The present invention relates to a tether component and method of manufacturing the tether component, which is implemented in a liftgate for an automobile.
One of the current trends in the automobile industry is to lower vehicle weight to help achieve better fuel economy, thus helping to meet fuel economy standards and to offset the higher fuel prices. Another trend is that there is a broader range of vehicle models, which in turn reduces the volume of vehicles produced on a per model basis. Liftgates are traditionally made from stamped steel panels that are heavy and have a high tooling cost and are susceptible to corrosion. Sheet Molding Compound (SMC) is an alternative to steel for the inner and outer panels of the liftgate. Using SMC has several manufacturing concerns related to the material and process. Steel and SMC liftgates have a mass penalty over thermoplastics. There are also styling restrictions with traditional sheet metal and SMC components.
In certain applications where liftgates are made from composite materials. Tethers made from steel are used to strengthen the liftgate and help maintain the integrity of the liftgate upon impact. The use of steel tethers can be difficult to attach and increase the assembly complicity. It is therefore desirable to design liftgates that have tether systems that are easier to assemble, require less attachment points and still provide the desired level of strength to the liftgate while allowing for maintaining the integrity of the liftgate upon impact.
Over molded ends are sometimes used in flexible tether arrangements such as with belt materials or wires to help the fibers of the tether in such a way that the integrity and strength of the individual fibers is preserved. However, overmolding processes are costly and time consuming because of added tooling and labor costs during manufacture. It is further a desirable to provide a tether system that is flexible and is connected to the liftgate panel through apertures without the necessity of overmolding. It is also desirable to provide a tether system that has failure modes, such as a controlled release failure mode.
It is desirable to develop lower cost tethers that would reduce or eliminate overmolding to the tether belt material but still provide the desired performance. Therefore, it is a goal to provide a lightweight, consistent failure mode tether using more readily available materials to keep costs down.
The present invention relates to a multilayered tether link for a vehicle tether implemented in a molded vehicle liftgate. The tether has two ends and connects to a vehicle part using a folded wedge section and a folded section of the tether. There is a folded wedge section formed by a tether belt material being sinuously being folded about at least one wedge portion. The tether belt material and the at least one wedge portion are sewn together with at least one stich to form a layered construction. The layered construction has a hole is formed through the layered construction for attachment to a vehicle part.
The multilayered tether link further includes a folded section having a plurality of layers of sinuously folded tether belt material folded adjacently to form a plurality of layers. The folded section further includes at least one stich connecting the plurality of layers together. Also provided is a hole formed through the center of the folded section for attachment to a vehicle part. The vehicle part can be any component of the liftgate and can include the liftgate inner panel, wiper motor housing, support brackets, outer panel of the liftgate, latch mounting bracket or latch actuator housing.
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.
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
The following description of the preferred embodiments are merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
Referring now to
The tether 12 includes two ends each for connecting the tether 12 to a vehicle part, which in the current embodiment of the invention is a wiper motor housing 128 in the wiper motor housing recess 118. The tether 12 is positioned through each of the friendly holes 126 of each of the plurality brackets 120, 122, 124.
While the present embodiment of the invention depicts the tether 12 as being routed through various bracket members, it is within the scope of this invention for the friendly holes 126, to be formed with the structural inner panel 100, thereby eliminating the need for different brackets 120, 122, 124. Additionally, the placement of the brackets 120, 122, 124 are located in predetermined tether reinforcement zones, which are areas on the structural inner panel 100 that are determined to be structurally stronger areas of the liftgate than the portions of the inner panel not located in the tether reinforcement zones. The tether reinforcement zones are best for placement of connections for the tether 12. The structural reinforcement zones allow for the tether 12 to span areas of the composite liftgates that are structurally weaker and will benefit from having the tether 12 passing across the weaker area to be connected to the tether reinforcement zones of the liftgate. The location of the tether reinforcement zones can vary depending upon the design of the liftgate. Factors such as shape, material thickness, material makeup and the dimensions of the liftgate can have an effect on the location of the tether reinforcement zone. Routing the tether 12 between each tether reinforcement zones causes the tether 12 to cross weaker areas of the liftgate to create a type of safety net that will hold the structural inner panel together in the event of breaking of the structural inner panel in the weaker areas between the tether reinforcement zones.
The tether 12 has a specialized construction forming part of a multilayered tether link that is shown in
As shown the tether 12 has an end 14a that is folded about wedge portion 24a, while end 14b is folded about wedge portion 24b. The wedge portions 24a, 24b are used in the present embodiment of the invention, but they are optional and in some embodiments of the invention they are not used due to the requirements of a particular design. For example,
Referring back to
The multilayered tether link 10 further includes a folded section 20 having a plurality of layers of sinuously folded tether belt material folded adjacently to form a layered construction 33. In a preferred embodiment the belt material 14 of the folded section is wound in sinusoidally upon itself to provide an āsā type arrangement. The folded section further includes at least one stich connecting the plurality of layers together. Also provided is a hole 34 formed through the center of the layered construction 33 for attachment to the vehicle part 16. The hole 34 is formed ultrasonically using heat knife that prevents fraying. The vehicle part 16 can be any component of the liftgate and can include the liftgate inner panel, wiper motor housing, support brackets, outer panel of the liftgate, latch mounting bracket or latch actuator housing.
The vehicle part 16 can be any component of a liftgate for a vehicle and can include the liftgate inner panel, wiper motor housing, support brackets, outer panel of the liftgate, latch mounting bracket or latch actuator housing. Regarding the tether belt material 22, Suitable tether belt materials are selected from the group of woven materials including polyester, nylon, aramid fibers including para-phenylene-terephtalamide, each alone or in combination.
The multilayered tether link 10 is connected to the vehicle part 16 it will provide controlled release of the tether 12 upon experiencing force of an impact of accident. The controlled release of the tether 12 is provided by the combination of the folding of the tether belt material 22 in the area of the folded wedge section 18 and the at least one stich forming the layered construction 26 of the folded wedge section 18, and the folded section 20 and the at least one stich forming the layered construction 33. Referring now to
The multilayered tether link 10, 200 shown in
Referring now to
The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the essence 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.
Filing Document | Filing Date | Country | Kind |
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PCT/US22/13071 | 1/20/2022 | WO |
Number | Date | Country | |
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63139326 | Jan 2021 | US |