Patent Application
20180257201
The use of rigid collets for holding tubing and other workpieces during welding operations has often been preferred over split or adjustable collets, due to the ability of the rigid collets to minimize misalignment between the workpieces being welded (e.g., due to thermal stresses). Referring to
According to an aspect of the present application, a collet member for fixturing a workpiece may be configured to reduce heat transfer away from the clamped workpiece, by modifying a portion of the collet to provide one or more of: a reduced collet mass, a reduced workpiece contact surface, a workpiece engaging material having a reduced thermal conductivity, and a workpiece engaging material having an increased porosity.
According to another aspect of the present application, a collet member for fixturing a workpiece may be produced using additive manufacturing techniques (e.g., 3D printing) to facilitate fabrication of more complex collet geometries, including, for example, collets having portions configured for reduced collet mass and/or reduced workpiece contact surface. In other exemplary embodiments, additive manufacturing techniques may be used to fabricate collets having clamping features configured to facilitate fixturing of non-standard workpiece shapes (e.g., non-cylindrical shapes, fittings having flanged or hex-shaped ends). In still other exemplary embodiments, additive manufacturing techniques may be used to fabricate rigid collets having varying material properties (e.g., thermal conductivity) across the diameter of the collet.
Accordingly, in an exemplary embodiment, a collet member for fixturing a workpiece includes a monolithic collet body having a clamping block engaging outer portion with a first thermal conductivity, and a workpiece engaging inner portion with a second thermal conductivity less than the first thermal conductivity.
In another exemplary embodiment, a method of fabricating a collet member for fixturing a workpiece includes, using an additive manufacturing process, forming a monolithic collet body including a clamping block engaging outer portion having a first material property, and a workpiece engaging inner portion having a second material property different from the first material property.
In another exemplary embodiment, a collet member for fixturing a workpiece includes a monolithic collet body having a clamping block engaging outer wall portion, a workpiece engaging inner wall portion, a plurality of rigid, radially extending members extending between the outer wall and the inner wall to define a plurality of cavities, and a first radial wall on a first axial side of the collet body, defining a first closed end of the plurality of cavities.
In another exemplary embodiment, a method of fabricating a collet member for fixturing a workpiece includes, using an additive manufacturing process, forming a monolithic collet body including a clamping block engaging outer portion and a workpiece engaging inner portion including a workpiece engaging surface configured to engage a non-cylindrical portion of a workpiece.
Further advantages and benefits will become apparent to those skilled in the art after considering the following description and appended claims in conjunction with the accompanying drawings, in which:
While various inventive aspects, concepts and features of the inventions may be described and illustrated herein as embodied in combination in the exemplary embodiments, these various aspects, concepts and features may be used in many alternative embodiments, either individually or in various combinations and sub-combinations thereof. Unless expressly excluded herein all such combinations and sub-combinations are intended to be within the scope of the present inventions. Still further, while various alternative embodiments as to the various aspects, concepts and features of the inventions—such as alternative materials, structures, configurations, methods, circuits, devices and components, software, hardware, control logic, alternatives as to form, fit and function, and so on—may be described herein, such descriptions are not intended to be a complete or exhaustive list of available alternative embodiments, whether presently known or later developed. Those skilled in the art may readily adopt one or more of the inventive aspects, concepts or features into additional embodiments and uses within the scope of the present inventions even if such embodiments are not expressly disclosed herein. Additionally, even though some features, concepts or aspects of the inventions may be described herein as being a preferred arrangement or method, such description is not intended to suggest that such feature is required or necessary unless expressly so stated. Still further, exemplary or representative values and ranges may be included to assist in understanding the present disclosure, however, such values and ranges are not to be construed in a limiting sense and are intended to be critical values or ranges only if so expressly stated. Still further, exemplary or representative values and ranges may be included to assist in understanding the present disclosure, however, such values and ranges are not to be construed in a limiting sense and are intended to be critical values or ranges only if so expressly stated. Parameters identified as “approximate” or “about” a specified value are intended to include both the specified value and values within 10% of the specified value, unless expressly stated otherwise. Further, it is to be understood that the drawings accompanying the present application may, but need not, be to scale, and therefore may be understood as teaching various ratios and proportions evident in the drawings. Moreover, while various aspects, features and concepts may be expressly identified herein as being inventive or forming part of an invention, such identification is not intended to be exclusive, but rather there may be inventive aspects, concepts and features that are fully described herein without being expressly identified as such or as part of a specific invention, the inventions instead being set forth in the appended claims. Descriptions of exemplary methods or processes are not limited to inclusion of all steps as being required in all cases, nor is the order that the steps are presented to be construed as required or necessary unless expressly so stated.
The Detailed Description merely describes exemplary embodiments and is not intended to limit the scope of the claims in any way. Indeed, the invention as claimed is broader than and unlimited by the exemplary embodiments, and the terms used in the claims have their full ordinary meaning. For example, while specific exemplary embodiments in the present application describe collets for use with weld fixtures in orbital welding systems, one of more of the features described herein may additionally or alternatively be applied to other types of welding systems, or for use in other types of fixturing applications. Additionally, while the geometries and arrangements of many of the collets described herein are such that their production is facilitated by additive manufacturing, other manufacturing methods may be utilized to fabricate collets having one or more of the features described herein, such as, for example, stacked plate assembly, machining, welding, brazing, and casting (e.g., investment casting, sand casting, lost wax casting).
According to an aspect of the present application, a collet member for a weld fixture may be configured to provide for reducing heat transfer away from a fixtured workpiece during welding. Referring to
The workpiece engaging inner portion material of the collet body may additionally or alternatively be configured to provide other desirable properties, including, for example, increased elasticity, corrosion behavior/resistance, and/or density.
While variations in materials or material properties in the collet member may be accomplished by mechanically fixing outer radial and inner radial components together to form the collet body, according to another aspect of the present application, additive manufacturing may be utilized to produce a monolithic collet body having the desired properties across the radial thickness of the collet body. Examples of additive manufacturing techniques that may be utilized include, for example: laser powder bed fusion (direct metal laser sintering or “DMLS,” selective laser sintering/melting or “SLS/SLM,” or layered additive manufacturing or “LAM”), electron beam powder bed fusion (electron beam melting or “EBM”), ultrasonic additive manufacturing (“UAM”), or direct energy deposition (laser powder deposition or “LPD,” laser wire deposition or “LWD,” laser engineered net-shaping or “LENS,” electron beam wire deposition). Providing the collet body as a single, monolithic component may eliminate assembly costs, reduce component wear, reduce adverse effects from heat cycling, improve corrosion behavior (galvanic effects, crevice, stress corrosion cracking), and reduce lead time to manufacture.
According to another aspect of the present application, heat transfer away from a fixtured workpiece may be reduced by reducing the material mass of the collet member, and/or providing cavities or air gaps in the collet member that impede thermal conduction. In one such embodiment, the intermediate portion 153 of the collet body 151 may include a plurality of rigid, radially extending members 155 (e.g., ribs, pins, fins, blades, etc.) extending between the outer portion 152 and the inner portion 154 to define a plurality of cavities 156.
While the inner wall portion 254 of the collet body may provide a semi-cylindrical workpiece engaging surface 254a, as shown in
In the collet members 250, 350 of
Additive manufacturing techniques for fabricating collet members, as described herein, may additionally be used to fabricate special, customer specific colleting configurations, for example, without requiring expensive and time-consuming casting processes. These techniques may be used, for example, to produce collet members having alternative geometries. For example,
The inventive aspects have been described with reference to the exemplary embodiments. Modification and alterations will occur to others upon a reading and understanding of this specification. It is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
This application claims priority to and all benefit of U.S. Provisional Patent Application Ser. No. 62/466,763, filed on Mar. 3, 2017, for WELD COLLET, the entire disclosure of which is fully incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62466763 | Mar 2017 | US |
