GB1589648A

GB1589648A - Electrical terminal unit

Info

Publication number: GB1589648A
Application number: GB2008178A
Authority: GB
Original assignee: CA Weidmueller GmbH and Co
Current assignee: Weidmueller Interface GmbH and Co KG
Priority date: 1977-05-28
Filing date: 1978-05-17
Publication date: 1981-05-20
Also published as: DE7717019U1

Description

(54) ELECTRICAL TERMINAL UNIT (71) We, C. A. WEIDMijLLER KG., a German company of Postfach 950, 4930 Detmold, Germany, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to electrical terminal units. The invention has particular but not exclusive application to block terminal units incorporating isolating members for selectively connecting and disconnecting terminals of the terminal unit.

Terminal units of the last mentioned kind are well known. Hitherto, they have in general been constructed with current-carrying bars each supporting a terminal, for example a screw-clamping sleeve, at. one end, and forming at the other end a web for engaging the isolating member. The bars are commonly provided with means for connection of a test probe, comprising a screw threaded bore in which is screwed a bush which serves as the socket for a test probe. This construction is comp]icated and expensive.

The present invention resides in an electrical terminal unit, comprising a one-piece sheet metal current-carrying component incorporating a terminal region and a web extending therefrom, the terminal region having two channels formed integral therewith for receiving respective conductors, and the web having a socket for a test probe which socket is formed by adjacent portions of the web arcuately deformed in opposite directions; a leaf spring located by members integral with the terminal region which spring is arranged to clamp conductors in respective channels of the terminal region and at least one further terminal electrically connected or connectable to the web.

Such a terminal unit is simple and cheap to manufacture. In particular the current-carrying component can be made from sheet metal in a single operation by blanking and bending or embossing, in a very simple and cheap manner.

Furthermore the previously necessary step of screwing in a test socket is eliminated. The use of portions of the current-carrying member itself as the test socket has the further advantage that the inherent resilience of the sheet metal ensures good contact with an inserted probe, and the effective surface areas of these portions for contact with the probe are at least comparable with those of the conventional socket bushes.

The use of a leaf spring as the conductorclamping element also simplifies construction.

A common spring is sufficient for both termina channels and the spring can be installed very simply, in the manner of a spring clip.

The terminal unit embodying the invention is shown in the accompanying drawings, in which: Figure 1 shows an isolating block terminal unit inside view, Figure 2 is a cross section on the line II-II in Figure 1, and Figure 3 is a perspective view of a currentcarrying component of the terminal unit.

The terminal unit shown in Figure 1 has a generally slab-shaped insulating casing 1 designed to be clipped onto and unclipped from a channel-section supporting rail 11.

The casing is open on one major side face for insertion of the terminal components during assembly. In use, this face is covered by the casing of an adjacent terminal unit or a cover plate.

The terminal unit contains two pairs of terminals for receiving respective conductors 4, and a pivotable isolating member 6 by means of which the pairs of terminals can be connected or disconnected.

Each pair of terminals is formed by a current-carrying component 2 formed in one piece by blanking, bending and embossing sheet metal.

A current-carrying component is shown in Figure 3. It includes a pair of substantially parallel channels 3 open on the sides facing one another and each of a deep prismatic cross section, specifically a V-section as shown in Figure 2. The conductors rest sufficiently deeply in the channels so that they bear not only in the top edge region of the channels cross section but, owing to the prismatic shape, are guided relatively deeply into the opening of the prism on being inserted so that they are in contact with both surfaces of the prism.

The region incorporating the terminal channels is integral with a sheet metal web 5.

The current-carrying components are placed symmetrically in the insulating casing, with the webs 5 extending towards one another for engaging respective portions of the isolating member. Each web has an integral test socket formed by first and second edge regions 7a deformed into semi-circles projecting both in the same direction from the plane of the web, and an intermediate central portion 7b deformed into a semi-circle projecting from the said plane in the opposite direction. Owing to the inherent properties of the sheet metal, these portions form a resilient socket of large contact surface area for receiving a test plug or probe inserted through an aperture 12 (Figure 1) in the insulating casing.

Each pair of terminals is associated with a respective common leaf spring 8 in the manner described and claimed in our co-pending application No. 20082/78. The spring is generally W-shaped with a central substantially semicircular bend 8a, respective adjoining limbs extending to respective oppositely disposed and oppositely curved almost-semi-circular bands 8b, and free limbs 8c extending from the latter towards the open sides of respective cages, obliquely with respect to the longitudinal directions of the latter. The free limbs therefore clamp conductors inserted in the channels, the obliquity thereof facilitating insertion and resisting withdrawal of the conductors.

The terminal region of each current-carrying part 2 has an integral hook shaped retaining lug 9 on which the central bend of the spring 8 is secured by an opening in the latter.

Between the other bends 8b of the spring is a support or abutment lug 10 integral with the said terminal region, for preventing either of the further bends of the spring from moving away from the associated channel. This ensures that manipulation of one free limb of the spring will not affect the other free limb or any conductor clamped thereby, The leaf spring is installed by being pushed between the channels until its central opening fits over the hook-shaped lug 9.

The channels may have integral flanges 13 along their edges remote from the main sheet metal part, as shown in broken lines in Figure 2.

Although the invention has been described with reference to an isolating terminal or substantially symmetrical construction, it is to be understood that the responsive current-carrying components can alternatively be permanently interconnected or even integral with one another. On the other hand it is not necessary that a second identical current-carrying component be provided, other forms of terminal being also possible.

WHAT WE CLAIM IS: 1. An electrical terminal unit, comprising a one-piece sheet metal current-carrying component incorporating a terminal region and a web extending therefrom, the terminal region having two channels formed integral therewith for receiving respective conductors, and the web having a socket for a test probe which socket is formed by adjacent portions of the web arcuately deformed in opposite directions; a leaf spring located by members integral with the terminal region which spring is arranged to clamp conductors in respective channels of the terminal region; and at least one further terminal electrically connected or connectable to the web.

2. A terminal unit as claimed in Claim 1 having two said further terminals comprising channels of a current-carrying component substantially identical to and symmetrically disposed with respect to the first-mentioned current-carrying component and provided with a further leaf spring.

3. A terminal unit as claimed in Claim 2 in which the said current-carrying components are separate from one another and in which a movable isolating member is provided for connecting and disconnecting the webs.

4. A terminal unit as claimed in Claim 1, 2 or 3 in which the said socket is formed by first and second portions adjoining respective edges of the web and both deformed in a first direction from the plane of the web, and an intermediate portion, between the first and second portions, deformed in the opposite direction from the plane of the web 5. A terminal unit as claimed in Claim 1, 2 3 or 4 in which each channel has a prismatic, deep, cross section, 6. A terminal unit as claimed in any preced ing claim, in which the or each leaf spring has a substantially central bend received on a first member integrally formed on the associated terminal region, respective limbs extending from each side of the said bend to respective further oppositely curved bends, and respective free limbs extending from the further bends obliquely towards respective channels; and in which the further bends adjoin an abutment member being integrally formed on the terminal region.

7, An electrical terminal unit substantially as herein described with reference to the accompanying drawings

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. The current-carrying components are placed symmetrically in the insulating casing, with the webs 5 extending towards one another for engaging respective portions of the isolating member. Each web has an integral test socket formed by first and second edge regions 7a deformed into semi-circles projecting both in the same direction from the plane of the web, and an intermediate central portion 7b deformed into a semi-circle projecting from the said plane in the opposite direction. Owing to the inherent properties of the sheet metal, these portions form a resilient socket of large contact surface area for receiving a test plug or probe inserted through an aperture 12 (Figure 1) in the insulating casing. Each pair of terminals is associated with a respective common leaf spring 8 in the manner described and claimed in our co-pending application No. 20082/78. The spring is generally W-shaped with a central substantially semicircular bend 8a, respective adjoining limbs extending to respective oppositely disposed and oppositely curved almost-semi-circular bands 8b, and free limbs 8c extending from the latter towards the open sides of respective cages, obliquely with respect to the longitudinal directions of the latter. The free limbs therefore clamp conductors inserted in the channels, the obliquity thereof facilitating insertion and resisting withdrawal of the conductors. The terminal region of each current-carrying part 2 has an integral hook shaped retaining lug 9 on which the central bend of the spring 8 is secured by an opening in the latter. Between the other bends 8b of the spring is a support or abutment lug 10 integral with the said terminal region, for preventing either of the further bends of the spring from moving away from the associated channel. This ensures that manipulation of one free limb of the spring will not affect the other free limb or any conductor clamped thereby, The leaf spring is installed by being pushed between the channels until its central opening fits over the hook-shaped lug 9. The channels may have integral flanges 13 along their edges remote from the main sheet metal part, as shown in broken lines in Figure 2. Although the invention has been described with reference to an isolating terminal or substantially symmetrical construction, it is to be understood that the responsive current-carrying components can alternatively be permanently interconnected or even integral with one another. On the other hand it is not necessary that a second identical current-carrying component be provided, other forms of terminal being also possible. WHAT WE CLAIM IS:

1. An electrical terminal unit, comprising a one-piece sheet metal current-carrying component incorporating a terminal region and a web extending therefrom, the terminal region having two channels formed integral therewith for receiving respective conductors, and the web having a socket for a test probe which socket is formed by adjacent portions of the web arcuately deformed in opposite directions; a leaf spring located by members integral with the terminal region which spring is arranged to clamp conductors in respective channels of the terminal region; and at least one further terminal electrically connected or connectable to the web.

4. A terminal unit as claimed in Claim 1, 2 or 3 in which the said socket is formed by first and second portions adjoining respective edges of the web and both deformed in a first direction from the plane of the web, and an intermediate portion, between the first and second portions, deformed in the opposite direction from the plane of the web

5. A terminal unit as claimed in Claim 1, 2 3 or 4 in which each channel has a prismatic, deep, cross section,

6. A terminal unit as claimed in any preced ing claim, in which the or each leaf spring has a substantially central bend received on a first member integrally formed on the associated terminal region, respective limbs extending from each side of the said bend to respective further oppositely curved bends, and respective free limbs extending from the further bends obliquely towards respective channels; and in which the further bends adjoin an abutment member being integrally formed on the terminal region.