US2308901A - Concrete mixer - Google Patents

Description

Jan. 19, 1943. HAL 2,308,901

CONCRETE MIXER Filed June 5, 1941 3,Sheets-Sheet 1- I .32 gmmiww/ GeorgeKVz'all Louis amzke ier,

Jan. 19, 1943. G ALL ET AL 2,308,901

CONCRETE MIXER Filed June 5, 1941' 3 Sheets-Sheet 2 and i Louis 6'. llillcemeier,

Jan. 19, 1943.

G. K. VIALL ET AL CONCRETE MIXER I Filed June 5, 1941 3 Sheets-Sheet 3 jam/Mom I aeorgeffin all, and

- L0 uia G'Hillremeier;

Patented Jan. 19, 1943 CONCRETE MIXER George K. Viall and Louis G. Hilkemeier, Milwaukee, Wis., assignors to Chain Belt Company, Milwaukee, Wis., a corporation of Wisconsin Application June 5, 1941, Serial No. 396,768

9 Claims.

The invention relates to concrete mixers or agitators, more especially those of the rotary drum type having a charging opening in the drum through which at least the cement and aggregates are introduced for mixing, and a duct or hopper associated with such opening for primarily receiving such materials, as from the chutes of storage bins at a batching plant, and conducting or feeding them to and through the opening. A typical example of such apparatus is to be found in the prior application of our co-worker, Charles F. Ball, filed December 6, 1939, Serial No. 307,784, now Patent No. 2,265,- 751, granted December 9, 1941, and for purposes of the present disclosure the invention has been illustrated and will be described in connection with such a mixer, although, as will be readily appreciated by those skilled in the art, it is not necessarily limited to such a construction.

The mixer or agitator f the said Ball application is of the truck-mounted type, with the mixing drum mounted upon the truck chassis for rotation about a longitudinal axis which is inclined to the horizontal. The lower end of the drum is closed, except that in most instances a water supply pipe passes axially through the lower head, while the higher end, which is or may be frusto-conical in form, is open to provide an ingress and egress passage for the raw materials and the mixed concrete respectively. A shaft. is secured to the drum adjacent such opening and extends axially outward therefrom, and a charging duct or hopper structure is slidably but non-rotatably mounted on said shaft for reciprocating movements toward and from the opening. The interior of the drum is provided with helical mixing blades of appropriate design to worm the material upwardly to and through the drum opening, or downwardly away therefrom, dependent upon the direction in which the drum is rotated, which direction may be controlled at will by the operator. The normal position of the hopper structure is inward on the shaft with its lower end in co-operative relation to the drum opening to feed the cement and/or aggregates to and through the opening. It also occupies this position while the materials are being mixed within the drum,-during which time it serves to prevent discharge of such portions of the partially or completely mixed materials as may rise or be worked up by the mixing blades to above the lowest point of the drum opening, since such portions merely enter into and circulate in the hopper structure, and return to the drum by gravity action. When it is desired to discharge the completed mixture the hopper structure is moved outwardly on the shaft to space its lower end from the drum opening, whereupon as the mixture is wormed up to the opening by the helical blades it Will fall between the drum end and hopper structure into a discharge chute or receptacle positioned below the opening and hopper structure.

' The hopper structure is open at its top so that upon arrival at the batching plant it is only necessary to spot the machine with the hopper in position beneath the discharge chutes of the supply bins, whereupon the desired measured quantities of cement and aggregates may be quickly transferred to the drum. The open top of the hopper however, will also permit the entrance into the drum of undesired materials or substances either before the truck reaches or after it leaves the supply bins. For example, the mixer may be caught in a sudden shower in transit or on the job, during which rain water may enter the drum through the hopper in sufficient quantities to materially change the watercement ratio in the mix, with consequent ill effects upon the concrete.

It is the principal object of the present inven tion to provide relatively simple but effective mechanism for protecting the drums and hoppers against the entry of any such undesired substances or materials.

It is a further object of the invention to provide mechanism of that character which will in no way interfere with the normal functioning of the charging device.

It is a still further object of the invention to provide mechanism of the kind described which may be simply and quickly manipulated to permit the introduction of the cement and aggregates into the hopper and drum, and will not interfere with the discharge of the mixture from the drum. It is a still further object of the invention to provide mechanism of the class described which will automatically accommodate itself, while in its protective position, to the movements of the hopper structure to and from the position in which the mixture may be discharged from the drum.

It is a still further object of the invention to provide protective or shielding mechanism for the charging hopper structures of concrete mixers which may be remotely controlled; as for example, in the case of a truck-mounted mixer having a charging hopper at its rear end, the

protective mechanism therefor may be manipulated from the truck cab or adjacent thereto.

It is a still further object of the invention to provide mechanism of th class described which, while effectively accomplishing its intended purpose of excluding undesired materials or substances from the mixing drum, will at the same time preserve free communication between the interior of the drum and the outside atmosphere, whereby dangerous building up of gaseous pressures resulting from the chemical reactions between the cement and water of the mixture will be avoided.

With the above and other objects in view, which will appear as the description proceeds, the invention resides in the novel details of construction, and in the novel combinations and arrangements of parts, more fully hereinafter described, and pointed out in the appended claims.

Referring to the accompanying drawings forming a part of this specification, in which like reference characters designate like parts in all the views:

Figure 1 is a side elevational View of the essential elements of a truck-mounted concrete mixer of the type set forth above, showing one form of protective mechanism for the hopper, constructed and arranged in accordance with the present invention, applied thereto;

Fig. 2 is an enlarged fragmentary plan view of theparts shown in Fig. 1;

Fig. 3 is a still further enlarged fragmentary elevational side elevational view, partly broken away and in section, of the shield and its actuating mechanism;

Fig. 4 is an end elevational view, also partly broken away and in section, as seen from the right of Fig, 3;

Fig. 5 is a fragmentary side elevational View, partly in section, of the control lever and linkage for the shield;

Fig. 6 is an end elevational view of the same, as seen from the left of Fig. 5;

Fig. '7 is a detail sectional elevational view of one form of means for accommodating the shield to the movements of the hopper to and from discharge position, taken approximately on the plane indicated by the line of Fig. 4, looking in the direction of the arrows;

Fig. 8 is a fragmentary side elevational view of a somewhat modified form of the invention;

Fig. 9 is an end elevational view of the parts illustrated in Fig. 8, as seen from the right of the latter Figure;

Fig. 10 is an enlarged horizontal sectional plan view, taken approximately on the plane indicated by the line Ill-40 of Fig. 8, looking down; and

Fig. 11 is a sectional elevational view, taken approximately on the plane indicated by the line Il-ll of Fig. 8, looking in the direction of the arrows.

Referring more particularly to Figs. 1 to '7 inclu'sive of the said drawings, the concrete mixer or agitator here shown comprises the mixing or agitating drum or receptacle l5 mounted upon the chassis E6 of a motor vehicle for rotation about a longitudinal axis I! which is inclined to the horizontal as in the said prior Ball application. The drum 15 may be rotated in either direction at the volition of the operator through a suitable power transmission l8 deriving power either from the truck motor or from an independent motor in accordance with well known practice. At the rear upward end of the drum, which as above indicated is open to provide a asoaeoi charging and discharging opening, the apparatus is provided with a hopper device slidably but non-rotatably mounted upon a shaft, not shown, but carried by the drum and extending axially outwardly from the rear end of the drum. The said hopper device is reciprocated upon the said shaft along the axis I? by suitable connections including hand operated gearing 2|, being movable from a normal position in which its lower or discharge end is in proximity to the drum opening whereby to transfer the concrete materials through the latter, to a discharge position in which the said lower end is spaced from the drum end so that the mixture, as it is moved upwardly in the drum by the mixing blades, will be discharged from the opening, dropping between the drum end and the hopper device into the discharge chute 22. The said hopper 20 is perimetrally closed but is open at the top, and as above indicated not only the desired concretemaking materials may enter through this open top but also undesired substances such as the rain water above mentioned.

The mechanism for preventing the entry of such undesired materials comprises a plate of suitable shape and dimensions to overlie and protect or shield the open top of the hopper, which plate has a resilient connection 2'6 with one end of a curved arm 21. As best shown in Figs. 4 and 7, the other end of said arm is journalled in a sleeve 28 which is rigidly carried by a link 29 pivotally mounted as at 30 in ears 3! carried by an upright hollow shaft or tube 32. This tube 32 is journalled in bearings 33 and 34 carried by members 35 of the mixer framework and adjacent the lower bearing 34 it rigidly carries the bracket arms 35 by means of which it may be oscillated in the said bearings as will appear more fully below.

The link 29 extends through slots 31 provided in the upper end of the tube 32 and has pivotally connected to it as at 38 an elevating shaft 39 which extends downwardly within the tube 32. This shaft has pivotally connected to its lower end as at 46 an arm 4| which is rigidly carried by the stub shaft 42 journalled in the free ends of the bracket arms 36, as will be clear from Figs. 3 and 4. The said stub shaft is connected by a universal joint 43 to an operating rod 44 which extends forwardly to a point preferably adjacent the cab of the vehicle, as indicated in Fig. 1. Here the said rod is pivotally connected as at 54 to the operating lever 45 mounted in a slot 46 of a plate or bracket 41, which slot has an offset 48 at its forward end into which the said lever may be laterally moved to normally look the parts in the positions shown in Figs. 1 and 2.

The rod or shaft 44 is slidably and rotatably mounted in a bearing bracket 49 carried by the plate or bracket 41 and the lateral movements of the operatinglever 45 to and from the offset 48 of the slot 46 will impart oscillatory movements to the shaft 44 as indicated in Fig. 6. The lower end of the lever 45 is pivotally connected asat iii] to a pair of links 51 which in turn are pivotally connected as at 52 to the downward extension 53 of the bearing 49, the pivotal connections 59 and 52 being sufficiently loose to permit of the lateral displacement of the lower end of the said lever 45, as indicated in said Fig. 6. In addition to the oscillatory movements thus imparted to the shaft 44, swinging movements of the lever 45 in the slot 45 about the pivot will impart longitudinal movement to the said shaft and inturn to the arms 35 carried by the tube 32.

It results from the construction so far described that with the parts in the positions illustrated in full lines in Figs. 1 to 4 inclusive, if the operating lever 45 be moved laterally to disengage it from the oifset 48, such lateral movement will impart arcuate movement to the shaft 44 which will be transmitted through the universal joint 33 to the stub shaft 42 and by the arm 4| carried thereby to the elevating shaft 39, the upward movement of which will raise the link 29, sleeve 28, arm 21 and the shield plate 25 about the pivot 38 to the broken line position illustrated in Fig. 4. Longitudinal movement of the operating lever 45 in the slot 46 will then transmit longitudinal movement to the said shaft 44, which in turn will be transmitted through the universal joint 43 to the arms which will cause arcuate movement of the tube 32 in its bearings 33 and 3d, thereby swinging the arm 2'! and plate 25 about the vertical axis of the tube 32 to move the parts from the full line position shown in Fig. 2 to the broken line position indicated therein, thereby moving the shield plate 25 to an ineifective position so far as the hopper 2G is concerned to permit the introduction into the hopper and from it to the mixing drum of the cement and aggregates from the supply bins or other source of supply. After the materials have been charged into the hopper and drum the lever 55 is returned to its initial position during which movements the shield and its actuating members will be returned to their respective initial positions by movements in the reverse order from that above described.

As above indicated the hopper 29 is movable by the mechanism 2| axially away from the charging opening for discharge purposes. Since such movements are rearwardly and upwardly due to the inclination of the drum axis and the rum-carried shaft upon which the hopper is mounted, it is preferred to provide resilient or other yielding means in the shield mounting whereby to accommodate the shield to such hopper movements. The mean-s here shown for this purpose are incorporated into the sleeve connec tion 28 for the curved arm 2! and comprise the pin 55 carried by and extending through the arm 2'5 and Working in slots 56 provided in the wall of the sleeve 28, see Figs. 4 and 7. One end of a coil spring 59 is secured to the said pin 55 While the other end of the said spring is secured to a pin or stud 50 which is rigidly carried by the sleeve 28. It thus results that as the hopper 20 moves upwardly and rearwardly the upward component of such motion will elevate the plate 25, the arm 21. journalling in the sleeve 28 and through the pin 55 tensioning the spring 59, which latter will of course retain the plate in engagement with the hopper and cause it to maintain such engagement as .the hopper is again lowered. During the outward and upward hopper movement the outward component will be taken care of by the hopper merely sliding somewhat from beneath the shield as indicated in broken lines in Fig. 3.

As was above mentioned, it is desirable to have the shield maintain open communication between th interior of the drum and hopper and the outer atmosphere in order to prevent the building up of dangerous pressures within the drum due to gases generated as a result of the chemical reactions between the water and the cement.

To this end the hopper is preferably provided with a plurality of spacing members 62 extending a slight distance above the upper edge of the hopper and which are contacted by the plate 25 in its normal position, as clearly shown in Figs. 1, 3 and 4. These members 62 of course keep the plate 25 spaced sulficiently from the hopper to permit of the escape of any gases which may be generated within the drum, and also to promote the free circulation of air within the drum from the outer atmosphere, but the spacing is not great enough to allow undesired substances in appreciable quantities to enter into the hopper.

In the somewhat modified form of the invention illustrated in Figs. 8, 9, 10 and 11, the arm 21 which carries the shield 25 is journalled in the upper curved end of the tubular shaft 65, there being a resilient connection, such as that shown in Fig. 7 and above described, provided between the arm and tube as shown in Fig. 9. The tubular shaft 65 is vertically mounted in bearings 66 and 57 carried by the frame members of the mixer unit for both oscillatory and axial movements which are sequentially imparted thereto by the elements shown at the lower por tions of Figs. 8 and 9 and somewhat more in detail in Figs. 10 and 11.

These elements comprise an arm ill journalled on the lower end of the vertical shaft 55 but held against longitudinal movement thereon. The arm is provided with a downwardly extending lug or projection H which engages the upper surface of the bearing bracket El. This bracket is provided with an inclined camming portion 12 over which the said projection may travel, as best shown in Fig. 11, as the arm it is oscillated by means of the reciprocating rod or shaft 13 which extends forwardly in the same manner as the rod 44 above described, and is operable by a hand lever 14 moving in a slot 15 formed in the plate or bracket 16 mounted adjacent the forward end of the mixer unit. This lever 1'4 is also laterally movable in much the same manner as the lever 45 above described into and out of an offset 1'! with which the slot 75 is provided. However in this instance the lateral movements of the said lever are utilized solely for locking purposes and are not translated into oscillatory movements of the connecting rod 73, since the elevation of the shield 25 preparatory to its being swung from over the hopper is accomplished through the camming action of the lug or projection H riding up the camming surface E2 of the bracket 51. This camming action of course raises the arm 70 which, being held against axial movement on the vertically extending shaft 65, elevates the latter bodily and with it the arm 21 and plate 25.

The shaft 65 is provided with a rigid arm 85) mounted just above the arm H1 and having an adjustable stop screw 8! which is engageable with a lug or projection 82 rigidly carried by the upper surface of the arm It. The parts are so constructed and arranged that the lug 82 will not engage with the stop screw 81 until the elevating lug H has moved to the broken line position indicated in Fig. 10 and substantially completed its elevating function due to its movement over the inclined camming surface 12; but when this action has been completed engagement of the lug 82 with the stop screw 8! will then transmit any further arcuate movement of the arm 10 to the arm and through it to the shaft 65, thereby swinging th arm 21 and shield 25 to the inoperative position similar to that indicated in broken lines in Fig. 2, and uncovering the hopper for the admission of concrete constituents. A spring 85 may be attached to the arm 80 and to some fixed element, as for example one of the frame members, to return the shield 25, arm 21 and vertical shaft 65 to the normal or operative position of the parts, as will be readily understood from Figs. 8, l0 and 11. A cushioning spring 8'! may be interposed between the bearing bracket 66 and a collar 88 carried by the tubular shaft 65, to reduce noise in transit.

The shield illustrated in Figs. 8 and 9 is shown as slightly dished to assist it in shedding rain water, and the said shield is preferably spaced from the upper edge of the hopper by spacing members 62 as in the preceding form.

While two forms of the invention have been illustrated and described it is obvious that those skilled in the art may vary the details of construction as well as the precise arrangement of parts without departing from the spirit of the invention and therefore 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 or agitator having an agitation receptacle provided with an opening for the charging of the concrete materials thereto and the discharge of the mixture therefrom, and an open hopper device for receiving and transferring the materials to and through said opening, said hopper device being movable away from the opening for the discharge of the mixture, a shield for said hopper device, normally positioned to exclude materials from the hopper opening; means mounting said shield separately from the hopper while accommodating the movements of the hopper to and from discharge position; and means for moving the shield to an ineffective position relative to the hopper opening when it is desired to admit materials .to the hopper.

2. In a concrete mixer or agitator having an agitation receptacle provided with an opening for the charging of the concrete materials thereto and the discharge of the mixture therefrom, and an open hopper device for receiving and transferring the materials to and through said opening, said hopper device being movable away from the opening for the discharge of the mixture, a shield for said hopper device, normally positioned to prevent entry of materials into the hopper; means mounting said shield separately from the hopper said means being yieldable to accommodate the movements of the latter to and from discharge position; and means for moving the shield to an ineffective position relative to the hopper when it is desired to admit materials to the latter.

3. In a concrete mixer or agitator having an agitation receptacle provided with an opening for the charging of the concrete materials thereto and the discharge of the mixture therefrom, and an open hopper device for receiving and charging the materials to and through said opening, said hopper device being upwardly movable away from the opening for the discharge of the mixture, a shield for said hopper device, normally positioned to prevent entry of materials into the hopper; a mounting for said shield, supporting it independently of the hopper and including means resiliently urging it into engagement with the hopper to accommodate the upward movements of the latter to its discharge position; and means for moving the shield to an ineffective position relative to the hopper when it is desired to admit materials to the latter.

4. In a concrete mixer or agitator unit having an agitation receptacle provided with an opening for the charging of the concrete materials thereto and the discharge of the mixture therefrom, and an open hopper device for receiving and charging the materials to and through said opening, said hopper device being movable outwardly and upwardly away from the opening for the discharge of the mixture, a shield for said hopper device, normally positioned to prevent admission of materials into the hopper; means mounting said shield eparately from the hopper while normally maintaining it in engagement with the hopper, said mounting means being yieldable to accommodate the upward component of the hopper movement, and the hopper sliding beneath the shield to accommodate the outward component of said movement; and means for moving the shield to an inefiective position relative to the hopper when it is desired to admit materials thereto.

5. In a concrete mixer or agitator unit having an agitation receptacle provided with an opening for the charging of the concrete materials thereto and the discharge of the mixture therefrom, and an open hopper device for receiving and charging the materials to and through said opening, said hopper device being rectilinearly movable away from the opening on an axis inclined to the horizontal for the discharge of the mixture, a shield for the hopper opening; a resilient mounting for said shield supporting it independently of the hopper and normally maintaining it in engagement with the hopper to prevent entry of materials thereto while yieldably accommodating the upward component of said hopper movement, the outward component of which is accommodated by sliding of the hopper relative to the shield; and means for moving the shield to an ineffective position relative to the hopper when it is desired to admit materials thereto.

6. In a concrete mixer or agitator unit having a frame, an agitation receptacle provided with a material transfer opening mounted in said frame, and an open hopper device for receiving and charging at least the solid constituents for the mixture into the receptacle through said opening, said hopper device being upwardly movable away from the opening for discharge of the mixture; means for excluding undesired mate rials from said hopper and receptacle, comprising a shaft journaled on the frame adjacent the hopper for movements about a vertical axis; an arm extending substantially horizontally from said shaft toward the hopper and journaled for movements about an approximately horizontal axis; a shield carried by said arm for controlling the entry of materials through the open top of said hopper; means yieldably biasing said arm about said horizontal axis to maintain said shield in operative position relative to the hopper while accommodating said upward movement of the latter for discharge; and means for sequentially bodily elevating said arm and shield from the hopper, and then swinging said shaft, arm and shield about said vertical axis, to remove the shield from the hopper for charging.

'7. In a concrete mixer or agitator unit having an agitation receptacle provided with a charging opening, and a charging hopper for receiving and transferring concrete materials to said opening, means for excluding undesired materials from said hopper comprising a vertical shaft mounted adjacent and separately from the hopper; a shield for the hopper carried by said shaft for vertical and horizontal movements to and from a position in which it may prevent entry of materials to the hopper; means other than the shaft for imparting said vertical movements to the shield; an operating lever; and connections between the lever, shaft and vertical moving means whereby actuation of the lever will cause said means to elevate and lower the shield and said shaft to impart horizontal movements thereto.

8. In a concrete mixer or agitator unit having an agitation receptacle provided with a charging opening, and a' charging hopper disposed in cooperative relation to said opening for receiving and conducting concrete materials thereto, means for excluding undesired materials from said hopper comprising a vertical shaft mounted adjacent and independently of the hopper for rotative and axial movements; a shield carried by said shaft for vertical and horizontal movements to and from a position relative to the hopper in which it may prevent entry of materials to the hopper; an operating lever; and connections between said lever and shaft including cam means for imparting initial axial moveinents to the latter, whereby the shield may be moved from its eflective position.

9. In a truck-mounted concrete mixer or agitator of the type wherein a mixing or agitating unit is mounted adjacent the truck cab and comprises a frame, an agitation receptacle provided with a charging opening at a distance from the cab, and an open charging hopper disposed in co-operative relation to said opening for receiving and transferring concrete materials thereto, means for excluding undesired materials from said hopper, comprising a shield mounted on said frame for movements to and from a position over the hopper in which it may prevent the admission of materials thereto; an operating lever mounted adjacent the truck cab; and connections between said lever and shield for moving the latter to and from its said position.

GEORGE K. VIALL. LOUIS G. HILKEMEIER.

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