Abstract: An electric motor controller comprises a circuit for selecting between driving and braking an electric motor in accordance with the health or otherwise of a pair of main electric motor control switches (14 and 16). In a preferred embodiment the health of the switch is determined by the voltage (A) between the switches. The controller also comprises apparatus for detecting the sense of movement of the motor. In the event that the motor is moving in a sense opposite to that selected, the apparatus increase field current to reduce the armature current thereby increasing the braking effect of the motor. Also in the controller are apparatus for changing from armature to field current control and vice versa, in response to a given magnitude of control signal. In order to provide an unambiguous change-over, a lockout circuit is provided to inhibit change-over in a transition region. The lockout circuit maintains the mode of control to above/beneath the change-over level when changing from one level to another.

Abstract: A sealed lead acid recombination electric storage cell comprises a container containing alternating positive and negative plates separated by separators. Each separator includes reinforcing means extending over substantially its entire area and constructed to define a plurality of apertures and being surrounded by microfine glass fibre material. The plates and separators are under a compressive force and the reinforcing members are so constructed and arranged that the major proportion of the compressive force is transmitted through the reinforcing members while the major proportion of the area of the plates is contacted by the glass fibre material.

Abstract: A lead acid recombination cell of motive power type comprises a sealed container containing negative plates alternating with tubular positive plates comprising a plurality of parallel tubes of porous material which contain active material and along the interior of each of which a conductive spine extends. Adjacent plates are separated by compressible fibrous absorbent material and the cell contains substantially no free unabsorbed electrolyte whereby substantially all the electrolyte is absorbed in the plates and separator material.

Abstract: An electric storage battery specifically designed for standby operation is described. The battery is provided with terminal surfaces extending at an acute angle to the top of the battery lid which permits a flat support surface and handle means designed into the lid. Such battery structure permits a plurality of batteries to be stacked and allows air circulation to cool the stack.

Abstract: A multi-phase switched variable-reluctance motor having a number of phase windings (A, B, C) each connected in series with at least one main thyristor (1,2,3,4,5,6) across a D.C. supply (V.sub.5) has commutating means (23) responsive to the current in the different windings, the angular position of the rotor, the state of the main thyristors, the motor speed, and the desired operating condition, to control the firing and commutation of the main thyristors. Two modes of operation described in detail are a chopping mode in which chopping is controlled independently in two adjacent phases at the same time, and a single pulse mode with free-wheeling.

Abstract: An electric storage battery includes a rectangular container sealed by a lid. The lid affords spaced upstanding formations extending adjacent respective opposed side edges of lid and support means comprising spaced handle webs extending between the upstanding formation. The handle webs afford a flat upper surface which is vertically spaced from the remainder of the lid and adapted to support a further such battery. The outer edges of the handle webs are spaced inwardly from the two opposed side surfaces of the container when viewed in plan.

Abstract: A method of manufacturing a recombination electric storage cell includes pasting positive and negative electrodes with damp active electrode material and forming a cell pack of alternating positive and negative electrodes interleaved with separator material. The cell pack is inserted into a plastics bag while the active electrode material is still damp and the electrodes are then cured by subjecting them to a temperature in excess of 25.degree. C. so as substantially to dry them while within the bag. The cell pack is then inserted into its final outer container.

Abstract: A grid array for use in assembling a multicell electric battery comprises a plurality of grids preferably arranged in two spaced parallel lines, adapted to provide a plate for every cell of the battery. Each grid is connected to one or more adjacent grids by a combination of integral bridge pieces and sufficient temporary links to maintain all the grids of the array in their desired configuration.

Abstract: A method of manufacturing recombination electric storage cells includes assembling a plurality of cell packs comprising alternating positive and negative electrodes interleaved with compressible fibrous absorbent separator material. Each cell pack is placed in a respective open plastics bag and the cell packs are constrained to occupy a volume which is less than their natural volume. The cell packs are then immersed in electrolyte thereby saturating the electrodes and separator material and then electrolytically formed by passing an electric current through them. The cell packs are subsequently inserted into their final outer container.

Abstract: A recombination lead acid battery includes a plurality of cells comprising alternating positive and negative plates interleaved with separator material. Every alternate plate in the two electrical end cells constitutes an unipolar plate connected to a terminal pillar and each remaining plate constitutes one half of a bipolar pair of plates connected by means of an integral bridge piece to its other half in an adjacent cell. The bridge pieces together constitute intercell connectors and those cells which are directly connected by an intercell connector are spaced apart only by the intercell connector and separated only by an air gap while those cells which are not directly connected by an intercell connector are separated by an intercell partition integral with the battery container.

Abstract: A method of assembling a multicell lead acid battery includes forming a laminated structure from a plurality of flat plate arrays. Each array comprises positive and negative plates connected to at least one further plate in the same array by at least one link. The arrays are superposed so that each plate is in registry with a plate of opposite polarity in the adjacent array and separated from it by separator material. One or more cuts are made to sever selected links to form a plurality of stacks of plates of alternating polarity which constitute the individual cells in the finished battery with each plate, with the exception of every other plate in the two electrical end stacks of plates, electrically connected by one or more integral links to only a plate of opposite polarity in the same array and with every alternate plate in the two electrical end stacks of plates connected to no other plate. In the finished battery each plate in each cell lies in a common plane with one plate in every other cell.

Abstract: A lead acid battery comprises two spaced parallel rows of cells connected in parallel, one plate in each cell lying in the same plane as one plate in every other cell. Every alternate plate in the two electrical end cells is a unipolar plate connected to a terminal pillar while every remaining plate is one half of a bipolar pair of plates connected to its other half in an adjacent cell, preferably in the other line of cells, by an integral bridge piece.

Abstract: A clamp for use in the assembly of multicell electric storage batteries comprises two spaced opposing clamping members each including a plurality of clamping elements which are connected but spaced apart by a gap. The clamping elements are arranged in two spaced parallel lines and are each adapted to contact a surface of a respective cell pack of a battery. Biassing means connects the two clamping members and is adapted to urge each clamping element of each clamping member towards a corresponding clamping element on the other clamping member.

Abstract: An alkaline electric storage cell comprises a container within which are positive and negative pocket plates separated by composite separators. Each separator has a lower portion which is of conventional ladder type having a substantially open area and an upper portion which is a strip of absorbent fibrous material. The cell is filled with electrolyte up to a level which is slightly above the bottom of the strips. The high discharge rate voltage of the cell is scarcely impaired by comparison with a conventional cell, but the oxygen that is evolved at the end of charge is recombined at those portions of the negative plates which are above the electrolyte level but retained moist with electrolyte by the absorbent strips. The cell thus loses no electrolyte and is of no-maintenance type at charging rates of up to C/60 or more.

Abstract: A multicell electric storage battery includes a rectangular section container containing a plurality of cells extending along the length of the container. A lid is common to all the cells and has a depending skirt which is sealed to the container. The battery has two top terminals extending through the lid and situated on the central longitudinal axis of the lid and two side terminals which are connected to a respective plate strap by a respective connector member which passes through and is sealed to the walls of a housing which projects upwardly from the lid and whose interior is sealed from the interior of the battery and one of whose outwardly facing side walls carries a side terminal.

Abstract: A method of making an electrode for a lead acid battery which comprises compressing an active material composition into adherent contact with an apertured electrical conductor characterized in that compression is applied to the active material and electrical conductor so as to compress the active material to planar form adherent to the conductor except in the region where it is wished to form an aperture through the active material where compression is not applied or is applied to a lesser extent such that the active material can be readily displaced from the non-compressed region by means which do not displace the active material from the remainder of the compressed electrode.

Abstract: A variable reluctance motor control system has for each main phase winding (11) a power converter circuit including a main thyristor (12) across a D.V. source (50) and a commutating circuit including a capacitor (51,52) and a commutating thristor (16), arranged to resonantly reverse the charge on the capacitor in preparation for energizing the next main phase winding (21) by passing a current through the other main phase winding.

Abstract: An adjustable lamp mounting assembly for two lamps 12, 12A, which are each connected to a body 10 by a pair of arcuate rods 14. The arcuate rods 14 of lamp 12 each fit snugly into one of a pair of slots 16 formed in a face 18 of the body 10. The rods are retained in the slots 16 against the ends of the slots by a single resilient spring strip 20, which lies on the opposite side of the face 18 to the lamp 12. The resilience of the spring strip 20 holds the arcuate rods 14 against the ends of the slots. The arcuate members 14 can slide in the slots 16, in the direction shown by arrow 26 to rotate the lamp 12. The arcuate rods 14 are connected to the lamp 12 by a pair of housings 22, and the lamp 12 is mounted to turn about bearings in the housings 22 about the pivot axis 24.