Abstract: A sensing element and system for determining the density of fuel housed in the tank of an aircraft, includes sensing element (10). The sensing element has a disc shaped member (20) extending through a wall (16) of the sensor body. The sensor body also encloses a chamber (14) containing dry nitrogen at a pressure of one atmosphere. Electromagnetic driving coils (24) are electrically actuated to cause member 20 to vibrate in its resonant frequency in four quadrants with a node along an axis (22) corresponding to the wall of the sensor and a second node axis (42). Pickup coils (26) in the sensor body sense displacement of the disc shaped member in a location of maximum displacement. Fluid surrounding the sensing element causes mass loading of the exposed portion of the disc shaped member and changes its resonant frequency. The changes in resonant frequency along with values determined through calibration are used by a processor (44) to calculate the density of the fluid.

Abstract: An automatic electronic head demagnetizer is built into a standard cassette housing. The cassette housing is provided with a resiliently mounted pressure pad which forms part of an electrical switch connected to circuitry inside the cassette housing. When the cassette housing is inserted into a conventional cassette tape recorder or playback machine and the "play" button thereof is depressed, the machine head moves into engagement with the pressure pad, pushing the latter into the cassette housing. As a result, the pressure pad, which is electrically conductive, makes electrical contact with another switch component inside the cassette housing, thereby closing an electrical switch in the housing. This activates the control circuit for the demagnetizing inductor. In response to such activation, a demagnetizing field is established and then caused to decay from an initial maximum amplitude towards zero, whereas the frequency of the demagnetizing field is caused to increase from zero.

Abstract: A tape splicer having a base, at least one groove extending longitudinally on said base and being of a predetermined breadth permitting insertion thereinto of a correspondingly wide tape to be spliced. A blade-guiding slot is provided in the groove to allow introduction thereinto of a blade, so that this blade moved along this slot will cut a tape laid along the groove. A pair of tiltable toggles is associated to the base. These toggles are located longitudinally of the groove and at opposite sides of the blade-guiding slot. At least one arm is comprised in each of the toggles and is provided with a tape-clamping means which is arranged so that it reaches, when the toggle is tilted, into the groove; thus, the pair of toggles engages with the tape-clamping means the tape laid into the groove thus securing a clean cut.

Abstract: A degausser has a housing having two housing sections of generally tubular configurations. A support element is accommodated in the interior of the housing, and has a tubular portion and a generally flat portion. A core of an electromagnet is accommodated in the tubular portion of the support element, and a coil of the electromagnet surrounds a part of the tubular portion in the housing. The flat portion is formed with resiliently yieldable projections which engage associated recesses at the housing sections with snap action so as to connect the housing sections to the support element. Electric leads pass through an opening of one of the sections, are received in slots of the flat portion in a labyrinthine manner, and connected to a switch supported on the support element and having an actuating element passing through a slot in the housing to the exterior of the latter. The housing and the support element are of synthetic plastic material.

Abstract: A cassette housing has an open side which faces the head and capstan roller of a tape recording and/or playback unit of the type using magnetic-tape cassettes, when the housing is placed in operative position on the unit in lieu of a tape cassette. One or more first pads are provided for wiping over the periphery of the capstan roller when the latter is rotated and a cam and follower arrangement driven by the tape drive of the unit performs oscillatory motions and wipes over the tape-engaging surface of the magnetic head of the unit.