Abstract: A tooth brush having a replaceable brush insert complementally receivable in an open loop formed at one end of an elongate handle. The loop is of a symmetrical ovoid configuration. A bead extends fully around the insert and snaps to one side of the loop to secure the insert within the loop. A flange extends around the insert for sealed engagement with the loop upon secure receipt of the insert within the loop.

Abstract: A resonator force transducer assembly includes an elongate base element, a first arm disposed generally in parallel with a front portion of the base element, a first hinge joining the arm near a rear end thereof to the base element at about the middle thereof, an elongate resonator element such as a quartz crystal attached to the front ends of the arm and base element to extend therebetween, a second arm disposed generally in parallel with a rear portion of the base element, and a second hinge joining the second arm to the base element. A third hinge joins the front end of the second arm to the rear end of the first arm to form a type of compound lever arrangement so that when a force is applied to the second arm to urge it either toward or away from the base element, a portion of this force is transmitted via the third hinge to the first arm to urge it either away from or toward the base element to thereby stress the quartz resonator element.