GB2042825A - Battery terminal harness with polarity protector - Google Patents

Abstract

A battery terminal harness 18 to connect to a battery 10 has a male first terminal 22 to couple to a female first battery terminal 12 of one polarity, a female second terminal 24 to couple to a male second battery terminal 14 of the opposite polarity, terminals 22, 24 being mounted on and extending a fixed distance D from an insulating support 20, and an insulating washer-like resilient plastics cover member 36 having a thickness T exceeding the distance D and having tabs 40 for securement to terminal 24. The cover member 36 snaps over and is secured to the terminal 24, whereby the cover member 36 prevents any contact between the female terminals 12, 24 at all times to avoid inadvertent reversal of polarity, an opening 38 (Fig. 2) in cover 36 being too small to allow passage therethrough of terminal 12 but allowing terminal 14 to pass through into engagement with terminal 24. <IMAGE>

Description

SPECIFICATION Polarity protector The invention is directed to a battery terminal harness capable of preventing the application of reverse polarity voltage to a circuit connected to the harness.

For proper operation, many battery-operated electrical circuits including virtually all electronic circuits, must be connected to the battery with a particular polarity. The "positive" polarity input terminal to the circuit must be connected to the positive or plus terminal of the battery and the "negative" polarity input terminal to the circuit must be connected to the negative or minus terminal of the battery. To assure proper polarity connections, it is common to use batteries having dissimilar terminals and battery terminal harnesses having mating dissimilar connectors~ generally a male stud-like connection and a female flexible peripherally spaced finger connection.By connecting the harness to the electrical circuit in the desired manner, the user can be assured that the battery is connected with the correct polarities since the battery terminals and the terminal connectors will mate with only the desired polarity. Nevertheless, reverse voltage can be applied to the circuit if the harness connectors are inadvertently pressed against the battery terminals in reverse orientation. While the battery terminals will not mate with the harness connectors in the reverse position, the short term reverse voltage applied to the circuits by such connection may damage or lessen the reliability of the circuit. Accordingly, it is common to protect the circuit against the application of short-term reverse voltage by means of an appropriate diode or other one-way protective device.This approach is not always desirable, however, since such protective elements introduce operating deficiences and result in extra cost.

According to the invention, there is provided a battery terminal harness for connection to a battery, the harness having a first male terminal for coupling to a first female battery terminal of one polarity, a second harness female terminal for coupling to a second male battery terminal of the opposite polarity, and an insulating support member, each of the male and female harness terminals being mounted on and extending a fixed distance from the support member and being arranged to mate electrically with its opposite battery terminal, there being provided an insulating cover member covering one of the harness terminals and having an opening therein, the configuration of the opening being such that the corresponding one of the terminals of the battery is sufficiently small to pass therethrough to mate with the one harness terminal and the other terminal of the battery is too large to pass therethrough to contact the one harness terminal.

A preferred embodiment of the invention comprises a standard battery terminal harness provided for connection to a battery, the harness having a first ma;e terminal coupled to a first female battery terminal of one polarity and a second female terminal coupled to a second male battery terminal of the opposite polarity. the harness further comprises an insulating support member having an opening between the harness terminals and having the male and female harness terminals each mounted on the support member and extending a fixed distance therefrom and adapted to mate electrically each with its opposite battery terminal. Wire means is locked through the support opening connecting each of the harness terminals with an electric circuit.An insulating washer-like cover member of integrally molded resilient plastics is removably secured and supported solely by one harness terminal, preferably the female terminal, with the washer cover member having a thickness exceeding the fixed distance of the harness terminals. The washer cover has radially inwardly extending tabs on its inner and outer ends and has a diameter less than the diameter across the female terminal such that the washer member may be snapped over the female terminal with the inner tabs retaining the cover on the female terminals and the outer tabs preventing contact between a like terminal such as a battery female terminal to preclude reverse polarity contact of the harness and battery terminals at all times.

The invention will be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shown a standard 9-volt battery with dissimilar terminals and a terminal harness constituting a preferred embodiment of the present invention; Figure 2 is an exploded perspective view to the terminal harness of Figure 1; Figure 3 is a plan view of the terminal harness of Figure 1; Figure 4 is an exploded elevation view showing the parts of Figure 1 and taken partly on line 4-4 of Figure 3; and Figure 5 is a sectional view of a cover member taken on line 5-5 of Figure 3.

Referring first to Figure 1, a typical 9-volt battery 10 of the type widely used to power electronic circuits is shown, the battery 10 having dissimilar negative and positive terminals 12 and 14 respectively. The first negative female terminal 1 2 is of annular resilient finger configuration for peripherally engaging a cylindrical male stud member having substantially the same configuration as the positive male battery terminal 14 also of cylindrical stud configuration. More particularly, the negative terminal 12 is of general cylindrical configuration with axially extending radially resilient fingers 16 for radially coupling the outer cylindrical surface of a male stud harness terminal of opposite polarity.The axes of the negative and positive terminals 12 and 14 are typically spaced apart by approximately one half inch (2.54 cm) in conventional well known 9-volt batteries of the flat type as shown in Figure 1.

The battery terminal harness 18 as shown in Figures 1-4 includes an insulating support member 20 of fiber-board or other insulating material upon one side of which a first male harness terminal connector 22 and a second female harness terminal connector 24 are mounted with each terminal extending a fixed distance D from the support member as shown in Figure 4. The first male terminal connector 22 has a mating configuration for the negative battery terminal 12 such that the negative battery terminal 12 can be snapped over the connector 22, the fingers 16 of the terminal 12 resiliently engaging the outer cylindrical surface such as 30 of the connector 22.Similarly, the second female terminal connector 24 is a mating configuration for the second positive battery terminal 14 such that the positive battery terminal 14 can be snapped into the connector 24, the annular spaced deformable fingers 26 of the connector 24 resiliently engaging the outer cylindrical surface 28 of the male terminal 14. The axes of the harness terminals or connectors 22 and 24 are spaced apart by substantially the same amount as the battery terminals 12 and 14 such that the terminals 12 and 14 may be simultaneously engaged with the connectors 22 and 24 respectively as best shown by Figure 4. The resilient connections between the terminals assures that the battery terminal harness 18 is firmly held on the battery 10. Such structure as presently described is generally well known and common to all 9-volt battery electrical applications.

As best shown by Figures 3 and 4, the terminal connector 24 is connected to an electrical lead wire 32 directed to the opposite side of the insulating support member 20, and the terminal connector 22 is connected to an electrical lead wire 34 which also comes out of the opposite side of the insulating support member 20. Since the connector 24 can only mate with the positive battery terminal 14, the lead wire 32 is the positive lead to any circuit connected to the battery terminal harness. Similarly, since the male connector 22 can only mate with the negative battery terminal 12 the lead 34 is the negative lead to any circuit connected to the battery terminal harness 18.

Strain relief and locking is provided by reverse feeding the lead wires 32 and 34 through a circular opening 35 in the insulating support member disposed between the harness terminals or connectors22 and 24.

An insulating washer-like cylindrical cover member 36 is provided for assuring that reverse voltage cannot be applied at any time to the leads 32 and 34 and thus any circuit connected thereto.

Reverse polarity voltage could be applied if the terminal 14 and the connector 22 were touched and the terminal 12 and the connector 24 were touched at the same time. Even through the harness 18 could not be snapped onto the battery 10 under these conditions, the short-term reverse voltage could cause failure or reduce the life of many electronic circuits normally powered in the illustrated manner.

As shown, insulating cylindrical cover member 36 forms a cup over terminal connector 24. Cover member 36 has a circular opening 38 therein with the opening being large enough to permit the battery terminal 14 to pass through to couple with the second female harness terminal 24. Part of the inner diameter of opening 38 of the cover member is less than the diameter across the spaced deformable fingers 26 of the female terminal 24 so the cover member 36 may be snapped snugly on the terminal slightly deflecting the fingers 26 as shown in Figure 4. In order to prevent any reverse polarity, the washer cover 36 is formed to have a thickness T that exceeds the fixed distance D of the harness terminals by a small amount as shown in Figure 4.Additionally, for securing the cover 36 in position it is formed with peripherally spaced radially inwardly extending tabs 40 on the inner end of the cover member and outer tabs 42 on the outer end of the cover. The diameter across the inner tabs is less than the diameter across the deformable fingers 26 of female terminal 24, the arrangement being such that the cover member may be snapped only onto terminal 24 over the annular spaced fingers 26 to lock under them as shown in figure 4 and hold the cover 36 snugly in place. For preventing any contact by a like female terminal, the cover 36 is also provided with peripherally spaced radially extending inward tabs 42 on the outer end of the cover. The ends of the fingers 26 are clearly shown in Figure 4.This arrangement precludes any possible connection between like female terminals while permitting unobstructed connection by the male terminal 14 of the battery. Also the parts are sized such that the cover member 36 clearly will not fit one the harness terminal 22 since it is too large for the male terminal.

The arrangement of the simple washer-like plastic resilient cover member 36 is such that it may easily be snapped on the female hardness terminal 24 during assembly of the particular electronic component and is removably secured only to the terminal requiring no additional structure to secure it to the support member 20. The part is easily molded in one piece and the dimensions may be varied so long as the thickness T is greater than the fixed extension distance D of the terminals. Finally, as part of the molding there is a means such as tabs 42 to prevent any contact with the matching terminal at all times.

Claims (9)

1. A battery terminal harness for connection to a battery, the harness having a first male terminal for coupling to a first female battery terminal of one polarity, a second harness female terminal for coupling to a second male battery terminal of the opposite polarity, and an insulating support member, each of the male and female harness terminals being mounted on and extending a fixed distance from the support member and being arranged to mate electrically with it opposite battery terminal, there being provided an insulating cover member covering one of the harness terminals and having an opening therein, the configuration of the opening being such that the corresponding one of the terminals of the battery is sufficiently small to pass therethrough to mate with the one harness terminal and the other terminal of the battery is too large to pass therethrough to contact the one harness terminal.

2. A harness as claimed in claim 1, further comprising fastening means for securing the cover member in position over the one harness terminal.

3. A harness as claimed in claim 1 or 2, wherein the cover member has a height which is greater than the said fixed distance.

4. A harness as claimed in any one of the preceding claims, wherein the second harness female terminal comprises annularly spaced deformable finger portions for peripherally engaging the male battery terminal in the form of a cylindrical male stud terminal and the insulating cover member is removably secured to the second harness female terminal.

5. A harness as claimed in claim 4, wherein the cover member is cylindrical and integrally formed of resilient plastics.

6. A harness as claimed in claim 5, wherein the diameter of one end of the cylindrical plastics cover member is less than the diameter across the deformable fingers of the second harness female terminal for snugly snapping the resilient cover member over the second harness female terminal.

7. A harness as claimed in claim 6, wherein the cylindrical plastics cover member is formed with peripherally spaced radially inwardly extending tabs at the inner and outer ends of the cover member, the inner tabs forming the reduced diameter end for snapping over the annular spaced deformable fingers which hold the cover member in place, and the outer tabs covering the ends of the fingers for preventing contact between the second harness female terminals and the battery female terminal.

8. A battery terminal harness for connection to a battery, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

9. An electrical or electronic apparatus including a harness as claimed in any one of the preceding claims.