Fatigue Technology, Inc.

Michael A Landy

Eric T Easterbrook

Leonard F Reid

Charles M Copple

Roger T Bolstad

Darryl E Quincey

Louis A Champoux

Mark R Weiss

Richard Z Jarzebowicz

Joy Sarah Ransom

Todd L Thompson

Charles A Copple

Louis A Champoux, Deceased

Larry L Wiemann

A circular opening (54) is formed in a wall (12). A tubular shank (42) of a nut mounting unit (40) is inserted into the opening (54). The unit (40) is moved endwise to place a nut cage base (46) against the wall (12). A split sleeve (82) is installed on a small diameter portion (90) of a mandrel (M). The mandrel (M) and sleeve (82) are inserted into the tubular shank (42) from the side of the wall (12) opposite the nut cage (44). The mandrel (M) is then retracted to successfully move increasing and maximum diameter portions (90, 92) of the mandrel (M) through the split sleeve (82). The mandrel portions (92, 94) exert a radially outwardly expanding force on the split sleeve (82). The split sleeve (82) in turn imposes a radially outwardly expanding force on the tubular shank (42). This causes a plastic deformation of the tubular shank (42), creating a tight interference fit between the tubular shake (42) and the sidewall of the opening (54). In this manner, the unit (40) is firmly secured to the wall (12). Next, a nut (20) is inserted into the nut cage (44), between end stops (56, 58). A retainer spring (68) is placed over the base (24) of the nut (20), and is compressed an amount sufficient to move side portions (64, 66) together enough that they will fit between cage sidewalls (48, 50). Then, the squeezing force on the retainer spring (68) is released, allowing side portions (64, 66) to move outwardly into openings (60, 62) in the sidewalls (48, 50). In this position the sidewalls (48, 50) restrain sideways movement of the nut. The end stops (56, 58) restrain endwise movement of the nut (20). The inner spring (68) prevents movement of the nut (20) out from the nut cage (44).

Nut cage and mount

A circular opening (48) is formed in a structural wall (12). A tubular shank (28) of a nut mounting grommet (26) is inserted into the opening (48). The grommet (26) is moved endwise to place a shoulder surface (34) on the base of a nut mounting cup (30) against the wall (12). A split sleeve (54) is installed on a small diameter portion (62) of a mandrel (52) and the mandrel and sleeve (52, 54) are inserted into the tubular shank (28) from the side of the wall (12) opposite the nut receiving cup (30). The mandrel (52) is then retracted to successively move increasing and maximum diameter portions (64, 66) of the mandrel (52) through the split sleeve (54). The mandrel portions (64, 66) exert a radially outwardly expanding force on the split sleeve (54). The split sleeve (54) in turn imposes a radially outwardly expanding force on the tubular shank ( 28). This causes a plastic deformation of the tubular shank (28), creating a tight interference fit between the tubular shank (28) and the sidewall of the opening (48). In this manner, the grommet (26) is firmly secured to the wall (12). Next, a nut (24) is inserted into the cup (30) with its threaded central opening (18) in alignment with the passageway through the tubular shank (28). The sidewall of the cup (30) is deformed, to place portions of a lip (46) endwise of the nut (20), in the path of removal of the nut (20) from the cup (30). The sidewall of the cup (30) includes wrench flats (98) outwardly bounding wrench flats (100) on the nut (20).

Method of installing a nut mounting grommet

A split sleeve (S) is deposited into a sleeve loader (24, 24'), with a lower end of the sleeve (S) on a sleeve support surface (154). A mandrel (M) carried by a puller tool (10, 10') is inserted into the sleeve loader (24, 24'), and through the sleeve (S), to position the sleeve (S) on a small diameter portion (50) of the mandrel (M), and an end portion of the sleeve (S) within a nosepiece (12), against a sleeve end contacting surface (66). The tool (10, 10') is moved away from the sleeve loader (24, 24') to pull the mandrel (M) out from the sleeve loader (24, 24'). Then the mandrel (M) is inserted into an opening (16) in a workpiece (14). The tool (10, 10') is moved endwise to place the sleeve (S) within the opening (16) and a workpiece contacting end surface of the nosepiece (12) into contact with the workpiece (14). The tool (10, 10' ) is then operated to retract the mandrel (M). This moves first an increasing diameter portion (52) and then a maximum diameter portion (54) of the mandrel (M) axially through the sleeve (S). In response, the sleeve (S) is expanded radially to compress the material immediately surrounding the opening. Grip surfaces (158) on end portions of nosepiece fingers (78) grip the sleeve (S). Following retraction, the tool (10, 10') is moved away from the workpiece (14) and the sleeve (S) is pulled out from the opening (16).

Method and apparatus for split sleeve cold expansion of openings in

Nut mounting grommet

The present invention provides a method of installing a grommet within an opening in a wall of composite material. An opening (10) is formed in a wall of composite material (12). A countersink (20) is formed at one end of the opening (10). A grommet (22) is placed into the opening (10). A split sleeve (28) is placed on the small diameter portion (30) of a mandrel (32) which is attached to a power puller (36). The mandrel (32) with the split sleeve (28) is placed through the opening (10) and a grommet (22). The power puller (36) is then operated to pull the mandrel (32) back through the opening (10) and the grommet (22) thereby expanding the split sleeve (28) which in turn provides for the radial expansion of the grommet (22). During the radial expansion of the grommet (22), ends of fibers (16) are forced into the surface of the grommet (24 ). After the mandrel (32) has been pulled all the way through the split sleeve (28) both it and the split sleeve (28) are removed from the grommet (22). This leaves the grommet (22) securely fastened within the opening (10) in the composite wall (12).

Method of installing a grommet in a wall of composite material

A noncircular opening is formed in a material. A mandrel or mandrel and expansion sleeve are used for coldworking a circular region of the noncircular opening, and for forcing a hard metal insert into coldworking contact with the material immediately bordering the remaining portion of the noncircular opening. An insert may be placed within a slot to form with a circular closed end of the slot a substantially circular opening. An expansion sleeve is placed in the opening and an expansion mandrel is pulled through it, or an expansion mandrel is used alone in the opening, to coldwork the circular region of the opening. An insert may be placed within an opening and then a mandrel moved through an expansion sleeve placed in a circular opening in the insert, or a mandrel alone may be moved through the opening, to radially expand the insert and coldwork the material bounding the noncircular opening.

Fatigue life enhancement of noncircular openings

A pair of openings (14) are drilled in a workpiece (12) at locations spaced inwardly from an edge (76) of the workpiece (12). Each opening is cold-expanded by the passage of a mandrel (46') only, or a mandrel (46) and split sleeve (58), to create an annular zone of residual compressive stresses (72) in the workpiece material immediately surrounding the openings (14'). Then the workpiece (12) is cut along lines extending from the edge (76) inwardly to central regions of the cold-expanded openings (14'). The workpiece material between the two openings (14') and the two cuts (74) is removed. The edge portions (72) of the material in the vicinity of the cuts (74) and the openings (14') are machined to a final desired size and shape, to define connector slots (84) having cold-expanded round regions bounding the slots (84).

Fatigue life enhancement of dovetail connector slots and noncircular

A combined hole size gauge and oversized hole marker having either first and second sensing members (42, 44) or a single dimensionally graduated size sensing member (14) which when inserted into a hole (40) in a workpiece (38) allows the user to determine whether the hole is of at least minimum size and if it is of greater than maximum size. If the hole is oversized, a marker adjacent the oversized hole size sensing member (44) or the greater portion of the single dimensionally graduated size sensing member (18) is permitted to contact the workpiece (38) and leave an indication that the corresponding hole is oversized.

Combined hole size gauge and oversized hole marker

A pair of back-up members (32, 42) are inserted between adjacent projection (4) of a workpiece (2). Openings (36, 46) through the members (32, 42) are aligned with holes (6) through the projections (4). A wedge (54) is driven between the members (32, 42) and forces them against outer surface portions (5) of the projections (4) surrounding the holes (6) and radial end surfaces (9) of bushings (7) positioned in the holes (6). A mandrel (62) is pulled through the bushings (7) and the openings (36, 46) to install the bushings (7). Another embodiment of back-up members (132, 142) has a plurality of openings (136, 146) for use with a workpiece (102) having a plurality of rows of axially aligned holes (106). This embodiment is preferably used with a locator (70) which has two rods (74) for holding the holes (106) and openings (136, 146) in accurate alignment.

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Bellevue, WA, United States of America

Michael A Landy