Patent ID: 11892326
Assignee: ARONIX LLC
Field: Medical technology (Instruments)
Classification: CPC A  G | IPC A  G

Claim 12:
13. An improved tocodynamometer transducer comprising:
more than one of a metal fastener;
more than one of a threaded metal insert;
a bottom enclosure having a bottom internal side, a skin-contacting side, and a diaphragm opening therethrough;
a top enclosure having a top exterior side and a top internal side, more than one of a standoff is integrally formed on the top internal surface and the bottom internal surface, each of the standoff on the top internal surface is conical in shape and wider at the attachment point on the top internal surface, the threaded metal insert is fitted into each of the standoff on the bottom internal surface;
a diaphragm is circular in shape, the diaphragm comprises a flexible relief channel integrally formed in the diaphragm proximate to perimeter of the diaphragm defining a diaphragm deflection area, the diaphragm is secured within the diaphragm opening;
a plunger comprises a shaft having a shaft hole along length of the shaft that is threaded, and a deflection surface having a plunger top side and a plunger bottom side, the plunger top side and the plunger bottom side are flat and absent raised embossed features, the deflection surface is circular in shape and sized to substantially fit within the deflection area, the shaft is circular in shape and uniform in diameter along length of the shaft, the shaft is integrally attached to center of the plunger top side forming a 90-degree angle between the shaft and the deflection surface around circumference of the shaft, the shaft further comprises a thread pattern embossed around outer circumference;
a ferrite core is threaded around outer circumference and solid in composition, the ferrite core is screwed into the shaft hole;
a transformer housing is circular in shape, the transformer housing comprises a housing bottom having a housing hole centrally located therethrough, an outer circumference surface, and a housing interior region, the housing bottom having a diaphragm facing outer surface that is flat and absent raised embossed features maximizing deflection distance between the plunger top side and the diaphragm facing outer surface, more than one mounting tab having a transformer housing mounting hole therethrough, the mounting tab is integrally formed along the outer circumference surface, more than one of a magnetic shield standoff and more than one of a spring standoff are integrally formed in the housing interior region, the threaded metal insert is fitted into each of the magnetic shield standoff and the spring standoff;
a linear variable differential transformer having a circular air core, a top wire winding edge and a bottom wire winding edge that is defined by location and length of a wire winding around the circular air core, the plunger transitions between a maximum deflection and a minimum deflection, during the maximum deflection the ferrite core is positioned below the top wire winding edge and during a minimum deflection the ferrite core is positioned above the bottom wire winding edge, wherein the ferrite core remains within length of the wire winding of the linear variable differential transformer generating a linear voltage output across the plunger range of travel;
a magnetic shield enclosure comprises a top shield having a top shield hole that is centrally located and at least one shield mounting hole, and a bottom shield having a shield interior region and a bottom shield hole that is centrally located, the bottom shield hole is aligned with the top shield hole, the linear variable differential transformer is fitted into the shield interior region and non-magnetic machine screw type of the metal fastener passes through the shield mounting hole and into the threaded metal insert that are fitted into the transformer mounting standoff securing the linear variable differential transformer to the transformer housing, the shaft of the plunger is placed through the housing hole, the bottom shield hole, the circular air core, and the top shield hole, the plunger bottom side is placed in contact with the diaphragm deflection area and machine screw type of the metal fastener is placed through the transformer housing mounting hole and into the threaded metal insert fitted into the transformer housing standoff securing the transformer housing and precisely aligning co-planar the deflection surface, the diaphragm facing outer surface, and the diaphragm deflection area;
a flat spring is formed from single contiguous piece of metal, the flat spring comprises an outer ring, an inner ring, and four of a spring rib, the outer ring having more than one of a spring mounting hole, each of the spring rib is symmetrical, curvilinear in shape, identical in path length, separated by an air gap, and equally spaced between the outer ring, the inner ring, and the spring rib that are adjacent, each of the spring rib is connected, in integrally formed manner, at a first end to the outer ring and a second end to the inner ring, wherein spring constant of the flat spring is predetermined by thickness of the flat spring and identical along two or more axes with respect to the inner ring;
a spring washer comprises a threaded raised inner collar that is sized, fitted through the inner ring, and adhered to the flat spring, surface of the spring washer is flat and absent raised embossed features, the shaft screws into and protrudes from the spring washer, machine screw type of the metal fastener is placed through the spring mounting hole and into the threaded metal insert that is in the spring standoff securing the flat spring and precisely aligning the spring washer co-planar with the deflection surface, the diaphragm facing outer surface, and the diaphragm deflection area, the top enclosure and the bottom enclosure are joined and secured together.