Patent Publication Number: US-2021178510-A1

Title: Swappable retractable tool tip (srtt)

Description:
RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application No. 62/949,050, filed on Dec. 17, 2019, the contents of which are incorporated herein by reference in their entirety. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED R&amp;D 
     This invention was made with government support with MDA Robobond II, Grant No. HQ0147-18-C-7304, awarded by the Missile Defense Agency (MDA). The government has certain rights in the Invention. 
    
    
     DESCRIPTION OF RELATED ART 
     Current state of the art friction stir-welding tool holders allows for large scale and large work pieces to be welded together through friction stir welding. There are disadvantages of the current state of the art friction stir-welding tool holders. One disadvantage is that these current tools leave a keyhole feature after the tool holder is removed from the welding work pieces. Another disadvantage is that these tools are typically only able to weld large, thick work pieces. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure, in accordance with one or more various embodiments, is described in detail with reference to the following figures. The figures are provided for purposes of illustration only and merely depict typical or example embodiments. 
         FIG. 1A  illustrates an example of a Swappable Retractable Tool Tip (SRTT) in an exploded view at a perspective, according to some embodiments. 
         FIG. 1B  illustrates the example of the SRTT in an exploded view at a different perspective, according to some embodiments. 
         FIG. 2A  illustrates an example of the SRTT in an assembled configuration at a side view, according to some embodiments. 
         FIG. 2B  illustrates the example of the SRTT in the assembled configuration at a top view, according to some embodiments. 
         FIG. 2C  illustrates the example of the SRTT in the assembled configuration at a perspective view, according to some embodiments. 
         FIG. 3  illustrates an interchangeability between retractable tool tips and shoulders as elements of the SRTT, according to some embodiments. 
         FIG. 4A  illustrates an example of assembling the SRTT at a perspective view, according to some embodiments. 
         FIG. 4B  illustrates the example of assembling the SRTT at a different perspective view, according to some embodiments. 
         FIG. 5A  illustrates an example of a piston element of the SRTT at a perspective view, according to some embodiments. 
         FIG. 5B  illustrates the example of the piston element of the SRTT at a different perspective view, according to some embodiments. 
         FIG. 6A  illustrates an example of a retractable tool tip element of the SRTT at a perspective view, according to some embodiments. 
         FIG. 6B  illustrates the example of the retractable tool tip element of the SRTT at close up view, according to some embodiments. 
         FIG. 6C  illustrates the example of the retractable tool tip element of the SRTT at a side view, according to some embodiments. 
         FIG. 6D  illustrates the example of the retractable tool tip element of the SRTT at a top view, according to some elements. 
         FIG. 7A  illustrates an example of a modified blank tool holder of the SRTT at a perspective view, according to some embodiments. 
         FIG. 7B  illustrates the example of the modified blank tool holder of the SRTT at a cross-section view, according to some embodiments. 
         FIG. 8A  illustrates an example of the retractable tool tip element of the SRTT in an “extend” state at a side view, according to some embodiments. 
         FIG. 8B  illustrates the example of the retractable tool tip element of the SRTT in the “extended” state at a close up view, according to some embodiments. 
         FIG. 8C  illustrates the example of the retractable tool tip element of the SRTT in a “home” state at a side view, according to some embodiments. 
         FIG. 8D  illustrates the example of the retractable tool tip element of the SRTT in a “home” state at a close up view, according to some embodiments. 
         FIG. 9A  illustrates an example of a shoulder element of the SRTT at a perspective view, according to some embodiments. 
         FIG. 9B  illustrates the example of the shoulder element of the SRTT at a different perspective view, according to some embodiments. 
         FIG. 10  illustrates an example of an adjustable ring stopper element of the SRTT at a perspective, according to some embodiments. 
         FIG. 11A  illustrates an example of an end cap element of the SRTT at a perspective, according to some embodiments. 
         FIG. 11B  illustrates the example of the end cap element of the SRTT at a different perspective, according to some embodiments. 
         FIG. 12  illustrates an example of a flow of compressed air inside of the modified blank tool holder of the SRTT, according to some embodiments. 
     
    
    
     The figures are not exhaustive and do not limit the present disclosure to the precise form disclosed. 
     DETAILED DESCRIPTION 
     Embodiments of the disclosed technology represent a next generation of friction stir welding tools and retractable tool tips. The disclosed Swappable Retractable Tool Tip (SRTT) may be “swappable” in such a sense that it includes various tool tips (and may use conventional tool tips). Accordingly, embodiments may be implemented that are reconfigurable within the same type of device, including, at least, two (forms) such as: a conventional friction stir welding tool holder and a swappable retractable tool tip friction stir welding tool holder. 
     Embodiments of the disclosed welding tool holders may be different from prior art friction stir welding tool holders in that they have a swappable (e.g., interchangeable) tool tip that can retract into the tool holder. 
     An example SRTT  100 , shown in  FIG. 1A  and  FIG. 1B  for example, includes multiple springs with dowel pins (e.g., four springs and four dowel pins although other quantities can be used) that help guide and lock the piston (that also contains the swappable tool tip) in place during the friction stir welding process. Utilizing compressed air such as from a Computer Numerical Control (CNC) machine, a piston and a retractable tool tip (in combination) of the SRTT  100  may act like a pneumatic cylinder, with the compressed air pushing the piston/tip combination into a blank tool holder and retract the tip away from the shoulder, which may be fixed in place. 
     Embodiments of the SRTT  100  may also be configured so that retractable tool tips may be swapped based on the material being welded along with the size of the work piece being welded. This may be accomplished in some configurations be in which the tool tip is assembled with the piston via a set screw that allows a wide range of tool tips to be swapped in place. 
     One advantage of some embodiments of the SRTT  100  is the ability to work with any type of work piece, whether it is a small (e.g., thin) work piece that requires a small tool tip and a small shoulder; or a large scale work pieces that require a larger shoulder and a larger, longer tool tip. Various geometries and features can be added or removed from the retractable tool tip and the shoulder, depending on the design of the work piece that will need to be welded. 
     Not only will embodiments of the SRTT  100  be able to weld various work pieces of varying shapes and thicknesses, they will also be able to remove the keyhole. This may be achieved by including a retractable tool tip that is fixed with a piston. Compressed air may be used help push the piston up inside of the modified tool holder, pushing the retractable tool tip with it while maintaining the shoulder in place to fill in the keyhole that is left behind in the work piece. 
     Referring now to  FIG. 1A  and  FIG. 1B , exploded views of an example of the swappable retractable tool tip (SRTT)  100  are illustrated at different perspective views. The elements shown in the example of  FIG. 1A  and  FIG. 1B  include: a modified blank tool holder  105 ; a piston  110 ; a retractable tool tip  115 ; a shoulder  120 ; a ring stopper  125 ; springs &amp; dowel pins  130 ; a cover plate  135 ; screws  140 ; fittings  145 ; and an end cap  160 . 
     According to the embodiments, the modified blank tool holder  105  comprises the main mechanical housing for the SRTT  100 . The modified blank tool holder  105  can have multiple through holes (e.g., four holes) to direct air from the top of the tool holder into the mechanical housing, thereby pushing the piston  110  and the retractable tool tip  115  up, which causes the tool tip to retract. The modified blank tool holder  105  can also include at least one relief hole, which is included in a counterbore that contains the piston  110  in order to relieve the air coming into this element. 
     As seen in the examples of  FIG. 1A  and  FIG. 1B , the SRTT  100  also includes the piston  110 . The piston can comprise multiple counterbores (e.g., four counterbores) that are used to accept the springs &amp; dowel pins  130  into place. The top of the piston  110  is also threaded to be assembled with the ring stopper  125  attached thereto. The piston  110  can include multiple grooves (e.g., two grooves) that accept O-rings in order to seal the piston  110 . The retractable tool tip  115  can be assembled into the piston  110  via a through hole inside of the piston  110 , which is then fixed into the piston  110  through a set screw. 
     Also, the SRTT  100  includes the retractable tool tip  115 . For example, this retractable tool tip  115  assembles together with the piston  110  and the shoulder  120 , and locks into place with the piston  110  through a set screw. Further, according to some embodiments, the geometry and length of the retractable tool tip  115  are adjustable dimensions. By adjusting the dimensions of the retractable tool tip  115 , the retractable tool tip  115  can be optimally configured based on welding requirements for the workpiece being welded. 
       FIG. 1A  and  FIG. 1B  additionally show the shoulder  120  of the SRTT  100 . The shoulder  120  can remain fixed in place through a set screw into the cover plate  135 . The geometry and features of the shoulder  120  can also be adjustable dimensions that are based on the design requirements for the workpiece being welded. 
     The SRTT  100  can also include the ring stopper  125 . The ring stopper  125  fastens with the piston  110 . The ring stopper  125  is configured to stop the piston  110  from pushing too far into the modified blank tool holder  105 , when compressed air pushes the piston  110  up. One or more set screws can be used to lock the ring stopper  125  in place to prevent it from spinning, for example during the friction stir welding process. 
       FIG. 1A  and  FIG. 1B  shows multiple springs &amp; dowel pins  130 . In the example configuration, the SRTT  100  contains four springs and dowel pins  130 . These springs &amp; dowel pins  130  can be used to return the piston  110  and the retractable tool tip  115  to their resting position, for instance when the external force pushing on these elements (from the compressed air) is removed from the system through the relief holes in the modified blank tool holder  105 . 
     Cover plate  135  is also illustrated in  FIG. 1A  and  FIG. 1B . As a general description, the cover plate  135  encloses the entire system of the SRTT  100  together. The cover plate  135  can contain a large single hole where the shoulder  120  can be assembled thereto. In the example, the cover plate  135  comprises eight screw holes to fasten the cover plate  135  to the modified blank tool holder  105 . The cover plate  135  can also have one or more screw holes that are used to fasten the shoulder  120  thereto. 
     In the example configuration, the SRTT  100  includes multiple screws  140  (e.g., eight screws  140 ). The screws  140  can be arranged and secured to fastens the cover plate  135  to the modified blank tool holder  105 . 
     The SRTT  100  can include multiple fittings  145 . The fittings  145  can be particularly used to seal the system of the SRTT  100 , and direct the compressed air into the counterbore of the modified blank tool holder  105 . According to an example, the SRTT  100  can include four fittings  145 , where at least one of the fittings  145  has a vented hole. 
       FIG. 2  illustrates an example of the SRTT  100  in an assembled configuration. For example, when all of the elements that are described in detail with reference to  FIG. 1A  and  FIG. 1B  are assembled together, the SRTT  100  is arranged as seen in  FIG. 2 . 
       FIG. 3  illustrates the interchangeability (also referred to herein as “swappability”) feature of the SRTT  100 . In particular, the SRTT  100  can be designed to allow for swappability between, at least, the type of retractable tool tip  115  and the type of shoulder  120  that are assembled and employed as a part of the system. 
     The SRTT swappability feature and the retractability may be manifested in various configurations by the fact that the retractable tool tip  115   a  can be swapped out with a different retractable tool tip  115   b  designed for a different workpiece that will be welded. This may include swapping tooltips to accommodate workpieces of different thicknesses. In various implementations, the shoulder  120  can also be swapped out, allowing for different features to be designed onto the face of the shoulder  120 , creating the ability to customize the SRTT  100  into various configurations that can be suited for different friction stir welding applications, as shown in  FIG. 3 . 
       FIG. 3  illustrates an example of a retractable tool tip  115   a  that is configured to swap between a different retractable tool tip  115   b . For instance, the retractable tool tip  115   a  can have be longer in length than the retractable tool tip  115   b .  FIG. 3  also shows that the SRTT  100  is configured with the ability to interchange and swap between a shoulder  120   a  and a different shoulder  120   b  having differing design and dimensions. 
     The different geometries and the lengths corresponding to each of the retractable tool tips  115   a ,  115   b  respectively, along with features corresponding to each of the shoulders  120   a ,  120   b  respectively, can be designed and then swapped when necessary for the SRTT  100 .  FIG. 3  shows that the SRTT  100  is swapped from a first configuration, being assembled with the retractable tool tip  115   a  having a design that is longer, and the shoulder  120   a  having a design with a flat face (with no grooves). In the second configuration, those elements are interchanged in order to assemble the SRTT  100  with a different type of retractable tool tip  115   b  having a shorter tool tip design, and with a different shoulder  120   b  that includes grooves designed into the flat face. 
     Referring now to  FIG. 4A  and  FIG. 4B , each displays an example of assembling the SRTT  100  at a perspective view. In other words,  FIG. 4A  and  FIG. 4B  illustrate a main assembly of an example SRTT  100 . A friction stir welding tool holder shown in this example includes: a modified tool holder blank  105 ; a piston  110 ; a ring stopper  125 ; a retractable tool tip  115 ; a fixed shoulder  120 ; an end cap  160 ; compression springs &amp; dowel pins  130 ; and screws  140   a - 140   k.    
       FIG. 5A  and  FIG. 5B  illustrate an example design of a piston  110  that can be used with the SRTT (shown in  FIG. 1A ) at different perspective views. In  FIG. 5B , the design for the piston  110  is shown to include a long through hole  501  to accept the retractable tool tip upon assembly. Counterbores  502   a - 502   d  are also present to accept the compression springs and the dowel pins (shown in  FIG. 1A ). The top of the piston  110  is configured to accommodate a ring stopper (shown in  FIG. 1A ). In this example, the piston also includes grooves  503  to allow O-rings to be placed around the piston  110  to provide a seal. 
       FIG. 6A  illustrates an example of a retractable tool tip  115  of the SRTT at a perspective view.  FIG. 6B  illustrates the example of the retractable tool tip  115  of the SRTT at close up view.  FIG. 6C  illustrates the example of the retractable tool tip  115  of the SRTT at a side view.  FIG. 6D  illustrates the example of the retractable tool tip  115  of the SRTT at a top view. 
     In some embodiments, the tip itself of the retractable tool tip  115  can be adapted from conventional friction stir welding tool tips, including: the tip geometry; and the tip length. In various other embodiments, other tip geometries and tip lengths are also possible, depending on the workpiece(s) with which the SRTT is going to be used. In the examples of  FIG. 6A - FIG. 6D , the tip of the retractable tool tip  115  is shown having the same geometry to emphasize interchangeability of SRTT. 
     Referring now to  FIG. 7A  illustrates an example of a modified blank tool holder  105  at a perspective view.  FIG. 7B  illustrates the example of the modified blank tool holder  105  at a cross-sectional view. As seen in  FIG. 7A , the modified blank tool holder  105  can include counterbores  701  to fit the piston (shown in  FIG. 1A ) and the end cap (shown in  FIG. 1A ). The modified blank tool holder  105  can also include through holes  702 , which are employed in order to route compressed air into the modified blank tool holder  105  to push the piston up. 
       FIG. 8A  illustrates another example of the retractable tool tip  115  of the SRTT in an “extend” state at a side view.  FIG. 8B  shows the example of the retractable tool tip  115  of the SRTT in the “extended” state at a close up view. Alternatively,  FIG. 8C  illustrates an example of the retractable tool tip  115  of the SRTT in a “home” state at a side view.  FIG. 8D  also shows the example of the retractable tool tip  115  of the SRTT in the “home” state, but at a close up view.  FIG. 8  shows SRTT&#39;s retractable tool tip in two states (two views). In the “extended” state, shown in  FIG. 8A  for instance, the tip of the retractable tool tip  115  can be extended due to the compression springs pushing down on the piston (shown in  FIG. 1A ) where the tool tip is assembled. In contrast, when compressed air is pushing on the piston, the tip of the retractable tool tip  115  will go into its “home” state, for example as seen in  FIG. 8C , retracting into the SRTT assembly. 
     In  FIG. 9A  and  FIG. 9B , an example of a fixed shoulder  120  is shown at different perspective views. A through hole  901  is shown, where the retractable tool tip can freely move from its “extended” state to its “home” state. In  FIG. 9B , the face of the design is prominently shown, which can be altered to include additional features, depending on the work pieces that will be welded together. 
     Referring now to  FIG. 10 , an example of a ring stopper  125  design is illustrated. The ring stopper  125  can be configured to fasten into the piston (shown in  FIG. 1A ). This is to adjust how far the piston will retract when compressed air pushes on it, therefore adjusting how far the retractable tool tip (shown in  FIG. 1A ) will go into its “home” state. 
       FIG. 11A  and  FIG. 11B  show an example of an end cap  160  of the SRTT at different perspective views. 
     In  FIG. 12 , a main assembly of the example SRTT  100  is shown as a cross section view. Particularly, the example depicts how air can flow into and/or through the modified blank tool holder  105  and allow the piston (shown in  FIG. 1A ), and the retractable tool tip (shown in  FIG. 1A ), to be pushed up. For example, examples of paths for compressed air, vent air, and relief air as they flow through holes and/or the body of the modified tool holder  105  are shown. 
     As used herein, the term “or” may be construed in either an inclusive or exclusive sense. Moreover, the description of resources, operations, or structures in the singular shall not be read to exclude the plural. Conditional language, such as, among others, “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or steps. 
     Terms and phrases used in this document, and variations thereof, unless otherwise expressly stated, should be construed as open ended as opposed to limiting. Adjectives such as “conventional,” “traditional,” “normal,” “standard,” “known,” and terms of similar meaning should not be construed as limiting the item described to a given time period or to an item available as of a given time, but instead should be read to encompass conventional, traditional, normal, or standard technologies that may be available or known now or at any time in the future. The presence of broadening words and phrases such as “one or more,” “at least,” “but not limited to” or other like phrases in some instances shall not be read to mean that the narrower case is intended or required in instances where such broadening phrases may be absent.