Elastic tube alignment system for precisely locating components

An elastic tube alignment system for the mating of components utilizing the principle of elastic averaging. A plurality of geometrically separated elastic tube (male) alignment features are disposed on a first component, while a plurality of one-to-one corresponding aperture (female) alignment features are provided on a second component. During the mating of the components, each elastic tube and its respective aperture provide elastic deformation, which, on average, precisely aligns the components.

TECHNICAL FIELD

The present invention relates to location features for aligning of components during a mating operation. More particularly, the present invention relates to a plurality of mutually spaced apart elastic tube alignment features of a first component which elastically deform on average when mated to receiving aperture alignment features of a second component to thereby precisely align the first and second components during a mating operation.

BACKGROUND OF THE INVENTION

Currently, components which are to be mated together in a manufacturing process are mutually located with respect to each other by 2-way and/or 4-way male alignment features, typically upstanding bosses, which are received into corresponding female alignment features, typically apertures in the form of holes or slots. There is a clearance between the male alignment features and their respective female alignment features which is predetermined to match anticipated size and positional variation tolerances of the male and female alignment features as a result of manufacturing (or fabrication) variances. As a result, there can occur significant positional variation as between the mated first and second components which contributes to the presence of undesirably large and varying gaps and otherwise poor fit therebetween.

By way of example,FIGS. 1 through 3illustrate the prior art location modality for the aligning of two components as they are being mutually mated.

A first component10has a plurality of male alignment features in the form of an upstanding elongated rib12and spaced therefrom an upstanding four-pronged stud14. A second component16has a plurality of female alignment features in the form of a narrow slot18disposed at an end and a wide slot20disposed at the opposite end. The additional slots22of the second component16are intended to provide clearance for threaded fasteners24to be screwed into screw receiving holes26of the first component10.

As best shown atFIG. 2, the elongated rib12is loosely received into the narrow slot18, wherein the spacing30between the sides18′ of the narrow slot and the sides12′ of the elongated rib allow spacing therebetween for accommodating manufacturing variances. Similarly, as best shown atFIG. 3, the pronged stud14is loosely received into the wide slot20, wherein the spacing30between the sides20′ of the wide slot and the sides14″ of the prongs14′ of the pronged stud allow spacing therebetween for accommodating manufacturing variances. For example, the spacing (or gap, or clearance)30between the male and female alignment features may be 0.6 mm, whereby the error of mating of the first component to the second component may be up to about 1.2 mm as a cross-car and up-down float.

In operation, as the first and second components are mated together, the initial contact therebetween occurs when the elongated rib passes into the narrow slot and the pronged stud passes into the wide slot, whereby the first and second components are brought into a general alignment to one another. The larger size of the narrow slot in relation to the elongated rib and the larger size of the wide slot in relation to the pronged stud allow the mating to proceed smoothly and effortlessly as the first and second components mate, even if there is present manufacturing variance in terms of size and position of the alignment features. Problematically, however, there is considerable float as between the elongated rib in relation to the narrow slot and as between the pronged stud and the wide slot. This float (or play), as mentioned above, allows for the first component to be aligned relative to the second component generally, but not precisely. When the threaded fasteners are screwed in, any misfit of alignment becomes manifest, and the visible joint between the two components may be irregular, have too large a gap, be unbalanced in appearance, etc., in any event the misfit of alignment rendering the fit unacceptable for a Class A finish.

Accordingly, what remains needed in the art is to somehow provide an alignment modality for the mating of components, wherein when mating is completed there is a lack of play as between the male and female alignment features so as to provide a precision alignment, yet the aligned mating proceeds smoothly and effortlessly each time.

SUMMARY OF THE INVENTION

The present invention is an elastic tube alignment system for the precise mating of components, particularly motor vehicle components, wherein when mating is completed there is a lack of float (or play) as between the male and female alignment features so as to provide a precision alignment with stiffened positional constraint, yet the aligned mating proceeds smoothly and effortlessly each time.

The elastic tube alignment system according to the present invention operates on the principle of elastic averaging. A plurality of geometrically separated elastic tube (male) alignment features are disposed on a first component, while a plurality of one-to-one corresponding aperture (female) alignment features are provided on a second component, wherein the elastic tube alignment features have a diameter exceeding a cross-section of the aperture alignment features. However, the first and second components may each have some of the elastic tube alignment features and some of the aperture alignment features so long as they one-to-one correspond so that they are mutually engageable with one another. During the mating of the first component to the second component, each elastic tube alignment feature respectively engages its corresponding aperture alignment feature. As the elastic tube alignment features are received into the aperture alignment features, any manufacturing variance in terms of position and size of the elastic tube and aperture alignment features is accommodated by elastic deformation, on average, at the interface between the elastic tube and aperture alignment features. This elastic averaging across the plurality of elastic tube and aperture alignment features provides a precise alignment as between the first and second components when they are mated relative to each other, and yet the mating proceeds smoothly and easily.

In accordance with the present invention, the elastic averaging provides a precise alignment of the components within a variance X′, defined by X′=X/√N, where X is the average manufacturing variance of the elastic tube alignment features and the aperture alignment features, and N is the number thereof. Thus, the needed clearance for the male and female alignment features of the prior art is obviated by the present invention.

According to the present invention, the elastic tube alignment features are elastically deformable by elastic compression of the tube wall of the elastic tube, which deformation is preferably resiliently reversible. In an exemplar application of the present invention, the elastic tube alignment features are connected (typically integrally) with a first component in upstanding, perpendicular relation to a predetermined surface of the first component. Further according to the present invention, it is possible, but not required, for the aperture alignment members to be elastically deformable by elastic expansion of the aperture wall of the aperture, which deformation is preferably resiliently reversible. In an exemplar application of the present invention, the aperture alignment features are disposed at a second component, typically as a slot or a hole in a predetermined surface of the second component, wherein the diameter of the elastic tube alignment features exceeds the cross-section of the aperture alignment features, whereby elastic deformation occurs as each elastic tube alignment feature is received into its respective aperture alignment feature. The process of mating with precise alignment is both smoothly and easily performed. This is enhanced by a tapering (smaller diameter with increasing height) of the elastic tube alignment features so as to facilitate their initial entry into the aperture alignment features, and by beveling of the aperture wall of the aperture alignment features so as to locally pronounce the elastic deformation at the interface of the aperture wall with the tube wall.

In operation, as the first and second components are mated together, the initial contact therebetween is at the plurality of geometrically spaced apart elastic tube alignment members passing into their one-to-one corresponding aperture alignment features. Because of the larger size of the diameter of elastic tube alignment features relative to the cross-section of the aperture alignment features, an elastic deformation occurs at the interface therebetween, and this deformation is averaged over the geometrical distribution of the plurality of elastic tube alignment features. The alignment becomes precise when the first and second components have fully mated because the tapering of the elastic tube alignment features provides a largest diameter to the cross-section of the aperture alignment features when the first and second components have arrived at final mating. When an affixment modality is implemented, such as for example threaded fasteners, heat staking, sonic welding, push nuts, clips, etc., the precise alignment becomes manifest, and the visible joint between the two components is a perfect Class A finish.

Accordingly, it is an object of the present invention to provide an elastic tube alignment modality for the mating of components, wherein when mating is completed there is a lack of play as between the elastic tube and aperture alignment features so as to thereby provide a precision alignment, yet the mating proceeds smoothly and effortlessly.

This and additional objects, features and advantages of the present invention will become clearer from the following specification of a preferred embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the Drawing,FIGS. 4 through 14depict various examples of the structure and function of the elastic tube alignment system according to the present invention.

Referring firstly toFIGS. 4 through 8, the general principles of the elastic tube alignment system100according to the present invention will be detailed, wherein the elastic tube alignment system operates on the principle of elastic averaging.

A plurality of mutually separated elastic tube alignment features (serving as male alignment features)102(hereinafter referred to simply as “elastic tubes”) are disposed on a first surface104of a first component106. As best shown atFIG. 5, the elastic tubes102are upstanding in normal relation to the first surface104, wherein a mutually separated pair of elastic tubes is disposed at both a left end106′ and a right end106″ of the first component106. Each of the elastic tubes102is tubular in shape, having a tube wall102′. Preferably, the tube wall102′ defines a hollow cylinder. The tube wall102′ is elastic, being preferably stiffly elastic, wherein the shape is resiliently reversible in response to a compressive force being applied thereto. A preferred plastic material is one having elastic properties so as to deform without fracture, as for example acrylonitrile butadiene styrene (ABS).

A plurality of aperture alignment features (serving as female alignment features)110(hereinafter referred to simply as “apertures”) are disposed in a second surface112of a second component114, being located in one-to-one correspondence with the plurality of elastic tubes102; that is, for each elastic tube is a respective aperture into which it is receivable. Thus, the plurality of apertures are geometrically distributed in coordinated relationship to a geometrical distribution of the plurality of elastic tubes such that each elastic tube is receivable into its respect aperture. While the apertures110are shown as elongated slots, it is clear the aperture shape could be otherwise, such as for example an elongated hole, a generally round hole, etc. Preferably, an aperture wall116which defines the opening demarcation of the aperture alignment features102is beveled116′. A preferred plastic material for the second component114in which the apertures110are disposed is one having elastic properties so as to deform without fracture, as for example acrylonitrile butadiene styrene (ABS).

While it is preferred for the first and second components106,114to be motor vehicle components, this is not a requirement.

As depicted atFIG. 6, the diameter130of the elastic tubes102exceeds a cross-section132of the apertures110, whereby elastic deformation proceeds as each elastic tube is received into its respective aperture. As best shown atFIG. 5, the elastic deformation of the tube wall102′ is locally pronounced due to the beveling116′ of the aperture wall116, wherein there is provided a relatively small contact area as between the aperture wall contact surface116″ and the tube wall102′ (seeFIG. 5). Since the compressive force between the aperture wall and the tube wall is limited to the smaller surface area of the aperture wall contact surface, a higher compressive pressure is provided, see for example the elastic deformation136shown atFIGS. 5,7and8.

The process of mating the first component106to the second component114is both smoothly and easily performed, facilitated by a tapering (smaller diameter with increasing height, as shown comparatively atFIG. 6by distal and proximal diameters130′ and130″ of the distal and proximal ends102″,102′″ of the tube wall102′. In this regard, the tapering of the elastic tubes presents a largest diameter130″ at the cross-section of the apertures when the first and second components have arrived at final mating; further, the tapering may present a smallest diameter130′ of the tube wall at the distal end102″ so as to ease initial entry of the elastic tubes into the apertures.

During the mating of the first component106to the second component114, each elastic tube102respectively engages its corresponding aperture110, wherein as the elastic tubes pass into the apertures, any manufacturing variance in terms of position and size thereof is accommodated by elastic deformation on average of the plurality of elastic tubes and apertures. This elastic averaging across the plurality of elastic tubes and apertures102,110provides a precise alignment as between the first and second components106,114when they are finally mated relative to each other.

According to the present invention, the elastic averaging provides elastic deformation of the interface between the plurality of geometrically distributed elastic tube alignment features102and the aperture alignment features110, wherein the average deformation provides a precise alignment, the manufacturing variance being minimized to X′, defined by X′=X/√N, where X is the manufacturing variance of the elastic tube and aperture alignment features and N is the number thereof.

Further according to the present invention, it is possible, but not required, for the aperture alignment members110to be also elastically deformable by elastic expansion of the aperture sidewall, which deformation is also preferably reversible; see for example110′ atFIG. 5.

Referring now toFIGS. 6 through 8, operation of the elastic tube alignment system100according to the present invention will be detailed.

As seen atFIG. 6, the first and second components106,114are brought into close proximity with near alignment. Referring next toFIG. 7, as the first and second components106,114are mated together, the initial contact therebetween is via the plurality of geometrically spaced apart elastic tubes102passing into their one-to-one corresponding apertures110, whereduring the first and second components align to one another. The alignment is precise atFIG. 8, wherein the first and second components106,114have now fully mated. The alignment is precise because of the largest size diameter of elastic tubes relative to the cross-section of the apertures results in elastic deformation, and this elastic deformation is elastic averaged over the plurality of geometrically distributed elastic tubes. When an affixment modality is implemented, such as for example threaded fasteners (see bolts140inFIGS. 4 and 5), heat staking, sonic welding, etc., the precise alignment becomes manifest, and the visible joint between the two components is a perfect Class A finish.

A comparison betweenFIGS. 1 and 4brings attention to the advantage of the elastic tube alignment system100over the prior art alignment modality, wherein the present invention provides a stiffer assembly inherently without float, whereby, for example only two threaded fasteners140are needed, as opposed to four in the assembly ofFIG. 1.

Turning attention now toFIGS. 9 through 14a second example for implementing the elastic tube alignment system100according to the present invention will be detailed.

As shown atFIG. 9, a first, or base, component200has a Class B base rear surface202. A plurality of geometrically distributed elastic tube alignment features204are upstanding in perpendicular relation to the base rear surface202, being integrally formed therewith. As shown atFIG. 10, a second, or bezel, component206has a Class B bezel rear side208. A plurality of geometrically distributed aperture alignment features210are formed in the bezel component.

As depicted atFIG. 11, the base and bezel components200,206have been aligned relative to each other by elastic average deformation of the elastic tube features204interfacing with the aperture alignment features210according to the elastic tube alignment system100of the present invention, whereby the base component is precisely aligned with respect to the bezel component, having the aforementioned reduced manufacturing variance of X′=X/√N.

The result of the precise alignment provided by the elastic averaging is depicted atFIG. 12which shows the opposite, visible Class A side, wherein the visible joint214between the base and bezel components200,204has everywhere a perfect fit because of the elastic averaging of the elastic tubes with the apertures according to the present invention.

As can best be seen by simultaneous reference toFIGS. 11,12and13, the visible joint has local joint components disposed adjacent each elastic tube and its respective aperture. For example, the elastic tubes and apertures204,210at demarcation13ofFIG. 11is disposed adjacent a local joint component220of the visible joint214ofFIG. 12. As shown atFIG. 13, the aperture alignment feature210has an elongation axis224that is oriented parallel to the local joint component220, wherein the length exceeds the diameter230of the elastic tube alignment feature204. The cross-section226of the aperture alignment feature210is oriented perpendicular to the local joint component220, wherein the cross-section has a length less than the diameter230, thus assuring elastic deformation232, due to compressive force234, will be applied by the aperture alignment feature to the elastic tube alignment feature perpendicular to the elongation axis and the orientation of the local joint component220, thereby assuring there is provided a Class A fit at the visible joint.

Turning attention lastly toFIG. 14, some or all the elastic tubes are heat staked238to affix the base component to the bezel component. Now additionally, a third component240has been affixed to the previously affixed base and bezel components. In this regard, firstly a pair of elastic tubes244of the base component200are received into apertures246of the third component240, wherein as the elastic tubes are received into the apertures in accordance with the elastic tube alignment system100, wherein elastic averaging occurs as described above. Once fully mated with a precise alignment, threaded fasteners248are threadably engaged into screw receiving holes of the base component200.

The elastic tubes102and the apertures110may reside on either of the first and second components, and indeed, some elastic tubes and some apertures may be present at both the first and second components. By way of example,FIG. 15is a view as inFIG. 5, wherein now the elastic tube alignment system100is characterized by the first component1061having both an elastic tube and an aperture, while, likewise, the second component1141having also both an elastic tube and an aperture.

Additionally, while cylindrical elastic tubes are preferred, the shape may be non-cylindrical. For example, as shown atFIG. 16, an elastic tube1021in accordance with the present invention may have a trilobular shape and may or may not have varying thickness of the tube wall.

It will be understood from the foregoing description, several notable aspects of the present invention. The present invention: 1) eliminates the manufacturing variation associated with the clearances needed for a 2-way and 4-way locating schemes of the prior art; 2) reduces the manufacturing variation by elastically averaging the positional variation; 3) eliminates the float of components as is present in the prior art; 4) provides an over constrained condition that reduces the positional variation by averaging out each locating features variation, and additionally stiffens the joint reducing the number of needed fasteners; 5) provides more precise location of components; and, 6) provides a stiffened assembly of the mated first and second components with elimination of rattle between the components in elastic deformation with respect to each other.

To those skilled in the art to which this invention appertains, the above described preferred embodiment may be subject to change or modification. Such change or modification can be carried out without departing from the scope of the invention, which is intended to be limited only by the scope of the appended claims.