US3291306A - Concentrating table - Google Patents

Description

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United States Patent 3,291,306 (IONCENTRATING TABLE Spencer A. Stone, Fort Wayne, Ind, assignor to The Deister Concentrator Company Inc, Fort Wayne, Ind, a corporation of Indiana Filed June 28, 1965, Ser. No. 467,407 6 Claims. (Cl. 209-441) This invention relates generally to concentrating tables, and particularly to concentrating tables of the multipledeck type which are pendantly supported.

Concentrating tables of the general character referred to have two types of uses. First, there is the use for coal washing purposes, and a two-deck table suitable for such purpose is disclosed in U.S. Patent No. 3,075,644, granted January 29, 1963, to Frederick S. Ambrose. Second, there are tables intended for ore dressing purposes, as represented by Belgian Patent No. 618,405, granted December 3, 1962, to Dei-Con Eastern Corporation. While coal washing tables and ore dressing tables operate according to the same theoretical principles, their construction and their practical mode of operation are, in many respects, antithetical, as fully explained in the aforesaid Belgian patent. In each case, it is customary to provide such tables with means by which the inclination of the deck may be changed about axes which are more or less perpendicular to each other. For changes in so-ca-lled side tilt, a deck is rotated about an axis which is more or less parallel to the direction of the thrust which reciprocates the deck. For changes in so-called end elevation, a deck is rotated about an axis which is substantially horizontal, but more or less perpendicular to the direction of the thrust which reciprocates the deck.

In coal washing operations, a table once adjusted to the character of coal being processed on it is seldom changed. On the other hand, in ore dressing operations, both side tilt and end elevation, particularly the former, are subject to repeated and frequent adjustment.

The decks of such tables are forcibly reciprooated in a substantially horizontal direction and are also subject to secondary vibration which, in the case of coal washing tables, is usually insignificant insofar as concerns the practical operation, but, in the case of ore dressing operations, may adversely affect the economy of operation and the proficiency with which the table separates the small percentage of values from the large percentage of tailing.

Various means are disclosed in the aforesaid patents for accomplishing both side tilt and end elevation, and each contemplates, in a fashion, the stabilization of the decks against secondary vibration. In each case, however, the means intended to stabilize the decks against secondary vibration involves connecting one deck to another, and overlooks the possibility that such a stabilizer may cause the several decks thus connected together to vibrate as a unit, but at a different frequency and with a different amplitude than the individual decks would vibrate if unconnected with another deck. In spite of the fact that all decks of a given table may be made according to the same drawings and specifications, and within the same manufacturing tolerances, no two decks are identical with respect to vibration tendencies. Such decks and their framing are commonly constructed of wood, and consequently one deck differs from another at least to the extent that one piece of timber inevitably differs from another in spite of the highest degree of precision in selection and manufacture.

An object of the present invention is therefore to stabilize each individual deck against vibration.

A further object of the invention is to provide for adjustment of each individual deck for side tilt by means which does not influence, pro or con, the tendency of a given deck to vibrate.

The present invention contemplates, generally, a vibration stabilizer for each deck independently of another, and the provision of side tilt adjusting mechanism located substantially in alignment with the axis about which a deck is rotated to vary it in side tilt. More specifically, the invention contemplates the provision of each deck with an independent means for exerting a biasing force thereon in a vertical direction, such force being of magnitude sufficient to restrain the deck from moving under vibration in the direction counter to said force. Moreover the invention contemplates the provision of side tilt adjusting means at the mechanical thrust transmitting member which delivers force and motion from a reciprocating force generator to each deck.

In the accompanying drawings, there is illustrated a multiple-deck concentrating table of the pendantly supported type, wherein both the reciprocating force generator and the decks are suspended from a super-structure so that the entire organization is free to pendulate without transmitting vibrations to the building structure in which the concentrating table is housed. The reciprocating force generator, and the mode of suspending the table in the illustrating embodiment, is the same in principle as that disclosed in the aforesaid patents, and consequently reference may be made thereto for details not specifically disclosed herein. In the accompanying drawings:

FIGURE 1 is a perspective view of a triple deck concentrating table of the character shown in the aforesaid Belgian patent, but provided with vibration stabilizers and side tilt adjusting means constructed in accordance with the present invention;

FIGURE 2 is a view in side elevation of the type of table shown in FIGURE 1, but with different end elevation adjustment means, as Well as independent differing side tilt adjustment means, and with the collection launders removed for clarity of illustration;

FIGURE 3 is an end elevation of the table shown in FIGURE 2 taken from the discharge end;

FIGURE 4 is a plan view of the table shown in FIG- URE 2;

FIGURE 5 is an end elevation, partially in section, taken along line 5-5 of FIGURE 4;

FIGURE 6 is an exploded perspective view of the side tilt adjusting means of the present invention;

FIGURE 7 is a view in side elevation of the side tilt adjusting means shown in FIGURE 6;

FIGURE 8 is a plan view of the side tilt adjusting means shown in FIGURES 6 and 7; and

FIGURE 9 is a sectional view taken along line 9-9 of FIGURE 2.

Referring now to FIGURE 1 of the drawings, the invention is illustrated in the form of an embodiment having three reciprocable decks 1, 2 and 3, each provided with a feed box 4 and a wash water launder 5 of the conventional type, but seen only on deck 1 in FIGURE 1. The feed boxes and wash water launders are located along the high side of each of the decks. In the form shown, each deck is provided with a headboard 6 which extends, to a slight extent, about the corner opposite the feed box, as shown at 7. The foreground corner 8 of deck 1 is denominated the middling corner. Between the middling corner 8 and the extension 7 of headboard 6 is the so-called discharge side 9, where the surface of the deck bevels downwardly outside the riffled area It) so as to overhang the open tops of collection launders such as 11 for deck 1, 12 for deck 2, and 13 for deck 3. Beyond the end of the wash water launder 5, all decks are provided with a sideboard extension 14 (seen only on deck 1 in FIGURE 1). Between the terminus of extension 14- and middling corner 8 is the discharge end 15, where the surface of the deck bevels downwardly so as to overhang the open tops of collection launders such as 16 for deck 1, 26 for deck 2, and 36 for deck 3. The rifiles in the rifiled area may be constructed and arranged in-any desired manner which is appropriate for the intended use of the concentrating table, as well understood by those skilled in the art, and indeed, in some instances, the decks need not be riffied. The deck 1, as thus described, is well known in the art, and the invention is not limited to decks of the particular construction. In the embodiment illustrated, wherein all decks are intended to be supplied With raw material of the same consist, the decks 1, 2 and 3 are duplicates of each other, but in cases where they consist of the feed for one deck may differ from that of another, the decks may differ in detail as to rifiling.

The collection launders 11, 12, 13, 16, 26, and 36 are likewise of conventional construction, but may, if desired, differ. The several collection launders are fixedly supported from a floor or suitable under-structure by columns 17, 18, and 19 in the conventional manner, so as to be entirely independent of the required movement of the decks.

In contrast to the fixed support for the several collection launders, the several decks are pendantly supported for collective reciprocating movement, and otherwise mounted for occasional collective adjustment relative to fixed structures and occasional individual adjustment relative to each other. The reciprocating movement of the several decks is induced by any suitable head motion device, preferably of the type which inherently generates substantially horizontal reciprocatory motion that is characterized by quicker reversal at one end of the stroke than at the other. One form of such a head motion device is disclosed in the aforesaid United States Patent No. 3,075,644, and is suitable for use with this invention. Such a head motion device 25 may be pendantly supported from an overhead structure in the manner shown in said Belgian patent, but is preferably supported from an overhead structure 27 by means of two pair of cables 28. The deck assembly is also supported, in part, by cables 28 and in part from an overhead structure 29 and a cable 30 at the discharge end of the table, as shown in FIGURE 2. The yoke 33 is fixedly secured at 34 to head motion 25, and is pivotally secured by pin 21 to deck 1, by pin 22 to deck 2, and by pin 23 to deck 3.

The several decks are adjustable for end elevation individually and collectively about their corresponding pivot pins 21, 22 and 23. Such collective adjustment is accomplishable by manipulation of turn-buckle 39 in cable 30; and such individual adjustment in end elevation is accomplishable by manipulation of adjusting screws 40, 41 and 42 on yoke bar 35, as described in the aforesaid Belgian patent.

The mechanism for accomplishing adjustment in side tilt of the individual decks is actuated by handwheel 43 for deck 1, 44 for deck 2, and 45 for deck 3. Manipulation of the respective handwheels produces limited rotation of the corresponding deck about a substantially horizontal axis perpendicular to the axes of pins 21, 22 and 23, respectively, and lying midway between the ends of those pins, as will now be described with reference to FIGURES 6, 7, 8 and 9.

As the side tilt adjusting mechanism associated with the respective handwheels are of identical construction, that associated with deck 3 will be taken for illustration. The shaft 46 of handwheel 45 passes through a lug 47, which is a part of bracket 48, rigidly connected to the yoke 33 at the level of deck 3. Shaft 46 is secured against axial movement relative to lug 47, as by means of collars 50 and 51 attached to the shaft on opposite sides of the lug. Within lug 47, shaft 46 is journalled by a bearing, preferably of the ball and socket type well known in the art, so as to permit limited angular displacement of shaft 46 about an axis designated as xx in FIGURE 6. On the opposite side of lug 47 from handwheel 45, shaft 46 is provided with a lead screw 52 which meshes Within complemental threads on the interior of block 53. Consequently, when block 53 is held against rotation, rotation of handwheel 45 results in movement of block 53 toward and away from lug 47, depending upon the sense of the rotation.

Block 53 is provided with a crank-pin 54, the outer end of which is received within a socket 55 in the lower end of a lug 56, which forms a part of bracket 57, which latter is fixedly secured to the sub-frame 49 of deck 3, .as shown clearly in FIGURE 2.

As shown in FIGURE 6, bracket 57 is also provided with a lug 58 corresponding to lug 56 (save that lug 58 has no socket such as 55), and the two are spaced apart for a distance more than sufficient to accommodate between them a lug 59 on bracket 48 within which is mounted the swivel bearing structure for pin 23. Pin 23 is in turn connected to lugs 56 and 58 by saddle members 60 and 61, respectively. Accordingly, when pin 54 is moved toward or away from lug 47 by rotation of handwheel 45, the deck sub-frarne 49 is driven in limited rotation about axis yy relative to pin 23, and parts 56, 57, 58, 60 and 61 which engage it, thereby increasing or decreasing (depending upon the sense in which handwheel 45 is rotated) the degree of side tilt of deck 3.

While, in the embodiment shown in FIGURE 6, bracket 57 and its adjunct parts are secured to the subframe 49 of the deck, and bracket 48, with its adjunct parts, is secured to the yoke 33, it will be understood that bracket 57 may, if desired, be secured to the yoke and bracket 48 secured to the sub-frame, as desired, without affecting the mode of operation of the parts. In either event, the reciprocating thrust generated by head motion 25 is transmitted by pin 23 from yoke 33 to the sub-frame of the corresponding deck. The structure of the swivel bearing on pin 23 which permits the aforesaid limited rotation about axis y-y (shown in FIGURE 8) is more fully depicted in FIGURE 9 of the drawings. Pin 23 has an enlarged central section 64, upon the exterior of which is mounted a ball sleeve 65 whose interior surface is cylindrical, but whose exterior surface is a doubly truncated sphere. About sleeve 65, there is a ring 66 whose interior surface is substantially contrageneric to the exterior spherical portion of the surface of sleeve 65, and whose exterior surface is substantially cylindrical, or otherwise shaped so as to fit within opening 67 in lug 59. On either side of lug 59, between it and lugs 56 and 58, there is one of a pair of resilient washers 68, which, while acting as a lubricant seal, permits limited rotation of lug 59 relative to lugs 56 and 58, as illustrated by the dotted lines in FIGURE 9. In order to compensate for wear between ball 65 and ring 66, the latter may be cut through radially at one side so as to leave a gap about a saW-kerf wide; as cut 62 made in lug 59, so that upon tightening a cap screw 63, the cut gap in ring 66 may be contracted.

With a table whose end elevation adjustment facilities are of the type wherein pivotal movement about the axis of pins 21, 22 or 23 is undesirable, such movement may be prevented by any suitable expedient, such as pinning the parts of 64 and 65 together in a manner which does not interfere with limited pivotal movement about the axis yy to vary side tilt. Regardless of whether the end elevation adjusting facilities are of the character just mentioned or that shown in FIGURE 2, the saddles 60 and 61 are preferably drawn down tight or otherwise equipped so as to restrain rotation of the pins 21, 22 and 23 relative to their respective lugs 56 and 58.

Hinging (about the axes of pins 21, 22 and 23) of brackets 57 which attach to the yoke 33 relative to the respective decks during normal operation may sometimes contribute to the introduction of vibration, or other secondary motion in remote portions of the decks. To stabilize the deck against such vibrations and secondary motion in structures such as that shown in FIGURE 2, where during normal operation there is continual vibrating action, the invention contemplates means for vertically biasing the portions of the respective decks most remote from their points of suspension. In the form shown in FIGURES 2, 3, 4 and 5, the areas of the deck most remote from their points of suspension are the middling corners 69, and the feed box corners 70. The dampening of secondary motion and vibration in the decks is most important at middling corners 69 when the table is being used for ore dressing. However, secondary motion at the feed box corners 70, while exerting remote, or no direct, effect upon the ore dressing operation, may, and sometimes does, induce secondary motion in those areas of the table where separation of the value from the gangue or tailings is actively taking place. Consequently, in the embodiment shown in the drawings, the vertical biasing means is applied at both the middling corners and at the feed box corners of the several decks, it being understood that the latter may, in many instances, be eliminated without adversely affecting the operation.

In the embodiment shown in the drawings, the vertical biasing means takes the form of weights of suflicient magnitude to strain the deck structure in one vertical direction, to a degree such as to resist the vibration and secondary forces which tend to move the deck in the opposite vertical direction. As illustrated, this result is accomplished by connecting, at the middling corner of the sub-frame of each deck, a cable 71 for deck 1, 72 for deck 2, and 73 for deck 3. The respective cables are trained over sheaves 74 for cable 71, 75 for cable 72, and 76 for cable 73. The respective sheaves have their axes fixedly mounted upon super-structure 29. The upper ends of the respective cables, after passing over their corresponding sheave, are connected to weights 77 for cable 71, 78 for cable 72, and 79 for cable 73. The Weights 77, 78 and 79 are not necessarily of the same finite magnitude, it being understood, as mentioned before, that the vibration characteristics of two decks are seldom identical. Accordingly, the magnitude of each of the weights is determined in practice by trial and error so as to counterbalance, as near as practical, the forces which tend to induce vibration or secondary motion. The arrangement of sheaves and weights is desirably such that, in normal operation of the table, no cable collides with another, and no cable collides with a weight; and the weights are sufficiently spaced, as shown, that they do not collide one with the other during operation.

As shown in FIGURES 2 and 5, a similar arrangement is mounted at the feed box corner, where cable 81 extends from the sub-frame of deck 1, cable 82 extends from the sub-frame of deck 2, and cable 83 extends from the sub-frame of deck 3. Each of these cables extends upwardly over a sheave 84 for deck 1, 85 for deck 2, and 86 for deck 3. The respective sheaves have their axes mounted upon super-structure 27. After passing upwardly over their respective sheaves, the downward reach of the respective cables is connected to a weight 87 for cable 81, 88 for cable 82, and 89 for cable 83. In this instance, as before, the magnitude of the respective weights is determined according to the idiosyncrasies of the deck with which it is associated, and, by trial and error, is adjusted so as to counterbalance forces which tend to induce vibration or secondary motion.

When and if desired, the respective weights 77, 78 and 79 may be surrounded by a protective basket, such as 90, supported by a bracket 91 from super-structure 29.

Thus, irrespective of the manner in which the decks and head motion are pendantly mounted, or the manner in which end elevation is accomplished, each individual deck is stabilized against vibrations and unwanted secondary movement by the attachment of vibration dampening weights to at least one, and preferably both, of the corners which are most subject thereto because they are farthest from the pendant supports. Likewise, in each embodiment, the vibration damper consists of cables extending from each deck over a fixedly mounted sheave, and provided with a counterweight of sufficient magnitude to maintain the flexible cable in tension and exert an upward bias on the corner of the deck sufficient to overcome the tendency for those corners of the deck to vibrate in the vertical direction.

From the foregoing description, those skilled in the art will readily understand that the invention accomplishes its objects, and provides a multiple-deck pendant- 1y supported concentrating table wherein the respective decks are stabilized against unwanted motion without impairing their freedom for individual adjustment in side tilt during operation of the device, or introducing lost motion into the reciprocating action. While one complete embodiment of the side tilt adjusting mechanism and the vibration damper arrangement has been disclosed in detail and explained in connection with two different forms of table mounting, it is not to be understood that the in vention is limited to the details of the foregoing disclosure, but, on the contrary, that the principles of the invention may be embodied in other forms and applied to pendantly supported tables which differ in detail from those disclosed, all without departing from the spirit of the invention or the scope of the appended claims.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:

1. In a multiple-deck pendantly supported concentrating table of the character in which the reciprocating motion is generated by a pendantly supported head motion of the polyeccentric flywheel type having quicker reversal of thrust at one end of its stroke than at the other end, the improvement which comprises, each deck having, independently of other decks, a flexible cable extending substantially vertical from its corner most remote from the head motion and movable means for exerting an upward force on said flexible cable.

2. The improvement of claim 1 wherein the movable means is a sheave over which the flexible cable is trained and a counterweight connected to the cable on the opposite side of said sheave from the cables connection with its deck.

3. In a multiple-deck pendantly supported concentrating table having a head motion of the character which generates reciprocating motion and means for connecting the head motion to the respective decks, the improvement which comprises, means providing a pivot axis between each deck and the head motion, said pivot axis extending generally parallel to the direction of said reicprocating motion, adjusting means adjacent each of said pivotal axes, said adjusting means having a first connection fixed relative to said deck and a second connection fixed relative to said head motion, and means between said connections for varying the distance therebetween, said lastnamed means being offset from said pivot axis.

4. In a multiple-deck concentrating table having a head motion of the character which generates reciprocating motion wherein the reversal is quicker at one end of the stroke than at the other end, said head motion having a yoke rigidly attached thereto, and said yoke having separate pivot connections with the respective decks, the improvement which comprises, adjusting means adjacent each of said pivotal connections but offset from the axes thereof respectively, said means having one end connected in force-transmitting relation with said yoke and its other end connected in force-transmitting relation with said deck.

5. The improvement of claim 4 wherein said adjusting means includes a lead screw and a threaded follower, one of said screw and follower parts being secured against movement axially thereof relative to said yoke, and the other of said male and female parts being secured against movement axially thereof relative to said deck.

6. In a pendantly supported multiple-deck concentrating table having a pendantly supported head motion of the polyeccentric flywheel type characterized by quicker reversal of thrust at one end of its stroke than at the other end and means for transmitting said thrust to reciprocate 7 said decks concurrently, the improvement which comprises, each deck being connected to said head motion by means including a pivot axis extending generally parallel to the direction of the reciprocating motion, adjusting means adjacent each of said pivot axes connected to the respective decks in offset relationship to its corresponding axis, said adjusting means being also connected to said head motion and having a lead screw and threaded followers in extensible and contractible relationship between said connections, each deck having at diagonally opposite corners thereof a flexible cable extending upwardly over a sheave mounted on an immovable axis, a separate counterweight connected to each of said cables on the 8 opposite side of its corresponding sheave from the portion thereof connected with the deck, said counterweights being respectively of a magnitude such as to maintain their corresponding flexible cables under constant tension and their corresponding deck corners under strain resisting the tension of said cables.

References Cited by the Examiner UNITED STATES PATENTS FRANK W. LUTTER, Primary Examiner.

Claims (1)

1. IN A MULTIPLE-DECK PENDANTLY SUPPORTED CONCENTRATING TABLE OF THE CHARACTER IN WHICH THE RECIPROCATING MOTION IS GENERATED BY A PENDANTLY SUPPORTED HEAD MOTION OF THE POLYECCENTRIC FLYWHEEL TYPE HAVING QUICKER REVERSAL OF THRUST AT ONE END OF ITS STROKE THAN AT THE OTHER END, THE IMPROVEMENT WHICH COMPRISES, EACH DECK HAVING, INDEPENDENTLY OF OTHER DECKS, A FLEXIBLE CABLE EXTENDING SUBSTANTIALLY VERTICAL FROM ITS CORNER MOST REMOTE FROM THE HEAD MOTION AND MOVABLE MEANS FOR EXERTING AN UPWARD FORCE ON SAID FLEXIBLE CABLE.

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