Fatigue Technology, Inc.

Roger T Bolstad

Leonard F Reid

Eric T Easterbrook

Michael A Landy

Charles M Copple

Darryl E Quincey

Louis A Champoux

Joy Sarah Ransom

Charles A Copple

Louis A Champoux, Deceased

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 tubular bushing (68) is positioned into an opening (88) in a member (84). An axially split expansion sleeve (66) is placed onto a small diameter portion (54) of an extended mandrel (10). The mandrel (10) includes an increasing diameter portion (56) and a maximum diameter end portion (58) endwise from the small diameter portion (54). The maximum diameter portion (58) is sized to fit through the tubular bushing (68). The expansion sleeve (66), while on the small diameter portion (54) of the mandrel (10) can also fit through the bushing (68). The sleeve (66) is placed on the small diameter portion (54) of the mandrel (10) with its inner end (76) against the end (78) of a sleeve positioner (40). A tubular nosepiece (16) surrounds the sleeve positioner (40), and extends axially beyond the end surface (78). The mandrel (10) is inserted through the bushing ( 68) while the bushing (68) is within opening (92). The mandrel (10) is moved to place the sleeve (66) within the bushing (68), and an end surface (41) of the nosepiece (16) against a surface portion (84) of the workpiece (88). At the same time, the end surface (43) of a nosepiece extension (39) is positioned against an end surface (82) of the bushing (68). The mandrel (10) is then pulled through the sleeve (66). Movement of the increasing diameter portion (56) and the maximum diameter portion (58) through the sleeve (66) imposes a radially outwardly directed force on the sleeve (66), causing the sleeve (66) to expand. The expanding sleeve (66) exerts a radially outwardly directed force on the bushing (68). In response, the bushing (68) is expanded radially into a secure interference fit within the opening (92) in the workpiece (88).

Method and apparatus for securing a tubular bushing in a circular opening

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 tubular bushing (68) is positioned into an opening (92) in a member (88). An axially split expansion sleeve (66) is placed onto a small diameter portion (54) of an extended mandrel (40). The mandrel (10) includes an increasing diameter portion (56) and a maximum diameter end portion (58) endwise from the small diameter portion (54). The maximum diameter portion (58) is sized to fit through the tubular bushing (68). The expansion sleeve (66), while on the small diameter portion (54) of the mandrel (10) can also fit through the bushing (68). The sleeve (66) is placed on the small diameter portion (54) of the mandrel (10) with its inner end (76) against the end (78) of a sleeve positioner (40). A tubular nosepiece (16) surrounds the sleeve positioner (40), and extends axially beyond the end surface (78). The mandrel (10) is inserted through the bushing ( 68) while the bushing (68) is within opening (92). The mandrel (10) is moved to place the sleeve (66) within the bushing (68), and an end surface (41) of the nosepiece (16) against a surface portion (84) of the workpiece (88). At the same time, the end surface (43) of a nosepiece extension (39) is positioned against an end surface (82) of the bushing (68). The mandrel (10) is then pulled through the sleeve (66). Movement of the increasing diameter portion (56) and the maximum diameter portion (58) through the sleeve (66) imposes a radially outwardly directed force on the sleeve (66), causing the sleeve (66) to expand. The expanding sleeve (66) exerts a radially outwardly directed force on the bushing (68). In response, the bushing (68) is expanded radially into a secure interference fit within the opening (92) in the workpiece (88).

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).

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Seattle, WA, United States of America

Roger T Bolstad