| 摘要 |
<p>820,592. Detecting icing conditions. NATIONAL RESEARCH COUNCIL. May 15, 1957 [May 24, 1956], No. 15420/57. Class 97(3) [Also in Group XXXIII] A device for detecting icing conditions comprises two orifice type probes mounted to move in a circular path, one being continuously heated to prevent ice formation, a pressure switch being connected between the probes to be operated when the pressure in the unheated probe falls below a predetermined amount. In the form shown the probes 2 and 1, of which the former is continuously heated by a coil 8 energized from a source 19, are carried on an arm 3 rotated about an axis 4. The probes may be as described in Specification 739,527 and are connected by conduits 14, 15 to spaces 27, 27 on either side of a diaphragm 25 with which are associated contacts 12, 13. The orifices in the probe 1 are arranged to provide a greater pressure in the probe than those in the probe 2 so that the contacts 12, 13 are normally open but, if icing occurs on the probe 1, they close to give a warning indication on a lamp 20 and energize a heating coil 7 for the probe 1. Slip rings 16, 17, 18 provide electrical contacts to the rotating parts. A relay may be inserted in series with the lamp 20 to operate the main de-icing equipment e.g. of a helicopter on the rotor of which the probes may be mounted.</p> |
