Abstract: The addition of a phospholipid to the halogenated hydrocarbon working fluid of a refrigeration system serves to markedly reduce the corrosion of steel exposed thereto.

Abstract: By sensing the outdoor ambient temperature and the outdoor coil temperature in a heat pump when the outdoor coil is frost-free, a control system determines the split or difference that will later exist between those temperatures (the coil temperature drops as frost accumulates) when sufficient frost has built up on the outdoor coil to necessitate defrosting. When that defrost temperature split, called the Normal Defrost Value or NDV, is exceeded, defrost is initiated and the coil will be defrosted. Since the amount of frost that may have already accumulated on the coil is unknown when the control system is initially powered up (such as when power is restored after an outage), the control system calculates, from the current outdoor ambient temperature, an assumed value for the coil temperature which is likely to exist if the coil were frost-free. The first NDV determined after power up is based on the assumed coil temperature.

Abstract: A continuously variable transmission with synchronous shift includes an input, an output, a fixed-ratio drive mechanism and a variator in driven relationship with the input, a planetary gear assembly having a sun gear, a ring gear, a carrier, and a plurality of planet gears, a first clutch for engaging the variator selectively with the sun and ring gears, a second clutch for engaging the mechanism selectively with the carrier and sun gear and for disengaging the mechanism therefrom, and a third clutch for engaging the ring gear and carrier selectively with the output. This relationship provides the transmission with a plurality of drive ranges and the capability of shifting from any range to any other range at a synchronous shift point established when the variator ratio is equal to the ratio of the mechanism.

Abstract: A single or multiple stage mechanical seal assembly in which one seal ring is resiliently coupled to a rotatable shaft and the other seal ring is resiliently urged toward the first seal ring by axially-arranged identical springs received in spring pockets in a spring retainer, some pockets opening at one radial surface of the retainer and others opening at the other radial surface of the retainer. The outer surfaces of the seal rings are protected against deflection by being encircled by cylindrical members and one seal ring is resiliently coupled to its encircling cylindrical member. A balance sleeve means partly supports the axially movable seal ring and is capable of angular adjustment to compensate for shaft misalignment.

Abstract: An anti-clash and anti-rattle brake for a multiple speed ratio transmission is engageable to apply a frictional braking force to the constantly meshed gears when a shift control device is in a free neutral position. The brake is spring biased toward engagement. It is disengaged by one cam device when the shift control device is moved from the free neutral position in one plane and by another cam device when the shift control device is moved from the free neutral position in another plane.

Abstract: A control valve assembly is disclosed for control of a fluid pressure between a variable fluid pressure source and a fluid operable device. This assembly provides a valve means to open or close flow from the fluid pressure source in response to a change in a significantly lower fluid pressure in a pilot chamber, which fluid pressure is controlled by a proportional solenoid operator requiring small current flow. This small current flow to the solenoid operator is due to the low pressure in the pilot chamber, which when relieved or increased effects a change in the valve meaans to open or close fluid flow to or from the fluid pressure source.

Abstract: A surge detection apparatus for use in a refrigeration system having a centrifugal compressor driven by an electric motor includes a first pressure transducer for sensing a condenser pressure and a second pressure transducer for sensing an evaporator pressure. A first bandpass digital filter responsive to the condenser pressure and the evaporator pressure is provided for generating a first signal representative of the rate of change of the pressure developed across the compressor. A current transformer is used to sense a current in the electric motor driving the compressor. A second bandpass digital filter responsive to the motor current is provided for generating a second signal representative of the rate of change of the RMS current being drawn by the compressor drive motor. A third signal representative of a differential pressure threshold and a fourth signal representative of a first motor current threshold and a second motor current threshold are provided.

Abstract: An improved double wrap brake band for an automatic transmission and the method of making the band wherein the band is lightweight and heat set round at the released open position with the utilization of thinner strap material at higher hardness ranges. The band is formed from a preslotted and preformed strap and a stamped one-piece bracket member secured to the strap. The band subassembly is heat treated and heat set, the interior surface is acid etched and a preslotted friction lining applied to the interior treated surface, the subassembly is sized, and the connecting ties for both the strap and bracket member are removed to provide the final band assembly.

Abstract: A load block for a metal chain belt comprising upper and lower transverse struts, the ends of which are adapted to engage the flanges of the pulleys of a pulley transmission, said struts being joined by recessed end portions, the struts and end portions defining a window for encircling a carrier, the end portions being recessed from the ends of said struts so as not to engage the flanges of the pulleys of a pulley transmission.

Abstract: A chain-belt for drivingly connecting the pulleys of a pulley transmission and constructed of interconnected sets of links which are interleaved with one another with pivot means connecting the sets of links and a load block encircling each set of links with a clip member for retaining the chain parts assembled. The clip is so shaped and orientated to substantially eliminate tilting of each load block with respect to the chain as the belt enters a pulley.

Abstract: Brake holding apparatus for use in a vehicle having a fluid pressure operated braking system including a master cylinder and at least one brake cylinder. The apparatus includes a trapping valve movable to an open position allowing fluid communication between the master and brake cylinders, and to a closed position blocking this fluid communication so as to trap fluid pressure in the brake cylinder. The trapping valve is biased for movement to its open position. Means are provided for moving the trapping valve to its closed position. A bypass valve allows fluid communication from the master cylinder to the brake cylinder, but blocks fluid communication in the opposite direction. The trapping valve is fluid pressure balanced such that fluid pressure trapped in the brake cylinder has no effect on the position of the valve.

Abstract: Apparatus for underfiling curvelinear vanes of cast centrifugal impellers. Such vanes are cast with generally uniform thickness along their length; it is desirable to have the vanes taper in thickness such that the radially outward portions are thinner than the roots; also this provides a desired curve to each side of the blades.

Abstract: Surge protection is provided for a d-c power supply, wherein rectified a-c line voltage is filtered in an LC filter having a shunt-connected filter capacitor, by inserting a limiting resistor in series with the filter capacitor during power-up to reduce the inrush current and the voltage overshoot to acceptable values. Once the power-up period is over and d-c power is fed to a load, the limiting resistor is bypassed.

Abstract: A chain-belt comprising a plurality of interleaved sets of links and load blocks associated therewith. Each link is defined by toes, the toes of each link being defined by parallel inside flanks joined by a crotch. A load block is received between the inside flanks and further a hardened insert is located between the links and the blocks to protect the links and improve the durability of the chain.

Abstract: An accessory drive especially adapted for use with internal combustion engines having a crankshaft is described. The drive comprises a variable pulley transmission having a pair of spaced pulleys drivingly interconnected by a power transmission belt. The pulley transmission having a driver pulley drivingly connected to an engine crankshaft. The driven pulley includes a pair of pulley flanges, one flange is axially movable with respect to the other flange, the driven pulley also comprises a pair of pulley flanges, one of which is axially movable with respect to the other flange. The spacing of the flanges of the drive and driven pulleys determines the drive ratio between the pulleys. Another pulley is connected to the driven pulley, to drive the accessories. A drive pulley spring urges the drive pulley flanges axially toward one another, and a driven pulley spring urges the driven pulley flanges toward one another.

Abstract: Highly reliable and consistent starting is achieved by first initializing the rotor position, namely establishing the rotor in a known starting position. This is accomplished by gating on two pairs of SCRs in sequence and supplying current pulses through the gated SCRs to the stator of the motor to rotate the rotor to a first position and then to a second position, the rotor coming to a complete stop in each of those positions. The rotor aligns itself with the magnetic field created by the stator in each position and any ambiguity in the rotor position is eliminated. Thereafter, the inverter is operated asynchronously in a second mode with predetermined pairs of the inverter SCRs being sequentially gated into conduction at an increasing frequency to current pulse energize the motor to effect step-by-step rotation of the rotor at a faster and faster rate, the motor current being reduced to zero at the termination of each energizing pulse to force commutate the conducting pair of SCRs.

Abstract: The current outdoor ambient temperature and outdoor coil temperature in a heat pump are sensed when the heat pump's outdoor coil is clean and frost-free, and from those current temperatures the split or difference that will later exist between the temperatures, when sufficient frost has built up on the outdoor coil to necessitate defrosting, may be determined. When that defrost temperature split, called the Defrost Value or DV, is reached, defrost is initiated and the frost that has accumulated on the coil is melted. Before defrost occurs, however, changing weather conditions (namely, changing outdoor temperature and/or changing outdoor relative humidity) may effectively invalidate the previously determined defrost temperature split or DV, and a frost condition may be reached at a substantially different temperature split, either greater or smaller than that previously calculated.

Abstract: A torque-limiting clutch includes an input member, an output member, and a friction element relatively movable to an engaged position for frictionally engaging the clutch and to a disengaged position in which the clutch is disengaged. An actuating device develops a clutch-engaging force tending to move the friction element relatively to its engaged position and thereby effect clutch engagement at a predetermined torque load setting. A thermal spring responsive to a small temperature increase develops a clutch-disengaging force tending to move the friction element relatively to its disengaged position and thereby effect rapid clutch disengagement. The thermal spring is formed from a shape memory effect material.

Abstract: The invention teaches the use of a cam-operated valve control means, which cam is moved by an electrical motor in response to an operating signal. Such valve control means finds particular application in an exhaust gas recirculation system or idle speed control for an automobile engine.