US2890734A - Wire locked bolt assemblies - Google Patents

Description

June 16, 1959 J. F. MULLlN 2,890,734

WIRE LOCKED BOLT ASSEMBLIES Filed Aug. 2, 1956 INVENTOR If m WWW x fi 5 BYWIW United States Patent flice 2,890,734 Patented June 16, 1959 WIRE LOCKED BOLT ASSEMBLIES John F. Mullin, Hollywood, Calif. Application August 2, 1956, Serial No. 601,794

4 Claims. (Cl. 151-33) This invention relates to wire locked bolt assemblies and aims generally to improve the same, and to provide improved methods and means for the production thereof. The present application is in part a continuation of my copending application Ser. No. 428,906, filed May 11, 1954, and now abandoned.

Among the objects of the invention, severally and interdependently, are the provision of a novel locked bolt assembly providing a more secure fastening with smaller and lighter parts than those previously provided; one in which the bolts may be further tightened, or retightened in the normal manner, even after being wire locked; one in which the wiring does not and cannot obstruct the path of engagement of the tightening tool with the bolts; one in which the tightening of one or more of the bolts after wiring does not produce slacking off or shearing otf of the lock wiring or change its association with the bolts to a non-locking association; one in which the bolts include novel features facilitating the wiring thereof; one in which the bolts are wired with two standing parts of wire one of which passes through and the other of which passes around each bolt of the assembly, the wires being twisted or otherwise interassociated between bolts and beyond each end bolt of the wire locked series; one in which the dual wiring just mentioned is associated in such manner that the wires, interassociated between the bolts, flare apart at the bolt heads so as to support each other adjacent the bolts in the plane of rotation of the bolt head reducing tendency of the wire to break by sharp bending on rotation of a wired bolt head; one in which, if a bolt is tightened after wiring, the twisted wire portions between bolts may be subsequently bent to relieve elastic tension of the wires and dissipates forces that would otherwise act in a direction tending to loosen the bolt; to provide a bolt element for such wire locked assemblies particularly adapted to the production of one or more of the foregoing objects; to provide a bolt element for wire locked assembly arranged to facilitate the wiring thereof; to provide a novel method of wire locki-ng such bolts; and to provide other and further novel features and. combinations of features contributing to the realization of objects hereinbefore stated.

. The invention resides in the novel features and com-,

binations herein disclosed and is more particularly pointed out in the appended claims.

In the accompanying drawings of exemplary embodiments of the invention:

Fig. 1 is a perspective view of a lock bolt assembly.

Fig. 2 is a section on the line 2-2 of Fig. 1 to an enlarged scale.

Fig. 3 is a perspective view of the bolt structure employed in forming the assembly of Fig. 1.

Fig. 4 is a vertical section taken on the line 44 of Fig. 3.

Fig. 5 is a view similar to that of Fig. 2, but of a modified arrangement.

Fig. 6 is an elevational detail of a modification of the bolt of Fig. 3.

Fig. 7 is an elevational detail of another modification.

Fig. 8 is a vertical cross section taken on the line 88 of Fig. 7.

Fig. 9 is a horizontal cross section taken on line 9-9 of Fig. 8.

In the illustrative embodiments shown to exemplify the invention the reference numerals 10 and 11 designate a pair of superimposed abutting plates or members fastened together by an improved wire locked bolt assembly in accordance with the present invention.

As clearly shown in Figs. 3 and 4 the bolts employed in said assembly each include a threaded shank 15 with a head 12 on one end of such shank, a perforation 13 extending through said head 12 transversely of the shank axis, a peripheral groove 14 connecting the ends of said perforations 13, and tool engageable means 16 separate from and above said groove and perforation. In this illustrative embodiment the bolt or machine screw 12-15 is provided with a fillester head 12 with the perforation 13 extending diametrically through the cylindrical portion of the fillester head below and in spaced relation to the .tool engageable means shown as a kerf 16 engageable by a screw driver, but the invention in its broader aspects is not limited to such forms.

Still referring particularly to Figs. 3 and 4, the periph eral groove 14 in the form shown extends circumferentially about the cylindrical head 12 at the same'level as the perforation 13 and hence affords two peripheral grooves connecting the opposite ends of such perforation. As shown the perforation 13 has a diameter greater than the width of the groove 14, thus actually dividing the circumferential groove 14 into two peripheral grooves entering the ends of the perforation from opposite sides. This construction is particularly advantageous as it greatly facilitates and expedites the wiring of the bolts in forming the wire locked assembly, as hereinafter explained.

Furthermore, as is best shown in Figs. 2 and 5, the peripheral groove 14 laterally connecting the ends of the perforation 13 is preferably about semi-circular in cross section and of a diameter somewhat larger than the diameter of the wire 17a, 17b, to be used to form the assembly, and the perforation 13, as above noted, is of a still larger diameter relative to the wire. With this form of the invention the ends of the perforation 13 need not be .chamfered, or may be chamfered only slightly, to less than the depths of the groove 14, to afford a larger external indication of the point of intersection of the perforation 13 and the circumferential groove 14, as illustrated at 13a in Fig. 6. 1

The forms shown in Figs. l6 in which the perforation 13 is wider than the groove 14 and considerably Wider than the individual wires to be employed, is especially desirable for small bolts and machine screws in the size ranges ordinarily driven by a screw driver of the flat blade or of the Phillips type, and the clearance between the Wire and the perforation in such form enables the Wire to bend at the ends ofthe perforation, when necessary, on a relatively large radius as shown in Figs. 2

- and 5, rather than sharply. In the form shown in Figs.

113 and the groove 114 so that a wire rather closely fitting the aperture proper may be bent at the end thereof on a relatively gentle radius.

The method of producing the improved wire locked assembly of Figs. 1 and 2 employing the headed bolts according to Figs. 3 and 4 or 6, comprises the steps of 52: assembling a series of the bolts 12 with the parts 10, 11 to be secured thereby, passing a standing part 17a of the wire 17 through the perforation 13 of one of the bolts 12 and another standing part 17b (shown attached to the first standing part, asby twisting at 170) about the head 7 of the bolt in the associated groove is and twisting the two standing parts together for a sufficient distance to reach the next bolt of the series, passing one of the wires through the perforation and the other about the peripheral groove of said next bolt of the series to bring its previously twisted portion close up to said next bolt and again twisting said wires together beyond said next bolt for a distance sufficient to reach the succeeding bolt, and repeating the operation until the last of the series of bolts has been so wired with the terminal ends of the series secured together as by twisting beyond said last bolt.

The method as just described may be practiced with all the bolts tightened to the maximum or final tension contemplated for the assembly, or for convenience, with one or more of the bolts tightened only nearly to final position leaving the perforation therethrough oriented to be easily accessible or to afford a clear path therethrough as might not be the case if the bolt were fully tightened adjacent to some part laterally proximate to the bolt heads. In the latter case after'the wiring of the bolts, the further step may be practiced of engaging. with the tool engaging means 16 of the bolt a tightening tool the same as that used to initially assemble them in the work, and tightening said bolts where necessary after the wiring thereof. As a rule the twisting of the wires between the bolts will afford sutficient freedom to enable the so treated bolt or bolts to be rotated a fraction of a turn to give them their final tension, with or without producing some slip and tightening of the twisted strands. When necessary, because the strands are twisted together, if it is thought that the portion between the two bolts has been left in a tensed condition that might tend to improperly stress the bolts, or if it is desired to displace the twisted portion between bolts to afford access to an underlying area, the twisted portions between the bolts can be bent between them to exceed the elastic limit of the wire, thus curving the twisted strands out of a direct line from one bolt to the next and relieving any tension therein. Since the twisting of the wires, one of which passes through the bolt, locks the wires to the bolts regardless of whether the intervening twisted portions are tensed or not, this mode of displacing the wires and relieving tension therefrom is practicable, whereas with single wire looks as known to the prior art this would not be the case, as such loosening would therewith reduce the locking action, or even cause the wires to become disengaged in some instances.

As above noted, in the form shown in Figs. 1 and 2, the two standing parts of the wire in advance of the first bolt of the series may be attached to each other by twisting as at 17c. This association can also be effected as shown in Fig. 5, in which the two standing parts are afforded by bending a single wire to provide two standing parts integrally connected in advance of the first bolt of the series.

Also, while one-way twisting as in Figs. 1 and 2 is presently preferred, the invention contemplates an arrangement in which the wires may be associated with the perforations and the grooves or channels of two or more bolts and be then twisted between them either before or after the final tightening thereof. In such case a U-shaped twisting head rotatable in a cage open at its bottom, may be snugly engaged with the two wires at a point intermediate the bolts and then-be operated to twist the central porions 17d of the wires turnbucklewise to'impart right hand and left hand twists to the wires at each side of such central portion as shown in Fig. 5. If the wires are slidable relative to the bolt at one end of the portion being twisted in this fashion, the tool may initially engage them close to that bolt and as it twists the wires back to the bolt through which they are not slidable, it will automatically pull back the wires by the proper amount to afford such degree of slackness or tightness as may be predetermined by the initial positioning of the tool, which may be used for twisting the terminal ends of the wires together after the wiring between the respective bolts has been twisted.

As is also shown in Fig. 5, the bolts of a series of bolts, here shown of low hex-headed form, need not be arranged all in a common plane. In such low hex-headed form especially where only one perforation is provided, the perforations and peripheral grooves are preferably arranged fairly close to the bottoms of the hex-heads, to expose sufiicient thereof above the wires to enable final tightening of the bolts after wiring. When two alternately employable perforations 13, 13a crossing each other at right angles and in the same plane are employed, as shown in Fig. 5, it is usually possible to fully tighten all the bolts before wiring and in such case the hex-head need not project very far above the grooves and perforations, and a very fiat assembly can be produced.

In the smaller sized bolts, in particular, the provision of a perforation 13 of a width greater than that of the groove 14 makes it easier to enter the end of a wire into the perforation since such end may merely be drawn along the groove until it falls into the hole. This same advantage is retained in the form of Fig. 6, in which the slight chamfering or stamping of the edges of the hole above and below the groove are principally. effective to make its location more obvious, in circumstances in which it is desired to orient it for convenience or clear passage as above mentioned.

In the form of Figs. 7 to 9 in which the perforation proper is narrower than the groove, the deep chamfering or enlargement of its outer ends makes such ends wider than the groove, and thus also affords means for guiding the wire tip from the groove into the perforation in addition to its other advantages.

By locating the groove 14 to connect the ends of the perforation 13 laterally of the bolt head and at a level below that of the tool engageable tightening means 16 or 116, the wires locked to the bolt head by twisting are prevented from obstructing the path of engagement of the tool employed for tightening the bolts, enabling the postwiring tightening or retightening thereof as above described.

When the tool engageable means is in the form of a kerf 16, the location of such kerf transversely with respect to the orientation of the perforation assures that "in wiring of. the bolts the wirewill be passed through the lateral groove, and not through the kerf where it would obstruct proper engagement of the tool to the full depth of the cut section of metal, as might be done by -a new or careless operator if the kerf were parallel to the perforation.

As will be clear from Figs..2 and 5, the wires at'the ends of the twisted sections flareapart like a V in the plane of rotation of the bolt head as one of them passes to the grooveand the other enters the perforation chordal to the groove. These flaring wires thus support each other, in the plane'of rotation of. the bolt head, and tend to prevent post-wiringtightening or retightening of the bolt from sharply bending'the wires at the, edge of the perforation, since each wire affords a curved surface across which the other may bend, and since flexure thereof occurs in an extendedlength of wire between the hole and the twisted portion, thus guarding against fatigue and failure of the wire.

Furthermore, the employment of two twisted wires in the manner hereindescribed affords an adequately stiff, but bendable and slightly extensible,.connection between bolts that is superior to that obtainable with a single heavier wire and enables smaller andlighter parts to be employed without sacrifice of locking security. Finally,

the twisting of the wires that pass respectively through the groove and perforation eliminates any slippage of loops over the bolt heads, affords a neat appearance and one that at a glance shows that the wiring has been properly applied, thus keeping inspection rejections at a minimum.

While there have been described herein what are at present considered preferred embodiments of the invention, it will be obvious to those skilled in the art that many modifications and changes may be made therein without departing from the essence of the invention. It is therefore to be understood that the exemplary embodiments are illustrative and not restrictive of the invention, the scope of which is defined in the appended claims, and that all modifications that come within the meaning and range of equivalency of the claims are intended to be included therein.

I claim:

1. A lock bolt assembly comprising a series of headed bolts having shanks engaging in the work to be secured, the several bolts of said series having their heads lying on the same side of the work, each bolt head having a peripheral groove thereabout and having a diametrical perforation chordal of and in the plane of said groove, said perforation having its end flared to a greater diameter than said groove to readily receive a wire tip guided thereto by said groove, at least the bottom of said groove being substantially circular around said head and rounded in cross section, each bolt head having a tool engaging configuration above said groove and perforation, a single pair of twisted wires associated with said series of headed bolts, said wires being twisted together between adjacent bolt heads and one wire of said pair at each bolt head passing through the perforation thereof and the other wire of the pair at each bolt head passing around the bolt head in the said peripheral groove, the pair of twisted wires being thus anchored to the several bolts and being retained from loosening from the bolts and from obstructing the tool engaging configurations of the bolts, said twisted wires sharing the stress of turning of the bolts and sharing and distributing over the flared wire area between the bolt heads and the twisted portions thereof any strain of turning or retightening of the bolts after the wiring thereof.

2. A lock bolt assembly of claim 1 in which the tool engaging configuration above the groove and perforation of each bolt head consists of a kerf extending across said head in a direction transverse to the direction of said perforation.

3. A lock bolt assembly of claim 1 in which the tool engaging configuration above the groove and perforation of each bolt head is of non-circular cross-section.

4. A lock bolt assembly of claim 1 in which the tool engaging configuration above the groove and perforation of each bolt head is of hexagonal cross-section.

References Cited in the file of this patent UNITED STATES PATENTS 484,616 Smith Oct. 18, 1892 497,963 Johnson May 23, 1893 1,104,681 'Lee July 21, 1914 FOREIGN PATENTS 733,821 Germany Apr. 3, 1943

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