Not Applicable
1. Field of the Invention
The present invention relates generally to an apparatus for installing a fastener. More specifically, this invention is directed to a self-aligning apparatus that installs a fastener.
2. Description of Related Art
A resilient clip or spring fastener generally includes a compressible member for releasably securing an object to a base or support member. For example, automotive vehicles typically use a resilient clip or spring fastener to secure a removable vehicle trim piece or cover panel to an automotive interior panel. The resilient clip or spring fastener is mounted to a post or rib located on the inner or back surface of the trim piece or cover panel. To fasten the trim piece or cover panel to an automotive interior panel within the vehicle, the post and clip assembly is inserted and extends into a slot or opening formed in a base member or support member of the automotive interior panel. When properly aligned, the compressible portion of the resilient clip assembly secures the removable trim piece or cover panel to the base member by expanding outward against opposed edges of the opening with sufficient force to hold the trim piece or cover panel in place on the base or support member. Various designs of resilient clips or spring fasteners along with their use for attaching removable trim pieces or cover panels in automotive vehicle interiors are known in the prior art.
In many instances, the trim piece or cover panel is molded from a plastic material such as polypropylene. During the molding process, the posts, or other projecting members such as ribs or outwardly extending tabs are integrally molded with and form part of the trim piece or cover panel. The posts or projecting members are of a size and configuration to receive the resilient clip. Accordingly, after forming the trim piece or cover panel, the trim piece or cover panel is placed in a fixture wherein power operated hand tools or automated equipment installs the resilient clips on the posts or projecting members.
Various tools for attaching a resilient clip or spring fastener to a component are known in the prior art. See for example Munse, U.S. Pat. No. 3,501,827 and Munse, U.S. Pat. No. 3,702,494 both of which disclose a power operated tool including a ram assembly that drives a pusher member. The pusher member drives a resilient clip or spring fastener on a trim piece or cover panel. Buttriss, U.S. Pat. No. 4,075,748 discloses an automatic fastener emplacement mechanism for selectively applying fasteners such as spring clips to a workpiece. The mechanism includes a reciprocal ram and a nosepiece located on the ram. The nosepiece holds a fastener whereby the ram supplies the force necessary to install or place the fastener on the trim piece or cover panei.
In addition to a ram driven mechanism for installing or placing a resilient clip or spring fastener, it is also known to use a four bar linkage assembly to drive a fastener holder and correspondingly install a resilient clip held therein in a final, predetermined position on a post or projecting member of the trim piece or cover panel. Like the previously discussed ram driven apparatus, the four bar linkage assembly operates only in two directions of movement; i.e., in a reciprocal or back-and-forth manner.
One disadvantage of the prior art is that as the trim piece or cover panel cools, the post or projecting member extending from the trim piece or cover panel may shift or move, typically due to tolerance variations in the shrinkage rate and amount of the plastic forming the post or projecting member. For example, as the post or projecting member cools, variations in cooling rates may cause the post or projecting member to bend or twist resulting in the axial or mounting centerline being slightly off from its original, mold position.
To install the resilient clip or spring fastener the trim piece or cover panel is placed in a locating fixture such that the post or projecting member is positioned adjacent the clip driver. As set forth above, the driver moves back and forth in a single direction between a load position and an install position. Properly positioning the trim piece or cover panel in the locating fixture does not ensure correct installation of the resilient clip or spring fastener when misalignment of the post or projecting member occurs. Accordingly, even though an operator properly positions the trim piece or cover panel in a locating fixture, the driver will not drive the resilient clip or spring fastener into the proper position on a misaligned post or projecting member. For example, if the axis of the ram and resilient fastener holder is not in axial alignment with the axis of the post or projecting member, proper alignment of the clip will not occur and the clip will not seat properly on the post or projecting member. Misalignment or not fully seating the resilient clip on the post or projecting member may prevent attachment or at the least improper attachment of the trim piece or cover panel to the base member. In addition, it may cause improper seating or unsightly gaps or spaces between the trim piece or cover panel and the base member or the automotive inner panel.
From the above, it can be appreciated that the rigid, two position clip drivers of the prior art are not fully optimized to provide an apparatus that accounts for misalignment between the driver and the post or projecting member when installing a resilient clip or spring fastener on the post or projecting member. Therefore, what is needed is a resilient clip driver that aligns the resilient clip or spring fastener with the post or projecting member during the driving process such that the resilient clip is properly installed on the post or projecting member even if misalignment occurs between the driver and the post or projecting member.
According to the preferred embodiment of the present invention, there is provided an apparatus for installing a fastener, such as resilient clip or spring fastener on a post or projecting member of a workpiece. The apparatus accounts for misalignment between the fastener and projecting member to drive and properly seat to the fastener on the projecting member. The apparatus includes a shaft supported for reciprocal movement. A power source connected to the shaft provides power to move the shaft in a reciprocal manner. A fastener holder holds the fastener in position prior to installation. A floating coupling connects the fastener holder to the shaft. In operation, the floating coupling enables the position of the fastener holder and thereby the fastener to float such that the fastener aligns with and is properly seated on the projecting member.
Accordingly, it is an object of the present invention to provide an apparatus for installing a fastener that accommodates misalignment between the fastener and projecting member.
It is another object to provide an apparatus that enables alignment of the fastener with the projecting member when the projecting member is inclined at an angle with respect to the longitudinal axis of the shaft.
It is still another object to provide an apparatus that allows for a variance in the location of the workpiece on the fixture whereby the fastener aligns itself on the projecting member.
It is yet another object to provide an apparatus that provides three positions or stages wherein the apparatus includes a load position.
These objects and other features, aspects and advantages of this invention will be more apparent after a reading of the following detailed description, appended claims and accompanying drawings.
Turning now to
A shaft collar 22 attaches a first end 24 of a drive shaft 26 to the piston rod 18. A pillow block 28 secured to the support 14 slidably supports the drive shaft 26 for reciprocal movement. Accordingly, as the power cylinder 16 is actuated, the drive shaft 26 moves in a reciprocal manner along its longitudinal axis. A second shaft collar 30 connects a coupling shaft 32 to a second end 34 of the drive shaft 26. A resilient floating coupling 36 is attached between the coupling shaft 32 and the fastener holder 38. As illustrated in
Referring still to
To mount the floating coupling 36 to the coupling shaft 32, the coupling shaft 32 is inserted into the first bushing 52 until it extends past the first bushing 52 and into the gap 56 between the first and second bushings 52, 54. A roll pin 58 located at the first end 48 of the elastomeric body 44 extends through the bushing 52 and coupling shaft 32 to secure the floating coupling 36 to the coupling shaft 32. One end of a connection shaft 62 is positioned within a cavity 60 on the fastener holder 38. A roll pin 64 extending through the fastener holder 38 and the connection shaft 62 secures the fastener holder 38 to the connection shaft 62. The fastener holder 38 is secured to the floating coupling 36 by inserting the connection shaft 62 into the second bushing 54 until it contacts the coupling shaft 32. A roll pin 66 extends through the second end 50 of the elastomeric body 44 and through both the second bushing 54 and the connection shaft 62 to secure the connection shaft 62 and correspondingly the fastener holder 38 to the resilient floating coupling 36. Accordingly, the respective centerlines of the coupling shaft 32 and the connection shaft 62 are coaxial.
The connection shaft 62 includes an arcuate or curved surface 72 located on the end 70 of the connection shaft 62 located in the elastomeric body 44 of the floating coupling 36. The arcuate or curved surface 72 contacts the flat or planar end 74 of the coupling shaft 32. Accordingly, the power cylinder 16 transmits the axial load necessary to install the retainer clip 42 through the drive shaft 26 and coupling shaft 32 to the connection shaft 62 and correspondingly to the retainer clip 42 through the fastener holder 38. Providing an arcuate or curved surface 72 facilitates both angular and rotational movement of the fastener holder 38 with respect to the coupling shaft 32.
As the illustrated in
Accordingly, as set forth above, the floating coupler 36 enables the fastener holder 38 and retainer clip 42 contained therein to shift both laterally and longitudinally to properly align and position the retainer clip 42 on the post or projecting member 68. The floating coupling 36 enables the fastener holder 38 and correspondingly the retainer clip 42 contained therein to rotate about its centerline or longitudinal axis and move longitudinally to align the centerline of the fastener holder 38 and retainer clip 42 with the centerline of the post 68 thereby accommodating angular variations of the post or projecting member 68. Thus, the floating coupling 36 of the present invention provides a mechanism to reorient the lateral, longitudinal, and angular position of the corresponding fastener holder 38 and retainer clip 42 to properly seat the retainer clip 42 on the base 80 of the post or projecting member 68.
Turning now to
As set forth previously, if misalignment occurs when the retainer clip is being driven on to the post or projecting member 68, the floating coupling 36 allows movement of the fastener holder 38 and correspondingly the retainer clip 42 such that the retainer clip 42 aligns itself to the orientation of the post or projecting member 68 such that it is properly attached and seated on the base 80 of the post or projecting member 68. Accordingly, since the retainer clip 42 wants to center itself on the post 68, the floating coupling 36 moves as necessary to compensate for any misalignment between the retainer clip 42 and the post 68.
Thus, the present invention provides an apparatus to properly install a resilient retainer clip or spring fastener to a trim piece or cover panel wherein the apparatus functions to self-align the retainer clip to the post or projecting member and completely locate or attach the retainer clip on the base of the projecting member. The present invention overcomes misalignment and tolerance variation caused by material shrinkage, fixture tolerances and any angularity or other misalignment of the post resulting in proper attachment of the retainer clip to the trim pad. As set forth above, the apparatus transmits a linear axial force to drive the fastener onto the post while the floating coupling compensates for misalignment between the post or projecting member and retainer clip.
While the present invention has been described in terms of a preferred embodiment, it is apparent that other forms could be adopted by one skilled in the art. In other words, the teachings of the present invention encompass any reasonable substitutions or equivalents of claim limitations. Accordingly, the scope of the present invention is to be limited only by the following claims.