Schroff presents the new Card-Lok series 223 and 224 board retainers from the product range of sister company Calmark, also a member of the Pentair Technical Products Group. Card-Loks are used to secure printed circuit boards (PCBs) in place. The new series includes a torque limiting feature, for which a patent has been filed, so that PCBs can be mounted into a chassis with a predetermined clamping force and without the need for a torque wrench.

The new Card-Loks, with five wedge elements, are intended primarily for defence applications and for those in aviation and space travel. They are designed to prevent damage being caused to the board or to the Card-Lok itself through overtightening. Turning the central screw clockwise draws the outer wedges together, forcing an outward extension of the middle wedge sections. When the torque force applied to the screw reaches the preset value, the built-in pawl coupling is released with an audible click. This prevents any further tightening.

The Card-Lok 223 and 224 series retainers offer a minimum clamping force of 1200 N when tightened and offer maximum shock and vibration resistance. An important area of application is also heat dissipation from PCBs. Card-Loks are made of aluminium and can be given various types of surface such as black anodising, chemical nickel plating and chemical film. They are available with profiles of 5.72 x 6.60 mm (series 223) and 5.33 x 6.99 mm (series 224) in various standard lengths from 121.9 to 329.9 mm.

For further information visit www.calmark.com.