Abstract: A vacuum pump is provided comprising a pumping mechanism, a drive shaft for driving the pumping mechanism and a gear box connected to the drive shaft for rotating the drive shaft. Pressure control means are provided to define a path to allow fluid to flow from the pumping mechanism to the gear box in order to reduce the pressure difference therebetween. A reservoir is located within this path for collecting oil passing along the drive shaft from the gear box towards the pumping mechanism. In use, this enables pressurized fluid flowing from the pumping mechanism towards the gear box to urge oil which has collected in the reservoir, towards the gear box.

Abstract: An apparatus and process for operating a rolling mill having at least two rolls rotating at different speeds to produce a continuous strip material having a substantially constant final thickness comprises a mechanism for controlling the magnitude of the compressive force between the rolls in response to the ratio of the incoming strip speed to the outgoing strip speed. A mechanism is provided for comparing the ratio of the strip speeds to a ratio of the roll speeds and for adjusting the compressive force magnitude until the two speed ratios are substantially equal. In this manner, the amount of off-stage strip material produced during mill start-up is reduced and process stability and gage control during steady state operation is enhanced.

Abstract: A process is disclosed for joining narrow width thin gage metal or alloy strip end to end to form an elongated coil. The trailing end of a first strip segment and the leading end of a second strip segment are cut so as to match when placed in a butting relationship and to establish a joint between the strips. A preselected gap is established between the butting ends and a braze material is inserted in the gap. After heating to braze the strip segments together, the brazed joint is hammered to reduce the joint geometry to that of the parent metal strip segments.

Abstract: The disclosure teaches a method for the manufacture of hollow articles useful as heat exchangers including the steps of rolling together two sheets of metal with at least one metal tube sandwiched therebetween to form a bonded assembly. The metal tube is subsequently expanded by the introduction of pressure therein to form an internal passageway.