US 2160694 A
Description (OCR text may contain errors)
M y 1939- s. N.,BUCHANAN v 5 WIRE CONNECTOR I Filed July 9, i956 2 Sheets-Sheet 1 /////4 7 :ESQ 8 I l o g '2 1 t v INVENTOR.
STEPHEN ATTORNEYS May 30, 1939- s. N. BUCHANAN 5 WIRE cbmmcwoR Filed July 9. 1936 2 Sheets-Sheet 2 "FIG.6
STEPHEN N. BU
Patented May 30, 1939 UNITED STATES PATENT OFFICE The Thomas & Betta 00., Elila both, N. 1.,
a corporation of New Jersey Applicationluly 9, 1936, Serial No. 89,692
The invention relates to a solderless wire connector which provides a contractile wire gripping or clamping means and a cooperating connector member or sleeve which is forcibly moved axially thereon so that the contractile clamping means is contracted and grips a wire therein solely through the contraction thereof. This wire connector'requires no solder and retaim the parts together so that they are not vibrated loose and obtains electrical connection solely through the gripping of the wire whenthe contractile clamping member contracts thereupon. Two forms of solderless wire connectors are illustrated and described herein. The first form of wire connector Figures 1 through 5 show one form of the wire connector. g
Figure 1 is a view in. longitudinal section showing a solderless -wire connector of the invention being assembled with a pair of pliers, which conhector is adapted to secure the ends of two wires together. Such a solderless wire connector is shown-in position preparatory to gripping a wire therein and in position in the jaws of'the pliers preparatory to' forcibly moving the operating sleeve or bushing over the contractile fingers to I contract the latter upon a-wire. a
Figure 2 shows an end view of the pliers and the wire connector in front elevation preparatory to clamping a wire therein. I I Figure 3 is an exploded'view, partially in section, of the wire connector.
upon the center cylindrical portion of the wire connector and with the flexible fingers at'the end thereof expanded preparatoryto receiving the end of-a wire, in which spread position the Figure 4 is an assembled view of the connector of Figures 1 and 2 with slidable bushings-retained solderless wire connector which differs somewhat from that shown in Figures 1 through 5.
Figure 6 is a plan view of a double ended wire connector, with one end of the wire connector in section, showingthe initial steps in the manufacture of the wire connector of this other form.
Figure '7 is a plan view of the finished wire connector with one end thereof in section in order to more clearly show the-construction. The wire connector in this figure is ready to receive a wire to be clamped therein.
Figure 8 is a plan view of the wire connector, with one end thereof in section, showing the connector gripping a wire therein.
Solderless wire connectors are rapidly being 15 adopted,- particularly in maritime trade, for the three important reasons which will now be given. The first reason is that generally the space within which wire connections can be made on board ship is very limited, and a solder-less connection 2 of the type shown herein takes up considerably less space than the equivalent soldered connec tion, or the equivalent solderless connection u'tilizing screw threads on an operating nut or means to obtain the clamping action. The second rea- 25 son is the greater speed with which a solderless connection can be made with the tool or pliers used with connectors of the invention. The third reason is in case of fire there is no danger of the connection being broken as in a soldered con- 30 nection where the solder melts at a comparatively ,low temperature which permits the wire to be pulled free or separated from its connection.-
. The wire. connector shown in Figures 1 through 5 is a double ended wire connector adapted to grip the end of two in order to couple them together: The wire connector has a body member It which is shown as being a single integral member, although it is not necessary-that this part be integral. The body member has initially a uniform diameter or-dimension throughout its lengthand is preferably made from baror rod iii a stock. Each end of the body or clamping member li has a plurality of flexiblefingers or contractile means II. The contractile means or fingers H are formed preferablyby first drilling a bore l2 in each end ofthe clamping member, which bore is smaller than the wire to'be receiired therein. The bore forms awire passasea 5o The bore l2 preferably is provided with serrations i3 formed by threading thebore, which serrations bite into the wire in order to establish good electrical contact therewith and also to more firmly grip the wire therein. The serrations may as be of any form, but screw threading of the bore is the simplest way to provide them.
A plurality of longitudinal or axial slots l4 extend inwardly from each end of the clamping or body member in order to provide the contractile means or fingers II. The contractile fingers or means are thereafter spread apart, as will appear more fully hereinafter, so that the wire receiving bore I2 is enlarged and a wire having adiameter greater than the diameter of the bore I! may be inserted therein. The arms are also spread so that a tapering outer surface is provided upon each contractile finger. Contraction of the fingers causes the latter to grip a wire which has been inserted within the bore. Since the bar is of uniform diameter and the bore I2 is made by drilling, the fingers II have a uniform thickness throughout their length.
An operating means, such as acontrac'ting sleeve or bushing H, has a bore l8 therethrough so that the bushing may be received upon the body or clamping member ID and is slidable thereupon. One end of the bore 3 is rounded at l9. Two such contracting or operating bushings are slipped onto the body member ID so that the rounded end I! of the bore of eachbushing faces towards its respective end of the body member. The contractile means or fingers H are then spread apart for the double purpose of enabling a wire having a diameter greater than that of the wire receiving bore I! to be received therein and for inseparably retaining the bushings assembled upon the body or body member.
In order to render the contractile fingers ll morev flexible and render slotting more easily performed, holes 20 may be drilled through the body member ill at a point spaced from the; end thereof. The slots ll extend to these holes.
Thetwo ends of the body member may carry a counterbore 23, if desired, which receives the insulation of the wire W and thereby provides a neater appearing connector.
In securing the end of a wire within the connector, the wire Wis inserted within the tapered bore 12 thereof formed by spreading the fingers II, as shown in Figure 2, and then the wire connector is inserted between the jaws J of the pliers so .that one jaw engages the bushing or operating means I! and the other jaw engages the end of. the fingers ll. Upon pressing the handles of the pliers together, the jaws move together and force the bushing axially relatively to the connector' body or member so that the bushing rides upon the outspread fingers. II and contracts them to grip the wire W. A wire is'shown gripped in the solderless connector'at the lower end of the connector shown in Figure '1. The rounded end I of the "bore." in the bushing II facilitates movement thereof iipon the fingers II and prevents scoring arid cutting between the two parts. when moved relatively to each other in order to grip the wire -W between the .fingers.
The bushing I! in contracting the fingers ll provides a tight fit between the contracting. "fingers and the bushing so that the latter is retained upon the end of the body member. The fact, too, that the wire W is larger than the wire receivingbore I! in the end ofthe body member; makes the fit between the bushing and the body member or fingers a drive fit,
v even though the bushing passed easily over the fingers when initially assembled upon the body The second form of constructionshown in Figurea 6 through 8 is much like that shown in a bore or hole 3| which is smaller than the wire to be inserted in the wire connector. The bore is preferably tapped so that a thread 32 is formed therein. This thread is not intended for use as a screw thread, but merely to provide sharp serrations or cutting teeth for more securely gripping the wire to be clamped therein. The serrations may be dispensed with if desired. The tapping of the hole is. the easiest method of forming these biting teeth and they also can be formed on an automatic or semi-automatic ma-' chine which substantially reduces the manufacturing cost of the wire connectors.
' The blank is then slotted with slots 33 dividing the end of the blank into preferably two fingers 34. This is accomplished by making one slotting cut through each end of the blank. Obviously, more than two fingers are contemplated.
' as desired.
The contracting bushings, which are the same as the bushings II, are then slipped over the end of the blank to the center portion thereof between the ends of the slots 33; The fingers 34 are then spread apart so that the end of the body or body member 30 is tapered or generally conical as shown in Figure 7. -The. spreading apartof the fingers inseparably' retains the bushings upon the connector and also enables a wire to be inserted therein. In this spread apart position of the arms 34, a second and larger drill is passed into the wire receiving bore and the bore is extended beyond the end of the bore 3| formed by the small drill, to form a wire receiving bore 35 which is at least as great as the diameter oi the wire to be received therein. The finished connector is then ready to receive a wire to be clamped therein.
Since the larger drill was used only after the contractile fingers 44 had been spread apart, only the inner end of the bore has been enlarged since the drill obviously cannot enlarge the bore of the fingers after they have been spread apart. The fingers, therefore, retain their original bore throughout a substantial length thereon. and smaller-than the wire to be received therebetween, which diameter is determined with the fingers in contracted position. In other words. the fingers have a uniform thicknessfor a substantial length thereof, or the length thereof not cut by the larger drill. The larger bore 35 is extended farther into the end of the body member Ill than the smaller bore 3|, so that the end of the wire may be projected well into the bore and the fingers when contracted will grip the wire as far from the end'thereot. as possible. This reduces the possibility of shearing the surface of wire under a heavy pull andwithdrawing-the .wire from the connector.- It will also be noted In order to clamp a wire in this connector, the
wlrewisinserted-int'nthebqre-li until the end of the wire engages the end of the bore. The bushing 11 is then forced, such as by the pliers shown in Figures 1 and 2, onto the conical or tapered portion formed by the spread apart contractile fingers so that the fingers are contracted upon the wire. Due to the fact that when the fingers are so contracted the bore at the serrations is smaller than the wire, the serrations on the inner surface of the fingers bite into the surface of the wire to firmly clamp the wire in the wire receiving bore. The serrations also establish good electrical contact with the wire. Because of the contracting of the fingers ,produced by the bushing II, the bushing is also firmly held upon the outside diameter of the end of the body member 30 or the end of the contractile fingers 34, as discussed in connection with the form shown in Figures 1 through 5. The wire connectors described are just as effective in clamping either a stranded wire SW or a solid wire W.
Although the connectors particularly shown and described herein are double ended connectors, it is to be understood that a single ended wire connector is contemplated. In one aspect of the invention, therefore, the spread apart fingers at one end of the wire connector are stop means for preventing the operating bushing from being removed at this end so that when the fingers are spread'apart at the other end, the bushing I! is then inseparably retained upon the connector or body member.
Various modifications will occur to those skilled in the art in the configuration, composition and disposition of the component elements going to make up the invention as a whole, as well as in the selective combination or application of the respective elements, and no limitation is intended by the phraseology of the foregoing description or illustrations in the accompanying drawings. What is claimed is: l 1. 4 wedge-on solderless wire connector comprising a bodymember, a plurality of contractile clamping fingers having a uniform thickness for a substantial. length thereof, the fingers projecting from the end of the body member and at an angle with respect to the surface of the center of the bodymember, the clamping fingers forming a conical wire receiving bore in the end of the body member and terminating at the inner end thereof into a c'ylindricalbore having a diameter'atleast as'great as that of the wire to be received therein, the clamping fingers when contracted forming a cylindrical outer surface and throughout the aforesaid substantial length forming a cylindrical bore having a diameter substantially less than the diameter of wire to be clamped therein, and an operating means carried by and forcible axially on the body member and engaging the angularly projecting fingers to contract the same inwardly to a cylindrical shape and grip a wire in the wire receiving bore formed bore in each end of the body member and when l contracted .forrning a cylindrical outer surface and cylindrical wire receiving bore, the outer surface of the fingers being smooth, the clamping fingers terminating at the inner end thereof into a cylindrical bore having a diameter at least as great as that of the wire to be received therein, the clamping fingers when contracted forming a cylindrical outer surface and throughout the aforesaid substantial length forming a cylindrical bore having a diameter substantially less than i the diameter of wire to be clamped therein, and an operating means for the contractile fingers at each end and carried upon the center of the body member, the inner; surface of the operating means being smooth, each operating means being forcible axially over the angularly projecting fingers at its respective end of the body member to contract the same inwardly to a cylindrical shape and grip a wire in the wire receiving bore formed by the fingers.
STEPHEN N. BUCHANAN.