Abstract: An electrical system responsive to overheating and/or electric arcing of an electrically conductive member, e.g. a heating member of an aircraft windshield, includes a first switch in a first current path, and a second switch in a second current path. The first current path is from an electrical power supply through the first switch, through an arc sensor to the heating member to the power supply. The second current path is from a temperature sensor monitoring the temperature of the heating member through the second switch to a temperature controller. When the temperature of the heating member is at or above a predetermined value, the temperature controller causes the first switch to open. When there is arcing, the second switch is moved to the open position. The temperature controller senses that the second switch is open and causes the first switch to open.

Abstract: A furnace for shaping glass sheets for aircraft transparencies using the cut-to-size method includes a preheat and cooling furnace defined as a first furnace, and a shaping furnace. A conveyor geared for reciprocating movement moves a bending iron supporting a glass sheet through the first furnace set to a preheat temperature. The glass sheet supported on the bending iron is heated in the shaping furnace by microwave beams from a gyrotron to heat portions of the glass sheet to be shaped to a complex shape. After the sheet is shaped, the conveyor moves the bending iron supporting the shaped glass sheet from the shaping furnace through the first furnace set to a cooling cycle.

Abstract: An electrical system responsive to overheating and/or electric arcing of an electrically conductive member, e.g. a heating member of an aircraft windshield, includes a first switch in a first current path, and a second switch in a second current path. The first current path is from an electrical power supply through the first switch, through an arc sensor to the heating member to the power supply. The second current path is from a temperature sensor monitoring the temperature of the heating member through the second switch to a temperature controller. When the temperature of the heating member is at or above a predetermined value, the temperature controller causes the first switch to open. When there is arcing, the second switch is moved to the open position. The temperature controller senses that the second switch is open and causes the first switch to open.

Abstract: An electrical system responsive to overheating and/or electric arcing of an electrically conductive member, e.g. a heating member of an aircraft windshield, includes a first switch in a first current path, and a second switch in a second current path. The first current path is from an electrical power supply through the first switch, through an arc sensor to the heating member to the power supply. The second current path is from a temperature sensor monitoring the temperature of the heating member through the second switch to a temperature controller. When the temperature of the heating member is at or above a predetermined value, the temperature controller causes the first switch to open. When there is arcing, the second switch is moved to the open position. The temperature controller senses that the second switch is open and causes the first switch to open.

Abstract: A furnace for shaping glass sheets for aircraft transparencies using the cut-to-size method includes a preheat and cooling furnace defined as a first furnace, and a shaping furnace. A conveyor geared for reciprocating movement moves a bending iron supporting a glass sheet through the first furnace set to a preheat temperature. The glass sheet supported on the bending iron is heated in the shaping furnace by microwave beams from a gyrotron to heat portions of the glass sheet to be shaped to a complex shape. After the sheet is shaped, the conveyor moves the bending iron supporting the shaped glass sheet from the shaping furnace through the first furnace set to a cooling cycle.

Abstract: An electrical system responsive to overheating and/or electric arcing of an electrically conductive member, e.g. a heating member of an aircraft windshield, includes a first switch in a first current path, and a second switch in a second current path. The first current path is from an electrical power supply through the first switch, through an arc sensor to the heating member to the power supply. The second current path is from a temperature sensor monitoring the temperature of the heating member through the second switch to a temperature controller. When the temperature of the heating member is at or above a predetermined value, the temperature controller causes the first switch to open. When there is arcing, the second switch is moved to the open position. The temperature controller senses that the second switch is open and causes the first switch to open.

Abstract: A method of tempering a glass sheet heated to a tempering temperature includes cooling the glass sheet at a first heat transfer coefficient at a first quench station and cooling the glass sheet at a second heat transfer coefficient at a second quench station downstream of the first quench station. The second heat transfer coefficient is greater than the first heat transfer coefficient. In a multistage process of the invention, a plurality of quench stations could be used with each downstream quench station having a larger heat transfer coefficient than the previous upstream quench station.

Abstract: A method of tempering a glass sheet heated to a tempering temperature includes cooling the glass sheet at a first heat transfer coefficient at a first quench station and cooling the glass sheet at a second heat transfer coefficient at a second quench station downstream of the first quench station. The second heat transfer coefficient is greater than the first heat transfer coefficient. In a multistage process of the invention, a plurality of quench stations could be used with each downstream quench station having a larger heat transfer coefficient than the previous upstream quench station.

Abstract: A moisture sensor to sense rain on a windshield includes sensor members and leads on the outboard surface of the windshield. The members and leads are uncoated and directly exposed to any moisture accumulation on the sensor. Leads connect the sensor to a controller which includes a signal generator and sensor monitor. The relative spacing between the leads as compared to the spacing between the sensor members is such that the impedance of the sensor when the leads are electrically interconnected by moisture is measurably different from the sensor impedance when said members or said members and leads are electrically interconnected. In response to the latter signal, the windshield wipers are actuated.