Mounting clip for plastic containers

Abstract

A clip for attaching a component to a container. The clip has a generally tubular body including folds giving the clip a corrugated appearance. The clip and container are formed from similar plastic materials so that when the clip is placed in contact with a container having latent heat from formation, the exterior surface of the folds melts to the container to form a bond area. The folds also define a passageway in which the component is retained.

Description

BACKGROUND OF THE INVENTION

[0001] The present invention relates generally to fasteners for plastic containers and particularly to mounting clips to attach a component to the wall of a plastic container, such as a fuel tank.

[0002] Plastic containers are widely used to store fluids and other materials to take advantage of a number of benefits including weight savings and corrosion resistance. One problem with plastic containers is that many types of plastics used to form containers allow permeation of vapors through the container walls. To prevent permeation, manufacturers have added permeation resistant layers to the containers. Even if a container includes a permeation resistant layer, as items are attached, permeation pathways may be created where the permeation resistant layer is pierced.

[0003] One particular area in which manufacturers have strived to address permeation is vehicle fuel tanks. As emission standards have become more stringent, manufacturers have attempted to move fuel system components, and connector lines within the tank to minimize permeation pathways by limiting the number of openings which pierce the permeation resistant layer.

[0004] The problem with placing components in a container that is subject to movement, such as a fuel tank, is that certain components such as connector lines may contact the container walls during movement causing undesirable noises and vibrations. Further, movement of the components increases the stress and wear rates which may result in decreased component service life.

[0005] One method of attaching components, such as vapor valve lines, and wiring harnesses to the walls of the tank is to create a die lock in the molded tank. Creating a die lock is generally difficult, expensive, and occasionally impossible due to geometry constraints. In fact, in most forming processes used to create fuel tanks and similar containers, it is almost impossible to create a die lock, much less multiple die locks.

[0006] Some manufacturers have attempted to address these problems by adding clips after the container is formed. Some of these clips are attached with adhesive to the sidewalls of the container. However, certain chemicals or fuels stored in the container may degrade the adhesive over time so that it no longer forms a secure bond with the container walls. Another method of attaching clips to the container walls is by hot plate welding. Hot plate welding involves heating the surface of the clip, as well as a portion of the surface of the tank, and then placing the respective heated areas of the clip and tank in contact with each other to form a bond. After the clips are welded to the surface of the tank, the components are then placed in the tank. Problems with hot plate welding include increased manufacturing costs; penetration or degradation performance of the permeation resistant layer; by the heating of the container wall; and the difficulty in assembling without first creating a large opening in the tank to facilitate placement of components in the interior of the tank. A large opening may create a large permeation area, which defeats the benefits of reducing evaporative emissions by placing the components in the fuel tank.

[0007] A further deficiency of container wall mounting clips is that they have a specific mounting surface that must be properly oriented to the exterior surface of the container to provide proper assembly and adequate bonding. A problem with many of these clips is that over time a percentage of them fail to securely retain the component. A clip may fail to retain a component if the retention members of the clip are too large or small for the component. Wear or stress of the component may occur as the clip rubs against the component. If the retention members are weakened, the clip may lose its grip on the component, causing wear, stress, noise, and vibration concerns. If the component is removed and replaced within the retention members during servicing, this may weaken or break the retention members.

SUMMARY OF THE INVENTION

[0008] In view of the above, the present invention is directed to a clip for retaining components against the walls of a plastic container and a related method of securing components to the container. The clip traps a component in a plurality of continuous folds and may be secured to the tank using its outer surfaces.

[0009] The present invention is also directed to a method for attaching a component to a container wall. The method includes forming a clip having a plurality of folds axially arranged around the longitudinal axis of the clip, securing a component with the clip and bonding the folds to the container through the latent heat from formation of the container.

[0010] Further scope of applicability of the present invention will become apparent from the following detailed description, claims, and drawings. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The present invention will become more fully understood from the detailed description given here below, the appended claims, and the accompanying drawings in which:

[0012] FIG. 1 is a perspective view of the clip;

[0013] FIG. 2 is a front elevational view of the clip;

[0014] FIG. 3 is a perspective view of a clip attached to the container wall and retaining a component; and

[0015] FIG. 4 is a sectional view of the clip taking along lines 4-4 in FIG. 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0016] A clip constructed in accordance with the illustrated embodiment is shown in FIG. 1 and designated 10. The clip 10 generally includes a tubular body 12 having a plurality of folds 14, which give the clip 10 a corrugated appearance. The clip 10 may be operatively coupled to a component 40 to form an accessory assembly for attachment to a container. As shown in FIG. 3, the clip 10 is attached to a container 30 (inside or outside) to securely retain a component 40 such as a wiring harness, fuel line, or vapor line. The clip 10 is attached to the container by melting the folds 14 to the container 30 to form a bond area 34 (FIG. 4). While a variety of melting techniques may be used, in the illustrated embodiment, the folds 14 are melted to the container 30 through the latent heat from the formation of the container 30.

[0017] The tubular body 12 may vary in size, shape, and configuration to accommodate various components 40 and attach to various container geometries. In the illustrated embodiment, the tubular body 12 has a circumferential shape that completely encircles a component 40 to prevent the component from being released by the clip 10. The complete encirclement of the component 40 also allows various sized components 40 to be retained by the clip 10, even if the component 40 is much smaller than the retaining tubular body 12. The clip 10 preferably does not have an opening along the longitudinal axis 26 and preferably does not provide snap fit retention of a component 40. The clip 10 secures the component 40 by complete encirclement of the component 40. This complete encirclement further minimizes the frequency with which the component may become free due to stress, wear, age, or a force exerted upon the components. In assembly, the component 40 is attached to the clip 10 by being passed through the tubular body 12, therefore, so long as the component 40 fits within the tubular body 12, it will be securely retained within the clip 10. The clip 10 may be configured to snugly retain the component 40 to prevent vibrations by the component 40.

[0018] The tubular body 12 includes a plurality of folds 14. The folds 14 may extend along the entire length of the tubular body 12, as illustrated in FIG. 1, or along a portion of the tubular body 12 (not illustrated). The folds 14 include ridges 16 and grooves 18, which may be formed in a variety of sizes, shapes, or configurations. For example, the ridges 16 and grooves 18 may be rounded, pointed, or have flat apexes 17 and nadirs 19. The height difference between the ridges 16 and the grooves 18 may vary as well as the pitch between adjacent ridges 16 or grooves 18. The configurations of the ridges 16 and the grooves 18 may also be varied along the tubular body 12 in a non-uniform manner to allow for better attachment to certain oddly shaped geometric configurations. In the illustrated embodiment, the folds 14 are somewhat axially aligned around the longitudinal axis 26. The shape formed by this axial alignment may be a continuous spiral like the threading on a screw or nut or as individual rings. The folds 14 also provide flexibility to facilitate bending around or over certain geometric configurations of the container 30, as well as better direct and secure the component 40. The length of the tubular body 12 may depend on various considerations such as space, geometry, and the required retention force.

[0019] The outside diameter 22 of the tubular body 12 is formed by the apexes 17 of the ridges 16, while the inside surface 24 may be formed by the nadirs 19 of the grooves 18. The inside surface 24 may be determined by the size of the component 40 as well as if it is desirable to tightly hold the component 40 or allow it to slide somewhat freely through the tubular body 12. In an alternative embodiment, the inside diameter 24 may have a relatively smooth surface (not shown) with projections therefrom forming the ridges 16. The outer ridges 16 provide a bonding surface for the clip 10 to be attached to a container as described below.

[0020] The container 30 may be formed out of a variety of materials depending on the application. In the illustrated embodiment, the container 30 is formed through a thermal process. Examples of well known thermal processes to form containers such as fuel tanks for vehicles include blow molding, twin sheet forming, thermo-forming, and roto-molding.

[0021] For material compatibility, the clip 10 is generally formed from the same, or other suitably compatible, material with the container 30. If the container 30 includes a multi-layer wall as shown in FIG. 4, the clip 10 is typically formed from materials similar to the layer to which it is bonded. Forming the clip 10 from a compatible material as the container 30 allows for ease of attachment of the clip-10 during manufacturing. In the illustrated embodiment, the clip 10 is formed from a polyethylene, preferably low-density polyethylene or high-density polyethylene. To improve the melting characteristics of the clip 10, the clip may be formed out of a material having a lower melting point than the container 30. Within a suitably short period after formation or during formation of the container 30, the clip 10 is attached to the container 30. More specifically, the apexes 17 are melted to the container 30 to form a bond area 34. The shape and height of the ridges 16 and apexes 17 may be varied to provide an optimal bond between the tubular body 12 and the container 30. The ridges 16 should be sized and shaped to melt in a manner suitable to form the bond area 34 while preventing deformation of the inner surface 24 of the tubular body 12. Preventing deformation of the inner surface 24 may prevent any potential damage to the component 40 retained within the clip 10. The thickness of material used to form the clip 10 as well as the ridges 16 may depend on the material selected and how well that material conducts heat. The conduction of heat is related to how well the ridges 16 melt to the container 30. An exemplary clip, formed from high-density polyethylene and suitable for attachment to the walls of a polyethylene container, may have a wall thickness of 0.6 mm. Of course, the ridges 16 may have the suitable thickness while the thickness may vary for other parts of the clip 10. For example, a clip 10 may have ridges with a set thickness and thicker grooves 18 to protect the component 40 secured within the clip 10 from being deformed when the ridges 16 are melted to the container 30 to form the bond area 34.

[0022] The above described configuration and technique facilitate suitable bonding of the container 30 and clip 10 in a variety of clip orientations including tight radius bends. The clip 10 may also be bonded in any orientation around the clip's 10 longitudinal axis 26, as shown in FIG. 3. Prior art clips include an opening that was directed way from the container surface and required careful placement during attachment. The clip 10 of the present invention completely encircles a component 40 so that the rotational position of the clip 10, about the axis 26, does not matter.

[0023] The assembly of the present invention is efficient as well as cost saving during the manufacturing process. In the illustrated embodiment, the clips 10 are first attached to the components 40. More specifically, the component 40 is passed through the tubular body 12 until the clip 10 reaches a desired location on the component 40. As shown in FIG. 3, more than one clip 10 may be used to route components 40 around items attached to the container 30 or over curved surfaces and complex geometries. After the component 40 is disposed within the passage 28, the clip 10 is ready to be attached to the container 30. Of course, it should be readily recognized by one skilled in the art that the above described sequence of steps may be varied. For example, the clips 10 may first be attached to the container 30 and then the components 40 may be disposed within the passage 28 and secured to the clips 10.

[0024] As noted above, the clips 10 are secured to the container 30 while the container 30 is at a suitably elevated temperature to permit the latent heat to provide attachment. For example, if the container 30 is manufactured by forming, as in the described embodiment, the clip 10 is attached shortly after container 30 is formed by pressing the tubular body 12 against the surface of the container 30 so that the latent heat from the formation of the container 30 melts the apexes 17 of the ridges 16 to form the bond area 34. In the illustrated embodiment, the container 30 preferably has a latent heat of at least 120° C. more preferably 180° C. to 233° C. and yet more preferably 198° C. to 205° C. to melt the ridges 16 of the exemplary clip 10 described above to the container 30. These temperatures may vary depending on the materials used to form the container 30 as well as the material used to form the clip 10 and the thickness of the walls of the clip 10. Of course, if necessary, the container may be reheated to attach the clips 10.

[0025] Alternative methods of attachment may be used if the container 30 does not have enough latent heat when the clip 10 is to be attached. One such method that does not require heat is ultrasonic welding. Another such method is where melted plastic is placed on the container 30 where the clip 10 is to be attached. The clip 10 is then placed into the melted plastic so that upon cooling, the clip 10 is bonded to the container 30. Yet another method is where the clip 10 is placed against the container 30 and hot air is blown against the clip 10 and container 30 until they melt to form a bond area 34.

[0026] The foregoing discussion discloses and describes an exemplary embodiment of the present invention. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims that various changes, modifications and variations can be made therein without departing from the true spirit and fair scope of the invention as defined by the following claims.

Claims

1. A clip for securing a component, said clip comprising: a generally tubular body having a plurality of ridges and a continuous internal surface to receive and completely encircle the component.

2. The clip of claim 1, wherein said tubular body includes a longitudinal axis, said ridges being axially aligned along said longitudinal access.

3. The clip of claim 1, wherein said tubular body includes grooves between said ridges, said grooves defining said continuous internal surface.

4. The clip of claim 1, wherein said tubular body is formed from a material compatible for heat bonding.

5. The clip of claim 4, wherein said material is polyethylene.

6. A component attachment assembly comprising: a component; and a clip having a plurality of ridges and a continuous internal surface to receive and completely encircle said component.

7. The assembly of claim 6, wherein said clip includes a longitudinal axis, said ridges being axially aligned along said longitudinal access.

8. The assembly of claim 6, including a container, said container being formed from a material compatible for heat bonding with said clip.

9. The assembly of claim 8, wherein said clip is attached to said container with said ridges, said container and said ridges forming a bond area.

10. The assembly of claim 9, wherein said container is formed from a material having a first melting point, said clip being formed from a material having a second melting temperature lower than said first melting temperature.

11. The assembly of claim 8, wherein said container is formed from a high density polyethylene and said clip is formed from a low density polyethylene.

12. The assembly of claim 8, wherein said container is a fuel tank for a vehicle.

13. The assembly of claim 6, wherein said clip includes grooves between said ridges, said grooves defining said continuous internal surface.

14. A method of attaching a component to a container comprising: forming a clip having a plurality of ridges axially arranged about a longitudinal axis, said clip having a continuous interior surface; forming the container by a thermal process resulting in latent heat at a mounting surface; placing said clip against said mounting surface to melt said folds to said fuel tank to form a bond area.

15. The method of claim 14 wherein said clip includes a plurality of grooves between said ridges, said interior surface being defined by said grooves.

16. The method of claim 15 wherein said interior surface defines a passageway.

17. The method of claim 16 including the step of assembling the component into said passageway.

18. The method of claim 14 wherein the component is a vapor valve line, a wiring harness or a fuel delivery line.

19. The method of claim 14 wherein said ridges and said grooves are flexible to allow said clip to attach to curved geometric surfaces.