The present invention generally pertains to fastening machines and more particularly to a pierce nut insertion tool.
It is well known to install pierce nuts in sheet metal panels. Exemplary installation machines are disclosed in the following U.S. Pat. No. 3,108,368 entitled “Method of Sizing and Installing a Pierce Nut in a Panel” which issued to Steward on Oct. 29, 1963; U.S. Pat. No. 6,257,814 entitled “Self-Attaching Fastener, Method of Forming Same and Method of Attachment” which issued to Müller on Jul. 10, 2001; U.S. Pat. No. 6,925,698 entitled “Method of Feeding and Installing Self-Attaching Nuts” which issued to Goodsmith et al. on Aug. 9, 2005; and U.S. Pat. No. 6,957,483 entitled “Self-Diagnosing Pierce Nut Installation Apparatus” which issued to Woods on Oct. 25, 2005. All of these patents are incorporated by reference herein. Various of these conventional machines, however, require complex cam-rotated fingers or spring loaded ball bearings biased to engage a separated nut aligned with a ram prior to ram extension; these complex moving parts are subject to wear and damage, are difficult to service, and are of heightened concern since they also contact against the high force ram. Furthermore, these conventional machines do not allow for independent control and timing of a nut feeding mechanism. Moreover, it can be a challenge to strip the nut from connective wires, and then orient and center the pierce nut relative to the die throughout the ram and nut travel.
U.S. Pat. No. 5,172,467 entitled “Installation Apparatus for Installing Self-Attaching Fasteners” which issued to Muller on Dec. 22, 1992, discloses a pneumatically driven piston for shuttling a single stud. This patent is incorporated by reference herein. This apparatus, however, is overly simplistic and can only push a single stud from an intermediate supply tube per stroke, thereby incurring long cycle times and misfeed concerns. The piston is externally mounted and requires expensive external valve control and connections by the user.
In accordance with the present invention, a pierce nut installation tool is provided. In another aspect, a pierce nut feeding mechanism has a mechanically independent driver or actuator from that of a punch. Yet another aspect provides a fluid actuated pierce nut feeder, more preferably with an internal valve and/or control arrangement to advantageously reduce installation complexity and increase cycle speed. A further aspect of the present tool employs a member, attached to a punch, that retains a pierce nut prior to fastening of the nut to a workpiece. A serviceable pierce nut feeding mechanism is provided in yet another aspect of the present tool.
The present tool is advantageous over conventional machines. For example, the independent actuator for the present pierce nut feeding mechanism allows the operator to change settings on a programmable controller in order to vary a stroke length or end distances, and also to vary the timing of the feed mechanism relative to a punch actuator. This can additionally be varied between different types of pierce nuts and workpiece configurations. In the internally valved and/or controlled configuration, external customer installation complexity is reduced while still allowing for the force and cycle speed benefits of fluid actuation; expensive sensors for the piston location are also not required with this approach. The present tool advantageously accurately centers and orients the pierce nut relative to the punch and die with minimal tool components. A manual feeding mechanism for the pierce nut is also employed in addition to an automatically powered actuator. Furthermore, the low profile body and nut feeding mechanism of the present tool is advantageously configured to place the pierce nut closer to edges and flanges of workpieces than many traditional machines. The present tool provides more space between a bottom of a punch-side tool and the workpiece. Additional advantages and features of the present invention will be found in the following description and accompanying claims, as well as in the appended drawings.
An alternate embodiment of a pierce nut insertion tool 31 is illustrated in
Pierce nuts 33 each have a generally rectangular top view periphery 51 and an internally threaded central hole 53. A set of pierce nuts 33 are held together in a linear string by a pair of frangible wires 55 secured within corresponding upper grooves in each pierce nut. Pierce nuts 33 are fed into a generally L-shaped rack or body 57 which is longitudinally moveable relative to base 41.
Referring to
Body 57 includes a guide block 121 and a nose plate 122. Guide block 121 has a laterally elongated track or depressed channel within which pierce nuts 33 are fed. Guide block 121 is screwed to a bottom (as viewed in
Pierce nut feeding is carried out by a feeder 171 which includes a knuckle 173, a pawl 175 and piston 141. Knuckle 173 rotates about a pivot pin 177 coupled to an end of a structure 142 opposite piston 141. A compression spring 179 biases the adjacent section of knuckle 173 away from structure 142. Pawl 175 includes a generally conical end with a rounded tip, and a threaded opposite end. The threaded end of pawl 175 is received within an internally threaded socket of knuckle 173. Thus, pawl 175 can be removed from knuckle 173 and replaced when worn during normal use and maintenance. An access plate 181 is removeably attached to a side surface of body 57 to allow service access to pawl 175. Pivot pin 177 is attached to holes in a bifurcated end of structure 142 associated with piston 141, and a head of pin 177 rides within an elongated slot 185 (see
Referring to
Feeder 171 acts as follows. Piston 141 is advanced from the position of
The nut feeding is performed while piston 93 is advanced and spaces body 57 substantially away from base 41 as is shown in
Frangible wires 55 securing the leading pierce nut 33 to the remainder of the pierce nut string are severed when piston 93 thereafter retracts body 57 toward base 41 and the leading pierce nut 33 is correspondingly withdrawn adjacent a wire cutting edge 121 of guide block 121. The leading pierce nut is then ready for insertion into the workpiece as will be later discussed. Therefore, it should be apparent from the above discussion as to the present advantageous construction and ability to feed and retain the pierce nuts onto the punch assembly without the complexity of internal components as used in traditional machines.
It also noteworthy that an internally protected channel is provided for a wire 123 as is shown in
An alternate die is shown in
Furthermore, compression springs 221 are secured within corresponding cylindrical passageways 223 in die body 201. A lower end of each compression spring is secured by a laterally elongated roll pin 225 and an upper end of compression spring 221 longitudinally biases an enlarged head of an ejection or stripping pin 227, an end of which operably projects through a corresponding hole in the top surface of die body 201. This upwardly pushes the workpiece away from the die after the nut is attached to the workpiece.
During pierce nut insertion, workpiece 35 is placed upon edge 209 of die 39 while the press is in an open position, and generally simultaneous with feeding and loading of the piece nut onto the plunger. Thereafter, the upper platen or press shoe 43 is lowered which causes plunger 91 to advance the leading pierce nut 33 on top of workpiece 35, aligned with longitudinal axis 199. The lower surface of pierce nut will act in conjunction with edge 209 of die 39 to first pierce and sever a generally rectangularly shaped blank 251, corresponding to the intersection of edge 209 and inner walls 211. Blank 251 exits die 39 through bore 213 and an attached tube. Next, the remaining interior edge 253 (see
The piercing and clinching of the workpiece to the nut only occurs for the primary formation 203 of die 37 and not for the supplemental formation 205 in the preferred construction. Supplemental formation 205 is provided as a replacement piercing and clinching formation after wear has occurred to the primary formation. After which, the die is unscrewed from the corresponding platten or shoe 45 of the press, reversed, and then reattached thereto. This secondary formation provides for a very simple, inexpensive and convenient replacement in a single piece and integrated manner.
Base 41 and body 57 are preferably machined from hard coated aluminum to minimize weight. Plunger 91 and punch 85 are preferably machined from 4140 hot rolled steel and 6150 hot rolled steel rods, respectively; the plunger is then hardened and ground to about Rc 40-44. Moreover, die body 201 is preferably machined from an M2 steel rod.
A preferred embodiment of the present pierce nut insertion tool 301 is shown in
A punch assembly 351, including a punch 353 and plunger 355, are generally the same as with the prior embodiment. It is alternately envisioned, however, that a solid and rigid plunger that only abuts against an upper surface of a pierce nut 357 without entering a hole in the nut, can be used although various advantages of the prior embodiment may not be realized. Punch assembly 351 serves to linearly drive each nut 357 from a leading feed position aligned with a punch axis to a piercing and clinching position against a workpiece 535. A conventional die with a single clinching formation can be used on an opposite side of the workpiece.
A detent mechanism 371 can best be observed in
Referring now to
Opening of body 309 from the closed position of
In the
It is noteworthy that the internally valved construction of the present embodiment provides a considerably faster cycle time then with an externally valved approach. Furthermore, no controller programming is required for nut feeding with the preferred embodiment arrangement while this embodiment additionally simplifies installation set-up of the nut feeding mechanism in a fool-proof manner. Furthermore, proximity sensors are not required to sense piston location for nut feeding thereby saving additional expense, packaging space and maintenance concerns.
While various constructions of a pierce nut insertion tool have been disclosed, alternate embodiments may be employed. For example, hydraulic fluid actuators or electromagnetic actuators can be used for moving the body relative to the base and/or moving the feeder in some of the embodiments, however, various advantages of the present tool may not be achieved. Furthermore, the collet-like plunger may have three, four or a greater number of flexible legs, however, various advantages of the present tool may not be realized. Alternately, the die may include more than two of the piercing and clinching formations. Moreover, different, additional or varying locations of fasteners, sensors, fluid passageways and connectors may be utilized, but this may forfeit certain advantages of the present tool.
The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. It is intended by the following claims to cover these and any other departures from the disclosed embodiments which fall within the true spirit of this invention.
The present application is a divisional application of U.S. patent application Ser. No. 13/308,583, filed on Dec. 1, 2011, which claims priority to U.S. Provisional Patent Application Ser. No. 61/419,376, filed on Dec. 3, 2010, both of which are incorporated by reference herein.
Number | Name | Date | Kind |
---|---|---|---|
3108368 | Steward | Oct 1963 | A |
3766628 | Grube | Oct 1973 | A |
3942235 | Goodsmith et al. | Mar 1976 | A |
3946479 | Goodsmith et al. | Mar 1976 | A |
4164072 | Shinjo | Aug 1979 | A |
4242793 | Matthews et al. | Jan 1981 | A |
4313261 | Ladouceur | Feb 1982 | A |
4348796 | Smallegan | Sep 1982 | A |
4384667 | Smallegan et al. | May 1983 | A |
4555838 | Muller | Dec 1985 | A |
4574453 | Sawdon | Mar 1986 | A |
4670978 | Fickes et al. | Jun 1987 | A |
4700470 | Muller | Oct 1987 | A |
4722647 | Sawdon | Feb 1988 | A |
4785529 | Pamer | Nov 1988 | A |
4835848 | Schimmel | Jun 1989 | A |
4911592 | Muller | Mar 1990 | A |
5161303 | Maynard et al. | Nov 1992 | A |
5172467 | Muller | Dec 1992 | A |
5181315 | Goodsmith | Jan 1993 | A |
5299351 | Takahashi | Apr 1994 | A |
5339983 | Caple | Aug 1994 | A |
5487215 | Ladouceur | Jan 1996 | A |
5502884 | Ladouceur | Apr 1996 | A |
5502888 | Takahashi et al. | Apr 1996 | A |
5522129 | Shinjo | Jun 1996 | A |
5533250 | Ladouceur | Jul 1996 | A |
5560094 | Ladouceur et al. | Oct 1996 | A |
5619788 | Schmidt | Apr 1997 | A |
5657536 | Shinjo | Aug 1997 | A |
5713116 | Nickerson et al. | Feb 1998 | A |
5722139 | Ladouceur et al. | Mar 1998 | A |
5953813 | Sickels et al. | Sep 1999 | A |
6018863 | Altrock | Feb 2000 | A |
6021562 | Boster et al. | Feb 2000 | A |
6226854 | Ladouceur et al. | May 2001 | B1 |
6257814 | Muller | Jul 2001 | B1 |
6263561 | Sickels et al. | Jul 2001 | B1 |
6357209 | Shinjo | Mar 2002 | B1 |
6442830 | Vrana | Sep 2002 | B1 |
6446833 | Morishima | Sep 2002 | B1 |
6526650 | Gaskin | Mar 2003 | B2 |
6560846 | Shioya et al. | May 2003 | B1 |
6578258 | Boyer | Jun 2003 | B1 |
6631827 | Goodsmith et al. | Oct 2003 | B2 |
6820327 | Vrana | Nov 2004 | B2 |
6832431 | Bloch et al. | Dec 2004 | B2 |
6893198 | Couillais et al. | May 2005 | B2 |
6925698 | Goodsmith et al. | Aug 2005 | B2 |
6954976 | Ladouceur et al. | Oct 2005 | B2 |
6957483 | Woods | Oct 2005 | B2 |
6993831 | Vrana | Feb 2006 | B2 |
6997659 | Vrana et al. | Feb 2006 | B2 |
7032296 | Zdravkovic et al. | Apr 2006 | B2 |
7152297 | Ladouceur et al. | Dec 2006 | B2 |
7237996 | Vrana | Jul 2007 | B2 |
7260893 | Calhoun et al. | Aug 2007 | B2 |
7338245 | Ladouceur | Mar 2008 | B2 |
7367893 | Vrana et al. | May 2008 | B2 |
7427180 | Ladoucer et al. | Sep 2008 | B2 |
7475473 | Lang et al. | Jan 2009 | B2 |
8302293 | Dehlke | Nov 2012 | B2 |
8881364 | Sawdon et al. | Nov 2014 | B2 |
8899089 | Shinjo | Dec 2014 | B1 |
20030164381 | Goodsmith | Sep 2003 | A1 |
20040123708 | Savoy et al. | Jul 2004 | A1 |
20040181937 | Woods | Sep 2004 | A1 |
20070274804 | Woods | Nov 2007 | A1 |
20080201934 | Ward et al. | Aug 2008 | A1 |
Number | Date | Country |
---|---|---|
0580907 | Feb 1994 | EP |
1373633 | Nov 1974 | GB |
Entry |
---|
Screen shots of “Arnold Shinjo Fastening Systems,” YouTube website video (3m:27s) observed at http://www.youtube.com/watch?v=GWr4yxRLr7c (published on Internet prior to Dec. 3, 2010); 2pp. |
Screen shots of “Haeger M8 nut installation,” YouTube website video (0m:39s) observed at http://www.youtube.com/watch?v=iw0ioWa6LOw (published on Internet prior to Dec. 3, 2010); 3pp. |
Humphrey® (HKV-7), “Valve Catalog,” Humphrey Products Company, Kalamazoo, MI USA—www.humphrey-products.com (published at least as early as Nov. 28, 2011); 99pp. |
Number | Date | Country | |
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20150026950 A1 | Jan 2015 | US |
Number | Date | Country | |
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61419376 | Dec 2010 | US |
Number | Date | Country | |
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Parent | 13308583 | Dec 2011 | US |
Child | 14514757 | US |