Patent Application
20160214223
The subject matter disclosed herein relates to a part hold-down assembly, and more particularly, a part hold-down assembly for a part processing apparatus. More particularly, the present invention includes a system, method, and apparatus for use in holding and fixturing parts in an automatic apparatus for processing parts. The hold-down device is similar to the device as shown in U.S. Pat. No. 5,272,897, which is hereby incorporated by reference.
A hold-down apparatus may be used in an automatic part processing apparatus for fully automatically processing a part or work piece by methods such as shot peening and the like. Hold-down devices as shown in U.S. Pat. No. 5,272,897 use compression or resilient biasing members secured to corresponding collars by welds to hold parts or work pieces in the apparatus. As a result of repetitive use, the resilient biasing member tends to wear on the collar and/or welds. Over time, the welds could fracture or break, resulting in potential misalignment of the resilient biasing member against the collar surface. In previous hold-down devices, the resilient biasing member attaches to a planar surface of the corresponding collar, and the end of the resilient biasing member can tend to “walk” or slip off the collar if it became dislodged or the weld breaks. This can cause misalignment or axially skewed angling of the hold-down device. The present invention is an improvement on the prior art with these potential issues.
This background information is provided to provide some information believed by the applicant to be of possible relevance to the present disclosure. No admission is intended, nor should such admission be inferred or construed, that any of the preceding information constitutes prior art against the present disclosure. Other aims, objects, advantages and features of the disclosure will become more apparent upon reading of the following non-restrictive description of specific embodiments thereof, given by way of example only with reference to the accompanying drawings.
The present disclosure provides for collars which help align and secure the resilient biasing member without attachment thereto (via welds or other methods). The collars also facilitate controlled use of the resilient biasing member relative to the apparatus. Thus, the present disclose provides for an improvement on an automatic apparatus for processing parts and a part hold-down apparatus for use with the apparatus. The hold-down apparatus includes an improved assembly, including a compressible resilient biasing member and a pair of corresponding collars positioned at opposite ends of the resilient biasing member.
According to one embodiment, a part hold-down assembly is configured to retain a part. The part hold-down assembly includes an upper collar, a lower collar and a coil resilient biasing member retained between the upper and lower collar. The upper collar has a first end, the first end having an annular ledge. The lower collar has a second end, the second end having an annular ledge. The coil resilient biasing member includes a first coil end and a second coil end, the first coil end configured to engage with the annular ledge of the upper collar and the second coil end configure to engage with the second annular ledge of the lower collar.
According to another embodiment, a part hold-down assembly further includes an optional stabilization tube that is retained within a central passage of the resilient biasing member, the stabilization tube reducing or eliminating movement of the resilient biasing member in a direction that is not parallel with the direction of the central axis of the part hold-down assembly. Accordingly, the stabilization tube reduces or prevents twisting movement of the resilient biasing member in relation to the collars, which can typically cause unintentional damage to the connection therebetween, or otherwise cause malfunctioning of the resilient biasing member. In various embodiments, the stabilization tube can include one or more contact ribs that engage with an inner surface of the resilient biasing member, and/or can permit the upper shaft to extend through a shaft-receiving aperture of the stabilization tube.
According to another embodiment, an apparatus is configured to process a part. The apparatus includes a part-hold down assembly for retaining the part in the apparatus during processing. The apparatus also includes an upper shaft configured to retain the part hold-down assembly in the apparatus and a support configured to retain the part in the apparatus. The part hold-down assembly includes an upper collar, a lower collar, and a coil resilient biasing member retained therebetween. The upper and the lower collars include an annular ledge formed in corresponding surfaces to retain a portion of a corresponding end of the coil resilient biasing member therein, the corresponding ends of the coil resilient biasing member being attached to the corresponding ends of the upper and lower collars with the ends of the coil resilient biasing member being retained in the corresponding annular ledges.
These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
The present disclosure will be described hereafter with reference to the attached drawings which are given as a non-limiting example only, in which:
The exemplification set out herein illustrates embodiments of the disclosure that are not to be construed as limiting the scope of the disclosure in any manner Additional features of the present disclosure will become apparent to those skilled in the art upon consideration of the following detailed description of illustrative embodiments exemplifying the best mode of carrying out the disclosure as presently perceived.
While the present disclosure may be susceptible to embodiment in different forms, there is shown in the drawings, and herein will be described in detail, embodiments with the understanding that the present description is to be considered an exemplification of the principles of the disclosure. The disclosure is not limited in its application to the details of structure, function, construction, or the arrangement of components set forth in the following description or illustrated in the drawings. The disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of various phrases and terms is meant to encompass the items or functions identified and equivalents thereof as well as additional items or functions. Unless limited otherwise, various phrases, terms, and variations thereof herein are used broadly and encompass all variations of such phrases and terms. Furthermore, and as described in subsequent paragraphs, the specific configurations illustrated in the drawings are intended to exemplify embodiments of the disclosure. However, other alternative structures, functions, and configurations are possible which are considered to be within the teachings of the present disclosure. Furthermore, unless otherwise indicated, the term “or” is to be considered inclusive.
As shown in
As illustrated in
The resilient biasing member 42 is shown by way of illustration and not for limitation as a coil spring 42 or other compressive structure. In various embodiments, the coil spring 42 includes a first end 68 and a second end 70, and is formed to include a central passage 58 from the first end 68 to the second end 70. The coil spring 42 is formed from one or more coils 48 wrapped in a circular manner, with each wind of the coil 48 configured to be spaced apart from an adjacent wind in its nature state so as to form one or more spaces 56 between each wind. When the coil spring 42 is compressed, the coils 48 are moved together to reduce the overall distance between the first and second ends 68 and 70 of the coil spring 42. Other forms of a resilient biasing member 42 may be used to achieve the claimed invention and every other form of such member is incorporated within the scope of this disclosure to provide the structures and functions of the invention. The resilient biasing member 42 may be made of any suitable material, include metals and plastics.
The upper collar 36 includes a circumferential side 16 that extends between a top end 62 and a coil-engaging end 64 of the upper collar 36 and a plate 18 extending radially inward from the circumferential side 16. The upper collar 36, for example the coil-engaging end 64 of the upper collar 36, is configured to engage with the resilient biasing member 42 to apply a compression force onto the resilient biasing member 42, which will thereafter transfer a compression force onto the lower collar 38. The lower collar 38 includes a circumferential side 90 that extends between a bottom end 92 and a coil-engaging end 66 of the lower collar 38 and a plate 94 extending radially inward from the circumferential side 90. The lower collar 38, for example the coil-engaging end 66 of the lower collar 38, is configured to secure the second end 70 of the coil spring 42 and to permit transfer of a compressive force from the upper collar 36 to a part 22 being processed.
The hold-down assembly 20 is carried on an upper portion of the processing assembly 10 with an upper shaft 32 providing a point of contact with the processing assembly 10. In illustrative embodiments, the upper shaft 32 is coupled to the upper collar 36. In various embodiments, the upper shaft 32 extends through a portion of an coupling aperture 30 formed in the plate 18 of the upper collar 36 in order to secure the upper shaft 32 to the upper collar 36, as illustrated in
The hold-down assembly 20 further includes a lower shaft 33 that provides means for transferring the force applied by the hold-down assembly 20 to the part 22 being processed. In illustrative embodiments, the lower collar 38 is coupled to the lower shaft 33. In various embodiments, the lower shaft 33 extends through a portion of a coupling aperture 31 formed in the plate 94 of the lower collar 38 in order to secure the lower shaft 33 to the lower collar 38, as illustrated in
In illustrative embodiments, the hold-down assembly 20 further includes an optional coupling shield 84, as illustrated in
The lower shaft 33 may optionally include an end or masking portion 46 that provides a point of contact with the part being processed. The masking portion 46 includes at least a circumferential outer surface 98 and leading edge surface 52. The end or masking portion 46 can extend from a bottom end 96 of the lower shaft 33 and can be welded or otherwise fixedly attached to move with lower shaft 33. In various embodiments, the masking portion 46 may have a circumference C that is the same or greater than a circumference of the part 22 being processed. Further, the masking portion 46 may have a circumference that is the same as the circumference of the lower shaft 33. In various embodiments, the masking portion 46 is configured as part of the lower shaft 33, and the bottom end 96 of the lower shaft 33 are continuous with the leading edge surface 52.
The masking portion 46 is used to abut against a corresponding surface 50 of the part 22 in order to block or mask processing of that surface 50 of the part 22. Specifically, masking occurs by engaging the leading end surface 52 of the masking portion 46 with the corresponding surface 50 of the part 22. With the surfaces 50, 52 in face-to-face, contact the surface 50 of the part 22 is shielded or masked from the processing steps. For example, one type of process used with such processing assembly 10 may be peening. As shown in
With reference to
The resilient biasing member 42 of the hold-down assembly 20 may be made by various methods to achieve desired strength and resilient biasing member force within the hold-down assembly 20. The resilient biasing member 42 may, for instance, be subjected to a processing step as well, such as peening, to provide improved strength or stability characteristics. As illustrated in
While not described herein, reference is made to the incorporated patent, U.S. Pat. No. 5,272,897 with regard to the operation of the overall part processing apparatus. The processing assembly 10 receives a part 22 mounted on the support 24, which is then processed in an automated manner. The processing includes automated fixturing of the part hold-down assembly 20 against the part 22, rotation of the part 22 relative to the nozzles 54 and movement of the part 22 on a turntable 12 through a processing path. While the process itself is not the subject of the present application, the operation of the process is important because it highlights the need for the structures and functions of the part hold-down assembly 20 as disclosed herein.
As noted, the part hold-down assembly 20 includes specifically designed upper and lower collars 36, 38. Previous part processing apparatuses did not include any structure for retaining a resilient biasing member relative to a collar. As shown more explicitly in
The annual ledge 60 of the collars 36, 38 helps solve an important need in the present invention and processing assembly 10. The ledge 60 allows the resilient biasing member 42 to be attached to the upper and lower collars 36, 38 in a variety of ways, all of which are structurally equivalent in the broadest sense. Additionally, the use of the annular ledge 60 and the attachment of the resilient biasing member 42 relative to the collars 36, 38 should be broadly interpreted to include all of the presently known and hereafter discovered structures to achieve this function. The annular ledge 60 is provides a fixturing and locating structure for a positive engagement between the coil ends 68, 70 of the resilient biasing member 42 and the collars 36, 38. The coil ends 68 and 70 may be flattened, for instance, by machining, as illustrated in
As noted above, the attachment of the resilient biasing member 42 relative to the collars 36, 38 is intended to be broadly interpreted and always possible relative to the disclosure provided herein. The coil ends 68, 70 of the resilient biasing member 42 can be welded to the contact surfaces 40 within the corresponding ledge 60 providing weld sillets 34 between the contact surface 40 and the coil ends 68, 70. Alternatively, the coil ends 68, 70 of the resilient biasing member 42 may be welded to the corresponding ends 64, 66, respectively, of the collars 36, 38. As another alternative, other means such as strapping, interference fit, or other ways of attaching the resilient biasing member 42 to the collars 36, 38 are included within the scope of the present disclosure. In an exemplary embodiment, the annular ledge 60 can be formed with an inside diameter 72, 74 which is approximately equal to and, perhaps, slightly smaller than the corresponding outside diameter 76, 78, respectively, of the coil ends 68, 70 of the resilient biasing member 42. In this regard, a tight interference fit can be formed between the ledge 60 and the coil ends 68, 70 either eliminating the need for welding, or complementing a weld 34 connection in addition to the interference fit. Additionally as described and illustrated in
The addition of the annular ledge 60 and the attachment of the coil ends 68, 70 of the resilient biasing member 42 in the annular ledge 60 improve the operation of the mechanism and prevent problems and damage to the mechanism as well as parts. One of the problems with the previous hold-down assemblies is that when the welds attaching the coil ends 6870 to the collars 36, 38 broke or started to fail, the resilient biasing member 42 might shift or become misaligned relative to the overall axial alignment of the assembly. As an example, if one or multiple welds 34, but not all welds 34, in the hold-down assembly 20 failed, the hold-down assembly 20 might be misaligned relative to the part 22. This could cause jamming of the part 22 or breakage of the hold-down assembly 20. Furthermore, if the resilient biasing member 42 is not aligned with the part 22, it may not exert the right amount or direction of pressure onto the part 22, causing the part 22 to be susceptible to shiftage upon application of the peening process.
Furthermore, if the entire set of welds 34 failed so that the collars 36, 38, may no longer attach to the resilient biasing member 42. If this occurred mid-processing, the lower collar 38 and the masking portion 46 might be missing during the operation, resulting in peening of the end surface 50 of the part 22. These failures are problematic since the automated nature of the apparatus might result in detection of the failure of the welds 34 and hold-down assembly 20 only after several parts 22 have been processed. Also, failure of the system causes the apparatus to be taken down for repair incurring additional costs, process slow down, and the cost of the repair personnel, parts and other associated costs.
In contrast, even if a weld 34 breaks on the present embodiment as disclosed herein the coil ends 68, 70 of the resilient biasing member 42 will still be positively captured by the annular ledge 60 in the corresponding collars 36, 38. Additionally, if the parts 22 are manufactured with sufficiently tight tolerances to provide the interference fit, failure of the welds 34 may still not cause misalignment of disengagement of the parts 22 in the parts hold-down assembly 20. As a result, even weld 34 failures may not result in complete failure of the system.
Weld 34 failures can still be noticed as a result of periodic inspection and maintenance as carried out on previous hold-down assemblies. However, until the weld 34 failure or other component failure is detected through such inspection, the assembly can still operate and not incur down time, damage to components and other associated costs. It should be noted that the parts 22 being peened should not be damaged. As an example, failure to properly mask the end surface 50 of part 22 as a result of a failure of the hold-down assembly 20 might result in scrapping a part 22. This is important to not occur since the parts 22 are typically being prepared in a just in time process mode and there is little if any room to tolerate damage to parts. As a result, the peening process including the part hold-down assembly 20 must be constructed to prevent any damage to any part 22 during the processing steps.
In another illustrative embodiment, the part hold-down assembly 20 may further include a stabilization tube 100, as illustrated in
In illustrative embodiments, the stabilization tube 100 includes a first end 102 and a second end 104, and may be formed to include an optional shaft-receiving aperture 106 that extends through the stabilization tube from the first end 102 to the second end 104, as illustrated in
The stabilization tube 100 is generally configured to extend circumferentially around the central axis 14 such that the upper shaft 32 aligns with and can extend into the shaft-receiving aperture 106 of the stabilization tube 100. For instance, as noted above, the shaft 32 may be configured to extend through the coupling aperture 30 formed in the upper collar 36 and further extend through into the shaft-receiving aperture 106 of the stabilization tube 100 when the stabilization tube 100 is positioned within the central passage 58 of the resilient biasing member 42 adjacent the upper collar 36. In various embodiments, an outer surface 37 of the upper shaft 32 may abut against the inner surface 110 of the stabilization tube 100 when the shaft 32 extends within the shaft-receiving aperture 106. Alternatively, a space may exist between the outer surface 37 of the shaft 32 and the inner surface 110 of the stabilization tube 100.
In various embodiments, the stabilization tube 100 further comprises one or more contact ribs 112 that extend circumferentially away from the outer surface 108 of the stabilization tube 100 to be positioned farther away from the central axis 14 than the outer surface 108. The contact ribs 112 may each include a contact surface 114. In various embodiments, the contact ribs 112 are configured to abut against an inside surface 47 of the resilient biasing member 42, wherein the inside surface 47 of the resilient biasing member 42 generally defines the central passage 58 of the resilient biasing member 42. In exemplary embodiments, there may be three contact ribs 112 that are uniformly spaced around the outer circumference of the outer surface 108 of the stabilization tube 100, as illustrated in
The contact ribs 112 of the stabilization tube 100 are configured to provide a limited number of points of contact between the stabilization tube 100 and the resilient biasing member 42. Specifically, the contact surface 114 of a contact ribs 112 may be configured to abut against the inside surface 47 of the resilient biasing member 42. As noted above, the stabilization tube 100 is configured to provide a counteractive surface to reduce or prevent movement of the resilient biasing member 42 in a direction that is not in line with application of force F upon the resilient biasing member 42 from the part hold down assembly 20. For instance, the stabilization tube 100 can reduce or prevent movement of a coil 48 in a direction D that is orthogonal to the direction of force F being applied, wherein such movement of the coil 48 in direction D could cause the ends 68 and 70 of the resilient biasing member 42 to twist or becoming disengaged from their connection with the collars 36 and 38, thereby causing damage to or malfunction of the part hold-down assembly 20. However, the desire to prevent movement of the coils 48 in a direction that is not parallel with the direction of force F must be weighed against a concern than errant shot peening material may become lodged or stuck between the stabilization tube 100 and the resilient biasing member, which can also cause damage to the part hold-down assembly 20 with repeated, continuous use. The contact ribs 112 permit adequate stabilization of the resilient biasing member 42 to prevent undesired movement of the resilient biasing member 42, while providing a space S between the inside surface 47 of the resilient biasing member 42 and the outer surface 108 of the stabilization tube 100 that prevents or reduces the likelihood of having processing material become intentionally stuck in the part hold-down assembly 20.
In other embodiments, the contact surface 114 of the contact ribs 112 may be configured to be spaced apart from the inside surface 47 of the resilient biasing member 42 when the stabilization tube 100 is positioned within the central passage 58. In such an embodiment, the stabilization tube 100 may permit minimal movement of the resilient biasing member 42 in a direction that is not parallel with the central axis 14, such as direction D, but then block or reduce additional movement in that direction after the resilient biasing member 42 travels a predetermined or specific distance. The contact surface 114 may also be configured to be a predetermined distance away from the inside surface 47 in order to permit movement of errant processing material therebetween, thereby preventing or reducing the likelihood of such processing material being stuck, as noted above. In various embodiments, for example, the contact surface 114 may be configured to be approximately 1/16 of an inch away from the inside surface 47 of the resilient biasing member 42. Alternative dimensions of spacing are also envisioned, and may depend on the type and amount of processing material being used.
In various embodiments, a cross-sectional view of the stabilization tube 100 may be configured to have a cross-section similar to a circle with the contact ribs 112 extending outwardly therefrom, as illustrated in
In various embodiments, the stabilization tube 100 may be secured to the shaft 32 extending within the shaft-receiving aperture 106 of the stabilization tube 100. In illustrative embodiments, the stabilization tube 100 may comprise one or more screw-receiving apertures 116 that are configured to receive a set screw 117. The set screw 117 is configured to extend through the outer and inner surfaces 108 and 110 of the stabilization tube 100 and abut against the shaft 32 when the shaft is adjacent the inner surface 110 of the stabilization tube 100, retaining the shaft 32 and stabilization tube 100 in position to each other.
The stabilization tube 100 may be formed of various materials. In illustrative embodiments, the stabilization tube 100 is formed of a UHMW (Ultra High Molecular Weight) polyethylene material, which may be useful in connection with, for example, glass bead or ceramic processing material. In another illustrative embodiment, the stabilization tube 100 may be formed of steel (e.g., A2 hardened steel), which may be useful in connection with, for example, steel shot and rounded cut wire processing material. Other types of materials are envisioned within the scope of this disclosure for the stabilization tube 100, and may be dependent on the type of material being used to process the part.
By way of review, a part 22 is attached or fixtured on the support 24 of the processing assembly 10, as disclosed herein and in U.S. Pat. No. 5,272,897. The part 22 is then captured between the support 24 and the lower collar 38 of the parts hold-down assembly 20, with the part 22 being optionally captured by the upper masking portion 46 attached to the lower collar 38. The part hold-down assembly 20 includes the collars 36, 38 retaining the resilient biasing member 42 therebetween. The resilient biasing member 42 provides a degree of compressive engagement to retain the part 22 on the support 24 and may be in the form of a coil spring 42. The part hold-down assembly 20 carried on the upper shaft 32 is raised and lowered during the automated processing steps making axial alignment of the part hold-down assembly 20 relative to the part 22 carried on the support 24 an important processing step. As the part hold-down assembly 20 is axially advanced downwardly toward the part 22, the corresponding surface 52 of the masking portion 46 may engage the corresponding surface 50 of the part 22 during the processing. The processing may include, but is not limited to, peening operations. For example, the part 22 can be rotated on the lower support 24 during the processing step, during which a group of peening nozzles 54 spray peening material at the part 22 to provide processing characteristics on the part 22 surface to, in part, improve wear and durability as well as other characteristics.
The part hold-down assembly 20 includes the two collars 36, 38 securing the resilient biasing member 42 therebetween. As noted above, the collars 36, 38 include the annular ledges 60 which engage the corresponding coil ends 68, 70 of the resilient biasing member 42. As noted, the coil ends 68, 70 can be welded with a weld 34 after they are engaged in the annular ledge 60. Additionally, interference fit may be achieved by the dimensional characteristics of the coil ends 68, 70 and the corresponding annual ledges 60. Alternative embodiments of attachment to retain the resilient biasing member 42 relative to the collars 36, 38 can be obtained.
In the event of a breakage of a weld 34, the part hold-down assembly 20 can still retain the collars 36, 38 relative to the resilient biasing member 42 to facilitate ongoing processing operations of the part 22 in the overall apparatus. This prevents the resilient biasing member 42 from “walking” or slipping off of the collars 36, 38.
The part hold-down assembly 20 can further include an optional stabilization tube 100 that is retained within a central passage 58 of the resilient biasing member 42, the stabilization tube 100 reducing or eliminating movement of the resilient biasing member 42 in a direction that is not parallel with the direction of the central axis 14 of the part hold-down assembly 20. Accordingly, the stabilization tube 100 can block or prevent twisting movement of the resilient biasing member in relation to the collars 36 and 38, which can cause unintentional damage to the connection therebetween or otherwise cause malfunctioning of the resilient biasing member 42. In various embodiments, the stabilization tube 100 can include one or more contact ribs that engage with an inner surface 110 of the resilient biasing member 42, and/or can permit the upper shaft 32 to extend through a shaft-receiving aperture of the stabilization tube 100.
The foregoing terms as well as other terms should be broadly interpreted throughout this application to include all known as well as all hereafter discovered versions, equivalents, variations and other forms of the abovementioned terms as well as other terms. The present disclosure is intended to be broadly interpreted and not limited.
While the present disclosure describes various exemplary embodiments, the disclosure is not so limited. To the contrary, the disclosure is intended to cover various modifications, uses, adaptations, and equivalent arrangements based on the principles disclosed. Further, this application is intended to cover such departures from the present disclosure as come within at least the known or customary practice within the art to which it pertains. It is envisioned that those skilled in the art may devise various modifications and equivalent structures and functions without departing from the spirit and scope of the disclosure as recited in the following claims. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application is a continuation-in-part of U.S. application Ser. No. 13/798,689, filed on Mar. 13, 2013, and entitled “Hold Down and Masking Apparatus for Part Processing,” which claims the benefit of U.S. Provisional Patent Application No. 61/658,965, filed Jun. 13, 2012 and entitled “Hold Down and Masking Apparatus for Peening Operation.” The disclosures set forth in the referenced applications are incorporated herein by reference in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| 61658965 | Jun 2012 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 13798689 | Mar 2013 | US |
| Child | 15092228 | US |
