Abstract: Apparatus for reconditioning water-based, synthetic and semi-synthetic coolants. The apparatus comprises a stainless steel mesh filter for removing larger particulate, a coalescer to agglomerate oil droplets and enable a disk skimmer to remove and transfer the separated oil to an oil reservoir, and an inverted, coolant-driven centrifugal separator to separate the smaller particulate down to one micron or smaller in size. Part of the cleaned coolant is combined with the partially cleaned coolant to enable multiple passes of the coolant to assure removal of the particulate. The coolant is pumped using two double-diaphragm air pumps for best control of flow rate and pressure and for good suction for the size of the pump. A biocide may optionally be added to stabilize the coolant. In addition to being able to separate particulate, the separator has sufficient thrust to partially separate the constituents of the coolant as well.

Abstract: A portable transceiver has a battery saving feature which includes a timer, circuit which automatically cuts off the power supply to the receiver and transmitter for relatively long intervals and periodically turns on the power supply for relatively short intevals to check for transmission or receiver signals. If such signals are detected, the power supply continues to supply powers to the receiver and transmitter for the duration of the signals and for a short period thereafter. The transceiver also includes a batter voltage detection circuit which will cut off the battery power supply if the battery has discharge to a predetermined level , and which can be overridden in any emergency. The power supply is conveniently controlled by a pass device which must receive "operate" signals from both the timer circuit and the battery voltage detection circuit.

Abstract: A hand-held radio has thumbwheels for channel selection extending outwardly of an aperture in the top panel of the case, and a cover of resiliently deflectable transparent synthetic resin is disposed thereover and effects a seal thereabout to substantially prevent rain and spray from entering the interior through the apertures about the thumbwheels. The cover has a pedestal portion with a top wall spaced above the thumbwheels and with an inclined sidewall which is spaced laterally outwardly from the thumbwheels, and a peripheral flange extends about the base of the sidewall. A clamping plate has an aperture through which the pedestal portion extends, and it overlies the flange of the cover. Fasteners seated in the clamping plate tightly clamp the flange of the cover against the top panel of the case to effect a seal. The user is able to deflect the cover top wall downwardly and then laterally to rotate the thumbwheels.