US2129570A - Method and apparatus for making well casings - Google Patents

Description

Sept. 6, 1938. E. F DOOLEY METHOD AND APPARATUS FOR MAKING WELL CASINGS Filed Jan. 13, 1956 2 Sheets-Sheet l Sept. 6, 1938. E. F. DOOLEY METHOD AND APPARATUS FOR MAKING WELL CASINGS Filed Jan. 15, 1936 2 Sheets-Sheet 2 lii:

'EDARDEDOOLEY Patented Sept. 6, 1938 UNITED STATES PATENT OFFICE METHOD AND APPARATUS FOR MAKING WELL CASINGS This invention relates to a method and apparatus for making well casings.

Briefly, the invention contemplates a perforated well casing of the type suggested that is characterized by the power to resist such degenerative natural influences as rust and electrolysis.

Also, a perforated casing embodying the invention will be found to be marked by the presence of a plurality of longitudinally and circumferentially extending members which serve not only to strengthen and reinforce the casing but which provide a gating in which there is a quick and easy flow of the metal from which the casing is molded and in this way, the casting operation is facilitated and an improved product is achieved.

By way of further brief preliminary allusion to the longitudinally and circumferentially extending members which strengthen the casing, it might be pointed out that the arrangement of the same enables the casing to resist buckling, when being driven into place in deep wells, and to withstand external pressures created by caveins and by the surrounding formation.

In speaking briefly of the manner in which the longitudinally and circumferentially extending strengthening members assist in the casting operation, reference is made to the fact that the same 39 provide for the expeditious fllling of the mold and, while fllling, to create as little disturbance 88 possible in the metal.

Another important aspect of the invention has to do with the method and structure by which 35 the casing is cast. For example, it is required that each cheek of the flask, with a slotted ring pattern therein and rammed up, be transferred from the mold board to the drag or to a preceding cheek before the slotted ring pattern is drawn 40 so that when this ring is drawn, the core within the cheek being handled will be supported against collapse by the molding sand immediately below.

On the other hand, if the slotted ring pattern were drawn from the sand prior to placing the cheek in final molding position, an attempt to move the cheek to such position would result in the collapse of the core because the core would be left without an adequate supporting connec- 50 tion with the surrounding molding sand and in fact without a realsupport of any kind.

Other objects and advantages will be apparent during the course of the following description.

In the accompanying drawings, forming a part 55 of this application and in which l ke u era s a e employed to designate like parts throughout the same,

Figure 1 is a side elevation of a perforated well casing embodying the invention, a part of the casing being broken away, 5

Figure 2 is a horizontal sectional view taken on line 2-2 of Figure 1,

Figure 3 is an enlarged detail view, in side elevation, and taken on line 1-3 of Figure 2,

Figure 4 is a fragmentary perspective of a cope 10 ring pattern which, of course, is placed at the top of the molding flask and which provides for the formation of an attaching extension at one end of the casing,

Figure 5 is a fragmentary perspective of a 15 slotted ring pattern embodied in the invention,

Figure 6 is a fragmentary perspective of a bottom ring pattern which, of course, is mounted in the drag or nowel of the. flask,

Figure 7 is a vertical sectional view through the 20 drag of the flask, rammed up and ready to be rolled over,

Figure 8-isa vertical sectional view of the dra after being rolled over, the view illustrating the removal of the lower pattern ring, 25

Figure 9 is a vertical sectional view througha check of the flask rammed up and ready to be placed in molding position on the drag or a previous'ly placed check, a portion of the core of the mold being broken away to better illustrate the associated pattern ring,

Figure 10 is a vertical sectional view disclosing a cheek of the flask rammed up and mounted on the drag, the slotted pattern ring being shown in full and dotted line positions to illustrate that it is only after the cheek of the flask has been placed in flnal molding position, either on the drag or a previously placed flask, that the slotted pattern ring is drawn,

Figure 11 is a vertical sectional view through a partly built up flask with the slotted ring pattern partly drawn from the previously placed uppermost cheek,

Figure 12 is a vertical sectional view through the rammed up cope of the flask,

Figure 13 is a fragmentary vertical sectional view through the assembled flask ready for the metal to be poured,

Figure 14 is a horizontal sectional view taken on line "-44 of Figure 13. I 50 In the drawings, the numeral 20 generally designates a hollow cylindrical casing especially adapted for use in water wells and which, as is important to observe, is cast from gray iron.

In certain parts of the country. due to the min- 5 eral content of well water and to the nature of the formations encountered in wells, the provision of a durable and efficient perforated casing for wells is a matter of considerable interest and concern. Perforated galvanized steel casings have been found to be highly susceptible to the deleterious efi'ects of rust and electrolysis. This is due in a large measure to the refined nature of the metal. Cement casings have a tendency to crumble and collapse under the pressure of cavy and other subterranean formations. However, it has been found that by casting the perforated casing from gray iron the same is better enabled to withstand the degenerative effects of rust and electrolysis and at the same time when the casing is cast from iron after the fashion disclosed herein, it will not buckle when being driven into place in deep wells or collapse under such forces as cave-ins and the pressure of the surrounding formation.

In Figure 1, the perforated casing is shown to consist of a lower end band 24, a plurality of longitudinally spaced, intermediate, circumferentially extending bands 28 and an upper band 28. Clearly, the upper band 28 is of an external diameter to fit snugly within the lower end band 24 of a meeting section or in some other part of the fluid conduit of a well.

Of course, the bands 24, 28 and'28 are all positioned about a common axis and as clearly illustrated in Figures 1, 2 and 3, such bands are intersected and joined by a plurality of circumferentially spaced, longitudinally extending major strips or members 38. In carrying out the invention, the portions of metal between the circumferentially extending bands and the longitudinally extending strips 38 are longitudinally slotted as indicated at 34. The slots define circumferentially and longitudinally spaced groups of longitudinally extending minor strips 36 between the major strips 38. In other words, the circumferentially extending bands 24, 26 and 28 cooperate with the longitudinally extending strips in the formation of a rigid and stout framework between which the groups of spaced strips 36 are located for the admission of fluid to the casing.

As previously suggested, the casing 20 has the power to resistbuckling while being installed and at the same time is enabled to resist external pressures. These attributes are accounted for by the presence and arrangement of the annuli 24, 28 and 28 and the longitudinally extending members 38, all of these parts being substantially stouter than the minor strips 36 that are surrounded by these major members.

By reference to Figure '2, it will be seen that the minor longitudinally extending strips 36 are increased in cross-section radially outward to provide maximum strength, in combination with generously proportioned openings for fluid while at the same time facilitating manufacture.

Figure 7 discloses that in manufacture, the mold board 48 of the drag or nowel 42 is formed in the upper surface thereof with an annular groove for the reception of a ring pattern 44. It is believed to be clear that the ring pattern 44 corresponds to the lower end band 24 of the casing 20 and that after the drag, with the ring pattern 44 positioned therein, has been rammed up, it is rolled over so as to occupy the position shown in Figure 8. With the drag thus rolled over, the ring pattern 44, which will be found to project slightly above the sand, is drawn so as to prepare forthe final placing of the first check of the flask.

In Figure 5, it is illustrated that the mold board 58 for each cheek flask 52 is formed with an annular concentric groove 54 receiving the otherwise free terminal portion of a slotted ring pattern 58. After mounting the ring, the cheek is rammed up. With the cheek 52 thus rammed up, and with the ring pattern 56 still in place, the check is transferred to position on the drag. That is to say, the rammed up cheek 52 with the core therein, is transferred from the mold board,

and without being rolled over, to the drag. During this transfer of the rammed up cheek to final molding position, the core of the mold is caused to remain in place through the continued presence of the pattern ring 58.

Thus, it is only after the cheek has been placed in position on the drag that the pattern ring 58 is drawn. In this way, the core.of the mold is maintained intact while being transferred from the mold board to the drag.

As illustrated in Figure 5, the slotted ring pattern 58 consists of an unbroken annulus having an axial dimension which may approximate that of each of the intermediate circumferential bands 26. From this annulus, major and minor fingers 58 and 60, respectively, depend, the fingers 58 corresponding to the longitudinally extending members 38 while the minor fingers 80 correspond to the minor strips.35.

In other words, the slotted ring pattern 58 is in the nature of a continuous annular body having groups of longitudinally extending slots opening out through the lower end thereof and defining the relatively broad fingers 58 and the intervening groups of spaced minor fingers 88.

It is clearly shown in Figure 9 that the otherwise free lower terminal portions of the fingers 58 and 60 are seated in the groove 54 ,of the mold board 50. In this way, the ring pattern is held concentric or against distortion and in properly centered position.

With the first cheek thus positioned on the drag, and the ring pattern removed, as many additional cheeks may be added as are necessary to provide for the casting of a casing of the required length. For example, if each ring pattern is six inches long, it is a simple matter to provide six cheeks for the casting of a casing three feet long, due regard being had, of course, for the end bands 24 and 28.

Of course, in making up the mold, the ring pattern 56 is arranged with the fingers 58 and 68 in the line of the corresponding cavities below.

The ring pattern 56 has an axial dimension somewhat greater than that of the surrounding cheek so that the top of said ring pattern may be flush with the top of the cheek while the lower portion of the pattern projects below the cheek and into the annular cavity immediately below.

It is important to observe that, with the addition of each cheek, it is required that the slotted ring pattern be allowed to remain therein until the cheek is transferred from the mold board to a preceding cheek. With the cheek thus placed in final molding position, the slotted pattern ring may be drawn because the core of the mold will then be supported against collapse by the molding sand immediately below or by other means employed for this purpose. That is to say, each cheek, after being rammed up, and with the ring pattern therein, is transferred from the mold board to final molding position and during this transfer, the core of the mold is temporarily amasvo supported against collapse by the surroundins ring pattern.

After therequired number of cheeks have been placed in final molding position, the flask is coped, attention in this connection being invited to Figures 12 and 13. In Figure 12, it is illus trated that the mold board 10 of the cope is formed with an annular groove I2 adapted for .the reception of one edge portion ofthe ring pattern I4. Of course, the pattern ring 14 corresponds to the attaching portion 28 of the casing.

with the pattern ring 14 thus in place, the cope I8 is rammed up and is then rolled over for the removal of the pattern ring. This is followed by the mounting of the cope on the uppermost cheek so as to complete the molding cavity for the perforated casing.

with the mold thus set up as illustrated in Figure 13, it is gated for the admission of the molten metal and in this connection it is important to observe that the cavities left in the sand by the depending fingers 58 and by the unbroken annulus of the ring pattern 56 provide for the quick and easy flow of metal to and into the various other molding cavities. That is to say, the cavities defined by the fingers 58 and the unbroken annuli at the ends of the slotted ring patterns 86 extend throughout the length and breadth of the completed casting at more or less uniformly spaced points so that the presence of the bands 24, 26 and 28 and the longitudinal members 80 in the completed article not only strengthen and reinforce the article itself but at the same time provide for ready gating, with the result that an improved article is achieved and the percentage -of rejections is reduced.

Figure 13 illustrates my method of pouring the mold which provides for gating at the joint of the first and second cheeks, on the inside, of course, although the mold could be poured from the outside by the use of a larger flask to allow for the gate sticks and the runner.

The runner which is designated by the numeral 250 is of annular form and is located at the point of connection of the first and second cheeks. I

Also, the gates 252 are shown to radiate from the runner 250 and connect with the molding cavity at the points originally occupied by the unbroken annuli of the molding rings and in line with the members 88. In this way, I provide for the flow of metal into the cavity at the points where its rapid and uniform distribution is assured. The gate sticks or sprues 260 extend downward from the top of the cope to the runner and, obviously, serve for the conduct of the molten metal from the ladies or the like to the runner.

From Figures 1 and 3, it will be seen that although the spaced circumferentially extending reinforcing bands 24, 28 and 28 have a greater wall thickness than the longitudinally extending strips 30 and 36, the outer surfaces of such bands are flush with the corresponding surfaces of the strips to avoid protruding ribs or other projections on the exterior of the casing which might interfere with the introduction of the casing into a well. That is to say, the reinforcing bands are flush with the outer surfaces of the strips 30 and 88, to provide a casing having a smooth external surface, but project radially inward beyond the inner surfaces of the strips to give the required strength.

From the foregoing, it will beseen that the manufacture of the well casing from cast iron provides the power to resist the deleterious influences encountered in wells in various parts of the country, while the presence of the bands 24, 28 and 28 and the union of these bands with the longitudinally extending members, 30 provides the strength necessary to withstand buckling and external pressures and at the same time, such members 24, 28, 28 and 80 lookto expeditious. simplified and less costly manufacture through providing a place for the gate.

Having thus described the invention, what is claimed is:

1. In a pattern for casting slotted cylindrical well casings with circumferentially spaced, longi-' tudinally extending members and with circumferentially extending annular bands intersecting and joining the longitudinal members, an unbroken annulus which when rammed up in a section of a flask forms a molding cavity for the formation of a circumferentially extending strengthening band, said pattern also being provided with a plurality of longitudinally extending portions depending from the annulus and spaced about the circumference of the pattern to define circumferentially spaced, longitudinally extending places for the gate during casting and to give to the casing a plurality of longitudinally extending members, the pattern between said depending iongitudinally extending portions being provided with a plurality of slots spaced apart less than the widths of the individual depending longitudinally extending portions to define fingers looking to slots in the casing.

2. In a structure for casting slotted well casings in molding sand, a ring pattern having at its upper end an unbroken annulus and a plurality of slots extending longitudinally of the pattern from the unbroken annulus and opening out through the lower end thereof to define an annular series of fingers, a mold board having an annular groove receiving the lower terminal portions of said fingers to hold the ring pattern concentric and in place and to cause the lower terminal portions of the fingers to project below the molding sand, and a cheek flask receiving the pattern and having the upper edge thereof flush with the top of the pattern.

3. In a pattern for use in casting slotted cylindrical well casings with circumferentially spaced, longitudinally extending members and with circumferentially extending, annular strengthening bands intersecting and joining the longitudinal members, an unbroken annulus which when rammed up in a section of a flask forms an annular molding cavity for the formation of a circumferentially extending strengthening band, said pattern also being provided with a plurality of longitudinally extending portions depending from the annulus and spaced about the circumference of the pattern to define circumferentially spaced, longitudinally extending molding cavities communicating with said annular molding cavity for defining the circumferentially spaced, longitudinally extending members of the well casing.

4. The herein described method of casting from metal a cylindrical casing having a series of circumferentially spaced longitudinal slots interrupted by longitudinally spaced circumferential bands, which comprises providing a plurality of mold sections, forming mold cavities in the mold sections by means of removable patterns, said mold cavities each comprising an annular channel opening to one edge of the mold section and a-plurality of spaced longitudinally extending channels connecting the annular channel with the opposite edge of the mold section, assembling said mold sectionswith the annular channel of the mold cavity of each section in alignment and direct communication with the ends of the spaced longitudinal channels of the mold cavity of the next adjacent section, and pouring molten metal into the mold cavity formed by the assembled mold sections.

5. The herein described method of casting from metal a cylindrical casing having a series of circumferentially spaced longitudinal slots interrupted by longitudinally spaced circumferential bands, which comprises providing a plurality of mold sections, forming mold cavities in the mold sections by means of removable patterns,

the mold cavity in one of said sections comprising an annular channel opening to one edge of the mold section and the mold cavity in each of the other sections comprising an annular channel opening to one edge of the mold section and a plurality of spaced longitudinally extending channels connecting the annular channel with the opposite edge of the mold section, assembling said mold sections with the annular channel of the mold cavity of each section in alignment and direct communication'with the ends of the spaced longitudinal channels of the mold cavity of the next adjacent section, and pouring molten metal into the mold cavity formed by the assembled mold sections.

6. The herein described method of casting from metal a cylindrical well casing having a series of circumferentially spaced longitudinal slots interrupted by longitudinally spaced circumferential bands, which comprises providing a plurality of mold sections, forming mold cavities in the mold sections by means of removable patterns, said mold cavities each comprising an annular channel opening to one edge of the mold section and a plurality 01' spaced longitudinally extending channels connecting the annular channel with the opposite edge of the mold section, assembling said mold sections with the annular channel of the mold cavityof each section in alignment and direct communication with the ends of the spaced longitudinal channels of the mold cavity of the next adjacent section, the annular channels having a greater thickness than the longitudinally extending channels and projecting radially inward beyond the longitudinally extending channels, and pouring molten metal into the mold cavity formed by the assembled sections.

'1. The herein described method of casting from metal a cylindrical well casing having a series of circumferentially spaced longitudinal slots interrupted by longitudinally spaced cir- .cumferential bands, which comprises providing a plurality of mold sections, forming mold cavities in the mold sections by means of removable patterns, said mold cavities each comprising an annular channel opening to one edge of the mold section and a plurality of spaced longitudinally extending channels connecting the annular channel with the opposite edge of the mold section, assembling said mold sections with the annular channel of the mold cavity of each section in alignment and direct communication with the ends of the spaced longitudinal channels of the mold cavity of the next adjacent section, the annular channels having a greater thickness than the longitudinally extending channels, and the longitudinal channels at spaced points about the circumference of each mold section being of greater width than the intervening longitudinal channels, said wide longitudinal channels of the several mold sections being arranged in longi tudinal alignment, gating the mold at the annular channel of one of the mold sections in line with one of the wide longitudinal channels thereof, and pouring molten metal into the mold cavity formed by the assembled mold sections.

EDWARD F. DOOLEY.

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