(712344PCT)

LIFTGATE REINFORCEMENT MECHANICAL ATTACHMENT

ARRANGEMENT

FIELD OF THE INVENTION The present invention relates to a reinforcement attachment arrangement for a thermoplastic liftgate.

BACKGROUND OF THE INVENTION

Many vehicles, in particular SUV's have what is commonly referred to as a rear liftgate, which is essentially a door that seals the back or rear portion of the vehicle passenger compartment. Production of these liftgates can be expensive and time consuming because there are many components that need to be assembled together.

Recently the automotive field has migrated toward producing the rear liftgate from thermoplastic materials. Typically, this involves producing an inner panel made of thermoplastic, attaching several reinforcement pieces at strategic locations on the inner panel, and then attaching an exterior panel or panels, which form the outside surface of the liftgate panel and vehicle.

Connection of the reinforcement panels to the inner panel during assembly has traditionally been done using several fasteners. The process involves straight loading the reinforcement and holding it with multiple fasteners, which increases production cost and production time. It is desirable to reduce the number of fasteners required for connecting a reinforcement to the inner Attorney Docket No. DEC-00448-PCA

(712344PCT) panel, which will save production time as well as costs. Attempts to eliminate the fasteners have been made, which include overmolding the reinforcement to the liftgate inner panel or using adhesives or welding to connect the reinforcement panel to the liftgate inner panel. These approaches increase the production time and also require additional equipment, thereby increasing manufacturing costs in the short term. It is therefore desirable to develop methods that will reduce production time, while also keeping costs in control. It is also an object of the present invention to develop an assembly arrangement that will reduce the number of fasteners.

SUMMARY OF THE INVENTION

A reinforcement attachment arrangement for a thermoplastic liftgate having a liftgate inner panel with an outer surface area defining a plurality of reinforcement areas. Each reinforcement area has at least one receiving portion and at least one connection member extending from the outer surface area of the liftgate inner panel. Connected to each reinforcement area is a reinforcement connected to each respective one of the plurality of reinforcement areas of the inner panel. Each reinforcement includes at least one engagement tab for engaging the at least one receiving portion formed on the respective reinforcement area. The reinforcement includes apertures that align with the connection member formed on the outside surface of the liftgate inner panel, to hold the reinforcement onto the outer surface of the liftgate inner panel. The Attorney Docket No. DEC-00448-PCA

(712344PCT) arrangement further includes a liftgate exterior panel connected to the liftgate inner panel and covering the reinforcement areas and each reinforcement.

Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

Fig. 1 A is a rear perspective view of a thermoplastic liftgate.

Fig. 1B is a rear perspective view of a liftgate inner panel with the reinforcements attached. Fig. 2 is a side cross-sectional elevational view of a portion of a thermoplastic liftgate.

Fig. 3 is a side cross-sectional elevational view of a portion of the thermoplastic liftgate.

Fig. 4 is a side cross-sectional elevational view of a portion of the thermoplastic liftgate.

Fig. 5 is a side cross-sectional elevational view of a portion of the thermoplastic liftgate. Attorney Docket No. DEC-00448-PCA

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Fig. 6 is a side cross-sectional elevational view of a portion of the thermoplastic liftgate.

Fig. 7 is a side cross-sectional elevational view of an alternate reinforcement arrangement of the thermoplastic liftgate. Fig. 8A is an enlarged top perspective view of a connection member in a first position.

Fig. 8B is an enlarged top perspective view of the connection member of Fig. 8A in a second position.

Fig. 9 is a side cross-sectional plan view of a second alternate connection member of the thermoplastic liftgate.

Fig. 10A is a side cross-sectional elevational view of an alternate reinforcement arrangement.

Fig. 10B is an enlarged cross-sectional elevational view of the reinforcement arrangement of Fig. 10A. Fig. 11A is a side cross-sectional elevational view of an alternate reinforcement arrangement.

Fig. 11 B is an enlarged cross-sectional elevational view of the reinforcement arrangement of Fig. 11 A.

Fig. 12A is a side cross-sectional elevational view of an alternate reinforcement arrangement.

Fig. 12B is an enlarged cross-sectional elevational view of the reinforcement arrangement of Fig. 12A. Attorney Docket No. DEC-00448-PCA

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Fig. 13A is a side cross-sectional elevational view of an alternate reinforcement arrangement.

Fig. 13B is an enlarged cross-sectional elevational view of the reinforcement arrangement of Fig. 13A. Fig. 14 is an enlarged cross-sectional top view of an alternate fixing proposal for a reinforcement arrangement.

Fig. 15A is a side cross-sectional elevational view of an alternate reinforcement arrangement.

Fig. 15B is an enlarged cross-sectional elevational view of the reinforcement arrangement of Fig. 15A.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

Referring now to Figs. 1A, 1B to 6 a reinforcement attachment arrangement 10 for a thermoplastic lift gate 12 for connection to a vehicle is shown. The thermoplastic liftgate 12 includes a liftgate inner panel 14 having an outer surface area 16. Fig. 1A shows a thermoplastic liftgate 12 having an outer panel 11 connected to and covering the inner panel 14 shown in Fig. 1A. The thermoplastic liftgate 12 has several components attached, including hinges and actuators with ball stud attachments that connect the thermoplastic liftgate 12 to the vehicle, as well as latch and accessory reinforcements. In the present Attorney Docket No. DEC-00448-PCA

(712344PCT) embodiment of the invention, many of these components are attached at a location where a reinforcement 18a, 18b, 20a, 20b, 22 has been connected to the liftgate inner panel 14. Each reinforcement 18a, 18b, 20a, 20b, 22 is connected to a reinforcement area 24a, 24b, 24c, 24d, 24e formed on the outer surface of the liftgate inner panel 14. As shown in Fig. 1B reinforcement area 24a is a left side hinge reinforcement area and reinforcement area 24b is a right side hinge reinforcement area. While two reinforcement areas for hinges are shown it is within the scope of this invention for there to be more than two or just a single hinge reinforcement area. Fig. 1A also shows reinforcement area 24d which is a left side ball stud reinforcement area and reinforcement area 24c which is a right side ball stud reinforcement area. The ball stud reinforcement area is where one end of a pneumatic shock or other devices, such as an actuator, is attached to a ball stud for assisting in the opening and closing of the lift gate when attached to the vehicle. While two ball stud reinforcement areas are shown it is within the scope of this invention for there to just be a single ball stud reinforcement area, or for there to be more than two balls that reinforcement areas formed on the outer surface of the liftgate inner panel 14.

In Fig. 1A reinforcement area 24e is a latch reinforcement area located in the vicinity of the liftgate inner panel 14. While two latch reinforced areas are shown, it is within the scope of this invention for there to be a greater or lesser number of latch reinforcement areas, depending upon the needs of a particular application. Attorney Docket No. DEC-00448-PCA

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Each reinforcement area 24a, 24b, 24c, 24d, 24e has a respective reinforcement 18a, 18b, 20a, 20b, 22 connected. The reinforcement 18a, 18b, 20a, 20b, 22 can be a piece of metal, or stiff polymer that is connected to the liftgate inner panel 14 and will provide additional rigidity in support for connecting the other structures mentioned above. The connection between each reinforcement 18a, 18b, 20a, 20b, 22 and its respective reinforcement area 24a, 24b, 24c, 24d, 24e is provided by features located on both the reinforcement area 24a, 24b, 24c, 24d, 24e and the reinforcement 18a, 18b, 20a, 20b, 22. Generally each reinforcement 18a, 18b, 20a, 20b, 22 has an engagement tab 26a, 26b, 26c, 26d, 26e that slides or pivots beneath a receiving portion 28a,

28b, 28c, 28d, 28e formed in the reinforcement area 24a, 24b, 24c, 24d, 24e.

The receiving portion 28a, 28b, 28c, 28d, 28e can take several forms and can be a bridge in the liftgate inner panel 14 formed between two surfaces, a flange or undercut formed on the surface of the liftgate inner panel 14 or an aperture formed in the liftgate inner panel 14. While five receiving portions 28a, 28b, 28c, 28d, 28e are depicted, it is within the scope of this invention for the respective reinforcement to have multiple engagement tabs that engage a respective receiving portion. Depending on the size of the reinforcement, it is within the scope of this invention for there to be multiple receiving portions on a single reinforcement, each configured to connect to one of multiple receiving portions on the liftgate inner panel.

When the reinforcement 18a, 18b, 20a, 20b, 22 slides into position, there is one or more apertures 30a, 30b, 30c, 30d, 30e, 30f formed on the Attorney Docket No. DEC-00448-PCA

(712344PCT) reinforcement 18a, 18b, 20a, 20b, 22 that aligns with a connection member 32a, 32d, 32e formed on the outside surface of the liftgate inner panel 14 in the region of the reinforcement area 24a, 24b, 24c, 24d, 24e. In the present embodiment of the invention shown in the figures the connection member is a fastener boss that is configured to threadably receive a fastener 34a, 34d, 34e that is positioned through the aperture of the reinforcement member, thereby holding the reinforcement member against the fastener boss to lock the reinforcement into place at the reinforcement area. Depending on the size of the reinforcement, it is within the scope of this invention for a given for there to be multiple apertures that allow for connection of the reinforcement to one of multiple connection members on the liftgate inner panel.

The present embodiment of the invention reduces the number of fasteners needed for connecting the reinforcement since the use of the engagement tab 26a, 26b, 26c, 26d, 26e sliding into contact with the respective receiving portion 28a, 28b, 28c, 28d, 28e eliminates several fasteners that would normally be used to secure the reinforcement in the area of the receiving portion 28a, 28b, 28c, 28d, 28e.

Once all of the reinforcements have been connected to the liftgate inner panel 14, the thermoplastic liftgate further includes attaching a liftgate exterior panel that covers the liftgate inner panel 14 and reinforcements. The liftgate exterior panel 11 is attached and becomes a portion of the exterior surface of the vehicle. Attorney Docket No. DEC-00448-PCA

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Figs. 7-9 depict alternate embodiments of the invention which eliminate the use of fasteners altogether. In Figs. 7, 8A, 8B there is shown a reinforcement member 118 and liftgate inner panel 114 that could be used in place of the liftgate inner panel 14 and reinforcement 18a, 18b, 20a, 20b, 22 shown in Figs. 1-6. The liftgate inner panel 114 has connection member that is a key post 132 with a round head 133 and stem 135 that aligns with a keyhole 137 on the reinforcement 118 so that when an engagement tab 126 of the reinforcement 118 slides under a receiving portion 128 of a reinforcement area 124, the key post 132 extends through a wider portion of the keyhole 137 and then slides to a narrow portion 139, thereby locking the reinforcement 118 in place against the lift gate inner panel 114.

Fig. 9 depicts another alternate embodiment where the connection member is several push posts 232a, 232b, 232c, 232d that are configured to align with and pass through several apertures 230a, 230b, 230c, 230d formed on a reinforcement 218 once an engagement tab 226 has been slid under a receiving portion 228 of a reinforcement area 224. In both alternate embodiments of the invention, it is within the scope of the invention to use a greater or lesser number of connection members depending on the needs of a particular application. Figs. 10A and 10B show a reinforcement arrangement 300 according to an alternate embodiment of the invention. The reinforcement arrangement 300 includes a liftgate inner panel 302 having an outer surface 304. Formed on the outer surface 304 is a receiving portion 306 to which an engaging tab 308 of a Attorney Docket No. DEC-00448-PCA

(712344PCT) reinforcement 310 engages. The reinforcement 310 is connected to the liftgate inner panel 302 using a fastener 312 connected to a boss 314 formed on the liftgate inner panel 302. While a fastener 312 is used it is within the scope of this invention for a different type of connection to be used, such as adhesives, welds and mechanical push connections. The reinforcement 310 has an engagement tab 308 of the reinforcement 310 has a neck 316 that forms a bend in the reinforcement 310 that terminates at an engagement end 318 that bends generally perpendicular to the surface of the neck 316. The neck 316 bends in a manner that creates a space between the neck 316 and an aperture wall 317 of the liftgate inner panel 302. The receiving portion 306 of the liftgate inner panel 302 has an aperture 320 that the engagement end 318 slides into to connect the reinforcement 310 to the liftgate inner panel 302. This arrangement prevents the reinforcement 310 from pulling out of the aperture 320 along arrow A and prevents up and down movement along arrow B. The reinforcement arrangement 300 shown in Figs. 10A and 10B can be used in place or in combination with any reinforcement area 24a-e and inner panel 14 shown in the earlier figures.

Figs. 11A and 11 B show a reinforcement arrangement 400 according to an alternate embodiment of the invention. The reinforcement arrangement 400 includes a liftgate inner panel 402 having an outer surface 404. Formed on the outer surface 404 is a receiving portion 406 to which an engaging tab 408 of a reinforcement 410 engages. The reinforcement 410 is connected to the liftgate inner panel 402 using a fastener 412 connected to a boss 414 formed on the Attorney Docket No. DEC-00448-PCA

(712344PCT) liftgate inner panel 402. While a fastener 412 is used it is within the scope of this invention for a different type of connection to be used, such as adhesives, welds and mechanical push connections. The reinforcement 410 has an engagement tab 408 of the reinforcement 410 has a neck 416 that forms a bend in the reinforcement 410 that terminates at an engagement end 418 that bends generally perpendicular to the surface of the neck 416. The receiving portion 406 of the liftgate inner panel 402 has an aperture 420 that the engagement end 418 slides into to connect the reinforcement 410 to the liftgate inner panel 402. The neck 416 in this embodiment has bends to rest against an aperture wall 417 when the engagement end 418 is positioned in the aperture 420. This prevents the reinforcement 410 from pulling out of the aperture 420 but prevents the reinforcement 410 from being further pushed into the aperture 420 along arrow C. Additionally, this arrangement prevents movement along arrow B’. The reinforcement arrangement 400 shown in Figs. 10A and 10B can be used in place or in combination with any reinforcement area 24a-e and inner panel 14 shown in the earlier figures.

Figs. 12A and 12B show a reinforcement arrangement 500 according to an alternate embodiment of the invention. The reinforcement arrangement 500 includes a liftgate inner panel 502 having an outer surface 504. Formed on the outer surface 504 is a receiving portion 506 to which an engaging tab 508 of a reinforcement 510 engages. The reinforcement 510 is connected to the liftgate inner panel 502 using a fastener 512 connected to a boss 514 formed on the liftgate inner panel 502. While a fastener 512 is used it is within the scope of this Attorney Docket No. DEC-00448-PCA

(712344PCT) invention for a different type of connection to be used, such as adhesives, welds and mechanical push connections. The reinforcement 510 has an engagement tab 508 of the reinforcement 510 has a neck 516 that forms a bend in the reinforcement 510 away from a main surface 511 of the reinforcement 510 that terminates at an engagement end 518. The receiving portion 506 of the liftgate inner panel 502 has an aperture 520 that forms an opening or entrance to a blind hole 519 with a flexible tab 521. A portion of the main surface 511 , neck 516 and engagement end 518 slide through the aperture 510 into the blind hole 519 and frictionally engages the flexible tab 512 that holds the reinforcement 510 in place on the liftgate inner panel 502. In this embodiment the neck 516 has a bend that provides some flexibility to the engagement tab 508, which helps to facilitate the frictional engagement of the engagement tab 508 with the flexible tab 521 when the engagement tab 508 is inserted into the blind hole 519. This prevents the reinforcement 510 from pulling out of the aperture 520 but prevents the reinforcement 510 from being pulled out of the aperture 520 along arrow D, while the blind hold 519 prevents the reinforcement 510 from being pushed into the aperture 520 along arrow E. The reinforcement arrangement 500 shown in can be used in place or in combination with any reinforcement area 24a-e and inner panel 14 shown in the earlier figures. Figs. 13A and 13B show a reinforcement arrangement 600 according to an alternate embodiment of the invention. The reinforcement arrangement 600 includes a liftgate inner panel 602 having an outer surface 604. Formed on the outer surface 604 is a receiving portion 606 to which an engaging tab 608 of a Attorney Docket No. DEC-00448-PCA

(712344PCT) reinforcement 610 engages. The reinforcement 610 is connected to the liftgate inner panel 602 using a fastener 612 connected to a boss 614 formed on the liftgate inner panel 602. While a fastener 612 is used it is within the scope of this invention for a different type of connection to be used, such as adhesives, welds and mechanical push connections. The reinforcement 610 has an engagement tab 608 of the reinforcement 610 has a neck 616 that forms a bend in the reinforcement 610 away from a main surface 611 of the reinforcement 610 that terminates at an end 618. The receiving portion 606 of the liftgate inner panel 602 has an aperture 620 formed in the liftgate inner panel 602 that includes a tab 621. A portion of the main surface 611 , neck 616 and end 618 slide through the aperture 610 and frictionally engage the tab 612 that holds the reinforcement 610 in place. In this embodiment the neck 616 has a bend that provides some flexibility to the engagement tab 608, which helps to facilitate the frictional engagement of the engagement tab 608 with the tab 621 when the engagement tab 608 is inserted into the aperture 620. This prevents the reinforcement 510 from pulling out of the aperture 620 and prevents the reinforcement from moving away from the liftgate inner panel 602 along arrow F. The reinforcement arrangement 600 can be used in place or in combination with any reinforcement area 24a-e and inner panel 14 shown in the earlier figures. Fig. 14 is another embodiment of the invention that provides an alternate fixing proposal for a reinforcement arrangement 700 that can be used in place or in combination with any reinforcement area and inner panels shown in the earlier figures. In this embodiment of the invention the liftgate inner panel 702a, 702b Attorney Docket No. DEC-00448-PCA

(712344PCT) has an aperture 704 formed therein that has slanted edges 706, 708. A reinforcement 710 has a tab 712 formed as part of an engagement tab that frictionally fits into the aperture 704 against the slanted edges 706, 708. The tab 712 has slanted edges 714, 716 that together with the slanted edges 706, 708 facilitate alignment of the tab 712 into the aperture 704.

Figs. 15a and 15b depict another embodiment of the invention that provides an alternate fixing proposal for a reinforcement arrangement 800 that can be used in place or in combination with any reinforcement area and inner panels shown in the earlier figures. In this embodiment of the invention a reinforcement 802 has an engagement tab formed thereon that has a pair of opposing tabs 806a, 806b that slide into engagement with a flange 808 formed on a liftgate inner panel 810. These opposing tabs 806a, 806b lock the reinforcement 802 in place against the liftgate inner panel 810 by positioning the tabs 806a, 806b between the flange, which prevents the reinforcement 802 from sliding past the flange 808.

The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.