US3917163A

US3917163A - Waterline thermostat and assembly

Info

Publication number: US3917163A
Application number: US321101A
Authority: US
Inventors: Frank E Obermaier; Arthur A Scott
Original assignee: Eaton Corp
Current assignee: Eaton Corp
Priority date: 1973-01-04
Filing date: 1973-01-04
Publication date: 1975-11-04
Anticipated expiration: 1992-11-04
Also published as: DE2400003A1; BR7400031D0; AU6382173A; FR2324204A7; USB321101I5; JPS49124621A; ES421978A1

Abstract

An improved thermostat and mounting assembly therefor wherein the power member of the thermal power unit is received within an especially configured stirrup which provides a streamlined flow pattern over and immediately upstream of the stirrup. The flow pattern established prolongs the life of the thermostat by reducing stirrup erosion while also improving the flow characteristics of the thermostat. In accordance with another feature of the invention safe assembly of the thermostat within the flow conduit is assured by an especially configured transverse wall piece of the thermostat locking into an interference fit with an especially configured outlet casting in the flow conduit.

Description

United States Patent Obermaier et al. 5] Nov. 4, 1975 WATERLINE THERMOSTAT AND 3,173,609 3/1965 Obermaier 236/34 ASSEMBLY 3,448,921 6/1965 Kelly 11 236/34 [75] Inventors: Frank E. Obermaier Lombard Prim,

ry Examzner-Edward G. Favors Arthur A. Scott, Mount Prospect, both of m Attorney, Agent, or Fzrm Teagno & Toddy [73] Assignee: Eaton Corporation, Cleveland, Ohio ABSTRACT [22] Filed: Jam 4, 1973 An improved thermostat and mounting assembly therefor wherein the power member of the thermal PP N05 321,101 power unit is received within an especially configured [44] published under the Trial Voluntary Protest stirrup which provides a streamlined flow pattern over Program on January 28 1975 as document no and immediately upstream of the stirrup. The flow B 321,101 pattern established prolongs the life of the thermostat by reducing stirrup erosion while also improving the 521 US. c1 236/34; 236/100 characteristics of the thermostat [51] Int. Cl. F01P 7/16 In accordance with another feature of the invention [58] Field of Search.... 137/219, 220; 236/34, 34.5, safe assembly of the thermostat within the flow 236/100 conduit is assured by an especially configured transverse wall piece of the thermostat locking into an [56] References Cited interference fit with an especially configured outlet UNITED STATES PATENTS casting in the flow conduit.

l,936,650 11/1933 Wade 137/220 6 Claims, 4 Drawing Figures US. Patent Nov. 4, 1975 Sheet 1 of2 3,917,163

WATERLINE THERMOSTAT AND ASSEMBLY This invention relates to thermostats of the poppettype and more particularly to the construction of such thermostats which tend to increase the life, efficiency, and assembly thereof.

The invention is particularly applicable to a poppettype waterline thermostat which is disposed within the conduit of a cooling system of a vehicle to control the flow of fluid through the engine in response to the temperature of the fluid and will be described with particular reference thereto. However it will be appreciated that the principles of the invention may have broader application and may be employed in any type of valve assembled in a conduit for controlling unidirectional flow of fluid therethrough.

Thermostats of the type to which this invention relates generally comprise a transverse wall piece from which extends an annular mounting flange. A ported valve seat formed within the transverse wall piece receives a temperature sensitive power unit which extends therethrough. The power unit has a relatively movable portion or casing connected to a valve which cooperates with the valve seat to open or close the flow of fluid through the conduit. A guide base wall portion appending from one end of the transverse wall piece guides the casing during its movement while also functioning as a spring seat for a spring which biases the valve into seating engagement with the valve seat. Extending upwardly on the other end of the transverse wall piece is a stirrup formed from an elongated narrow piece of stock bent along its longitudinal axis to provide a fixed stop for the end of a power member which extends from the casing of the thermal unit and abuts against the stirrup. Relative movement between the power member and casing causes the valve to move out of engagement with the valve seat permitting coolant flow to pass therethrough.

The coolant flow which is turbulent directly impinges against the stirrup to such an extent that stirrup failure results, rendering the thermostat inoperative. Thus the coolant employed in an engine is actually a slurry composed of core sand, anti-freeze, water and other foreign matter which directly impinges against the stirrup when the thermostat is opened and eventually erodes the stirrup to the extent that failure occurs. Attempts to correct this condition by increasing the cross-sectional thickness of the stirrup have proved unsatisfactory. Also, while satisfactory results have been achieved when employing a stirrup formed from wear-resistant material such as stainless steel, the cost of such thermosta ts'is generally considered prohibitive.

Furthermore when the thermostat is assembled into the flow conduit, it is initially placed in an opening in the water jacket which defines the downstream or high pressure portion of the conduit. The outlet casting which defines the upstream or low pressure portion of the flow conduit is then positioned over the top of the thermostat and bolted into the water jacket to secure the thermostats annular mounting flange therebetween. Because of the configuration of the outlet casting which is dictated by engine design and also the play ofthe thermostat in the water jacket opening, the thermostat is not infrequently rendered inoperative during positioning and bolting of the outlet casting as a result of distortion of the power member and the stirrup.

It is thus a principal object of the subject invention to provide a thermostat having an especially configured stirrup which resists erosion while also providing a thermostat mounting arrangement which permits the thermostat to be assembled in a flow conduit without damage thereto.

In accordance with the invention there is thus provided a thermostat comprising a transverse wall piece having formed therein a ported valve seat. Disposed within and extending from both ends of the transverse wall piece is a temperature sensitive power unit comprising a power member at one end and a casing portion at the other end. Secured to the casing portion is a valve member cooperating with the ported valve seat. Appended to one end of the transverse wall piece is a base wall portion which serves to guide the casing portion of the power unit while also housing a spring which biases the valve into a normally closed position. Extending from the other end of the transverse wall piece is a stirrup having a formed apex spaced from the center of the opening in the transverse wall piece to receive the tip of the power member. The stirrup is further defined as having at least two contiguous formed portions extending from the apex to the end of the transverse wall piece. The formed stirrup portions are characterized by having a substantially closed, crosssection profile which streamlines the coolant flow around the stirrup to prevent direct impingement thereagainst.

In accordance with another feature of the invention the transverse wall piece is further defined as having an annular flange at one of its ends and an upwardlyextending sleeve portion spaced radially-inwardly from and contiguous with the flange. The sleeve portion is generally circular and defined by a first predetermined minor diameter. At least one protrusion extends outwardly from the sleeve portion to define a second, major sleeve diameter. The outlet casting which receives a portion of the thermostat to define the upstream or low pressure side of the flow conduit has an elliptical base opening which contacts the thermostats sleeve portion. In particular the sleeve portion is fitted into the base opening of the outlet casting with major and minor diameters aligned respectively and twisted into an interference holding condition whereby the thermostats major diameter is aligned with the minor diameter of the base opening in the outlet casting.

It is thus an object of the present invention to provide a thermostat having an especially formed stirrup portion thereof which increases the operating life of the thermostat.

It is another object of the present invention to provide a thermostat having an especially formed stirrup portion thereof which streamlines the flow of fluid when the thermostat is opened to minimize the pressure drop in the upstream portion of the flow conduit.

It is another object of the invention to provide a thermostat assembly which permits the thermostat to be lockingly engaged with the upstream conduit portion to avoid damage to the thermostat during assembly of the upstream conduit portion with the downstream conduit portion.

The invention may take physical form in certain parts and arrangement of parts, a preferred embodiment of which will be described in detail herein and illustrated in the accompanying drawings which form a part hereof and wherein:

FIG. 1 is a sectional view of a thermostat mounted in a conduit and shown in an open position;

FIG. 2 is a top view of the thermostat in locking engagement with the upstream portion of the conduit with the upstream conduit shown partially in section;

FIG. 3 is a side elevation view in section of the thermostat taken along Line 3-3 of FIG. 2 and showing the thermostat in a closed position; and

FIG. 4 is a cross-sectional view of the stirrup portion of the thermostat taken along Line 44 of FIG. 3.

Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only and not for the purpose of limiting same, FIG. 1 illustrates a thermostat l disposed within a flow conduit 12 which includes an upstream or low pressure portion 12" defined by an outlet casting 14 and adownstream or high pressure portion 12, defined by the engine water jacket 16.

Thermostat comprises a transverse wall piece 18 having a top and bottom-

end

20 and 22 respectively from which extends an especially formed stirrup 24 and a base wall portion 26 respectively. More particularly the transverse wall piece 18 is defined by an annular flange 28 at its bottom end 22 leading into an especially formed cylindrical seating section 30 which in turn leads into a frusto-conical throat section or valve seating surface 32in turn leading directly into a cylindrical port wall 34.-

Disposed within and extending from both ends of the transverse wall piece'18 is-a' thermal sensitive power unit identified by the numeral 36. Power unit 36 includes a temperature sensing portion 38, an enlarged diameter collar 40 formed'about the upper end of the sensing portion 38, a guide section 42 and a power member or piston 44 which is slideable within the guide section 42 and extensible from the guide upon predetermined increases in ambient temperature sensed by the sensing portion 38.'Such thermal elements are well understood by those skilled in the art and the

parts

38, 40, 42 are commonly referred to as the casing 46.

The base wall portion'26 extending from the bottom end 22 of the transverse wall piece 18 includes a pair of legs 48 shown staked at one end to the transverse wall piece 18 and formed at their other ends into an upwardly and inwardly extending cylindrical guide 50; the guide 50 and legs 48xdefining a cylindrical recess 52 which functions as a seat for one end of a compression spring 54. The guide 50 is positioned in an embracing relation to the temperature sensing portion 38 of the power unit 36 and serves to guide the unit for rectilinear movement as the ambient temperature of the sensing portion varies.

The opposing end of compression spring 54 abuts against a movable valve member 56 which is defined by an inner annular outturned flange 58 permanently affixed to the guide section 42 of power unit 36 and an outer annular valving section 60 which compresses spring 54-. The annular valving section 60 is cooperable with the frusto-conical valve seating surface 32 to control the flow of coolant through the cylindrical port wall 34. I l

The stirrup 24 which is contiguous with and of the same material as the cylindrical port wall 34 constitutes an important part of the subject invention. Stirrup 24 comprises a pair of identically formed leg portions 62 extending upwardly and angularly inwardly from diametrically-opposed points on the cylindrical port what into the recess 72 of power member 44 to assure that the power member 44 will not move retractively; relative to the casting 46 and out of the apex 64.

The formed leg portions 62 shown in FIG. 4 are char- I acterized in that they possess a substantiallyclosed cross-section profile. This profile is defined by a straight outer surface 76 and side surfaces 78 appending from the lengthwise rounded edges80 of the outer surface 76. The side surfaces 78 taper downwardly and inwardly to contact each other at their free ends 82 along a plane (shown as centerline 84 in FIG. 4) which bisects the outer surface 76 i.e., at an angle X of 45 relative to the centerline 84 of the outer surface 76.

This configuration of the formed leg portions 62 assures that the turbulent coolant flow shown as arrows in FIG. 1 will be streamlined around and immediately upstream of the stirrup 24. Thus direct impingement of i the coolant against the stirrups outer surface 76 which results in erosion and premature failure of the stirrup is avoided. importantly test results have shown that the streamlined flow pattern resulting from the stirrup configuration produces a smaller pressure drop in the up stream portion of the conduit 12" than that which occurs in thermostats of identical construction not possessing the formed stirrup leg portions 62 of the present invention.

Referring now to FIG. 2 the seating section 30 of wall piece 18 is shown substantially circular having a nominal or minor diameter D-l. A pair of diametricallyopposed protrusions 88 extend from predetermined points on the periphery of seating section .30 to define a major diametrical distance D-2; the difference between D-1 and D-2 in the embodiment shown within a range of 0.025 inch to 0.035 inch. The outlet casting 14 has an elliptical opening 90 at the base thereof defined by a minor axis D-l' and a major axis D-2'; the

difference between D1 and D2' in the embodiment shown within a range of 0.035 inch 0.045 inch and importantly D-l of opening 90 being at least 0.015 inches smaller than the distance D-2 of the thermostat seating section 30.

The thermostat is initially placed in the outlet casting opening with thermostat minor and major diametrical distances D-1 and D-2 aligned with the minor and major axes D-1' and D-2 of the outlet casting opening 90 respectively. The thermostat 10 is then locked into place by twisting seating section 30 into an interference surfaces 96 tapering outwardly to form an apex 98.

Thus the cylindrical seating section 30 of the transverse wall piece 18 could be formed as an ellipse similar to that of the outlet casting 14 to accomplish the desired locking action. Additionally the locking engagement could be accomplished by designing the interference fit between the outlet casting l4 and the thermostat at any point on the transverse wall piece 18 which does not interfere with the upstream flow. Thus the protrusions 88 could be applied to the cylindrical port wall 34 of the transverse wall piece 18 if the outlet casting opening 90 be similarly modified.

The present invention has been described with reference to a preferred embodiment. Obviously additional modifications and alterations will occur to others upon reading and understanding of the specification. It is my intention to include all such modifications and alterations insofar as they come within the scope of the present invention.

It is thus the essence of the invention to provide an improved thermostat having an especially formed stirrup configuration to produce streamlined upstream coolant flow while also providing an especially formed wall piece section in combination within an especially formed outlet conduit to assure accurate positioning of the thermostat within the flow conduit.

Having thus defined my invention, we claim:

1. A thermostat assembly for controlling the flow of fluid through a conduit comprising:

a generally cylindrical transverse wall piece having first and second open ends and defining a valve seat surface therein; power unit within said wall piece, said power unit having a power member extending from said first end and a casing portion extending from said second end; valve member affixed to said casing for common movement therewith and cooperable with said valve seat to open and close the flow of fluid through said thermostat;

a base wall member affixed to said wall piece and extending from said second end, said wall piece having a guide opening for said casing and a spring support portion formed therein;

compression spring position between said valve member and said spring support portion and normally biasing said valve member in a closed position;

stirrup integral with and of the same material as said transverse wall piece, said stirrup having at least two formed leg portions having an outer surface and side surfaces appending from the lengthwise edges of said outer surface, said side surfaces tapering downwardly and inwardly to contact each other at their ends along a line which bisects said outer surface; and

means for securing said wall piece in said conduit.

2. A thermostat assembly as defined in claim 1 wherein said outer surfaces and said side surfaces of said formed portions are contiguous with said apex and said surfaces of said apex are crimped about said power member to secure said power member within said apex.

3. A thermostat assembly as defined in claim 1 wherein said wall piece comprises an annular flange at said second end, an upwardly-extending sleeve portion spaced radially-inwardly from and contiguous with said flange, said sleeve portion having a generally circular periphery of diameter having a first distance and at least one portion of said sleeve extending outwardly from said periphery to define a second diametrical distance, and an upstream portion of said conduit having a similar configuration as said sleeve portion for receiving said sleeve portion.

4. A thermostat assembly as defined in claim 3 wherein said upstream portion of said conduit has first and second diametrical distances similar to that of said sleeve portion and said sleeve portion is locked into engagement with said conduit portion by aligning said second diametrical distance of said sleeve portion with said first diametrical distance of said conduit portion.

5. A thermostat assembly for mounting a thermostat in a conduit to control the flow of fluid therein, the assembly comprising:

a thermostat having a transverse wall piece, a base wall member secured thereto to define an opening therebetween, and a power unit disposed in said opening, said wall piece having an annular flange and a sleeve portion spaced radially-inwardly of said flange and contiguous therewith, said sleeve portion extending perpendicular to said flange and having a generally circular periphery with at least one protrusion extending therefrom;

an outlet gasket defining the upstream portion of said conduit having an elliptical base opening receiving said sleeve portion in tight engagement therewith; and

fastening means for mounting said thermostat in said outlet gasket by compressing said flange in a sealing manner.

6. A thermostat assembly as defined in claim 5 wherein said elliptical openinghas a minor axis of distance greater than said diameter of said sleeve portion but less than the diametrical distance of said sleeve portion between said protrusion'whereby said thermostat is locked in predetermined position in said outlet castmg.

Claims

1. A thermostat assembly for controlling the flow of fluid through a conduit comprising: a generally cylindrical transverse wall piece having first and second open ends and defining a valve seat surface therein; a power unit within said wall piece, said power unit having a power member extending from said first end and a casing portion extending from said second end; a valve member affixed to said casing for common movement therewith and cooperable with said valve seat to open and close the flow of fluid through said thermostat; a base wall member affixed to said wall piece and extending from said second end, said wall piece having a guide opening for said casing and a spring support portion formed therein; a compression spring position between said valve member and said spring support portion and normally biasing said valve member in a closed position; a stirrup integral with and of the same material as said transverse wall piece, said stirrup having at least two formed leg portions having an outer surface and side surfaces appending from the lengthwise edges of said outer surface, said side surfaces tapering downwardly and inwardly to contact each other at their ends along a line which bisects said outer surface; and means for securing said wall piece in said conduit.

5. A thermostat assembly for mounting a thermostat in a conduit to control the flow of fluid therein, the assembly comprising: a thermostat having a transverse wall piece, a base wall member secured thereto to define an opening therebetween, and a power unit disposed in said opening, said wall piece having an annular flange and a sleeve portion spaced radially-inwardly of said flange and contiguous therewith, said sleeve portion extending perpendicular to said flange and having a generally circular periphery with at least one protrusion extending therefrom; an outlet gasket defining the upstream portion of said conduit having an elliptical base opening receiving said sleeve portion in tight engagement therewith; and fastening means for mounting said thermostat in said outlet gasket by compressing said flange in a sealing manner.

6. A thermostat assembly as defined in claim 5 wherein said elliptical opening has a minor axis of distance greater than said diameter of said sleeve portion but less than the diametrical distance of said sleeve portion between said protrusion whereby said thermostat is lockEd in predetermined position in said outlet casting.