type of potentiometer?

i came across a component that i cannot identify. it is in a vibrating table's motor control circuit. it looks like a potentiometer, with three terminals on the side, except it has 4 more terminals in the back! the ac line connects to it, along with the motor and an SCR. you turn it a little, and the device clicks on, and then it is in a variable area, similar to a dimmer switch. i am trying to get the shaker table to work, and i need to know about this knob.

thanks!

Sounds like a pot with a dual-switch to switch the live and neutral. These were very common at one time on some equipment.

**broken link removed**

thats what it sounds like to me too.
A picture would probably confirm it.