US2544085A - Apparatus for charging and discharging concrete materials - Google Patents

Description

March 6, 1951 G. HILKEMEIER 2,544,085

APPARATUS FOR CHARGING AND DISCHARGING CONCRETE MATERIALS Filed Jan. 29, 1948 2 Sheets-Sheet 1 LOUIS G. HILKEMEIER INVENTOR AT TORNE Y March 6, 1951 2 Sheets-Sheet 2 Am HU V /3.9 I l uh. L.G.H|LKEME|ER v x I I lllll INVENTOR /Z3 l MIHIII ATTORNEY Patented Mar. 6, 1951 UNITED STATES PATENT OFFICE 5. C aim i This invention relates to. concrete. mixers; and: in particular to the. mounting. for the. charging. hoppers usedtherewith and has matterdescribed. herein which isdisclosed and claimed in the.co.-..

pending-.- application of Roy M. Hawkins, entitled Apparatus for- Charging and Discharging Con-=.

crete Mixers, filed December 2'1 1947, Serial. No. 794150, and the application of Louis G. Hilkemeierand Roy M, Hawkins, entitled Apparatus for Charging and Discharging Concrete Mixers, filed January 12, 1948, SerialNo. 1,743.

In truck mounted concrete mixers it is now widespreadpractice tomount the mixing drum on an axis which is inclined as regardsto the horizontal. Associated with such mounted mixers is a charging hopper, an example of such a hopper is shown in the Letters Patent issued to R. J. Barnes on May 1, 1945-, 2,374,912. The use of such apparatus has a great; advantage in that it enables thechar-g-ing and-discharging of the mixing drum contents through a single opening. However, since; the mass-of concrete. is an abrasive substance any apparatus used therewith must necessarilybe subject to abrasive wear. Inthe aforesaid Letters Patent to R. J. Barnes a charging hopper mounting for truck type concrete mixers is disclosed which'has-some advantages over the prior art. Nevertheless suchstructure has been found to have inherent failings which necessitated costly repair and replacement after comparatively short periods of use. This is by reason of thefact that a rotatable closure ring is journalled on a; nonrotatable hopper; a seal is provided and also thrust accommodating means. The structure of-the said thrust accommodating means when viewedwiththe mounting apparatus as a whole was such as to wear very rapidly especially when abrasive substances beoamelodged therewith. For; all of the forcenecessary to bring the rotatable closure ring into sealing engagement with the drumis exerted through the. thrust assembly, hence the thrust accommodating means-quickly wore out. Such a condition usually requires expensive. repair or replacementof thehopper apparatus and results in much lost-time.

Accordingly, it is an object of: this invention to.

provide pivotally mounted charging; hoppersfor concrete mixers with. means necessary. to seal the.

mouth of thedrum opening,- which exert the necessary force through the rotatable closure ring instead of through-the-entire hopper assembly.

The foregoing is necessarily the broad object of this invention, however other objectswil'lappear to those skilled inthe. art inthereading of the following description and claims.

In the figures, Fig. 1 represents a front elevation'- partlybroken away, of a: charging hopper mounted on an inclined axistruckmixerl Fig. 2-isa sideelevationpartly broken away; of theihopper-mounting.

Fig. 3 is an enlarged view, partly in section, of the: apparatus shown in Fig. 2.

Referring to, the figures, Fig. 1 shows a mixing drum H2 of the inclined axistype mounted to the frame H! of theconventional type, truck mixer. Pivotally mounted to said frame is the hopper I H] which directs materials into the drum during the charging operation. i-he hopper and closure ring function accordingly, when the hopper is pivoted about the shaft 12'! the rotatable closure ring I23 is free of the mouth H3 of the mixing drum and thecontents can be discharged therefrom, when the hopper is again brought into engagement with the mouth of the mixing drum the. rotatable closure ring I23 seats itself on the mouth of the mixing drum, sealing the same. The hopper is in this position during most of the time that the truck mixer is in operation, as charging and discharging operations are relatively infrequent during normal operations.

The hopper is supported by, means of the arms I253 which are pivotally connected to the rock shaft I21. These arms are not keyed to said shaft but are free to rock thereabout. They are flex ibly mounted to the nonrotatable hopper by means of deformable or rubber-like bushings Hi5 which engage a bushing I46, said bushing registering with the pin H8 which is attached to the hopper llll. Although not shown in the drawings, it will be appreciated that the aforesaid arm and bushing structure is duplicated on the opposite side of the hopper, a pin similar to pin H8 being in alignment with pin H8 with their axes approximately intersecting an extension of the drum axes. A resilient connection 528 is provided between the hopper Hi3 and the arm lift and is so arranged so that the hopper will not tip when it is in a raised position. In this manner a resilient support for the hopper mechanism is afforded which may accommodate the erratic movements of the drum openingas respects to the frame of the mixer when the truck mixer travels over rough terrain, such travel occasioning weaving and twistingof the frame.

The hopper is moved from a dischargeposition to a charging position by pivoting the same about the shaft I21. This'is accomplished by having arms I M keyed to said shaft: a lever 526 is likewise keyed to said shaft and a rodmember 125 is attached to said lever; the rod I25 may be moved by means of any conventional bell and crank mechanism by the manipulation of an operator. The levers I have a lost motion connection I50 which cooperates with an enlarged portion of the pin I I8, this arrangement moves the hopper toward and away from the mouth. of the drum opening when theshaft l2l'is rocked in the corresponding direction.

Fig. 3 shows the rotatable closure ring I23, the hopper ID. and the. connecting means between themwhich includesa sea-l Miand' athrust plate I42 which is an annular member integral with the closure member and is set in the groove I4I of the hopper III]. In the prior art all of the force required to bring the rotatable closure ring I23 into sealing engagement with the mouth of the mixing drum H3 was exerted through and upon the thrust ring I42 as shown in the aforesaid Barne patent. This force is necessarily great and brought about the condition in a short time wherein the thrust ring was so badly worn that it had to be replaced. Also the rotatable closure member I23 was displaced axially toward the mouth of the mixing drum so that the seal I44 had no effectiveness, consequently great expense was entailed to repair this deficiency. Fig. 3 shows a track member I22 integral with the rotatable closure ring I23. A rolling member I39 rides on the track member I22, this rolling member is integral with the lever H4 and is so arranged to exert all the force necessary to bring the rotatable closure ring I23 into sealing engagement with the mouth of the mixing drum I I3 through or directly upon the rotatable closure ring itself. This obviates any excessive thrust on the thrust ring I42 as only the weight of the hopper is absorbed by said ring and it is free to .float in the hopper groove MI.

As the hopper H9 is brought adjacent the :mouth of the mixing drum H3 it mates with the Lfiared opening divided at said mouth and before the rotatable closure ring effectively seals the .mouth of the drum there must be some adjust-' ment of the rotatable closure ring to the axis of rotation of said month. In the past this sometimes accounted for eccentric movement of the rotatable closure ring as respects to the mouth of the drum because the adjustment was not possible, with consequent strain upon the hopper mounting apparatus. In this embodiment of the invention clearance exists between the lost motion aperture I50 and the pin H8 as shown in Figs. 1 and 2. It will also be noted that there is lateral clearance between the head of said pin and the lever arm H i, also on the opposite side L there is clearance between the lateral faces of levers H4 and I29. This enables the rotatable closure ring and the entire hopper assembly to float before finding its conoentricity with the mouth of the mixing drum. The roller I39 is shown as the chosen embodiment to urge the closure ring forward, however it can be appreciated that sliding contact means might otherwise be used. Also, equivalents other than those of the chosen embodiment are not shown but may be selected byone skilled in the art. Hence, the invention is to be limited only by the clear import of the following claims.

I claim:

1. In a transit concrete mixer, a drum rotatably mounted on an inclined axis and having its rear elevated end open; a charging hopper; a stationary frame pivotally mounting the charging hopper to swing toward and from the elevated open end of the drum; a sealing member carried by the charging hopper and engageable in sealing relationship with the mouth of said drum when the charging hopper is in its lowered position; means for winging the charging hopper upwardly away from the open end of the drum to enable discharge of the drum'contents, said means further comprising actuatable lost motion linkage connected to the hopper; means for urging said sealing member into sealing relationship with the mouth of said drum, said means being attached 4 to said swinging means and arranged to exert the force necessary to seal the drum through the sealing member.

2. In a concrete mixer, a rotatable mixing drum having an open end through which the drum is charged and discharged; a charging hopper; a pivotal support for said hopper, a rotatable closure member on said hopper arranged to seal said open end of the drum when the former is brought into engagement therewith, means for urging said rotatable closure member into engagement with the mouth of said drum, said means including movable arms on each side of said drum having lost motion connections with said hopper and engaging said rotatable closure member, whereby said means perform the dual function of opening and closing the mouth of said drum while exerting the force necessary to seal said drum when the hopper is in a closed position through the rotatable closure member.

3. Hopper mounting apparatus for transit concrete mixers wherein the hopper has a rotatable closure ring journaled thereon, comprising freely pivoted arms for supporting said hopper assembly for movement about a pivot point, lost motion linkage means for moving said hopper assembly about its pivot point, said lost motion linkage further comprising movable means abutting a trackwa on the rotatable closure ring for urging the same into sealing engagement with the mouth of an associated mixing drum, and means for actuating said lost motion linkage to move the hopper from a discharge position to a charging position and vice versa.

4. In a concrete mixer, a rotatable mixing drum having an open end through which the drum is charged and discharged; a charging hopper; a pivotal support for said hopper, a rotatable closure member on said hopper arranged to seal said open end of the drum when the former is brought into engagement therewith, a trackway on said rotatable closure member, means for urging said rotatable closure member into engagement with the mouth of said drum, said means comprising movable arms on each side of said drum having lost motion connections to said hopper whereby said means perform the dual function of opening and closing the mouth of said drum while exerting the force necessary to seal said drum when the hopper is in closed position through the rotatable closure member, said movable arms having moving contact members for engagement with said trackway on the rotatable closure member during the sealing step.

5. Apparatus according to claim 4 in which the lost motion connection to said hopper engages pin-like members disposed substantially on the diameter of said hopper, said lost motion connection to the pin-like member having lateral and transverse clearance with said pin-like members whereby the hopper assembly may float while searching for its concentricity with the axis of the mouth of said mixing drum.

LOUIS G. HILKEMEIER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 773,375 Cooper Oct. 25, 1904 999,525 Shero Oct. 1, 1911 1,848,223 Reed Mar. 8, 1932 2,374,912 Barnes May 1, 1945

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