A low blade speed rotary edger useful as an independent tool or as an attachment to a conventional power mower includes a (1) cultivator-rotary blade turning on a vertical shaft and (2) a shearing bar contacting the rotary blade. When used as an attachment for a power mower the rotary blade is connected to the power source of the mower by a belt and pulley system or other suitable drive means. The edger assembly mounted on the power mower is provided with means for retracting the edger to an ino...

A low-liquid level indicator particularly adapted for use in an automotive vehicle which employs an oscillator whose tank coil is shunted by a probe adapted to be immersed in a liquid. When the liquid level is satisfactory, the probe is immersed in the liquid and its impedance will be relatively low thereby reducing the Q of tank circuit to a value where no oscillations will be produced. When the liquid level falls to an unsatisfactory level, the probe will no longer be immersed in the liquid, a...

Low cost, precipitation hardenable, structural steels containing carbon, nickel, molybdenum and columbium, the steels being capable of developing high strength and both ambient and low temperature toughness. Other constituents can be present, notably copper, manganese, silicon, etc.

A steel having excellent notch toughness, for service at low temperatures, which can be used in the normalized or hardened and tempered condition and which contains 0.4-0.13 percent Carbon, 0.15-0.30 percent Silicon, 0.30-0.90 percent Manganese, 8.50-9.50 percent Nickel, 0.020-0.060 percent Aluminum, 0.008-0.020 percent Nitrogen. Balance, Iron and incidental impurities.

High silver content (30 percent, by weight, or greater) gold base alloys are found to have exceptional resistance to silver sulfide tarnish when alloyed with from 0.25 to 10 percent, by weight, indium or preferably indium and cadmium each within the range of 0.25 to 10 percent and such alloys including those containing cadmium alone have been found to exhibit exceptional resistance to carbon film deposits in normal low energy switch applications and frictional polymer formation in sliding low en...

A low-mass truss structure wherein a plurality of angular disposed elongated thin-walled tubular segments are connected to a plurality of joint clusters formed of short tubular members to form a unitary truss structure.

A low frequency astable blocking oscillator composed of a transistor with a irst transformer winding in the collector circuit and a second transformer winding in the base circuit to provide regenerative feedback between the collector and the base. A capacitor is connected to the transistor and is charged by a constant current source to initiate operation of the blocking oscillator when a predetermined voltage is reached. A voltage breakdown device is coupled to the transistor to raise the voltag...

A low liquid level indicator particularly adapted for use in an automotive vehicle which employs the alternating current voltage that appears across the primary winding of the ignition system of the vehicle to energize a probe which is adapted to be immersed in a liquid. A solid state switching network is employed to control the energization of a warning means from a source of direct current electrical energy, for example, the vehicle battery. The probe and the container holding the liquid are c...

An electrical lead-in conductor is effected from ambient to a cryogenic receptacle by means of a vacuum capacitor located in a vacuum surrounding the cryogenic receptacle. One plate of the capacitor leads from ambient to the vacuum area, the other from the vacuum area through the inner wall to the cold area. Heat leak along the conducting element is prevented by the break in the conducting element which the capacitance form of the lead affords.

A memory system is disclosed which includes input means for receiving a binary word to be stored, in which the word comprises a plurality of bits each having either a "one" state or a "zero" state. Counting means are provided for counting the number of bits in the "one" state and for providing an output control signal whenever the number of such bits exceeds one-half of the number of bits in the word. The output signal of the counting means controls an input complementing gate which receives the...