US 3388825 A
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June 18, 1968 T. B. MlLLE R FILTER PROTECTED RADIATOR CAP Filed Dec. 22, 1966 I N VEN TOR fix?) 15. WW I Ai TORNH.
United States Patent ABSTRACT OF THE DISCLOSURE This invention relates to closures and more particularly to automobile radiator caps in each of which a main closure valve and a small vent are embodied for determining the pressure to be contained.
Background of the invention Pressure caps are generally used on automobile radiators to retain above ambient pressures in the interest of cooling efficiency and for the retention of coolant despite expansion of the latter. Each cap must effect a main closing of a filter neck on a radiator and provide for automatic venting when a predetermined coolant pressure is exceeded and often upon the attainment of too low a pressure.
It has been found that in the use of such a cap, venting will occur through a vent or small vent valve when an excess coolant pressure is reached and subsequently some small particle of dirt often becomes lodged in the vent or vent valve with the result that the vent or vent valve is prevented from closing, and the purpose of the closure is defeated.
A typical radiator cap giving rise to the problem is disclosed in the United States Patent 2,139,395 granted Dec. 6, 1938, in the name of Nelson Walker.
Summary of the invention Description of the drawings FIGURE 1 shows a cross sectional view of a radiator cap and a conventional radiator filler neck with a filter element combined with the cap as one embodiment of the present invention;
FIGURE 2 is a sectional view looking in the direction r of the arrows 2-2 in FIGURE 1; and
FIGURE 3 is a perspective view of a cage shown in FIGURES 1 and 2 as a retainer for the filter element.
Description of the preferred embodiment The top of a radiator tank is depicted at 10 in FIGURE 1 and this top is fitted with a conventional filler neck 12 which is enlarged to a larger diameter as at 14 resulting in an inner annular shoulder or seat 16. The top end of the neck 12 bears an annular outwardly extending flange 18 which cooperates with two oppositely disposed tangs 20 of a flanged closure 22 to form a bayonet-like attachment or detachment construction as is conventional in radiator caps. A rivet 24 retains a hollow valve cage 26 with a spring disk 28 interposed with respect to the closure 22. The peripheral margin of the spring disk 28 is adapted to seat on an annular surface 30 at the top of the neck 12. The side of the neck 12 at the enlarged portion 14 above the shoulder 16 is fitted with an overflow tube 32 as is con- 3,388,825 Patented June 18, 1968 ventional. The cage 26 bears at least one opening 34 giving a generally radial communication between the interior of the cage 26 and the annular zone 35 around that cage and within the enlarged portion 14 of the neck 12. The bottom of the peripheral margin of the cage 26 is reversely crimped as at 36 tightly to retain on the cage an annular plate 38 and a flange 40 of a filter retainer or cage 42. The annular plate 38 is centrally apertured as at 44 and bears a seat 46. A vent valve arrangement is resiliently held by a coil spring 52 against the annular seat 46. A good seal at the seat or shoulder 46 is obtained by using a rubber sealing member 54 which is borne by a disk 56 interposed between the spring 52 and the rubber. Preferably, a vacuum relief valve 58 is employed and in the present instance it is conveniently, but not necessarily, made integral with the rubber member 54 in the form of a squeegee directed downwardly through the aperture 44.
An annular filter element 60 is retained by the cage 42. One end of the filter element 60 consists of an annular plate 62 held in sealed relation with the plate 38 by means of an interposed sealing washer 64. The other end of the filter element 60 includes a circular plate 65 nested on a conforming bottom 66 of the cage 42. The latter bears openings 68 in its cylindrical wall and the cage is of such diameter as to be clear of the inner wall of the neck 12 to present a clearance space 70 when the cap is in position on the neck.
Insofar as the present invention is concerned, the filter material of the filter element 60 may be of any suitable material of suflicient porosity and fineness to retain any impurities which may tend to immerge from the radiator tank when the central aperture 44 is open as will further appear.
When the cap is applied to the radiator neck 14 by rotary and cam action and engagement of the tangs 20 with respect to the flange 13 as is conventional, the disk 28 resiliently seats and a gasket 72 on the cap seats on the shoulder 16. -In FIGURE 1, the gasket 72 is made a part of the cap by using adhesive to hold the gasket in the flange 40. When under normal use of the cap, the main closure valve is closed on the seat 16 and the vent through the central opening 44 and to the overflow pipe 32 is closed by the valve arangement 50. If an excess pressure is developed in the radiator, it will be seen that such pressure will be dissipated by vapor, air or liquid passing radially and inwardly from the space 70 and through the filter material of the element 60 to lift the vent valve arrangement 50 against the spring 52 and cause a discharge from the overflow pipe 32. No dirt will interrupt a subsequent seating of the valve arrangement 54 or the shoulder 46 because of the protective function of the filter element 60. In the event an undue vacuum should occur in the radiator, the relief valve 58 becomes effective to admit air downwardly and through the filter. This inflow of air is not likely to cause any dirt to enter so the filter protection is not essential. For outflow, however, the filter 60 exerts its protection influence as stated above. The squeegee type of relief valve 58 is merely one type of valve which could be used for relieving vacuum but it too is protected by the filter element from any dirt which could arise from the radiator.
1. A radiator cap comprising a flanged closure at one end, said flanged closure being attachable to a radiator filler neck having an inner annular shoulder, the other end of said cap bearing an annular main closure valve adapted to seat on said annular shoulder, a vent passage extending through said other end of said cap and radially outward between said ends, and a filter element at said other end traversing said vent passage.
2. A radiator cap such as set forth in claim 1, and a vacuum relief valve carried by said annular main closure valve.
3. A radiator cap such as set forth in claim 1, said filter element being annular with an impermeable end remote from said main closure valve.
4. A radiator cap such as set forth in claim 1, said filter element being attached to said main closure valve and being of less diameter than the latter.
5. A radiator cap such as set forth in claim 1, a spring biased vent valve arrangement supported on said main closure valve and being adapted to control said vent passage, said vent valve arrangement being adapted to move in one direction to relieve pressure, and a vacuum relief valve supported on said vent valve arrangement and adapted to open to flow in the other direction.
6. A radiator cap as set forth in claim 1, a hollow valve cage depending from said flanged closure and bearing said annular main closure valve, a spring seated vent valve 4 arrangement housed in said cage to control said vent passage and movable with respect to said cage for pressure relief.
7. A radiator cap such as set forth in claim 1, a hollow valve cage depending from said flanged closure and bearing said annular main closure valve, a spring seated vent valve arrangement housed in said cage and controlling said vent passage, a vacuum relief valve also housed Within said cage and operable independent of said vent valve, and said filter element being positioned to shield said vent pas sage against outflowing dirt particles.
References Cited UNITED STATES PATENTS JAMES B. ."MARBERT, Primary Examiner.