Abstract: This invention is a method of making negative battery plates in a continuous process, in which a skeletal grid is cast continuously to have the structure of a number of plate grids side by side and longitudinally integrally connected together in the casting. After casting the skeletal grid is pasted, tissues are applied on either side, and then the grid is cut by slitting and transversely to separate the composite grid into separate pasted battery plates.

Abstract: A battery has a container sealed by a lid in which two shallow recesses are formed. Within each recess is a terminal which does not project out of the recess and which has a tapped hole afforded by a hard metal insert. Two elongate terminal connectors are provided with a hole at one end and a current take-off portion at the other end. The battery is sold with the recesses closed by two flush cover plates and two terminal connectors of desired type. The cover plates are removed and the terminal connectors connected to the terminals by means of screws. A part of each terminal connector is accommodated in the recesses thus restraining the terminal connectors from rotation.

Abstract: A method of manufacturing a recombinant lead acid battery includes placing two or more cell packs in a battery container and then loading the container into a frame mounted on a rotary capstan. The container is transferred to a moulding station and the plate straps and intercell connectors are moulded around the plate lugs. The container is then transferred to a coating station and the intercell connectors are dipped while still hot into a fluidized bed of epoxy resin particles. The particles adhere to the intercell connectors and are cured by their heat thereby forming an impervious layer around them. This layer acts as an electrolyte creepage barrier and prevents the surface of the intercell connectors acting as an electrolyte path for intercell ionic leakage.

Abstract: A variable reluctance electric motor system includes a variable reluctance motor having a main winding for each phase and a power converter circuit including a main thyristor in series with each main winding connected across a direct voltage source from which the main windings are supplied sequentially with uni-directional current pulses, characterized by a commutating thyristor (16) for starving the main thyristor (12) of the current flowing through one main winding (11) while charging a capacitor unit (51,52) in one sense, and a commutating thyristor (26) for starving the main thyristor (22) of the next phase winding (21) of the current flowing through the next main winding (21) while charging the capacitor unit in the other sense.

Abstract: This invention is a pivot mounting for a lamp (12) comprising a pair of journal bearings (30) and two parallel semi-circular springs (14, 16) urging the bearings towards one another, the bearings having gripping surfaces (56) for the mirror. The springs (14, 16) allow the bearings to be separated to admit the mirror which is then held by the resilience of the springs.

Abstract: Recombination lead acid electric storage battery of sealed or recombinant type in which the gas evolved during operation or charging is induced to recombine within the battery at the battery electrodes.

Abstract: A variable reluctance electric motor system including a variable reluctance motor having main windings (A,B,C,D) and auxiliary windings closely coupled to the main windings, a main storage battery for driving the motor terminals (10,11) (that will be referred to as DC supply terminals), and a power converter circuit (FIG. 2) for charging the battery from the DC supply, in which the motor is included in the power converter circuit to function as an isolating transformer to isolate the battery from the supply when on charge.

Abstract: A method of making an extruded strip less than 1.27 mms thick of lead antimony alloy containing 1 to 2% by weight antimony, the strip having an aspect ratio in excess of 10:1 comprises supplying the alloy at a temperature of 200.degree. C. to 280.degree. C. to an extrusion die and forcing it therethrough so that its temperature as it emerges from the die is in excess of 200.degree. C. and quenching the strip as it emerges from the die whereby its tensile strength within 6 hours of emerging from the die is about 35 Newtons/square mm.sup.2. This strip is suitable for conversion to a battery electrode.

Abstract: A high frequency converter of push-pull form comprises a center tapped D.C. input supply 16, 17, 18, two solid state switching devices (20, 21) connected in series across the D.C. input terminals, a load circuit including a supersonic frequency transformer 30 and an output rectifier 35, and an oscillatory circuit including at least one capacitor 40 and a parallel inductor 34 connected in parallel with the primary winding 37 of the transformer between the center tapping 19 of the supply and the junction 25 of the switching devices. The switching devices are synchronized to the oscillation of the oscillatory circuit to allow the circuit to oscillate freely for part of a cycle to transfer energy from the inductor 34 to the capacitor 40 to charge the latter to a certain condition in which the voltage across the parallel inductor is substantial and that across the switching device is negligible and only then connect the parallel inductor across the D.C.

Abstract: A battery includes a plurality of frames of plastics material, each frame comprising a perimeter member and one or more division elements together defining two or more active material support spaces. The frames are arranged in a stack and the perimeter member and division elements of each frame are connected to those of adjacent frames. Each support space receives an electrode, and every alternate division element has on one side two connector recesses extending over a minor proportion of its length, connector recesses in adjacent frames being in division elements that are offset from one another. The spaces on each side of each division element receive electrodes which are connected together by connectors which are received in the connector recesses. Preferably that portion of each division element which overlies a connector recess in the adjacent frame has an elongate recess in it, the connector recess and elongate recess containing a sealing material.

Abstract: A vent plug includes a thermophastic tubular body for insertion in an aperture in the lid of a battery. The vent plug has at its upper end an integral lid with a gas venting aperture formed therein. A removable insert is secured within the tubular body and defines a tortuous gas venting path. The insert and the body are constructed to define a space with which the gas venting aperture and the gas venting path communicate, the space accommodating a porous flame retarding body.

Abstract: A device for filling or topping-up batteries, including a trolley, a reservoir for acid or distilled water, and conduits for connection to the inlet and the outlet ends of a series of filler devices, one on each battery cell. At the end of the series a conduit is connected to a sump on a trolley. A pump draws liquid by siphon from the reservoir through the filling devices to the sump. A level responsive switch in the sump is used for terminating the filling operation which can be performed automatically by connecting the conduits and switching on the equipment. A timer and an air valve ensure that all the liquid is sucked out of the line after the cells have been filled before the pump is switched off. Automatic connections connect the inlet and outlet to exhaust through explosion minimizing vents once the conduits have been disconnected.

Abstract: An electric battery has one or more cells in a single container and an outer lid. The container and the outer lid have respective divergent engagement surfaces comprising the lower surface of a ledge on the container and the upper surface of a slot in the lid respectively. Fastening means comprising a channel section clip with divergent limbs is placed in contact with the engagement surfaces and slid in the direction in which they diverge to secure the outer lid firmly to the container.

Abstract: In a variable reluctance electric drive system motor the fractions of a cycle during which the winding inductance of a phase increases with movement in either direction are such that the motor is self starting in either direction. The timing of the power converter in relation to the cycle of inductance is such that the current increases from its minimum value to substantially its maximum value while the winding inductance is substantially at its minimum value and thereafter substantially decreases before the power converter disconnects the winding from the supply. This can be achieved by making the switch-on and commutation of current occur at predetermined positions so related to the variation of inductance that the peak current ip at maximum power and maximum speed, is greater than I, where I=E/(R+dL/dt), E is the supply voltage, R the winding resistance and dL/dt is the maximum rate of increase of inductance before the commutation point.

Abstract: A synthetic pulp separator for a lead acid battery, the separator having two or more plies and a ribbed profile the surface adapted to face the positive having a higher content of synthetic pulp than the other surface.

Abstract: A lead alkaline earth metal alloy comprising lead, calcium, barium or strontium or mixtures thereof in an amount of 0.075A/40% to 0.13A/40% by weight where A is the atomic weight of alkaline earth metal 0.005% to 0.05% magnesium and preferably 0.005% to 0.01% aluminium is disclosed and has improved corrosion resistance combined with tensile strength as compared to alloys with magnesium and aluminium contents outside these defined ranges.The alloy is useful for grids in lead acid electric storage batteries.

Abstract: For use in an automatic electric battery charger, a charge controller which monitors the rate of rise of battery voltage, and terminates the charge when the rate of rise falls below a predetermined value, typically 11 mV per cell in 45 minutes for a lead-acid battery. The battery voltage is monitored by combining with it a ramp signal which changes, in the opposite sense to the rise in battery voltage, at a rate just sufficient to offset a rise in battery voltage of the said predetermined value. In the preferred embodiment, the combining step is performed by a summing amplifier, and a bias signal is also fed to the summing amplifier; this bias signal is shifted, in one direction only, to hold the output of the amplifier between narrow limits as long as the rate of rise of battery voltage is greater than the predetermined value.

Abstract: A converter includes a resonant oscillatory tank circuit comprising a capacitor and an inductor, at least one switching circuit including a solid state switching device in parallel with a diode connected to apply a predetermined potential difference from a DV supply to the inductor, and synchronizing means responsive to the oscillation of the oscillatory circuit for switching on the switching means for a fraction of a cycle when the instantaneous value of the oscillatory potential difference across the inductor is already not less than a predetermined value, to delay the fall of the said oscillating potential difference and inject energy from the supply into the oscillatory circuit, and a load circuit coupled or connected to the tank circuit in series with the inductor.