Abstract: An overcurrent protection device for a load 24 having a housing 100 with fixed contacts 108, 110, movable contacts 118, 120 and terminals 102, 104 for electrical connection to the load. A first snap acting bimetallic 116 member in the device is responsive to heat from overcurrent conditions at a first snap temperature and a second snap acting bimetallic member 12 is responsive to heat at a second higher temperature in the event of failure in operation of the first bimetallic member. The first bimetallic member 116 controls the movement of the movable contacts 118, 120 to cause engagement and nonengagement with the stationary contacts 108, 110, and the second snap acting bimetallic member 12 controls electrical connection between the fixed contact 102 and terminal 108, and is not resetable upon breaking the electrical connection.

Abstract: A pressure responsive sensor 10 for use with a vehicular air bag inflation system is shown having an electric switch 24 actuatable by a snap acting disc 40 when the gas pressure in the gas storage bottle 48 decreases to a selected low level. The snap acting disc 40 is exposed on one side to the gas mixture P1 in bottle 48 and the opposite side to a reference gas mixture P2 in a reference chamber 34. The gas mixture P2 in the reference chamber is filled to a lower pressure level than hat in the bottle in order to provide switch actuation at the desired level and comprises a mixture of gases to enhance leakage testing and tracking of the pressure vs. temperature characteristic curve of the bottle gas mixture.

Abstract: A phase monitor and protection circuit is shown in which an impedance network (21, 23, 25) in a respective branch (20, 22, 24) connected to a neutral (26) is coupled to each phase of a three phase power supply (L1, L2, L3) to create a known voltage profile across the respective networks. A relay network (36) is coupled to one branch (20) and a control network (30) is coupled to a second branch (24) to monitor the voltage levels and deenergize the relay (R1) upon the occurrence of the reversal of any two phases or the loss of a phase. The control circuit can also be used to detect low voltage conditions and in a second embodiment provides a time delay network (44) to avoid nuisance tripping due to transient low voltage or brown out condition.

Abstract: The invention relates to a device for measuring pressures or forces, comprising a pressure or force sensor in the form of a piezoelectric or piezoresistive pressure or force transducer having at least one electric cable connected thereto, and an incompressible elastomer mass which transmits the pressure or force to be measured to the transducer.

Abstract: A pressure sensor for providing an electrical signal corresponding to pressure in a cylinder of an automotive engine has a rigid load-spreading element rigidly secured to a first surface of a ceramic piezoelectric body by a rigid bonding material precisely conformed to the first surface to be in substantially uniform load-transferring relation to all parts of the first body surface, has a rigid support member rigidly secured to a parallel, opposite surface of the ceramic piezoelectric body by a rigid bonding material precisely conformed to the opposite surface to be in substantially uniform load-transferring relation to all parts of the opposite body surface to form a piezoelectric unit, and has a peripheral part of the rigid support member precisely mounted with an interference fit in a bore in a metal component of a mounting structure so that the body of piezoelectric material and the load-spreading element extend in cantilever relation at a precisely determined location to be engaged by force applied throu

Abstract: A method of forming an enclosure for an electric circuit and the enclosure wherein there is provided a boat of material having a bottom and side wall, placing a material having a substantially higher thermal conductivity and a lower melting point than that of the boat in the boat bottom, heating the material to a temperature above the melting point thereof and below the melting point of the boat to cause the material to flow along the bottom to form a layer of the material thereon and join the layer to the bottom and side wall and removing a sufficient amount of the bottom of said boat to expose the layer. In accordance with a second embodiment, a depression is formed in the bottom, and when the material flows along the bottom, it fills the depression and becomes joined to the bottom. Plural such depressions can be provided. The exterior portion of the bottom is removed to expose the material if the depressions do not extend completely through the bottom.

Abstract: An accelerometer is shown with improved drop resistance for regulating automotive safety air-bag systems and the like. The device comprises a member of silicon semiconducting material having a central seismic mass mounted on a surrounding support by intervening beams, a pair of beams extending from each of four sides of the mass to the support and the mass being otherwise free of connection to the support to permit movement of the mass along an axis perpendicular to the plane of the support in highly sensitive response to acceleration forces along that axis. Each beam extends from a location near an end of one side of the mass so that the two beams extending from each side of the mass are widely spaced relative to each other to oppose rotational or twisting movement of the mass in response to off-axis acceleration forces to prevent damage to the beams during dropping of the accelerometer to the extent possible consistent with providing the desired sensitivity of response.