US2275202A - Pump for molten metal - Google Patents

Description

, 1940 5 Sheets-Sheet l flilii W. P. V. ROSS Filed July 3 March 3, 1942.

- PUMP FOR MoLTEN METAL March 3, 1942. w. P. v. ROSS PUMP FOR MoLTEN METAL Filed July 3, 1940 5 SheeS-Sheetl 2 March 3, 1942.

W. P. V. ROSS PUMP FOR MQLTEN METAL Filed July 5, 1940 5 Sheets-Sheet 3 March 3, 1942. w. P. v. Ross PUMP FOR MOLTEN METAL Filed July s,i 1940 5 Sheets-Sheet 4 illlllllllh March 3, 1942..

W. P. V. ROSS PUMP FOR MQLTEN METAL Filed July 3, 194()` 5 Sheets-Sheet 5 Patented Mar. 3, 1942 PUMP FOR MOLTEN METAL Y William P. V. Ross, Battle Creek, Mich., assignor to Duplex Printing Press Company, Battle Creek, Mich., a corporation of Michigan Application Ju1ya1940, serial No. 343,905' h vv(o1. .z2-7o) 15 Claims.

This invention relates to automatic pumps for molten metal or the like, and is particularly adapted for use in pumping molten stereotype metal from a melting pot into molds for casting printing plates for printing presses, although the pump is obviously not restricted to such use; and the principal object of the invention is to provide a pump of the above type embodying certain novel features hereinafter set forth.

I will explain the invention with reference to the accompanying drawings which illustrate one practical embodiment thereof, to enable others familiar with the art to adopt and use the same; and will summarize in the claims the novel features of construction, and novel comi Fig. 6 is a vertical section on the line 6 6,

Fig. 5.

Fig. 7 is an enlarged top plan View of the pumping cylinder, detached.

Fig. 8 is a vertical section on the line 8 8, Fig. 7.

Fig. 9 is an enlarged horizontal section on the line 9 9, Fig. 1, showing the means for actuating the walking beam of the pump piston rod.

Fig, 10 is a rear elevation of the parts shown in Fig. 9.

Fig. 11 is an enlarged vertical section through the loading door on the line II I I, Fig. 1.

Fig. 12 is an enlarged elevation showing the valve operating mechanism, taken on the line |2 a2, Fig. 1.

Fig. 13 is a top plan view of the parts shown in Fig. 12.

The pump preferably comprises a. substantially rectangular casing consisting of a lower portion and an upper portion. The lower por- I tion of the casing comprises a base I, a front wall 2, a rear wall 3 and side walls 4 and 5 respectively, connected at their lower ends to the base and connected together along their vertical The top of the f edges in any desired manner.

'pot

lower portion of the casing is open and' rectangular frame 6 is mounted therein secured to the upper ends of the wall members respectively, said frame providing an inwardly directed flange. In the lower portion of the casing is a grate 8 (Fig. 1), the space below which is accessible through an ash pit door 9 disposed in the side wall 4 of the casing; also in wall 4 above grate 8 is a fire door I0 of suitable type. Preferably, wall members 2,` 3, 4, 5 are spaced double walls having heat insulating material 1, of granulated or other type, disposed in the space between said double walls, as indicated in Fig. 1. Preferably the walls 2, 3, 4, 5 of the casing above grate 8 are lined with re brick II 'extending upwardly to the underside of frame member 6, as indicated in Fig. 1. l

Suspended from frame 6 is a melting pot I2 vof substantially rectangular shape having an external peripheral flange I2a at its upper end seating upon the top of frame said pot closing the upper end of thelower portionof the casing. A ue I3 is provided in the rear wall 3 adjacent the upper end adapted to be connected to'a suitable stack or the like fornproducing draft within the flrebox below the pot I2 and for removing the'smoke'fumes. n.

Removably mounted upon the lower member of said casing is ,an upper member comprising a cover I4 having side walls overlapping the sides of thev casing outside the periphery of flange IZa of melting pot I2, as shown in Figs. 1 and 11, v

said cover also having a top I4a so as to form a substantially closed chamber over pot I2. Cover I4 is provided with a flueV I5 forremoving fumes and `gases from the molten metal in I2. Preferably cover I4 is also heat insulated as shown in Fig. 11 by means of insulation I1, similar to insulation I, for the purpose of preventing loss of heat by excessivel radiation.

In the loading side of 'cover I4 is a swinging door I6 (Figs. 1 and 1l) pivoted on a horizontal axis adjacent the top thereof so that said door can be swung inwardly as hereinafter described to permit the operator to skim the dross from the surface of the molten metal in pot I2, andr said door being sufficiently large to permit insertion of a used stereotype plate P (Fig. 11) for the purpose of re-melting to replenish the melting pot I2 with metal M. Door I6 is preferably also double-walled withv heat insulation therebetween, in a manner similar to the walls of the cover.

Extending over the top of coverk I4, when positioned upon the casing, kand extending down the rear walls of the cover and casing, is a removable hood I8, having an enlargement I3 at its lower end seating upon an extension Ia of base I at the rear thereof. The main portion of hood I8 is of relatively narrow width, for the purpose hereinafter described, and extending laterally from the hood on the top of cover I4 adjacent the front end thereof is an enlargement 20, for the purpose hereinafter described.

Within melting pot I2 adjacent the front of the casing is mounted a pumping cylinder 2| closed at its upper end by plate 2|a, and open at its lower end which terminates adjacent the bottom of pot I2, as shown in Figs. 1 and 6. A removable head 22 is removably secured to plate 2Ia by bolts 22a. Cylinder 2| is positioned in pot I2 by means of arms 221: and 22e formed integrally with cylinder head 22, said arms being disposed at angles to the side walls of pot I 2, as shown in Fig. 5, so as to avoid interference with the spout, hereinafter described.

Extending through a bore 22d in head 22 and through a registering bore 2Ib in plate 2Ia of cylinder 2| is a piston rod 23 (Figs. 1, 5 and 6) carrying a piston 24 on its lower end, said piston rod extending upwardly through a gland 23a (Fig. 1) in the top |4a of cover I4 and into the hood I8, opposite enlargement 2|). When piston rod 23 is at thelower end of its stroke, piston 24 is disposed below the lower open end of cylinder 2|, so that molten metal within pot I2 may freely enter the cylinder, whereby when the piston rod is raised a predetermined amount of molten metal will be forced upwardly within the cylinder and into and through spout 25 (Fig. 1) connected with an outlet 22e in the valve chest formed between cylinder plate 2Ia and a recess 22j (Fig. 8) in the underside of cylinder head 22.

Spout 25 extends through a` large opening |42: (Fig. 1) in the wall of cover I4 at the front of the casing, and preferably the portion of spout 25 projecting out of cover I4 in enclosed in a casingY 26 whichis enlarged at its inner end and is connected to the side of cover I 4 covering the opening |41', so that the hot fumes in the cover I4 above the melting pot I2 may circulate freely along and around spout 25 and prevent the molten metal therein from solidifying before same has'reached the outer end of spout 25.

A valve is providedY in the valve chest formed between the plate 2Ia and recess 22j in cylinder head 22, for the purpose of regulating the amount of molten metal forced into spouty 25 on each upward stroke of piston 24'. As shown, the valve chest communicates constantly withA cylinder 2| through two open ports 2 Ic, 2|d (Fig. '7) in plate 2 Ia within the area of recess 22]c of head 22, said ports 2Ic, 2Id permitting entry of molten metal from cylinder 2| into the valve chest. In the plate 2Ia, offset from outletY 22e, is a bore 2Ie (Figs. '7 and 8) forming a return duct for the molten metal from the valve chest to pot I2, the walls of said bore AIe extending downwardly through an exteriorr enlargementv 2| f of cylinder 2| and terminating adjacent the lower open end of the cylinder 2 I, whereby the metal discharged through said bore into pot I2 will agitate' the molten metal therein keeping the components therein well mixedwithout necessitatingY addi tional mechanical or manual means. Journaled in a bearing 22g (Fig. 8) in head 22 between the axes of bore 2| e and outlet 22er is a valve plate 22h mounted on a valve rod 22x and being of such shape and area that when one end thereof covers-the outlet 22e of head 22 the other end 75 will clear the return bore 2Ie as shown in dotted lines in Fig. 7, but when said end of valve 22h covers return bore 2Ie the other end will clear outlet 22e as shown in dot-and-dash lines in Fig. 7. Valve rod 22x is actuated automatically and may be adjusted as hereinafter described.

A walking beam is provided in the upper portion of hood I8 comprising a pair of parallel swinging levers 21, 21a (Figs. l and 2) pivoted at their centers on a bracket 28 mounted on the top I 4a of cover I 4, said levers extending from a point adjacent piston rod 23 to the rear end of hood I8. The front ends of the levers 21, 21a, are pivotally connected to a plate 23 having an elongated slot 29a in its front edge and slidably receiving a pin 30a on a head 30 secured on the upper end of piston rod 23, whereby as levers 21, 21a are swung the piston rod 23 will move up and down with an approximate straight line motion. The rear ends of levers 21, 21a are pivotally connected to a plate 3| to which is connected the upper end of an actuating rod 32 extending down through hood I8 at the rear of the casing and having its lower end pivotally connected to an eccentric pin 33a on a crank wheel 33 (Figs. 9 and 10) mounted on the driven shaft 34a of a reducing gear 34. Gear 34 is driven by an electric motor 35 mounted upon extension Ia of base I, by means of a -belt 36 running over pulleys 35h and 34h on the drive shafts of motor 35 'and reducing gear 34 respectively, as shown in Figs. 9 and l0. By the above construction, as motor 35 is actuated, the walking beam 21, 21a Will be oscillated to reciprocate piston rod 23. Preferably the hood I8 and its enlargements I9 and 20 are provided with suitable louvres as shown in Figs. l and 3 to allow circulation of air therethrough to prevent undue heating of the motor and other operating parts of piston rod 23 and the automatic Valve actuating means.

As previously stated, return duct 2|@ in cylinder plate 2Ia returns excess metal delivered by the cylinder 2| back into melting pot I2. The proportion of metal raised by piston 24 which passes into delivery spout 25 through outlet openingA 22e is regulated by the setting of Valve plate 22h within the valve chest at the top of cylinder 2| and which Valve 22h is secured to the lower end of valve rod 22x. When the full quantity of molten metal raised by piston 24 is not permitted by valve plate 22h to pass into spout 25, the overow descends through duct 2|e back into pct I2, agitating the molten metal therein and keeping its components well mixed without requiring any additional mechanical or manual means for suchpurpose. The upper end of valve rod 22:0 is journaled in a bearing 39a in a frame 39 secured to the top I 4a, of cover I4 of the casing within the hood enlargement 20. A lever 36 (Figs. 12 and 13) on the upper end of valve rod 22x within hood I8 is connected by an extensible link 3'! to a lever 33 on rock shaft 40 journaled in bearing 33h so that when said shaft is rocked, valve rod 22h will be shifted to control the relative amounts of uncovered areas of outlet 22e and the return duct 2 ie (Fig. 7) Link 31 is equipped with a threaded section 31a for initially adjusting the limits of swinging movement of valve 22h to provide different ratios of uncovered portions of outlet 22e and duct 2| e. Shaft 40 carries a gear 4| meshing with a gear 42, twice the diameter of gear 4I, said gear 42 being mounted on a shaft 43 journaled in bearing 39e of frame 39 and parallel with shaft 40. Pivoted on shaft 43 is a rocker arm 44 connected by a link 45 to one arm 46a of a bell-crank lever journaled at 47 in a bearing 39d of frame 39, the other arm 48h of the bell-crank lever having an elongated slot 46c therein which slidably receives a roller 30a: on the head 38 at the upper end of piston rod 23 .within hood I8. As bell-crank lever 46a-48h is rocked by the vertical motion of head 38, link 45 rocks the arm 44 which is freely mounted on the shaft 43 and which carvries at its outer end a hinged member 44a equipped at its free end with an elongated roller 44h freely journaled on a stud 44C, where-by as arm 44 is rocked the roller 44h will roll on the periphery of a four-toothed ratchet disk 48 having undercut teeth indicated at 48a, 48h, 48o and 48d: and in the positions of the parts as shown in Fig. 12, roller 44 would engage the uppermost tooth 48a at the top of disk 48 if such engagement Were not obstructed. Preferably disk 48 is secured directly to gear 42 so that the gear may be mounted freely on shaft 43. On the outer face of disk 48 are tWo diametrically opposed studs 48e and 48j.

A dog 55 (Fig. 12) prevents disk 48 from rotating in the wrong direction by engagement of the projection 55a thereof with the teeth 48a, 48h, 48e and 48d in succession, said dog swinging on a stud 53 as the disk 48 is rotated by roll 44h in the direction of the arrow (Fig. 12).

A guard leverA 49 is shown in Fig. 12 in its obstructing position, said lever being fulcrumed on a stud 50 Xed in the frame 39 beside disk 48, and said lever being provided with projections 49a and 49h. Projection 49D is adapted to be normally engaged by a tooth i'slbI on the upper f end of a pawl 5I, which pawl swings on a stud 52 fast in the frame 39, and is provided with a lower projection 5Ia which, until the pawl is released, engages with lowermost stud 48e (Fig. 12) on disk 4B to positively hold the disk against rotation, while the diametrically opposite stud 48j (Fig. 12) is adapted, as the disk 48 is rotated in the direction of the arrow in Fig. 12, to engage the underside of projection 49a of guard lever 49 and swing said lever so that its end 49h will be engaged by the pawl tooth 5Ib.

The edge 5Ic of the pawl 5| is engaged with a cam 52a mounted on a manually operable shaft 52 rotatably mounted in the frame 39, said shaft 52 having one end projecting through casing 20 "1* and journaled in a bearing 53 (Fig. 1) and having a crank 521) (Figs. 1 and 13) which may be equipped with the trip handle for the convenience of the operator.

Operation To operate the pump the motor 35 is actuated by closing a manually operated switch (not shown), thus reciprocating the pump piston 23 through the rod 32 and walking beam 21, 21a. The valve 22h in normal position closes outlet 22e to spout 25 causing the entire flow of molten metal from cylinder 2I to be discharged through the return duct 2Ie, thereby agitating the metal in pot I2, the valve operating parts normally bev ing in the positions shown in Figs. 12 and 13.

Enough molten metal for casting a stereotype plate must pass, through the pumping cylinder and through the outlet 22e in the valve chest to the spout 25 and into the mold or casting box (not shown), the surplus metal passing through return duct 2Ie back into melting pot I2. Normally valve 22h closes the outlet 22e and maintains the return duct 2Ie opened, the valve 22h normally assuming the position shown in dotted lines in Fig. 7.' By adjustment of link 3'I'-.3'Ia. of the 'valve mechanism the relative amount of opening of both ports 22e-2Ie may be varied, to wit, the movement of the valve 22h may be regulated to entirely close return duct 2 Ie in one position and leave outlet 22e wide open, or to close outlet 22e leaving duct 2|e wide open, or the'valve 22h may be regulated to partially close both ports. Thus the valve 22h may be initially set to deliver all the metal back to the pot I2, or to deliver all the metal to the spout 25; or with both ports partially opened to delivery only sufficient metal to the spout to forma complete plate, the surplus metal being returned to melting pot I2.

When ready to cast, the handle 52h (Figs. 1 and 13) is rotated through one complete turn (360) thereby rotating cam 52a, and swinging tooth 5Ib of pawl 5I out of locking engagement with the end 49h of guard lever 49, and lugv 5Ia of pawl 5I out of engagement with stud 48e of disk 48, thereby allowing guard lever 49 to rock on stud 50so that its outerl end lies below the tooth 48a and below the path of the roller 44h.

On the subsequent up-stroke of Ipiston rod 23, roller 44h drops into the uppermost tooth 48a of the disk 48, so that on the following downstroke the lever 44 will turn the disk 48 onequarter revolution and through the gears 42 and 4I will rotate the shaft 40 one-half revolution, and through lever 38, link 3l, and arm 36 on valve rod 22x, will swing valve 22h to uncover outlet 22e to the spout 25 and close the return duct 2Ie. The next upstroke of the piston rod 23 forces the molten metal in the cylinder into the spout 25 and causes the roller 44h to engage the next tooth 48h of disk 48 which is then in the position formerly occupied by tooth 48a. The next downstroke of piston rod 23 therefore rotates the disk 48 and gear 42 another quarter turn, thereby rotating gear 4I and shaft 48 a secondhalf revolution. During such latter rotation of disk 48 the stud 481 will engage the underside of guard lever 49 and raise said lever into position to be engaged by tooth 5Ib of pawl 5I, thus restoring the different members to the positions shown in Figs. 12 and 13 upon the completion of a full half rotation of disk 48. 'Ihus while the -piston rod 23 is reciprocated by the motor 35, the valve 22h will remain stationary and covering outlet 22e until crank 52h is again rotated to permit actuation of the valve mechanism.

I claim:

1. In a metal pump having a casing containing a melting pot having a pumping cylinder and having a continuously reciprocating piston in said cylinder; a valve chest having an inlet from said cylinder and having an outlet provided with a spout; said valve chest having a return duct discharging into the pot; a valve in said chest adapted to be moved by the piston into positions across the outlet and return duct; means for normally holding said valve in position to close the outlet and to open the return duct; and manually operable means for releasing the holding means to permit said valve to be shifted into position to close the return duct and open the outlet.

2. In a metal pump as set forth in claim 1, said holding means comprising normally inactive valve actuating mechanism actuated by the piston and adapted when activated to open the outlet and close the return duct during one pumping stroke of the piston.

3. In combination with a;pump as set forth claim 1, means for initially setting the 4valve to expose various-ratios of uncovered areas of said outlet and return duct while the molten vmetal is being passed to the spout, whereby the amount of metal passed thereinto may be regulated,y the excess pumped metal being returnedv to the pot through the return duct. i

4. In a pump as set forth in claim 1, saidholding means comprising a rotatable member journaled on said casing; means actuated byV said member for moving the valve; a ratchet on said member having peripheral teeth; Van arm pivoted coaxially of said ratchet; means for oscillating said arm; a yieldable pawl on said arm engaging the teeth of said ratchet; means for normally preventing the pawl from engagingthe teeth; and said manual means shifting the preventing means.

5. In a metal pump having a casing containing a melting pot having a. pumping cylinder and having a reciprocating piston in said cylinder; a valve chest having an inlet from said cylinder and having an outlet provided with a spout; said valve chest having a return duct discharging into theY pot; a valve in said chest adapted to be moved into positions across the outlet and return duct; normally inactive valve actuating mechanism holding the valve in position to close the outlet and to open the return duct; normally inactive means actuated bythe piston for actuating the valvel mechanism; and manual means for releasing said inactive means for actuating the valve actuating mechanism and shift the valve to close the return duct and open the outlet on one down stroke ofl the -piston, and on the next down stroke to restore the valve to normal position.

6. In combination with a pump as set forth in claim 5, means in said valve actuating mechanism for initially setting the valve into position to expose various ratios of uncovered areas of said outlet and return duct while the molten metal is being passed to the spout, whereby the amount of metalv discharged from the spout may-be regulated, the excess pumpedmetal being returned tc the pot through the return duct.

7. In a pump-as set forth in claim 5, said valve actuating mechanisrnincluding a rotatable member journaled on said casing; means actuated by e said member for moving the valve; a ratchet on said member having peripheral teeth; and said normally inactive means comprising an arm pivoted coaxially of said ratchet and` oscillated by the piston; a yieldable pawl on saidarm adapted to engage a tooth of the ratchet and rotate the ratchet a partial turn; a guard normally preventing the pawl from engaging said tooth; and said manual means shifting said guard.

8. In a metal pump having a casingv containing a melting pot having a pumping cylinder and having a continuously reciprocating piston in said cylinder; a valve chest having an inlet from said cylinder and having an outlet provided with a spout; said valve chest having a return duct discharging into the pot; a valve in said chest; means for normally holding the valve in position to close the outlet and to open the return duct; means operated by the piston for shifting the valve to pass molten metal pumped on the upstroke of the piston through the spout; and means for initially setting the valve into position to expose various ratios of uncovered areas of the outlet and return duct, wherebyY the amount of metal discharged from the pump may be regulated, the excess pumped metal returning to the pot through the return duct.

9. In a metal pump as set forth in claim 8, said holding means comprising normally inactive valve actuating mechanism actuated by the piston and adapted when actuated to open the outlet and close the return duct during one pumping stroke oi the piston.

10. In a metal pump having a melting pot containing a pumping cylinder and having a continuously reciprocating piston in said cylinder; a valve chest having an inlet port from the cylinder and having an outlet provided with a spout; said valve chest having a return duct discharging into the pot; a valve in said chest movable by the piston between the outlet and duct; said cylinder having its lower end open and terminating adjacent the bottom of the pot, and having its upper end closed; a head on said closed upper end having a recess in its underside forming with said end the valve chest; and said return duct discharging adjacent the bottom of the pot whereby the flow of molten metal from the vvalve chest into the pot will maintain the contents of the pot agitated.

1l. In a metal pump having a melting pot containing a pumping cylinder and having a reciprocating piston therein; a valve chest having an inlet from the cylinder and having an outlet and having a return duct discharging into the pot; a valve in said chest adapted to be moved into positions to cover thev outlet and return duct, said valve normally closing the outlet and opening the returnV duct; a gear journaled on said pump; means actuated by said' gear for moving the valve; a second gear meshing with the rst gear; a ratchet on said second gear having peripheral teeth; an arm besideV the ratchet; means actuated by the piston for oscillating said arm; a yieldable pawl on said arm adapted to engage a tooth of the ratchet and rotate the ratchet a partial turn; means for normallypreventing the pawl from engaging said teeth; and manual meansV for shifting the preventing' means'to permit the ratchet to-be rotated-to clese'the return duct and open'the outlet.

12. In a pump as set forth in claim il., said preventing means comprising a pivoted guard beside the ratchet normally positioned to prevent the pawl from engaging said teeth until the guard is shifted by said manual means.

13. In a pump as set forth in claiml 1l, said preventing means comprising a trip and a guard beside the ratchet and having one end normally engaging the trip and its other end positioned to bridge the ratchet tooth; said manual means when actuated shifting the trip to permit the ratchet to be turned successive partial turns; and means on the ratchet adapted to restore the guard and trip to normal positionsV after a predetermined number of partial turns.

14. In a metal pump having a melting pot containing a pumping cylinder and having a continuously reciprocating piston therein; a valve chest provided with an inlet fromthe cylinder,` an outlet, and a return duct tothe pot; a valve in said chest normally closing the outlet and opening the return duct; a rotatable member; means actuated by said member for moving the valve; a toothed ratchet on said member; an oscillating arm beside the ratchet actuated bythe piston; a yieldable pawl on said arm adapted to engage a ratchet tooth and intermittently rotate the ratchet during a down stroke of the piston; a

trip; a pivoted guard beside the ratchet normally maintained by the trip into position to bridge the adjacent tooth; and manual means for shifting the trip to permit the ratchet to be rotated and thereby close the return duct and open the outlet; said ratchet teeth being spaced 90 apart; and a pair of diametrically opposed lugs on the ratchet adapted to engage the guard as the ratchet turns and restore the guard and trip to normal positions, whereby the ratchet will be rotated through two successive quarter turns by two successive down strokes of the piston before the guard is restored to normal position.

15. In a metal pump having a melting pot containing a pumping cylinder and having a continuously reciprocating piston therein; a valve chest provided with an inlet from the cylinder, an outlet, and a return duct to the pot; a valve in said chest normally closing the outlet and opening the return duct; a rotatable member;

means actuated by said member for moving the valve; a toothed ratchet on said member; an oscillating arm beside the ratchet actuated by the piston; a yieldable paWl on said varm adapted to engage a ratchet tooth and intermittently rotate the ratchet during a down stroke of the piston; a trip; a pivoted guard beside the ratchet normally maintained by the trip into positio-n to bridge the adjacent tooth; and manual means for shifting the trip to permit the ratchet to be rotated and thereby close the return duct and open the outlet; said ratchet teeth being spaced 90 apart; a pair of diametrically opposed lugs on the ratchet adapted to engage the guard as the ratchet is turned and restore the guard and trip to normal positions; means for preventing backward rotation of the ratchet; and means cooperating with said l-ugs to prevent forward rotation of the ratchet until the trip is shifted.

WILLIAM P. V. ROSS.

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