US3650309A

US3650309A - Structure and use of fasteners having locking keys

Info

Publication number: US3650309A
Application number: US798686A
Authority: US
Inventors: Robert Neuschotz
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-02-12
Filing date: 1969-02-12
Publication date: 1972-03-21
Anticipated expiration: 1989-03-21

Abstract

A fastener including a threaded body to be connected to a coacting part, and a locking key received at least partially within a groove formed in the body, with the key being adapted to be driven generally axially relative to the body to a locking position, and with the groove being shaped to direct the key radially with respect to the axis of the thread and toward the material of the coacting part as the key advances generally axially, in a relation deforming the material of the coacting part by the key and thereby locking the thread against detachment from that part.

Description

United States Patent N euschotz [451 Mar. 21, 1972 [54] STRUCTURE AND USE OF FASTENERS HAVING LOCKING KEYS [21] App]. No.: 798,686

2,608,123 8/1952 Israelson ..85/23 2,783,811 5/1957 Cummaro. l5l/4l.73 3,103,962 9/1963 Neuschotz l51/41.73 3,270,792 9/1966 Neuschotz et a1 l 5 l [23 3,319,688 5/1967 Rosan et al... ..151/23 3,371,697 3/1968 James ..151/23 Primary ExaminerMarion Parsons, Jr. Att0rneyWilliam P. Green 57 I ABSTRACT A fastener including a threaded body to be connected to a coacting part, and a locking key received at least partially within a groove formed in the body, with the key being adapted to be driven generally axially relative to the body to a locking position, and with the groove being shaped to direct the key radially with respect to the axis of the thread and toward the material of the coacting part as the key advances generally axially, in a relation deforming the material of the coacting part by the key and thereby locking the thread against detachment from that part.

12 Claims, 17 Drawing Figures 42 t I l l 28 23 23 T l9 5 '-l 2o Patented March 21, 1972 3 Sheets-Sheet 2 .1. qua 5 lSa INVbNIOR fir-r oQlJEv '35 I R0552? MEuscHoTz STRUCTURE AND USE OF FASTENERS HAVING.

LOCKING KEYS CROSS REFERENCES TO RELATED APPLICATIONS Certain features of the fasteners disclosed in the present application have been shown and claimed in my copending applications Ser. No. 688,563, filed Dec. 6, 1967 entitled Lock Key Fastener Utilizing Deformed Thread As Stop Shoulder, now US. Pat. No. 3,435,870 Ser. No. 786,075 filed Dec. 23, 1968 entitled Manufacture of Fastener Utilizing Deformed Thread As Stop Shoulder", and Ser. No. 798,659 filed Feb. [2, 1969 entitled Formation And Use Of Fasteners Having Keys".

BACKGROUND OF THE INVENTION This invention relates to threaded fasteners of a type having a locking key for retaining the fastener against detachment from a part to which it has been connected, with the key being driveable generally axially relative to the body of the fastener to a locking position. The fastener is in most instances of a character having two different threads or sets of threads, one of which is connectable to the mentioned coacting part, while the other is connectable to another part in a manner securing these two parts together through the medium of the fastener. The invention will be illustrated and discussed primarily as applied to an insert device, having a generally tubular body with a first external thread and a second internal thread, though it will be apparent that the invention is also applicable to other fastener structures, such as stud arrangements in which two external threads are utilized.

In my US. Pat. No. 2,855,970 issued Oct. I4, 1958,] have shown a type of threaded fastener having axially driveable locking keys which in some respects are similar to the keys of the present invention. The keys utilized in that prior patent are carried within grooves in the fastener body, and have a first relatively thin mounting portion received within the groove, and a thicker locking portion which projects radially outwardly far enough to cut through and deform the material ofa coacting threaded part when the key is driven axially, to thereby lock the fastener against detachment from that part. The thickened locking portion desirably serves also the secondary function of engaging the coacting threaded part, upon initial connection of the fastener body thereto, in a manner limiting the extent to which these parts may be screwed together, to thus accurately predetermine the positioning of the threaded parts relative to one another. In my copending applications Ser. No. 688,563 now US. Pat. No. 3,435,870 and Ser. No. 786,075, I have shown arrangements in which means other than the locking keys themselves may be utilized for attaining this secondary relative positioning function of the keys.

SUMMARY OF THE INVENTION A major purpose of the present invention is to provide a new type of fastener structure having a locking key which is driveable generally axially to its locking position as discussed above, but in which the key need not be designed to have the mentioned thickened portion in order to attain an effective locking action, though the invention is of course not to be understood as precluding use of such a thickened portion if desired in conjunction with or as a supplement to the locking action taught in the application. In its simplest form, the key of the present invention may be much less complex in configuration than the keys of my US. Pat. No. 2,855,970, and may be correspondingly much less expensive to manufacture, less critical to install, and less critical to dimension during manufacture.

To attain these results, I so form the groove within which the locking key is received that, as the key is driven generally axially, the groove causes the key to also advance in a radial direction, so that this radial movement forces the advancing key into the material of the coacting part, to deform or cut through that material in a manner attaining a very effective locking action for retaining the parts against threaded detachment. In one form of the invention, the mounting groove has a wall which curves gradually and smoothly in a radial direction as it advances axially, and the key is sufficiently deformable to follow the curvature of that groove and be guided thereby into the material of the threaded part, and preferably into the threads of that part. In another arrangement, the key is initially disposed at an angle directing it into the material of the carrier part without bending. For maximum simplicity, the groove is in either instance initially formed to a non-undercut cross section, with the key being adapted to itself distort or cut the groove to a slightly undercut cross section as the key is driven into and within the groove, so that this undercut section serves to retain the key against radial separation from the groove, without the necessity for a secondary machining operation to undercut the groove prior to installation of the key.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and objects of the invention will be better understood from the following detailed description of the typical embodiments illustrated in the accompanying drawings, in which:

FIG. 1 is an axial section through a threaded insert formed in accordance with the invention, and shown positioned within a carrier part, with the keys illustrated as they appear prior to being driven axially to their locking positions;

FIG. 2 is a view similar to FIG. 1 but showing one of the keys after having been driven to locking position;

FIG. 2a is a perspectiverepresentation of one of the locking keys of FIGS. 1 and 2;

FIG. 3 is an enlarged fragmentary side view of the insert, taken essentially on line 3-3 of FIG. 1, without showing the carrier part;

FIGS. 4, 5 and 6 are transverse sections taken on lines 4-4, 5-5 and 6-6 respectively of FIG. 3;

FIG. 7 is a perspective view of a variational type of key;

FIG. 8 is a view similar to FIG. 3 but utilizing the FIG. 7 type of key;

FIG. 9 is a side view ofthe key of FIGS. 7 and 8;

FIG. 10 is a section taken on line 10-10 of FIG. 9;

FIG. 11 is a view similar to FIG. 2 showing a variational type of key arrangement, with the key illustrated in full lines as it appears before being driven to its locking position;

FIGS. 12 and 13 are transverse sections taken on lines 12- 12 and 13-13 respectively of FIG. 11;

FIG. 14 is a view similar to FIG. 13 but showing a variational type of key cross section;

FIG. 15 is a view similar to FIG. 11, but showing still another form of the invention; and

FIG. 16 shows the manner in which the keys of FIG. 15 may be driven to their locking positions by a special driving tool.

DESCRIPTION OF THE PREFERRED EMBODIMENTS There is shown in FIG. I a threaded insert assembly 10 as it appears when screwed into a carrier part 11, to a position in which the insert is to be locked within the carrier part. The insert assembly includes an essentially tubular insert body 12 carrying one or more locking keys l3, typically two such keys positioned at diametrically opposite locations with respect to the axis 14 of the tubular body 12. The carrier part may be formed of any appropriate material, such as aluminum, steel, another metal, a resinous plastic material, or the like. The carrier part contains a passage 15 within which the insert is received, and having internal threads 16 centered about axis 14. A tapering frustoconical annular countersink surface 17, centered about axis 14, is formed in the carrier part at the axially outer end of thread 16, adjacent a typically planar outer surface 18 of the carrier part disposed transversely of axis 14.

Insert body 12 is formed of an appropriate rigid material, usually steel or another rigid metal, and has an external thread 19 centered about axis 14 and dimensioned to mate with internal thread 16 of the carrier part. Preferably, both of these

threads

16 and 19 are of standard 60 degree configuration except as to their minor diameters, at which cylindrical modified

minor diameter surfaces

20 and 21 may be provided, which surfaces have a greater diameter and greater axial extent than they would have if thethreads were completely standard in shape and dimension. Internally, insert body 12 has a second thread 22, concentric with

threads

16 and 19 and centered about axis 14, and into which a screw, stud or other externally threaded part may be connected, to secure that part to the carrier part 11 through the medium of the insert assembly. Threads 22 may be completely standard in configuration and dimension.

At the time of manufacture of the insert assembly 10, the two keys 13 are driven partially into diametrically opposite mounting grooves 23 formed in the outer surface of body 12,

and are frictionally retained in the FIG..1 positions of partial 7 reception within those grooves during handling of the insert assembly prior to installation, so that the body 12 and keys 13 may be handled as a single effectively integral unit prior to and during installation. Each groove 23 as initially machined is preferably of a non-undercut cross section, such as that illustrated in FIG. 6, being defined at its opposite sides by two parallel planar opposite side wall surfaces 24 which lie in planes disposed parallel to axis 14 of the insert, and spaced equal distances from the axis, and from a radial plane illustrated at 25 in FIG. 6 which extends through and contains axis 14. At its radially inner side, each groove 23 has an inner wall surface 26 which faces radially outwardly. From the axially outer extremity 27 of the groove (FIG. 1), to the location designated 28 in FIG. 1, the inner wall 26 of the groove may be planar and extend directly parallel to axis 14, and perpendicular to the radial plane 25 of FIG. 6. Also, in extending between the

locations

27 and 28, inner wall 26 of the groove may be located radially inwardly of the diameter of minor diameter surfaces 21 of thread 19, far enough to enable reception of key 13 inwardly of the minor diameter of the internal thread within the carrier part 11, so that the insert assembly can be screwed to the FIG. 1 position within the carrier part without interference being afforded by engagement of the keys with the carrier part thread.

Downwardly or axially inwardly beyond the location 28 of FIG. I, the inner wall 26 of each groove 23 curves gradually and smoothly radially outwardly at 29, and after curving outwardly to an increased diameter may then curve gradually and smoothly to a more axially extending condition. The groove 23 thus extends axially through, and interrupts, the external thread 19 of the insert body, preferably through the entire axial extent of that body.

In accordance with the teachings of my copending application Ser. No. 798,659, the keys 13 are desirably so formed as to themselves deform the initially non-undercut grooves 23 to undercut cross section as the keys are driven into the grooves during assembly of the insert structure. For this purpose, each key may have an axially inner portion 32 (FIGS. 2a and 3) having two laterally projecting elongated fins 33 at its opposite sides, of a width slightly greater than the width w between the opposite side wall surfaces 24 ofthe groove. As seen in FIG. 5, these fins are located adjacent the planar undersurface 34 of portion 32 of the key, which surface engages and slides along inner wall surface 26 of the groove, with lateral continuations of undersurface 34 typically forming the undersurfaces of the fins at 34. The upper surfaces 35 of the fins may advance gradually and progressively toward the plane of surface 34 as they advance laterally, as viewed in FIG. 5.

The fins 33 of key 13 may continue from the axially inner end 36 of the key to the location 37 of FIG. 3, with the fins and keys desirably being of uniform and unchanging cross section through the entire axial distance between these points. Upwardly or axially outwardly beyond the location 37, the key may have the rectangular cross section illustrated in FIG. 4, and may define a portion 38 of the key which projects upwardly from and beyond the groove, and beyond the upper transverse end surface 39 of the tubular insert body 12, for engagement by a driving tool to drive the key axially downwardly to its locking position. As will be apparent, the entire key may initially be formed of a simple flat strip of metal having the cross section illustrated in FIG. 4, with that cross section being forged to the FIG. 5 condition downwardly beyond the location 37 of FIG. 3. The effective thickness I of the key (FIG. 1) is thus essentially uniform along the entire length of the key, except as altered by provision of the fins, with that thickness being small enough for the previously mentioned reception within the minor diameter of the carrier part threads, and with that thickness preferably being approximately equal to the depth d of the associated groove 23 inwardly beyond the minor diameter ofthread 19 (FIG. 6).

In assembling the keys 13 to insert body 12, these keys are driven axially inwardly into grooves 23, to the position of FIGS. 1 and 3, so that fins 33 of the key act to deform the initially non-undercut groove 23 to the undercut configuration of FIG. 5, which configuration acts to effectively confine the key against radially outward separation or removal from the groove. Also, such driving of the key into the groove causes the insert body to tightly frictionally hold the keys in the FIG. 1 positions with respect to the body, during handling and installation of the assembly. The undercut guideway recesses 39 formed in the opposite side walls 24 of each groove by fins 33 of course continue downwardly or axially inwardly only so far as the axially inner extremities of the fins are driven, that is to the locations 40 in FIG. 3. Axially inwardly beyond that location, each groove retains its original non-undercut cross section, as will be apparent from FIG. 6.

At the time of installation of the insert assembly into the carrier part 11 of FIG. 1, external thread 19 of insert body 12 is screwed into the internal thread 16 of the carrier part until the insert body reaches the FIG. I position, in which its outer end surface 39 is approximately flush with outer surface 18 of the carrier part, and preferably is in a slightly underflush position with respect to surface 18. In order to limit the advancement of the insert body into the carrier part at this FIG. 1 position, I preferably deform the uppermost or axially outermost turn 41 of external thread 19 axially inwardly, to the cross section illustrated in the left-hand portion of FIGS. 1 and 2, so that the undersurface 42 of this turn of the thread functions as a stop shoulder adapted to engage countersink surface 17 and halt axial advancement of the insert body at the FIG. I position. More particularly, as seen in the left-hand portion of FIG. 3, this upper end turn 41 of the thread may be deformed to a position in which it advances essentially circularly about axis 14, rather than helically. Two ways in which this end turn may be deformed to attain the discussed motion limiting function are covered in greater detail in my applications Ser. Nos. 688,563 and 786,075 and consequently no further elaboration on the structure of this deformed thread will be included in the present application.

To now describe in detail the process of installing the insert assembly 10 within carrier part 11, assume first of all that the body 12, carrying keys [3, is screwed into the carrier part to the FIG. I position, with the advancement being halted at that position by the discussed engagement of deformed portion 41 of external thread 19 with countersink 17. After the insert assembly has reached this FIG. 1 position, a user drives keys 13 axially inwardly, with a hammer or other driving tool, from the FIG. 1 position to the FIG. 2 position of the keys. As each key advances axially inwardly, it is cammed radially outwardly by the curving inner wall surface 26 of the coacting groove 23, to cut through and deform the threads of the carrier part, and thus form an effective interlock preventing unscrewing rotation of the insert body 12. During advancement of the keys relative to the insert body, the fins 33 form continuations of the guideway recesses 39' of FIG. 5. If desired, the outward curvature of groove walls 26 may be more gradual than illustrated in FIGS. 1 and 2, so that there is no necessity for the reverse curving of the insert to its more axially extending condition as indicated in the lower portion of FIG. 2. The keys I3 are of course formed of a material which is capable of bending as indicated, to enable the discussed outward deflection along the camming surface 26. An appropriate slightly deformable but relatively stiff spring steel or other metal will serve this purpose.

FIGS. 7 through 10 show another form of key which may be substituted for that shown in FIGS. 1 through 6, and in which instead of the single elongated pair of fins 33, there are provided two axially spaced pairs of laterally projecting fins 33a, formed on the axially inner portion 32a of each key 13a. These fins may have planar undersurfaces 134a aligned with and forming continuations of the planar undersurface 34a of the main body of the key, and may have upper camming surfaces 350 as they advance axially inwardly (downwardly in FIG. 9), to cam the key against the inner wall 260 of the associated groove 23a as the key is initially driven into the groove, and as it is subsequently driven to its locking position. The outer edges 135 of fins 33a may converge progressively toward one another as they advance axially inwardly, to facilitate the formation of undercut guideway recesses corresponding to those shown at 391 in FIG. 5. The key 13a is installed within an insert in the same manner discussed in connection with the first form of key, and is subsequently driven axially to a position such as that illustrated in FIG. 2 to cut through the threads of the carrier part, and lock the fastener assembly against removal from that part.

FIGS. 11 through 13 illustrate fragmentarily another form of the invention, in which one or more keys 13b (desirably two diametrically opposite keys) are mounted within two generally axial grooves 23b formed in the outer surface of insert body 12b, in a manner very similar to the arrangement of FIG. 1, but with the keys being disposed at a slight angle a with respect to the axis 14b of the insert, rather than extending directly axially as in FIG. 1. Each key 13b of FIGS. 11 through 13 may typically be of substantially the same construction as the FIG. 1 keys 13, having an axially outwardly projecting portion 38b of rectangular cross section (corresponding to the cross section of FIG. 4), and an axially inner mounting portion 32b of the FIG. 5 cross section frictionally retained and confined within groove 23b. The radially inner wall 26b of the groove may be planar and straight along its entire extent, and be disposed at the previously mentioned angle a with respect to axis 14b of the insert and its internal and external threads, so that the key is effectively guided for straight line movement axially inwardly from the full line position of FIG. 11 to the broken line position of that figure. The opposite side wall surfaces 24b of the groove are initially planar and parallel, in correspondence with surfaces 24 of FIG. 6, and are deformed by the fins 33b of the key to the undercut or dovetail cross section illustrated in FIG, 13, when the key is driven into the groove to the FIG. 11 full line position. In that position, the mounting portion 32b of the key is received radially inwardly of the minor diameters of external threads 19b on the insert, and internal threads 1611 within the carrier part 11b. As the key is driven axially inwardly to its broken line position, the key advances radially outwardly beyond the minor diameters of threads 16b and 19b, to cut through the internal threads 1612 within the carrier part, and thereby lock the insert against unscrewing rotation relative to the carrier part. This locking action is attained without the necessity for bending ofthe keys as is required in the FIG. 1 arrangement.

FIG. I4 is a view similar to FIG. 13, but showing a key 13c of slightly different cross section, in which the fins 330 are spaced slightly radially outwardly beyond the plane of the radially inner surface 34c of the key, and the engaged inner wall 266 of the groove. Also, the key of FIG. 14 has a cross section which more nearly approaches a square section than does the relatively elongated rectangular cross section of the FIG. 13 key. As will be apparent, any of numerous other crosssectional configurations may be given to the key and its fins, so long as the key is preferably effective to convert the groove from a non'undercut cross section to an undercut cross section when the key is driven into the groove.

FIG. 15 shows another variational arrangement which may be considered as identical with that of FIG. 11 except that the fins 33d of the key 13d are somewhat different, and the axially outwardly projecting driving portion 38d of the key is bent at 138 to extend directly parallel to the axis 14b of the insert and its threads, rather than at the angle 00 of the remainder of the key. The key may be initially straight at the time of installation, with portion 38d being bent to its axially extending position after the key has been driven into groove 23d. As will be apparent, the key is easier to drive by a hammer or other driving tool when its outwardly projecting portion extends directly axially, and can be driven with less chance of unwanted bending or distortion of the key during driving. The bent portion 38d of course tends to follow the finned leading portion of the key as the key is driven to its locking position, so that in that locking position the key assumes a straighter configuration than illustrated in FIG. 15. Fins 33d of FIG. 15 are typically il- -lustrated as including two axially spaced pairs of such fins,

with these fins being disposed at a slight camming angle with respect to the inner wall 26d of groove 23d, and the planar inner surface 34d of the finned portion of the key. The camming angularity serves the purpose of the angularity of surface 35a in FIG. 9, to tend to urge the key tightly against surface 26d at all times during initial installation of the key, and subsequent movement of the key axially inwardly to its locking position.

FIG. 16 shows the insert 10d of FIGS. 11 through 13, in conjunction with a special tool 43 for driving the keys to their locking positions. This tool has a first rigid pilot element 44, having an outer cylindrical surface 45 centered about axis 14b of the insert, and having an annular camming surface 46 at its leading end centered about axis 14b. Surface 46 tapers radially inwardly to a diameter less than the spacing s between the uppermost ends of the two diametrically opposed keys 13b in their FIG. 11 normal angularly disposed positions, so that when the lower tapered end of element 44 is pushed downwardly between the angularly disposed upper ends of the keys, it will deflect or cam the keys laterally to the parallel axially extending full line positions of FIG. 16. The diameter of outer cylinder surface 45 of element 44 should be such as to maintain the keys in this described directly axially projecting position when element 44 is in its FIG. 16 installing position.

At its axially outer end, element 44 carries a transverse diametrical pin 46', whose opposite ends project into parallel axial slots 47 formed in the cylindrical side wall 48 of a driving element 49, the latter having a transverse axially outer end surface 50 to be engaged by a hammer or other driving tool at the time of actuation of the keys to their locking positions. A coil spring 51 may normally urge element 49 axially outwardly to its FIG. 16 position relative to element 44. The annular axially inner transverse end surface 51 of portion 48 of element 49 is ofa diameter to engage the axially outer ends of the two keys in their FIG. 16 full line positions, so that when element 49 is driven downwardly or axially inwardly it functions to drive the keys to their broken line locking positions of FIG. 11.

In installing an insert of the FIG. 11 type with the tool of FIG. 16, the first step is to screw the insert to its FIG. 16 position within the carrier part, with the outwardly projecting ends of the keys being helpful in turning the insert to that position. Next, a user moves tool 43 axially inwardly to the FIG. 16 position, so that camming surface 46 engages the angular keys and deflects their outwardly projecting ends laterally and apart to the full line positions of FIG. 16, following which element 49 is driven axially inwardly relative to element 44 to drive the keys to their locking positions.

In all of the discussed forms of the invention, it will of course be apparent that the key retaining grooves may if While I have typically described certain specific embodiments of my invention, it is of course to be understood that the invention is not limited to these particular forms, but rather is applicable broadly to numerous variations falling within the scope of the appended claims.

lclaim:

1. A fastener assembly comprising a body having a thread which is disposed about an axis and is adapted to be connected to a coacting part, said body containing a generally axially extending groove, a key received at least partially within said groove and adapted to be driven generally axially therein to a locking position, said groove being shaped to direct said key along a path which advances radially toward the material of said coacting part as the key advances generally axially, in a relation deforming said material of the coacting part by said key and thereby locking said thread against detachment from the coacting part, said groove having a portion of undercut cross section containing andretaining a portion of said key, said groove having a second portion axially inwardly beyond said first mentioned portion which is of non-undercut cross section until the key is driven axially.

2. A fastener assembly comprising a body having an external thread which is disposed about an axis and is adapted to be screwed into an internal thread in a carrier part, and having an additional thread to be connected to another member to secure the latter to the carrier part through the medium of said body, said body containing a groove extending generally axially through and interrupting at least a portion of said external thread, a key received at least partially within said groove and adapted to be driven generally axially therein to a locking position, said key having a portion positioned in the groove deep enough to advance within the interior of said internal thread in the carrier part without substantial interference therewith, and said groove being shaped to direct said portion of the key radially outwardly into said internal thread of the carrier part as the key is driven generally axially to thereby deform the internal thread and lock said body against detachment from the carrier part, said groove having a first portion of undercut cross section containing said key and retaining it against radial separation from the groove, and having a second portion of non-undercut cross section beyond said first portion of the groove and adapted to be deformed to an undercut cross section by the key as it is driven generally axially.

3. A fastener assembly as recited in claim 2, in which said key has fins at its opposite sides for deforming said groove to said undercut cross section.

4. A fastener assembly as recited in claim 2, in which said key has fins at its opposite sides for deforming said groove to said undercut cross section, said fins having a camming shape tending to urge said key tightly against an inner wall of the groove as the key advances generally axially.

5. A fastener assembly comprising a body having an external thread which is disposed about an axis and is adapted to be screwed into an internal thread in a carrier part, and having an additional thread to be connected to another member to secure the latter to the carrier part through the medium of said body; said body containing a groove extending generally axially through and interrupting at least a portion of said external thread; a key having a first portion tightly retained in fixed position within an undercut portion of said groove, to remain in said fixed position as said body is screwed into a carrier part, and adapted to be driven thereafter generally axially to a locking position; said first portion of the key being carried in the groove at a location deep enough to advance within the interior of said internal thread in the carrier part without substantial interference therewith as said body and the carried key are screwed into the carrier part, said key having a second portion projecting axially outwardly beyond the groove and accessible for driving the key axially inwardly to said locking position after the body and key have been screwed into said carrier part; and said groove being shaped to direct said first portion of the key radially outwardly into said internal thread of the carrier part as the key is driven generally axially to said locking position and in a relation deforming the internal thread and locking said body against detachment from the carrier part, said groove being disposed at an angle to said axis, said first portion of the key received within the groove being disposed at said angle to the axis, and said second portion which projects axially outwardly beyond the groove being disposed substantially parallel to said axis.

6. A fastener assembly comprising a body having an external thread which is disposed about an axis and is adapted to be screwed into an internal thread in a carrier part, and having an additional thread to be connected to another member to secure the latter to the carrier part through the medium of said body; said body containing a groove extending generally axially through and interrupting at least a portion of said external thread; a key having a first portion tightly retained in fixed position within an undercut portion of said groove, to remain in said fixed position as said body is screwed into a carrier part, and adapted to be driven thereafter generally axially to a locking position; said first portion of the key being carried in the groove at a location deep enough to advance within the interior of said internal thread in the carrier part without substantial interference therewith as said body and the carried key are screwed into the carrier part, said key having a second portion projecting axially outwardly beyond the groove and accessible for driving the key axially inwardly to said locking position after the body and key have been screwed into said carrier part; and said groove being shaped to direct said first portion of the key radially outwardly into said internal thread of the carrier part as the key is driven generally axially to said locking position and in a relation deforming the internal thread and locking said body against detachment from the carrier part, said key being shaped to deform the groove from a non-undercut cross section to an undercut cross section as the key is driven generally axially, and having a camming shape tending to urge the key radially against an inner wall of the groove during and as a result of said generally axial movement.

7. A fastener assembly comprising a body having an external thread which is disposed about an axis and is adapted to be screwed into an internal thread in a carrier part, and having an additional thread to be connected to another member to secure the latter to the carrier part through the medium of said body; said body containing a groove extending generally axially through and interrupting at least a portion of said external thread; a key having a first portion tightly retained in fixed position within said groove, to remain in said fixed position as said body is screwed into a carrier part, and adapted to be driven thereafter generally axially to a locking position; said first portion of the key being carried in the groove at a location deep enough to advance within the interior of said internal thread in the carrier part without substantial interference therewith as said body and the carried key are screwed into the carrier part, said key having a second portion projecting axially outwardly beyond the groove and accessible for driving the key axially inwardly to said locking position after the body and key have been screwed into said carrier part; and said groove being shaped to direct said first portion of the key radially outwardly into said internal thread of the carrier part as the key is driven generally axially to said locking position and in a relation deforming the internal thread and locking said body against detachment from the carrier part, said groove having a first portion of undercut cross section containing said key and retaining it against radial separation from the groove, and having a second portion of non-undercut cross section beyond said first portion of the groove and adapted to be deformed to an undercut cross section by the key as it is driven generally axially.

8. A fastener assembly as recited in claim 7, in which said key has fins at its opposite sides for deforming said groove to said undercut cross section, said fins having a camming shape tending to urge said key tightly against an inner wall of the groove as the key advances generally axially.

9. A fastener assembly as recited in claim 7, in which said groove has a radially inner wall against which said key is received and which in advancing axially inwardly first extends substantially directly axially at a location spaced inwardly of the minor diameter of said external thread and then curves smoothly and gradually radially outwardly to deflect the key into said thread of the carrier part.

10. A fastener assembly as recited in claim 7, in which said groove is disposed at an angle to said axis to direct the key at a radially outward angle; said first portion of the key which is retained in fixed position within said groove, being disposed at

Claims

1. A fastener assembly comprising a body having a thread which is disposed about an axis and is adapted to be connected to a coacting part, said body containing a generally axially extending groove, a key received at least partially within said groove and adapted to be driven generally axially therein to a locking position, said groove being shaped to direct said key along a path which advances radially toward the material of said coacting part as the key advances generally axially, in a relation deforming said material of the coacting part by said key and thereby locking said thread against detachment from the coacting part, said groove having a portion of undercut cross section containing and retaining a portion of said key, said groove having a second portion axially inwardly beyond said first mentioned portion which is of non-undercut cross section until the key is driven axially.

10. A fastener assembly as recited in claim 7, in which said groove is disposed at an angle to said axis to direct the key at a radially outward angle; said first portion of the key which is retained in fixed position within said groove, being disposed at said angle to the axis.

11. A fastener assembly as recited in claim 7, in which said groove, in extending axially inwardly, first extends substantially directly axially and then curves to advance radially toward said material of the coacting part, said key being constructed to bend in following said curving groove.

12. A fastener assembly as recited in claim 7, in which said groove is substantially straight and disposed at an angle to said axis.