Metallic components

The “clamping yoke system”

The purpose of a clamping system is to keep the connection electrically and mechanically efficient.

The specific design and the right dimensioning of the metallic components take care of the following factors:
– kind of materials;
– shape and treatments of contact surfaces;
– steady contact pressure.

The design of the “clamping yoke system” takes into consideration the specific steel, copper and brass properties, making available an optimal coupling system: in fact, even the best conductive materials supply restricted performances if there is no enough contact pressure.

The yoke, made of tempered steel, tightens the conductor to the leading bar by means of a screw that provides a high contact power; a long lasting contact is obtained thanks to wide contact surface and to strong forces available even applying low clamping torques.

Three several incisions, designed in the bottom part of the yoke and crossing the direction of conductor insertion, make available an unique mechanical clamping system resistant to the flexion test (dynamic test) and to the pull-out test (static test), in compliance with product’s approvals (IEC 947-1): laboratory tests confirm the efficiency of the adopted solution which doesn’t affect the characteristics of the conductor, that can be used without pre-treatment (cable lug) also.

While a terminal block is clamped, the rifling done over the conductive bar guarantees a perfect contact with an even oxidized conductor, carving and increasing its contact surface.
Its unique section, flat for small conductors and concave for those are bigger (fig. 2), allows the large connecting capacity that characterize ASI terminal blocks to be utilized even with conductors having section smaller than rated section, in compliance with the referring Standards.

description of working principle

When the right clamping torque (as reported in official Standards) is applied, the force obtained gets the elastic double treaded system of the stirrup (fig. 3) deformed on the screw.
Even further thermical transitions are compensated by clamping stirrup elastic response.
Due to that, behavior further screw clamping operations are unnecessary.

For a fast utilization every terminal is provided with the clamping system in open position; furthermore, a metallic slider doesn’t allow erroneous conductor insertion while an insulating wall inside the polyamide frame bounds the conductor clamping position.

Regarding the insulation stripping length, is a must to follow the technical regulations reported in technical product file, to avoid wrong stripping operations compromising the insulating level.
Furthermore the following characteristics are guaranteed:

– aggressive atmospheric agent resistance, result of specific zinc-plated and passivated processes, optimized over the past years by a proven experience done on million pieces;

– heavy metal absence (RoHS Directive – 2011/65/EU) like:
Lead (Pb)
Mercury (Hg)
Cadmium (Cd)
Hexavalent chromium (Cr 6+)