Patent GB-1091322-A (GB)
Title: Improvements in or relating to vehicle suspensions
IPC: B60G17/00
Filed: 1965-07-30
Abstract: 1,091,322. Pneumatic springs; road vehicle suspension systems. H. TEVES, E. A. TEVES and M. TAUSEND, [trading as ALFRED TEVES MASCHINENUND ARMATURENFABRIK KOMM. GES.]. July 30, 1965; [Oct. 30, 1964], No. 32668/65. Heading F2S. An accumulator unit for vehicle air spring suspensions and which varies the pressure of the air spring or springs, in accordance with the loading of the vehicle so that the vehicle body is maintained at a substantially constant height comprises an air accumulator compartment 10 which is connected to one or more of the air springs, not shown, through a connection 12, a coolant vapour compartment 16 which is separated from the air accumulator 10 by a rolling diaphragm 13 having a sheet metal support 14 with a filling element 15 and which is located above a central heating element 23 in which heating element channels 24 are coiled, and a liquid coolant compartment 11, which is separated from an air spring chamber 30 at the lower end of the unit by a rolling diaphragm 29. A displacing element 27 has sides 26 which project upwardly through segmental passages 25 between the heating element and a ring 7 and a cylindrical portion 28 which is secured to the rolling-diaphragm 29. The open heating channels 24 in the heating element are closed by a plate 37 and the whole of the heating system, which includes pipes 21, 22 connected to the I.C. engine coolant circuit and housed in the channels 24, is enclosed in a plastics envelope 38 so that only the top surface 39 is exposed to coolant from the compartment 11, the envelope 38 having a neck 40 on which the cylindrical portion 28 of the displacing element 27 is slidably guided. When the spring is in operation cooling fins 20 on an outer casing 2 continuously resume the heat supplied by the pipes 21, 22 cooling vapour, condensing in the annular space 17 between the casing 2 and the inner wall 9, dripping down the inner surface of the casing 2 and passing back to the liquid coolant through bores 19. When the vehicle is travelling with light load the pressure in each suspension spring is low and the diaphragm 13 is correspondingly high in the accumulator 10, a compression spring 36, located over a guide neck 35 for a plunger 34 carried by the diaphragm support 14, and received at its upper end, in a recess in the filling element 15, being expanded, the heating element 23 not being flooded with coolant, and the air spring 30 being cooled off by the slipstream. As the load increases the diaphragm support 14 and the plunger 34 move downwards the latter pumping coolant out of the neck 40 through a bore 42 so that it floods the heating element surface 39. The vaporization of the coolant increases the pressure in the chamber 16 which raises the diaphragm 13 air being driven from the accumulator 10 into the suspension spring which is expanded to its original length. The increased pressure in the chamber 16 also forces the displacing-element 27 downwards against the pressure of the air spring 30 so that flooding of the surface 39 is assisted. As the outside temperature decreases or increases the volume of the vehicle air suspension and the accumulator 10 and spring 30 correspondingly decreases or increases so that the flooding of the heating surface 39 with coolant is controlled to compensate changes in the distance between the vehicle frame and axle as the result of changes in the outside temperature. The accumulator unit can be used with the interposition of hydraulic transmission of force. An electric heating coil can also be incorporated as an initial heater before the I.C. engine coolant has had time to become sufficiently heated.