Duraswitch's PushGate push-button electronic switch is truly unique in that it incorporates all the best features of both discrete and
membrane technology, thus giving the customer the best of both worlds at a competitive price. The patented magnetic armature design provides crisp, tease-proof and reliable tactile feedback as each
switch is actuated without the "spongy" feel of typical tactile membrane switches.
The advantages of this next generation technology go far beyond merely providing a second-to-none
feel. By design, each switch is shielded against EMI/RFI interference as well as static discharge. Actuation force is uniform over the face of each switch while still providing the travel so coveted by
the user to give him a feeling that he has "done something" when he actuates a switch. All of this is provided while still maintaining the long life and sealed washable surface of a
typical membrane switch.
 The basic PushGate is shown in figure #1. It is composed of a membrane, a steel plate, a magnetic sheet, an armature, a spacer and a substrate with
either plated etched copper or silver contacts on its upper surface. The armature is held in place against the magnetic sheet by the magnetic field. As shown in the figure, the armature has a
pivot point mechanically formed into it. An actuating button is also mechanically formed into the armature. This actuating button protrudes up through the magnetic
sheet material and is exposed on the top side of the switch. An overlay or label may or may not be placed over the top side of the switch to provide a seal against dust,
dirt and spilled liquids as well as providing a surface for graphics to be printed. It is recommended that the overlay be embossed to provide space for the actuating button and also to
provide material movement. During actuation, pre-travel is achieved when the overlay is first deformed to come into contact with the actuating button. As the overay is further deformed, the armature
abruptly breaks away from the magnetic sheet material, thus providing a very crisp tactile sensation. The switch is actuated when the armature contacts the second pad on the top surface
of the substrate. Improved tactile feel can be achieved by placing a ferro-magnetic material on the top surface of the magnetic sheet material. This material has the effect of directing the
magnetic field downward toward the armature. The material further enhances the tactile sensation by providing rigidity to the magnetic sheet material. One example of this material
would be thin, soft steel sheet.
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