Self-insulating electrical terminal block

Abstract

Self-insulating electrical terminal block (1) for electrical conductors, which has a terminal housing (2) in the interior of which two recesses (10, 11) are provided, and which has in each recess (10, 11): - a cable lug (14, 15) made of an electrically conductive material; - a sliding part (12, 13) made of an electrically insulating material, wherein the sliding part (12, 13) is provided with at least one axial channel (30, 31) capable of receiving a conductor, wherein the sliding part (12, 13) is displaceable in the recess (10, 11) along an axis that extends transversely to a direction of introduction of the conductor into the sliding part (12, 13) between a first position which enables the introduction of the conductor into the or each axial channel (30, 31) and a second position in which the conductor is brought up to the cable lug (14, 15), and the terminal (1) has locking means (B, L, L') which are arranged to lock the respective sliding part (12, 13) in the first and second positions, wherein the locking means (B, L, L') for each sliding part (12, 13) have a bead (B) provided on the sliding part (12, 13) and two recesses (L, L') provided in the terminal housing (2) and into which the bead (B) engages in one and the other from the first and second positions, wherein each sliding part (12, 13) has a recess (E) provided to facilitate deformation of the sliding part (12, 13) in the vicinity of the bead (B) to assist engagement and disengagement of the bead (B) into and out of the recesses (L, L'), wherein each sliding part (12, 13) is mounted such that it can be linearly displaced under the action of a pivoting movement of a tool (O), wherein each recess (10, 11) for the insertion of a conductor is associated with an opening (8, 9) which is provided at the upper end (6) of the terminal housing (2) and leads to the associated recess (10, 11), wherein the thickness at the upper end (6) of the terminal housing (2) is selected such that effective retention of the conductor is enabled without impairing its insulation.

Description

[0001] The invention relates to self-insulating electrical terminal blocks.

[0002] In fact, according to the state of the art, an electrical connection can be achieved using either a screw terminal, a spring terminal, or a terminal with self-insulating contact edges.

[0003] When a screw terminal block is used, a conductor is clamped between a fixed part and a movable part by means of a screw.

[0004] In spring-loaded terminals, the electrical connection is made by using a movable piece of metal which is subjected to pressure against a stationary piece of metal under the action of a spring.

[0005] This type of terminal block is unsuitable for environments subject to vibration. In any case, making the connection is relatively time-consuming and tiring. In fact, it is necessary to strip the conductors before making the connection.

[0006] Terminals with self-insulating contact edges are advantageous in that it is not necessary, or rather, not necessary at all, to strip the conductors before connecting them.

[0007] Different types of terminal blocks for self-insulating connections are known from the state of the art.

[0008] In this regard, reference can be made to documents US 6 692 292 and EP-A-1 191634.

[0009] The self-insulating terminals described in these publications each have a terminal housing in the interior of which at least one recess is provided, and each recess has a stationary cable lug made of an electrically conductive material, as well as a sliding part made of an electrically insulating material capable of receiving a connecting conductor, wherein the sliding part is displaceable in the recess between a first lateral position, which enables the insertion of a conductor into the sliding part, and a second lateral position, in which the conductor is brought up to the cable lug.

[0010] This type of clamp has one important disadvantage.

[0011] In fact, it can happen that the sliding part is in an arbitrary intermediate position between the first and second positions, which in this case makes connecting more complicated because inserting the conductor into the sliding part becomes more difficult.

[0012] If the terminal is intended to be used in an environment subject to strong vibrations or shocks, for example if it is intended to form part of an aircraft's electrical system, it is absolutely essential that the sliding part retains its connection position, because otherwise it would be capable of causing unintentional interruptions.

[0013] FR 2 516 711 A1 describes a self-insulating electrical terminal for electrical conductors, comprising a terminal housing made of an insulating material with an internal recess. This recess accommodates a connecting piece made of an electrically conductive metal, designed to cut the insulation of a connecting conductor and make electrical contact with the conductor core. The recess also accommodates a longitudinally displaceable sliding element, which features a channel for a connecting conductor, aligned with a housing opening, and a recess for a tool, such as a screwdriver. The sliding element can be linearly displaced by a pivoting motion of the tool between a first position, which allows the conductor to be inserted into the channel, and a second position, in which the conductor is positioned up to the metal connecting piece.The clamp also features locking means in the form of complementary detent lugs to secure the sliding part in the first position.

[0014] DE 33 00 697 A1 describes a terminal block with a housing made of insulating material, which has two interior spaces through which a common metal contact piece passes. This contact piece has slot-shaped openings with cutting edges. A drive element, movable back and forth between two end positions, has a recess for receiving the end of an insulated conductor and passes through an opening in the contact piece. The drive element is pivotally mounted as a lever or slidably mounted in the housing as a slide, and allows the conductor to be forced into the slot-shaped opening so that the cutting edges cut through the conductor's insulation and make electrical contact.

[0015] US 6,048,223 A describes a terminal block with an insulating housing that has a recess in which a clamping jaw made of a conductive material and a sliding element made of a plastic material are arranged. The sliding element is guided longitudinally by the clamping jaw. The sliding element has a recess into which a tool end, e.g., a screwdriver blade, can be inserted to move the sliding element linearly. This movement pushes a conductor, which can be positioned between the sliding element and the conductive clamping jaw, toward the conductive clamping jaw and into a clamping slot therein. The slot insulates the conductor and establishes an electrical contact between the conductor and the conductive clamping jaw.

[0016] DE 29 02 526 B1 describes an electrical terminal block for electrical conductors with a connection in the manner of an insulation displacement connector, with a metal part provided with cutting edges on its conductor receptacle and an actuating element made of electrically insulating material arranged movably relative to this in a terminal housing, which is provided with guides designed as plug-in holes for an insulated conductor.

[0017] FR 2 611 406 A1 describes a self-insulating electrical terminal for electrical conductors with two openings for inserting and holding conductors, wherein the openings each have a corrugated area for fixing the conductor insulation when the conductors have been moved by a slider into a connection position in which they are in electrical contact with a cable lug.

[0018] It is therefore an object of the invention to overcome the shortcomings associated with self-insulating electrical terminals according to the prior art. In particular, it is an object of the invention to provide a self-insulating electrical terminal that enables reliable operation even when the terminal is subjected to strong vibrations or shocks during operation.

[0019] The invention therefore relates to a self-insulating electrical terminal block for electrical conductors, which has the features of independent claim 1. Particularly preferred further applications of the invention are the subject of dependent claims.

[0020] The terminal block according to the invention has a terminal housing in the interior of which two recesses are provided, and which has in each recess: - a fixed cable lug made of an electrically conductive material; and - a sliding part made of an electrically insulating material, wherein the sliding part is provided with an axial channel capable of receiving a conductor, wherein the sliding part is displaceable in the recess along an axis transverse to a direction of the introduction of the conductor into the slide between a first position which enables the introduction of the conductor into the channel or channels and a second position in which the conductor is brought up to the cable lug.

[0021] Furthermore, the terminal block has locking means designed to lock the respective sliding part in the first and second positions, each sliding part being mounted in such a way that it is linearly displaceable under the action of a pivoting movement of a tool.

[0022] The locking means (or detent devices) have means for snap-locking the sliding part in the terminal housing.

[0023] In particular, the locking means for each sliding part have a bead provided on the sliding part and two recesses provided in the terminal housing into which the bead engages in one and the other from the first and second positions, each sliding part having a recess provided to facilitate deformation of the sliding part in the vicinity of the bead in order to assist engagement and disengagement of the bead into and out of the recesses.

[0024] Each recess is associated with an opening for the insertion of a conductor, which is provided at the upper end of the terminal housing and leads to the associated recess, wherein the thickness at the upper end of the terminal housing is selected such that effective retention of the conductor is enabled without impairing its insulation.

[0025] Preferably, the terminal housing forms a clamping device for the conductor, so that external forces exerted on the conductor are transferred to the terminal housing in this way.

[0026] According to another feature of the terminal block, the axial channel is a channel closed on one side and has a bottom that forms a stop or abutment for the conductor.

[0027] According to a further feature of the terminal block, each opening is arranged in such a way that the opening is arranged coaxially to the channel in the first position.

[0028] It could be provided that each opening has a narrowing or reducing size in order to achieve an offset clamping of the conductor.

[0029] In one embodiment, each sliding part has a transverse slot that opens into the channel and is provided for the insertion of the respective cable lug in the second position.

[0030] According to a further feature of the terminal block, each sliding part has a cavity accessible from the outside of the terminal block via an opening provided in the terminal housing, the cavity being designed to accommodate a tool for adjusting the respective sliding part, the cavity being positioned at a height that is essentially the same as the plane of the cutting forces for insulating the conductor.

[0031] For example, each sliding part has a single cavity with a generally conical cross-sectional shape to facilitate tool insertion. This allows the tool to reach its actuating position in any position of the sliding part.

[0032] In one embodiment, each cable lug is mounted on a terminal plate, for example by folding or crimping, wherein the terminal housing has at least one axial passage opposite the terminal plate for the electrical connection of the terminal to another terminal.

[0033] For example, the terminal plate has through holes that can accommodate bridging terminals or shunts that connect the adjacent terminals.

[0034] It could be intended that the cable lugs are mounted on a common terminal plate.

[0035] Further tasks, features and advantages of the invention will become apparent upon reading the following description, which is provided solely for illustrative purposes, in no way limiting, and refers to the accompanying drawings, which show: - Fig. 1 a perspective view of a clamp according to the invention; - Fig. 2 a sectional view of the clamp according to Fig. 1. Illustrating the sliding part in the first position; - Fig. 3 a perspective view of the arrangement formed by the sliding part and the cable lug in the first position; - Fig. 4 a sectional view of the clamp according to Fig. 1. Illustrating the sliding part in the second position; - Fig. 5 a perspective view of the arrangement formed by the sliding part and the cable lug in the second position; - Fig. 6. A top view of the cable lug of the terminal. Fig. 1.

[0036] In Fig. Figure 1 illustrates a perspective view of a clamp generally designated by reference numeral 1 according to the present invention in a substantially vertical position.

[0037] As can be seen, the terminal 1 essentially has a terminal body or terminal housing 2, which has a lower end 3, which is provided with a leg, such as 4 and 5, which enables its mounting on a rail, and an upper end 6, which is provided with conventional label holders 7 in the side direction.

[0038] The clamp 1 is therefore designed to be mounted on a rail via legs 4 and 5. The legs are preferably adapted in such a way that the clamp can fit rails of different standards, for example according to DIN and NF standards.

[0039] In the example shown, terminal 1 is a self-insulating terminal block and is intended for connecting two conductors.

[0040] However, the scope of the invention is not left if such a terminal is provided for connecting a higher number of such conductors, for example for three or four conductors or even more.

[0041] Likewise, terminal 1 mounted on the rail is also designed to allow its connection with other terminals of the same type, as explained below.

[0042] In the illustrated embodiment, the upper end 6 of the terminal housing 2 has two openings 8 and 9, each of which is provided for the insertion of a connecting conductor.

[0043] As can be seen, each opening 8 and 9 has a first end 8a and 9a of greater width, which is chosen to allow the insertion of a conductor with play, and an opposite second end 8b and 9b which is narrower and able to hold the conductor by jamming.

[0044] It should also be noted that in this upper area the thickness of the terminal housing 2 is chosen in such a way as to allow effective retention of the conductor without impairing its insulation.

[0045] Referring to Fig. 2 it can be seen that the openings 8 and 9 each lead into a recess or a storage space 10 or 11, in which a sliding part 12, 13 and a self-insulating connecting piece in the form of a cable lug 14 and 15 are arranged.

[0046] The sliding part is positioned relative to a general longitudinal axis of terminal 1 between a first position, which is located in the Fig. 2 and Fig. 3 is visible and allows the insertion of a connecting cable, and a second longitudinal position which is located in the Fig. 4 and Fig. 5 is visible and in which the conductor is connected and simultaneously stripped under the action of the cable lug 14, 15, is longitudinally displaceable.

[0047] In other words, the sliding part 12, 13 in the recess 10, 11 is in the first position in which the sliding part 12, 13 rests against one end 16, 17 of the recess, which is directed towards the opposite side edges 18 and 19 of the terminal housing 2 ( Fig. 1) can be displaced to a second opposite end 20, 21 of the recess, which is opposite the first end 16, 17.

[0048] In this respect, the sliding part 12, 13 has a cavity 22, 23 which is accessible from the outside by means of a tool O via an opening 24, 25 which is provided in the housing body 2.

[0049] As can be seen, the cavity 22, 23 has a longitudinal dimension which, viewed along the general axis, is larger than the longitudinal dimension of the opening 24, 25.

[0050] As furthermore, from the Fig. 2 and Fig. As can be seen in Figure 3, this cavity has a substantially conical or tapered cross-section and comprises widening or obliquely running front and rear walls, such as 26 and 27.

[0051] Because of this device, it is possible to move the sliding part from the first and second positions using a tool O, such as a screwdriver, starting from one position or the other, by angularly adjusting or pivoting the tool O, which rests on the edge of the opening 24 on one side and is supported on the other side in a recess 28 formed in the bottom of the cavity 22 or 23.

[0052] It is also from the Fig. 2 and Fig. 4 can be seen that the sliding part 12, 13 has an axial channel 30, 31 which is provided with a bottom or base F which forms a support against which the conductor rests after its insertion into the sliding part.

[0053] Adjacent to the channel, the sliding part 12, 13 has a transverse slot 32, 33 which is oriented in the direction of movement of the sliding part in such a way as to allow the insertion of the cable lug 14, 15. On the side opposite the slot, the sliding part 12, 13 has a recess 34, 35 which is designed to receive one end of the cable lug in the second position of the sliding part.

[0054] The sled 12 is made of an electrically insulating material, for example plastic, in particular by injection molding.

[0055] The cable lug 14 is itself made of an electrically conductive material, for example metal, by bending a metal plate.

[0056] This is pressed onto a plate 36, which is located near the bottom 3 of the body 2.

[0057] This plate 36 is designed to accommodate the two cable lugs 14 and 15 of terminal 1 and to connect the connecting conductors in pairs parallel to each other.

[0058] As especially from Fig. As can be seen in Figure 3, the cable lug 14 or 15 has two elastically deformable legs, for example 37, the free ends 38 of which are bent over and arranged opposite each other.

[0059] Preferably, the bent end 38 of each leg has a front edge 39 which is cut such that the two legs in this area define a substantially V-shaped shape ( Fig. 6).

[0060] In this area, the inner edge of the cable lug 14, 15 is preferably sharply formed in order to achieve effective stripping of the conductors.

[0061] This sharp part can be obtained, for example, by providing the free ends 38 of the legs of the cable lug 14, 15 with a reduced cross-sectional thickness.

[0062] Finally, it should be noted that, as previously indicated, to enable a connection between different terminals, the terminal housing 2 is provided with axial passages, here two axial passages, such as 40, which provide access from the outside to the plate 36 on which the cable lugs 14 and 15 are mounted.

[0063] With the aim of ensuring that the sliding parts 12, 13 are locked in one and the other first and second position, the clamp is provided with locking or locking means.

[0064] These locking means act in such a way as to lock the sliding part in its two outermost positions. However, in a variant, without departing from the scope of the invention, locking means could of course be provided in such a way as to ensure the locking of the sliding part in one or the other outermost position.

[0065] In the illustrated embodiment, the body of the sliding part has a lower part which is provided with a bead or projection B, while the clamping housing 2 is provided in the base of each recess 10, 11 with two recesses or receptacles L and L' which are positioned in such a way as to receive the bead B in one and the other outermost position.

[0066] For example, as illustrated, the bead B is provided at one end of the sliding part, wherein a first receptacle L is provided in the bottom of the recess on the side adjacent to the end 16, 17 of the recess, while the other receptacle L' is provided at a substantially central location suitable to receive the bead B when the sliding part comes into contact with the other end 20, 21 of the recess.

[0067] To facilitate the deformation of the sliding part in the vicinity of the bead, a recess E is provided in the sliding part 12, which is arranged in such a way as to facilitate the engagement and disengagement of the bead B.

[0068] Due to the presence of these snap-lock devices, holding the sliding part is ensured, either in the first position to allow the insertion of a conductor, or in the second position to clamp the conductor firmly in the cable lug.

[0069] However, it should be noted that when the sliding part is moved, the conductor, which is previously inserted into the opening 8 in the terminal body, moves longitudinally inside this opening from the section with larger diameter 8a, 9a, in which the conductor is inserted with play, to the section with smaller diameter 8b, 9b, at the height of which the conductor is securely held.

[0070] Consequently, the holding of the conductor is essentially accomplished by the housing body, while the cable lug essentially only ensures its function of electrical connection and insulation stripping.

[0071] Consequently, even when the clamp is subjected to strong vibrations, the cable lug is subjected to little stress and is able to effectively fulfill its function.

[0072] Finally, by focusing in particular on the Fig. 2 and Fig. 4. Referring to section 4, the terminal just described can be used in the following manner.

[0073] Starting from the in Fig. In the position shown in Figure 2, where the sliding part 12, 13 is in the first position and held therein by means of the bead B, which is engaged in the corresponding receptacle L, a conductor is inserted through the opening 8 and, in particular, over the wider end 8a without prior stripping. In this position, the channel 30 is aligned with this end 8a and is an axial extension of this end 8a. It is thus easily visible from the outside. It also guides the conductor, which can therefore be inserted in a substantially vertical direction until it reaches the base F. The presence of the base ensures that a sufficient length of conductor is inserted into the clamp. After the conductor has been inserted, the sliding part 12, 13 can be easily removed from the Fig. 2 shown position from to the one in Fig.The visible position is moved so that the sliding part comes into contact with the end 20 of the recess and the bead B engages in the central recess L'. During its movement, the V-shaped front edge of the cable lug advances through the slot 32 into the interior of the channel 30 until it reaches the recess 34.

[0074] During its insertion, the sharp front end 39 of the cable lug locally cuts open the insulation of the conductor, ensuring both the stripping of the conductor and its electrical connection.

[0075] However, it should be noted that this stripping is carried out in such a localized manner that the insulation remains attached to the conductor. Consequently, after the conductor is removed, no insulation material will be left behind at the bottom of the recess.

[0076] After connecting the terminals, they can then be connected to each other, as previously indicated, using connecting elements such as riders or U-shaped connectors, which are inserted into the passages 40.

[0077] This self-insulating electrical terminal for electrical conductors has a terminal body 2 which is provided in its interior with at least one recess 10, 11, and has in each recess at least one fixed cable lug made of an electrically conductive material and at least one electrically insulating sliding part 12, 13 which is provided with at least one axial channel 30, 31 which is able to receive a conductor, wherein the sliding part is displaceable along a transverse axis in a direction of the insertion of the conductor between a first position for the insertion of the conductor and a second position in which the conductor is brought up to the cable lug.

[0078] The clamp has locking means B, L, L' which are configured to lock the sliding part in at least one of the first and second positions. Furthermore, the sliding part is mounted such that it is linearly displaceable under the action of a pivoting movement of the tool.

Claims

[1] Self-insulating electrical terminal block (1) for electrical conductors, comprising a terminal housing (2) in the interior of which two recesses (10, 11) are provided, and which has in each recess (10, 11): - a cable lug (14, 15) made of an electrically conductive material; - a sliding part (12, 13) made of an electrically insulating material, wherein the sliding part (12, 13) is provided with at least one axial channel (30, 31) capable of receiving a conductor, wherein the sliding part (12, 13) is displaceable in the recess (10, 11) along an axis that extends transversely to a direction of the introduction of the conductor into the sliding part (12, 13) between a first position which enables the introduction of the conductor into the or each axial channel (30, 31) and a second position in which the conductor is brought up to the cable lug (14, 15), and the terminal (1) has locking means (B, L, L') which are arranged to lock the respective sliding part (12, 13) in the first and second positions, wherein the locking means (B, L, L') for each sliding part (12, 13) have a bead (B) provided on the sliding part (12, 13) and two recesses (L, L') provided in the terminal housing (2) and into which the bead (B) engages in one and the other from the first and second positions, wherein each sliding part (12, 13) has a recess (E) provided to facilitate deformation of the sliding part (12, 13) in the vicinity of the bead (B) to assist engagement and disengagement of the bead (B) into and out of the recesses (L, L'), wherein each sliding part (12, 13) is mounted such that it can be linearly displaced under the action of a pivoting movement of a tool (O), wherein each recess (10, 11) for the insertion of a conductor is associated with an opening (8, 9) which is provided at the upper end (6) of the terminal housing (2) and leads to the associated recess (10, 11), wherein the thickness at the upper end (6) of the terminal housing (2) is selected such that effective retention of the conductor is enabled without impairing its insulation. [2] Terminal block (1) according to claim 1, characterized by , that the terminal housing (2) forms a device for clamping the conductor, so that consequently external forces exerted on the conductor are transferred to the terminal housing (2). [3] Terminal block (1) according to one of claims 1 or 2, characterized by , that the axial channel (30, 31) is a channel closed at one end and has a bottom (F) which forms a support for the conductor. [4] Terminal block (1) according to one of claims 1 to 3, characterized by, that each opening (8, 9) is able to receive the conductor, the opening in the first position being arranged coaxially to the axial channel (30, 31). [5] Terminal block (1) according to claim 4, characterized by , that each opening (8, 9) has a narrowing shape to achieve a laterally offset clamping of the conductor. [6] Terminal block (1) according to one of claims 1 to 5, characterized by , that each sliding part (12, 13) has a transverse slot (32, 33) which opens into the axial channel (30, 31) and is provided for the insertion of the respective cable lug (14, 15) in the second position. [7] Terminal block (1) according to one of claims 1 to 6, characterized by, that each sliding part (12, 13) has a cavity (22, 23) accessible from the outside of the terminal block (1) via an opening (24, 25) formed in the terminal housing (2), wherein the cavity (22, 23) is provided to accommodate a tool (O) for moving the respective sliding part (12, 13), wherein the cavity (22, 23) is arranged on a plane that substantially corresponds to that of the forces for cutting through the insulation of the conductor. [8] Terminal block (1) according to claim 7, characterized by , that each sliding part (12, 13) has a single cavity (22, 23) with a substantially conical cross-section to facilitate the insertion of the tool (O) in any position of the respective sliding part (12, 13) until it reaches its operating position. [9] Terminal block (1) according to any one of claims 1 to 8, characterized by, that each cable lug (14, 15) is mounted, for example, by crimping onto a terminal plate (36) and that the terminal housing (2) has at least one axial passage (40) opposite the terminal plate (36) for the electrical connection of the terminal (1) to another terminal (1). [10] Terminal block (1) according to claim 9, characterized by , that the two cable lugs (14, 15) are mounted on a common connection plate (36). [11] Terminal block (1) according to claim 10, characterized by , that the terminal plate (36) has through holes which can accommodate clamp-like bridging shunts which connect the adjacent terminals together. [12] Terminal block (1) according to one of the preceding claims, characterized by that it is designed to be mounted on a DIN-type or NF-type rail.

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