The instant invention relates to a terminal block for a cable connector comprising cavities for insulation displacement contacts. The invention also relates to a connector comprising such a terminal block.
An insulation displacement connectors are a connector that implement electrical contacts adapted to pierce or cut the insulation sheath on a cable to make the connection with the cable wire.
Such connectors typically comprise a housing or terminal block having short open-ended slots that receive corresponding insulation displacement contacts which contain sharp metal blades. These blades are adapted to cut through the insulation sheath of a cable when the latter is punched into the slot. These blades hold the cable in position and make electrical contact with the electro-conductive wire of the cable.
A punch tool or punch down tool is typically used to push the cable laterally (i.e. perpendicularly to the cable axis) into the slot. A suitable punch tool is disclosed in U.S. Pat. No. 5,099,570. To use the punch tool, a cable is inserted in between two metal blades of an insulation displacement connector and the punch tool is pressed down onto the cable and the two blades until the cable is stripped and electrical contact is made with the electro-conductive wire of the cable as it is pushed between the blades.
When a cable is punched laterally into an insulation displacement connector slot, a force is exerted onto the terminal block, which needs to be balanced. Otherwise the terminal block may be damaged. Particularly if the slot is close to a side end of the terminal block, the terminal block can bend under the action of the exerted punch force.
It is an object of the invention to provide a terminal block allowing punching of one or more cables without the need to use an additional support to balance exerted punch forces.
This object of the invention is achieved with a terminal block according to claim 1.
Where the terminal block has two paired slots at opposite sides, two cables can simultaneously be punched into the slots by a punch tool, having two punching extremities which can be moved towards and away from each other at the same time. The same punch tool can be used for punching a cable into an insulation displacement contact slot which is paired with a punch support at the opposite side of the terminal block. While one of the punch tool extremities acts on the cable, the other punch tool extremity acts on the punch support. This way, the punch forces are balanced and no bending moments are induced into the terminal block.
The punch support may for example be a bulge, integrally formed with the terminal block, having cylindrical wall parallel to the opposite insulation displacement contact and curved with a radius corresponding to the radius of a cable to be punched. For instance, the radius may be equal +/−10% of the radius of a cable to be punched. The terminal block may for example comprise a back bone plate or partition having the punch supports and insulation displacement contacts at both sides. According to a preferred embodiment, the largest distance between the cylindrical wall of the punch support and the back bone plate corresponds to the largest distance between the punched cable and the back bone partition.
The terminal block may for example comprise at both sides a row of insulation displacement contact slots with a punch support between each pair of insulation displacement contact slots. Each punch support may be paired with an insulation displacement contact slot at the opposite side of the terminal block.
Optionally, one or more of the punch supports may be provided with a curved punch surface. The punch surface may for example be curved with a radius corresponding to the radius of a cable to be attached. This way, a punch tool can be used having two extremities movable in line with each other, the extremities having concave contact faces, which can act on either a cable to be punched or onto the punch support. This provides a better punching contact between the punch tool and the cable or the punch support.
The aforementioned object of the invention is also achieved with a cable connector comprising one or more terminal blocks as disclosed.
The aforementioned object of the invention is also achieved with a method of punching a cable into an insulation displacement contact slot in a terminal block of a cable connector, using a punch tool having a first extremity pushing the cable into the slot, while a second extremity of the punch tool acts on an opposite side of the terminal block to balance the exerted forces.
The present invention will be further explained with reference to the figures wherein:
With reference to
The insulation displacement contacts 5 have two pairs of sharp metal blades 8 which are adapted to cut through the insulation sheath of a cable when it is punched into the insulation displacement contact 5. These blades 8 hold the cable in position and make electrical contact with the electro-conductive core of the cable. The metal blades 8 are operatively connected to further electronic circuitry (not shown).
The insulation displacement contact slots 5′, located in coordinate (R1,C1), is positioned opposite to a punch support 6 formed in the insulation displacement contact slot 5′ located in coordinate (R2,C1). The punch supports 6 are formed as a longitudinal bulge parallel to the insulation displacement contact slots 5′. The punch supports 6 have a cylindrical surface with a radius r3 corresponding substantially to the radius r2 of a cable 10.
The largest distance L2 between the cylindrical wall of the punch support and the back bone plate 2 corresponds to the largest distance L1 between the punched cable 10 and the back bone partition 2.
It is to be understood that even though the characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in details, especially in matters of shape, size, and arrangement of the parts. For instance, the punch support 6, above described may be an appropriate removable plug that could be inserted or maintained in a wire and contact cavity, or in any other feature, of the terminal block. Advantageously, plugs of this kind allow customization of the cabling or wiring.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/IB2008/055687 | 12/19/2008 | WO | 00 | 6/17/2011 |