US 2662256 A
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Dec. 15, 1953 A. L. GAGNE PUMP FOR FEEDING MOLTEN METAL Filed March 15, 1951 INVENTOR. Arfhur L. Gag/7e 4 TTORNEY Patented ec. 15, 1953 UITED STATES PATENT OFFICE PUMP FOR FEEDING MOLTEN METAL Arthur L. Gagne, San Francisco, Calif.
Application March 15, 1951, Serial No. 215,836 Z-CIaiIHS. (o1. 22- 70) The present invention relates to a pump for feeding molten metal and has particular reference to a pump designed for feeding molten lead or similar metal to a casting mold for making strip material and type.
Pumps of this character used heretofore consisted of a cylindrical housing having means for supporting the same with its lower end submerged in a body of molten metal, a side arm having a discharge nozzle above the level of the metal, an intake port in the side of the housing and comparatively near the level of the metal, with a float valve controlling the intake, and a piston or plunger reciprocable in the housing for drawing in metal on the upward stroke and for forcing metal through the nozzle on the downward stroke.
This arrangement had a number of disadvantages.
In the first place, the piston on the upward stroke would not clear the intake port until it approached the limit of its travel and the interim would create a vacuum sucking on the discharge port and causing undesirable fluctuations in the latter.
In the second place, the pump would draw on the molten metal comparatively near the top surface and would frequently entrain dross formed on the surface and deposit the same along the pump walls, the plunger and the discharge,
causing undue wear on piston and pump body and the leading of the molds, and calling for frequent cleaning of the elements affected.
In the third place, the suction on the exhaust side and the drossing of the metal would frequently result in an uneven flow of the metal.
In the fourth place, the drawing of the molten metal from near the top surface of the metal body would encourage the forming of dross on said surface resulting in loss of valuable tin and antimony.
And finally, the pump drawing from near the surface of the body of metal would fail to take advantage of the fact that the metal is hottest and best adapted for pumping near the bottom of the pot where the heat is applied.
In the present invention it is proposed to provide for a relatively simple improvement in the pump consisting principally in the placing of the intake valve in the bottom end of thepump thereby eliminating or at least greatly reducing the injurious results of the undesirable features pointed out, my new pump being designed to draw dross-free metal from the bottom of the pot, to insure uniformity of metal flow, to re- 2 duce the forming of dross on the surface of the body of metal, and to greatly reduce the entraining of dross into the pumped metal, thereby saving wear on the pump body, the plunger and the nozzle, and essentially preventing the leading of the mold.
It is further proposed to provide a suitable check valve at the outlet of the pump to prevent the lead previously discharged into the side arm from flowing back into the pump chamber on the suction stroke.
Further objects and advantages of my invention will appear as the specification proceeds, and the novel features of. my invention will be fully defined in the claims attached hereto.
The preferred form of my invention is illustrated in the accompanying drawing, in which Figure 1 shows a side view of my pump in position with respect to a pot of molten lead,
Figure 2., a plan view of my intake valve assembly used at the bottom end of the pump hous r Figure 3, a side view of the same,
Figure 4, a side view of a plunger used in my pump, taken at a right angle to that of Figure 1,
Figure 5, a horizontal section taken along line 55- of Figure 1, and
Figure 6, a vertical section through the nozzle used in my pump.
While I have shown only the preferred form of my invention, I wish to have it understood that various changes and modifications may be made within the scope of the claims attached hereto without departing from the spirit of the invention.
Referring to the drawing in detail, my pump comprises in its principal features a substantially cylindrical housing I having an inclined arm 2 projecting therefrom, with a discharge nozzle 3 at the upper end of the arm, and having an intake valve 4 at the bottom end thereof, and a plunger 5 reciprocable in the lower end of the cylinder and having a plunger rod 6.
The housing l is substantially cylindrical in form and has a slightly enlarged bottom end i to form a pump chamber 8. The lower end of the chamber is closed by a plug 9 threaded into the cylinder, and the valve 4 is threaded into the plug centrally, the valve having a lower axial port I B and an upper port I l of slightly larger diameter, the upper port communicating with the lower port and forming a spherically rounded valve seat I? therewith. A ball valve I3 is seated on the seat and is limited in its upward movement by a cross-pin 14 extending dia- 3 metrically through the threaded portion of the valve.
The arm 2 extends sidewise from the pump chamber 8 in an upwardly inclined direction and carries at its upper end the nozzle 3 adapted for discharge into the mold if: indicated only sketchily. The arm has a port 2 communicating with the pump chamber and the nozzle.
The housing I, above the pump chamber, is slightly reduced in diameter, as at E6, to serve as a guide for the plunger 5, then widens again, as at [7, to form two oppositely disposed windows 18, and above the windows, is provided with two lateral brackets 19, by means of which the housing may be supported with respect to a pot [9' so that the lower end of the housing is submerged in a molten body of lead provided in the pot. The latter is heated from below by means not shown.
Above the brackets, the housing is formed with opposing fiat faces 28 providing upper and lower lips or abutments 2| adapted for cooperation with an operating element in imparting a slight vibratory motion to the housing as a whole in accordance with conventional practice. The upper abutments 2| have a cylindrical top piece 22 secured thereon, this top piece having two opposing vertical arms 23 serving as guides for part or the plunger rod.
The plunger rod with its plunger 5 is illustrated in detail in Figure 4 and is of conventional type. The rod is of sufiicient length to project outside the housing when the plunger reciprocates in the pump chamber and is provided, at its upper end, with a handle 2 The rod has three registering sets of wings 25, 26 and 27, the lower wings serving as guide means within the housing and the two upper sets serving as abutments for operating levers 28 to work against. Between the two upper sets of wings the plunger rod has a pair of transverse wings 29 serving as guide means between the two arms 23.
The general structure of the housing and the plunger is substantially conventional, and the principal novel feature of the present invention lies in the arrangement of the intake valve at the bottom end of the housing which allows the pump to draw on the lower level of the molten metal, where it is most liquid due to the application of heat from the bottom and where it is clear of dross, with the further advantages that the pump chamber is full of liquid metal at all times, resulting in a smoother and more uniform flow, that less dross is formed on the surface of the metal due to reduced agitation and that no dross enters the pump chamber or the discharge.
It is apparent that the valve at the bottom should be made or" the best material available, preferable specially treated alloy steel, hardened to withstand the heat of the metal in the pot.
As a further feature of the invention I provide a check valve 30 in the lower end of the port 2, this valve being substantially similar to the intake valve 4 and serving to prevent back flow of the molten lead from the port 2' into the pump cylinder on the suction stroke.
The nozzle 3 is formed with an adjustable vent as disclosed in detail in Figure 6. The main port 3| of the nozzle has a downwardly inclined branch port 32 feeding into a sleeve 33 threaded into the nozzle as at 34. The sleeve is formed with two downwardly presented passages 35 and has a screw 36 threaded thereinto, the screw being operable for covering and uncovering the passages 35 to a desired extent.
1. A pump for molten lead comprising a generally cylindrical housing having a pair of fixed brackets projecting therefrom intermediate the length thereof, the brackets being adapted for resting on the rim of a pot having a body of molten lead therein to support the housing vertically within the pot, and the portion of the housing below the brackets being dimensioned to extend downwardly to a level near the bottom of the pot so as to be submerged in the molten lead, a rigid arm projecting from the submerged portion of the cylinder in an upwardly inclined direction and having a nozzle at the upper end thereof above the level of the molten lead, a plunger reciprocable in the lower end of the housing and projecting upwardly above the housing and having a handle at the upper end thereof, a pair of wings projecting from the plunger intermediate the upper end of the housing and the handle, an operating lever engaging between the wings for reciprocating the plunger, the arm having a port leading from the lower end of the housing to the nozzle, a closure for the bottom end of the housing, and an intake valve mounted within said closure.
2. A pump for molten lead comprising a generally cylindrical housing having a pair of fixed brackets projecting sidewise therefrom intermediate the length thereof, the brackets being adapted for resting on the rim of a pot having a body of molten lead therein to support the housing vertically within the pot, and the portion of the housing below the brackets being dimensioned to extend downwardly to a level near the bottom of the pot so as to be submerged in the molten lead, a rigid arm projecting from the submerged portion of the cylinder in an upwardly inclined direction and having a nozzle at the upper end thereof above the level of the molten lead, a plunger reciprocable in the lower end of the housing and having a handle at the upper end thereof, a pair of wings projecting from the plunger intermediate the upper end of the housing and the handle, an operating lever engaging between the wings for reciprocating the plunger, the arm having a port leading from the lower end of the housing to the nozzle, a closure for the bottom end of the housing, and an intake valve mounted within said closure, the arm having an outlet valve at the lower end of its port.
ARTHUR L. GAGNE.
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