US3076479A - Expansion means for self-contained liquid circulating systems - Google Patents

Description

Feb. 5, 1963 3,076,479

K. OTTUNG EXPANSION MEANS FUR SELF-CONTAINED LIQUID CIRCULATING SYSTEMS Filed NOV- 2, 1960 United States Patent 3,076,479 EXPANSION MEANS FOR SELF-CONTAINED LIQUID CIRCULATING SYSTEMS Kai Ottung, 8 Askebyvej, Virum, Denmark Filed Nov. 2, 1960, Ser. No. 66,827 1 Claim. (Cl. 138-30) The present invention relates to an expansion device for self-contained liquid circulating systems, particularly for use in the water cooling system of a motor vehicle.

Circulating systems, in which an expansion vessel is incorporated, are already known, this vessel being either included in the actual path of circulation or connected thereto by a communicating pipe. The expansion of a liquid due to increase in temperature is accompanied simultaneously in such a system by a rise in pressure with the result that the material of the components of the circulating system and of the associated expansion tank are subjected to not inconsiderable extra stress.

The present invention eliminates this drawback by including in the circulating system, or in a chamber in communication therewith, a readily compressible container enclosing a space which is inaccessible to liquid but which is in communication with the ambient air. In this arrangement, on expansion of the liquid, the container can be compressed without any resistance so that expansion will not cause a rise in the pressure head, or raise it only to a slight amount depending upon whatever slight resistance is offered by the container.

Should the liquid continue to expand after the container has been compressed completely, then a considerable pressure rise will naturally occur.

In one embodiment of the invention this rise in pressure is controlled to a desirable extent by the inclusion in the circulating system, or inside the chamber, of a second, likewise compressible but closed, air-filled container. When the first container which communicates with the outside atmosphere has been compressed completely, should further expansion of the liquid occur, it will entail a considerable or slight amount of compression of the closed container so that the ensuing pressure rise will be uniform.

The location of one of the two compressible containers in a special chamber is an advantage because any contaminating impurity carried into the chamber by the expanding liquid will readily settle since the liquid in the chamber is relatively stagnant. Impurities can thus progressively be removed from the circulating system proper.

The invention is illustrated in the accompanying drawings in which:

FIGURES 1, 2 and 3 are sectional views showing an expansion device in accordance with one embodiment of the invention and illustrating three stages in the expansion of the liquid in the system, and

FIGURE 4 is an alternative embodiment of the expansion device.

Referring to FIGURE 1 the expansion device comprises a chamber 1 having a connection 2 to enable it to be connected to a circulating system (not shown) such as the water cooling system of a motor vehicle. In one wall of the chamber is a flanged vent pipe 3, by means of the flange 4 of which a compressible container 5 in the form of a ball or bladder is fixed in position within chamber 1 so that the interior of said ball or bladder is cut oil i.e. inaccessibly to the liquid in the chamber 1 but is in direct communication with the ambient air. The chamber 1 also contains a second compressible container 6 which is completely closed and filled with a gas or air, for instance atmospheric air.

FIGURE 1 shows the expansion means as it appears when the liquid in the system is cold, whereas FIGURE 2 shows the manner in which on a rise in temperature of the liquid in the system the shape of container 5 is caused to change, container 6 continuing to remain completely taut.

Any further rise in temperature causes expansion to continue until the container 5 is completely compressed as shown in FIGURE 3. The manner in which the container 6 now begins to be compressed as the pressure in the system rises above the outside atmospheric pressure at more elevated temperatures can also be seen.

In the embodiment shown in FIGURE 4 the chamber 7 consists of rubber or similar material and is externally reinforced and stiffened by a rigid tube 8. At one end the chamber 7 is provided with a connection pipe 9: at its other end it is formed with an opening 10 to which a flexible bellows 11 is fixed in such a way as to enclose the opening, the other end of the bellows being sealed by an end plate 12. The bellows 11 is subdivided into two separate compartments 14 and 15 by a partition wall 13, the operation and function of these chambers being the same as that of the two containers 5 and 6 in FIG- URES 1 to 3.

The invention is particularly adapted for use in the water cooling systems of internal combustion engines of motor vehicles and may be housed in the radiator.

I claim:

A thermal expansion compensating device for a closed cooling liquid circulation system of an internal combustion engine, comprising, in combination, a first liquid displacing container surrounded at least partly by said cooling liquid, said container communicating with the atmosphere and having a flexible wall so as to be operative to compensate for limited thermal expansion of said cooling liquid without substantial increase of the pressure thereof, and a second liquid displacing container surrounded at least partly by said cooling liquid, said second container being a closed gas filled container having a flexible wall so as to be compressible by the pressure of said liquid when the thermal expansion thereof exceeds said limited thermal expansion.

References Cited in the file of this patent UNITED STATES PATENTS 852,150 Whitney Apr. 30, 1907 2,132,952 Hewitt Oct. 11, 1938 2,497,020 Singer Feb. 7, 1950 2,638,932 Alexander May 19, 1953

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