Abstract: A battery pack 13 (FIG. 2) comprises an elongated cylindrical, metal casing 35, a plurality of cells 41, 43 in casing 35 and three coaxial pack terminals 46, 54, 61. For enhanced convenience, pack terminals 46, 54, 61 are electrically connectable in a cordless device 11 regardless of the angular orientation of the pack 13 about casing axis 33. To reduce cost and increase durability, pack 13 has no welded connections and will permit high current discharge rates. Cells 41, 43 are electrically connected but are mechanically disconnected. A spring 73 engages cell 41 and biases cells 41, 43 tightly together in compression to form good, low resistance electrical contact between cells 41, 43, casing base cap 45 and top 53. To provide a pack with two output voltages, the third pack terminal 61 has a polarity (relative to first pack terminal 46) the same as second pack terminal 54 and is electrically connected to the cell can terminal 43b of forward cell 43, thereby electrically by-passing cell 43.

Abstract: This invention discloses a method and apparatus for rapidly charging a battery by monitoring the voltage of the battery and changing the effective sampling rate of the battery voltage during the charging sequence. More particularly, a first disclosed embodiment of the battery charging system takes voltage readings of the battery as it is being charged at a predetermined rate and stores the voltage values in a first-in, first-out stack in the order in which they are taken. Therefore, a stack of consecutive data samples spaced in time is created. During an interval in the charging sequence where the rate of increase in battery voltage is relatively low, the charging system retrieves voltage values from the stack which are widely separated in time to calculate a slope of the charging profile to determine the status of the charging sequence.

Abstract: The cylindrical plug of a low-voltage, high current capacity connector assembly has an axially positioned sleeve wiping contact and a transversely positioned U-shaped channel member to provide two pairs of planar wiping contact surfaces parallel to the plug axis and substantially perpendicular to the plug housing surface. The socket component, which will accept standard low-voltage, low current car appliance plugs, includes an internally mounted, closed face pin contact and a barrel contact having depending ears positioned to engage the protruding sides of the plug U-shaped channel member. The socket also has an internal boss and housing lip to prevent electrical activation of a standard automotive cigarette lighter plug, and the plug component of the connector assembly has the sleeve contact recessed to prevent contact following insertion into a conventional cigarette lighter socket.

Abstract: A mobile power tool and appliance operating system includes a portable lead-acid battery pack having a high current capacity socket compatible with existing low current plugs used with appliances intended to operate from automotive cigarette lighter sockets. Matable high current capacity plugs are attached to power tools and appliances through retractable cords. The battery pack is receivable in a 120 VAC powered charging base having a self-contained charging circuit including a transformer and a voltage regulator. The high current socket housing prevents inadvertent operation with an automotive cigarette lighter plug, and the high current plug housing prevents electrical contact in a automotive cigarette lighter socket, for safety reasons. In another embodiment, the battery pack is provided with two sockets for delivering different power outputs at each respective socket. Recharging of the battery pack can also be accomplished via connection made to one of the sockets.

Abstract: A method for determining the volume of compressible gas in a system including incompressible substances in a zero-gravity environment consisting of measuring the change in pressure (.DELTA.P) for a known volume change rate (.DELTA.V/.DELTA.t) in the polytropic region between isothermal and adiabatic conditions. The measurements are utilized in an idealized formula for determining the change in isothermal pressure (.DELTA.P.sub.iso) for the gas. From the isothermal pressure change (.DELTA.P.sub.iso) the gas volume is obtained. The method is also applicable to determination of gas volume by utilizing work (W) in the compression process. In a passive system, the relationship of specific densities can be obtained.

Abstract: A pulsating D.C. voltage is developed by a rectifier 86 and is filtered by a capacitor 100 to facilitate application of a relatively smooth, enhanced D.C. voltage to a motor 106.The charged voltage of capacitor 100 is applied across a series circuit which includes a rheostat 118, a resistor 126 and motor 106. When the CEMF of motor 106 drops as a result of a decrease in motor speed, a disc 122 is biased through the voltage appearing across rheostat 118 and resistor 126 to cause an SCR 116 to fire. When SCR 116 fires, the voltage of capacitor 100 supplies a boost of power to motor 106 to overcome the decrease in motor speed.A circuit 212 prevents an overspeed of motor 106 from occurring while braking circuits 264, 266 and 268 provide for a dynamic braking effect when the motor is a universal motor.

Abstract: A non-isolated battery charger for direct connection to an AC source provides rectified DC current to the battery being charged. A thermostat in a heat conducting relationship with the battery senses battery temperature and discontinues the charging current when the temperature of the battery rises after attaining full charge. In one form of the invention, a trickle charge path is provided to the battery to maintain its charge state after the full charge has been attained. The trickle charge path is provided by an impedance shunting the thermostat and is operative as a current path when the thermostat is in its open condition. The trickle charge path can be a resistor where the thermostat is in the DC part of the charger circuit or a capacitor where the thermostat is in the AC part of the charge circuit.

Abstract: A dual-mode system for operating electrically powered devices, such as hand-held power tools and appliances, includes a cordless battery pack that supplies the power and current demands of the device in a cordless mode or a corded voltage converter that supplies the necessary power and current demands in a physical envelope commensurate in size and interchangeable with that of the battery pack. The corded voltage converter is provided with a high efficiency power supply that allows the converter to generate the power and current required by the driven device and accommodate widely varying loads consequent to normal operation of the device and do so in a physical envelope that is commensurate in size with and interchangeable with the cordless battery pack. The corded voltage converter includes a power conditioner that conditions input source current, such as 120 or 240 volts AC or DC, to provide a relatively high DC voltage that is chopped at a comparatively high frequency, e.g., 25 KHz, by switching devices.

Abstract: A corded/cordless dual-mode power-operated device, such as a household vacuum cleaner, can be operated in corded mode from a conventional power source and in a cordless mode using energy provided from an internal rechargable battery and which includes an internal battery charger for recharging the battery when the device is in its corded mode. The internal charger includes a voltage converter that converts input source current to a relatively high DC current that is chopped at a comparatively high frequency, e.g., 25 KHz, by switching devices. The high-frequency, high voltage current is presented to a step-down transformer with the stepped-down output rectified to provide a low-voltage DC suitable for recharging the internal battery when the device is in its corded mode. The voltage converter advantageously provides for the high efficiency conversion of the input energy to meet the charging current demands of the internal battery in a physically compact device.

Abstract: A permanent magnet motor for use in such electrically-powered devices as appliances, power tools, and the like includes a longitudinally-split cylindrical ferromagnetic wrapper having an inner diameter normally less in its free state than the outer cross-sectional dimension of a permanent magnet array. During assembly of the motor, the split wrapper is expanded to fit around the magnet array, and then is allowed to contract to urge the magnet array radially inwardly against cooperating surfaces formed on each of two end caps. This maintains a predetermined orientation or alignment of the magnet array relative to the armature, including, for example, a predetermined air gap between the magnet array and the armature. Accordingly, the conventional requirement for such additional retention mechanisms as spring clips, adhesives, fasteners, and the like, is eliminated.

Abstract: A permanent magnet motor for use in such electrically-powered devices as appliances, power tools, and the like includes a longitudinally-split cylindrical ferromagnetic wrapper having an inner diameter normally less in its free state than the outer cross-sectional dimension of a permanent magnet array. During assembly of the motor, the split wrapper is expanded to fit around the magnet array, and then is allowed to contract, to urge the magnet array radially inwardly against cooperating surfaces formed on each of two end caps. This maintains a predetermined orientation or alignment of the magnet array relative to the armature, including, for example, a predetermined air gap between the magnet array and the armature. Accordingly, the conventional requirement for such additional retention mechanisms as spring clips, adhesives, fasteners, and the like, is eliminated.

Abstract: A carrier for holding a plurality of articles which includes a shell formed of relatively thin printable sheet material having a molded plastic frame bonded to the underside thereof.

Abstract: An inner pad for holding slices of bacon within an outer package and having a window opening and protrusions extending from the underside thereof adjacent the opening.

Abstract: A method of fast charging batteries by means of precise analysis of the profile of the variation with time of a characteristic of the battery which is indicative of the variation in stored chemical energy as the battery is charged. The method specifically comprises analyzing the profile for the occurrence of a particular series of events preferably including one or more inflection points which precisely identify the point in time at which the application of a fast charge rate should be discontinued. Additional methods of analysis provide for termination or control of the charging current upon the occurrence of other events such as limiting values on time, voltage or voltage slope or a negative change in the level of stored energy.Apparatus for performing these methods comprises a suitable power supply and a microcomputer for analyzing the profile and controlling the power supply.

Abstract: A method and apparatus are presented for charging batteries at a high rate without damaging or reducing the life of the battery. The method comprises monitoring the level of energy stored in the battery, preferably by monitoring a particular battery characteristic. The variation of the characteristic with time is analyzed, preferably by measuring successive values of the characteristic, computing the slope and comparing successive slope values so as to identify inflection points and other significant events in the variation of the characteristic.Apparatus for performing these methods and for controlling the supply of energy is disclosed which comprises suitable power supply and a programed microcomputer for measuring successive values of the characteristic, performing the required computations, and controlling the supply of energy applied to the battery by the power supply.

Abstract: A tubular paperboard carton has a side wall, a bottom wall, and gussets foldably attached to said walls. The side wall is formed from a pair of panels at least one of which has a recess on its edge. The recess is interposed between a gusset and an edge of the other of said side wall forming panels when the carton is erected. A spot of adhesive is applied at the juncture of the gussets.

Abstract: A reinforced corner construction for a hollow wall, tray-type paperboard carton having, opposed pairs of hollow side walls, corner flaps extending from the ends of each side wall to the adjacent side wall, and reinforcing panels on the corner flaps.