US2534003A - Fillercap mechanism - Google Patents

Description

Dec. 12,

1950 M. M. CULVER ETAL FILLER CAP MECHANISM Filed Dec. 50, 1944 L I jg) "mu-q Patented Dec. 12, 1950 UNITED STATES FILLER-CAP MECHANISM Merlyn M. Culver and Lyle L. Duncan, Dayton, Ohio 3 Claims. 1

This invention relates to a readily removable covering or closure device such as the filler cap for use with liquid cooling systems for internal combustion engines, such as liquid cooled airplane engines, and more particularly for such cooling systems which are of the closed type in which substantial pressure is normally present in the cooling system during operation.

One of the principal objects of the invention is to provide a closure mechanism constructed for use with the cooling liquid supply inlet of such a system, which will seal the system effectively over the range of pressures existing during periods of operation as well as during standby or non-operating periods but which may be readily and easily actuated to permit access to the cooling system when desired.

Another object of the invention is to provide a filler cap or cover member construction which will automatically seal adequately at very low pressures, even negative pressures, and in which the efiectiveness of sealing will vary or increase with variations or increases in pressure in the cooling system, so that operatively tight sealing may be readily eifected throughout a wide operating range in a given engine and cooling system, or different ranges in differing cooling systems and different devices with which such systems are used.

Another object of the invention is to provide the filling opening of such a system with an inner closure member which is urged toward sealing position by spring pressure means adequate to effect sealing under non-operative pressures and which is also additionally urged toward sealing position by any pressure in the system resulting from the cooling medium so that the sealing elfect increases as the system pressure increases, and also to provide a readily removable outer member covering over the inlet opening to the cooling system and having detachable connection with the first said member and in which the second member is not subject to such pressures as may be exerted against the first member and which may thus be readily removed.

Other objects and advantages will be apparent from the following description and claims and the drawing.

In the drawing, which illustrates a preferred embodiment of the invention, and in which like characters of reference designate like parts throughout the several views thereof- Fig. 1 is a vertical sectional view, along the line l-I of Fig. 3, through the inlet into such a pressure cooling system for an engine showing the closure mechanism in place and in closed position;

Fig. 2 is a vertical sectional view at right angles to the plane of Fig. 1, along the line 2-2 of Fig. 1;

Fig. 3 is an inverted plan view of the closure mechanism;

Fig. 4 is a top plan view partly broken away of the closure mechanism;

Fig. 5 is an inverted section of the closure mechanism taken on the line 5--5 of Fig. 1 looking in the direction of the arrows but omitting the filling inlet or threaded neck; and

Fig. 6 is an enlarged fragmentary section showing certain details of construction.

The modern liquid cooled airplane engines, and some automobile engines, use closed cooling systems which are provided with a cover or closure member, ordinarily referred to as a filler cap, for the inlet through which the cooling medium is introduced. In modern high-powered liquid cooled airplane engines, which operate under extraordinary conditions of heavy load, quite substantial pressures will be built up during operation, at times as high as 50 pounds per square inch against the filler cap. In usual practice the filler cap in such engines has been a form of threaded closure plug, adapted to be screwed into threaded engagement with either internal or external threads on a flange or pipe surrounding the filling opening to be sealed tightly against such hi h pressures by means of a gasket or machined fit metal surfaces brought into sealing contact by screwing the closure plug or cap sufficiently tight down against the filler flange or pipe of the system. In some instances where small pressures are encountered the filler cap has been held in position by means of a bayonet slot connection; but where high pressures and the necessity for absolute certainty in sealing the liquid cooling system exists, as in liquid cooled airplane engines, it has been the universal practice to have filling plugs which could be screwed down tightly enough to make an effective seal against leakage even at the high pressures referred to. Such filler caps for high pressure cooling systems have had as very serious ebjections, first that to secure the pressures necessary for effecting the tight seal requires the use of wrenches or special tools, and when the caps are to be removed not only similar wrenches or special tools must be used but the frictional resistance or binding may be so great, especially in liquid cooled airplane engines, that hammers or other tools may be required to remove them,

and as a result they are frequently ruined or so damaged that they have a very short life and require constant replacement. In engines for fighter airplanes and the like it is well known that during the course of combat they may have to return to base for refueling and rechecking and to pick up additional ammunition and that the time element is extremely important. Under such circumstances the pressure in the cooling system is apt to be quite high and the time element does not permit of the plane remaining on the ground long enough to allow it to cool off. And with the parts expanded due to heat there is sometimes a tendency to distortion and binding so that the large frictional forces necessary for adequate sealin with the usual type of filler cap are at times greatly increased; When the time element is especially important this brings about the use of hammers or other tools referred to and frequently leads to such destruction of the filler cap that in a short time it becomes no longer sufliciently effective for sealing or is so battered up that it cannot be properly sealed or removed. Conditions .such as that would be especially true in very hot climates, in desert warfare, and in places like the South Pacific where planes may have to land and take 01? with great rapidity without the necessary tools and equipment being present. And even where the tools are available, frequently they may not be readily at hand and the same results may ensue. And, of course, the necessity for having special tools or of having the formerly usedcaps badly battered up is very objectionable because of the necessity for transporting replacement parts all over the world and having them available at all times. Secondly, as is well known the cooling fluid even at low pressures can develop vapors or steam of very high temperature, and when the cap is removed there is great likelihood of the operator or mechanic being severely injured or burned. With high pressure fluid systems there is still the third danger that even if the temperature is not high enough to cause burns the pressure may be so great that as the cap is released from the threads it may be blown away with great force, lacerating or breaking the mechanic hands, or causing severe injury to the mechanic or someone standing nearby. V

The present invention provides a closure construction which is completely adequate for effective sealing of these pressure cooling systems, under any pressures of use, which utilizes the internal pressure to supplement the sealing effected by the structure itself, and which is so constructed that opening and closing of the filling opening may be effected without the necessity of unscrewing parts tightly held together, as described above, thus leaving all of the necessary parts so that they may be readily placed in position or removed by mere hand manipulation and without the difiiculties and dangers above referred to.

The drawing illustrates a preferred embodiment of the invention which has been found very satisfactory for use with liquid cooled airplane engines such as those which power the so-called P38, P40 and P- 5l pursuit planes, which will withstand the highest pressures encountered in the cooling systems of suchv engines, and which nevertheless is very simple and readily operated and is entirely free from the objections referred to above.

4 ,y In the drawing a small portion of the cooling system of such an engine is shown and designated by the numeral It, the filling pipe or flange which surrounds the inlet opening being designated by the numeral II. The entire engine and liquid cooling system and other parts thereof are thought unnecessary to illustrate. As illustrated the part I I is interiorly screw threaded as shown at 2, to receive a closure member, the main body of 'WhiCh'ls designated generally by the numeral 26 and has an externally screw threaded annulus 26 which is mounted in the screw threads I2 of the filling pipe. This closure member is provided with a hexagonal rim 22 whose outer faces serve as seats for a wrench. An annular gasket723 is mounted about the annulus 2i and against the under face of the hexagonal rim 22 so that when the closure member '20 is screwed down tightly against the gasket, a tight seal is provided which prevents the escape of any vapors or steam through this threaded joint. Immediately adjacent the lower face 24, a groove is formed, as by machining, to provide a seat to hold the gasket '23 in place above the threads, and'so that it will not be dislodged or lost from the closure member during transportation or when being inserted into the inlet opening in'place 0f the regularly used filler cap, or removed for any purpose. The closure is provided with an opening 25 through which the radiator may be filled. Close to the edge of this opening there is cut a groove 27 (Fig. 6) which is undercut on the side away from the opening as shown at 28. Into this groove is placed an annular gasket 29 andthe lower edge '30 of the filling opening is peened upon and holds the gasket firmly in place.

In order to form a positive and effective sealing mechanism for this opening, and one in which the sealing effectiveness increases proportionately with any increases in pressure in the operating rangeof the engine coolingsystem and which is so constructed that ready access may be had to the cooling systeminlet without the use of special tools or damage to the sealing mechanism, the cooling mechanism comprises a movable sealing member, shown as a flap valve 3! which is providedwith a strengthening rib 32 and is pivotally mounted by arms 33, ion the pintle -35, which latter in turn is mounted in the body of the closure mechanism through holes 35 provided in the annulus for that purpose. The top surface of the flap 3| makes contact with the gasket 29, around the -opening 25, -under the thrust of springs '49 which are coiled about the pintle 3.5,are braced at one end against the bottom face of the flap 3! and at the other end against the annulus Z-lof the closure, the construction being such, that the springs are under tension and thus urge the flap 31 into sealing contact against the gasket 29. These springs may satisfactorilybe so constructed as to apply about three pounds per square inch pressure against the gasket29, a pressure which of itself has been found in practical useand under test adequate to insure sealing of-the systems ofsuch airplane engines at ordinary standby pressures, or even vatsomewhat reduced pressures, effective in the cooling system against the sealing mechanism. When pressures against the sealing mechanism increase they bear against :the fiap 3i and thus progressively increase the effectiveness .of the seal. As the pressures increase the summation of the springpressure plus that made effective by the cooling fluid maintain sealing effectiveness which varies or increases in step with variations or increases in the pressures tending to escape.

Mounted on the top of member 3| are oppositely extending flat arms, or detent lugs, formed integral with the upstanding portion 43 which in turn is integral with the main portion of the member 3|. These lugs or extensions Al, 42 are spaced from the top of the main body of member 3| and thus serve to receive beneath them portions of the outer cover 55 whereby the cover is impositively locked in place and the urge of the springs it! is supplemented.

The outer cover need not be as strongly constructed or of as satisfactory material as the sealing flap valve 3| and the adapter or closure member to which it is pivoted because the forces and pressures to which it is subjected are comparatively light. As will be seen so long as the member 3| seals tightly against the gasket 29, none of the pressure inside the cooling system is exerted against this cover member 56. This cover member is shown as made of a metal stamping which is provided with an annular step or shoulder portion 52 and with an exterior flange 53 which is held within the beaded-over edge 56 of the top piece 55. This cover is attached to the closure member by a chain 52, so that it will not become lost in ordinary operations. In Fig. i the top member 55 is broken away to disclose the inside of the member 5| and its relation with respect to the lugs or arms 4 i 42.

As shown in Fig. 4 the metal stamping 5| has an annular, extended portion 56 of dimensions such as to extend down into the opening 25 and which has an end closure having an elongated opening 55' which can be aligned with and is of such dimensions that it can be passed down over the cross arms or lugs 4|, 42. By positioning the coverso that the elongated opening 55 will pass down and receive the arms 4|, 42 the cover may then be given an angular turn of approximately 90 which will place the opening 55 crosswise of the lugs M, 52 as shown in the figures, the surrounding portion of the end closure thus moving between the arms ll, 42 and top of the main portion of the member 3|. The metal at the diagonal corners 5T, 59 of the elongated opening 55' is depressed to form two cam-like engaging faces for the adjacent bottom faces of the corresponding ends of the arms or lugs 4|, 52 so that as the outer member 55 is turned the lugs will ride up smoothly onto and into correct position on the end closure of member 5|.

By proper proportioning of the member 5|, the part 52 may rest against the top of the member and the spring of the end extension of member 5! may cause sufficient frictional resistance, as between the several contacting surfaces, to hold the outer cover against accidental displacement and also to give an upward lift to 3| to supplement the urge of the springs 40.

Preferably, however, the alternative and additional means shown may be provided. In this construction passages 5| are drilled or otherwise formed in the closure which house spring pressed balls 53, 64, respectively. Cooperating dents 65, 55 are made in the step part 52 of the closure member 55. This construction serves not only as an impositive lock to hold the outer member in position against accidental turning, but also serves to inform the mechanic who replaces the member 55 when the locking pieces are in correct relationship. The pressure of the springs 6 can be changed to apply greater Or less supplemental pressure to the member 50, to supplement the pressure of the springs 40.

The closure may be installed as a part of the original equipment of the cooling system or as a replacement. When it is desired to fill the cooling system the top cover 50 can be removed by hand without the use of a wrench, since it is subjected to substantially no pressure other than the frictional resistance referred to, and is free from the pressure in the cooling system because of the sealing action of the member 3|. When this is done the flap closure 3| will remain closed and sealed without danger of burning or injuring the mechanic. If the cooling fluid is cool the mechanic thrusts the spout of the filling hose against the top of the cross arms of closure means 3|, which opens with comparative ease, to permit adding cooling liquid to the system. These arms 4|, 42 are so extended that the filling spout will not strike against or damage the top surface of 3| which seats against the gasket 29, and thus effective sealing is insured. If the cooling fluid is hot and the pressures within the system are great, the mechanic can stand at a distance and depress the member 3| by means of a tool, until excessive pressures have been relieved and without any danger of injury. Generally such airplane engines are not supposed to be opened when hot; but sometimes, as in the emergency of combat conditions sufficient time is not available to permit cooling. For such emergency conditions the cooling system may be provided with a safety or pressure release valve 10 shown diagrammatically, which may be operated by the mechanic to reduce the pressures therein before operating of the closure is attempted. And also even with very high pressures extra tools or equipment is not necessary to open the closure member 3|, as the spout of the hose or container for the cooling liquid will ordinarily exert adequate pressure to effect opening, without any danger or injury to the operator.

The present invention provides also that dirt, sand which is ever present in desert warfare, and other extraneous materials are excluded, so that the closure would not be gummed or clogged up and will be ready for satisfactory and easy use under adverse conditions of weather, etc., and under the most rigorous conditions of service. The outer cover is held against being dislodged accidentally or by carelessness on the part of the workmen, by means of the spring pressed detent balls or by frictional resistance and yet may be readily opened for refilling without any special tools, and long life and certainty of operation are secured. It should be noted that the action of the detent balls tends to swing the closure member 3| about its pivot 35 due to the resilient frictional portions of the end of the extension 56; but internal pressure upon the closure member 3| as it increases tends to swing that member upwardly slightly as the sealing gasket 29 is compressed, and thus tight sealing closure is secured without any undue frictional resistance being placed upon turning movement of the outer cover 50. The frictional resistance, or spring detent balls, hold the outer cover against being dislodged accidentally or by carelessness on the part of the workmen.

The spring detent balls act as an impositive stop to indicate the position to which the outer cover should be turned. If for any reason, however, the mechanic turns the Outer cover to overrun the detent balls, the upwardly extending members 586il serve as stops against which the extensions 41-42 will strike so that there is a definite and positive limit to the turning member, so located that the outer cover will be held tightly in place, and if it tends accidentally to turn in the opposite direction such turning movement Will be automatically stopped when it reaches the spring pressed detent balls. The construction thus is essentially'simple and yet quite effective over a wide range of pressures in the cooling system, and does not require close machining or complex replacement parts. Also the closure will remain effective even though the outer cover is lost or destroyed and the closure will maintain its seal even at low pressures.

While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise formof apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

1. A closure for cooling systems for engines in which a liquid cooling system is operable at considerable internal pressure, and having an inlet opening into such system, comprising a closure mechanism therefor having an opening, means to mount a gasket about said closure opening, means to close one side of the closure opening comprising a pivotally mounted spring pressed member, oppositely extending arms carried by said spring pressed member extending into said opening, said spring pressed member having a sealing face for cooperation withthe gasket, means to close the other side of the clo-"' sure opening comprising a member having a portion overlapping the edge of said opening and another portion having an elongated slot alignable Withsaid oppositely extending arms to receive said arms, means to hold the slotted member in a selected position, and means to mount the closure member in the opening of the cooling system with the pivotally mounted spring pressed member normally urged to normal position and displaceable toward the interior of said cooling system for introducing fluid to the system.

2. A closure mechanism for a cooling system for liquid cooled engines having an inlet opening therein, a closure therefor having means for attachment to said inlet, an opening in the 010- sure mechanism, means to mount a gasket about said closure opening comprising an undercut groove having an inclined side wall for holding the sealing gasket therein, means to close one side of the closure opening comprising a pivotally mounted spring pressed member, oppositely extending arms carried by said spring pressed mem-v ber and extending into said opening, said spring pressed member having a sealing race for cooperation with the gasket, means to close the other side of said closure opening comprising a member having a portion overlapping the edge surroundingsaid opening and another portion having a locking slot alignable with said arms, engaging means and stops for said arms being formed ateach edge of said locking slot, means to hold the slotted member in a selected position with respect to said arms comprising a spring pressed detent, and means to attach the closure mechanism in sealing relation to the inlet opening of the system with the pivotally mounted spring pressed members normally urged toward closed position and displaceable toward the interior of the system for introducing fluid thereinto.

3. A closure for cooling systems for engines in which a liquid cooling system is operable at considerable internal pressure, and having an inlet opening into such system, comprising a closure mechanism therefor having an opening, means to mount a gasket about said closure opening, means to close one side of the closure opening comprising a pivotally mounted spring pressed member, oppositely extending arms carried by said spring pressed member extending into said opening, said spring pressed member having a sealing face for cooperation with the gasket, said arms extending oppositely across said sprin pressed member to terminate adjacent the gasket contacting portion thereof to prevent the filler spout from striking and damaging said gasket contacting portion, means to close the other side of the closure opening comprising a member having a portion overlapping the edge of said opening and another portion having an elongated slot alignable with said oppositely extending arms to receive said arms, means to, hold the slotted member in a selected position, and means to mount the closure member in the opening of the cooling system with the pivotally mounted spring pressed member normally urged to normal position and displaceable toward the interior of said cooling system for introducing fluid to the system.

MERLYN M. CULVER. LYLE L. DUNCAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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