Variable-speed controller for use with an electric device

1. A variable-speed controller for use with an electric power tool including:

a variable resistor element having a variable resistor element contact surface;

a membrane including a first membrane contact surface spaced-apart from the variable resistor element contact surface by a spacer element, and, a second membrane contact surface;

a slider configured for slidable movement along the second membrane contact surface wherein responsive to the slider slidably moving along the second membrane contact surface, the first membrane contact surface is able to be urged into contact with the variable resistor element contact surface in a plurality of contact point configurations whereby effective resistance of the variable resistor element is configured to change in response to the first membrane contact surface being urged into contact with the variable resistor element contact surface in each of the plurality of contact point configurations;

an actuator assembly including an actuator operably-connected with the slider whereby the slider is slidably moved relative to the second membrane contact surface responsive to movement of the actuator, and said actuator includes a hand-operable portion via which force is able to be applied to the actuator by a user's hand to move the actuator inwardly of a housing; and

wherein said electric power tool includes at least one of a hand-operable electric drill, electric grinder, electric sander, electric saw, electric rotary driving tool, power tool, and electric gardening tool.

2. The variable-speed controller of claim 1 , further comprising:

a variable-speed trigger assembly.

3. The variable-speed controller of claim 2 , wherein the variable-speed trigger assembly includes the actuator assembly operably connected with the slider whereby the slider is slidably moved relative to the second membrane contact surface responsive to movement of the actuator.

4. The variable-speed controller of claim 1 , wherein the variable resistor element is disposed on a circuit board.

5. The variable-speed controller of claim 1 , wherein the first membrane contact surface is biased into a spaced-apart position relative to the variable resistor element contact surface.

6. The variable-speed controller of claim 1 , wherein the first membrane contact surface and the variable resistor element contact surface include conductive materials.

7. The variable-speed controller of claim 1 , wherein at least one of the first membrane contact surface and the variable resistor element contact surface include printed layers of conductive material.

8. The variable-speed controller of claim 1 , wherein the spacer element is integrally formed with a structure of the membrane.

9. The variable-speed controller of claim 1 , wherein the membrane includes at least one of a polymeric, a co-polymeric, and a polymeric composite material.

10. The variable-speed controller of claim 1 , wherein the variable resistor element contact surface includes a first region comprising a plurality of conductive tracks extending from junctions of a plurality of resistors in series, and, a second region comprising an electrically conductive surface configured for fixed electrical connection with an input pin of an integrated circuit chip of the variable-speed controller.

11. The variable-speed controller of claim 10 , wherein the first and second regions of the variable resistor element contact surface are arranged in at least one of a series and a parallel configuration relative to each other.

12. The variable-speed controller of claim 10 , wherein the slider includes first and second protruding portions configured for urging the first membrane contact surface into contact with the first and second regions, respectively, of the variable resistor element contact surface.

13. The variable-speed controller of claim 12 , wherein the first and second protruding portions are configured for arrangement in at least one of a series and a parallel configuration.