Patent Application
20070107174
The present invention relates to methods and apparatus for fastening panels together, such as for securing a door trim panel to a door module of a vehicle.
Door trim panels are employed as interior components on automotive vehicles. One of the purposes of such interior trim panels is to present an aesthetically pleasing appearance. Door trim panels are typically mounted to structural support members on the door module. For example, door trim panels are mounted to an inner door sheet metal panel or to a door module (or frame) which replaces the traditional inner door sheet metal of the automotive vehicle.
There exist a variety of conventional fasteners for attaching panels to support members in the automotive industry. A common problem with assembling such panels has been that the fasteners are difficult to align with mating fasteners in the sheet metal of the frame. As a result, misaligned fasteners sometimes result in a mallet being employed to attach the door panel to the frame, often resulting in the fracture the fastener. Additionally, poor fastener design will subject the fasteners to overstressing during assembly or use (i.e., shutting door) and may cause the fastener to break or fatigue or otherwise result in a loss in retention strength for holding the door trim panel in place. As a result, some conventional door trim panels frequently become loose.
Many conventional fasteners are of two-piece construction: the door trim panel includes a socket often referred to as a “doghouse” and the frame includes a pin (e.g., head and shaft) arrangement. The pin secures to the frame and may be snap-fit into the doghouse to secure the door trim panel to the frame. A plurality of such fasteners are usually employed to secure the door trim panel to the frame. The heads of the pins may be preassembled into the respective doghouses. Once a desired number of pins have been secured to the door trim panel via the doghouses, the panel may be secured to the frame by inserting the shaft (or shank) ends of the pins into respective bores formed through the frame. The benefit of using the doghouses to secure the pins to the door trim panel is that a blind connection may be made between the panel and frame, i.e., there is no externally visible fastener present in the door trim panel once the connection between the panel and the frame has been made.
Of significant concern in a two-piece fastener design are the degree to which the pins are easily aligned and inserted into the doghouses, and the degree to which the pins are retained in the doghouses once snapped in.
U.S. Pat. No. 6,594,870 discloses a conventional two-piece fastener for coupling a door trim panel to a frame, the entire disclosure of which is hereby incorporated by reference. A doghouse 15 includes a wall 16 and an aperture 25 therethrough, the aperture 25 having a generally circular opening with an open edge 27 for lockably receiving a grommet 40 of a pin 60. The doghouse 15 includes inclined surfaces 26 and 28 for camming the grommet 40 into the aperture 25. A pair of resilient arms 30, 32 extend from a leading edge of the wall 16 toward the aperture 25. The arms 30, 32 have tips 31, 33, respectively, which engage and lock the grommet 40 in place once inserted into the keyed aperture 25. The tips 31, 33 of arms 30, 32, respectively, have inclined camming surfaces 34 to assist in deflecting the arms 30, 32 as the grommet 40 is snap-locked into the aperture 25. The socket 15 may be integrally molded of a polymeric material and integrally formed with the door panel 10 or otherwise suitably attached thereto by ultrasonic welding, adhesive bonding, or the like.
Among the problems that the inventors herein have discovered with the doghouse design employed in U.S. Pat. No. 6,594,870 and by others is that an overall depth dimension of the doghouse must be relatively large to accommodate the resilient arm(s), e.g. the arms 30, 32 of U.S. Pat. No. 6,594,870 that extend from the leading edge of the wall 16 toward the aperture 25.
Another conventional two-piece fastener includes bumps or ridges to achieve the snap-fit connection of the pin and doghouse as opposed to using resilient arms as in U.S. Pat. No. 6,594,870. The bumps are disposed around the slot/aperture to retain the grommet in the aperture. While the use of bumps may reduce the depth dimension of the doghouse somewhat, it does not reduce such dimension as much as would be desirable and it increases the likelihood that the pin will disengage from the doghouse.
As a result of all the difficulties with existing fasteners for attaching, e.g., vehicle trim panels to vehicle sheet metal, and particularly door panels to the sheet metal structure of a door, warranty claims for loose panels and broken fasteners are one of the major concerns in the automotive interior trim field.
Thus, there are needs in the art for a new approach to securing a panel to a frame, preferably which reduces the depth dimension of the doghouse and/or improves the ability of the pin to remain locked in the doghouse.
In accordance with one or more embodiments of the present invention, a fastener system for attaching, e.g., an interior door trim panel to a metal frame of the door (or door module), may include a plurality of fasteners (or pins) and doghouses. Some or all of the fasteners may each include a shaft with a head sized and shaped to snap-fit into the doghouse. The shaft of the fastener may connect to the metal door frame by resistance or interference fit. The doghouses are preferably integrally molded with the interior door panel. The doghouses may each include an insertion area that slideably receives a head of one of the fasteners, such that it is clipped in. The insertion area preferably includes a keyhole-shaped aperture for receiving the head and a clip that is located under the aperture. More specifically, the clip preferably includes a pivotable arm that extends from a first end at a rear of the aperture to a second end terminating toward (and/or forward) of the aperture. The clip may include an angle snap at the second end to engage the head of the fastener. The doghouse may include one or more guides (or ribs) below the aperture to prevent the head from moving downward through the clip (e.g., longitudinally with respect to the pin).
Among the advantages of the embodiments of the invention includes the ability to reduce the depth dimension of the doghouse as compared with some conventional designs without sacrificing retention of the pin in the doghouse. In particular, the doghouse depth may be reduced at least in part because the clip extends from the first end at a rear of the aperture to the second end terminating toward (and/or forward) of the aperture. Thus, additional structural footprint need not be employed to accommodate a clip extending from the opposite direction.
The door panel can be assembled to the door module in two ways: (1) with the shafts of the fasteners already inserted in the door module and the heads of the fasteners elevated somewhat, the door panel is slid into position such that the doghouses slide over the heads and capture them; or (2) with the heads of the fasteners already slid into the doghouses, the door panel is pressed against the door module such that the shafts of the fasteners are inserted into respective bores the door module.
In accordance with one or more aspects of the present invention, an apparatus for coupling a panel to a frame includes: a support plate coupled to the panel; an engagement plate extending transversely from the support plate and having an aperture extending therethrough; and a clip having a pivotable arm extending from the support plate at a first end, and at least partially under the aperture to a second end. The plate, aperture and clip are preferably sized and shaped to slideably receive a head and shaft of a mating fastener, coupled to the frame, toward the support plate such that the second end of the pivotable arm engages the head when the shaft is fully received in the aperture. It is noted that in some embodiments, the support plate may be an integral part of the panel.
The clip preferably includes an angle snap at the second end thereof, the angle snap being operable to retain the head of the mating fastener after it is received in the aperture. For example, the angle snap may include a sloping surface from the second end of the clip toward the engagement plate for slideably engaging the head of the mating fastener and pivoting the clip away from the aperture during insertion thereof toward the support plate. Alternatively or in addition, the angle snap may include a hook element adjacent to the sloping surface, the hook element being operable to retain the mating fastener within the aperture when the head thereof slides off of the sloping surface toward the support plate and the clip pivots back toward the engagement plate. For example, the hook element may include a surface extending transversely from the pivotable arm of the clip substantially toward the engagement plate, the surface of the hook element engaging the head of the mating fastener to retain same in the aperture.
The engagement plate preferably includes a slot extending from a leading edge thereof to the aperture, the slot including inwardly directed side surfaces operable to guide the head and shaft of the mating fastener toward the support plate and into the aperture. The second end of the clip may be positioned proximate to the slot. The second end of the clip may extend short of, at, or past the leading edge of the engagement plate.
The apparatus may further include at least one guide rib having at least a portion of a surface sloping toward the engagement plate to guide the head and shaft of the mating fastener into the aperture. For example, the at least one guide rib may include a respective guide rib disposed on opposite sides of the aperture, each guide rib having at least a portion of a surface sloping toward the engagement plate to guide the head and shaft of the mating fastener into the aperture. The guide rib(s) prevent the head from moving downward through the aperture and placing excessive pressure the clip (which might damage the clip and other structures).
In accordance with one or more aspects of the present invention, a method for coupling a panel to a frame includes: coupling an engagement plate substantially parallel to the panel, the engagement plate having an aperture extending therethrough which is oriented transversely to the panel, and a slot extending from a leading edge of the engagement plate to the aperture, the slot including inwardly directed side surfaces operable to guide a head and shaft of a mating fastener into the aperture; providing a clip having a pivotable arm extending from a first end at least partially under the aperture and at least toward the leading edge of the engagement plate to a second end; slideably receiving the head and shaft of the mating fastener into the aperture; and preventing the head and shaft of the mating fastener from sliding out of the aperture through the slot using the clip in tension.
Other aspects, features, advantages, etc. will become apparent to one skilled in the art when the description of the preferred embodiments of the invention herein is taken in conjunction with the accompanying drawings.
For the purposes of illustrating the various aspects of the invention, there are shown in the drawings forms that are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.
With reference to the drawings, wherein like numerals indicate like elements, there is shown in
The fastening system 100 includes a doghouse 106 and a mating fastener (or pin) 108. The doghouse 106 includes a support plate 110 extending transversely (e.g., perpendicularly) from the panel 102, and an engagement plate 112 extending transversely from the support plate 110. Although not required, it is preferred that the engagement plate 112 extends substantially perpendicularly from the support plate 110 and substantially parallel with the panel 102. The engagement plate 112 preferably includes an aperture 114 extending therethrough, preferably with its axis oriented transversely with respect to the panel 102. The engagement plate 112 also preferably includes a slot 116 extending from a leading edge 118 of the engagement plate 112 to the aperture 114. In this regard, although not required the aperture 114 and slot 116 may assume a keyhole shape. Preferably, the slot 116 includes inwardly directed side surfaces 120, 122 that taper from the leading edge 118 toward the aperture 114.
Preferably, the doghouse 106 is integrally formed of injection moldable plastic material so as to be of a one-piece construction. Most preferably, the doghouse 106 is integrally molded with the panel 102 using suitable polymeric materials.
Although the pin 108 may take on any number of features and characteristics known to those skilled in the art, or apparent to those skilled in the art from the description herein. By way of example, the pin 108 may include a shaft 124 that extends through a bore 126 in the door module 104, e.g., by way of fins 128. At a distal end of the shaft 124, the pin 108 preferably includes a head 130 that defines a mating mechanism for the doghouse 106. For example, the head 130 may include a grommet formed by first and second disks 132, 134 separated by a portion of the shaft 124.
Preferably, the engagement plate 112, slot 116, and aperture 114 are sized and shaped to slideably receive the head 130 of the mating fastener 108 and retain same therein in order to securely couple the panel 102 to the door module 104.
In accordance with one or more embodiments of the invention, the fastening system 100 may include further features to accomplish the snap-fit connection of the mating fastener 108 in the doghouse 106. In this regard, reference will now be made to
By way of example, the clip 140 may include an angle snap at the second end 146 thereof, where the angle snap is operable to retain the head 130 of the mating fastener 108 after it is received in the aperture 114. More particularly, the angle snap may include a sloping surface 148 from the second end 146 of the clip 140 toward the engagement plate 112. The sloping surface 148 is operable to slideably engage the head 108 (e.g., the disk 134 thereof) of the mating fastener 108 and to cause the arm 142 to pivot about the first end 144 and to cause the angle snap of the clip 140 to move away from the engagement plate 112 as the head 130 slides through the slot 116 into the aperture 114.
As best seen in
The clip 140 preferably includes a hook element 160 adjacent to the sloping surface 148. The hook element 160 is preferably operable to retain the head 130 of the mating fastener 108 within the aperture 114 when the head 130 slides off the sloping surface 148 toward the support plate 110 and the clip 140 pivots back toward the engagement plate 112. In this regard, the hook element 160 preferably includes a surface 162 extending transversely from an upper surface 164 of the pivotable arm 142 and toward the engagement plate 112. Thus, the surfaces 162, 164 of the clip 140 preferably retain the head 130 of the mating fastener 108 (e.g., the disk 134 thereof) from moving downward (vis-à-vis surface 164) or out through the slot 116 (vis-à-vis surface 162). Indeed, once the clip 140 pivots back into its resting position, the disk 134 is preferably trapped against a lower surface of the engagement plate 112 on the one hand, and by the surfaces 162, 164 on the other hand.
Preferably, the second end 146 of the clip 140 is positioned proximate to the slot 116. Indeed, those skilled in the art will appreciate that the second end 146 of the clip 140 may terminate short of the leading edge 118 of the engagement plate 112, at the leading edge 118, or past the leading edge 118.
As best seen in
The panel 102 can be assembled to the door module 104 in a number of ways, such as: (1) with the shafts 124 of the fasteners 108 already inserted in the door module 104 and the heads 130 of the fasteners 108 elevated somewhat, the door panel 102 is slid into position such that the doghouses 106 slide over the heads 130 and capture them; or (2) with the heads 130 of the fasteners 108 already slid into the doghouses 106, the panel 102 is pressed against the door module 104 such that the shafts 124 of the fasteners 108 are inserted into respective bores 126 the door module 104.
The doghouse 106 may also include at least one guide rib 170 having at least a portion 172 thereof sloping toward the engagement plate 112 to guide the head 130 of the mating fastener 108 into the aperture 114. In a preferred embodiment, a first guide rib 170 and a second guide rib 174 are disposed on opposite sides of the aperture 114, where each guide rib includes a surface that at least partially slopes toward the engagement plate 112. Advantageously, the guide ribs 170, 174 assist in guiding the head 130 into the doghouse 106 as well as preventing the mating fastener 108 from moving downward (e.g., longitudinally with respect to the shaft 124 direction) into the doghouse 106 and potentially damaging same.
Advantageously, the clip 140 permits serviceability of the panel 102, e.g., the panel 102 may be disconnected from the frame 104 numerous times without damaging the doghouse 106 or the fastener 108. Another advantage of the design of the clip 140 is the ability to reduce the depth dimension of the doghouse 106 as compared with some conventional designs without sacrificing retention of the mating fastener 108 in the doghouse 106. Further advantages include improved guiding of the head 108 into the doghouse, for example, resulting from employing one or more of the features of the clip 140, the slot 116 and the rib(s) 170, 174.
Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.
