US 3136292 A
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Description (OCR text may contain errors)
June 9, 1964 R. R. MITCHELL 3,136,292
RADIATOR CAP Filed May 24, 1962 INVENTOR. RAYMOND R. M/TGHELL United States Patent 3,136,292 RADIATOR CAP Raymond R. Mitchell, Lake County, Ind. (2304 E. 73rd St., Crown Point, Ind.) Filed May 24, 1962, Ser. No. 197,566 2 Claims. (Cl. 116114) a reduced section in the form of an annular seat against which the axially movable seal closure of the radiator cap is seated ,by a coil spring which encircles a center stem or a collar connecting the cap member and the seal closure. This center collar of the conventional radiator cap is connected to the cap member having interposed therebetween a freely rotatable diaphragm which serves as a base for confining the coil spring between the cap member and the axially movable seal closure and prevents relative angular movement between the ends of the spring while the cap is rotated relative to the seal closure. The axially extending flange of the cap member engages the camming edges of the spout to tighten the cap to the spout.
The coil spring holding the seal closure against the annular seat in the spout responds to a predetermined pressure ranging from approximatelylO p.s.i. to psi. above atmosphere so that when the vapor pressure in the radiator has increased due to the increase in temperature of the liquid coolant to a point which exceeds this predetermined pressure setting, the seal closure will be lifted from the annular seat to allow the excess pressure to escape to atmosphere.
The particular problem to which this invention is directed is the escape of coolant vapor, and the liquid coolant with the escaping vapor, from the radiator of an automobile when the radiatorcap is removed while the vapor'pressure in the radiator is greater than atmosphere. The radiator cap is removed regularly as part of the service routine rendered the automobile each time the automobile is stopped for refueling. Not only is some of the liquid in the radiator lost each time the radiator cap is removed during these service stops, but'also the removal of the capwhile under pressure is a serious safety hazard, particularly .sincethe high pressure seal closures.
common on the newer automobiles results in a higher operating temperature of the liquid coolant.
Accordingly, a principal object of my invention is to provide a radiator cap, the parts of which are. of such construction and arrangement that the liquid'coolant is automatically raised-from the radiator by the increased vapor pressure therein to a reservoirin the radiator capso that the liquid coolant may be observed and the radiator cap need not be removed while under pressure if it is not necessary.
Another object of my invention'is to-provide a radiator cap which has communicating passageways between the radiator and the reservoir included therein and alsov be scription and drawings which illustrate a preferred embodiment thereof, wherein:
FIGURE 1 is a sectional elevation of the radiator cap.
embodying my invention connecting the radiator spout including a fragmentary part of the radiator and showing the tubular passageway submerged in the liquid coolant to a preselected level,
FIGURE 2 is a sectional elevation of the present invenf tion showing the tubes above the liquid coolant level which occurs when the level has receded below the preselected level, and
FIGURE 3 is a plan elevation of the radiator ,cap of my invention.
Referring more particularly to the drawings, numeral 10 designates the conventional automobile radiator, shown in fragment, with which is associated a conventional filler spout 12 having interior thereof, at oneend, an annular seat 14; AXially-spaced from seat 14 and exterior of spout 12 at the other end thereof are provided inclined edges 16 and 18.. Overflow pipe 20 is conventionally provided to communicate the interior of the spout to atmosphere and is located between the annular seat 14 and the other end thereof.
My cap assembly, designated generally by the numeral 22, comprises a cap member 24 having an axially extending flange 26. The lower edge 28 of flange 26 has two or more inturned strips 30 adapted to engage the inclined edges 16 and 18 of spout 12 which, by rotational movement of the cap member 24, wedges the cap 22 against the spout 12. Cap member 24 has a central opening 32 which receives a cylindrical reservoir chamber 34. One end of reservoir member 34 is closed by a circular disc 38 having a peripheral portion overlapping the annular seat 14 interior of the spout 12. The peripheral portion of the disc 38 overlapping the annular seat 14 is provided with a seal diaphragm 40 so that seal contact may be made between disc 38 and annular seat 14. End 42 of reservoir chamber 34 passes through opening 32 of cap member 24 and is axially slidable to and fro therein. Helical or coil spring 44 surrounds reservoir chamber 34 and is confined between disc 38 at one end and cap member 24 at the other end. Spring 44 serves to urge disc member 38. away from cap member 24. When'the cap assembly 22 is mounted on spout 12 of radiator 10, spring 44 urges disc 38 including seal diaphragm 40 against annularseat 14 thereby providing a valved closure for the radiator. I also show abearing diaphragm 46 interposed between the cap member 24 and spring 44 on reservoir chamber 34-which is free to rotate relative to cap member 24. Bearing diaphragm 46 serves to frictionally engage the end of .spout 12 and provide a seat for spring 44 at one or" the ends thereof. Bearing diaphragm 46 remains stationary while cap member 24 rotates relative to spout 12. The opposite ends of spring 44 are thereby preventedv from engaging relative rotating confining seats which would, in eifect, wind or unwind the helix of spring 44 and affect the constancy of the spring pressure. Bearing diaphragm 46 also prevents the tendency ofseal diaphragm 40 to rotate-against the annular seat 14 which otherwise would cause. excessive wear of the seal diaphragm. The. bearing diaphragm feature, however, is well known inthe art and is not a part of the present invention.
The other end 42 of cylindrical reservoir chamber 34 extendingthrough opening 32 in cap member 24 -is provided with threads or any other suitable means for fastening thereto a transparent cover 50. I provide transparent cover 50 mounted on end 42 of reservoir chamber 34 with a seal 52 therebetween and held tight thereto by means of a threaded ring 54. The threaded ring 54 will also serve to provide an abutment for cap member 24 Patented June 9, 1964.
3 which is urged outwardly by spring 44 and thereby also serves to fasten the parts of the present radiator cap 22 in assembled relation.
The reservoir member 34 is provided with a one-way valve 56 preferably adjacent the top end thereof. I show valve 56 as comprising a ball seated against a vent aperture by spring means in a housing which is clamped in an opening in a transparent cover 50.
Circular disc 38 has an aperture 58 fitted with a short tube 60 of preselected length. Tube 60 terminates in the reservoir chamber 34 adjacent the disc 38. The preselected length of tube 60 is sufficient to submerge the free end thereof in the liquid coolant when the coolant is at normal operating level in the radiator as shown in FIGURE 1. A second tube 62 is fixed to a second aperture 64 in disc 38 adjacent tube 60. End 66 of tube 62 extends into the reservoir chamber 34 above tube 60.
In operation, the radiator cap 22 embodying the present invention is fastened to the automobile radiator 10 in the customary manner. The free end of tubes 60 and 62 are submerged to a predetermined level in the liquid coolant below which the level of the liquid in the radiator is deemed low and will require replenishing. As the internal combustion engine warms up to operating temperature the vapor pressure in the radiator 10 increases due to the increase in temperature of the liquid coolant. This vapor pressure, as stated above, will increase to the limit imposed by spring 44 on seal closure disc 38. The interior of reservoir chamber 34 being valved as at 56 to atmosphere, a pressure differential will exist between the radiator 10 and the reservoir chamber. With tubes 60 and 62 providing passageways communicating reservoir chamber 34 and radiator 10, liquid coolant will pass through tubes 60 and 62 to fill the reservoir chamber 34. The atmosphere in chamber 34 will be compressed by the liquid coolant as it enters the reservoir chamber until the pres sure of the atmosphere therein counterbalances the vapor pressure in radiator 10 at which time the fiow of liquid from radiator 10 to reservoir chamber 34 through tubes 60 and 62 will stop. Therefore, as long as the pressure in radiator 10 is greater than atmosphere and the liquid coolant in radiator 10 is at normal level, that is above tubes 60 and 62, the liquid coolant will rise to the reservoir chamber 34 and be observable therein through transparent cover 50, and it will not be required to remove radiator cap 22 to observe whether there is sufiicient liquid coolant in the radiator. When the liquid level in the radiator 10 drops below the tubes 60 and 62 as shown in FIGURE 2, the liquid in the reservoir chamber 34 will drain into the radiator 10 through the tube 60. Any pressure differential between chamber 34 and radiator 10 Will have been equalized by tube 62 which serves to facilitate the drainage of liquid from reservoir chamber 34 to radiator 10. An empty reservoir chamber 34 when the radiator is heated to operating temperature will, of course, indicate that the liquid level in the radiator is below normal level and will require replenishing. Necessary precautions may then be taken when removing the radiator cap 22. An empty reservoir chamber when the radiator is cool such as when the automobile engine has not been running, does not indicate that the liquid coolant in the radiator is below the normal level since there is no pressure differential between the radiator 10 and the reservoir chamber 34 to cause the liquid in the radiator to rise to the reservoir chamber and any liquid in the reservoir chamber will have normally drained back into the radiator. However, under this condition, the radiator cap 22 may be removed without liquid coolant loss. Valve 56 is provided to allow air to enter reservoir chamber 34 when the pressure therein drops below atmosphere. This will occasionally occur due to the fact that some liquid coolant will be lost and upon condensation due to cooling the pressure in radiator 10 will drop below atmosphere since a larger volume is then available.
It is apparent from the above full and complete description that my invention constitutes a novel improvement over the prior art in that my invention prevents loss of liquid coolant by eliminating the unnecessary removal of the radiator cap to ascertain the coolant level in the radiator. Also, my improvement may be easily combined with the conventional radiator cap without radically changing the manufacturing method employed for the conventional radiator caps.
Though I have described a single preferred embodiment of my invention, it is realized that changes and modifications may be made in the device by those skilled in the art Without departing from the spirit of the invention. Therefore, what I claim as my invention is set out in the appended claims.
1. For a vehicle radiator and the like having a filler spout provided with an annular seat therein; a valve closure comprising, an annular cap member adapted for retaining engagement with said spout, a sleeve member axially slidable through said annular cap member, a closure for one end of said sleeve member, said closure comprising a resilient peripheral portion for seal contact with said annular seat of said spout, a tube communicating the interior of said sleeve member at said one end thereof extending longitudinally exterior of said sleeve member, a second tube extending longitudinally exterior of said sleeve member and extending longitudinally interior thereof communicating the interior of said sleeve member forward of said first tube at said one end of said sleeve member, a closure for the other end of said reservoir, said second closure being transparent and having valve means communicating the exterior of said sleeve member and the interior thereof, and spring means seated on said cap member for holding said first mentioned closure of said sleeve member in seal contact with said annular seat.
2. For a vehicle radiator and the like having a filler spout provided with an annular seat therein; a cap comprising, a ring member adapted for retaining engagement with said spout, a reservoir member axially slidable through said ring member, a closure for one end of said reservoir member, said closure comprising a resilient peripheral portion for seal contact with said annular seat of said spout, a tube communicating the interior of said reservoir member at said one end thereof and extending longitudinally exterior of said reservoir member, a second tube of reduced dimension in said first mentioned tube extending longitudinally interior of said reservoir member communicating the interior thereof forward of said first tube at said one end of said reservoir member, a closure for the other end of said reservoir member, said second closure being transparent, means for connecting said second closure to said tubular member, said connecting means providing an abutment for said ring member, and resilient means confined between said ring member and said first mentioned closure for urging said first mentioned closure away from said ring member.
Swank July 2, 1935 Danias June 24, 1958