Abstract: A vented filling plug for an electric storage cell has a vent path including a flame trap through which gas may enter or leave the cell arranged so as, in use, to communicate with the interior of the cell at a point above the normal electrolyte level. The flame trap includes a liquid trap defined by a trough and a tubular partition, and a ceramic partition. The plug also has a filling path through which electrolyte may be poured into the cell arranged so as, in use, to communicate with the interior of the cell at a point below the normal electrolyte level. The filling path includes a liquid trap defined by a trough and a partition below the normal electrolyte level.

Abstract: An automatic electric battery charging apparatus which includes terminating means comprising a bistable circuit having set and reset conditions, means for supplying a control signal dependent on battery voltage on charge through a capacitor to an input of the bistable circuit, so as to set the circuit when the battery voltage increases, capacitor charge adjusting means operative when the bistable circuit is set, for supplying current to the capacitor to adjust the charge of the latter until it re-sets the bistable circuit, a timer arranged to be reset by the bistable circuit in its set state, and means to terminate the charge or reduce the average charging current if the timer is not reset within a predetermined time. Thus the input potential to the bistable has a sawtooth waveform while the bistable is reset the capacitor charge remains unaltered, so that the bistable input potential follows that of the battery until the bistable is set.

Abstract: There is disclosed a sealed lead acid button cell having a moulded acid resistant polymer case formed in two portions each portion having a central boss with a passage leading into the cell, and a metal plug located in the said passage, the inner end of the plug being electrically connected to the electrode located in that portion of the case, and a cap made of a metal harder than the metal of the said plug surrounding the central boss and squeezing it against the plug and the cap being electrically connected to the plug. The cap may thus be crimped around the boss or may be a force fit thereon. The case is provided with a pressure relief vent to allow gases to vent under service conditions.

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 series 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 only 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.

Abstract: An automatic electric battery charger which detects when the battery is fully charged by monitoring the rate of rise of battery voltage; when the rate of rise falls below a predetermined value, the charge is terminated. The rate of rise of voltage is detected by comparing an unprocessed battery voltage signal with a signal which follows the battery voltage signal with an exponential lag having a time constant of about 45 minutes. With a low rate of rise of voltage, such as occurs when the battery approaches the fully charged state, the lagging signal will tend to catch up with the unprocessed signal, and when the difference falls below 11 mV per cell, the charged is terminated.In the preferred embodiment, the signal processing is digitally implemented, using a microprocessor.

Abstract: There is disclosed a plant for pasting battery plates comprising a pasting machine comprising a flat conveyor belt and paste applying means for forcing paste into a grid conveyed on the conveyor past the said paste applying means, grid feeding means, and a transportable hopper and mechanical discharge means for mechanically discharging paste into the inlet to the pasting machine, paste recycling means adapted to mechanically collect paste applied to the conveyor and to convey it back to the inlet to the pasting machine, and a drying oven.

Abstract: The automatic electric battery charging apparatus includes at least one timer, a voltage comparator arranged to compare a reference voltage, referred to herein as a staircase voltage, with a control signal varying with battery voltage, jacking means rendered operative by the timer when a first predetermined time interval has elapsed and serving to repeatedly increase the staircase voltage step-by-step relatively to the control signal, by equal steps, so long as the control signal exceeds the reference voltage, and terminating means for initiating the termination if the staircase voltage exceeds the control signal before the jacking means have exceeded a predetermined number of steps from the start of their operation.

Abstract: A method of making a multitubular sheath comprising providing a porous multitubular fabric impregnated with thermoplastic or deformable polymer, continuously feeding the fabric onto an array of parallel metal rods, one tube to each rod, the rods having straight sizing portions, while holding the rods in a fixed position, the rods having substantially the same cross sectional area over the whole of their length, the fabric at least immediately prior to the sizing portions being substantially at ambient temperature, heating the fabric on the sizing portions so as to permit the fabric to conform to the rod, thereafter cooling the fabric on the rods to solidify or the deformable composite material to set to shape and the tubes to become self supporting, feeding the fabric off the ends of the rods and cutting it to the required length.

Abstract: An electric cell has a terminal post of which one end is of reduced diameter and passes through a hole formed in a wall of the cell and at least a part of which is screw threaded and carries a nut. The terminal post has a shoulder which is drawn by the nut towards the inner side of the wall. Between the shoulder and the wall is a cup washer having a recess which engages a projection carried by the wall. A locking washer is interposed between the cup washer and the shoulder so that rotation of the terminal post is prevented.

Abstract: A battery charger which provides a constant current charge during a first part of the charging period and a taper charge during the remainder of the charging period. The taper charge characteristic is obtained by decreasing a set value for the charging current by a step of predetermined size each time the battery voltage has risen by a step of predetermined size, provided that the battery voltage is above a certain threshold; below this threshold, the set value has its maximum value, resulting in the constant current part of the charge. The charging current is regulated to be equal to the set value, regardless of variations in mains supply voltage. The charge is terminated when the time between steps in battery voltage exceeds a predetermined value.

Abstract: A controller for incorporation in a battery charger to limit the overall length of the charge, and also to provide short topping-up charges at intervals after the main charge has been completed, if the battery is left connected to the charger. The controller allows the limit on the length of the charge to be set to either 10 or 141/2 hours; the subsequent topping-up charges then start at intervals for 10 or 141/2 hours, and last for about 40 or about 55 minutes, depending on the setting of the main charge time limit. The controller is illustrated in conjunction with a charger control circuit which terminates the main charge when the rate of rise of battery voltage falls below a predetermined value, and this is normally expected to occur before 10 (or 141/2) hours have elapsed, leaving the time limit set by the controller as a safeguard.

Abstract: A system for erecting elevated floors where a first support floor with a drawworks thereon is connected to one end of a base structure by two pair of parallel spaced pivotable links and a second support floor is coupled to the opposite end of the base structure and by two pair of parallel spaced pivotable links. In accordance with the invention a strong back is erected about midway of the length of the base forming a rigid frame and supporting elevated sheaves at each side of the base structure. A pair of cables are adapted to pass over said sheaves, one on each side of said base structure and connect first to said first floor for erection and then to said second floor for erection.

Abstract: There is disclosed an electrode structure for an electrochemical cell comprising a fibrous support made of organic polymeric material, which is 0.1 to 3 mm. thick, carrying a pattern of solid conductors extending over the surface of the porous support from a current take off region to regions spaced therefrom, and containing electrochemically active material deposited on the fibrous support, in contact with the conductors, in an amount of at least 0.1 grams/sq. cm/mm thickness in such a manner that electrical energy produced by the electrochemical reaction can be conducted out of the electrode. Also disclosed are methods and apparatus for making the structure.

Abstract: There is disclosed a battery electrode structure made of a lead-calcium-tin alloy comprising 0.075 to 0.13% by weight calcium, 0.005 to 0.99% by weight tin and 0.0001% to 0.1% by weight aluminium, the balance being substantially lead.

Abstract: There is disclosed apparatus for filling enveloped plates for batteries with active material which comprises at least one filling station comprising means for supporting the envelope of a plate assembled on its current conducting element in a substantially vertical plane and a filling manifold adapted to introduce a slurry of active material into the envelope of a plate located in the said supporting means, the apparatus further comprising, a slurry storage tank adapted to contain a supply of active material slurry and provided with agitating means for maintaining the active material in the storage tank in suspension as a slurry, and delivery means for delivering slurry from the storage tank to the manifold of a selected filling station.

Abstract: A sealed lead acid cell is disclosed which has electrodes comprising metallic supports which minimize the evolution of hydrogen and resist deformation under their own weight, and which are separated by at least one layer of separator material, the capacity of the negative electrodes is arranged to be at least as great as the capacity of the positive electrodes, the thickness of the electrodes is less than 3mm, the thickness of the separator is in the range of 10% to 200% of the thickness of the electrodes, and the volume, E, of electrolyte in the cell in relation to the sum of the pore volume of the separators, X, and the pore volume of the positive and negative active materials, Y, is not greater than 2X + Y.

Abstract: A cell rack includes two generally planar rectangular end elements and any number of spacer elements of spider form. Each rack element affords horizontal surfaces for supporting an adjacent cell and a number of vertical surfaces for spacing the cell from the rack elements and further vertical surfaces for restraining lateral movement of the cells.The cells and racks elements are held together in a single unit by four tie rods which pass through respective corners of the rack elements.

Abstract: Automatic battery charging apparatus in which a control signal is generated by subtracting a signal representing a fraction of the mains supply voltage from the battery voltage so that the control signal represents the state of charge of the battery irrespective of variations in the mains voltage. The charge is terminated when the rate of rise of the control signal falls below a predetermined value; this condition is sensed by sampling the output frequency of a voltage controlled oscillator whose frequency is directly proportional to the control signal. In one arrangement the output frequency is fed to an up-down counter for a sampling period (2 minutes) with the counter counting up and then, after an interval of 30 minutes, the output frequency is fed to the counter for a further sampling period (1 minute 55 seconds) with the counter counting down. If the counter fails to return to zero at the end of a down count the charge is terminated.

Abstract: There is disclosed a method for preparing enveloped plates for batteries which comprises introducing an active material composition into the porous envelope of an enveloped plate when the envelope is assembled on the current conducting element of the plate characterized in that the active material composition is introduced into the envelope as an aqueous slurry, which has a degree of sulphation in excess of 50% and a rotating vane viscometer torque value (as herein defined) of not more than 0.2 lbs ft. at 20.degree. C, the said aqueous slurry being introduced into the envelope at a pressure of less than 5 psi until the envelope is filled with the composition, liquids issuing through the walls of the envelope, the pressure then being allowed to rise to a value above 5 psi but not in excess of 70 psi, the pressure there after being released. A variety of suitable active material compositions are described together with apparatus for carrying out the method.

Abstract: An electric accumulator having an alkali metal as the reactant at the negative electrode, and a cationically conductive separator physically separating the reactant at the negative electrode from a reactant at the positive electrode, while permitting passage of cations of the alkali metal therethrough, characterized in that the reactant at the positive electrode comprising a mixture which, in the fully charged state, comprises 5 to 75 mole % of aluminium chloride and 95 to 25 mole % iron III chloride.