US1298743A - Rotary concrete-mixer. - Google Patents

Description

E. H. LICHTENBERG.

ROTARY CONCRETE MIXER.

APPLICATION FILED NOV 28. IQIE.

Patented Apr. 1, 1919.

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Yt AiFEFi i W @h h ltlfil ERICK H. LICHTENBERG, OF IVHLVI'AUKEE, WISCONSIN, ASSIGNOB T0 KOEHRING MASI-HNE COMPANY, OF MILWAUKEE, 'WISCQ'NSEN, A CUBEORATION.

scream CONCRETE-MIXER.

isconsin, have invented oerlinprovcments in lice tary Concrete-liiixers of which thefollowint: a specification. i,

There is at the present time. a commonly used type of concrete mixer known as the rotary type, in wl'iich the construction involv the provision of a rotary drum prod o upon its interior with suitable mixing devices, supported upon rollersengaging a portion or portions of the exterior ol the drum, and operated so as to revolve loy means of suitable driving mechanism.

in this type of mixer it is customary utilize a drum structure which involves the formation exteriorly of the drum and on its 'phery, of one or more runways or races which runways engage a supporting or rollers carrying the weight of the roiler drum and its contents and forming practically anti-friction bearings for the drum.

in the practical use of mixing drums such. as referred to the mixing means within the drum com rises devices adapted to out through the aggr atcs or materials being mixed. to elevate said. materials and pitch them laterally toward an end of the drum, and other similarly acting instruinentalities to reverse the movement of the materials in the drum, all with a view to thorough admixture. of said materials.

it is necessarily incident. to the above operation of the mixing means of the drum that, various increasing and decreasing thrusts are caused as regards the tendency of the drum 'to move endwise in acting on the load operated upon in the manner set, forth and all endwise thrusts are ordinarily received upon the hearing portions between the sup iorting rollers of the drum and the runways on the periphery of the drum.

A large amount of end thrust during the rotation of the drum is frequently caused as an incident to the use of the mixer when located upon e'rades not truly horizontal, and on account of which one end of the mix-- lug drum is often lower than the other end or in other words the positioning); of the drum attended by a'ilisposition of the same at an inclination to the horizontal resulting in uneven stresses upon the roller or Specificatiofi of Letters Patent.

111 the county of Milwaukee a.

to v

Patented Apr. 11 1919.

Application filed November as, 191$. Serial No. 133,896.

rollers and runways engaged thereby and consequent end thrust tendencies of the drum during rotation. v Heretofore it has been common to con struct one or and runways above referred to as used in mixer construction utilizing endwise pitching' mixing devices, with straight hearing surfaces practically interlocking the inixerwith the rollers to prevent endwise or side play 55 of the drum during rotation, and as a result, on account of the exceptional end thrust tendencies of the drum in mixing and when supported at an inclination to the horizontal, the contacting uortions of the runways and rollers have had a shearing engagement to such an extent that a shearing action between these parts has been produced tending to cut into the runways suiiiciei'itly to seriously damage the same, create unusual looseness or play between the supporting rollers and the drum and obvious resulting disadvantages. Indeed in some instances the wear or cutting away of the runways has been such as to require entire replacement of the heads of the drain which are equipped with said runways by reason of integral formation therewith and the expense and loss aside from the disadvantageous incapacitating of the mixer from the foregoing, noel-zesthe provision of preventing means a serious desioeratum in the art.

The object of the present invention has been to so design the runways and supporting rollers of mixing machines of the type set forth as to obviate the difficulties to sultingviu the constructions heretofore employed and which have been fully presented herein. above endis clearly set forth in the following detailed description and illustrated in the accompanying drawings, in whioh Figure 1 is a. sectional View showing the general construction of the mixing drum, L00 supporting rollers, and driving gears of f what is known as the Koehring mixer, with the invention adapted thereto,

191g, 2 is a fragmentary side View bringinn; out more fully the manner in which the supporting rollers of thedrum engage the side bearing wheels of the runways to accommodate for resistance of 'lateral thrust tendencies of the drum in action.

Fig. 3 is an enlarged sectional View of both of the supporting rollers 60 itself resulting 85 The construction employed to the' 95 .one of the supporting rollers constructed in accordance with the invention;

Fig. 4 is a fragmentary section bringing out more fully the engaging relation between a supporting roller and the drum in the embodiment of the invention; and

Fig. 5 is a fragmentary sectional view showing a modified embodiment of the invention.

In the drawings, A denotes a mixing drum of the rotary type having the diagonally disposed blades 1 therein and associated with the elevating buckets 2 andthe reversible mixing and discharge chute 3. The manner in which the materials in the drum are operated upon by the parts 1, 2 and 3 is roughly illustrated in Fig. 1 and discloses how theend thrust tendencies of the drum as an incident to the mixing action are incurred.

The drum A is supported by one or more rollers 4 operating in contact with the runways 5 on the drum- A, said rollers taking, oi? course, the down thrust of the drum and its contents during the revolution of the drum. The rollers 4 are chilled on their peripheries and the runways 5 are formed integral with the drum and are comprised of a base or race portion with which the peripheries of the rollers 4 contact, and a side wall 5 really consisting of the end wall of a flange 6 likewise formed integral with the drum structure. Each flange 6, of which two are preferably provided, formed. integral with the opposite heads of the drum A, isreally a gear formed with teeth 7 engaged by the driving pinions 0r gears '8. The gears 8 are driven by the motor used for operating the'mixing machine including the drum A, the latter. being driven directly by the gears 8 meshed with the teeth of the flanges 6. It will be observed that the side wall 5 of the runway 5 is formed on a bevel or inclination which may be described as leading diagonally inward or toward the middle of the drum from the point of 'Iherging with the base of the runway. Likewise it will be observed from Fig. at that the portion of the rim of each roller 4 engaging with the portion 5' of the runway 5 is pivoted or formed on an inclination corresponding with the bevel of the wall 5. In this man-- ner an effective end thrust bearingis provided between the parts 4 and 5 and it becomes impossible for the inner edge of the roller 4 at its periphery or rim to engage with the outer edge periphery of the flange .6 and cause a resulting shearing oflor cutting action between these parts which has been incident to previous constructions wherein the contacting portions of the rollers 4 and flanges 6 have been disposed in a flange in that it is drum and each having a beve spective runways the. said plane substantially at right angles to the axis of the drum and the rollers 4.

As a further detail feature of construction, it may be noted also that the teeth 7 formed in the flange 6 for meshing relation with respect to the gears or pinions 8, terminate short of the end of the flange 6 forming the side wall 5 of the runway 5, avoiding any liability therefore of engagement between the rollers 4 and. said teeth. Whether the drum A be positioned with its axis at the-outer horizontal or at an inclination to the horizontal, it will be evident that liability of shearing off of the runway 5 at its end thrust portion or wall 5 is wholly avoided and the same is true in respect to the end thrust tendencies of the mixer drum itself when acting upon its contents in pitching the latter back and forth with respect to the ends of the drum and interiorly of the latter.

7 It will be observed on reference to Fig. 5 that a slightly different arrangement of the runway 5 roller 4 and gear teeth 7 is provided. In this modifiiiation the construction of the roller 4 is substantially the same as heretofore presented in respect to the ,roller 4. The runway 5 however, is spaced from the ring of gear teeth 7 to the extent particularly that the end wall 5 of the runway is formed in the head of the drum at a point a short distance from the adjacent terminals of the said teeth 7, a free space being thus provided between the rollers 4 when in proper'engagement with the runway 5, and the teeth 7,. Furthermore, the beveled end of each roller 4, and likewise the correspondingly shaped end wall 5 of the runway '5, commences in its extent or formation from a point opposite the base cal drum having peripheral runways near a its ends, each provided with a beveled side in combination with rollers supporting said one of said redrum having interior lifting and deflecting blades extending substantially in the direction of the beveled contact ofi said rollers with said runways. p

in testimony whereof I ,aflix my signature.

' Enron H. trcnrnnnnne.

gaging a beveled side of ed face ent

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