US2947187A - Apparatus for the rotation of drums - Google Patents

Description

Aug. 2, 1960 A. R. GRAFF ETAL APPARATUS FOR THE Ro'rATIoN oF DRUMS 3 Sheets-Sheet 1 Filed March l5, 1957 Aug. 2, 1960 A. R. GRAFF HAL APPARATUS FOR THE RoTATIoN 0F DRUMS 3 Sheets-Sheet 2 Filed Mrch l5, 1957 AUS- 2, 1960 A. R. GRAFF l-:TAL 2,947,187

APPARATUS FOR THE RoTATIoN oF DRUMS F' d h 11e Marc 15, 1957 35h96@ 2,947,187- l e APPARATUS Fon THE RorATIoN oF DRUMS Alan R. Grafi, Flossmoor, Ill., and Gordon O. Garis, Golden'Valley, and Robert L. Butts, Brooklyn Park, Minn., and Edwin C. Juergens, Chicago, Ill., assignors to The Columbia Malting Company, Chicago, Ill., a corporation of Illinois Filed Mar. 15, 1957, Ser. No. 646,406

Claims. (Cl. 74-142) and heavy and they may contain loads of heavy materiah As the drum is rotated the contents present an unbalanced load, piling up on the rising side of the drum and sliding back toward the low side. This movement may not be continuous and may impart severe shocks. to the drum rotating mechanism. Worm and gear drives have been used and also chain drives, but they have been difficult to maintain when handling the larger and heavier rotating drums. The present invention is especially adapted for use with such heavy drums carrying large loadsv of wet or damp malting grain, but itmay be advantageously used with any type of rotating drum.

The present invention comprises aA ratchet step by stepA v drive which is hydraulically operated.` The drive is positively connected to the drum and means are provided for cushioning and limiting slip-back ofthe drum.

It is an object of the present invention to provide a new and improved drive for rotating drums or the like.

lt is' a further object to provide a construction of this character designed to handle heavy unbalanced loads.

It is an additional object to provide such a drive including hydraulic operating means and spring cushioned holding means. r t

lt is also an object to provide a construction in which the ratchet and holding means have a permanent connection to the drum to be rotated, the connection permitting the drum to rotate relative to the operating and holding means.

It is another object to provide a construction includ?v ing holding means having a plurality of spaced holding elements so as to closely limit slip-back when the operat` ing thrust is released.

` An additional object is to'provide a power actuated piston yoke to which is pivotally connected a thrust barfor contact with the teeth of the rack for effecting intermittent rotation of the drum, Iand wherein the pivoted thrust bar has pulling action on the rack teeth, the said action together with the'pivot pins helping to maintain the structure in associated relation with the rack and to mainsimple in design and construction and adapted for com-y mercial production and use.

f Another object of the invention resides in the provisiony of separate and independent power cylinders for rotating drums` and the like and which are operated in an alternate manner and so arranged with respect to the peripheral rack onthe drum as toimpartcontinuous rotation to the'` drum -in-`the same direction.

Other and further objects willV appear asfthedescrip-,l

tion proceeds.

nited States` Piltfef f been enlarged to better illustrate constructional details;

We have shown a preferred embodiment of our invention in the accompanying drawings, in which Figure lis a fragmentary side elevation showing the apparatus applied to a drum;

Figure 2 is a fragmentary section taken on line 2 2 of Figure 1; i

Figure 3 is a fragmentary section taken on line 3 of Figure l; Y

Figure 4-is a fragmentary view of the spaced holding means Vfor limiting slip-back of the drum and which hasl Figure 5 is a sectional view of the rack;

Figure 6 is a sectional View taken alongline 6 6 of Figure 1 and showing the pivoted levers and thrust bar construction; and

Figure 7 is a fragmentary side elevation showing a modification of the invention which employs two power cylinders for continuously rotating the drum.

Inthe drawing, a portion of a drum has been shown at 11 with a circular rack 13 permanently and rigidly secured to its outer circumference. This rack as shown is made up of sections which may be riveted to the drum, or otherwise secured thereto. The drum is mechanically rotated in a clock-wise direction, and theteeth 15 of the rack have steep faces 17 against which the operating a mechanism thrusts. The teeth have sloping faces 19 over which the mechanism rides during the reverse movement ofthe mechanism.

The thrust mechanism comprises an hydrauliccylinder 21,- which, as shown, is double acting, fluid inlet and outlet pipes 23 and 2S being connected to its 'opposite ends. The cylinder 21 is pivotally supported by a pin. 27 bearing in abracket 28 secured to the floor or other serves to move ayoke 33, thearms 34 of which are spaced sufficiently so that they extend on opposite sides of the rack 13. The arms ofyoke 33, as seen in Figures 1 and 6, carrypivot pins 35 on which are pivoted thelevers 37. Thethrust bar 39 is carried between thelevers 37, this bar being adapted to thrustagainst the abrupt faces 17 of therack teeth 15. Thelevers 37 are connected by an oppositely extending arm 4'1 and which is joined by atension spring 43 to abracket 45 carried by theyoke 33. lt will be apparent that the tension spring '43 by pulling againstarm 41 urges thethrust bar 39 against the. rack 13. The rack 13 is', provided on each side with a circumferentially extending groove S47' proper relation'to the rack.

The holding mechanism is shown in the lower portion of Figure 1 and in the enlarged fragmentary `view of 63 which bears against one end of a compression spring;l

Figure 4. A pull bar 51 is pivotally connected at 53 tof a yoke 55. The spring pull rod 57 passes through the cross portion of yoke 55 and is held in adjusted position by nut 59. The head 61 of rod 57 carries athrust washer 65. Thisspring 65 surrounds the rod 57 and its opposite end ,bears against a dependingportion 67 of abracket 69 .which is permanently and xedlysecured to the base structure. Y V l The pull bar 51 is pivotally connected by pins 71 to4 the.arcuate bars 73 which carry the hold-back mechi anism. The yoke 75 is actuated a welded-in cross membei' for thearcuate bars 73, The pins71 extend into` thecircumferential grooves 47 and the said cross members are thus maintained in' proper relation on the rack. I -Ad'-ditional yokes 76, substantiallyidentical in constructionV to yoke 75, are provided as supportingvmeans for the hold-back mechanism andf whichrnaintain the holdingf means of saidmechanism, in proper'relation,l withV the teeth of the rack. Each yoke isa built-up structure-es# Patented Aug. 2, ,196()v4 sentially including atransverse bottom member 77, a pair of 'spaced exterior andinterior side walls 78 and 80, respectively, suitably welded to the bottom member and wherein the interior walls are inrturn welded to thearcuate bars 73; Each pair of spaced exterior and interior walls is closed at the left end of the end wall; member 81. Bac-hofV theyokes 76 has associated therewith a pair oflinks 82 having location between the respective exteriorandinterior side walls 78 and 80 of the yoke andA said links are pivotally connected to its yoke and to thearcuate bars 73 by theypivotpins 83 which additionally extend into thegrooves 47 formed in the rack member, as best shown in Figures-2 and 3. Hold-back crossbars join the links and for individual designation the cross bars for the three yokes carry the numeralsv 85, 86 and S7. .Each yoke also carries a atspring 90 suitably fixed to thebottom member 77 of its respective yoke by the screws 91A and at its free end; the spring has resilient contact with the cross bar either 85, 86orl 87 of its yoke. It will be apparent therefore that thesprings 90 serve to resiliently urge the hold-back cross bars into engagementwith the teeth of the rack 13. The spacing of the three cross bars is such that the drum and rack can neverV move in the counter-clockwise direction more than one-third, of` the space between adjacent teeth.

1n the operation of the apparatus, the hydraulic cylinder 21 has fluid under pressure applied to its lower end throughpipe 25, the piston and piston rod thus forcing theyoke 33 upwardly. Thethrust bar 39 thrusts against the-adjacent face 17 of atooth 15 to move the whole drum in the clockwise direction a distance determined by the length of movement of the piston in cylinder 21. During this rotation of the drum, thecross bars 85, 86 and 87 ride over theteeth 15, being held against the teeth by thesprings 90 and snapping down against thersteep face 17 of each tooth as the cross bar passes overV it. After the movement has been completed by the completion of the thrust stroke from cylinder 21, the pistonis retracted by releasing iluid throughpipe 25. If a` double-acting cylinder is used, uid will be forced in through pipe 23.

Assoonas thepin 39 moves away from thetooth 15 against which. it has thrust, there willbe a tendency for the drum torotate in the counter clockwise direction. This isdue to the fact that any loose contents of the drumwill tend to be carried upto the left side as seen inFigure 1, by the rotation of the drum and this side will therefore be heavier. This counter rotation of the drum is stopped quickly, however, by one of the hold-back cross bars, either 85,86or 87, whichever isclosest to the steep-face 17 of a tooth. The jar or shock of this stopping will be cushioned by thespring 65 and due to the spacing of the cross bars the travel can only befor a short distance.

Cushioning of this backward movement can also be accomplished or assisted by providing a restricted ow forthe hydraulic fluid leaving the under side of the piston in. cylinder 21 when theyoke 33 is being retracted for another stroke. This restriction in flow need only be eiective for a retraction distance of less than one tooth, in,- view of the spacing of Ithe hold-back cross bars 85, 86 `and 87.

The pivoted levers 37 and thethrust bar 39 constitute a structural combination which is of considerable importance to the invention and which materially adds to itssuccessful operation. If the pivoted levers and. thrust harv were not employed, then a relatively heavy spring wouldL haveto be applied to the upper endof the. cylinder 2.1 to hold thepiston yoke 33 in contact with the teeth of the rack. Such structure would be unsatisfactory` in operation sincea heavy spring would. produce bending stresses-in the piston yoke. Also. the massv of parts would be such as to prevent rapid movement. Thelevers 37 and-thrust bar 39 are relatively light in weight andtso'they move'v rapidly, whichis desirable for riding over and latching with the teeth of the rack. Further, the size of the spring that is required is materially reduced as a small light spring will hold the thrust bar in operative relation with the teeth and in addition the pivot pins 35 for the levers serve a dual function as they ride in thegrooves 47 `and soemaintain the piston yoke in proper associated relation with the rack.

Inthe-modication of Figure 7 the drum 111-is provided with a circular rack 113 permanently and rigidly secured tothe outer periphery. of the drum and which is preferably made up of sections, each section having -teeth 115. Said teeth, aspreviously described in connection with Figure l, have thesteep faces 117 against which theoperating mechanism thrusts and said teeth also have the sloping faces 119 over which the mechanism rides during the reverse movement of the same.

In this modification the drum 111 is continuously rotated in a clockwise direction and accordingly the holdback mechanism may be employed or the same may be eliminated. Iny order to illustrate the two power cylinders to the best advantage, Figure 7 does not show the holdback mechanism. In place of one operating power cylinderand said hold-back mechanism the drive mechanism for the drum consists of two power cylinders which operate alternately-and which are so related with the peripheral rack of the drum as to produce continuous rotation thereof' in the same direction, as, for example, in a clockwise direction, as illustrated-in-Figure 7. Thehydraulic power cylinder 121 is double-acting, havingpipes 123 and 125 at respective ends for they inlet and outlet of a pressure uid, to thus eect reciprocation of the piston, not shown, and which accordingly produces similar movement of the yoke 13-3. Thecylinder 121 is pivotally supported bypin 127 inbracket 128; preferably secured to the oor or similar supportingstructure 131, The yoke is bifurcated at its upper end to provide a pair ofarms 134, Figure 6,V and which arms carry the pivot pins 135. In accordance with the invention,` the pivot pins pivotally secure thelevers 137 in place and said pins project within thecircumferentially extending groove 147 to thus retain the yoke andthe assembled parts in proper relation with respect to the rack. The connecting arm 141 is joined by coil spring'143'to the brackct'14-5 and in this manner thethrustbar 139,v provided by thelevers 137, is resilient maintained in operative contact with the teeth of the rack. The second power cylinder is identified bynumeral 151 and the same is likewise double-acting, being provided withpipes 153 and 155 at respective ends for the inlet and outlet of a pressure fluid to thus actuate the piston of the cylinder and impart reciprocating movement toyoke 163; Thecylinder 151 is pivotally connected by the pin 157 to a bracket 158 which may be suitably supported by thestructure 131. Theyoke 163 is bifurcated at its upper end to provide a pair of spacedarms 164 similar in all respects to the spacedarms 34, as shown in Figure 6. Likewise, said arms pivotally support the levers 167 by means of thepins 165, and said levers carry thethrust bar 169 for contact with the teeth of the rack. The levers 167 are resiliently biased by thecoil spring 173 and this maintains thethrust bar 169 in contact with the teeth of the rack. Said coil spring is secured at one end to the lever connecting arm 171 and at its opposite end to thebracket 175. Also said pins ride within thecircumferential groove 147.

Thecylinders 121 and 151 alternate as regards their power strokes so that when one cylinder is operative to produce' rotation of the drum 111, the other cylinder is retracting its yoke to its initial position. As shown in Figure 7, it will be observed that thesecond power cylinder 151 has about completed an operative stroke in' an outward direction toward the left, thus effecting rotation of the drum 111 in a clockwise direction. Thethrust bar 169 is in contact with the steep faces 117 of the rack and with the pivot pins 165, having location within thecircumferential groove 147, a pullY is exerted on the thrust bar which is approximately a straight line pull due to the particular angular relation which the power cylinder has with this bottom side of the drum. When the second cylinder -1 completes its operative stroke, therst power cylinder 121 will be ready for its operative outward stroke. Here again a pulling action is exerted by thethrust bar 139 on the teeth of the rack and the clockwise rotation of the drum 111 is continued.

The power cylinders accordingly operate intermittently to produce continuous rotation of the drum and while to locate its yoke and thrust bar in a retracted position so that movement can be again effected in a directiontoward the left, the same constituting an operative stroke for this cylinder.

Whereas, cylinder `121 has' a power stroke in an outward and upward direction, thesecond cylinder 151 has a power stroke in an outward direction to the left. This, of course, comes about by reason of the particular relation which the cylinders have with the circumferential rack of the drum, one being located adjacent the left side of the drum and the other adjacent the underside of the drum. For effecting 'the same continuous rotation of the drum in a clockwise `direction both cylinders could be located for coaction with the bottom of the circumferential rack or for coaction with the rack at the left side, or at the right side of the drum.

The apparatus shown is to be understood to be illustrative only as it is capable of variation to meet differing l and each tooth being uniformly spaced from adjacent teeth and having a steep face and an inclined face, power means for rotating the drum including a yoke adapted to reciprocate for producing a power stroke and a return stroke, a pivot pin provided by the yoke, a thrust bar suspended from the yoke by levers which are pivotally connected to the yoke by said pivot pin, said thrust bar having operation to engage the steep face of a tooth during a power stroke whereby to effect rotation of the drum and to ride over the inclined faces of the teeth when the reciprocating yoke is retracted, said rack having a circumferential groove formed in a latheral face thereof, said pivot pin extending into the groove whereby to maintain the yoke permanently connected to the rack throughout the rotation of the rack and drum, and hold back 6 relation, a pair of levers suspended lby the pins, a thrust bar fixed to and connecting the levers, said thrust bar having operation to engage the steep face of a tooth during a power stroke whereby to effect rotation of the drum and to ride over the inclined faces of the teeth when the reciprocating yoke is retracted, said rack having a circumferential groove on each lateral face thereof, each pivot pin extending into a groove whereby to maintain the yoke permanently connected to the rack throughout the rotation of the rack and drum, and hold back means in operative association with the rack, said means comprising a plurality of bars each pivotally connected to a supporting member and disposed transversely of the rack, whereby the bars are adapted to engage the teeth thereof to limit reverse movement of the drum during the return stroke of the' yoke, said bars being spaced -apart so that the drum never moves in a reverse direction more than means in operative association with the rack and adapted about one-third of the length of a tooth.

3. Apparatus for the rotation of drums as defined byv `rack secured to the drum and extending circumferentially around the drum, said rack having teeth formed thereon yand each tooth having a steep face and an inclined face,l power means including a yoke adapted. to reciprocate for producing a power stroke and a return stroke, said yoke providing a pair of spaced arms, a pivot pin xed to each arm, a lever disposed inside the yoke adjacent each ann and :being pivotally connected thereto by a pivot pin, a thrust bar xed to and connecting the levers, said rack having a circumferential groove on each lateral face thereof, each pivot pin extending into a groove whereby to maintain the yoke permanently connected to the rack in a manner permitting rotation of the rack and drum and whereby the thrust bar is disposed transversely of the rack, and resilient means maintaining the thrust bar in contact with the teeth of the rack, whereby the thrust bar has operation to engage the steep face of a tooth during a power stroke to elfect rotation of the rack and thus the drum and to ride over the inclined faces of the teeth when the reciprocating yoke is retracted.

`5. Apparatus for the rotation of drums as defined by claim 4, additionally including hold back means in operative association with the rack, said means comprising -a plurality of bars each pivotally connected vto a supporting member and disposed transversely of the rack, whereby the bars are adapted to engage the teeth thereof to limit reverse movement of the drum during the return stroke of the yoke, and said bars being so spaced longitudinally of the rack that reverse movement of the drum is limited to less than the length of a tooth.

References Cited in the iile of this patent UNITED STATES PATENTS 379,656 Parish Mar. 2o, 188s 805,349 Knight Dee. 5, 1905 2,377,733 Waller June 5, 1945 2,487,733 Scheffer Nov. s, 1949 FOREIGN PATENTS 703,224 Great Britain Ian. 27, 1954

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