US2228198A - Double acting thermostatic mechanism - Google Patents

Description

Jan. 7, 1941. J CERNY 2,228,198

DOUBLE ACTING THERMOSTATIC MECHANISM Filed Dec 22, 1937 INVENTOR JOSEPH A. CERNY BY ATTORNEYJ Patented Jan. 7, 1941 nounne some memos'rs'rrc MECHANISM Joseph A. Oerny, Cleveland,.0hio, assignor to The Titan Valve and Manufacturing Company, Cleveland, Ohio, a corporation of Ohio Application December 22, 1937, Serial No. 181,115 1 '2 Claims.

This invention relates to improvements in thermostatic control mechanism and, more particularly, to a control wherein a single thermostatic element actuates a plurality of control 5 members.

One of the objects of the present invention is-to provide mechanism for actuating two or 2 more control members from a single thermostatic means and a particular application oi. this control mechanism is the-opening of-two valves successively during movement of the thermostaticelement in-one direction.

A particular feature hfthepresent invention is the-opening of a limited capacity or'pilot valve toa fuel burner upon demandof .the thermostatic element followed by=tliefopening of a large capacity or main valve after a time interval under 'theicontrol of vthe thermostatic element.

Other featuresof .thepresent invention have to do with the specific arrangement as the parts whereby a small number ois parts" simply arranged bring about the results set forth. These features-will be better undrstoodfrom the ac companying specification and drawing and the essential ieatures will be summarized in the claims.

In the drawing, Fig. l is acentral longitudinal section through a device embodying my inventionshowing the parts with both valves closed; Fig. 2 is a partial view of the mechanism shown in Fig. 1 showing the parts with one of the valves open; Fig. 3 is a similar view showing the parts with both valves open; Fig. 4 is a partial transverse sectional view taken along the line 4-4 of Fig. 2; while Figs.-5 and 6 are side elevations of the levers shown in Figs.- 1 to 3.

Certain features of my invention are applicable,.where the thermostatic device actuates a plurality of control members whether these members be switches, valves or any other suitable device for controlling adeslred operation. I have illustrated my invention as applied to the actuation of two fluid controlled valves having fluid inlet ports I i and I2 and an outlet.

port It. Valves ll and li control the ports II and I2 respectively and are normally spring pressed to closed position.

the fluid supply conduit enters the casing ill at Reierring to Fig. 4

I5 and beyond this point the fluid s m-rm oFFlce 1 stream is divided by partition Illa providing an upper fluid inlet chamber l6 and a lower'-iluid inlet chamber H. The fluid supply to chamber i6 is by way .of a restricted portl8 and the supply to chamber I1 is by way of the large port it. Pref-w F erably, adjusting screws 20 and 2| are provided for controlling the flow through ports l8 and i8, respectively, and sealing screws 22 cover the ad- Justing screws; I have hereinafter referred to .II as a minor inlet port and I2 as a major inlet portion and to valve II as a minor valve II as a major valve.

valve and to By these terms I mean to imply that port II and valve l4 supply a small amount of gas while port i2 and valve lb supply the main or large supply of gas.

This

language is used to cover any structure by which this is accomplished because obviously it may be attained either by valve design or by restriction of passageways as in the present embodiment.

.One of the applications v or a structure of the general nature here shown is in water heaters or the like where a burner suppliesjheatto the water reservoir and the burner is housed in a Q6 combustion chamber which with its flue connections is unable to carry oil. the products of combustion when the parts are cold. In such an installation a conduit connects the fluid outlet I3 with the burner of the water reservoir and a thermostatic element 23 is located reservoir. In such a system; when in the water the thermostat 23' demands heat, my improved device is 7 arranged to'flrst open valve it toi supply a limited amount of fuel to the burner so as to :3

heat up the parts, after which the thermostatic known type comprising a tube'fla' having relatively large coemcient of expansion and arcd 23b of material having a relatively small coefli- .cient' of expansion. These two are fastened together at 234: so that when the tube is cold and contracts, the rod 22!; is movedtoward the left;

and when the tube is heated and expands, the

rod moves to the right as viewed in the various drawings.

The left end of red 2312 enters the 50 casing I0 through an opening which is sealed at 28. The deviceat 25 is a well known arrange-- ment for adJustlng the temperature range of the.

thermostatic element. I Mounted within the casing is are a main lever 5| 2! and a snap lever 21 fulcrumed on the casing at 20 and 29, respectively. This places the levers alongside each other with the free end of each lever extending toward the fulcrum of the other. In the device shown the fulcrums are open-knife edges abutting suitably formed projections on the casing. A tension spring 30 is connected between the free ends of the levers. The thermostatic element engages lever 26 at 3| and the arrangement of the parts is such that upon heating and cooling of the thermostatic element, lever 26 oscillates so as to carry the end "a of spring 30 back and forth to opposite sides of fulcrum 2!. Thus the tendency of spring 38 in the position of Fig. 1 is to hold lever 21 toward the right and in the position of Figs, 2 and 3, the same spring moves lever 21 toward the left or counterclockwise. The effect of spring 3! obviously is to hold both levers in position against their fulcrums and to hold lever 26 against rod 23b.

The valve lifis provided with an extending portion Ila calculated to open valve l5 at the proper time as will later appear.

ll The construction of levers 28 and 21 will bet- Jl'and is bifurcated at its lower end providing a pair-o1 knife edges 2") to coact with the fulcrum 2!. The central opening of lever 2'! permits the operation of lever 26 and spring 30.

The operation of the device is as follows: With the parts in the position of Fig. 1, it will be understood that the thermostat 23 is satisfied,

that is, thewater in the hot water reservoir of the heater has arrived at a predetermined temperature and all fuel to the burner is shut 01!. Upon the'cooling of thermostat 23, rod 231) movestoward the left, carrying lever in a clockwise direction about, fulcrum 28 until the point 28a passes to the left of fulcrum it carrying the axis of spring 30 to the opposite side of the fulcrum, whereupon lever 2'! moves counterclockwise with a snap action opening valve II as shown in Fig. 2. Fuel is then supplied to the burner through the restricted opening it, thus heating up the combustion chamber and hue. The heat-thus supplied to the water reservoir is insufficient to change the action of thermostat 23 which continues to contract, carrying valve ll supplying more and more fuel to the burner of the water heater until the thermostat 23 is satisfied sumciently to reverse the movement of rod 231). Thereupon the heating of the thermostat causes 23! to return toward the right which will cause a. gradual closing of valve until it is fully closed, after which the lever 28 will return to the position of Fig. l, causing arca es a clockwise movement of snap lever 21 and permitting valve M to close with a snap action due to its biasing spring.

It will be noted that the lever arm of lever 26 eifective to actuate valve I5 is approximately ten' times the lever arm between fulcrum 28 and point II where the thermostat engages the lever- This gives a considerable multiplication of the i slowly so as to progressively build up the flame at the burner until the action of the themestat is reversed, after which the main supply of fuel is gradually cut off from the burner and as the thermostat reaches its limiting or satisiied position the last increment of fuel is cut oil with a snap action.

- What I claim is:

1. Control valve mechanism of the class de-- scribed, comprising a casing having a chamber provided with major and minor fuel inlet openings and an outlet, a valve controlling each,

opening, main and snap action levers fulcrumed in said chamber and lying alongside each other with the free end of each extending toward the fulcrum of the other, a spring connecting said levers, a thermostatic element directly engaging said main lever, said main lever being adapted to engage and operate said major valve with graduating effect, and said snap action lever being adapted to engage and suddenly operate said minor valve, said mainlever being arranged upon heat demand of said thermostatic element to move its spring connection past said snap action lever fulcrum to a minor valve operating position before said main leve'r engages said major valve.

2. Control valve mechanism of the class described, comprising a casing having a chamber provided with major and minor fuel inlet openings and an outlet, major and minor-valves respectively controlling said openings, a main lever fulcrumed in said chamber and adapted to engage and operate said major valve, a thermo static element directly engaging said main lever, a snap action lever adapted to engage and operate said minor valve, a spring having one end carried by said snap action lever, said snap 8C- tion lever having a fulcrum point and having its free end extending toward said main 'leverfulcrum, said spring having a connection point at its other .end, one of said points being fixed and the other'of said points being on said main lever, and said main lever being arranged upon heat demand of said thermostatic element to move the said other point located on the main lever past the said fixed point to minor valve operating positim before said main lever engages said major valve.

JOSEPH A. CERNY.

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