US2604218A - Feeder - Google Patents

Description

July 22, 1952 I MARTIN 2,604,218

' FEEDER Filed June 5, 1947 4 Sheets-Sheet 1 EUGENE M. MARTIN BY UfiWdu INVENTOR.

July 22, 1952 2,604,218

E. MARTIN FEEDER Filed June 5, 1947 4 Sheets-Sheet 2 INVENTOR.

EUGENE M. MARTIN ATTORNEY July 22, 1952 E. MARTIN 2,604,218

FEEDER Filed June 5, 1947 4 Sheets-Sheet 3 EUGENE M; MARTIN A T TORNE Y July 22, 1952 E. MARTIN 2,604,218

FEEDER Filed June 5, 1947 4 Sheets-Sheet 4 IN VEN TOR.

EUGENE- M. MARTIN A TORNE Y Patented July 22, 1952 FEEDER Eugene Martin, Wesleyville, Pa., assignor to Read Standard Corporatidn, a corporation of Dela- Application June 5, 1947, Serial No. 752,849

The invention relates to material feeding means and particularly to a reciprocating piston type feeding mechanism for delivering material to a receiver from a source of supply, in which a pressure differential exists between the receiver and the source of supply.

It is an object of the invention to provide an improved feed mechanism of the type described wherein an effectual seal is maintained at all times against escape of pressure past the feed mechanism.

A further object of the invention is to provide an improved feed mechanism of the type described wherein friction incident to operating the feed mechanism is minimized, while maintainingan effective seal against escape of pressure past the feed mechanism.

Another object of the invention is to provide improved feed mechanism of the type described piston prior to recommunication of the feed piston with the source of material supply.

Further objects of the invention are to provide an improved feeding device that is easily assembled, conveniently arranged for replacement of parts and for lubrication; and generally to provide a practical and eiiicient feeding device.

Additional objects, advantages and features of the invention reside in the construction, arrangement and combination of parts, as will be understood from the preferred and practical embodi- T ment of the invention hereinafter described and illustrated in the accompanying drawings, in which Figure 1 is a diametric View of the invention with a quarter section broken away and shown in section;

Figure 2 is a horizontal central section through the invention with parts thereof shown in elevation;

Figure 3 is a sectional view taken on the line 33 of Figure 2;

Figure 4 is a sectional view taken on the line 4-4 of Figure 2;

Figure 5 is a fragmentaryuvertical longitudinal central sectional view of the invention showing the discharge outlet and adjacent parts of the novel material feeding mechanism; and

Figure 6 is a sectional view taken on the line E6 of Figure 2.

The invention is described hereinafter, as a 1 Claim. (Cl. 214--17) feed mechanism for finely divided coal, however, it will become apparent that it is capable of feeding various types of materials from a source of supply to a point of discharge, particularly where a differential in pressure exists between said source and discharge.

The coal pump It comprises a hollow cylindrical casing ll, preferably formed for a reason later explained, by a pair of end to end related rigidly connected cylindrical housing sections i2 and i3 secured together by means of the bolts 14. The section I? is provided in its top with an inwardly extending coal intake spout l5 and the section I3 is provided in its bottom with an inwardly extending coal discharge spout It, the intake spout being best shown in Figures 1 and 3, and the discharge spout in Figures 5 and 6. The intake and discharge spouts are offset or spaced a distance apart longitudinally of the coal pump.

A boss ll, formed with the housing section [2, surrounds the intake spout IE, to which a coal hopper (not shown) is suitably secured whereby coal will feed by gravity from the hopper through the intake spout iii. A connecting discharge spout :8, preferably formed integral with the housing section is, registers with the discharge spout l6 and is adapted to be connected with a pressurized receptacle (not shown) into which coal drops by gravity from the coal pump II].

A crank case i9 is arranged in end to end relation with the cylindrical casing H, and is provided at its end adjacent the casing H with a transverse wall 20 through which it is secured to the inturned flange 2| of the housing section l2 of easing I! by means of bolts 22. The opposite end of the crank case I9 is provided with a crank case cover 23 suitably secured, as by the bolts 2 3, to the crank case 59. The end of the casing ll opposite the crank case I9 is closed by a hollow cover '25 secured to the end wall of the housing section I3 by suitable means, as by bolts (not shown), which pass through the outwardly projecting flange 27? of the cover 25.

A piston 28, mounted to reciprocate in the casing il, includes a head 29 having a rectangular shaped bore 30 extending vertically therethrough and arranged in one extreme position of the piston 28 to communicate with the intake spout l5 and in the other extreme position of the piston 28 to communicate with the discharge spout Iii. Threaded on the periphery of the opposite faces 3| and 32 of the head 29 are the longitudinally extending cylindrical sleeves 33 and 34, respectively, arranged coaxial with the cylindrical casing H.

The diameter of the sleeves 33 and 34 is such that a slight clearance is provided between the periphery of the sleeves and the inner ends of intake and discharge spouts I5 and I6 as the piston 28 reciprocates. The outer surface of the piston 28 is thus spaced from the inner wall of the cylindrical casing I I forming an annular passage 35, thereby minimizing scoring, abrasion and freezing of the piston 28 in the cylindrical casing II by the coal dust and particles that find their Way between the piston and casing during operation of the coal pump,

The head 29 of the piston 28 is provided on its opposite faces 3| and 32 with the longitudinally extending piston rods 36 and 31, respectively, preferably formed integral with the head 29. The rod 36 is mounted to slide in a bearing 38 formed with the transverse wall 20 of the crank case I9, and the rod 31 is mounted to slide in a bearing 39 formed with the hollow cover 25.

The piston 28 is operated from a crankshaft 40 extending transversely of the coal pump I and journaled in the bearings M and 42. The bearings 4| and 42 are mounted, respectively, in the removable bearing covers 43 and 44 which are secured in suitable manner, as by bolts 45, in the sides of the crank case I9 of the coal pump II).

A pair of connecting rods 46 and 41, one at each side of the piston rod 36, rotatably mounted at one of their respective ends on a crank 48, preferably formed integral with the crank shaft 40, project through respective vertically elongated slots 49 and 50 and are oscillatably mounted at their respective opposite ends on the respective opposite ends of a transversely extending wrist pin carried .by the piston head 29. The crank 48 is formed with a throw equal to one half the distance between the intake spout I5 and discharge spout I6, so that upon reciprocation of the piston 23 through the crankshaft 40 and connecting rods 46 and 47, the bore 30 of the piston head- 29 will communicate with the intake spout I5 at one extreme position of the piston 28 and will communicate with the discharge spout I5 at the other extreme position of the piston 28.

For a purpose to be later explained, the piston. 28 is preferably provided with coal receiving insert 52 fitting within the bore 30 of the piston head 29 and retained therein by engagement of outwardly projecting shoulders formed with the insert 52 and inwardly projecting shoulders formed with the sleeves 33 and 34, respectivelyl The insert 52 is readily placed in position or removed by threading the sleeves 33 and 34 back on the piston head 29. The insert 52 is open at. its upper end through which it receives coal from the intake spout I5 and is open at its lower endthrough which the coal is discharged into the discharge spout I6.

Since, as previously stated, clearance is provided between the inner ends of the intake and discharge spouts I5 and I6 and the outer surface of the sleeves 33 and 34, a pressure seal is provided about the sleeve 34 between the non-pressurized intake spout I5 and the pressurized discharge spout I6 to eliminate escape of air from the pressurized discharge spout I6 through the said clearances and consequent blow back of the coal therethrough. The pressure seal is formed by a plurality of non-metallic packing rings 51 surrounding the sleeve 34 and arranged to be received in an annular recess 58 in a cylindrical wall 59 which is disposed within and preferably formed integral with the cylindrical housing section I2. The cylindrical housing section I3 is provided with an internal annular recess 60 between the discharge spout I6 and that end adjacent the bearing cover 25, in which recess are erably formed as a separable removable unit received a plurality of non-metallic packing rings 6I fitting closely around the sleeve 34 and forming a seal preventing escape of coal laden air from the pressurized discharge spout I6 into the bearing cover 25 through the clearance provided between the inner end of the spout I6 and the sleeve 34.

From the above description it will be observed that the outer surface of the piston 28 is entirely out of bearing contact with the piston casing I I, thereby minimizing abrasion and scoring of the piston and rendering negligible the seizing or binding of the piston in the cylinder by reason of coal particles that find their way between the piston and cylinder. The construction, as described, also provides an effective seal between the non-pressurized coal intake and the pressurized coal discharge spout, permitting feeding of coal into a chamber under, for example, lbs. pressure from a source of coal that is under atmospheric pressure, with a minimum of escape of pressure and a minimum of coal blow back. The diiferential in pressure between the intake and discharge spouts may be greater or less than 150 lbs., the above example being cited merely for illustrative purposes.

The coal receiving insert 52, as shown, is preffrom the piston head 29 so that it can be replaced, should wear or damage occur, without replacing the entire head, but it is apparent that the bore 30 of the head itself can be modified to form the coal receiving unit. In order to insure complete discharge of all the coal from the insert 52 into the outlet port I6, the side walls 62 and 63 are arranged to diverge from the upper receiving end of the insert 52 to the lower discharge end thereof.

At its open upper end, the insert 52 is provided with a plurality of laterally spaced, longitudinally extending vertical ribs 64 joining the side walls 62 and 63, as best shown in Figure 3. The tops of these ribs are flush with the arcuate upper edges of the side walls 62 and 63 that define the open top of the insert 52 and serve to prevent the upper edges of the sidewalls 62 and 63 from catching against the packing rings 51 as the piston 28 reciprocates. The open lower end of the insert 52 is provided with a plurality of similar ribs 65 which serve to prevent the lower edges of the sidewalls 62 and 63 from catching against the packing rings 51.

The inner cylindrical wall 59 of the cylindrical housing section I2 is provided with an arcuate wall extension 66 disposed below the intake spout I5. This arcuate wall 66 extends partially about the piston 28 and is integrally joined with the side wall of the intake spout I5, as clearly shown in Figure 3. Clearance is provided between the wall 66 and the piston 28 sufficient to eliminate surface contact therebetween as the piston 28 reciprocates without permitting any substantial leakage of coal from the bottom of the coal receiving insert 52.

Any small amount of coal that leaks between the piston 28 and the wall 66 drops into the passage 35 from which it is withdrawn through the port 61, connected in suitable manner with a source of suction.

In operation, with the piston 28 in the position shown in Figure 1, coal will drop by gravity through the spout I5 into the coal receiving insert 52. When the piston 28 moves to its extreme opposite position, the open bottom of the insert 52 communicates with the pressurized spout 16. An annular passage 68 formed in the inner wall of the housing section l3 surrounds the piston 28 and communicates at its lower end with the spout l6 and at its upper end comrnunicates with the open upper end of the insert 52. The pressure on the coal in the insert 52 is therefore the same at the top and bottom, permitting the coal to drop freely by gravity through the pressurized spout B6, connecting spout it and into a pressurized receptacle (not shown). In this latter position of the piston 28, it is apparent that the rings 5'1 and Si by reason of their fitting closely against the sleeves 33 and 3 respectively, form a seal against release of pressure.

Upon the coal being discharged from the insert 52, a pressure will be built up in the insert 52, and to prevent the release of this pressure against the coal in the spout l5 when the piston 28 returns to its original position, thereby interfering with the free flow of coal into the insert, a vent $9 is provided which communicates with the annular passage 35. It is apparent then, that on the return stroke of the piston 28, the insert 52 will first communicate with the vent 69 before communicating with the spout [5, so that the pressure trapped in the insert 52 is released into the passage 35 and the port 551 which, as

previously stated, is connected to a source of suction. Ports 53, best shown in Figures 2 and 6, connect the interior of the cover 25 with the passage 35, permitting air under pressure that leaks by the packing 6! to enter the passage 35 and to be withdrawn through the port 67.

Means is provided for conveniently lubricating various elements of the coal pump. The bearing 39 for the piston rod 31 is connected by means of a passage 16, formed in the bearing support '11, with a grease fitting 18, while the bearing 38 for the piston rod 36 is connected by means of a passage l9, formed in the transverse Wall 29, with a grease fitting as. The wrist pin 5! is lubricated through the passage 8!, formed in the piston rod 36, from a grease fitting 32. The crankshaft bearings ti and 32 are lubricated through the passages 83 and 84 in the bearing covers #33 and 64, respectively, from respective grease fittings 85 and 8 5, and a grease fitting 81 provides lubrication for the connecting rods it and 37.

I claim:

Feed mechanism for delivering material from a non-pressurized zone into a pressurized zone, comprising a cylinder having offset intake and discharge openings communicating respectively With said non-pressurized and pressurized zones, a reciprocating piston in said cylinder, said piston being provided with a cavity communicating in one position of the piston in receiving relation with said intake opening and in another position of the piston in discharging relation with said discharge opening, said cavity expanding in cross sectional area from its intake to its discharging end, a plurality of spaced vertical longitudinally extending ribs bridging the receiving and discharge openings of the piston cavity, the outer ends of said ribs being flush with the peripheral surface of said piston, and means within said cylinder between said openings and embracing said piston to form a seal between said cylinder and piston against escape of pressure from said pressurized zone to said non-pressurized zone.

EUGENE MARTIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

Images