Abstract: The invention refers to a gas-tight, maintenance-free high capacity lead accumulator with a sulphuric acid thixotrope (13) as electrolyte. To ensure operatability of the accumulator in upright as well as in horizontal position, the liquid electrolyte released under certain charging conditions has to be collected. For this purpose layers of fibrous web (10, 22) of highly porous and absorbing material are at least partially provided at the edges of the accumulator and above the plate group (1) which temporarily store liquid electrolyte and again release it.

Abstract: The invention is directed to a sealed, maintenance-free lead-acid storage battery of high capacity employing a thixotropic sulfuric acid gel as the electrolyte.In order to permit horizontal mounting without incurring the risk of escaping sulfuric acid during the charging process, the lower portion of the free gas space between electrode plates (1, 2) and housing lid (7) including the positive terminal (3) is filled with foamed material (9) which is preferably separated by means of a parting angle piece (10, 11) from the upper free gas space (6) including a pressure relief valve (8).

Abstract: The invention is directed to a lead calcium alloy for electrode grids, the alloy being substantially antimony-free. Copper and/or sulphur in small amounts are added to said alloy in order to significantly improve the casting properties, the mechanical and the corrosion properties.

Abstract: The invention is directed to a control circuit for controlling the current of a welding transformer integrated in an industrial robot. For the purpose of achieving a simpler, more accurate and more reliable detection of contact between the welding tongs (4, 5) and the parts (11, 12) to be joined by welding, there are provided a high-frequency generator (1) for supplying measuring current to the secondary circuit (2) of the welding transformer, an impedance measuring circuit (3), an additional impedance (7) for increasing the impedance of the secondary current (2) to high frequency, an interrupter circuit (8) for interrupting the welding current, and a comparator for enabling the welding current merely in the presence of a differential voltage signal which corresponds to complete contacting of the two parts to be joined by welding.

Abstract: The invention relates to a precursor for an electrical storage lead battery which can be converted into an operative storage battery by the mere addition of a sulphuric acid electrolyte. This precusor which has an unlimited shelf life consists of positive plates, of negative plate dispersed therebetween and of separator plates inserted between adjacent positive and negative plates and of a housing encasing the plates in dry condition. These separator plates consist of a densely compressed compact containing(a) 70 to 100% of pulverized silicon-dioxide or of another pulverized material which is capable of absorbing the liquid electrolyte and of being converted thereby into a pressure-resistant gel and(b) 0 to 30% of fibres of glass or any other acid-resistant and oxidation-resistant material.

Abstract: To prevent the formation of deposits of lead dross and the like due to oxidation of the molten lead, at least a portion of elements defining the pump chamber, for example the cylinder, and the piston are made as an iron casting which has been subjected to a salt bath nitriding treatment to produce a hard surface layer with excellent resistance against the deposition of lead dross.

Abstract: Metallic and/or thermoplastic components of a storage battery are fluid-tightly connected by means of a multicellular thermoplastic sealing member formed by injection of a foamable thermoplastic resin composition containing a foaming agent into a cavity provided between the components to be connected together.