US 2716226 A
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United States Patent O ELECTRICAL SOLDERLESS CONNECTOR Walter Monroe Jonas, North Bergen, N. J., assigner to Reiner Electronics Co., Inc., a corporation of New York Application June 22, 1951, Serial No. 233,664
1 Claim. (Cl. 339-268) My invention relates to connectors and more specifically to electrical connectors having a readily removable securing means for attaching a conductor therein.
The usual practice in electrically connecting an insulated conductor to a tubular sleeve is to solder the bared end of the conductor to the connector. While such a connection may have good electrical characteristics, the soldering is generally disadvantageous. Quick connection and disconnection without special tools is of great importance especially when required in a military operation in the field, when the use of a soldering iron, a source of heat, and a supply of solder is not available to the repairman.
Accordingly, a principal object of my invention is to provide an electrical connector to which a conductor can be easily assembled to make a satisfactory connection with ordinary tools, such as a screw driver or wrench.
A soldered connection does not provide a strong mechanical connection nor one with high pull-out values. Moreover, a soldered connection can only be tested by a longitudinal pull which may weaken the connection and cause a latent defect.
Connectors having various forms of positive securing means have been heretofore designed, but all have disadvantages which make them unacceptable.
For example, there is the type of connector in which a small length of the bared end of a conductor is engaged by the end of a securing screw. ln this type the electrical as well as mechanical characteristics are inferior for only a small area of contact is possible causing the conductor to be weakened and easily parted.
Another important purpose of my invention therefore, is to provide a maximum area of pressure contact of the conductor with the connector to increase the mechanical pull-out value and simultaneously increase the area of contact for the electrical connection.
While a sinple wedge type connector provides a large area of electrical contact it is not desirable as the connection is not readily reusable. Separation requires substantial destruction of the wedge type connector, especially where the connectors are small in size. Furthermore the wedges work loose in the connector when vibrated, and tension on the wire causes the connector parts to separate. Connectors of this type, as well as connectors that use transverse clamping members are excessive in width vfor use as leads for meters, test devices, and in confined installations.
Therefore another object of my invention is to provide a securing means that is longitudinally aligned with its housing to reduce the overall thickness of the connector.
Other objects of my invention are to provide a connector having maximum pull-out values; to provide an area of electrical and mechanical contact that is longer than the length of the securing means; to provide a connector with an undersized screw securing means that will not cut the strands of the conductor; and to provide a connector having a minimum of parts that can be manu- 2,716,226 Patented Aug. 23, 1955 factured inexpensively and by mass production methods, I accomplish these and other objects and obtain my new results as will be apparent from the device described in the following specification, particularly pointed out in the claims, and illustrated in the accompanying drawing, in which:
Fig. l is a longitudinal view of my assembled connector used in a test prong attached to an insulated conductor;
Fig. 2 is a longitudinal view of the connection with the handle partially in section, unthreaded from the connector and pushed back over the conductor;
Fig. 3 is an enlarged partial longitudinal sectional View of the connector with some of the parts exploded to show their relationship;
Fig. 4 is a similar view with the parts joined to form the connection;
Fig. 5 is a transverse sectional view taken along line 5-5 in Fig. 4;
Fig. 6 is a modified construction in which the connector is used in a splice type connection; and
Fig. 7 is a transverse sectional View of Fig, 6, after the connection has been made.
In the drawing reference character 10 designates generally a test prong, which illustrates one use for my connector, shown attached to an insulated conductor 12 over which is slidably positioned a tubular handle 14 internally threaded at 16 to engage the test prong 10.
The test prong is constructed of any suitable conducting material, preferably brass, and has at one end a pointed portion 18 and at the opposite end a socket or recessed portion 20. The prong is externally threaded at 22 to receive the threaded end 16 of the handle, and intermediate the two ends a peripheral shoulder 24 is formed to provide a stop for the handle when attached, as shown in Fig. 1.
As shown in Figs. 3 and 4, the bore of the recessed portion may be threaded as at 26 to receive a screw 28 of smaller diameter than the threaded bore, but with the same number of threads per inch as the bore to enable the screw to be threaded in the bore with the bared end 30 of the conductor 12 positioned in between.
To avoid any error in judgment it is advisable to insert the conductor end into the bore until it engages the end wall 31. The screw 2S is then inserted into the space 32 between the conductor and the bore, into the same end of the tubular portion as the bared end 30 of the conductor is inserted, and the screw turned until the corresponding threads engage each other. The end 34 of the recessed portion 20 may be beveled to facilitate the entry of the screw and conversely, the end of the screw may be tapered to accomplish the same result. The greatest wear on the conductor is at the end 34 on which the conductor pivots when moved, and so it is desirable to have this end rounded as well as bevelled.
The threading operation may be continued by engaging the slot 36 in the head 38 with a screw driver or other suitable instrument. This screwing action causes the bared end of the conductor to be compressed in the zig-zag clearance 40 between the threads of the screw and those of the bore respectively, and to assume a corrugated shape conforming to the shape of the clearance. The increased area of contact between the conductor and the threads 26 of the bore through this corrugated shape insures excellent electrical conductivity and a high strength mechanical connection with maximum pull-out value.
If the proper clearance 4U is provided, the bared end 30 of the conductor is bent into a corrugated shape without any cutting action by the threads. The bared end 30 is in eect snubbed in position at each thread it engages in the bore. If the usual multiple strand conductor is used, the twisting action of the screw when being threaded inwardly causes the strands to be spread out fan-like, asA shown in Fig. 5, increasing the electrical and mechanical eciency of the connection.
As a matter of convenience for packaging and shipment, and to prevent loss of. the. connector parts, depending upon the size ofv the conductor toy be` accommodated, the. diameter of the undersized screwv may be madeV suiciently large to -be retained in the tubular portion when slightly canted. so that itl will not, generally fall out. As the screw is preferably longer than meboreV ofthe. tubular portion, theV screw can be completely inserted and tightened in place byl Contact with some of the threads.
A predetermined amount of exposedwire, designated as 41 in Fig. 4, is allowed to remain between the-end: of. the insulation and the head 381 ofthe screw 28. This construction permits theaxial alignment ofY the; connected insulated wire, the screw, and test. prongs as shownin- Fig; 2, within the. attached handle as a completed assembly, as shown in Fig. 1. The head 38 of the screw is less inv diameter than. the bore. of the handle 14 toffacilitate the entry of the finished connection into thehandle.
In Fig. 6 I` have illustrated the usev of my invention in an in-line splice type of connector in which the recessed.
portion maybe a sleeve: 4Z open at, each end to receive oppositely positioned bared ends 44.y and 46: of the respective insulated conductors 5t)l and 48 to4 be joined. The bore ofthe sleeve 42 is threadedto receive an undersized screw 52 in the manner'previously'describedinconnectionwith Figs. l to 5. When the screwS'Z isthreaded to the sleeve, the enclosed strands of; the bared ends of the wires. areV attened and intermingled as shown. in Fig. 7 to provide. an excellent' electrical and mechanical connection. Tov assist in making the connection the baredends'. 441.y and 46 of the conductorsmay be. extended entirely through the sleeve and laterally' around the openv ends of the. sleeve to besnubbed thereagainst; when the screw 52 isr applied. Thereafter, the. loose wire ends-v may be cut o and the connection taped or otherwise` provided with aninsulation cover.
Where the conductors to be spliced' extend' from the. same directiom. the recessed portion may heconstructed inthe ommof a socket, similar to the construction-illus.- trated in Figs. 3 and 4, and both baredends ofthef conductorsnserted in the mouth ofthe socket.
Byiprovidingan undersized screw for' longitudinal engagement within any internally threaded recessed. portion! as a; means tov securetherein a bared end ofA the conductor, I can obtain an electrical engagement with the,` recessed portion, substantially along the length of the bared end,
and'v simultaneously obtain a superior mechanical cong nection. The conductor isclamped between the threaded parts of; the connector giving an improved c onnectiom I am able to reduce the. width of the-connector which is,k
eliminating the need for a soldering iron andisolder, and.
4 increasing the universal use of my connector. The connection is readily reusable eliminating the need for spare parts. The connector can be inexpensively machined resulting in a reduced cost o manufacture.
My novel connector can be used in an in-line splice connector in which case the recessed portion is open at both ends, or it may be used to secure a plurality of conductorsi'n asocket type of connector.
IA have thus described my invention, out I desire it understood'A that it is not confined to the particularY forms or uses shown and described, the same being merely illustrative, and that the invention may be carried out in other ways without departingfrom the spirit of my invention, and, therefore, I claim broadly the right to employ all equivalent instrumentalities coming within the scope of the appended claim, and by means of which, objects of my invention are attained and new results accomplished, as it is obvious. that the particular embodiments herein shown and described are only some ofi the many that can be employedr to attain these objects and accomplish these results.
An electrical connection easily connected and disconnected without damage to. the wire comprising a wire, a body member having a threaded recessed portion with uniform diameter larger than the diameter of the wire,
and' a threaded securing member positioned in said re-A cessed portion and having a uniform diameter smaller than the threaded recessed portion of the bodyv member, and engaging one side of said threaded recessed portion, said wire having a. cross-sectional area less than the` difference between the cross-sectional area.k of the threaded.
recessed portion and the cross-sectional area of the threaded securing member and being compressedbetween the body member and the threaded securing member and containing two sets ofV threads, one which engages and matches the threads of the recessed portion of the body.
References Cited in the tile of. this patent UNITED STATES PATENTS 1,298,879 Brown Apr. l, 1919l 1,596,673 McLaughlin Aug. 17, l-926 1,709,393 Fitch Apr. 16, 1929il,813,16-'/ Kaisling- July 7, 193-1 1,836,480 Loughridge Dec. l5, 1931" 1,982,212 Hagist. Nov. 27, 1934 2,175,871 Bourne Oct. 1-0, 1939- 2,456,601 Weisberg Dec, I4, 1948` FOREIGN PATENTS 807,750 France Oct. 26, 1936y