GB2114824A

GB2114824A - Electrical terminal

Info

Publication number: GB2114824A
Application number: GB08303085A
Authority: GB
Inventors: Hans Woertz
Original assignee: WOERTZ FA
Current assignee: WOERTZ FA
Priority date: 1982-02-10
Filing date: 1983-02-04
Publication date: 1983-08-24
Also published as: GB2114824B; GB8303085D0; JPS5927077B2; FR2521356B1; JPS58175270A; FR2521356A1; CH653813A5; DE3300697A1; DE3300697C2

Abstract

At least one entraining body (28, 29) is arranged for movement between two end positions in a housing (10). The entraining body (28, 29) is provided with a recess (32, 33) for the reception of an end portion of an insulated conductor and projects through a passage (22, 23) in a contact member (15). The latter has at least one slit-shaped opening (24, 25) which has blade-like edges and an enlarged aperture (26, 27) into which the passage (22, 23) goes. The part (15A) of the contact member (15) containing the slit-shaped opening (24, 25) and the enlarged aperture (26, 27) engage in a mouth-like notch (34, 35) of the entraining body (28, 29). At least one part (33B) of the recess has a closed peripheral wall. In one end position of the entraining body (28, 29) an insulated conductor can be inserted into the recess (32, 33). By means of a subsequent movement of the entraining body (28, 29) to its other end position the conductor will be forced into the slit- shaped opening (24, 25) whereby the blade-like edges of the slit-shaped opening (24, 25) cut through the insulation and make contact with the conductor. In desired cases, the conductor may again be separated from the contact member by moving the entraining body (28, 29) in the opposite direction. <IMAGE>

Description

SPECIFICATION Electrical terminal The present invention concerns an electrical terminal which permits at least one insulated electrical conductor to be connected without the need for first stripping the insulation from an end piece of the conductor. More precisely stated, the invention concerns an electrical terminal comprising a housing to be secured to a stationary carrier and at least one contact member arranged in the housing, the contact member having at least one slit-shaped opening with two mutually oppositely lying blade-like edges for cutting through the insulation of an electrical conductor and for making contact with the conductor as well as an enlarged aperture at one end of the bladelike edges, and at least one entraining body which is displaceable in a direction at least approximately parallel to the blade-like edges of the contact member in order to bring the conductor into engagement with the said edges.

An advantage of a terminal of such a type lies not only in that the stripping of insulation of the electrical conductor to be connected is obviated but also in that the tightening of a terminal or clamp screw is dispensed with and thus the connection of the conductor can be undertaken more rapidly than with other terminals.

The task of the invention is so to improve an electrical terminal of the above-mentioned kind that one end part of an insulated electrical conductor can be brought into engagement with the blade-like edges of the contact member conveniently, reliably and safely and without deforming it along its longitudinal axis and in given cases can also be disengaged again therefrom.

This task is solved by an electrical terminal as defined in the Claims.

Details and advantages of preferred embodiments of electrical terminal assemblies according to the invention are given in the following description of the preferred embodiments and the associated drawings.

Figure 1 shows a twin terminal block constructed according to the invention, partly in side view and partly in section along the line I-I in Figure 2; Figure 2 is a view of the terminal block, as seen from the left in Figure 1; Figure 3 represents the cross-section taken along the line Ill-Ill in Figure 1; Figure 4 is a view Qf a contact member of the terminal block; Figure 5 is a partial view analogous to Figure 1 but showing a second preferred embodiment of the electrical terminal according to the invention; and Figure 6 shows a view of the same terminal, as seen from the left in Figure 5.

The electrical terminal block shown in Figures 1 to 4 comprises a housing 10 made of insulating material which is provided in a known manner with two retaining feet 11 and 1 2 for securing the terminal block on a non-illustrated fixed carrier rail. The housing 10 contains two spaces 1 3 and 14 which are formed and arranged in mirror symmetry relative to each other and which are open towards one flat side of the housing (to the right in Figure 2) and towards an end face remote from the retaining feet (to the left in Figure 1).The two spaces 1 3 and 14 are traversed through by a common metallic contact member 1 5 which is essentially a straight, profiled member of Ushaped cross-section with a level web 1 5A of the U from which two shanks 1 5B and 1 5C of the U each extend at right angles. The mutually oppositely lying end parts of the contact member 1 5 are journalled in matching recesses 1 6 and 17 of the housing, while the central part of the contact member rests in a recess 18 of the housing. as may be seen clearly in Figure 1. If desired, the contact member 1 5 may be coupled to a non-illustrated transverse connecting conductor by means of a screw 1 9 which projects through a bore 20 of the housing and is screwed into a threaded bore 21 (Figure 4) in the central part of the contact member 1 5.

The web 1 5A of the U of the contact member 1 5 has two relatively large through-going passages 22 and 23 (Figure 4) which extend transversely of the contact member from one of the shanks 1 5B of the U to the other shank 15C of the U. In the web 1 5A of the U, each end part of the contact member 1 5 is provided with a respective slit-shaped opening 24 and 25 going over into a respective apertures 26 and 27, which widens out in a funnel-like manner to go over into the apertures 22 and 23.Each of the slit-shaped openings 24 and 25 is bounded by two parallel blade-like edges 24A, 24B and 25A, 25B respectively, which extend longitudinally of the contact member 1 5 and are intended to cut through the insulation of an insulated conductorto be coupled to the terminal assembly and to make contact with the conductor, as will be described below.

A respective displaceable entraining body 28 and 29 is disposed in each of the two spaces 13 and 14 of the housing 10, projects through the respective passages 22 and 23 of the contact member 15 and is pivotally journalled in the housing 10 by means of a respective pin 30 and 31. The pins 30 and 31 extend perpendicularly to the blade-like edges 24A, 24B and 25A,25B of the slit-shaped openings 24, 25 at an appreciable distance from the web 1 5A of the U of the contact member 15, and moreover on the side of the contact member facing the retaining feet 11, 12.

Expediently, the pins 30 and 31 are formed of one piece with the housing 1 0. Each entraining body 28 or 29 has a recess 32 or 33, respectively, for the reception of an insulated conductor, the recess extending approximately radially to the associated pins 30, 31, respectively, and being open at the end of the entraining body remote from the pins.

From Figure 1 it may be seen clearly that the recess 33 in the entraining body 29 is partly of the shape of an open groove 33A and partly of the shape of a bore 338 with a closed peripheral wall and with a closed end 33C for limiting the depth of insertion of the insulated conductor. The recess 32 in the other entraining body 28 is of mirror-like identical construction. Each of the entraining bodies 28 or 29 further includes a mouth-like notch 34,35, respectively, in which engages, with sufficient play, the part of the U-web 15A of the contact member 1 5 which includes the slitshaped opening 24 or 25 and the enlarged aperture 26 or27, so that the pivoting movement of the entraining body is not impeded.From Figures 1 and 3 it may be seen that the recess 33 or 32, respectively, of each entraining body extends to the two sides of the U-web 1 5A of the contact member 1 5.

The entraining bodies 28 and 29 are each pivotable between a first and a second end position. In Figures 1 and 2 one of the entraining bodies 29 is in the first end position and the other entraining body 28 is shown in the second end position. When the entraining bodies 28 and 29 are in the first end positions, the recess 32 or 33 is in registry with a position lying in the region of the enlarged opening 26 or 27, at one end of the slitshaped opening 24 or 25 of the contact piece, so that an insulated conductor may be introduced without hindrance into the recess 32 or 33 up to the enclosed end 32C or 33C of the latter.Should, however, the entraining bodies 28 or 29 be in the second end position, then the recess 32 or 33 is in registry with a position lying between the bladelike edges 24A, 248 and 2 5A, 25B of the slitshaped opening 24,25 near to the closed end of the latter, as can be seen clearly in Figure 2 in the case of the entraining body 28.

The two end positions of each entraining body 28, 29 are determined by associated abutments.

To fix the first end position of each entraining body 28 or 29 an abutment cam 36 or 37 is provided within the relevant space 13 or 14 of the housing 10.

The second end position is fixed by abutment of the inner end of the mouth-like notch 34, 35, respectively, of the relevant entraining body 28, 29, respectively, against steps or shoulders 38, 39, respectively, (Figure 4) of the contour of the enlarged aperture 26, 27, respectively.In other respects the spaces 1 3, 1 4 in the housing 10 are so dimensioned that in both in the first end position and the second end position of the relevant entraining body 28, 29 an intermediate space 40, 41, respectively, is left free between the entraining body and the adjacently lying transverse wall of the space 13, for the introduction of a rod-like auxiliary tool, e.g. a screwdriver, with the aid of which the entraining body can be forced into the opposite end position, whereby the tool serves as a lever.

A respective small toggle 34, 35 is pivotally journalled with the aid of a respective hinge pin 42, 43 at that end part of the entraining body 28, 29 which is remote from the pivot pins 30, 31, the toggles serving as locking members to secure the relevant entraining body 28, 29 in its second end position, as is shown in Figure 1 for the entraining body 28. By pivoting the toggle 44, 45, the free end of the toggle remote from the hinge pin 42 or 43 can be brought into and out of engagement with a respective detent recess 46, 47 in the adjacent transverse wall of the space 13, 14 accommodating the relevant entraining body 28, 29. To facilitate its actuation, each toggle 44 or 45 is provided with an essentially hammer-shaped actuator 48 or 49.

The mode of utilisation and operation of the terminal block described above is as follows:- Let it be assumed that the terminal is secured on a fixed carrier rail by means of the retaining feet 11, 12 of the housing 10 and that the electrical conductors to be coupled to the terminal assembly each have a diameter somewhat exceeding the width of the slit-shaped openings 24, 25 in the contact member 1 5. Accordingly, the insulation of the conductor has a larger outer diameter. To prepare the connection of an electrical conductor to the blade-like edges 25A, 25B of the opening 25 of the contact member 15, the toggle 45 is pivoted to its inoperative position shown in the lower part of Figure 1 and then the entraining body 29 is pivoted into its first end position, according to the view in Figure 1.Then the recess 33 of the entraining body 29 is in alignment with a position lying in the region of the enlarged aperture 27 of the slit-shaped opening 35 of the contact member 1 5. Then without first stripping of its insulation the electrical conductor to be coupled is introduced into the recess 33, and more particularly until the leading end of the insulated conductor abuts against the closed end 33C of the recess 33. Then a rod-like tool, e.g. a screwdriver, is inserted into the intermediate space 41 between the entraining body 29 and the adjacent transverse wall of the space 14 and using this tool as a lever the entraining body 29 is pressed into its second end position.In this way, the insulated conductor is forced into the enlarged opening 27 and then into the slit-like opening 25 of the contact member 1 5, the movement of the conductor during this time occurring in a direction approximately parallel to the blade-like edges 25A, 25B of the slit-shaped opening. In this way the blade-like edges 25A, 25B cut transversely through the insulation of the conductor so that the conductor, now stripped, is brought into contact at these positions with the said edges. Since the insulated conductor is guided in the recess 33 of the entraining body 29 any bending or deformation of the conductor during its being forced into the slit-shaped opening 25 is prevented. When the diameter of the conductor is only a little larger than the width of the slit-shaped opening 25 there arises a small transverse deformation or pinching of the conductor, whereby the electrical contact with the contact member 15 is enhanced. Then, to secure the entraining body 29 in the last-mentioned second end position the toggle 45 is changed over to its second locking position and brought into engagement with the detent recess 47 in the housing 1 0, analogously to the position of the toggle 44 represented at the upper part of Figure 1.

In a fully analogous manner, a second insulated conductor may be brought into contact with the blade-like edges 24A, 248 of the other slit-shaped opening 24 of the contact member 1 5, wherein the second conductor is introduced into the recess 32 of the entraining body 28 and thereafter by pivoting the entraining body 28 the conductor is forced into the slit-shaped opening 24. In this way, an electrical connection is formed between the two conductors, each connected to the contact member 1 5.

The above-described electrical terminajenables the connected conductor to be released from the contact member 15 and to be separated from the terminal. To release one of the conductors in contact with the edges 24A, 24B of the slitshaped opening 24, the toggle 44 serving as a locking member is brought out of engagement with the detent recess 46 by means of the actuator 48 and pivoted to an inoperative position.

Then a rod-like auxiliary tool, e.g. a screwdriver, is inserted into the intermediate space 40 between the entraining body 28 and the adjacent transverse wall of the space 1 3 and thereafter by means of the said tool the entraining body 28 is forced in the opposite end position, during which the tool is used as a lever. In this way. bv means of the closed peripheral wall of the internal part 32B of the recess 32 present in the entraining body 28, the electrical conductor is pushed out of the slitlike opening 24 into the enlarged aperture 26 and thus out of engagement with the blade-like edges 24A, 24B of the opening 24. Finally, the conductor can be pulled out of the recess 32.One proceeds in an analogous manner with the conductor in contact with the other slit-shaped opening 25 and its edges 25A, 258 to release and remove it.

It will be seen that both the connecting as well as the releasing of insulated conductors can be carried out simply, rapidly and in a trouble-free manner, and in which it is not necessary either to remove a part of the insulation orto actuate clamping screws.

In a non-illustrated variant of an embodiment of the above-described electrical terminal, each of the entraining bodies 28, 29 is provided with an additional recess running essentially parallel to the recess 32,33, respectively, and serving for the insertion of a rod-like tool, e.g. a screwdriver, with the aid of which the displacement of the entraining body from the first to the second end position and vice versa can be carried out.

A second preferred embodiment illustrated in Figures 5 and 6 of the terminal according to the invention differs from that described with reference to Figures 1 to 4 essentially as follows: The toggle 44 serving as a locking member at the pivotable entraining body 28 is omitted. In its place the entraining body 28 is provided with a resiliently bendable extension 50, the free end of which is provided with a head 51 shaped as a hook. A recess 52 and a tooth 53 are formed at the housing in such a manner that the head 51 of the extension 50 can engage into the recess 52 and thus can be brought into locking engagement with the tooth 53 when the entraining body 28 is pivoted into its second end position, as shown in Figure 5. Each of the head 51 and the tooth 53 has a respective oblique sliding surface 54, 55, respectively.These sliding surfaces 54, 55 are intended for co-operation with each other in order to guide the head 51 over the tooth 53 while the extension is deformed against its own resilient bias while the entraining body 28 is pivoted to its end position shown in Figure 5. As soon as the end position of the entraining body is reached, the head 51 snaps into position automatically behind the tooth 55 under the influence of the resilience of the extension 50 whereby the entraining body is locked or blocked in its end position. Reverse pivoting of the entraining body 28 is possible only after the head 51 is brought out of engagement with the tooth 53 against the resilient bias of the extension 50, e.g. with the aid of a screwdriver or the like, which is introduced into the recess 52 and pushed under the head 51.

In a fully analogous manner, the other pivotable entraining body 29 (not shown in Figures 5 and 6) may also be provided with a similar resilient extension which can be brought into locking engagement with an associated tooth on the housing lOin order to lock the entraining body 29 in its second end position.

It will be clear that the toggles 44, 45 or the resilient extension 50 serving as locking members may be arranged on the housing 10 instead of being arranged on the entraining bodies 28, 29 so that they can be brought into engagement with a counterpart on the entraining bodies 28, 29 in order to lock the entraining bodies in their second end positions.

In given cases the pivotally journalled entraining bodies 28, 29 may be replaced by entraining bodies formed as slides which are journalled for reciprocal sliding movement in the housing 10.

Finally, it is to be mentioned that a preferred embodiment of the terminal according to the invention may be useful and expedient wherein there is only one entrainment body, such as 28. or 29. In this case, the second circuit connection to the contact member 1 5 must be achieved in a different manner.

Claims

1. An electrical terminal comprising a housing to be secured on a stationary carrier, at least one contact member arranged in the housing, said at least one contact member including a siit-shaped opening defined between two mutually oppositely lying blade-like edges for cutting through the insulation of an electrical conductor and for making contact with the conductor, an enlarged aperture at one end of the two blade-like edges, and at least one entraining body which is guided in said housing for reciprocating displacement in a direction generally parallel to the blade-like edges in order to bring the conductor into engagement with the said edges, a recess defined in said at least one entraining body serving to accommodate an end portion of the insulated conductor, the recess extending generally perpendicularly to a plane comprising the two blade-like edges, abutment means defining two end positions for the said reciprocating displacement so that in the first of said end positions the said recess is in alignment with the said enlarged aperture at said one end of the blade-like edges while in the second of said end positions the said recess is in alignment with a portion of said slit-shaped opening adjacent the other end of and between the said blade-like edges.

2. Electrical terminal according to claim 1 wherein, for the reception of a conductor, the said recess is provided over at least a portion of its length with a closed peripheral wall in order to enable the conductor to be disengaged from the blade-like edges by a corresponding movement of the said entraining body.

3. Electrical terminal according to claim 1 or 2 wherein a locking member is provided for the releasable locking of the said entraining body in said second end position.

4. Electrical terminal according to claim 3 wherein the said locking member is a toggle pivotally journalled at the entraining body and has a free end that is engageable with and disengageable from a portion of the said housing.

5. Electrical terminal according to claim 3 wherein the locking member is a resiliently bendable extension of one of said housing and said entraining body, said extension having a free end, a hook-like head at said free end which is lockingly engageable with an associated counterpart at the other of said housing and said entraining body, whereby under the bias of the resilience of the extension the locking engagement takes place automatically as soon as the entraining body takes up its second end position.

6. Electrical terminal according to claim 1 or 2 wherein the entraining body is pivotally journalled in the housing by way of a pivot pin which extends at a distance from and at right angles to the said blade-like edges.

7. Electrical terminal according to claim 1 or 2 wherein the entraining body extends on both sides of a part of the said contact member, which includes the said slit-shaped opening and the said enlarged aperture, said entraining body having a mouth-like notch in which the said part of the contact member engages.

8. Electrical terminal according to claim 7 wherein the entraining body projects through a passage of the said contact member, which passage borders on the said enlarged aperture and, taken in the direction parallel to the blade-like edges, is dimensioned so as to be sufficiently large to permit the necessary displaceability for the entraining body.

9. Electrical terminal according to claim 8 wherein, regarded in a direction parallel to the blade-like edges, the contact member is of Ushaped cross-section, the said slit-shaped opening, the said enlarged aperture and the said passage through which the entraining body projects being arranged in the web part of the Ushaped contact member and the said passage extending from one to the other of the two limbs of the U.

10. Electrical terminal according to claim 1 or 2 wherein the said recess is closed at one of its ends in order to limit the depth of insertion of the conductor.

11. Electrical terminal according to claim 1 or2 wherein in each of said end positions of the entraining body there is defined between the entraining body and a part of the housing an intermediate space for the introduction of a rodlike tool, particularly a screwdriver, with the aid of which the movement of the entraining body between its ends positions can be effected.

12. Electrical terminal according to claim 1 or2 wherein a second recess is defined in said entraining body for the insertion of a rod-like tool, especially a screwdriver, with the aid of which the movement of the entraining body can be effected.

13. Electrical terminal substantially as herein described with reference to and as shown in Figures 1-4 or Figures 5 and 6 of the accompanying drawings.