommet has an outer sidewall formed around an axis. A floor cover retention flange radially outwardly extends from the outer surface of the outer sidewall. The outer sidewall extends axially upwardly from the retention flange to a top plane of the bottom grommet. The outer sidewall has an inner surface. Plural fingers, integrally formed with the outer sidewall, are radially inwardly spaced from the inner surface of the outer sidewall, and are angularly spaced apart from each other. Each finger has a lower end axially and downwardly spaced from the top plane of the outer sidewall. Each finger has a bead disposed near its lower end. Each bead has an innermost margin and an inclined surface which extends upwardly and outwardly from the innermost margin of the bead to a general inner sidewall surface of the finger. This inclined surface is adapted to engage, with an interference fit, the enlarged heads of each of several types of retention posts. A top grommet is adapted to fasten to the outer surface of the outer sidewall of the bottom grommet.

[0005] In either of the above embodiments, the bottom grommet may be further provided with a plurality of spaced-apart vertical ribs. These ribs are angularly spaced around and are in alignment with the axis; each vertical rib is disposed between neighboring fingers. The fingers have inner sidewall surfaces that conform to an imaginary cylinder, a diameter of which is preselected to be larger than the largest type of post head that the grommet is designed to accommodate. The vertical ribs each extend, radially inwardly, from the inner surface of the bottom grommet outer sidewall to the imaginary cylinder. These ribs resist lateral movement of the grommet relative to the retention post once the grommet has been snapped over the post.

[0006] Alternatively or in addition, each finger of the bottom grommet may be provided with a reinforcing rib that is aligned with the axis and that extends from an inner surface of the outer sidewall of the bottom grommet to an outer sidewall surface of the finger. An angular extent of the reinforcing rib, relative to the axis, is much smaller than an angular extent of the finger for which it is provided to brace, such as being one-fourth or less of the angular extent of the finger proper.

[0007] A principal technical advantage of one embodiment of the invention is that the inclined plane of each finger bead provides an extensive surface, different points of which can engage different enlarged post head structures with an interference fit. This in turn permits the use of the grommet with floor covers for many makes and models of vehicles. The provision of a single grommet for multiple vehicle types reduces the overall manufacturing, tooling, research and development costs for the vehicle floor mats and trays fitted with the grommets.

[0021] As described above, the present invention provides a grommet that engages any of several vehicle foot well retention posts or studs. As seen in FIG. 1, grommets according to the invention have two components: a retention or bottom grommet 106 and a top grommet or cap 108. A retention or bottom grommet 106 is axially aligned with a vehicle foot well retention post or stud 102, a portion of a vehicle floor cover 104, and a top grommet or cap 108. The vehicle floor cover retention stud 102 protrudes through the original equipment manufacturer (OEM) vehicle carpet 111 and is formed around an axis X. Axis X typically is vertical but, in some vehicle foot wells, may be canted away from the vertical. Stud or post 102 may have an extensive base 109 that in use is disposed underneath the OEM carpet layer 111.

[0022] The function of the vehicle floor cover 104 is to protect this OEM carpet or surface 111, and provide an easy way for the vehicle owner to keep the vehicle foot well clean; the owner (or other user, or attendant) removes the vehicle floor cover, washes it off, and replaces it in the foot well. The vehicle floor cover 104, which can be a floor mat or a floor tray, has a floor cover retention hole 110 into which the bottom grommet 106 protrudes from below. Often there are two laterally spaced-apart studs or posts and floor cover retention holes 110, typically located near the aft outboard and aft inboard corners of the foot well and floor cover, but only a representative one of them is shown in FIGS. 1 and 5-5C.

[0023] The bottom grommet 106 may be integrally molded from a polymeric material, such as nylon or other suitable material. The bottom grommet 106 engages an enlarged head 112 of the vehicle floor cover retention stud or post 102. The vehicle floor cover retention stud 102 may have the shape of the stud illustrated in FIG. 1, or may be of a myriad of other shapes depending on the make and model of the vehicle; four such shapes are shown in FIGS. 5-5C, discussed below. In the illustrated embodiment, the bottom grommet 106 extends through the floor cover retention hole 110 and a top grommet or cap 108 is attached to the bottom grommet 106, as by being snapped over the bottom grommet's outer sidewall.

[0024] In the illustrated embodiments the top grommet 108 downwardly extends through most or all of the retention hole 110, as will be hereinafter described. The top grommet 108 may be integrally molded from a polymeric material, such as nylon, or other suitable material. In the illustrated embodiment the top grommet 108 has a solid top or cap 114 that completely covers floor cover hole 110 and bottom grommet 106. Alternative embodiments of the top grommet 108 may have an open top or partially open top 114.

[0025] As seen in FIG. 2, the bottom grommet 106 has an outer sidewall 202 with an outer surface 204. An annular engagement ridge 220, which can be orthogonal to axis X, extends radially outwardly from the outer surface 204 of the bottom grommet outer sidewall 202. A floor cover retention flange 206 radially outwardly extends from the outer surface 204 of the outer sidewall 202, and is downwardly spaced from the engagement ridge 220. The outer sidewall 202 extends upwardly from the retention flange 206 at least to a top or hinge plane 207 that is orthogonal to axis X. In the illustrated embodiments the bottom grommet outer sidewall 202 has its upper end at plane 207, but in other embodiments the outer sidewall 202 could continue upwardly beyond the hinge plane 207. In operation and in this embodiment, the outer sidewall 202 extends completely through the hole 110 in a vehicle floor cover 104, as shown in FIGS. 1 and 5-5C.

[0026] A radially inwardly extending annulus 210 is disposed in the hinge plane 207 and in the illustrated embodiment is formed to be at right angles to the axis X. The annulus 210 extends from the inner surface 302 (see FIG. 3) of the outer sidewall 202 to an annulus inner end 211. A plurality of angularly spaced-apart fingers 208 are disposed around axis X, and are joined to the inner end 211 of the annulus 210 by their respective upper ends 214. In this illustrated embodiment there are six fingers 208 but other embodiments may have more or fewer fingers 208 and the fingers 208 may differ in angular width (relative to axis X) from the width illustrated. Further, while in the illustrated embodiment the angular width of the fingers is uniform, this does not have to be the case, and some of the fingers 208 may have different angular widths than others.

[0027] Each finger 208 extends axially downwardly from its upper end 214 to a lower end 212. Each finger 208 has an inner sidewall surface 218 that is in approximate alignment with axis X and may conform to an imaginary right cylinder (not shown) around axis X. Each finger 208 flexes upon being pressed outwardly while camming past the enlarged head 112 of the retention post 102 (see FIG. 5). In this embodiment, most of this flexure will occur in the vicinity of hinge plane 207, near where the upper end 214 of the finger 208 and the inner end 211 of the annulus 210 meet.

[0028] Each finger 208 has a bead 216 which is close to the lower end 212 of the finger 208. The bead 216 extends radially inwardly from the general inner sidewall surface 218 of the finger 208. The bead 216 has an inclined surface 222 which extends axially downwardly and radially inwardly from the inner sidewall surface 218 of the finger 208 to an innermost margin 226 of the bead 216. A lower inclined surface 224 of bead 216 may extend downwardly and outwardly from the innermost margin 226 of the bead 216 to the lower end 212 of the finger 208. Inclined surfaces 222, 224 may be frustoconical as shown, or alternatively may conform to other surfaces of rotation around axis X, or be planar. The distance between the inner sidewall surface 218 and the innermost margin 226 of the bead 216 may be in the range of 1 mm to 1.75 mm, as measured along a radius which is at right angles to axis X. In the illustrated embodiment, the innermost margin 226 of the bead 216 extends radially inwardly approximately 1.25 mm from the inner sidewall surface 218. The lower and upper inclined surfaces 224, 222 are at angles relative to the axis X. The angle of upper inclined surface 222 may be in the range of 30 to 60 degrees. In some embodiments the angle of inclined surface 222 may be forty-five degrees. The angle of the terminating inclined surface 224 may be in the range of 120 to 160 degrees, and may be chosen to be 150 degrees.

[0029] The bead 216 is adapted to engage a vehicle floor cover retention post or stud 102 (See FIGS. 1 and 5-5C). The bead 216 is shaped such that it can engage vehicle floor cover retention studs 102 of varied sizes and shapes, as will be discussed in conjunction with FIGS. 5-5C. In alternative embodiments the bead 216 may have a shape other than the one illustrated.

[0030] As seen in FIG. 3, the outer sidewall surface 304 of each finger 208 is opposed to the inner sidewall surface 218 of the finger 208. Surface 304 is spaced from surface 302. The inner surface 302 of the outer sidewall 202 extends from the floor cover retention flange 206 to the annulus 210.

[0031] FIG. 4 is a section, taken substantially along a plane that includes axis X, of the bottom grommet 106 as attached to the top grommet or cap 108. The top grommet 108 has a downwardly extending sidewall 402 from which an annular rib or latch 404 extends radially inwardly. The annular rib 404 of the top grommet 108 snaps over the engagement ridge 220 of the bottom grommet 106. In this manner, the top grommet 108 is secured to the bottom grommet 106. Alternative embodiments may have other features to aid in fastening the top grommet 108 to the bottom grommet 106, such as snaps of shapes different from those shown, push-and-twist arrangements, or screw threads.

[0032] Each finger 208 must have room to flex. Therefore, the radial distance (“radial” being used herein as meaning a direction at right angles to axis X) between the innermost margin 226 of the bead 216 and the general inner sidewall surface 218 of finger 208 should be less than or equal to the radial spacing between inner surface 302 of the outer sidewall 202 and the outer sidewall surface 304 of finger 208. This spacing then will be large enough to allow the complete outer radial displacement of the bead 216 as it cams past the retention post head 112. The radial thickness of the bead 216 from innermost margin 226 to the general inner sidewall surface 218 of finger 208 can be selected from the range of 1 to 3 mm. In some embodiments, the thickness of the bead 216 may be 1.25 mm.

[0033] In the illustrated embodiment, each finger 208 has two sections: a first, radial section 406, located within hinge plane 207, and a second, downwardly extending, axial section 408. The first section 406 extends radially inwardly within hinge plane 207 until its junction with second section 408. The second section 408 downwardly depends from the inner end of first section 406. Alternatively, fingers 208 could be so formed that they depend directly downwardly from annulus 210 without any intervening radial finger section.

[0034] FIGS. 5-5C illustrate the bottom grommet 106 and top grommet 108 used in affixing a vehicle floor cover 104 to each of several differently shaped vehicle retention studs 102. As seen in FIG. 5, the retention stud 102 has an enlarged head 112 which is the uppermost part of the stud 102. The head 112 has a retention stud head wall 502 and, in the embodiment shown in FIG. 5, has a sloped transition wall 504. The head sits on top of a stem 506 which is narrower in diameter than the retention stud head wall 502.

[0035] The fingers 208 of the bottom grommet 106 engage the retention stud 102. As described above, the bead 216 of the finger 208 has an upper inclined surface 222 and a lower inclined surface 224. In the illustrated embodiment, the upper inclined surface 222 of the bead 216 is smaller than the lower inclined surface 224 of the bead 216. Alternative embodiments may have fingers 208 with beads 216 that have different shapes and upper inclined surfaces 222 and lower inclined surfaces 224 that have different lengths or angles than the bead 216 illustrated in FIGS. 5-5C. Upper inclined surfaces 222 are nonetheless large enough to offer expanded loci of contact with the surfaces of different post heads 112. The inclined surfaces 222 thus provide more adaptability of the grommet to different retention posts 102.

[0036] As shown in FIG. 5, the upper inclined surface 222 engages the transition wall 504 of the retention stud 102. In this illustrated embodiment the slope of the upper inclined surface 222 and the slope of the transition wall 504 approximately match. In alternative embodiments the slopes may be different or may exactly match. The attachment of the bottom grommet 106 to the retention stud 102 is ensured when the innermost margin 226 of the bead 216 extends inwardly such that the inner diameter of the bottom grommet 106 at that point is greater than the stem 506 diameter but less than the diameter of the retention stud head wall 502.

[0037] The slope of the lower inclined surface 224 is determined such that the bottom grommet 106 can cam over the retention post head 112, and so that a user can more easily index the bottom grommet to the post head 112. The fingers 208 flex substantially within hinge plane 207 when sliding over the retention post head 112, after which the fingers 208 elastically return to their original position or, depending on the size of the engaged retention post stem 506, remain in a semi-flexed position.

[0038] Also as seen in each of FIGS. 5-5C, the cap 108 has a downwardly depending sidewall 508 with an outer sidewall surface 510. This outer sidewall surface 510 fits within floor cover hole 110 and is the portion of the grommet 105 that bounds the hole 110.

[0039] FIG. 5 shows a retention post or stud 102 with a first profile. A top 520 of the retention post is near a bottom surface 522 of the cap 108. The retention post head wall 502 is close to the general inner sidewall surface 218 of the fingers 208. The angle of the transition wall 504 approximately matches that of inclined surface 222, and is about twice as long. The diameter of stem 506 is considerably less than the inner diameter of bottom grommet 106 as measured across the innermost bead margins 226.

[0040] FIG. 5A shows grommet 105 as affixing a vehicle floor cover 104 to a retention post 530 that has a profile that is different from retention post 102. The diameter of the enlarged head 532 of the post 530 is smaller than that of post 102. The inclined surface 222 of the bead 216 is nonetheless long enough to engage post inclined wall 534 in an interference fit. A top wall 536 of the post 530 is also not as high as the top wall 520 of retention post 102.

[0041] In FIG. 5B, a retention post 540 is seen that has a significantly thicker stem 542. The diameter of stem 542 is about the same as the bottom grommet minimum inner diameter measured across innermost bead margins 226. Grommet 105 can even accommodate posts with stems that are thicker than this, so long as there is a significant difference in the diameter of the post head and that of the post stem. The position of sloped sidewall 544 and top wall 546 are similar to those for retention post 102.

[0042] The retention post 550 seen in FIG. 5C has no inclined transition wall between its head 552 and its stem 554. Instead, the vertical wall 556 of the head 552 terminates at an abrupt corner 558. A horizontal surface 560 extends from this corner 558 to a sidewall 562 of the post stem 554. The inclined surface 222 engages with corner 558 to retain the floor cover 104 on the post 550. The inclined surface 222 is extensive enough that it can snap past lower post head corners at various positions, and still retain the grommeted floor cover on the post.

[0043] FIG. 6 illustrates a second embodiment 600 of the bottom grommet. In this embodiment, relatively small (in terms of their angular width relative to axis X) guide ribs 602 are interleaved between the fingers 208. In this embodiment there is one small guide rib 602 between each pair of adjacent fingers 208 but alternative embodiments may have guide ribs 602 in fewer spaces and the guide ribs 602 may have widths and heights different from those shown. Specifically alternative embodiments may have three guide ribs 602 interleaved between a subset of the fingers 208. The guide ribs 602 are elongate and aligned with axis X, and are attached along their outer axial ends to the inner surface 302 of the outer sidewall 202. The general inner sidewall surfaces 218 of the fingers 208 each conform to an imaginary cylinder, which is slightly larger than the diameter of the largest post head 112 that the bottom grommet 106 is designed to receive, as shown in FIG. 7. The guide or support ribs 602 extend radially inwardly to stop at this same imaginary cylinder. The guide ribs 602 are not designed to flex, and they therefore are more resistant to the lateral displacement of the floor cover 104 (and of the bottom grommet 106 installed therein) relative to the retention post head 112.

[0044] A third embodiment 800 of a bottom grommet is illustrated in FIG. 8. As shown, the bottom grommet 800 has small guide ribs 802 and small cross ribs 804. Each cross rib 804 extends from the inner surface 302 of the outer sidewall 202 to the outer sidewall surface 304 of the respective finger 208. An angular width of each cross rib 304 (relative to axis X) is much smaller than the angular width of the finger 208 that it supports. For example, the angular width of the cross rib 304 can be one-fourth or less of the angular width of the finger 208. Each cross rib downwardly depends from annulus 210 for a predetermined distance that may be less than the axial length of the finger 208 that it supports. The cross ribs 804 are behind each finger 208 to increase flex strength and help provide lateral support against the head of the vehicle floor cover retention stud 102. In this embodiment there is one small guide rib 802 in between each finger and one cross rib 804 behind each finger 208 but alternative embodiments may have guide ribs 802 and cross ribs 804 in fewer spaces and the guide ribs 802 and cross ribs 804 may have varied widths and heights or ones different from those shown.

[0045] In the embodiment shown in FIG. 8, the fingers 208 will flex around a post head 112 in a way that is different than the flexure of the embodiments described above. As the fingers 208 cam over the post head 112, they will have more of a tendency to radially outwardly displace or stretch as a unit and will hingedly flex less. Such hinged flexure as does occur will more be more be likely to occur along that length of the finger 208 that is not supported or braced by a cross rib 804. Otherwise, the fingers 208 will expand as a combined hoop and thus the hoop strength of the outer sidewall 202 comes more into play. Each cross rib 804 can also be made thin enough that it will bow or tangentially displace under radial force imparted by the post head, allowing more of a hinged flexure of the finger 208 that it supports.

[0046] In the embodiment shown in FIG. 9, a bottom grommet 106 and top grommet 108 are assembled to clad a hole in a floor cover 104, and snapped over the head or stud 102 of a vehicle carpet affixation device 902. The affixation device 902 has a body 924 that may be formed of nylon or another suitable polymer compound. The device 902 has a first, lower face 922 and a second, upper face 920, both planar and substantially at right angles to axis X. The body 924 is thin, relative to the entire height of the affixation device 902, and flat, and may have a circular, square, rectangular, or hexagonal marginal shape or any other shape which produces commercially acceptable results. In the illustrated embodiment the lateral margin of the device body 924 is spaced from axis X by a radius which is many times that of the radius of head wall 908 or stem 914.

[0047] Many projections 904 downwardly extend from the first face 922 in parallel with the axis X. In this embodiment, the projections 904 are arranged in linear rows and have a triangular base and are pyramidal in shape. The projections 904 in the illustrated embodiment are spikes. Other embodiments may have projections that are different shapes and/or have bases of different shapes, such that the projections are substantially circular cones or rectangular pyramids. The projections 904 bite into the pile of the carpeting of the foot well floor which prevents the device 902, and the grommets 106, 108 and floor cover 104 attached to it, from moving.

[0048] As seen in FIG. 9, the affixation device 902 has a horizontally enlarged head 906. In this embodiment the enlarged head 906 has an upwardly concave top 912, chosen for moldability. Other embodiments may have flat tops or hollow tops. The head 906 has a head wall 908 that is circularly cylindrical and centered on axis X. The head 906 sits on top of a cylindrical stem 914 which is narrower in diameter than the head wall 908. In this embodiment, a sloped frustoconical transition surface or wall 910 proceeds upwardly and outwardly from an upper end of the outer surface of stem 914 to a lower end of the head wall 908.

[0049] The fingers 208 of the bottom grommet 106 engage the retention stud 102. As described above, the bead 216 of each finger 208 has an upper inclined surface 222 and a lower inclined surface 224. In the illustrated embodiment, the upper inclined surface 222 of the bead 216 is smaller than the lower inclined surface 224 of the bead 216. Lower inclined surface 224 may be oriented at about 150 degrees from axis X. Upper inclined surface 222 may be oriented at about 45 degrees from axis X. Alternative embodiments may have fingers 208 with beads 216 that have different shapes and upper inclined surfaces 222 and lower inclined surfaces 224 that have different lengths or angles. As illustrated in FIG. 9, the upper inclined surface 222 engages with the affixation device head 906.

[0050] As shown in FIG. 9, the upper inclined surface 222 engages the transition wall 910 of the affixation device 902. In this illustrated embodiment the slope of the upper inclined surface 222 and the slope of the transition wall 910 at least approximately match. In alternative embodiments the slopes may be different. The attachment of the bottom grommet 106 to the retention stud 102 is ensured when the innermost margin 226 of the bead 216 extends inwardly such that the inner diameter of the bottom grommet 106 at that point is greater than the stem 914 diameter but less than the diameter of the retention stud head wall 908.

[0051] The slope of the lower inclined surface 224 is determined such that the bottom grommet 106 can cam over the retention post head 906, and so that a user can more easily index the bottom grommet to the post head 906. The fingers 208 flex substantially at horizontal hinge plane 207 when sliding over the retention post head 112, after which the fingers 208 elastically return to their original position or, depending on the size of the engaged retention post stem 914, remain in a semi-flexed position.

[0052] In summary, embodiments of a vehicle floor cover grommet have been shown and described which can accommodate each of a variety of different vehicle foot well retention posts.

[0053] While illustrated embodiments of the present invention have been described and illustrated in the appended drawings, the present invention is not limited thereto but only by the scope and spirit of the appended claims.