Mounting arrangement for piezoelectric sensor device

1. A piezoelectric touch switch mounting apparatus ( 1 ), comprising:

an overlay ( 2 ) having a top surface and a bottom surface, said overlay configured for being disposed over a piezoelectric touch switch and further configured to bend in response to a pressure exerted on the top surface of the overlay ( 2 );

at least one piezoelectric touch switch ( 18 , 27 , 90 ), each piezoelectric touch switch ( 18 , 27 , 90 ) comprising at least one piezoelectric sensor ( 13 ) and disposed below the bottom surface of the overlay ( 2 ), the at least one piezoelectric sensor configured so that the piezoelectric sensor ( 13 ) bends in response to a pressure exerted on the overlay ( 2 ) causing the overlay ( 2 ) to bend;

a piezoelectric touch switch ( 18 , 27 , 90 ) mount comprising;

a mounting bracket ( 4 ) defining at least one opening ( 10 ), the mounting bracket ( 4 ) attached proximate a first end to the bottom surface of the overlay ( 2 ) with an adhesive attachment element ( 3 ) wherein the adhesive attachment element ( 3 ) adheres to the bottom surface of the overlay ( 2 ) in such a manner that an opposite upper surface of the overlay ( 2 ) remains intact and not penetrated by the adhesive attachment element, the at least one piezoelectric touch switch ( 13 ) located in the area of the at least one opening ( 10 );

at least one backer piece ( 5 ), disposed proximate a second end of the mounting bracket ( 4 ), said second end opposite said first end of the mounting bracket ( 4 );

at least one squeezer ( 7 ) disposed in the at least one opening ( 10 ) between the at least one backer piece ( 5 ) and a bottom surface of the at least one piezoelectric touch switch ( 13 ); and

one or more continuously adjustable compression adjusters ( 6 ) coupled to said mounting bracket ( 4 ) and configured to operate on the backer piece ( 5 ) to compress the piezoelectric touch switch ( 18 , 27 , 90 ) and the at least one squeezer ( 7 ) between the overlay ( 2 ) and the backer piece ( 5 ) without penetrating the top surface of the overlay ( 2 ).

2. The piezoelectric touch switch mounting apparatus ( 1 ) according to claim 1 , further comprising at least one sensitivity booster ( 19 ) disposed in the opening ( 10 ) between the surface ( 2 ) and the at least one piezoelectric sensor ( 13 ).

3. The piezoelectric touch switch mounting apparatus ( 1 ) according to claim 1 , wherein the at least one piezoelectric sensor ( 13 ) comprises one or more sheets ( 13 a ) of piezoelectric material placed on substrate ( 14 ) that is supported by edges of an opening ( 28 ), enabling the bending of the piezoelectric sensor ( 13 ).

4. The piezoelectric touch switch mounting apparatus ( 1 ) according to claim 1 , wherein the at least one squeezer ( 7 ) has at least one recess ( 30 ), configured to facilitate the bending of the piezoelectric sensor ( 13 ).

5. The piezoelectric touch switch mounting apparatus ( 1 ) according to claim 4 , wherein the at least one opening ( 30 ) is located below the piezoelectric sensor ( 13 ).

6. The piezoelectric touch switch mounting apparatus ( 1 ) according to claim 4 , wherein the at least one opening ( 30 ) is located laterally displaced from the piezoelectric sensor ( 13 ).

7. The piezoelectric touch switch mounting apparatus ( 1 ) according to claim 1 , wherein: the at least one squeezer ( 7 ) includes a thermal expansion that is greater than the thermal expansion of the mounting bracket ( 4 ) and the backer piece ( 5 ).

8. The piezoelectric touch switch mounting apparatus ( 1 ) according to claim 1 , wherein: the mounting bracket ( 4 ) is connected to the surface ( 2 ) by adhesive ( 3 ), and wherein one or more of a sensitivity booster ( 19 ) and the at least one squeezer ( 7 ) are configured to compensate for stiffness or elasticity of the overlay ( 2 ), for geometrical hysteresis, such as due to heat cycling, or for geometrical inaccuracies, such as due to manufacturing tolerances, in such a manner that a reference force, pressure or strain exerted to the overlay ( 2 ) generates an output of the at least piezoelectric sensor ( 13 ) that is within a pre-defined range, by setting the continuously adjustable compression adjuster ( 6 ) to a defined position.

9. The piezoelectric touch switch mounting apparatus ( 1 ) according to claim 1 , wherein the overlay ( 2 ) is a uniform overlay.

10. The piezoelectric touch switch mounting apparatus ( 1 ) according to claim 1 , further comprising signalling means configured to indicate a valid piezoelectric touch switch interaction.

11. The piezoelectric touch switch mounting apparatus ( 1 ) according to claim 10 , wherein said signalling means comprises means to increase an operating voltage across any one of the at least one piezoelectric sensor ( 13 ).

12. The piezoelectric touch switch mounting apparatus ( 1 ) according to claim 11 , wherein the signalling means is configured to increase the operating voltage across the piezoelectric sensor ( 13 ) that detected the piezoelectric touch switch interaction, preferably by using a boost converter that may be controlled by a microcontroller ( 40 ) adapted to read signals from any one or all of the piezoelectric sensor devices ( 18 , 27 , 90 ).

13. The piezoelectric touch switch mounting apparatus ( 1 ) according to claim 10 , wherein the signalling means comprises one of a buzzer ( 65 ) or a light source.