Abstract: Sheet material for cleaning the head of a magnetic storage disc drive, comprising a sheet of head-cleaner material which serves to clean such a head, the head-cleaner material being laminated to a backing sheet of stiffening material. This composite sheet material may be cut to the shape of a magnetic storage disc and contained within a protective cassette housing.

Abstract: A viscosimeter comprising a Zahn cup, a supply tank arranged to supply a liquid, the viscosity of which is to be measured, to the Zahn cup, a control mechanism operable to stop the supply of liquid to the Zahn cup once the latter has been filled to overflowing, and a timing mechanism arranged to measure the time taken for the Zahn cup to empty following operation of the control mechanism. The timing mechanism comprises an emitter-detector pair positioned to direct a sensing beam across the flow path of liquid which leaves the Zahn cup and a timer connected to commence a time measurement at the instant of operation of the control mechanism, and to stop the measurement at the instant the detector of the emitter-detector pair indicates an absence of liquid therebetween.Such a viscosimeter may be used in the measurement of the viscosity of ink used in a printing process, and the control of the viscosity in dependence upon that measurement.

Abstract: A cushion for cooling an organ of the body during surgery. The cushion is flexible and of open form to allow cooling fluid to flow into it and out of it. A flexible tube extends from the cushion for draining off cooling fluid from the cushion and regions adjacent thereto.