base with one degree of freedom approximately parallel to the front of panel 14 wall 31 of base 21 functions as range limiting structure by impacting interfering structure 32 of operating lid 22 when operating lid moves to the right as shown in fig3 so as to limit the range of motion of the lid to the right wall 33 of base 21 similarly impacts interfering structure 34 of operating lid 22 so as to limit the range of motion of lid 22 to the left handle structure 35 of operating lid 22 is shaped to receive forces from an operator to move lid 22 through a range between position where interfering structure 32 impacts range limiting structure 31 and the position where interfering structure 34 impacts range limiting structure 33 so captured and constrained operating lid has a forward face 36 presented to an operator of appliance 10 and a rearward face 37 facing into cavity 25 the dimensions of operating lid 22 and cavity 25 are arranged so that cavity 25 is covered by lid 22 in all positions within the range of motion of lid 22 switch 15 is mounted on floor 23 of base 21 and is connected to terminals 38.