Interlocking liner for casting shake-out unit

Abstract: A tumbling unit (1) such as a casting shake-out unit, rotary media drum, sand reclaimer or the like, is provided. The tumbling unit includes a cylindrical outer shell (3) and a cylindrical inner shell (5). The inner liner is formed of a series of interfitting segments (9). The segments (9) each have an inner surface (13), an outer surface (15), side edges (17), and front edge, and back edges (19), and rifling (21) extending from the outer surface (15). The side edges (17) of the segments have a groove (23) formed therein which extends the length of the said edges. The grooves (23) of neighbouring segments (9) define a channel between the segments (9). A pin (25) is received in the channel (23) to urge the neighbouring segments (9) apart to form a tight interfit among the segments in a row of the liner. The retaining pin (25) has a body (41) having side surfaces (43), a top surface (45), and a bottom surface (49). A rib (51) extends along each side surface (43) which is shaped and sized to be received in the grooves (23) of the neighbouring segments (9). An arm extends upwardly from the pin body top surface. The pin arm (53) conforms in shape and size to the side profile of the rifling (21), and is positioned on the pin body to be in alignment with the rifling of the adjacent segments, to form a continuous rifling on said liner.

Description: This invention relates to casting shake-out units used to separate or remove sand from castings, and in particular, to a liner which forms the inner surface of the shake-out unit. This application is divided out from EP-1 084 780-A. In the formation of a tumbling mill, such a casting shake-out unit, rotary separator, media drum, material drier, lump crusher reclaimer, blending drum, sand screen, or the like, it is desirable to form the inner surface of the mill from segments. Thus, when individual segments wear out, they can be replaced easily and rapidly without the need to incur a significant amount of down time or expense. An example of a shake-out unit having segmented inner liners is shown in United States Patent No. 3,998,262 which is assigned to the same assignee as the present invention. As set forth in that patent, the inner surface of the unit is formed from a series of interconnected modular components. The operation of that unit, for its intended purpose, has performed highly satisfactorily. However, when the casting shake-out unit is operated continuously, the wear on the components causes the components or segments to gradually loosen. This requires a retightening of the entire formed inner surface. This retightening operation requires that the operator incur a significant amount of down time. It is desirable for the mill to operate for a longer period before the segments begin to loosen and separate. In United States Patent Nos. 4,502,808, 5,638,887 and 5,638,890, all of which are assigned to the same assignee as the present invention, the side edges of the segments are grooved to define a channel between neighbouring segments. A pin or bar is inserted in the channel. In a completed lining, the bars tend to urge the segments apart, thus creating a tight fit in the completed cylindrical lining. These have also worked well. However, the pins and the interlocking of the liner segments can still be improved. In US 5638890, each segment includes a tongue extending from opposing edges of the segment's body. Each tongue is positioned in the middle of the edge, and is not as wide as the segment body. Each segment also includes a pocket at each corner to receive at least part of a tongue of a neighbouring segment. It is an object of the invention to seek to provide an improved apparatus. According to the invention there is provided a segment for forming an inner lining of a tumbling unit, said segment being shaped and configured to interfit with neighbouring segments; said segment including a body having a first side flange extending along a first side; a second side flange extending along a second side; a front flange extending along said front side; and a back side flange extending along said back side; said flanges all having a thickness equal to approximately one-half the thickness of said segment body between said inner and outer surfaces of said segment body; said first side flange and said bottom flange having a surface generally flush with one of the inner and outer surfaces of said segment; and said second side flange and said top flange having a surface generally flush with the other of said inner and outer surfaces of said segment. The invention also provides a tumbling unit including an outer cylinder and an inner cylinder, said inner cylinder being formed from a plurality of segments according to the invention. The tumbling unit of the invention may optionally be used with the retaining pin which is claimed in EP-1 084 780-A. An embodiment of the invention is hereinafter described, by way of example, with reference to the accompanying drawings. FIG. 1 is a partial perspective end view of the tumbling unit which is claimed in EP-1 084 780-A which is partially exploded to show one segment and a pair of retaining pins removed and with inner riflings not shown for purposes of clarity; FIG. 2 is a side elevational view of the pin of Fig. 1; FIG. 3 is an end elevational view of the pin of Fig. 1; FIG. 4 is an end elevational view of a pair of the segments of Fig. 1 adjacent each other with a pin positioned between them; FIG. 5 is an inner plan view of three of the segments of Fig. 1 positioned together; FIG. 6 is a top plan view of an embodiment of an inner liner segment according to the invention; FIG. 7 is a side elevational view of a pair of the segments of FIG. 6 adjacent each other; and FIG. 8 is an inner plan view of three of the segments of FIG. 6 positioned together. Corresponding reference numerals will be used throughout the several figures of the drawings, to identify like integers. Referring to the drawings, a tumbling mill 1 is shown generally in FIG. 1. Tumbling mill 1 is preferably a mill constructed and operated in the manner disclosed in the above noted U.S. Patent No. 3,998,262 to remove sand from castings by tumbling the castings. As shown, the mill 1 generally includes an outer cylinder 3 and an inner cylinder 5. The inner cylinder 5 is of a smaller diameter than the outer cylinder 3, and the two cylinders define a space 7 between the cylinders. The inner liner or cylinder 5 is made of a plurality of interlocking segments 9 which fit together to form the cylinder 5. Importantly, and as will be described below, the segments 9 positively lock together so that segments will not fall out of the lining as they wear. This advantageously increases the time the mill may be continuously operated before it has to be shut down to tighten the inner liner 5. Each segment 9 is similar to the segments described in the above noted United States Patent No. 5,638,890. Each segment 9 includes a generally arcuate body 11 having an inner surface 13, an outer surface 15, side edges 17, and front and back edges 19. Each segment preferably covers approximately 35°-40° of arc. To space the segments 9, and hence, the inner cylinder 5, from the outer cylinder 3, each segment 9 has diagonally extending ribs or rifling 21 formed on its outer surface 15. The ribs 21 are positioned on segment 9 so that when a plurality of the segments are connected to form inner cylinder 5, the ribs from one segment abut respective ribs from neighbouring segments to provide continuous rifling along the cylinder surface. As set forth in the prior patents, the inner cylinder 5 is preferably perforated so that the sand which is separated from the castings may fall into the space 7 between the inner and outer cylinders. The segments 9 thus have a plurality of holes or perforations 22 formed therein to allow sand to fall into the space 7 between the inner and outer cylinders. A slot or groove 23 is formed along side edges 17 to receive a pin 25 which spaces the segments apart in the completed inner cylinder to tighten the fit between the segments of the inner cylinder. The pin 25 is described in more detail below. The groove 23 extends the full length of the side edges 17. To enable the segments 9 to interlock with each other, each segment includes a tab or tongue 31 extending from the approximate centre of the front and back edges 19 and generally rectangular cutouts 33 at the four corners of the liner body 11. The cutouts 33 define channels or pockets 35 when two segments 9 are placed adjacent each other along their side edges 17. The formed pocket receives the tongue 33 of a further segment 9 which is placed adjacent the two segments along the front and back edges 19 of the segments, as seen in FIG. 5. The tabs 31 extend the full width of the body 11 between the inner and outer surfaces 13 and 15. The body, however, includes a raised portion or cover 36 on the outer surface 15 which covers the cutouts 33, as seen in FIG. 4. Thus, the pockets 35 are closed on one side. When the liner 5 is assembled, the covers 36 rest on the tongues 31, thereby interlocking the segments 9 of adjacent different rows of segments. As seen in FIG. 5, the segments 9 include rifling 37 on their inner surfaces 13. The rifling is not shown in FIG. 4 for purposes of clarity. In the completed lining, the rifling helps move castings through the mill. The rifling 37 is formed on the segments so that the rifling of one row of liner segments is off-set from the rifling of an adjacent row of liner segments. Thus, the rifling or ribs 37 do not form continuous ribs or rifling along the inner surface of the liner 5. The retaining pins 25 are positioned between the side edges 17 of adjacent or neighbouring segments 9. The pins 25 are shown in more detail in FIGS. 2 and 3. Each pin 25 includes an elongate, generally rectangular body 41 having side walls 43, a top surface 45, and a bottom surface 47. The body 41 has a length substantially equal to the length of the segment side 17. So that the pin will not interfere with the interlocking of the segments 9, the pin body includes a cutout 49 on either end of the body. The cutout 49 corresponds in size and shape to the side profile of the cutouts 33 in the segments 9. A rib 51 extends along each side surface 43 of the pin body 41. The ribs 51 are sized and shaped to be received in the grooves 23 in the segment sides 17. Additionally, an arm 53 extends up from the pin body top surface 45. As seen in FIG. 4, the arm 53 is positioned on the pin body 41 such that it is aligned with the ribs 21 of the liner segments 9 when the liner 5 is assembled. Thus, the arm 53, as seen, is generally trapezoidal in side elevation (FIG. 2), and rectangular in front elevation (FIG. 3), which corresponds in size and shape to the side profile of the segment ribs 21. Thus, the ribs 21 provide for a smooth transition between the ribs 21 of the segments 9,as well as of the inner surfaces 13 of the segments 9. When the segments 9 are interconnected, the pins 25 tighten the liner or inner cylinder 5, as set forth in the above noted U.S. Patent No. 4,502,808, to lengthen the time before the segments come loose from each other due to continuous operation of the mill. The interconnection of the segments, in turn, prevents a segment from falling out when the pin wears. Thus, if a pin 25 wears, the interaction between the tongue 31 and its associated pocket 35 will prevent the segment from falling out from the inner cylinder 5. Although the segment will be loose when the pin wears through, the segment will not fall out. This will allow the operator time to normally shut down the mill to insert a new pin or segment. An embodiment of a segment according to the invention is shown in Figs. 6-8. The segments 109 include a generally arcuate body 111 having an inner surface 113, an outer surface 115, a first side edge 117a, a second side edge 117b, a front edge 119a, and a back edge 119b. A first side flange 121 extends from the body along side 117a and a front flange 123 extends along the front edge 119a. A second side flange 125 extends along side 117b and a back flange 127 extends along the back 119b. The flanges 121, 123, 125 and 127 have a top to bottom thickness of about one-half of the thickness of the segment body 111 between its inner and outer surfaces. The flanges 121 and 123 both have top surfaces which are continuations of the outer surface 115 of the segment body; and the flanges 125 and 127 have bottom surfaces which are continuations of the inner surface 113 of the segment body. Thus, as seen in FIG. 6, the body, in top plan, appears as two rectangles placed on top of each other and diagonally offset from each other. To assemble the inner cylinder from the segments 109, the segments are assembled with their flanges in overlapping relationship, as shown in FIGS. 7 and 8. As with the segments 9, the overlapping relationship of the flanges of the segments 109 will prevent the segments from falling out of the inner cylinder as the segments become worn. Although not shown in the drawings, grooves can be formed in the edge of the flange 121 and in the body side 117b to accept the pin 25. As can be appreciated, the segments of the present invention will cooperate with each other to prevent a segment from separating from the lining when a pin wears or breaks. Although the segment may be somewhat loose, the mill 1 will still be operable, at least for a short period of time, before the segment must be replaced. This will allow for a normal shut down of the machine, rather than an emergency shut down of the machine which would be needed if the segment did separate from the lining. The pin will provide a smooth and continuous transition between the plates, so that the castings and sand see only continuous substantially uninterrupted inner and outer surfaces for the lining 5 and continuous substantially uninterrupted rifling along the liner outer surface. As various changes could be made in the above constructions without departing from the scope of the claims it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Claims: A segment (109) for forming an inner lining of a tumbling unit, said segment being shaped and configured to interfit with neighbouring segments; said segment including a body (111) having a first side flange (121) extending along a first side (117a); a second side flange (125) extending along a second side (117b); a front flange (123) extending along a front side (119a); and a back flange (127) extending along said back side (119a); said flanges all having a thickness equal to approximately one-half the thickness of said segment body (111) between said inner and outer surfaces of said segment body; said first side flange (121) and said front flange (123) having a surface generally flush with one of the inner and outer surfaces of said segment; and said second side flange (125) and said back flange (127) having a surface generally flush with the other of said inner and outer surfaces of said segment. A segment according to claim 1, including a groove formed at each side to receive an elongate retaining pin (25). A segment according to claim 1 or claim 2, including rifling extending from said outer surface. A tumbling unit including an outer cylinder and an inner cylinder, said inner cylinder being formed from a plurality of segments (109) as claimed in claim 1.

Inventors: DIDION MICHAEL S, DIDION, MICHAEL S.
Applicants: DIDION MFG COMPANY, DIDION MANUFACTURING COMPANY
Application year: 2000
Main classification: B22D31
IPC codes: B22D31