US2062860A - Mud gun - Google Patents

Description

E. E. BROSIUS MUD GUN Dec. l, 1936.

Filed June 9, 1954 .8 INVENTORl y l 7% JW VM QN QN M. nl I- 3 NN NN., N. wu \\QN. ww mm k1 ma AUN hh I. v NN E @www G m.. N

Patented Dec. 1, 1936 MUD GUN Edgar E. Brosius, Pittsburgh, Pa.

Application June 9, 1934, Serial No. 729,853

1 Claim.

This invention relates to mud guns, these being used for plugging the tap hole of metallurgical furnaces, and is for a mud gun of the type wherein the piston for expelling the charge from the barrel of the gun is operated through the use of a fluid pressure cylinder.

Mud guns heretofore have been constructed wherein the piston for expelling the clay from the barrel of the gun has been operated by means of a fluid pressure cylinder, but such devices have been subject to certain limitations. place, they have had to rely for their operation on an external source of fluid pressure. Where such guns have heretofore been used, it has been necessary to have a separate installation, such as With such an arrangement, floor space somewhere in the plant had to be utilized for the boiler or other uid pressure generating means. Provision had to be made for piping this fluid pres-` sure from the central source to each possible operating position of the gun. The gun had to be connected with the source of fluid pressure through flexible pipes which were subjected to considerable wear and which constituted a source of failure to the operation of the gun at the proper time, and the possible breakage of which always constituted a hazard to workmen, particularly where the uid pressure was steam. Failure of fluid pressure interfered with the operation of the gun, so that a plugging operation could not always be effected at just the time when it was needed. Moreover, if the source of fluid pressure diminished below an operating minimum while the gun was being operated, the clay being plugged into the tap hole could not be kept under pressure.

These andnumerous other disadvantages incumbent with such types of guns led to the development of mechanically operated guns such, for instance, as those wherein the piston for eX- pelling the clay from the barrel of the mud gun was propelled by a screw mechanism, or such as those disclosed in my prior Patent No. 1,889,433 dated November 29, 1932, wherein a rack and pinion mechanism is utilized for propelling the piston.

The mechanical drives of this type have numerous advantages over the types of mud guns just described, wherein fluid pressure is used to power which operates the motor.

(Cl. 26S-42) operate them. Among these advantages is the ready portability of Vthe mud gun and the ability to operate and use it in any position without reference to a supply line for supplying fluid under pressure. such devices to hold'a charge of clay against back pressure even upon failure of the driving Guns of this character, however, are relatively expensive..due to the more expensive mechanism required,fand thev number of machine parts whichV are'employed. Moreover, the conditions under which these guns are used are such. as to cause'considerable wear to the moving parts. The refractory or mud which is used inthe barrel ofthe gun works past the piston which is provided to expel it from the barrel of the gun, andv gets into the operating mechanism. This `mud rapidly wears the mechanism, and requires that it be cleaned.

According to the present invention, the economy and simplicity of uid pressure .operated guns is attained, but all ofthe advantages of the mechanically operated guns are secured, and the difficulties heretofore encountered with fluid pressure operated guns are eliminated.

According to the present invention, the gun is provided `with a complete operating mechanism thereon, such operating mechanism comprising a fluid pressure cylinder and piston, a fluidcirculating system, a pump for circulating fluid, and a motor for driving the pump, -all of these being mounted on and forming apart of a` portable gun assembly. The invention may be readily understood by reference to the accompanying drawing which is illustrative of one embodiment of my invention,

and in which- Figure 1 represents a top plan view of a complete mud gun unit embodying my invention;

Figure 2 is a longitudinal vertical section through the unit shown in Figure l; and

Figure 3 is a more or less schematic view of a fluid circulating system,

In the drawing, 2 designates the barrel of the mud gun, the barrel being provided with a discharge nozzle or spout 3 at the forward end thereof. It is provided at the top with a filling opening 4 over which is a closure 5. Reciprocable within this barrel or cylinder 2 is a piston 6, this piston being carried on a rod 1.

Secured to the rear end of the barrel 2 is a bracket structure 8 which supports an operating cylinder 9. The cylinder 9 being disposed directly back of the gun barrel 2 and in longitudinal Another advantage is the ability of alinement therewith. At the forward end of the cylinder 9 is a gland or packing box I0 through which the piston rod 1 passes. At the rear of the cylinder 9 is a cylinder head or closure Leading into the forward end of the cylinder 9 is a pipe I2 and leading into the rear end of the cylinder is a pipe I3. The rod 1 is provided on its rear end with a piston I4 that operates in the cylinder 9. Y

Supported on top of the cylinder 9 is a motor I5. Forwardly of this motor, and also supported by the cylinder 9, is a receptacle I6 forminga the trade under the name Hele Shaw pump.

The shafts of the motor and pump are' coupled to each other and extend substantially parallel to the piston rod 1. The pump I1 is preferably located directly over the reservoir I6 and is provided with a drain pipe I8 through which seepage from the pump may be returned to the reservoir I6. Leading from the pump I1 are two pipes, the first being the pipe I2 which communicates with the forward end of the cylinder 9, and the second being'the pipe I3 which communicates with the rear end of the cylinder 9. Located between the'pipes I2 and I3 is a differential or a three-way check valve unit I9, this being a unit which is well known to those skilled in the art.

Figure 3 shows schematically the disposition of this differential valve I9 with respect to the other piping. The differential valve has one pipe 20 which leads from the reservoir to the Valve casing I9. It has one passage that connects to the pipe I2, this passage being designated 2|, and a second connection, designated 22,"which communicates with the pipe I3. As shown in Figures 1 and 2, this whole arrangement is very compact, but the diagram of Figure 3 shows the passages opened up to -aiordl a clearer understanding of the pipe connections.

In the operation of the gun, it may be assumed that the piston 6 is in the retracted position shown in Figure 2, and that the barrel 2 has been charged with a batch of clay or mud to be ejected through the spout 3. When the gun has been brought into operating position, at the front of the tap hole, the motor I5 is driven to operate the pump I1 in one direction, causing fluid to be drawn out of the cylinder 9 at one side of the piston I4 and forced under pressure into the opposite end of the cylinder 9 through the pipeI I3 to propel the piston 6 forwardly. Since the displacement of the piston rod 1 has to be compensated for in the movement of the piston rod in this direction, additional fluid is drawn from the reservoir I6 and pumped` through the pipe I3 into the rear end of the cylinder 9 along with the iluid that is being withdrawn from the front end of the cylinder 9.

When the piston 6 has reached the forward limit of its travel, and it is desired to retract the piston 6, the motor I5 can be reversed, operating the reversal pump I1 in the opposite direction, withdrawing fluid through the pipe I3 from the rear end of the cylinder 9, and forcing it through the pipe I2 into the forward end of the cylinder. The excess fluid which is displaced by the piston rod 1 entering the cylinder is t-aken care of in the reservoir I6.

By the mounting of the driving motor and the fluid pressure pump I1 directly on the cylinder 9, Aand attaching this whole unit at the back of the mud gun barrel 2, an extremely simple and compact structure is provided which does away with any requirement for a central source of fluid pressure and which eliminates the expensive mechanical driving mechanisms that have heretofore been provided, such as screw mechanisms and racks. Should there be a failure in the power supply to the motor I5 at any time, the pressure may be maintained to hold the piston at the point it has reached in its travel. If any of the clay or mud used in the barrel of the gun escapes past the ejecting piston S, it can drop out through the opening 8a at the bottom of the bracket 8, so that it` does not interfere in any way with the operation of the gun.

The only wearing part onl which any such mud can fall is the rod 1, and the `gland I0 will function-to keep the rod clean. The fluid used is preferably oil, and since it is a closed system, loss of `oil is negligible.

I khave conventionally illustrated as the pump one form of a variable output constant speed pump, but obviously any pump system arranged -to supplylfluid to the cylinder when it is required to move the piston and bypass the Huid, but maintain the pressure, maybe employed.

`1While I have illustrated and specifically described `one preferred embodiment of my invention,'it will be' understood that various changes in the modification may be made therein within the contemplation of the invention and the scope of the following claim.

I claim:

A self-contained mud gun comprising a mud barrel unit having a discharge spout at one end and'open at its opposite end, a piston in said barrel', and a piston operating unit comprising a rigid bracket member attached to the rear of said barrel, a cylinder having its forward end rigidly secured in said bracket and positioned in central alignmentv with the longitudinal axis of the barrel, a piston in the cylinder, a rod connecting the piston in the cylinder and the one in the barrel, apump having a shaft, a motor unit having a shaft connected to the `pump shaft and carried above the cylinder, the pump shaft and the'l motor shaft being substantially parallel with the piston rod, fluid connections between the opposite ends of the cylinder and the pump including a reservoir above the cylinder and below the pump, the pump and motor unit being selectively operable to deliver fluid under pressure to either end of the cylinder. f

' EDGAR E. BROSIUS.

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