EP1998410A1

EP1998410A1 - Electrical terminal

Info

Publication number: EP1998410A1
Application number: EP07425327A
Authority: EP
Inventors: Antonio Falchetti
Original assignee: MTA SpA
Current assignee: MTA SpA
Priority date: 2007-05-29
Filing date: 2007-05-29
Publication date: 2008-12-03

Abstract

A female electrical terminal (1) comprises a conductive body (2) having a conductive part (4) able to be coupled to a male electrical terminal (10), along a coupling axis (X-X) and in a plug-on direction (A), clamping means (20) for clamping the conductive part (4) onto the male terminal (10), and lock means (30) for engaging an abutment surface (11) of the male terminal (10), when the female terminal (1) is plugged on the male terminal (10). The lock means (30) are connected to the clamping means (20) and can be driven from a locking position to an unlocking position by counteracting an elastic return force directed towards the locking position. In the locking position, the lock means (30) engage the abutment surface (11) to prevent displacement of the female terminal (1) along the coupling axis (X-X) in the direction opposite to the plug-on direction, whereas in the unlocking position, they disengage from the abutment surface (11) to allow displacement of the female terminal (1) along the coupling axis (X-X).

Description

The present invention relates to a female electrical terminal in accordance with the preamble of claim 1. Particularly, the female terminal of the present invention may find application for ground connection to motor vehicle bodies.
A female terminal for coupling to a male terminal is disclosed, for instance, in the European patent application EP 1 729 372 .
EP 1 729 372 discloses a female electrical terminal comprising a conductive body having a conductive part able to be coupled to a male electrical terminal in a coupling direction and means for clamping such conductive part onto the male terminal. Particularly, the conductive part comprises two portions that can be moved towards each other along an axis transverse to the coupling axis, and the clamping means are operable on such portions so that their motion towards each other causes the conductive part to be clamped onto the male terminal. The clamping means comprise a holding member associated outside to the conductive part which encircles the conductive part so that such conductive part is held in contact with the male terminal. The conductive part further has a plurality of lugs which are able to abut against an axial abutment member which projects out of the male terminal transverse to the coupling axis, to prevent any axial displacement of the female electrical terminal along the coupling axis in the direction opposite to the plug-on direction, when the female terminal is plugged on the male terminal.
The above electrical terminal suffers from certain drawbacks. First, when the female terminal is to be plugged off the male terminal, the lugs of the conductive portion have to be acted upon to be disengaged from the axial abutment member of the male terminal, thereby allowing the female terminal to be displaced along the coupling axis, in the direction opposite to the plug-on direction. However, the lugs of the conductive part are not easily disengageable, as the lugs are formed directly on the conductive part which is firmly held against the male terminal by the retaining element, wherefore the lungs have to be disengaged by also counteracting the clamping action of the retaining element.
Therefore, the need arises of providing a female electrical terminal which allows quick locking and unlocking thereof on a male terminal.
Thus, the object of this invention is to provide a female electrical terminal that has such features as to fulfill the above need, while obviating the drawbacks of prior art.
This object is achieved by a female electrical terminal according to claim 1.
Thanks to the provision of lock means connected to the clamping means, the female terminal can be unlocked from the male terminal in a quick and easy manner.
Further features and advantages of the female electrical terminal of this invention, will be apparent from the following description of one preferred embodiment thereof, which is given by way of illustration and without limitation with reference to the accompanying figures, in which:

Figure 1 is a partially sectional perspective view of a female electrical terminal of the present invention,
Figure 2 is an exploded perspective view of the female terminal of Figure 1,
Figure 3 is a perspective view of the female terminal of Figure 1, when the latter is plugged on a male terminal,
Figure 4 is a partially sectional perspective view of the female terminal of Figure 1, prior to plugging thereof onto a male terminal,
Figure 5 is a partially sectional perspective view of the female terminal of Figure 1, during plugging thereof onto a male terminal,
Figure 6 is a partially sectional perspective view of the female terminal of Figure 1, when the latter is plugged on a male terminal,
Figure 7 is a perspective view of the female terminal of Figure 1, the covering and support elements being omitted,
Figure 8 is a different perspective view of the female terminal of Figure 7,
Figure 9 is a perspective view of the female terminal of Figure 7, when the latter is plugged on a male terminal.

Referring to the annexed figures, numeral 1 generally designates a female electrical terminal of the present invention.
The female electrical terminal 1 has a conductive body 2 with a first conductive part 3 able to be connected to a cable lug (not shown) and a second conductive part 4 able to be coupled, along a coupling axis, designated by X-X, and in a plug-on direction, indicated by arrow A, to a male electrical terminal 10 which mainly extends along the coupling axis X-X. The first conductive part 3 and the second conductive part 4 are interconnected by a linking portion 6.
The female electrical terminal 1 plugged on the male electrical terminal 10 forms an electrical connection 50 (Figure 3). The electrical connection 50 may be used for grounding electric and/or electronic devices. In this case, the male terminal 10 is a ground terminal attached to a structure that acts as a ground mass (not shown), whereas the ground connection of the devices to be grounded is connected, as is known per se, to the female terminal 1 by an electric cable. This provides a ground connection of the electronic devices connected to the female terminal 1 via the electric cable.
The structure that acts as a ground mass may be, for instance, the body of a motor vehicle, particularly a car.
Otherwise, the electric connection 50 may be used to connect the battery clips to the battery pole, wherein the battery clip is defined by the female electrical terminal 1 whereas the battery pole is defined by a male electrical terminal 10.
The female terminal 1 shall meet predetermined electrical conductivity requirements and is this formed of a conductive metal material, such as copper.
The male terminal 10 is formed, for instance, of a zinc-plated steel alloy. Particularly, the use of a steel alloy affords easier and safer welding of the male terminal 10 to the structure acting as a ground mass when welding on a car body.
In this example, the male terminal 10 comprises a cylindrical body 12, extending axially in the coupling direction X-X. Otherwise, the male terminal 10 may be of laminar type, or of any other shape allowing it to act as a male terminal.
According to the embodiment of the figures, the conductive part 4 comprises at least two portions 7, 8 (Figure 2) that can be moved towards each other along an axis, designated as Y-Y, which is transverse to the coupling axis X-X of the female terminal 1 and the male terminal 10. In this example, the axis Y-Y is perpendicular to the coupling axis X-X.
The terminal 1 further comprises clamping means 20 associated outside to the conductive part 4 for clamping the conductive part 4 onto the male terminal 10, and lock means 30 for engaging an abutment surface 11 of the male terminal 10 when the female terminal 1 is plugged on the male terminal 10.
Particularly, for quick and easy unlocking of the lock means 30 from the abutment surface 11 of the male terminal 10, the lock means 30 are connected to the clamping means 20 and can be driven from a locking position to an unlocking position by counteracting an elastic return force directed towards the locking position. Namely, in the locking position, the lock means 30 engage the abutment surface 11 of the male terminal 10 to prevent displacement of the female terminal 1 along the coupling axis X-X in the direction opposite to the plug-on direction, whereas in the unlocking position, the lock means 30 disengage from the abutment surface 11 of the male terminal 10 to allow displacement of the female terminal 1 along the coupling axis X-X.
In one embodiment, the lock means 30 comprise at least one lug, advantageously at least two lugs, in this example the two tabs 31, 32 being connected to the clamping means 20 and extending in inclined positions with respect to the coupling axis X-X. Particularly, the lugs 31, 32 as shown in the annexed figures extend in a direction with a component along the coupling axis X-X opposite to the plug-on direction and a component transverse to the coupling axis X-X.
This means that the two lugs 31, 32 are folded to face towards each other in the direction opposite to the plug-on direction.
Particularly, the two lugs 31, 32 are designed to engage the abutment surface 11 defined by the axial abutment member 13 which projects transversely and radially from the male terminal 10.
Alternatively, retaining teeth or extensions may be provided, projecting transversely from the clamping means 20 provided that, in the locking position, such elements engage the abutment surface 11 of the male terminal 10 to prevent displacement of the female terminal 1 along the coupling axis X-X in the direction opposite to the plug-on direction, whereas in the unlocking position, they disengage from the abutment surface 11 of the male terminal 10 to allow displacement of the female terminal 1 along the coupling axis X-X.
According to the embodiment as shown in the annexed figures, the clamping means 20 comprise a holding member 21 associated outside to the conductive part 4 to encircle the conductive part 4 so that such conductive part 4 is held in contact with the male terminal 10.
The holding member 21 may be formed, for example, of metal material or any other material having such characteristics as to be able to exert a sufficient encircling action to hold the conductive part 4 in contact with the male terminal 10. The metal material of the holding member 21 may be, for example, AISI 301 stainless steel, which has sufficient elasticity.
For the clamping means 20, i.e. the holding member 21, to be secured to the conductive part 4 of the female terminal 1, the clamping means 20 have retaining means 22 engaged with the conductive part 4. In this example, the retaining means 22 comprise a plurality of retaining tabs 22 disposed on the holding member 21 for engagement with corresponding abutment surfaces of the conductive part 4, particularly of the two portions 7, 8 to be moved towards each other. Thus, the clamping means 20 are allowed to move integrally with the conductive part 4, particularly along the coupling axis X-X, or are secured to the conductive part 4 of the female terminal 1.
According to one embodiment, the female electrical terminal 1 comprises a support element 40 and a cover element 45 (Figures 1 - 3). The support element 40 is closed at its bottom and has a receptacle 41 for receiving the conductive part 4 with the clamping means 20 secured thereto and the portion 6 of the conductive body 2 which connects the conductive part 4 to the conductive part 3. The receptacle 41 of the support element 40 is closed at its top by the cover element 45, which is secured to the support element 40 by retaining tabs 42 of the support element 40 and snap fitted in corresponding apertures 46 formed in the cover element 45. In order to allow the female terminal 1 to be plugged onto the male terminal 10, the cover element 45 has a through hole 47 for receiving the male terminal 10 along the coupling axis X-X.
It shall be noted that the cover element 45 acts as a stop element for the plug-on travel of the female terminal 1 onto the male terminal 10, to stop the travel of the female terminal 1 on the male terminal 10. Namely, the particular slightly conical shape of the male terminal 10 allows the cover element 45 to stop the displacement of the female terminal along the coupling axis X-X in the plug-on direction A when the hole 47 reaches a level of the male terminal 10 having substantially the same diameter.
In order to disengage the lugs 31, 32 of the lock means 30 of the female terminal 1 from the abutment surface 11 of the male terminal 10, two through apertures 43, 44 are formed in the support element 40, for access to the lugs 31, 32 and disengagement of the lugs 31, 32, using a specially shaped tool, from the abutment surface 11 when the female terminal 1 is plugged on the male terminal.
It should be further noted that the receptacle 40 has the function to limit the travel of the two lugs 31, 32 along the axis Y-Y transverse to the coupling axis X-X, as they are moved from the locking position to the unlocking position.
Prior to plugging the female terminal 1 onto the male terminal 10 (Figure 4), the lugs 31, 32 are substantially in a locking position. Then, as the female terminal 1 is plugged onto the male terminal 10, the lugs 31, 32 abut against the axial abutment member 13 of the male terminal 10, which projects transverse to the coupling axis X-X and is defined at the top end 10a of the male terminal 10. The abutment member 13 pushes the lugs 31, 32 outwards, along the transverse axis Y-Y, thereby counteracting the elastic return force directed towards the locking position of the lugs 31, 32 (Figure 5).
As the female terminal 1 is further plugged onto the male terminal 10 along the coupling axis X-X, the lugs 31, 32 move past the abutment member 13 of the male terminal 10 until they reach an annular groove 14 having a smaller diameter than the abutment member 13 and, under the elastic return force which pushes them towards the locking position, they reach the locking position against the abutment surface 11.
In this position, any attempt to move the female terminal along the coupling axis X-X in the direction opposite to the plug-on direction is prevented by the engagement of the lugs 31, 32 with the abutment surface 11 of the male terminal 1. In this example, the abutment surface 11 is defined by the bottom surface of the axial abutment member 13 of the male terminal 1.
Whenever a user wants to unplug the female terminal 1 from the male terminal 10, he/she simply has to introduce a specially shaped tool in the two through apertures 43, 44 and disengage the two lugs 31, 32 from the abutment surface 11 of the male terminal 1 to allow displacement of the female terminal 1 along the coupling axis X-X in a direction opposite to the plug-on direction, while maintaining the two lugs 31, 32 disengaged until the two lugs 31, 32 move past the axial abutment member 13 of the male terminal 10.
It will be appreciated from the above that the female electrical terminal of the present invention obviates prior art drawbacks. Namely, the provision of lock means connected to the clamping means allows the female terminal can be unlocked from the male terminal in a quick and easy manner.
Those skilled in the art will obviously appreciate that a number of changes and variants may be made to the female electrical terminal of the invention as described hereinbefore to meet specific needs, without departure from the scope of the invention, as defined in the following claims.

Claims

A female electrical terminal (1) comprising:
- a conductive body (2) having a conductive part (4) able to be coupled to a male electrical terminal (10), along a coupling axis (X-X) and in a plug-on direction (A),

- clamping means (20) associated outside to the conductive part (4) for clamping said conductive part (4) onto said male terminal (10),

- lock means (30) for engaging an abutment surface (11) of said male terminal (10), when the female terminal (1) is plugged on the male terminal (10),
characterized in that
- said lock means (30) are connected to said clamping means (20) and can be driven from a locking position to an unlocking position by counteracting an elastic return force directed towards said locking position,
in said locking position, said lock means (30) engage said abutment surface (11) of the male terminal (10) to prevent displacement of the female terminal (1) along said coupling axis (X-X) in the direction opposite to the plug-on direction, and
in said unlocking position, said lock means (30) disengage from said abutment surface (11) of the male terminal (10) to allow displacement of the female terminal (1) along said coupling axis (X-X).
A female electrical terminal (1) as claimed in claim 1, wherein said lock means (30) comprise at least one lug connected to said clamping means (20) and extending at an angle to said coupling axis (X-X).
A female electrical terminal (1) as claimed in claim 1, wherein said lock means (30) comprise at least two lugs (31, 32) connected to said clamping means (20) and extending at an angle to said coupling axis (X-X).
A female electrical terminal (1) as claimed in claim 3, wherein said at least two lugs (31, 32) extend in a direction with a component along said coupling axis (X-X) opposite to the plug-on direction (A) and a component transverse to said coupling axis (X-X).
A female electrical terminal (1) as claimed in any one of claims 2 to 4, wherein said at least two lugs (31, 32) comprise two lugs folded to face towards each other in the direction opposite to the plug-on direction (A).
A female electrical terminal (1) as claimed in any one of claims 1 to 5, wherein said clamping means (20) comprise a holding member (21) associated outside to said conductive part (4) to encircle said conductive part (4) so that said conductive part (4) is held in contact with said male terminal (10).
A female electrical terminal (1) as claimed in claim 6, wherein said clamping means (20) comprise retaining means (22) engaging said conductive part (4) to secure said clamping means (20) to said conductive part (4).
A female electrical terminal (1) as claimed in claim 6 or 7, wherein said lock means (30) are disposed on said holding member (21).
An electrical connection (50) comprising:
- a female electrical terminal (1) as claimed in any one of claims 1 to 8,

- a male electrical terminal (10) having an abutment surface (11),
the lock means (30) of said female electrical terminal (1) engaging said abutment surface (11), in said locking position, to prevent displacement of the female terminal (1) along said coupling axis (X-X) in the direction opposite to the plug-on direction (A).
An electrical connection (50) as claimed in claim 9, wherein said male electrical terminal (10) mainly extends along said coupling axis (X-X), said abutment surface (11) extending radially with respect to the coupling axis (X-X).