US2094859A - Shield for burners - Google Patents

Description

Oct; 5, 1937. SUNDSTROM 2,094,859

SHIELD FOR BURNERS Filed March 15, 1935.

Patented Oct. 5, 1937 UNITED STATES PATENT OFFICE SHIELD FOR BURNERS Application March 15, 1935, Serial No. 11,182

1 Claim.

My invention relates to burners to be employed with the melting pots attached to type-casting machines of the so-called linotype class.

I aim to provide a burner which will effectively heat the outlet for the melting pot so that metal from the main pot can be discharged through the outlet spout without being cooled below the temperature desired. In prior melting pots of this character different types of devices have been employed in an effort to maintain the temperature of the molten type metal so that it will be of the proper temperature at the point of discharge. Multiple burners of different character have been used but none of them with entire and continued success. It has been found diflicult to maintain the heatthroughout the throat of the discharge spout for the metal so that it will not be cooled in the spout or in which certain portions of the spout will not become overheated.

It is an object of my invention to provide a burner along the underside of the discharge spout of the crucible and provide a shield therefor which will direct the flame upwardly along the spout at the point where heating is desired, and to control the passage of the flame so that the entire spout will be maintained in a uniform and proper temperature.

My device is intended for an attachment for the usual and ordinary type of melting pot employed with type-casting machines and formed to be attached in such manner that an even high temperature of the melting pot is maintained. The invention is an improvement over that shown in my prior Patent No. 1,931,273, granted October 1'7, 1933.

In the drawing herewith, Fig. 1 is a central vertical section through a melting pot and the burner connections and showing the adaptation of my invention thereto.

Fig. 2 is a broken sectional detail of the gas connecting pipe.

Fig. 3 is a central longitudinal section through the burner showing the shield attached thereto.

Fig. 4 is a front elevation of the burner attachment.

In Fig. 1, I have illustrated a melting pot of the usual construction. It comprises an outer housing I, cylindrical on the rearward side and having a forwardly tapered spout toward the upper portion of the forward side of said housing. Located within this housing and supported thereon in the usual manner is the melting pot or crucible 2. This is formed with a type metal container toward the lower side thereof and indicated at 3. There is a cylindrical projection at 4 toward the upper portion of the container to receive a piston employed in the discharge of the metal in the ordinary operation of the type casting, said piston not being shown for greater clearness.

The pot has a forwardly extending spout 5 thereon, said spout being of the usual form and having a wide discharge orifice at the forward end 36. This orifice is wide enough to discharge the metal for a slug of type which may be as much as five inches long or in other words in excess of two ordinary columns in width. Where the metal passing through the spout is not of the proper temperature the slug which is cast through the discharge orifice is found to be non-uniform in its structure and difliculty is experienced particularly toward the end of the slug in maintaining a good cast.

Above the crucible is a cover or top member 6 of the housing which has an opening 1 for the insertion of the metal and through which the thermostat may project, and it is to be understood that a cover of ordinary construction may be employed if desired. Toward the forward side of the upper portion 6 of the housing is a chimney 8. This chimney provides an outlet for the gases from the burner, said gases being adapted to pass upwardly around the spout and through an opening 9 to the chimney in the usual manner.

Below the crucible and supported in the frame of the housing is the main burner Ill. Said burner is directly below the main container of the melting pot. It is supplied with gas through the pipe I l, which leads through the pipe I2 by way of the thermostat 53 to the usual gas supply coming through the pipe I4 at the forward side of the housing, said connections being broken away. It is to be understood that gas coming to the main burner is thus subject to the control of the thermostat, the terminals E5 of which project downwardly into the molten metal. Where the temperature in the pot exceeds a predetermined maximum the thermostat will automatically diminish the supply of gas to the burner. This is a usual and ordinary construction and forms no part of the present invention.

As shown in my prior patent referred to above, I employ a second burner 16 forwardly beneath the discharge spout from the crucible. The difficulty encountered in the previous embodiment of this invention was that the heat was not directed forwardly along the spout toward the discharge end but passed around the spout at a lower point and equal heating was difficult to obtain.

In the present embodiment the discharge tubes I! for the burner are elongated so as to extend upwardly to a point above the usual point of application of heat, the upper ends of. the burner spouts ll being bent forwardly to discharge the flame at a point higher up around the throat of the spout. This type of burner is more eifective in discharging the gas at a higher point along the spout, but I have found that it is necessary for best results to employ a shield which I have indicated at E8 and shown best in Figs. 3 and 4. The shield is held in position about the burner spouts, of which there are two, as shown in Fig. 4, by gravity and this shield is hence easily detachable.

Said shield comprises a plate of sheet metal which is approximately U-shaped intransverse section thus providing a back member IS, the

lower end of which is curved forwardly at 2B and provided with openings therethrough to fit over the burner spouts H. The upper end of the plate is curved forwardly at 2i so as to accord with the inclination of the spout at the point where it approaches the side of. the spout. It is to be understood that there is a slight clearance between the inclined portion El and. the outer wall of the discharge spout for the melting pot. The sides of the plate it are bent forwardly, thus pro viding curved side walls 22, which direct the flame forwardly along the spout.

To assist in holding the plate upon the burner I provide a transverse pin or rod 23 shown best in Fig. 4, said pin extending through opposite openings in the side walls 22 of the shield and having the end bent downwardly at 2 3 to hold the same removably in place. The lower end of the plate at the sides is extended downwardly, as shown at 25, to flt about the burner and assist in holding the same in erect position. It will be seen that this plate is easily detachable from the burner by simply lifting it off over the upper ends of the burner spouts ll. The flame from the burner spouts ll can be carried upwardly more effectively if a small draft opening is left in the shield as shown at 26. I position this opening closely adjacent the bottom of. the shield and I thus allow access of air to the point of combustion so that a better burning of the gas is obtained.

The gas to this forward burner is through a separate pipe not controlled by the thermostat. From the pipe Hi I provide a lateral branch or bypass 2i, which is connected through a T 28 to the inlet connection 29 to the base of the burner. This portion of the burner is separate from that of the main burner as will be understood clearly from Fig. 3.

In Fig. 2 I have shown a sectional view of the T 28 and it will be noted that the lower portion of the T is connected to a rod 30 which acts merely as a connection or bracket joining the two burner pipes l2 and 21 for support merely.

By the use of my shield [8 at the rearward side of the forward burner spouts I1 I have obtained results which it has previously been impossible to obtain otherwise. The shield separates the housing below the melting pot into two chambers. The heat from the main burner It is directed entirely against the main body of the melting pot and is not influenced materially by the upward draft around the spout. The main body of metal is kept at the usual desired temperature. The temperature of the discharge spout is, however, separately controlled by my forward burner ll. The flame from this burner is directed well up toward the upper end of the shield and is inclined forwardly along the portion of the spout which must be heated. I find that the separation of this burner from the main burner by means of. the shield enables me to get a distribution of the flame effectively upward toward the forward end of the spout and that results are obtained in casting which are of uniformly satisfactory character. Even where wide slugs of type are to be cast I am enabled to obtain a uniform and solid texture in the slug throughout its length. Even slugs of type metal of more than two columns in width are found to be uniform from end to end.

The action of this shield is to prevent the discharge of the heat from the forward burner against the throat of the discharge spout close to the main pot and to obstruct the draft upwardly along the spout so that the heat is more evenly distributed around the spout, thus maintaining a uniformly high temperature and thistemperature is uninfiuenced by any connection with the thermostat.

What is claimed as new is:

A type metal casting device including a melting pot, a burner beneath the same, a discharge spout on said pot, a housing about said melting pot and spout, a heater for said pot, a heater for said spout including a fuel-conducting nozzle directed upwardly along said spout from its lower end and a shield plate on said nozzle, the upper end thereof being inclined to direct the flame upwardly along the said spout within said housing, said plate having a draft opening therein adjacent the lower end thereof.

HERMAN T. SUNDSTROM.

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