AU712177B3

AU712177B3 - Improved crimp connector

Info

Publication number: AU712177B3
Application number: AU89429/98A
Authority: AU
Inventors: Michael Instance; Philip Timbrell
Original assignee: Utilux Pty Ltd
Current assignee: Utilux Pty Ltd
Priority date: 1998-10-20
Filing date: 1998-10-20
Publication date: 1999-10-28
Anticipated expiration: 2000-10-28
Also published as: GB2344472A; GB9924737D0

Description

AUSTRALIA

PATENTS ACT 1990

ORIGINAL

COMPLETE SPECIFICATION PETTY PATENT Invention Title: IMPROVED CRIMP CONNECTOR Name of Applicant: UTILUX PTY LIMITED The following statement is a full description of this invention, including the best method of performing it known to me/us: -2- The present invention relates to electrical connectors, and in particular to electrical connectors that are arranged to be crimped to electrical conductors.

Electrical connectors, such as terminal pins (eg. plug pins), socket connectors etc, include a means enabling them to be electrically engaged with an electric conductor, such as a wire conductor. One of the most widely used means is the crimp receptacle. A crimp receptacle is arranged to receive a conductor and to be crimped to the conductor, usually by using some form of crimp tool.

Crimping affects mechanical and electrical connection of the conductor with the crimp receptacle and electrical connector. The crimp receptacle usually forms an integral part of the electrical connector, eg.

terminal pin. For example, the crimp receptacle may extend rearwardly of a forwardly extending terminal pin, plug pin or socket connector.

There are many different forms of crimp receptacle and many different types of crimp.

One popular type is the "bucket" crimp receptacle which consists essentially of a shaped receptacle which receives a wire conductor and which can be crimped by a crimping tool to the wire conductor.

Another type is a "barrel" receptacle which includes a cylinder with one open end for receiving the conductor into the cylinder. A crimping tool can then crimp a portion of the barrel receptacle, eg. by way of an indent crimp, to the wire conductor.

The present invention provides an electrical connector, comprising a crimp receptacle arranged to receive a conductor and to be crimped to the conductor to provide mechanical and electrical engagement between the crimp receptacle and the conductor, the crimp receptacle including walls defining a passageway, the walls also defining an opening via which the conductor can be received into the passageway, a cross-sectional profile of the passage being quadrilateral in shape and the crimp receptacle being formed from a blank of material which is folded over so that sides of the blank meet at one side of the crimp receptacle, the arrangement being such that when a tortuous path type crimp tool is applied to opposing comers of the quadrilateral to force the comers towards each other, the crimp receptacle collapses symmetrically and evenly.

Preferably, the opposing corners are at the top and bottom of the crimp receptacle.

Preferably, the cross-sectional profile of the passageway is substantially diamond shaped.

Preferably, the opposing comers of the quadrilateral are rounded rather than being sharp.

Preferably, the crimp receptacle is provided with complimentary projections which interlock where the sides of the blank meet.

This crimp receptacle is preferably particularly suited to the formation of a "tortuous path" type crimp. In a "tortuous path" type crimp according to the present invention, a crimp tool comprises opposing hammer and anvil members. The anvil member has a slot which is complementary to a projection in the hammer member. The crimp receptacle is placed between the hammer and anvil and they are brought together. A portion of the receptacle is forced into the slot in the anvil by the O:A5pecA3OO 399\300 349\32026.doc 6/09/99 projection in the hammer. The receptacle becomes stepped, forcing the conductor within the receptacle into a "tortuous path" following the stepped form of the deformed receptacle. The conductor is gripped and held within the tortuous path, providing a better crimp. This type of crimp is particularly suitable for relatively hard or rigid conductors.

The preferred diamond shape of the crimp receptacle has the advantage of promoting a controlled, predictable and consistent crushing of the receptacle during the crimp operation. A round receptacle, eg. a barrel receptacle, crushed with a tortuous path type crimp tool might tend to collapse to one side or the other. With the crimp receptacle of the present invention, when opposing corners are forced together by the tortuous path type crimp, the crimp collapses in a symmetrical and even manner.

The provision of the interlocking projections prevents the crimped conductor from slipping out of the receptacle as can happen with a conventional butt seamed crimp receptacle that is not completely closed.

The crimp receptacle of the present invention is particularly suited to use with a single strand-type conductor e.g. a single strand of wire, such as a single strand of Nichrome (Nickel-chrome alloy) wire, and other relatively hard single wire conductors.

Features and advantages of the present invention will become apparent from the following description of an embodiment thereof, by way of example, and with reference to the accompanying drawings, in which: Figure 1 is a perspective view of an electrical connector in accordance with an embodiment of the present invention; Figure 2 is a view from underneath of the connector of Figure 1.

Figure 3 is a side view from one side of the connector Qf Figure 1.

Figure 4 is a view from the top of the electrical connector of Figure 1; Figure 5 is a view from the other side of the connector of Figure 1; Figure 6 is a view from the front of the electrical connector of Figure 1; Figure 7 is a view from the back of the electrical connector of Figure 1.

Figure 8 is a section on line AA of Figure 2; Figure 9 is a schematic view of the crimp receptacle of the electrical connector of Figure 1, having been crimped; Figure 10 is a further perspective view of the electrical connector of Figure 1 illustrating also components of a crimp tool for applying a tortuous path type crimp, and Figure 11 is a perspective view of the connector in accordance with an embodiment of the present invention showing the crimp receptacle in a crimped state.

Referring to the drawings, an electrical connector is illustrated which includes a first forwardly extending portion 1 and a second, rearwardly extending crimp receptacle 2. The crimp receptacle 2 has walls 3 which define and enclose a passageway 4 which is arranged to receive an electrical conductor 5, through an end opening 6.

:\Speci\300. 399X300 349\32026.dc 6/09/99 -4- The connector is formed from a flat blank of conductive material, in this embodiment being of plated brass. The crimp receptacle 2 is formed by folding a portion of the blank over so that two ends 7 and 8 of the portion meet each other. The portion is folded so that the cross sectional profile of the passageway 4 formed by the walls 3 is quadrilateral and in this case is approximately "diamond" shaped as is most clearly seen in Figures 7, 1 and 10. Two opposing corners 2A and 2B of the crimp are arranged substantially at the top and bottom of the crimp receptacle 2. These corners 2A and 2B are the first to make contact with the preferred crimping tool. We note that the comers of the diamond-shape profile are not necessarily sharp, but may be rounded somewhat. Further, the blank is formed with complementary projections 9, 10, 11, 12 which interlock as clearly shown in Figures 1 and 10 when the blank has been folded to form the crimp receptacle 2.

This form of crimp receptacle is particularly suited to formation of a "tortuous" path type crimp. A tortuous path crimp tool in accordance with an embodiment of the present invention is illustrated in Figure 10 and comprises an anvil 14 and a hammer 15. The hammer 15 includes first surface 16 from which extends a projection 17 and the anvil 14 includes a surface 18 within which there is a recess or slot 19. In operation, when making the crimp, the hammer 15 and anvil 14 are brought together, the projection 17 being co-positional with the slot 19, onto the crimp receptacle 2 initially at corners 2A, 2B. This forces the crimp receptacle 2 to take up the profile which is illustrated in Figure 9 being a "stepped" profile or "tortuous" path 20. A diamond-shaped profile of the crimp receptacle 2 promotes a control, predictable and consistent crushing of the receptacle during the crimp operation. As can be seen from figure 11, the crimp receptacle is flattened evenly and forced into a tortuous path without buckling to one side or the other of the crimp. The interlocking projections maintain the integrity of the "open" side of the crimp receptacle 2 and prevent the wire conductor 5 from exiting the receptacle 2.

The electrical connector illustrated in the drawings is a "bat" connector of the type which is used as an electrical connector for electric blankets. This type of crimp 2 is particularly suited for more rigid conductors, such as those used in electric blankets, although it could be used with any other type of conductive wire. Further, the electrical conductor need not be a bat connector of the type illustrated, but could be any other type of connector.

The wire conductor 5 is preferably a single strand of Nichome wire. This is a relatively hard material, which is high resistance and is particularly suited for use in heating elements. The present invention is not limited to crimping this type of wire.

Please note that the crimp receptacle 2 could be used with other types of crimp tools, but it is most suited to the step-type, tortuous path type tool in accordance with the present invention.

Note that the tortuous path may be more complex than shown in the drawings. For example there could be more than one projection on the hammer and more than one complementary slot on the anvil, to create a multiple-stepped tortuous path. Further, two complementary projections are shown on the crimp portion in the illustrated embodiment, but there may be more than two complementary projections.

J:\Speci300. 399\300 34932026.doc 21/06/99 liiL__~i__ _ijli_ I~ LIPI~---LIII Please note that the dimensions shown in the drawings are illustrative only, the invention is not limited to these dimensions. Electrical connectors may be made with any convenient dimensions in accordance with the principals of the present invention.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

J:\Spcci\300 399\300 349\32026.doc 21/06/99

Claims

1. An electrical connector, comprising a crimp receptacle arranged to receive a conductor and to be crimped to the conductor to provide mechanical and electrical engagement between the crimp receptacle and the conductor, the crimp receptacle including walls defining a passageway, the walls also defining an opening via which the conductor can be received into the passageway, a cross-sectional profile of the passage being quadrilateral in shape and the crimp receptacle being formed from a blank of material which is folded over so that sides of the blank meet at one side of the crimp receptacle, the arrangement being such that when a tortuous path type crimp tool is applied to opposing corners of the quadrilateral to force the corners towards each other, the crimp receptacle collapses symmetrically and evenly.

2. An electrical connector in accordance with claim I or claim 2, the electrical connector including a forwardly extending conductive portion which is joined to the crimp receptacle at a base of the crimp receptacle, the base of the crimp receptacle forming a bottom corner of the quadrilateral cross-sectional shape.

3. An electrical connector in accordance with claim 1 or claim 2, further comprising complimentary projections which interlock at the one side of the crimp receptacle where the sides of the blank meet. Dated this 6th day of September, 1999 UTILUX PTY LIMITED By their Patent Attorney GRIFFITH HACK O:\Speci300 39900 34932026.doc 6/09/99