US743007A - Safety gas-burner. - Google Patents

Description

No. 743,007. PATENTED NOV. 8, 1903. A. A. LUVBJOY.

SAFETY GAS BURNER.

APPLIOATION FILED MAY 13, 1903.

N0 MODEL. 2 SHEETS-SHEET l.

N0. 743,007. l PATENTED NOV. 3, 1903-.'

A. A. LOVEJOY. SA'FETY GAS BURNER. APPLICATION FILED MAY 1a, 190s.

No MODEL. 2 SHEETS-SHEET 2.

Patented November 8, 1903.

PATENT OFFICE.

ALFRED A. LovEJoY, oF LOWELL, MASSACHUSETTS.

SAFETY GAS-BURN ER.

SPECIFICATION forming part of Letters Patent No. 743,0()7, dated November 3, 1903.

Application filed May 13, 1903. Serial No. 156.954. (No model.)

. of Lowell, in the county of Middlesex and gas-burner with my invention attached. Fig. 2 is an elevation'of the same burner as viewed.

State of Massachusetts, have invented certain new and useful Improvements in Safety Gas-Burners,of whichthe following is a speciication.

This invention relates to anautomatic cutod for gas-burners, and has for its object to provide a simple andefcient device by which the liow of gas to the burner may be' stopped in case the llame is extinguished. The dame may also be extinguished andthe flow of gas may be stopped by closing the valve by hand.

My invention is shown in the accompanyingdraWingS, in which-.-

Figure lis an elevation of a front view of a from-the right. Fig. 3 is an 'elevation of a portion of the same burner as viewed from the left with part of the thumb-piece of the cock or valve cut away.' Fig. 4 is a part-sec tional View from the same point of view as Fig. 1, but with the gas turned off. Fig. 5 is an enlarged sectional View of the pawl and spring shown in Fig. 3. Fig. 6 is a view of the coiled spring and sectional gear shown in Fig. 2. Fig. 7 is a View corresponding to Fig. l of a modified form of my device. Fig. 8 shows a view as from the right of Fig. 7. Fig. 9 is a part-sectional yview at line X Y of Fig. 7l Fig. 10 is a sectional view of Fig. 7, but with the gas turned o.

Referring to the drawings, A represents a common form of gas-burner, through which runs the passage a from the source of gassupply.

B is a fish-tail gas-tip.

C is the flame.

D shows a form of valve-stem which passes through a cross-boring in burner A and across passage a. D is cut away at the top and bottom at the point where it crosses passage a, as shown in Fig. 4, so that a turn to the right or left permits the ilow of gas to the tip B.

`Any common form of gas-valve may be used,

however. D carries at one end, in such a way that it may be turned thereby, a thumb-piece or key E, by which the gas may be turned on or o by hand. The portion Fof the valve-stem D is made smooth and circular in form and is cut away to' form a notch or` engaging tooth f, into which a pawl G, pivotedto the burner A at Ag, may drop, and thereby prevent the valve being turned back after it has been turned beyond a certain point. Pawl G is normally pressed down and against F bythe spring-thermostat H. This spring H is shaped somewhat like an interrogation-point and is firmly attached to the top of burner A by means of a collar' or by any other suitable means. Spring H thus rises somewhat above the tip B, then curves' over and out ofthe llame C and extends down alongside burner A, as shown in Fig. 4, and ends in the tail h,

which is made at an angle to pawl G, and is adapted to pass through a hole or slot therein, as shown in Fig. 5. Spring-thermostat H ispreferably made of strips of two metals which expand unequally, such as brass and steel, as shown at h and h2 in Fig. 5, whereby it tends to straighten when heated and to curl up when cooled. By this construction when the dame is lighted it heats the upper portion of spring H, causing it to expand and tend to straighten, and thus to move tail h away from the burner A, as shown in Fig. l and by the dotted llines in Fig. 5. This movement forces tail h through slot and by rea. son of its angular position tail h thus causes pawl G to rise, as shown in Fig. 5. Thus spring H when cold presses pawl Gr downward and when .h0t lifts it.

Valve-stem D. carries at its end which is opposite to keyE a sectional gear K, adapted to rotate said valve-stem and to be rotated thereby. The sectional gear L, pivoted to a projection y on burner A, meshes with gear K and'is limited in its movements by projections Z Z, adapted to strike against K. This sectional gear forms one arm of a lever pivoted at y, the other arm of said lever being M.

N is a spiral-spring thermostat and is attached near the top of burner A to a projection z thereon. This spiralspringN, as will be observed, has more convolutions than springH, and this fact makes it more sensi tive to heat and cold than is H. Spring-thermostat N is also preferably made of strips of two unequally-expanding metals, as shown by n' and tn2 in Fig. 6, whereby it tends to straighten when heated and to curl up when cooled. The coil of spring N also projects ICO into naine C, and its'tail n is passed thro-u gh an orifice in a ring-m at the free end of arm M the supply of gas is thus shut off, and there is no iiame at the ti`p B. 1 The tension of spring N when cold is in theldi-rection to keep the' parts in the position shown in Fig. 6 by the full lines, and it must be strong enough to close valve D; but when it is heated by llame C it expands, its 'coil tends to straighten, as

shown in Fig. 2 and by the dotted linesin Fig. 6, and itsl tension is inthe opposite direction, therefore tending to keep the valve open, allowing the gas to pass to tip B. -The stops Z and Z'are adapted to limit the movements of valve-stem D to a quarter-turn of ninety degrees or to such other limited movement as is desired. g y

-The operation is'as follows: The thumbpiece Eis turned to the right against the pressure of spring N until pawl G is forced into notch f by'spri-ng H, thus keeping the valve open until the gas is lighted. When the gas is lighted, the heat from tiame C causes both springs Hand N to expand; but as springN has. more convolntions it expands more vrapidly, and when it expands its normal pressure is reversed or neutralized, as explained, and it now holds the valve D open instead of keeping it closed, as it does when cold. The spring H, expanding'inore slowly, gradually forces tail 7L into its opening :c in pawl G, thereby lifts G out of notch f, and thus leaves valve D free to be turned back except forthe pressure of spring N. Now if from any cause, either from its being blown out, air getting into the pipes, or by the gas being shut oi at some remote point, the tlame C is extinguished both .springs H and N begin to cool, contract, and resume their normal positions; butspring N, as explained, having more convolutions, acts more quickly than spring H, and yso closes the valve D far enough for notchfto pass under the end of'pawl G before G can be forced into it, and finally valve D is entirely closed, th'usleaving the parts iu their original positions with the gas turned off.

Figs.'7, 8, 9, and IO show a different form of latch device to holdopen the cock when the gas is first lighted. Instead of having notch f the portion F of key E is smooth. Pawl G is replaced by a sexnicircular `catch P, which is carried at one end by the lower end of spring thermostat H and y passes around burner A through a guide o. The free end of catch P is bent to form a shoulder-p and is arranged so that arm M will slide along the outer surface of P against the normal pressure of spring H and be caught and v held by shoulderp at the point where valve D is open, thus keeping valve D open until catch P and shoulder pare withdrawn from contact with arm M. When cold, springthermostat H tends to press catchP toward and against arm M; but when heated its pressnre'is reversed and carries catch P, and'thus shoulderp, awayfrom M, thus leaving springthermostat N in full control of valve D, asin the first-described construction.

Other kinds of catches operated by the spring-therinostatI-I will occur to mind wherein the reversing of the tension of the thermostat is utilized to tirst hold the gas-valve open yand to then gradually free it.

In the device shown the tops of springs H and N do not reach far into the tiame, but are protruded only into the blue fiame at the base near the tip. This arrangement insures a lower degree of heat on the springs and a greater uniformity of temperature. The lower -degree of temperature/.is desirable to prevent the springs being burned out or weakened,'as they might be by a high teinperature. The springs may be made of brass and steel or of any other suitable metals of unequal expansion.

My invention may be used upon the burners of gas-stoves or upon any other class of burners and with any kind of tip.

The characteristic features of my invention arethe use of two spring-thermostats, each of which exerts pressure when cold in one direction and when heated in the opposite direction. One thermostat is adapted to contract and expand more rapidly y than the other, and this one is adapted by suitable connections to hold the gas-burner valve closed when cold and open when heated. The other thermostat is adapted to work more slowly and to operate a catch or pawl by forcing it into contact with some of the moving parts connected with the quick thermostat, so as to hold the gas-valve open until` said quick thermostat is heated and its direction of pressure is reversed, and after that occurs as the slow thermostat slowlyheats it withdraws said catch or 'pawl, thus leaving the valve free to close, except for the pressure of the lquick thermostat. This catchth'ermostat also works slowly enough when the gas-flame is extinguished to allow the gasvalve to be closed by the quick thermostat before the catch reaches a position to interfere therewith.

Instead of one thermostat being made with more convolutions than the other, in order to vary their respective speeds in acting, one may be made of heavier or thicker `metal 'than the other, as that one will naturally heat and expand more slowlyvand cool and contract more slowly than the lighter or thinner one.

What I claim as my invention, and desire to cover by Letters Patent, is-

l. In a safety gas-burner, a cock or valve to regulate the flow of gas, a key or thumbpiece for turning said valve by hand, a sectional gear carried by one endof the stem of said valve, a lever pivoted near its center to the burner and formed with one arm a seg- IOC IOS

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mental gear meshing with the first-named segmental gear, combined with a springthermostat adapted to throw the other arm of said lever in one direction when the thermostat is cold and in the opposite direction when heated, whereby said valve is controlled by said thermostat.

2. In a safety gas-burner, a cock or valve to regulate the ow of gas, a key for turning said valve by hand, a segmental gear carried by one end of the stem of said valve, a second segmental gear pivoted to the gas-burner, stops at each end of said second gear to limit its movement, an oppositely-extending arm integral with said second segmental gear, a ring carried by and integral with the free end of said arm, combined with a springthermostat attached to the top of the burner and adapted to be heated by the gas-flame when lighted and so adjusted that its free end passes through an opening in said ring whereby the valve is controlled by the thermostat.

3. ln a safety gas-hurnera spring-thermostat part of which is near the tip of the gasbnrner and is adapted to exert pressure in one direction when cold and in the opposite direction when heated, a catch carried by the free end of the thermostat and normally adapted to lie yieldingly in the path of one of the attachments of the gas-valve to prevent the gas-valve from being closed after it has been opened, until after the thermostat is heated by the gas-flame and the catch is withdrawn by the expansion of the thermostat, combined with said attachment, a valve, and a key, as described.

4. In a safety gas-burner, a gas-valve, a key thereto, a notch in said key, a pawl adapted to enter said notch when the gas-valve is open, combined with a spring thermostat adapted to press said pawl into said notch when the thermostat is cold and to lift the pawl therefrom when the thermostat is heated.

5. In a safety gas-burner, a gas-valve, a key thereto, a notch in said key, a pawl adapted to enter said notch when the gas-valve is open, combined with a spring-thermostat attached to the burner near its tip, and a tail or tang at the free end of said thermostat formed at an angle to said pawl, an orifice through said pawl through which said tail passes, whereby when the thermostat is cold it presses said pawl down into and when heated, lifts it from said notch.

In a safety gas-burner, a cock or valve adapted to be opened or closed by hand to regulate the flow of gas, a spring-thermostat part of which is close to the gas-flame and is adapted to cause pressure in one direction i when cold and in the opposite direction when heated, con nectin g devices between said thermostat and valve whereby said thermostat keeps the 'valve open when the thermostat is heated and rapidly closes it when the thermostat cools, combined with a second thermos-tat part of which is near the tip of the gas-burner and is adapted when cold to force 'a catch into position to prevent the gas-valve from being turned back after the gas has been turned on and to slowly release said catch when the flame is lighted and this thermostat is heated, and said catch, as described.

7. In a safety gas-burner, a cock or valve adapted to be opened or closed by hand to regulate the flow of gas, a spring-thermostat `part of which is close to the gas-dame and is adapted to cause pressure in one direction when cold and in the opposite direction when heated, and connecting devices between said thermostat and valve whereby said thermostat keeps the valve open when the thermostat is heated and rapidly closes it when the thermostat cools, combined with a notch in closed when cold and open when heated, com- A bined with a slow-acting thermostat adapted to hold said valve open when the gas is first turned on and until the action of the first thermostat is reversed and to then releasel said valve as described.

9. ln a safety gas-burner, a valve D adapted to control the supply of gas, key E adapted to control valve D and provided with a notch f, a pawl G adapted to enter notch f whereby valve D may be held open, slow-acting thermostat H adapted to be .actuated by the gas-flame and provided with an inclined tail h adapted to enter an orifice :n in pawl G whereby pawl G is raised or lowered, combined with a small sectional gear K carried by valve D, a large sectional gear L adapted to mesh with small sectional gear K and provided with stops Z and Z to `limit its moveme/nt, an arm M which is an opposite extension of and integral with gear L pivoted tothe burner and carrying bearing m at its free end, and a quick-acting thermostat N provided with tail n adapted to enter an orifice in bearing m whereby valve D is opened and closed as thermostat N is heated or cooled, as described.

In testimony whereof I have affixed my signature in presence of two witnesses.

ALFRED A. LOVEIOY.

Witnesses:

JOHN A. GATELY, JOHN KEARNEY.

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