US2639903A - Torque converter for mixing drums - Google Patents

Description

May 26, 1953 R. J.. KAQENA 2,639,903

TORQUE CONVERTER FOR MIXING DRUMS Filed Dec. 21, 1951 INVENTOR.

BWM/0;.

Patented May 26, 1953 UNITED STATES PATENT OFFICE 4 Claims.

This invention relates in general to a` mixing drum `which is rotatable about a horizontal axis from one position to another, such as from a `load-receiving position wherein a door-equipped lateral opening is relatively high to a second position wherein the load is free for gravity discharge therefrom. Such a drum is cylindrical in form, with heads at opposite ends extending in parallel planes that are substantially vertical.

With a drum of this character there is provided |a power-driven shaft extending axially thereof and beyond its opposite ends to be rotatably supported in suitable bearings. This shaft carries a suitable stirring means to be advanced through the load of loose material and may take the form of a plurality of fixedly connected radial arms sup-porting a blade (or blades) which is extended lengthwise of the drum close to the inner face of its curved wall. In operation, the loose material within the drum is stirred, tumbled, displaced, and mixed by the advancing movement of the blade within the drum. At the conclusion of the mixing operation, it is usual to rotate the drum through the necessary distance for shifting its lateral opening to discharge position. 'I'he load is then free to fall out by gravity, assu-ming that the door is opened for this purpose.

No special problem is involved in providing for movement of the stirring means within the drum. However, when the loaded drum itself is to be turned to discharge position, it has not been possible heretofore to convert satisfactorily any of the torque developed from power operation of the stirring means to effective use in a controlled rotation of the drum itself. At present, in most of the mixing drums used in many industries, this rotation of the drum is performed by hand, and where heavy loads are involved this operation requires considerable effort on the part of the attendants.

It is a primary purpose of this invention to provide for mixing drums of the character described a torque convertor whereby the power employed for operation of the stirring means within the drum may also be utilized to establish a state of equilibrium therefor whereby, with a minimum of effort, the drum may be rotated, either direction, to or from any desired position, such, for example, as a dumping position where the lateral opening into the drum is disposed at a relatively low down point. The means for accomplishing this objective, as hereinafter disclosed in detail, are simple and inexpensive to produce and operate, and may be relied upon to facilitate and expedite the successive load treating operations for which the drum is designed.

A suggestive embodiment of this invention is illustrated in the accompanying drawing where- 1n:

Figure 1 is a longitudinal vertical section taken centrally through a vconventional mixing drum equipped With my improved torque convertor mechanism;

Fig. 2 is a semi-diagrammatic view in transverse section through the drum as it appears when rotated to the position wherein its lateral openingy is up, and Fig. 3 which is a similar View shows the drum rotated to a position wherein its lateral opening is down; and

. Fig. 4 is a vertical section, taken on line 4--4 of Fig. l.

As herein shown, a pair of spaced stands A upstand from a base B to support between them a horizontal shaft C which extends axially through a cylindrical drum D having closure heads I0 and I l at its opposite ends. A rotatable mounting for the drum is provided by a bushing l5 rotatably fitted over one end portion of the shaft and carried within a bearing IB that is rotatably supported in a collar Il having radially extended arms I8` that are connected by bolts I9 (or otherwise) to the drum head Ill, and by a bushing 20` rotatably fitted upon the opposite end portion of the shaft and rotatably supported within a collar 2l equipped with arms 23 that are extended outwardly for connection, as with bolts `24, to the drum head Il. The collar 2| is itself journaled for rotation in a two-part bearing 25 that is carried at the upper end of the proximate stand A.

The outer end of the collar carries a transversely disposed mounting plate 32 to which is affixed a housing E, and constituting therewith and with the drum D a unit that is mounted to swing about the axis of the shaft C. In the mounting plate and opposite wall 33 of the housing are journaled for rotation the opposite ends of an idler shaft 35 upon which is xedly carrieda pinion 36 and a gear 3l. This idler shaft is disposed with its axis eccentrically of the axis of the shaft C. The pinion 36 meshes with a gear 38 that is carried fast on the shaft C at a point close to its end, and the gear 31 is in mesh with a pinion 40 formed on a relatively high power-input shaft 4| one end of which is journaled in the housing wall 33 and extended therethrough to carry fast on its outer end portion a sprocket wheel 42. The opposite end of the input shaft 4| is journaled to rotate freely within an axial socket 43 in the end of the shaft C and in the same direction therewith. The axis of the input shaft 4I is concentric with that of the drum shaft C. An endless chain 45 runs over the sprocket wheel 42 and also over a similar wheel 4B on the shaft of a motor F that is mounted on the base B. When operated, power from the motor will be transmitted through the gear train to rotate the shaft C, the housing and transmission, together. with the drum to which the housing is rlxedly secured, tending to remain stationary therewith. Due to the preponderance of the housing weight being located well below the two coaxial shafts C and 4,1 (as, viewed Fig. 1), it may be desirable to position a weight 47 at the housing top to serve as a counter-balance therefor.

Fitted upon the shaft C within the drum at opposite ends thereof is a pair of cellars S0. equipped with sealing gaskets, and therebetween is.- carried; a stirring meansadsptsd to, be. moved through the loose material; in. response to rots.- ton ofV the shaft.- As stunts,` this meses-C9111- nrises a pair of spaced arms.- 51 that. are carried fast by the shaft and extended radially there,- from` to support between them a blade 52; which is disposed longitudinally of theV drum. at s.` pomt close to the inner face. of; its curved Wall. A further blade 53 may optionally be carried inwardly of the blade, 52 to be, supported therefromby an arm 5A. With each operation of the. shaft C. the blade. (or blades). is moved through a circular path within the drum to, stir, displace, orv mix the. loose. material therein that is to. be treated.

A lateral opening 5:1. is providedinthe curved wall of the drum and equipped, desired, with a door 58 having a suitable latch whereby to. provide. a closure. therefor. When. in the. position of Fig. 2, the. drumv will. receive` and retain its load of loose mate-rial to. be operated upon. by the stirring means, but when the drum is turned tothe position of Eig. 3 (or. further). its. con-.tents will be. gravity-discharged through. the opening. 51.

The material in the drum, when acted. upon bythe stirring means, offers. a resistance that is approximately equal to the friction obtaining between the material and the innen surface of the drum. A torsional force is therebyexerted on the drum substantially the same asA theforoe that is generatedv by the resistance of the. loose material to the movement of the stirring means therethrough. These two forces arealso exerted in the same direction. Since the. drum` D. and housing E are fixedlyinterconnected, this same torsional force. is transmited backA tol the housing as well, but in a direction opposite. to the frictional torque thatis transmitted tothe'hcusingthrough the. idler. shaft 35.. A condition of substantial equilibrium is thereby achieved, and the net result is to. neutralize. the resistance of the material in the. drum to` turning.. movement of the latter. The. drum may, accordingly. be manually rotated, or otherwise, with a minimum of effort, in either direction, and through one or more revolutions. This balancing. off forces continues irrespectiveof the amount of frictional torque generated in. the drum, due tothe resistance oiiered byv the. loose. material therein to movement of the. stirring means therethrough, Any variation in, such resistance (due tp different` densities, consistencies, volume, etdin the material) is. accompanied by. a corresponding change. in the amount, of. torque whose velue is approximately. equal thereto and opposite inits direction,I

The maintenance of a balanced condition in the forces present will for all practical purposes reduce to the zero point the eiiort involved in manually rotating the drum. However, in some cases it may be desirable to utilize a light auxiliary power means for this purpose. Such an arrangement is suggested in Fig. 1 where a sprocket wheel 6e is mounted fast on the collar Il, to be @leased by an endless thais, El. wbieh trained over` a sprocket wheel 62 that :is mounted free on the shaft 63 of an auxiliary motor G. A collar 6,4 that is splined on the shaft of this motor is shiftable in response to operation of a control lever (i as to engage or disengage the proximate end o f the sprocket Wheel 62. As by means of coaetingclutch teeth on the collar G4 and spl'keb Wheel SI2, power from the motor G is transmitted to the collar I1 thereby to revolve the-drum whenever the control lever 65 is operated to the proper position for this purpose. Due to thev stat-e of equilibrium that4 is maintained by the. means already described, the Vpower required forI rotation of theV drum to and from any desired position need be butv very smallperhaps one per cent of that of the motor Fl which operates the stirring means within the drum.

A mixing drum equipped with the present torque converter may be used. to advantage in various industries for operation upon different materials.. In the construction industry, for example. this would include mixers for concrete, plaster and theV like. Manifestly. the effort involved, in rotating a normally stationary loaded drum from one rotative position to another, either way and any distance, is reduced to a. minimum when the torque. converter of this invention is applied thereto.

I claim:

1. A torque converter mechanism of the kind described in which is combined a cylindrical drum having a horizontal axis and provided in one wall thereof with an opening through which loose material may pass intoY and out of the drum, an axial mounting at one end ofthe drum for rotatable support thereof, a collar iixedly secured to the opposite drum end, axially thereof, and extended outwardly therefrom, a shaft extending axially through the drum and through the collar for rotatable. support thereof, a bearing Wherein the. collar is rotatably supported, a housing xedly securedto. the outer end of the collar, a. transmission within the housing comprising a power-input shaft coaxiai with the drum shaft, an idler shaft mounted in said housing for bodily movement therewith and having its axis eccentrically of thev drum shaft axis, intermeshing gears and pinions carried by the input and idler shafts and by the drum shaft to establish a train of driving connections therebetween, arms xedly carried by the. drum shaft and extending laterally therefrom, and a blade supported by the arms. and disposed lengthwise of' the. drum. relatively -close to. the inner surface. of. its curved wall, the arrangement being such thatthe frictional torque on the. drum, occasioned by resistance. of the. loose materialy therewithin to. movement of the blade therethrough, will be transmitted back t20; the housing in an amount approximatelyV equal @that transmitted to the housing by the idler shaft, butin the` opposite direction, thereby to DlQdllQe substantially a, condition of' equilibrium permitting rotation of the drum in either direc, tion through 360'*- or` more. with a. minimum of COll 2.. A1 ,tor-.que convertor,y mechanism. of.- the kmo,

described in which is combined a cylindrical drum having a horizontal axis and provided in one wall thereof with an opening through which loose material may pass into and out of the drum, an axial mounting at one end of the drum for rotatable support thereof, a collar ixedly secured to the opposite drum end, axially thereof, and extended outwardly therefrom, a shaft eX- tended axially through the drum and collar for rotatable support thereof, a bearing wherein the collar is rotatably supported, a housing at the outer end of the collar and iixedly mounted to rotate with the drum, a transmission within the housing comprising a power-input shaft coaxial with the drum shaft, an idler shaft mounted in said housing for bodily movement therewith and having its axis eccentrically of the drum shaft axis, intermeshing gears and pinions carried by the input and idler shafts and by the drum shaft to establish a train of driving connections therebetween, and stirring means xedly carried by the drum shaft and extending away therefrom into engagement with loose material contained within the drum to be advanced therethrough when the shaft is rotated relative to the drum, the arrangement being such that the frictional torque on the drum, occasioned by resistance of the loose material therewithin to movement of the stirring means therethrough, will be transmitted back to the housing in an amount approximately equal to that transmitted to the housing by the idler shaft, but in the opposite direction, thereby to produce substantially a condition of equilibrium permitting rotation of the drum in either direction through 360 or more with a minimum of effort.

3. A torque convertor mechanism of the kind described in which is combined a cylindrical drum having a horizontal axis and provided in one wall thereof with an opening through which loose material malr pass into and out of the drum, axial mountings at opposite ends of the drum for rotatable support thereof, a shaft extending axially through the drum and rotatable relative thereto, a motor, a transmission iixedly carried at one end of the drum in ysubstantially balanced relation axially thereof and comprising two shafts, one having its axis concentric with the axis of the drum shaft and the Iother eccentric thereof, drivlng connections between (1) the concentric and eccentric shafts in the transmission, (2) the eccentric shaft and the drum, and (3) the concentric shaft and the motor, whereby to transmit power from the motor to the drum shaft for operation thereof, and stirring means carried by the drum shaft and extending away therefrom into engagement with the loose material contained within the drum to be advanced therethrough when the shaft is rotated relative to the drum, the arrangement being such that the frictional torque on the drum, occasioned by resistance of the loose material therewithin to movement of the stirring means therethrough, will be transmitted back to the housing in an amount approximately equal to that transmitted to the housing by the eccentric shaft, but in the opposite direction, thereby to produce substantially a condition of equilibrium permitting rotation of the drum in either direction through 360 or more with a minimum of effort.

4. Apparatus for mixing and agitating materials comprising, a mixing drum mounted for rotational movement to enable loading and unloading thereof through an opening therein, a rotatable blade-mounting shaft mounted coaxially with the drum for movement with respect to the drum, a blade secured to said shaft for agitating material in said drum and creating,` through the agitated material, a force which tends to rotate the drum, a power source for rotating said blade-mounting shaft, and mechanism for utilizing the torque on said drum to produce substantially a condition of equilibrium permitting rotation of the drum in either direction through 360 or more with a minimum of effort including, a housing secured to the drum for movement therewith and having therein a power input shaft coaxial with the blade-mounting shaft, an idler shaft mounted in said housing for bodily movement therewith and having its axis eccentrically of the blade-mounting shaft axis, intermeshing gears and pinions carried by the input and idler shafts and by the blade-mounting shaft to establish a train of driving connections therebetween.

RICHARD J. KACENA.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 443,410 Shambaugh Dec. 23, 1890 980,827 Osner Jan. 3, 1911 FOREIGN PATENTS Number Country Date 884,787 France Aug. 26, 1943

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