Force sensor

• US 3,274,828 A
• Filed: 08/27/1963
• Issued: 09/27/1966
• Est. Priority Date: 08/27/1963
• Status: Expired due to Term

• Current Assignee: Charles F. Pulvari
• Original Assignee: Charles F. Pulvari
• Inventors: Pulvari, Charles F.
• Application Number:
  US04/304,852
• Time in Patent Office: 1,127 Days
• US Class Current: 73/862.59
• CPC Class Codes: G01L 1/162 using piezoelectric resonators
• CPC Class Codes: Y10S 73/04 Piezoelectric

Claims

3. A FORCE SENSOR COMPRISING, IN COMBINATIO:

OSCILLATOR MEANS INCLUDING AT LEAST ONE SOLID-STATE ELEMENT IN THE FORM OF A RESONATOR HAVING AN EIGEN FREQUENCY WHICH VARIES WHEN A FORCE IS APPLIED THERETO;

MEANS CONNECTED TO SAID OSCILLATOR MEANS FOR DETECTING A CHANGE IN FREQUENCY WHEN A FORCE IS APPLED TO THE ELEMENT, SAID OSCILLATOR MEANS AND SAID SOLID-STATE ELEMENT BEING ARRANGED SO THAT THE ELEMENT OSCILLATES IN THE SHEAR MODE, AND MEANS FOR TRANSFERRING FORCES BELOW A PREDETERMINED MAXIMUM TO SAID ELEMENT ON A PORTION THEREOF WHERE THE PROPAGATION WAVE VECTOR OF OSCILLATION FOR A GIVEN DIRECTION OF PROPAGATION IS AT AN INSIGNIFICANT VALUE AND IN THE DIRECTION OF THE NEUTRAL PLANE OF SHEAR VIBRATION IN WHICH PLANE PARTICLE DISPLACEMENT REVERSES ITSELF, WHEREBY THE FREQUENCY MAY BE CHANGED BY THE APPLICATION OF FORCE WITHOUT CHANGING THE Q OF THE RESONATOR, SAID FORCE TRANSFERRING MEANS INCLUDING A FORCE APPLYING ELEMENT IN CONTACT WITH SAID ELEMENT, A FORCE RECEIVING ELEMENT MOVABLE RELATIVELY TOWARD AND AWAY FROM SAID FORCE APPLYING ELEMENT, AND A SPRING DISPOSED BETWEEN SAID FORCE ELEMENTS.