US2378883A - Control device - Google Patents

Description

P. S. RUSSEL CONTROL DEVICE June '19, 1945.

Filed March 24, 1943 Miaiiunmnn ATTORNEY f Patented June 19, 1945 c'oNTRo DEVICE Philip Sl Ru'ssel, Detroit, Mich.,-a ssignor to Detroit "Lubricatorcompany, Detroit, Mich., acorporation of Michigan Application March 24, 1943, se ial -Nes isms ir (chins- 26) Claims. Thisdhv'e'n'tion relates to new and useful impidvemerits "in liquid "level ecnt'rol devices and I morefiarticularlyto siich adevice which isfed b -a mcmramen pum ahdtvhich is pa'rticu larly adapted for suppwin liquid fuel toaflind 1 fuel burner.

thrus'tjinember er epereun u od liawh chextents upward from the ichar'nber '2 through fit guide p rture I9in the cover member '9. The rod Another obj'etis t'o p'rcvide esingie o eratin means for contr'olli gthe o'peieitiohof the "pump and 'of the safety liquid level coiitfol 'I'nans.

,muy descfibe'd hereinafter and the novelty of which will be 'iiaiticula'rly poirite'd out distinctlyclaime'd. I I

"Inthe accompanyingdrawing, to betak'e'n as a 1y illustrated a preferred 'ehibodimeiit of the inv'entio'ii, in which drawing the 'fi'giiifeis a"vie'w in let of ajpump 4, prferably'of'thefiartype. The

let cdnduitLZE having-an facihg valve seat 27 controlled jby *a vertically *reciijrocal. shfety valve member 28 which is guided forflohgitudihal I reciprocation by a capmember i t inouiitedion the tends iibward adjhcerit the float em 2 2 aim is operativly cohnecte'd theretofby a lost "fnotio'h coiihe'ction cem nsin' a 'piniifl projecting from the valve stem "and extending into "a vertic'al slot 3| in the arm 2-2. 'I fhispin andisldt lost-motion connection is such that the lost-motion. is not I taken upso as to lift the valve member 28 from I the switch 11.

ward into the chamber! rrdmthe'ehamterbettom wall is. The outlet 1 from theiiump 4 "discharges ih'to the chamber 2be'1ow the I liquid level therein. A drive shaftB forfthe pump extends upward through an abertur'e'in the 'eeve'rmemher 9 of the casing and isconiiectedto the "are matureo'f an electric motor I!) mounted ext'efii'ah 1y of the chambr Z al'nd oh'the cover member 9.

The motor I0 is controlled by 'a swi-tch I'IQpreferably 10f the snap acting type, having "an ope-r ating plunger I 2 I which'moves'theswitch to closed position lipon inward moveme'rit. fIhemcitorIiJ is supplied with "current through lead 'wires or conductors I3, 14 of which the cohductor 'I i connects to one terminal oftheswitch II. From the other terminal-of the switch I I a lead w'ireor.

conductor I5 connects to the motor ID to complete the motor circuit. The switch I I is preferably mounted upon the cover member 9 externally of the chamber 2 by means of a cover brack et I6. The switch operating thrust member I2 is actuated by a cam I I carried by a reciprocal itssea tz'l until there is upward movem nt of the float 2'1 beyohditsubward movern'ent which'o'pens the strainer chamber 32 together "provide a bypass conduit leading rom the liquid ehemcer to the pump in'let. The strainer bhaihberi? has "an inlet passage 33. The inlet passage "33 is provided with a check valve 35 which closes I The "chamber 2 hasan outlet 36 iitrollfed ty ariiahuallyober'ablemetering valve 31. Lead. from the outlet 36 "therefi's a pipe oriio'ridiiit 38 fO'r ddfii'ieCtiOn t0 the point of use (if the liquid in chamber 2 such; for exam le, "a fluid "fuel The epereue'n of this "device is as'fblIGWs.

ing of liquid fuel through the supply "pipe 3 4 and discharge of {the same tlirou'gh'the outlet I into the chamber '2. heee'mm'giy, the 'fioatil 'hasmoved upward "so that the e'emmemper I1 has permitted fthefpluhger I2 "to ineve outward and open the switch I I "thereby to stop the rhotor I0. Now, upon supply of the liquid fuel from the chamber 2 through the metering valve outlet 36, the float 2| will move downward and the cam member II will move the switch operating The conduit 26 cohn'ects into the ihlet strainer chamber '32 wl iichsubnliesthe I plunger l2 inward to close the switch II, thereby starting the motor Ill and the pump 4. The liquid level in the chamber 2 will be maintained substantially constant at the line L-L by reason of the starting and stopping of the pump 4 by the float 2|. If the float operation, upon the occurrence of the desired predetermined liquid level, fails to stop operation of the motor Ill for any reason, so that the liquid level continues to increase in the chamber 2, then this further increase of liquid will cause a continued upward movement of the float 2|. Since the lost-motion between the pin 30 and the lower end of the slot 3! is taken up substantially simultaneously with the operation of cam member I! to open the switch H, any further upward movement of the float 2| will lift the valve member 28 from its seat. Opening movement of valve member 28 will open the by-pass conduit from the chamber 2 to the pump inlet 3 so that there will be a recirculation of liquid from and to the chamber 2 through the strainer chamber 32. The liquid level in chamber 2 will now be maintained between the level L--L and the slightly increased level at which valve member 28 is opened, because when the discharge of liquid from the chamber 2 through the metered outlet 36 lowers the level in the chamber 2 such that the valve member 28 seats, then the pump 4, which under these circumstances is under continuous operation, will draw liquid fuel from the supply conduit 34 until the level again reaches the point in chamber 2 at which the valve member 28 will be opened.

What is claimed and is' desired to be secured by Letters Patent of the United States is:

l. A liquid level controlling device, comprising a casing having a chamber with an outlet, a motor driven pump for discharging liquid into said chamber for flow therefrom through said outlet, a float lifted byliquid level increase in said chamber and operative at two liquid levels, means to stop operation of said pump, means operable by lifting of said float to the lower of said levels to actuate said stopping means, a normally ineffective discharge conduit for flow of liquid from said chamber, means for overtravel lifting of said float with increasing liquid level upon failure of said pump to stop, means to render said conduit effective to discharge liquid from said chamber, and means operable by lifting of said float to the higher of said levels to actuate said last-named means so that liquid will be discharged from said chamber through said discharge conduit.

2. A liquid fuel supplying safety device, comprising a casing having a chamber with a submerged metered outlet for supplying fue1 to a gravity fed burner, a motor driven pump for supplying liquid fuel to said chamber at a rate greater than the rate of flow through said outlet, means controlling operation of said pump, a float responsive to liquid level in said chamber and controllin said controlling means to maintain over said outlet a substantially constant liquid level in said chamber, means for movement of said float with and upon liquid level increase above said constant level, a conduit leading from below the constant liquid level in said chamber, a safety valve normally maintaining said conduit closed, said valve and conduit being operable to discharge fuel from said chamber at a rate at least equal to the rate of fuel supply by said pump, and means operable by said float at a liquid level slightly above said constant level to actuate said valve to maintain a substantially constant slightly higher liquid level over said outlet.

3. A device of the character described, comprising a casing having a chamber, a pump having its outlet discharging into said chamber, a

motion means for movement of said float rela-' tive to said valve in operating said switch and operable by said float acting through said lostmotion means to open said valve upon increase of liquid level above said predetermined switch operating level, said by-pass conduit and said valve when open having a capacity for liquid flow sumcient to satisfy the suction of said pump thereby to maintain a higher substantially constant liquid level. g

4. A device of the character described, comprising a casing having a chamber, a pump having itsoutlet discharging into said chamber, a conduit for supplying liquid to said pump, a motor for driving said pump, a switch controlling the operation of said motor, a float supporting arm pivotally mounted in said chamber, a float responsive to liquid level in said chamber and carried by said arm, a thrust member operatively connecting said float and said switch, a conduit opening upwardly through the bottom wall of said chamber and having an upward facing'valve seat, said last-named conduit being communicatively connected to said first-named conduit to supply liquid from said chamber to said pump, a longitudinally reciprocal valve member seating on said valve seat and closing said last-named conduit, and a lost-motion connection between said arm and said valve member so that said float is operable to lift said valve subsequent to operation of said switch by said thrust member.

5. A device of the character described, comprising a casing having a chamber for liquid and having an inlet conduit opening upwardly through the bottom wall of said chamber, a pump mounted on said' wall and having its inletcommunicatin with said chamber inlet conduit, said pump having an outlet discharging into said chamber, a motor mounted on said casing and operatively connected to said pump, a switch mounted on said casing and controlling said motor, a float supporting arm pivotally mounted in said casing, a float mounted on said arm, means operableby said float to open said switch upon the occurrence of a predetermined liquid level in said chamber, a conduit. connecting said chamber below said liquid level to said first-named conduit, a normally closed safety valve for said lastnamed conduit, and means operatively connecting said valve and said arm, said last-named means being operable upon occurrence of a liquid level above said predetermined level to open said valve.

PHILIP S. RUSSEL.

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