WO1995021334A1

WO1995021334A1 - A retaining clip and fastener assembly

Info

Publication number: WO1995021334A1
Application number: PCT/US1995/001216
Authority: WO
Inventors: Robb M. Fultz
Original assignee: Emhart Inc.
Priority date: 1994-02-01
Filing date: 1995-01-31
Publication date: 1995-08-10

Abstract

A retaining clip (16) and fastener assembly (10) for engaging a male connector (18) to couple a first workpiece (20) to a second workpiece (22). The fastening assembly (10) includes a nut (12), the retaining clip (16) and a washer or stamping (14). The retaining clip (16) has a center portion (66) with a center hole (70) therethrough and a plurality of resilient arms (68) which extend radially outward from the center portion (66). The center hole (70) has a diameter (1) larger than the head portion (38) of the nut (12) such that the head portion (38) is rotatably received therein and (2) smaller than the flange portion (40) of the nut (12). The resilient arms (68) connect to the washer or stamping (14) via a snap fit such that the flange portion (40) of the nut (12) abuts the top of the washer or stamping (14).

Description

A RETAINING CLIP AND FASTENER ASSEMBLY Field of the Invention

This invention relates to a retaining clip and fastener assembly for engaging a male connector to couple two parts or workpieces together. More specifically, this invention relates to a fastener assembly having a resilient retaining clip for rotatably coupling a nut to a washer or a metal stamping via a snap-fit.

Background of the Invention

Traditionally, nuts and washers have been separate elements when fastening an assembly together with a threaded fastener or bolt. This practice, however, has disadvantages. For instance, it is often ergonomically inefficient, may increase production cost, may increase the number of necessary parts and part numbers carried for inventory and may decrease the quality of the final product.

To eliminate these disadvantages, the nut and washer or stamping are commonly combined into one assembly, i.e., are preassembled. In one form, the nut and washer are connected by the displacement of metal from either the washer or the nut into a groove or cavity of the other. Specifically, the two parts are commonly combined by using a flange nut having a pilot or extension extending downwardly from the flange face and coupling the washer to the nut by upsetting or deforming the pilot around the washer.

This technique also has disadvantages. Some applications do not lend themselves to this style of assembly due to the loss in bearing area of the washer. Additionally, this type of assembly may not allow rotation between the nut and washer which is often preferable because such permissible rotation reduces and/or controls the frictional surface forces and thus, controls the relative torque and tension relationship of the fastener to sufficiently secure the assembly parts or workpieces together. Also, because this method requires permanent metal deformation, the nut and washer are usually combined prior to being heat-treated and prior to the final finishing, such as coating or plating. Thus, the prior attachment of the nut and washer can result in difficulties because of the additional processing steps necessary after the nut and washer are attached. Finally, assembling the nut and washer in this way is time consuming. For an example of a fastener assembly where the washer is deformed when attached to the washer, see U.S. Patent No. 4,986,712 to Fultz.

Other fastening assemblies connect the nut and washer into a single assembly without permanently deforming the metal. For an example of such a prior fastening assembly, see U.S. Patent 4,900,209 to Reynolds.

However, this type of assembly also has several disadvantages. For example, it is costly and time consuming to manufacture, since it must be stamped from metal, and to assemble.

In view of the above, it is apparent that a need exists for a fastening assembly that is inexpensive and easy to manufacture, easy to assemble and install, sufficiently fastens an assembly together and still allows the nut and washer to rotate relative to each other. This invention addresses these needs in the art, along with other needs which will become apparent to those skilled in the art once given this disclosure.

Summary of the Invention

This invention provides a retaining member for attaching a nut to a workpiece such as a washer or a stamping. The retaining member has a center portion which has a center hole therethrough. The center hole has a diameter which is greater than the head portion of the nut but less than the flange portion of the nut. Accordingly, the head portion is rotatably received within the center hole of the center portion, however, the flange portion of the nut cannot pass through the center hole. The retaining member also includes resilient extending arms which extend radially outward from the center portion. The extending arms are designed to engage the workpiece via a snap fit connection such that the workpiece is adjacent to the flange portion of the nut.

In some embodiments, the resilient extending arms have downwardly extending sections at the outer ends thereof. These downwardly extending sections connect to the workpiece via snap fit.

In yet other embodiments, the downwardly extending sections of the extending arr include a flange which extends substantially perpendicular to the extension section. The workpiece is received by the flange in a snap fit connection.

In further embodiments, the center portion of the retaining clip is substantially flat and circular. The retaining clips and fastening assemblies according to this invention have several advantages over prior fastening assemblies.

One advantage of the retaining clips and fastener assemblies according to this invention is that the retaining clips snap onto the fastening members or nuts for easy assembly.

Another advantage of the retaining clips and fastener assemblies according to this invention is that the fastening member or nut is rotatably coupled to the first workpiece or washer for easy installation.

A further advantage of the retaining clips and fastener assemblies according to this invention is that they allow the entire bearing surface of the first part or washer to engage a workpiece, which is necessary in certain applications to sufficiently couple the parts together.

A further advantage of the retaining clips and fastener assemblies according to this invention is that they are relatively easy and inexpensive to manufacture. Brief Description of the Drawings

Referring to the drawings which form a part of this disclosure:

Fig. 1 is a top plan view of a first embodiment of a fastener assembly in accordance with the present invention, with a bolt extending upwardly through the nut;

Fig. 2 is a cross-sectional view of the fastener assembly illustrated in Fig. 1 taken along line 2-2, showing the nut and bolt in side elevation for clarity; Fig. 3 is a top plan view of a second embodiment of a fastener assembly in accordance with the present invention, with the bolt extending upwardly from the nut;

Fig. 4 is a cross-sectional view of the fastener assembly illustrated in Fig. 3 taken along line 4-4, with the nut and bolt shown in side elevation for clarity;

Fig. 5 is a top plan view of a third embodiment of a fastening assembly in accordance with the present invention, with the bolt extending upwardly from the nut;

Fig. 6 is a cross-sectional view of the fastening assembly shown in Fig. 5 taken along line 6-6, with the bolt and nut shown in side elevation for clarity;

Fig. 7 is a top plan view of a fourth embodiment of a fastening sub-assembly in accordance with the present invention; and Fig. 8 is a cross-sectional view of Fig. 7 taken along the line 8-8, with the nut shown in side elevation for clarity.

Detailed Description of the Invention

Referring to the Figures, and in particular Figures 1 and 2, one embodiment of a fastening assembly, fastening assembly 10, for engaging a male connector or bolt to couple a washer or first workpiece to a second workpiece according to this invention is illustrated.

Fastening assembly 10 includes a fastening member or nut 12, washer 14 and a retaining member or clip 16, and is designed to couple two workpieces or parts, such as workpieces 20 and 22 together.

Nut 12 is a conventional and well known flange nut and, therefore, is only described generally. Preferably, nut 12 includes longitudinal axis 30, first end 32, second end 34, threaded hole 36, hexagonal head portion 38 (normally referred to in the industry as the hex portion) and flange portion 40. Nv 12 is formed of metal. Threaded hole 36 extends from first end 32 to second end 34 along longitudinal axis 30 and receives and threadedly couples bolt 18 within nut 12. Hex portion 38 is formed at first end 32 of nut 12 and the hexagonal shape provides for tr. ^htening by a tool, such as a wrench. Flange portion 40 includes top side 46 and bottom side 48. Top side 46 is integrally and unitarily coupled to hex portion 38 and tapers angularly outwardly and downwardly away from hex portion 38 toward second end 34 of nut 12. Bottom side 48 is preferably flat and extends perpendicularly to longitudinal axis 30.

Washer 14 is also conventional and well known and thus, will only be described generally.

Washer 14 includes first top surface 50, second bottom surface 52, hole 54, center portion 56 and outer portion 58. Washer 14 is substantially circular and curved and is formed of metal.

Hole 54 extends from top surface to bottom surface 52, is centered around longitudinal axis 30 in alignment with threaded hole 36 of nut 12 and receives bolt 18 therethrough when fastening ssembly 10 is properly assembled. Center portion 56 is sunk relative to outer portion 50, creating the curved shape of washer 14. Center portion 56 is adjacent and surrounds hole 54. Outer portion 58 extends upwardly and outwardly from center portion 56 forming an outer edge 60.

When fastening assembly 10 is properly assembled, top surface 50 at center portion 56 abuts bottom side 48 of flange portion 40 of nut 12 and bottom surface 52 at center portion 56 abuts workpiece 20.

Retaining clip 16 includes first retaining portion 66 and a plurality of arms 68. Preferably, clip 16 is molded from a polymer and is flexible and resilient.

First retaining portion 66 is flat, circular and has center hole 70 extending therethrough. Center hole 70 has a diameter larger than the largest diameter of hex portion 38 of nut 12, but smaller than the diameter of flange portion 40. Thus, when fastening assembly 10 is properly assembled, hex portion 38 of nut 12 is received within center hole 70, but flange portion 40 is prevented from exiting center hole 70.

Arms 68 extend radially outwardly from first retaining portion 66 substantially perpendicular to longitudinal axis 30. In this embodiment, clip 16 has three arms spaced venly apart around first retaining portion 66, as illustrated in Fig. 1. Arms 68 each include a downwardly extending segment 72 at the outer end thereof with a retaining flange 74 formed at the end of each segment 72. Downwardly extending segments 72 are spaced axially from nut 12 and extend substantially parallel to longitudinal axis 30. The distance from longitudinal axis 30 to (1) the inner surface of each segment 72 and (2) outer edge 60 of washer 14 is substantially equal to provide a snap-fit between clip 16 and washer 14.

Flanges 74 extend inwardly from the lower ends of segments 72 toward longitudinal axis 30 and form a contacting surface 76, as seen in Fig. 2. Contacting surfaces 76 are spaced axially from nut 12 and face substantially upwardly. Contacting surfaces 76 also extend substantially perpendicular to longitudinal axis 30 and form a shelf which engages second side 52 of washer 14 when fastening assembly 10 is properly assembled. Retaining clip 16 thereby rotatably couples nut 12 to washer 14. Assembly and Operation

To rotatably couple nut 12 and washer 14 together, retaining clip 16 is inserted over hex portion 38 of nut ₁₂ such that hex portion 38 is received within center hole 70 of retaining clip 16 and first retaining portion 66 is adjacent top side 46 of flange portion 40 of nut 12. Then, washer 14 is received into engagement with bottom side 43 of flange portion 40 of nut 12 by snapping washer 14 into retaining clip 16. Specifically, washer 14 is pushed into retaining clip 16 by the pivoting of segments 72 outwardly around outer edge 60 of washer 14 and then inwardly into engagement with washer 14.

Thus, when fastening assembly 10 is properly assembled, contacting surfaces 76 engage second side 52 of washer 14 at outer edge 60 via a snap-fit as seen in Fig. 2. Segments 72 may also engage outer edge 60 of washer 14. Threaded hole 36 of nut 12 and hole 54 of washer 14 are thereby axially aligned along longitudinal axis 30.

Next, bolt 18 is inserted through mating holes in workpieces 20 and 22, and fastening assembly 10 is inserted over bolt 18 to couple workpieces 20 and 22 together. Since nut 12 is rotatable relative to washer 14 and retaining clip 16, nut 12 is continually rotated until tight. At this point, bottom surface 52 of washer 14 engages workpie^a 20 and bolt 18 engages workpiece 22, as illustrated in :igure 2.

Thus, fastening assembly 10 quickly and easily couples workpieces 20 and 22 together. Furthermore, the surface area of second side 52 of washer 14 at center portion 56 engages workpiece 20 and provides sufficient bearing area between washer 14 and workpiece 20 to sufficiently couple fastening assembly 10 to workpieces 20 and 22 and couple workpieces 20 and 22 together.

Fastening assembly 10 can be used in virtually in any environment to fasten any two parts or workpieces together. However, it is specifically designed for use on an assembly line during mass production to decrease the overall assembly time, for example, on an automotive assembly line. Fastening assembly 10 improves the assembly time on assembly lines since nut 12 and washer 14 are preassembled and independently rotatable. Thus, bolt 18 is easily and quickly insertable through nut 12 and washer 14 to couple the two workpieces or parts 20 and 22 together.

Second Embodiment of Figs. 3 and 4

A second embodiment of a fastening assembly according to this invention, fastening assembly 10a, is illustrated in Figs. 3 and 4. Fastening assembly 10a is very similar to fastening assembly 10 except that washer 14 and workpiece 20 are replaced by a metal stamping 114, which is commonly any automotive part stamped or formed from a metal sheet, and retaining clip 116 has been redesigned accordingly. Accordingly, only the differences between fastening assemblies 10 and 10a will be discussed in detail.

Stamping 114 includes top surface 120, bottom surface 122, legs 124, openings 126 and hole 128. When fastening assembly 10a is properly assembled, top surface 120 abuts bottom side 48 of flange portion 40 of nut 12 and bottom surface 122 engages workpiece 22 (except where legs 124 are formed), as illustrated in Fig. 4. Bolt 18 extends through hole 128, which is axially aligned with threaded hole 36 of nut 12.

Upwardly extending legs 124 form steps that are equally spaced around the circumference of hole 128. Legs 124 extend radially inwardly above each opening 126, forming an inner edge 130 at the innermost end. One opening 126 extends beneath each leg 124 for a distance greater than the length of legs 124. The width of openings 126 is also greater than the width of legs 124, as illustrated in Fig. 3.

Retaining clip 116 includes first retaining portion 140 and a plurality of downwardly extending segments 144 spaced equally around the outer edge of portion 140. First retaining portion 140 has center hole 142 and encircles nut 12 (as in the first embodiment) so that hole 142 receives hex portion 38 of nut 12 therethrough. First retaining portion 140 is substantially circular and flat. Segments 144 are spaced axially from nut 12 and extend substantially parallel to longitudinal axis 30. In this embodiment, clip 116 has three evenly spaced apart downwardly extending segments 144 extending from first retaining portion 140. Downwardly extending segments 144 have flanges 146 at their ends that extend outwardly away from nut 12.

Flanges 146 form a top contacting surface or shelf 148 for engaging bottom surface 122 at legs 124 to rotatably couple stamping 114 to nut 12 via a snap-fit as discussed with respect to contacting surfaces 76 of fastening assembly 10.

The distance from longitudinal axis 30 to inner edges 130 of legs 124 may be slightly less than the distance from longitudinal axis 30 to the outer surface of segments 144 to resiliently retain retaining clip 116 in place.

In operation, retaining clip 116 is placed around nut 12 and retaining clip 116 is snapped onto stamping 114. Bolt 18 is inserted through workpiece 22, and fastening assembly 10a is inserted onto bolt 18 to couple stamping 114 and workpiece 22 together as described above with respect to fastening assembly 10.

Third Embodiment of Figs, and 6

A third embodiment of a fastening assembly according to this invention, fastening assembly 10b, is illustrated in Figs. 5 and 6. Fastening assembly 10b is very similar to the previous two embodiments and includes nut 12, bolt

: '•' and retaining clip 16. The only difference is stamping

214. Since stamping 214 is the only difference, it is the only element discussed below in detail. The area of stamping 214 which engages fastening assembly 10b is very similar to curved washer 14 of the first embodiment. Specifically, stamping 214 has a first top surface 216, second bottom surface 218, center portion 222, an outer portion 224 and openings 226.

Center portion 222 has center hole 220 which extends through stamping 214 from top surface 216 to bottom surface 218 and receives bolt 18 therethrough when fastening assembly 10b is properly assembled.

Center portion 222 extends outwardly around hole 220, as in the first embodiment, so that bottom surface 218 engages workpiece 22 at center portion 222, and top surface 216 engages flange portion 40 of nut 12. Outer portion 224 extends upwardly and outwardly from center portion 222, forming a curved stamping similar to washer 14 of the first embodiment. Openings 226 are spaced equally around the circumference of hole 220 of stamping 214 between center portion 222 and outer portion 224. Openings 226 allow outwardly extending flanges 146 of downwardly extending segments 144 of retaining clip 116 to engage the bottom surface 218 at outer portion 224 to rotatably couple nut 12 to stamping 214 as discussed with respect to the other embodiments. Fourth Embodiment of Figs. 7 and 8

In some instances, it may be desirable to form a partial subassembly which includes only the nut and the retaining member. Figures 7 and 8 illustrate such a subassembly.

In this case, the fastening assembly 10c is made up of a nut 12 and a retaining member 16 which is identical to that shown in Figures 1 and 2. It will be readily apparent that this embodiment might also be used with the other retaining members such as that shown in Figures 3-6.

In the case of the subassembly 10c, the washer 14 has not yet been installed. The retaining member 16 is assembled over the hex portion 38 of the nut 12 and thereafter, the corners of the hex portion 38 of the nut 12 are staked downwardly toward the retaining member 16 to form flats or fingers 39. The tooling which performs the staking operation is arranged so that the fingers 39 are large enough to extend over a portion of the surface of the inner ring 66 of retaining member 16, and also so that the space between the top surface 46 of the flange portion 40 and the bottom surface of the fingers 39 is greater than the thickness of the retaining member 16. Thus, the retaining member 16 is itself restrained between the fingers 39 and the flange portion 40 while still permitting rotation thereof relative to the nut 12.

Other embodiments, modifications and improvements will become apparent to those skilled in the art once provided this disclosure. Such other embodiments, modifications and improvements are within the scope of this invention, as defined by the following claims.

Claims

WHAT IS CLAIMED IS:

1. A retaining member for attaching a nut to a workpiece such as a washer or a stamping, said retaining member comprising:

a center portion having a center hole which rotatably receives a first part of said nut but which has a diameter less than a cross-sectional dimension of a second part of said nut;

said retaining member having resilient extending arms extending radially outward from said center portion and designed to engage said workpiece via a snap fit connection such that said workpiece is adjacent said second part of said nut.

2. A retaining member according to claim 1 wherein

said resilient extending arms have downwardly extending sections at the outer ends of said arms;

said downwardly extending sections connecting to said workpiece via a snap fit.

3. A retaining member according to claim 2 wherein

said downwardly extending sections include a flange which extends substantially perpendicular to said extending section to engage said workpiece.

4. A retaining member according to claim 3 wherein

said center portion is substantially flat.

5. A retaining member according to claim 4 wherein

said center portion is substantially circular.

6. A retaining member according to claim 5 wherein

said retaining member has three equally spaced resilient extending arms.

7. A fastener assembly comprising

a nut having upper and lower portions, said lower portion having a cross-sectional dimension larger than any cross-sectional dimension of said upper portion;

a retainir ' member having a center portion with a hole therethrough a.. resilient arms extending radially from said center portion, said hole having a diameter larger than any cross-sectional dimension of said upper portion of said nut but smaller th-^v> at least one cross-sectional dimension of said lower f_ tion of said nut; and

a workpiece;

said extending arms being designed to engage said workpiece via a snap fit connection:

wherein said lower portion of said nut abuts said workpiece.

8. A faste - - assembly according to claim 7 wherein

said res iient arms have downwardly extending sections at the outer ends of said arms;

said downwardly extending sections connecting workpiece via a snap fit.

9. A fastener assembly according to claim 8 wherein

10. A fastener assembly according to claim 9 wherein

said center portion is substantially flat.

11. A fastener assembly according to claim 10 wherein

said center portion is substantially circular.

12. A fastener assembly according to claim 11 wherein

said retaining member has three equally spaced resilient extending arms.

13. A fastener sub-assembly comprising

a retaining member having a center portion with a hole therethrough and resilient arms extending radially from said center portion, said hole having a diameter smaller than at least one cross-sectional dimension of said lower portion of said nut, said extending arms being adapted to engage a workpiece for holding said nut adjacent said workpiece; and

said upper portion of said nut having a plurality of fingers on said upper portion, at least one cross-sectional dimension of said fingers being larger than the diameter of said hole; said retaining member being trapped between said fingers and said lower portion of said nut;

said downwardly extending sections connecting workpiece via a snap fit.

14. A fastener sub-assembly according to claim 13 wherein

15. A fastener sub-assembly according to claim 13 wherein

said center portion is substantially flat.

16. A fastener sub-assembly according to claim 13 wherein

said center portion is substantially circular.

17. A fastener sub-assembly according to claim 13 wherein

said retaining member has three equally spaced resilient extending arms.

18. A fastener sub-assembly according to claim 13 wherein

said res:^' ^ lent extending arms have downwardly extending secti .s at the outer ends of said arms;

said downwardly extending sections being adapted to connect to a workpiece via a snap fit.

19. A fastener sub-assembly according to claim 18 wherein

said downwardly extending sections include a flange which extends substantially perpendicular to said extending section.