US2842023A - Sheet metal staple with inwardly lanced wire securing tabs - Google Patents

Description

July 8, 1958 J. v. MAJEWSKI SHEET METAL STAPLE. WITH INWARDLY LANCED WIRE SECURING TABS Filed March 16, 1955 INVENTOR. c/TO/Zfl Z/.' Maz/ews/(c' BY firtorney 2,842,023 Patented July 8, 1958 ice SHEET METAL STAPLE WITH INWARDLY LANCED WIRE SECURING TABS John V. Majewski, It iilwaukee, Wis, assignor to Me- Graw-Edison'Company, a corporation of Delaware Application March 16, 1955, Serial No. 494,648

3 Claims. (Cl. 85-49) The present invention relates to wire fasteners, and

particularly relates to fasteners for attaching conductors,

such as ground wires and other electrical conductors, to wood poles and other supporting structures in a manner that will provide secure electrical engagement with the conductor while the conductor is secured to the supporting structure, and further which fastener will maintain such engagement therewith, even if the fastener should later become loosened from the structure, thereby preventingradio or television interference which might result from an insecure connection between the fastener and the conductor.

this reception was the problem of insecure mechanical connections to hardware and other conducting materials used on distribution and transmission lines. Devices such as lock washers and other retaining means have aided considerably in securing connections to hardware and other devices requiring connections.

In many instances the grounding connection to electrical instrumentalities, has itself, been the cause of radio and television interference problems, especially where the ground conductor has been insecurely fastened to the clamping means or insecurely fastened to a wood pole or other supporting structure. The interference problem is especially noticeable where staples, fasteners, or other attaching devices have eventually loosened after a period of years of insertion in the wood poles.

It has been the practice in the past to provide an inexpensive staple for ground wires and the like, which freely embraced the conductor, and was secured to the wood in the usual practice by using tapered driving points. However, it is well-known that, due to atmospheric conditions, supporting wood structures became checked, dried out, or otherwise permitted the staple to become less securely fastened thereto. This provided a relatively loose connection with the conductor, permitting it to be free to vibrate relative to he fasening device. This vibration caused interference with the normal reception of radio or television receivers.

It is a primary object of the present invention to provide a wire fastener, which may be manufactured from sheet material, and which is readily and inexpensively formed to provide secure attachment to the wire per se, along with the provision of secure embedment in a wood pole or other supporting structure.

It is another object of the present invention to provide a wire fastener having a resilient tab member providing a locking means for securing the fastener directly to a wire, and which fastener may be further driven into a supporting structure for securing the wire to that structure.

It is a further object of the present invention to provide a wire fastener having bifurcated pointed leg por- 2 tions, for attachment to a supporting structure and including opposed resilient tab members coopeiating with a bight portion joining said leg portions to secure said wire thereto independently of the attachment of said leg portions with said supporting structure.

It is still another object of the present invention to provide a Wire fastener which may take the form of one or more embodiments derived from a single stamping, which stamping has been pierced, slit and lancedin a single configuration acceptable for said embodiments.

Referring now to the drawing:

Fig. 1 is an isometric view of one embodiment of the wire fastener illustrating the fastener as it appears when it has a conductor associated therewith.

Fig. 2 is an isometric view, similar to the View of Fig. 1, but directed to another embodiment of the wire fastener.

Fig. 3 is an elevational view illustrating a stamped, pierced, slitted and lanced blank utilized for forming either of the embodiments of Figs. 1 and 2.

Fig. '4 is an elevational view of the embodiment of Fig. 1.

Fig. 5 is an elevational view of the embodiment of Fig. 2.

Fig. 6 is a fragmentary view taken along the line 6-6 of Fig. 5 illustrating the fastener before inserting a conductor therein.

Fig. 7 is a fragmentary .view similar to Fig. 6, but illustrates the operation of the device and having a conductor associated therewith.

.Referring now to the embodiment of Figs. 1 and 4, it will be apparent that the fastener is of a generallshaped configuration. The various operating portions of the present fastener embodiment will now be described in connection with its manufacturer. That is, with reference to Fig. 3, the article is first blanked from sheet metal stock to take the form generally designated by the reference numeral 1. The next operation is a piercing operation, and provides the opening 2 for receiving the wire or conductor, as will be hereinafter described. The blank is preferably tapered at one end so as to facilitate the operation of driving the fastener into a pole or other structure (not shown).

Either simultaneously with the piercing operation, or as the next step, the blank 1 is preferably slit substantially at its center line to provide the slot 3 joining'the opening 2 and the tapered end defining the drive points 4. The tabs 5 and 6, and the spurs 7 and 8 are next outlined by means of a lancing operation.

For the Z-shaped embodiment of Figs. 1 and 4, the blank 1 illustrated in Fig. 3 is preferably subjected to two forming operations, the first of which bends the bifurcated leg portions liiand 11 away from oneanotherin opposed spaced-apart relationship. A second forming operation is preferable, and exerts compressive forces against the lateral edges thereof to slightly superimpose the portions 10 and 11 relative to one another as shown in Fig. 4. The outer surface 12 of the portion intermediate the leg portions 10 and 11 completes the driving surface for receiving hammer blows as will later be described.

Additional auxiliary forming operations are also necessary to bend the spurs 7 and 8 outwardly relative to one another as shown in Figs. 1 and 4 and also to bend the tabs 5 and 6 inwardly relative to one another. It is to be noted that the tabs 5 and 6 are preferably in substantial alignment relative to one another, and that tab 5 is relatively shorter than the tab 6.

The Z-shaped embodiment of Figs. 1 and 4 operates as follows: The conductor C is inserted between the bifurcated portions 10 and 11 and the tapered or pointed ends 4 of these portions are placed in the desired mounting position relative to the wood pole or other supporting a U structure. Hammer blows are then imparted to the driving surface 12 of the fastener. The fastener is then driven into the supporting structure. It willbe apparent that since the spurs 7 and 8 are preferably bent outwardly opposed relative to one another, the driving action tends toforce the legs inwardly relative to one another by means of a simple camming action as they are being driven home. This action is advantageous, but it will be apparent that the spurs may be bent in either direction if so desired, and are primarily provided to prevent outward displacement of the fastener when it has been driven into the support. As the fastener is being driven into the support, the inwardly bent, shorter tab will be urged in a direction towards alignment with the leg portion by the conductor C, but after the widest cross sectional portion of the conductor passes the free edge of relative ly short tab 5, the biased tab will cam inwardly to engage the surface of the wire or conductor C below its greatest dimension to act as a wedge, or snap-lock to prevent withdrawal of the conductor away from the bight surface portion 15. The longer tab 6 is resiliently urged laterally against the conductor to complete the secure engagement of the conductor with the fastener.

It will be apparent should the fastener later become loosened from the support, despite the secure engagement provided by the spurs 7 and 8, it will remain securely fastened to the wire or conductor C by means of the concurrent locking action provided by the tabs 5 and 6 and the bight surface of the fastener.

It will also be apparent that, although both tab members 5 and 6 are preferred, it is within the province of this invention to provide a single resilient tab member having a free edge spaced from the bight portion 15 which will act as a locking wedge for securing a wire or conductor therebetween.

The spurs may also take any of various forms, including notches at the edges of the bifurcated legs (not shown) if so desired.

Referring now to the embodiment of Figs. 2, 5, 6 and 7, it will be seen from Fig. 2 that the fastener has a general U-shaped configuration to provide the leg portions 10, 11 and their intermediate bight portion 20.

In the following discussion it is to be noted that like parts of both embodiments are represented by the same reference characters. 1

Again, the present U-shaped embodiment is manufactured from the blank 1 of Fig. 3. Identical operations including blanking, piercing, slitting and lancing are performed on the blank to provide the configuration shown in Fig. 3. This blank is then formed with a reverse bend to provide the U-shaped configuration. The spurs 7 and 8 are again preferably formed to project outwardly relative to one another as shown in Fig. 2. It is to be observed that since the portions 10 and 11 are formed as with the double bifurcation, the spur '7 on the portion 10 will be bent oppositely from the originally disclosed Z-shaped embodiment of Fig. 1. This is also true of the conductor retaining tab 5, which is bent inwardly with relation to the tab 6 to provide a locking means for holding the conductor in secure engagement tightly against the surface 15 of the bight portion 20.

As illustrated in Figs. 2, 6 and 7, the U-shaped embodiment operates substantially identical to that of the Z-shaped embodiment. That is, the conductor or wire C is inserted between the bifurcated leg portions 10 and 11 and thefastener is driven into the wood pole or other support by repeated hammer blows applied to the outer driving surface. The spurs 7 and 8 act somewhat as a cam surface to aid the points or tapered portions 3 to be directed towards one another. The conductor C is then forced beyond its major cross sectional dimension to pass the shorter tab 5 and be locked in place relative thereto aided by the spring action of the tab 6 bearing transverseiy against peripheral surface of the conductor.

It will be apparent that a wire fastener has been provided from the fiat metal stamping that is of improved construction and arrangement and which securely engages itself to the conductor, and is held in such engagement, even though the attaching legs may eventually become loosened from the supporting structure.

I claim:

1. A fastener formed from a sheet metal blank and adapted to be driven into a support for securing an electric wire thereto and comprising a member having opposed planar leg portions joined by a transverse portion, said transverse portion jointly providing a driving surface and a bight surface engageable with said wire, opposed rcsilient tongue-like tabs lanced inwardly of each of said leg portions, said tabs being of relatively different lengths and each having a free end extending towards said bight portion, the free end of the relatively shorter tab being spaced from said bight portion a sufficient distance to permit sliding engagement with said wire in a direction eX- tending longitudinally of the legs and towards said bight portion and to further oppose movement of said wire in an opposite direction, the relatively longer of said resilient tabs being biased inwardly of the leg portions and being arranged to press said wire against the opposite leg portion, whereby said tabs are arranged to maintain electrical engagement of said fastener with said wire.

2. The fastener of claim 1 wherein said planar leg portions and said transverse portion jointly define a Z-like configuration transversely of said leg portions.

3. The fastener of claim 1 wherein said planar leg portions and said transverse portion jointly define a U-like configuration transversely of said leg portions.

References Cited in the file of this patent UNITED STATES PATENTS 172,753 Lindsey Ian. 25, 1876 1,072,974 Moore Sept. 9, 1913 1,087,264 Sheppard Feb. 17, 1914 FOREIGN PATENTS 11,065 Great Britain July 17, 1913 470,821 Canada Jan. 16, 1951

Images