Patent GB-432048-A (GB)
Title: Improvements in or relating to a viscosity responsive device for controlling the flow of fluid through a plurality of paths communicating with a conduit for example in alubricating system for internal combustion engines
IPC: F16N29/02
Filed: 1934-02-07
Abstract: 432,048. Lubricating. LUBRICATION CONTROL CORPORATION, 105, South La Salle Street, Chicago, U.S.A.-(Assignees of Booth, H. T.) Feb. 7, 1934, No. 4047. Convention date, Feb. 7, 1933. [Class 12 (iii)] [See also Group XIX] A viscosity-responsive device for controlling the flow of fluid through a plurality of paths communicating with a conduit, as in the lubricating system of an engine, comprises a chamber through which a portion of the fluid is caused to flow so that the pressure therein is a function of the viscosity of the fluid, said chamber having a movable wall connected to a valve adapted to control the flow of fluid through said paths and means for opposing movement of said valve in one direction. The Figure shows the position of the parts in the oil sump or well 12a when the engine is at rest. A peripheral groove 32 in the skirt of a piston 30 is in full register with a bye-pass 29 from the delivery side of the pump, and a port 21 in the cylindrical casing 17 is open to the space between the heads 23, 24 of a piston valve 22, the port 25, to which is connected a pipe 16 from an oil cooler or radiator underneath the engine, being closed. All spaces within the casing 17 are full of oil. On starting the engine, oil is drawn in through the port 21 and delivered to the bearings through the pipe 18. Oil is also forced by way of the pipe 29 into the piston 30 and thence through the friction tube 35 and orifice 37 into the well. The resistance offered by the tube 35 varies with the viscosity while the orifice 37 is such that flow through it is independent of the viscosity of the fluid. The increased pressure on the left of the piston tends to move it to the right against the back pressure due to the resistance of the orifice 37 and the pressure of the spring 36. Such movement cuts down the oil flow through the ports 31 and continues until the pressure differential across the friction tube equals the strength of the spring 36. When the oil viscosity, as at starting, is high, the flow through the tube is low, and the back pressure between the piston 30 and the head 23 is low and insufficient to move the valve 22 away from the stops 28 against the spring 26. The pipe 16 to the radiator is thus closed. After a period the oil becomes heated and the flow through the tube 35 increases packing up a back pressure and moving the piston 22 to the right so that cooler oil is drawn in through the pipe 16 to mix with the oil from the well. A balance is subsequently struck and a predetermined viscosity maintained. A pipe 38 may lead to a pressure gauge on the dash board graduated in terms of viscosity. The orifice and friction tube may be arranged in the reverse order. Several modifications are described including one in which the orifice is arranged in the closed end of the piston 30 and the friction tube in the skirt of an additional piston connected to the valve 22, and another in which the spring 36 is arranged between the piston 30 and the end 34 of the casing in which end is located the orifice. In further modifications the walls of some of the chambers are formed by bellows.