US2362435A - Concrete mixer - Google Patents

Description

Nov; 7, 1944.

L. G. HILKEMEIER CONCRETE MIXER wFiled. Jan. 28, 1942 2 Sheets-Sheet 1' Louis GHillremeier,

Patented Nov. 7, 1944 UNITED STATES l OFFICE I q 2,362,435 v CONCRETEMIXER Louis G. Hilkerneier, Milwaukee, .Wis., assignor to A Chain Belt Company, Milwaukee, Wis., a cor- .poration of.Wisconsin Application January 28, 1942, Serial No.428,603

4 Claims.

Patent N0..2,045,532, granted June 23, 1936, on,

an application filed by 'John C.- Merwin and Charles F. Ball. The present invention however, represents a further development of certain chargingmechanisms. devised by the-said Ball, .0

primarily for usein connection with the inclinedaxis type of machine disclosed. in'the aforesaid patent,,which mechanisms are fully set forth in U. S. Patents Nos. 2,265,751 andi2,265,752,geach granted December 9, 1941, and in U. S; Patent No. 2,281,820, grantedMay 5, 1942. 1

Briefly, the last mentioned patents and appli cation disclose a vcharging hopper structure for the open upper end of a rotatable inclined-axis mixing drum, said structurefincluding a non-rotatable hopper and being mounted for reciprocatory movements toward and from the drum opening upon I a shaft disposed axially of the drum and extending through its said opening to and through the rear inclined wall of the hopper. While in actual practice these constructions have been found quite eificient in the accomplishment of their intended purpose of rapidly inducting the concrete-making solids into. the drum, at the same time the extension of the supporting shaft to and through the rear wall, of the hopper, notwithstanding that its dimensions were nominal, impeded to some extent the flow of the materials down the inclined rear wall of thehopper toward which the materials naturally gravitate,

It is one of the principal objects of'the present invention, thereforato provide a charging hopper construction for a mixer of this type wherein the supporting shaft'doesnot extendto the rear inclined wall of, the hopper, thereby providing for theunobstructed passage of the mateing materials-thereto through the hopper, and it is a still further object 'ofthis invention to provide an improved ventinglmeans for that purpose. l y v t With the above and other objectsin view which will appear as the, description proceeds, the invention resides in the novel details of construc- Referring to the accompanying drawings form- ,ing apart ofthis specification, in which like reference characters designate lik parts in allthe Iviewsz' Figure 1 is a longitudinal vertical sectional vation and upon a' slightly larger scale, of the non-rotating hopper and axially movable with;

it to and from a position inwhich its perimetric portion engaged with the portion of. the drum surrounding the drumopening, inwhich position the said annulus rotated'with the drum; Itis a further object of the present invention to provide an improved bearing. and seal construction for this annular member.

The said Ball application Serial No. 354,521 further disclosed a venting arrangement for, the. hopper, providing for-the escape of air from the .drwn during the char in at th t m k parts shown in Figure 1, takenapproximately on looking in the direction of the arrows;

' Figure 3 is an elevational view of the hopper structure per se, partly broken away and without the intermediate annulus, as; seenfrom the left of Figure 1; 7

the plane indicatedbylthe line 22 of Figure 1,

Figure 4' is an'elevational view of the interme- .diate-annular member per se, as seen from the rightlnl igurekand v V I Figure'5 is an enlarged cross sectional view throughthe improved bearing and seal between the hopper structure and intermediate annulus.

Referring more particularly to the said drawings there is illustrated, for the purposes of the present disclosure but not by way of limitation, the rear end portion of; a mixingdru'mlfl, of a high-discharge truck-mounted concrete mixer of the type exemplified in the aforesaid patents,

-which drum. is mounted in a framework It for rotation about an axis inclined to the horizontal by any suitable well-known means, not shown.

The end of the drumisprovided with the material-transfer opening 12 which has associated with ita charging hopper structure, similar in certain respects to that disclosed in thesaid Ball patents and application, which structuremay-be mounted by the drum H! for reciprocating-movements in the direction of the drum axis to and from "said material-transfer opening l2. The

movements away from the drum or toward the right from the positions shown in'Figure 1, are

for the purpose of permitting discharge of the and gravel or crushed stone, through the opening l2 and into the drum where they will be transformed into the finished concrete mixture by the usual helical mixing blades IIJ upon rotation of the drum. In this position the hopper structure also prevents discharge of the materials through the opening 12 during mixing.

The advantages of mounting the hopper structure upon the drum rather than upon the supporting framework I may be readily appreciated since such mounting maintains a constant re; lationship between or alinement of the drum and hopper structure, whereas if the hopper were mounted upon the framework ll, distortion of such framework due to the twisting and weav-x ing movements of the truck chassis upon which the mixer unit is mounted, as it travels over rough ground, might misaline the drum and hopper to such an extent as to result in leakage of materials from the discharge opening during mixing and also possibly during charging, if the truck happened to be upon an uneven surfaceat that time.' 7

As here shown, the hopper structure comprises a non-rotatable hopper l3 of more or less inverted coniform shape, the forward portion l4 of the wall of which is provided with a discharge port 15 through which the materials introduced through the open top of the hopper may pass into the drum by way of the transfer opening 12 of the latter, as will be readily understood from Figure l. The opposite or rearward portion l6 of the hopper wall inclines sharply downwardly, substantially as shown in Figure 1, to the said discharge ,port 15 and since the action of gravity upon materials introduced into the hopper tends to cause such materials to seek and traverse this portion ofthe hopper wall, it is important from the standpoint of rapid charging of the materials into the drum that this portion of the wall be free from obstructions which would interfere with the movement of materials along it.

In order to provide a construction in which this rear wall is unobstructed and thus facilitate the charging of the materials, the present inven-' or bearing 20 which is supported by the drum' 10 as, for instance, by means of the radially extending rods or tubes 21 rigidly secured to portions of the helical mixing blades In, or directly to the shell of the drum, and to the said sleeve,

as will be readily understood. In the construction shown the shaft 19 is rigidly attached to the bracket l8 and since the hopper structure does not rotate, the said shaft is journal'ed in the sleeve 23 so that the drum may rotate around it. On the other hand the shaft is axially slidable within the said sleeve so that the hopper structure may be moved away from the drum, or toward the right, as viewed in Figure l, in

order to permit discharge of the mixture, and v subsequently return to the Figure 1 position to condition the apparatus for chargingand mixing, as is fully disclosed in said prior Ball patents.

It will be noted that the shaft I9 extends into the hopper structure only approximately to the discharge port l5 and its end is materially spaced from the inclined rear portion l6 of the hopper wall whereby it oifers no interference to materials. moving downwardly along said wall and into the drum. While the supporting bracket 18 blocks off a portion of the discharge port I5, such obstruction as may be'imposed thereby to flow of the materials through said port occurs in an upper segment of the latter rather than along the sloping rear or bottom wall l6 of the hopper to which the materials naturally gravitate; and the impediment to the materials occasioned by the bracket is offset by the advantage resulting from the creation of a void forward of the bracket through which air may pass to the air vent, as will appear more fully below. Furthermore, the said bracket may be so shaped and the use of the construction just described.

As above indicated the hopper I3 is non-rotatable, linkage 25 similar to that disclosed in the said Ball patents, Nos. 2,265,751 and 2,265,752, being provided between the hopper and frame H for preventing rotation while at the same time permitting reciprocation; and as in the said patents, the hopper element carries an intermediate ring member 26 journalled thereon for engagement with and rotation by the drum l0, when the parts are in the charging or mixing position illustrated in Figure 1. An annulus ll, of angular cross section, is rigidly carried by the collar H and one leg thereof conveniently forms one member of a journal bearing 36 for the ring member 26, the other or ring-carried member of which comprises an annulus 30, which is rigidly mounted upon the said ring member as by the bolts 3| and spacing bushings 32. A retaining ring 30', also secured by bolts 3|, serves to maintain the intermediate ring assembly 26, 26', 30 in operativeposition on the annulus H.

The annulus 30 is provided with an annular recess 33 (see Figure 5) in which any suitable packing or sealing material 34 may be positioned and held snug against the member [1' by suitable means such as a coil spring 35, whereby to provide a labyrinth seal forprotecting the hearing 36 against extraneous material. A grease fitting 31 may be provided, communicating through members I! and H with the said bearing, to supply lubricant thereto.

In order to further protect this hearing against the entry ofabrasive constituents of the concrete mixture thereto an additional seal is provided, comprising a resilient sealing ring 40, which is mounted upon the member 11', as will be clear from Figures 1 and 5. This sealing ring is pro vided with a plurality of outwardly extending circumferential .ribs or flanges 4| which are axially spaced from one another to provide an annular space 42 between them. These flanges are constructed to extend straight out from the base ring 40, as indicated by, broken lines of Figure 5,

but in the assembly of the parts, they are engaged of them in an outward direction, as by materials within the drum seeking to [work outwardly, merely forces them more firmly against the inner surface of the annulus 26' and any tendency of the concrete materials to work past them is-thus resisted very efiiciently. The space 42 between the ribs 4| is preferably filled with grease by means of a grease fitting 45 and pipe 45, communicating withthe said space, and the curved tensioned condition of the right hand flange 4| is likewise effective in resisting any tendency of such grease to work past it. Should there be any escape it would be towards the left as viewed in Figure 5, past the left hand flange4land into the drum.

In the said prior Ball application Serial No. 354,521 there was disclosed a means for venting the drum during charging, to prevent the building up of pressures therein during the charging operation. The present invention contemplates an improvement in this venting means, which as here shown, comprises a substantially rectangular shield 50 having side walls and a bottom wall, which shield is pivotally mounted as at 5| by a bracket 52 carried by the portion I4 of the hopper wall. This shield extends downwardly in front of the upper portion of the supporting bracket l8, its side and bottom walls being suitably conformed to the contour of the parts,'and the said bracket I8 is provided with a venting aperture 54 which affords communication betweenthe interior of the shield member 50 and the area forward of the said bracket where, as above indicated, a void is formed during charging. The upper end of the shield may be open as shown in Figure 1 and in addition thereto a vent opening 55 may be provided in the wall portion 14 V to accommodate escape of air from the drum in the event the open upper end of the shield should become clogged. By pivotally mounting the shield on the bracket 52 the shield may be readily swung backwards, or counter-clockwise as viewed in Figure l, for cleaning purposes should it'become clogged with cement dust or other materials, and upon release it will drop to its original position where it will be maintained by the materials as they pass through the hopper. The

non-rigid mounting of the shield also produces a tendency toward the automatic clearing of the vent through vibration of the parts when the machine is in use.

Any suitable means for reciprocating the hopper to and from its operative position may be prov port andhaving a bracket member within said hopper extending across said port from the pe-.

r the perimeter of said member to its axis, the invided, those here shown being similar to the means disclosed in the said Ball Patents Nos. 2,265,751 and 2,265,752 and including a manually operable shaft carrying a pair of operating arms Bl extending downwardly, one to either side of the hopper 13. The lower ends of these said arms are connected through resilient'or compressible connections 63 similar to those described in ing from the spirit of the invention and there- .fore it is not wished to be limited to the above disclosure except as may be required by the claims.

What is claimed is:

1. In a concrete mixer, means for mounting a non-rotatable charging hopper upon a rotatable concrete mixing drum for reciprocatory movements toward and from a material-transfer openingin one end of said drum, said hopper having a discharge port co-operatively registerable with said drum opening for the transfer of materials from the hopper into the drum: said hopper mounting means comprising a collar structure secured to the hopper 'around said rimeter to the axis of the latter; means carried by said collar structure whereby the collar and hopper may be moved toward and from the drum opening; a shaft for supporting said hopper having one end portion mounted in said bracket in substantially the plane of said hopper port and projecting therefrom axially through said drum opening; and a hearing within and rotatable with the drum, slidably supporting the projecting portion of said shaft for movements axially of the drum.

2. An element for mounting a charging hopper .upon a rotatable concrete mixing drum with the discharge port of the hopper in co-operative reciprocatable relation to a material-transfer opening in an end of the drum, said element comprising an annular member securable to the hopper surrounding its discharge port and having a substantially radial bracket an arm extending from ner end of said bracket arm being formed to receive a portion of a hopper-supporting shaft mounted bythe mixing drum axially of its transfer opening, said annular member also having oppositely disposed trunnions for connection to a hopper reciprocating means.

3. The combination with a charging hopper for Y concrete mixer drums, having a wall provided with, a discharge port through which the concrate-making materials pass into the drum, of a shield member non-rigidly mounted in the hopper adjacent said wall and extending into saidport sufiiciently to provide a channel for the escape of air therethrough during the occupancy of the remainder of the port by materials passing thrcl h said hopper, the non-rigid mounting of said shield member providing for its vibratory agitation during operation of the apparatus to tend to automatically clear the channel of materials which may enter and deposit therein.

4. In a charging hopper for concrete mixer drums, having a wall provided with a discharge port through which the materials pass to the drum, a hopper supporting member having an apertured portion disposed within the area'of said port; and means for venting the drum during charging comprising a shield member pivotally mounted adjacent said hopper wall, the upper portion thereof being in open communication with the atmosphere and the lower portion thereof embracing the aperture in said supporting member. l

LOUIS G. HILKEMEIER.

CERTIFICATE OF CORRECTION. Patent ,No. 2,562 ,L 55. November], 19th.

LOUIS c. HILKEIIE-iER;

It is hereby certified thaterror appears in the printed specification of the above numbered. patent requiring correction as follows: Page 5, sec- 0nd column, line 56-, claim 2; after the word bracket strike out "an and that the said Letters Patent shouldbe readwith this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 15th day of February, A. 1). 19t5.

Leslie Frazer (Seal) Acting Commissioner of Patents.

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