Failures detected by a tester are collated with defects detected by a defect checking device (Step S6). The collation is performed by retrieving defects coincident with each failure within a tolerance R0. Based on a mean value of displacements between the failures and the defects which are coincident with each other, coordinate values of the defects are corrected (Step S10). The coordinate values are corrected only when a collating ratio S that is a ratio of failures with which defects are coinc...

The invention relates to a pressure imbalance detector for use in a vehicle hydraulic brake system having two separate sub-circuits, wherein an electrical indicator device is activated if one of the brake sub-circuits fails. The indicator device includes an electrical switch actuated by a movable sleeve located between two pistons, each of which being responsive to the fluid pressure existing in one sub-circuits. The pistons have an annular shape for receiving fixed rods on which bear the ends o...

A logic equivalence gate compares signals supplied to and received from an electronic switching circuit to produce an output signal when the switching circuit fails to perform a specified switching operation. A pulse width discriminator rejects noise normally present in the output signal caused by the inherent delay of the switching circuit in normal operation. The noise free output of the pulse width discriminator is applied to a flip flop to provide a stored indication of failure of the switch...

A brake failure indicator comprises a piston having opposite ends exposed to the pressure in two hydraulic braking circuits, a ball located in a groove around the piston, a switch operated by radial movement of the ball caused by limited axial movement of the piston, and a self-energising indicating circuit operated by the switch.

A thermocouple-failure warning circuit for use with a thermocouple-controlled circuit that includes an operational amplifier having first and second inputs. A reference voltage is established at the first amplifier input and the thermocouple is connected between the first input and the second input so that a current can flow through the thermocouple to a point which is at ground potential. An electrically actuable warning device is coupled through a transistor circuit to one lead of the thermoco...

A brake failure warning device including an electrically conductive leaf spring which is spaced apart from an arcuate portion of the brake shoe and has one end biased towards the shoe. Connected to the one end of the leaf spring is a conductive plate, also spaced apart from the shoe, and a pin extending from the plate through the shoe a predetermined distance into the brake lining. The other end of the leaf spring is connected to, but electrically insulated from, the shoe via a non-conductive bl...

An electrical relay has an energizing winding and electrical relay contacts controlled in position by the winding. An energizing circuit electrically connects the energizing winding of the relay to one of the conductors of the power system at one of the conductors of an electrical appliance and to the other conductor of the appliance for maintaining the winding energized during operation of the power system and the appliance. A warning circuit electrically connects a source of electrical energy,...

A flame failure device has a hollow, tubular, heat-resistant, temperature sensitive member to be directly heated by a flame and so arranged that the member will expand or contract along a generally rectilinear axis as it is heated or cooled. The temperature-sensitive member is connected to a mount in a manner which permits or permitted at least initial adjustment of the relative position of the mount and temperature-sensitive element along the generally rectilinear axis and has an abutment which...

An indicator for recording the load at which a fatigue specimen breaks during the last cycle of a fatigue test. A load cell is attached to the specimen which is alternately subjected to tension and compression loads. The output of the load cell which is proportional to the load on the specimen is applied to the input of a peak detector. Each time that the specimen is subjected to a compression load, means are provided for appyling a positive voltage to the reset of the peak detector to reset it....

A mechanism mounted adjacent one end of a roller bearing carries a probe biased against ends of the rollers, the probe having a shoe wide enough to span at least two rollers. A spring biased hammer is latched in a cocked condition by a latch device which is controlled by the probe. A bell or sounder rotates in a path near the hammer. When the cage of the bearing fails prior to bearing failure, the rollers bunch up forming a gap which allows the probe to drop into the gap to unlatch the hammer wh...