GB2184900A

GB2184900A - A rapid-coupling terminal for a terminal pole of an electrical apparatus

Info

Publication number: GB2184900A
Application number: GB08630449A
Authority: GB
Inventors: Luciano Obert
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-12-23
Filing date: 1986-12-19
Publication date: 1987-07-01
Also published as: ES2004506A6; IT8568103A0; FR2592234B3; IT1184045B; FR2592234A1; DE3643087A1; GB8630449D0

Abstract

The terminal comprises an electrical contact element (4) provided with a pair of elastically deformable walls (6), the inner surface of which can be coupled with the lateral surface (2) of a terminal pole and which are rigidly connected together at a root zone (8). The terminal further includes manually operable deformation means (35) able to deform each of the said walls elastically in such a way that this elastic deformation generates between the lateral surface of the pole and the inner surface of each wall a pressure of a predetermined value to effect electrical connection between the contact element and the pole, the means having a cam portion which elastically deforms the walls and a portion (41) which covers and projects the contact. <IMAGE>

Description

SPECIFICATION A rapid-coupling terminal for a terminal pole of an electical apparatus The present invention relates to a rapid-coupling terminal for a terminal pole of an electrical apparatus, in particular for terminal poles of a motor vehicle electric battery.

As is known, connection between an external cable and a terminal pole of an electrical apparatus is normally obtained by means of a terminal provided with threaded connection members; the operations necessary for connecting and disconnecting a terminal of this type to the associated pole are rather lengthy and always require the use of auxiliary tools.

Rapid-coupling terminals are also known, with which the said operations can be effected more rapidly and without the use of tools; such terminals, however, have the disadvantage of being constructionally very complex, because they are constituted by a large number of parts, and of not obtaining a satisfactory electrical contact because of the limited contact area between the terminal and the pole and the fact that the pressures which are transmitted between the first and the second are not very high and are non-uniform. Such terminals are, therefore, expensive and of low reliability.

The object of the present invention is that of providing a rapid-coupling terminal for a ter minal pole of an electrical apparatus, in particular for the terminal pole of a battery for a motor vehicle, by means of which the above noted disadvantages are eliminated, and which is therefore, of very simple construction and of low cost, and with which it is possible to obtain a good, substantially stable long term electrical contact, and which does not require any maintenance.

This object is obtained by means of a rapidcoupling terminal for a terminal pole of an electrical apparatus, the said pole being delimited by a lateral surface, characterised by the fact that it includes an electrical contact element provided with a pair of elastically deformable walls the inner surfaces of which can be coupled to the said lateral surface of the pole and which are connected together rigidly at a root zone, and manually operable deformation means for the said electrical contact element operable to reform each of the said elastically deformable walls elastically, in such a way that following the said elastic deformation a pressure having a predetermined value is generated between the said lateral surface of the said pole and the said inner surface of each wall for effecting electrical connection between the said electrical contact element and the said pole.

For a better understanding of the present invention a more detailed description of it will now be given, by way of example, with reference to the attached drawings, in which: Figure 1 is a perspective representation of various parts of which the connection terminal of the invention is composed: Figure 2 is a perspective representation of the terminal of the invention in a configuration in which this terminal is fitted to the pole of the electrical apparatus to which it is to be connected, but is not yet locked thereto; Figure 3 is a perspective representation of the terminal of the preceding Figure, in a second configuration in which the terminal itself has been locked onto the said pole; Figure 4 is a partially sectioned plan view from above of the terminal of Fig. 3; Figures 5, 6 and 7 are three sections taken, respectively, on the lines V-V, VI-VI and VI I-VII;; Figure 8 is a perspective representation of a further embodiment of the terminal of the invention; Figure 9 is a section of the terminal of Fig.

8 taken on the line IX-IX; Figures 10 and 11 perspectively represent two different embodiments of a cam with which the terminal of the invention is provided; Figure 12 represents a plan view of a blank utilised for the construction of the terminal of the invention; and Figure 13 is a plan view of another blank from which the terminal of the invention can be obtained, in a working stage subsequent to that with which the terminal of Fig. 12 has been obtained.

The terminal of the invention is able to obtain a rapid coupling with a terminal pole of an electrical apparatus, conveniently with the pole 1 of a battery of a motor vehicle; such pole can have and form and conveniently is delimited by a conical lateral surface 2.

The terminal of the invention, generally indicated with the reference numeral 3, substantially comprises an electrical contact element 4, which is clearly seen in Fig. 1, in which it has been shown together with a cam 5 which forms part of the terminal itself; the contact element 4 is provided substantially with a pair of elastically deformable walls 6 the inner surface 7 of which can be coupled with the conical lateral surface 2 of the pole 1. Therefore, the inner surface 7 is substantially conical and the elastically deformable walls 6 are also conical, as can be clearly seen from Fig. 1.

These walls are rigidly connected together at a root zone 8 from which extends a connection member 9 which can be connected to an electrical cable 10 (Figs. 2 and 3); this member, as is clearly seen from Fig. 1 is formed integrally with the elastically deformable walls 6 and is provided with a first and a second pair of plastically deformable tabs 13 and 14 respectively, operable to lock the connection member to the conductor 15 and the sheath 16 of the cable 10 respectively. Conveniently the electrical connection member 9 projects substantially in a radial direction with respect to the pair of elastically deformable walls 6 and has a channel form; the first part 17 of this member, which extends from the root zone 8 of the walls 6 has substantially two pairs of side walls 18 and 19 which define a channel 20 of rectangular section.Conveniently a tongue 21 of the wall 19 which is lowermost in Fig. 1, is turned over the adjacent side wall 18 in such a way as to form, in correspondence with the said root zone 8 of the walls 6, a very rigid and robust structure.

The terminal includes manually actuable means for deformation of the electrical contact element 4, operable elastically to deform each of the elastically deformable walls 6; the said means substantially comprise a pair of tongues 24 each of which is formed on the free end of a corresponding wall in a position diametrically opposite that in which the electrical connection member 9 is located; the two tongues are substantially parallel and suitably spaced, in such a way as to leave between them a space 25 of predetermined width. The said means further include the first mentioned cam 5 which is substantially turnable about an axis 26 orthogonal to the axis of the pole 1, and is provided with a pair of projections 27 each of which projects towards the tongues 24 as is clearly seen from Fig. 1 and from Fig. 10 (which shows the cam 5 visible in Fig.

1); this cam has a substantially U-shape form with a pair of tongues 28 between which are disposed the tongues 24 of the walls 6 and from each of which projects a corresponding projection 27; each of these is obtained conveniently by folding the end part of the corresponding tongue 28 and this projection has an active edge 29 of substantially curvilinear form. The cam 5 is pivoted on a pin 30 which traverses a hole in the tongues 24 in such a way as to be turnable with respect to these about the axis 26.

Conveniently, the cam 5 has an appendage 31 which projects upwardly from the tongues 28 and which can be connected in a manner which will be explained, to an operating lever of the terminal. In a first embodiment of the cam 5, shown in Fig. 10, the appendage 31 has a substantially U-shape section and projects upwardly from the rear part of the tongues 28; in the embodiment of Fig. 11 it has a pair of appendages 3 1 each of which is obtained simply by extending the front part of each tongue 28 upwardly. Moreover, for further reinforcement of the cam 5 there can conveniently be provided other suitably folded tongues such as the tongue 34 (Fig. 10) which connects the two tongues 28.

The electrical contact element and the cam 5 are made of sheet metal by means of cutting and plastic deformation operations such as folding, drawing and the like.

The terminal also includes an operating lever 35 (Figs. 2 and 3) rigidly connected to the pivoting cam 5. This latter substantially comprises a housing 36 for the cam 5, formed between a pair of tongues 37 provided with holes which can be traversed by the pin 30 which pivots the cam with respect to the electrical contact element 4; this lever includes a cover part 38 for the pole 1 and another cover having resiliently deformable tongues 39 provided with gripping teeth 40 (Fig. 5) provided for snap-engaging under the first part 17 of the connection member 9 for the purpose of locking the lever itself with respect to the electrical contact element 4.

The lever 35 also includes a suitably shaped end part 41 which can form a cover for the connection member 9 of the terminal, as is clearly seen in Fig. 3; this lever can be provided with suitable slots 42 formed in correspondence with the elastically deformable walls 6 for the purpose of allowing cooling of this zone of the terminal.

The connection of the cam 5 to the lever 35 is achieved conveniently by inserting the appendage 31 of the former within a corresponding cavity 43 (Fig. 8) formed in the lever itself. For the axial fixing of the pin 30 with respect to the lever 35 there are formed, on the inner surface of the hole which is formed in each tongue 37 (visible in section in Fig. 7), annular projections 44 which can a exert pressure of a predetermined force on the outer surface of the pin 30 to lock it within the associated holes.

In Fig. 8 there is shown a terminal the lever 34 of which is shaped in a slightly different way from that of Fig. 3, for the purpose of obtaining a more complete protection of the electrical contact element 4.

The electrical contact element 4 can be made from a continuous strip of metal sheet by means of cutting, folding and drawing operations: as is visible in Fig. 12, a substantially flat blank 45 can first be obtained, having an outline such as to give rise, through further plastic deformation operations on the blank itself, to the completely finished electrical contact element 4; each blank 45 is obtained from a continuous strip by means of cutting and plastic deformation operations of the metal sheet, and at the end of the said operations it is connected to a continuous strip 46 through a bridge 47. By separating the blank 45 from this strip and subjecting it to further drawing and folding operations, the completely finished electrical contact element 4 can be obtained as has been shown in Fig.

13.

All the operations indicated for forming the electrical contact element 4 and those necessary for forming the cam 5 can be effected in an entirely automatic way in a known manner.

Similarly, the lever 5 of the terminal, which is conveniently constructed in synthetic material, preferably in thermopiastic material, can also be formed, and completely finished, in an entirely automatic manner. Finally, the operations necessary for assembly of the terminal, consisting substantially in connecting the cam 5 to the lever 35 and in pivoting the unit constituted by the cam and the lever onto the electrical contact element 4 by means of the pin 30, can also be effected in an entirely automatic manner utilising machines and devices of known type.

The operation of the terminal described is as follows.

After the cable 10 has been fixed to the electrical connection member 9 of the terminal by folding over the tabs 13 and 14 respectively onto the conductor 15 and the sheath 16, the terminal can be connected to the pole 1 by coupling the internal surface 7 of the walls 16 with the outer surface 2 of the pole 1, as has been shown in Fig. 2; during this operation the lever 35 is located in the raised configuration as shown in this Figure, in which the projections 27 of the cam 5 are completely disengaged from the tongues 24 of the electrical contact element 4.In this configuration the tongues 24 are completely spaced from one another and are substantially in contact with the inner surface of the arms 28 of the cam 5: the conical surface which is defined overall by the inner surfaces 7 of the wall 6 has dimensions greater than those of the lateral surface 2 of the pole 1 and therefore the terminal can be coupled to this pole with extreme ease and without force. To fix the terminal onto the pole it is sufficient to cause the lever 35 to turn in an anti-clockwise sense in Fig. 2, lowering it over the electrical contact element as has been shown in Fig. 3.

During this rotation, which is substantially through 90 , the active edges 29 of the projections 27 of the cam 5 come into cooperation with the outer surfaces of the tongues 24 of the walls 6, applying to these sufficiently high pressure to elastically deform the walls themselves; consequently between the inner surface 7 of these walls and the outer surface 2 of the pole 1 there are exerted high pressures for the purpose of effecting a good electrical contact between the electrical contact element 4 and the pole. In this second configuration the two tongues 24 of the walls 6 are located at a short distance from one another as can be clearly seen from Fig. 4, but still leave a space of small dimensions between them.In the same configuration the tongues 39 (Fig. 5) cooperating with the walls 18 of the first part 17 of the connection member 9 are resiliently deformed and the associated teeth 40 snap-engage under the wall 19 locking the lever 35 over the electrical contact element and substantially preventing accidental opening. In the same configuration the cover part 38, the tongues and the lateral walls of the lever 35 form a complete cover over the electrical contact element 4 and the cam 5 for the purpose of obtaining a perfect isolation from the environment and an effective protection against external agents.

The operation of disengaging the terminal is obviously effected by making the lever 35 turn in an opposite sense, that is upwardly.

From the description of the structure and operation of the terminal of the invention the favourable characteristics with which it is provided and the important advantages obtainable with it will be evident.

First of all, it is very simple in construction because of the few number of parts with which it is made and the form of these. Moreover, these parts can be made in an entirely automatic manner and the operations necessary for assembly of the parts themselves for the purpose of obtaining the completely finished terminal can also be performed in an entirely automatic manner by means of known machines; consequently, the terminal can be obtained at low cost. Because of the small number of parts of which it is constituted, and the materials with which these are made, it can also be of very low weight.

With this terminal it is possible to obtain a perfect electrical contact both because of the extended contact surface between the electrical contact element and the pole 5, and because of the high pressure which can be exchanged between these parts; in fact, because of the elastic deformation to which the elastically deformable walls 6 are subjected upon actuation of the cam 5, the entire inner surface 7 of these are tightly in contact with the corresponding parts of the lateral surface 2 of the pole 1; it must therefore be borne in mind that the arc of contact in the coupling between the pole and the electrical contact element 4 is substantially 360" and therefore much better than that attainable with terminals of prior art type.Moreover, the contact pressures, which can assume any desired value dependent on the rigidity of the elastically deformable walls 6, remain substantially unchanged with the passage of time, with the advantage of having a high reliability of the device and of not requiring maintenance operations thereof. Because of the form of the connection member 9, having substantially channel shape closed at its upper part, the possible formation of condensation does not bring about any disadvantage to the terminal: in fact this tends to fall downwardly from the lower part of the folded tabs 13 and 14 with which the connection member is provided.

Finally, with the terminal of the invention there is obtained a perfect isolation from the exterior and an effective protection from the surrounding environment because of the complete screening obtained by the lever 35.

It is evident that the form and arrangement of the various parts of the terminal which has been described can be modified and varied without by this departing from the ambit of the invention.

In particular, the form of the elastically deformable walls 6 of the electrical contact element 4 can be modified in an obvious manner and be different from that described and illustrated for the purpose of being able to connect with poles 1 of different form, having, for example, a square, rectangular of polygonal section; moreover, on parts of these elastically deformable walls 6 there can be formed projections for the purposes of increasing the contact pressure with the pole in correspondence with desired zones of the coupled surfaces of the pole and the walls.

Moreover, each tongue 24 (Fig. 4) of a lateral wall 6 can have an end tooth projecting towards the other tongue; in this way when the terminal is in its closure position as in Fig.

3, these teeth are in contact with one another in such a way as to increase the elastic reaction which these tongues transmit to the projections 27 of the cam 5. Finally, the cam could be shaped in such a way as to include the lever 35, which therefore in this case would form an integral part of the cam itself and would be made of the same material.

Claims

1. A rapid-coupling terminal for a terminal pole of an electrical apparatus, the said pole being delimited by a lateral surface characterised by the fact that it comprises an electrical contact element connectable to an electrical conductor and provided with a pair of elastically deformable walls the inner surface of which can be coupled to the said lateral surface of the pole and which are rigidly connected together at a root zone, and manually operable deformation means of the said electrical contact element operable to deform elastically each of the said elastically deformable walls in such a way that following the said elastic deformation a pressure having a predetermined value is generated between the said lateral surface of the said pole and the said inner surface of each wall for effecting electrical connection between the said electrical contact element and the said pole.

2. A terminal according to Claim 1, characterised by the fact that the said deformation means include a pair of first, substantially parallel tongues, each of which is formed on the free end of one of the said walls, and a cam pivoted substantially about an axis orthogonal to the axis of the said pole, which is provided with a pair of projections each of which projects towards the said tongues, the said cam being movable from a first configuration in which the said tongues are not located between the said projections and a second configuration in which the said tongues are housed between the said projections in such a way that these exert predetermined pressure on them elastically to deform the said elastically deformable walls.

3. A terminal according to Claim 1 or Claim 2, characterised by the fact that the said cam has a substantially U-shape form with a pair of second tongues between which the said first tongues are disposed, the said cam being pivoted on a pin which traverses the said first tongues and each of the said projections projecting from the free end of a corresponding said second tongue.

4. A terminal according to Claim 3, characterised by the fact that each of the said projections is formed by folding the end part of the corresponding second tongue, the said end parts having an active edge of curvilinear form.

5. A terminal according to any preceding Claim, characterised by the fact that the said inner surface of each of the said elastically deformable walls of the said contact element is conical.

6. A terminal according to any of Claims from 1 to 4, characterised by the fact that the said inner surface of each of the said elastically deformable walls comprises a plurality of flat wall portions.

7. A terminal according to any of the preceding Claims, characterised by the fact that the said electrical contact element includes an electrical connection member operable to connect the electrical contact element with the said electrical conductor, the said connection member being formed integrally with the said elastically deformable walls and being provided with plastically deformable tabs for locking the said conductor and the sheath of the conductor to the said connection member.

8. A terminal according to Claim 7, characterised by the fact that the said electrical connection member projects from the said root zone of the said elastically deformable walls and has a channel form.

9. A terminal according to Claim 8, characterised by the fact that the first part of the said electrical connection member which joins the said root zone of the elastically deformable walls has two pairs of lateral walls and defines a channel, the said plastically deformable tabs of the connection member being formed on the end part of the member itself.

10. A terminal according to any preceding Claim, characterised by the fact that the said electrical contact element is formed from a strip of sheet metal by cutting, folding and drawing operations, at the end of the said operations the said electrical contact element being connected to a continuous strip of the said sheet metal from which it is separated during the terminal assembly operations.

11. A terminal according to any of the preceding Claims, characterised by the fact that the said deformation means of the said contact element include an actuating lever rigidly connected to the said pivoted cam.

12. A terminal according to Claim 11, characterised by the fact that the said lever includes a housing for the said pivoted cam, a cover part for the said pole and a pair of deformable tongues provided with hooking teeth positioned to snap-engage under the said first part of the said electrical connection member to lock the said lever with respect to the electrical contact element.

13. A terminal according to any of Claims from 2 to 12, characterised by the fact that the said cam has an appendage which can be inserted into a corresponding cavity of the said lever.

14. A terminal according to any of Claims from 11 to 13, characterised by the fact that the said lever includes cover parts for the said electrical connection member.

15. A rapid-couping terminal for a terminal pole of an electrical apparatus, substantially as described and illustrated in the attached drawings.