US2527538A

US2527538A - Concrete mixer

Info

Publication number: US2527538A
Application number: US689632A
Authority: US
Inventors: John D Farrell
Original assignee: FOOTE Co Inc
Current assignee: FOOTE Co Inc; FOOTE COMPANY Inc
Priority date: 1946-08-09
Filing date: 1946-08-09
Publication date: 1950-10-31
Anticipated expiration: 1967-10-31

Description

J. D. FARRELL CONCRETE MIXER Oct. 3l, 1950 2 Sheets-Sheet l Filed Aug. 9, 1946 J. D. FARRELL CONCRETE lvlxER Oct. 31, 1950 2 Sheets-Sheet 2 Filed Aug. 9, 1946 I 71 vez? For Patented Oct. 31, 1950 CONCRETE MIXER John D. Farrell, Nunda, N. Y., assignerY to The Foote Company, Inc., Nunda, N. Y., a corporation of Delaware Application August 9, 1946, Serial No. 689,632- 3 claims. (011259-161) This invention relates to concrete mixers ofv the type embodying plural or double drum constructions in which the concrete aggregates are irst introduced into one mixing drum or cham- Yber and partially mixed therein and thereafter transferred to a second mixing drum or chamber wherein the mixing operation is completed, the mixed concrete aggregates being nally discharged from the second drum or chamber. More particularly, the invention relates to improvements in the mechanism for transferring the aggregates from drum to drum and for discharging the fully mixed aggregates from lthe second drum or chamber.

One of the principal objects of the invention is to provide a simple and effective joint mounting for the separately operable transfer and discharge chutes which effect, respectively, the transfer of the aggregates from the first to the second mixing drum, and the discharge of the fully mixed aggregates. Y

Another object is to jointly support such separately operable transfer chute and discharge chute from available stationary parts at opposite end openings of the double drum structure.

Another object is to provide such an aggregate transfer and discharge mechanism for a double drum mixer which avoids the necessity for special sealing means between the mechanism and the transfer and discharge openings of the doubl drum structure.

Another object is to provide such a mechanism in which the transfer chute control is arranged to extend through the inlet end opening of the double drum structure, and in. which the discharge chute control is arranged to extend through the discharge opening thereof, and in which both controls are directly ,coupled tothe respective chutes in a simple, strong and positive manner and .Without interferences with the mixing, transfer or discharge operations.

Other objects are to provide such a transfer and discharge mechanism which is simple and strong andwhich will stand up under conditions of severe and constant use without getting out of order or requiring repairs.

Other objects and advantages will appear from the following description and drawings in which Fig. 1 is a fragmentary vertical section through the double drum of a double-drum concrete mixer and showing the aggregate transfer and discharge mechanism embodying the presentinvention.

Fig. 2 is an end elevation of a double drum shown in Fig. 1 and viewed from the inlet end thereof.

Fig. 3 is a vertical transverse section taken on .line 3--3, Fig. 1.'

The double drum, indicated generally at 5, is

mounted for continuous rotation about its axis and is driven in the, direction of the arrows as,- sociated with Fig-3 by any suitable means, the mounting and driving means for the double drum forming no partof the present invention and hence not being shown. The double drum is shown as comprising a cylindrical steel shell 6 provided at its inlet end with a frusto-conical end head 8 terminating in a ring 9 which forms an inlet opening I0, theseparts being Welded or otherwise secured together. the cylindrical shell 6 is provided with a frustoconical end head I2 terminating in a ring I3 which forms a discharge opening I4, these parts like-wise being welded or otherwise secured together and the ring I3 having an inwardly projecting annular flange Ivi-which surrounds the discharge opening I4.

Y At its center the cylindrical shell is provided with an annular partition I6 which is welded at its periphery to the inside of the shell and which divides the shell into a rst mixing compart- Vment or chamber rI8 and a second or nal mixing compartment or chamber I9. The opposite sides of thisV partition frusto-conical end heads .20 and 2|, each being arranged' in the corresponding compartment o r forms a transferzopening 24 which is concentric with the axis of rotation of the double drum 5.

Each of the chambers or compartments I8', I9 are provided with an annular series of buckets or sweeps which are welded to the inside faces of the cylindrical shell 6 and the frusto-conical end heads and which serve both to lift successive increments of the aggregates in the bottom of each chamber or compartment to an elevation where they .slide off to return to the bottom of the chamber and also to` move the aggregate fin each chamber axially back and forth, thereby to secure thorough, uniform and rapid mixture of the aggregates in each chamber, as well as to d eliver the aggregate to the transfer and discharge chutes, as hereinafter described. These buckets or sweeps can be V.of any suitable form and are shown as being of two shapes or types desig- .nated at 28, 28a, arranged in alternation with At its opposite end IB are reinforced by ment or chamber I8, I9. The buckets or sweeps 28 of one type or shape are comparatively long, having a central portion 29 welded to the cylindrical shell 6 to extend at an angle or in generally helical relation thereto and end portions 30 and 3| which are arranged at obtuse angles to the central part 29 and to each other. The alternatingbuckets or sweeps 28a are 'of the same general for'm but shorter and hence the same reference numerals have been applied and dis-` tinguished by the suffix a. The

sweeps

28, 28a extend inwardly from the inside walls of the compartments as shown in Fig. Y3, and'it will ,therefore be seen that as the drum rotates in -the direction of the arrow associated with Fig. 3, each bucket or sweep picks up a part of Athe aggregates in the bottom of the corresponding compartment and lifts it to an elevation near the top ofthe drum where it falls back into the mass in a bottom of the drum. At the same time the helical angularity of the different portions of

thesweeps

28, 28a moves the amounts picked up back and forth axially of the drum, this angularity tending, however, to move the portions being elevated toward the transfer or discharge ends of the compartments so that transfer and discharge of the contents of the compartments I8, I9 can be effected, as hereinafter described.

In the inlet opening vI!) leading to the rst compartment or chamber I8 is arranged a stationary tubular intake chute 33 which is shown as carried by a stationary supporting plate 34 arranged outside of the drum structure and as extending downwardly through the intake opening I into the first mixing compartment I8. The unmixed aggregates can be supplied to this intake chute by the usual skip (not shown) or in any other suitable manner.

A gear box 35 is mounted onv this stationary intake chute 33 within the compartment I8, this gear box being fixed on this chute at the upper margin or rim of its discharge opening and in line with the axis of the double'drum structure 5. In this gear box is journaled a transfer chute supporting shaft 36, the extremity of this shaft being journaled in a blind bearing 38 and the shaft extending through a b'earingz39 protected by a gland or stuing box 4D. The transfer chute supporting shaft 36 is arranged coaxial with the double drum structure and projects toward the fer chute structure indicated generally -at 43.

This transfer chute structure is shown as cornprising a ring 45 arranged in the chamber I8 in closely tted relation to the margin of the transfer opening 24 to prevent the escape of Yaggregate therebetween and preferably flanged at its Opposite end, as indicated at 46, for strength. This ring 45.,has fixed thereto a hood 48 which projects into the compartment or chamber I9 and the extremity of this hood 48 is formed to cal extension v52 xed to the Vunderside of the 'transfer chute 5I and having fixed thereto an end 4 collar 53 to which the collar 4I is secured by the screws 42.

An axial extending collar 55 and a stub shaft 56 are fast to the nose 49 of the transfer chute structure, both being coaxial with the axis of the double drum structure 5 and being in spaced relation to each other. The stub shaft 56 is journalcd in a tube 58, bearings 59 and 66 being provided at opposite ends of this tube for this purpose.

The corresponding end of the tube 58 projects into the collar 55 and to protect the bearings 59 and 6D a stulng box or gland 6I is provided on the ,collar 55 around the tube 58.

The opposite extremity of the tube 58 is shown as having a collar 62 fixed thereto and this collar is secured, as by screws 63, to a discharge chute structure indicated generally at 43a. This discharge chute structure 43a is substantially similar to the transfer chute structure and the same reference numerals have therefore been employed and distinguished by thesumx a, the description not being repeated.

The nose 49a carries a stub shaft 65 which is arranged coaxial with'theaxis of the double drum structure 5 and isjournaled in a stationary part 66 of the mixer frame, which stationary part is arranged outside of the double drum structure 5 adjacent its discharge opening I5 and in line with the axis thereof.

As previously indicated, the transfer and dis- 'chargechute structures 43, 43a. are separately Vmovable into operative and inoperative positions.

For this purpose the transfer chute, supporting shaft 36 is provided, within the gear box 35, with a segmental gear -58 which .is fast thereto and .meshes with arcompanion-segmental gear 69 in the gear box 35 and fast to a control shaft 16. This control shaft is journaled in the gear box 35 and projects horizontally outwardly therefrom .alongside the intake chute 33 and through the intake opening I8 of the double drum structure 5. Outside of the double drum structure this control shaft TIO has fast thereto an arm II to the free end of which is -pivotally connected an operating shipper rod or link '12. v

vTo operate the discharge chute assembly 43a, an arm I5 is fast to the nose V49a of this structure to project laterally therefrom and the free end of this arm is pivotally connected to an operating shipper rod or link 16'.

In the operation of the concrete mixer as above described, it Will be understood that the control lcan be manual, or under automatic control of the usual batchmeter set in operation by the elevation 0f the skip in charging the mixer.

It will also be understood that water is introduced into the charge of aggregates, and Portland cement admitted through the intake chute 33 to the first compartment I8, either under manual or batchmeter control. The double drum structure 5 rotates continuously while the mixer is in operation. It will also be assumed that the partly mixed charge has been transferred from the first chamber I8 to the second chamber I9 for further mixing and that the first chamber is to receive a charge.

In admitting the charge of aggregate, Portland cement and water through the intake chute 33, both the transfer chute 5I and the discharge chute 5Ia are in their inoperative position, this being with these chutes arranged in a horizontal position with their concave sides facing horizontally so that any aggregates falling upon the inlet ends of these chutes fall back into the same gamas thamber:v I'8` or"|9 insteadI of"beingr conveyed by "of those, chambers. At the same time, the helical a'rrangement'and angular form of the buckets or sweeps 28, 28a operate to shift the elevated increm'ents backand forth axially of the compartments to further insure intimate and uniform admixture thereof. I When the mixture of the charge inthe see compartment I9 has been completed, the dis- Vfeha'rge chute l43a is rendered operative to disharge the mixture therefrom. 'For this purpose Ythe controlshipper rod or link 'i6 is actuated to `loscilla'te the arm 'I5 fastto the nose-49a of 'the fdischarge chute structure 43a and so as to rotate the discharge chute 5 Ia of this structure 90 from its horizontal inoperative position' assumed to its `vertical operative position shown in Fig. l.v In so llmoving, the discharge chute structure rotates in 'the bearing provided for its stub shaft 65 in the stationary' frame part 66 and on the bearings .60' and 59 which journal its tube 58 on the stub'shaft 56 fof the transfer chute structure 43. As these bearings are coaxial with Vthe axisof the double drum structure 5, the discharge chute 5Ia is ro- Atatedabout this axis to its Vertical positionfin which its concave side faces upwardly. The 'incre` ments of the batch in the secondcompartment I9 being lifted by the buckets oi"

sweeps

28, 28a therein, thereby fall into the discharge chute -5 Ia', 4instead of falling back to the bottom of Ath'evcom- 4partmentv I9, and thence slideby gravity down this chute and out of the end discharge openin'grm., 'Y .1 ik.. i

The angular form of the blades or sweeps 28, 28a in the compartment I9 insures the rapid discharge into the discharge chute 5Ia and when this discharge is completed the discharge chute 5Ia is moved to its inoperative position and the transfer chute 5I to its operative position. In moving the discharge chute to its inoperative position the shipper rod 'I6 is moved in a reverse direction to swing the arm 15 on the discharge chute assembly 90 and rotate the discharge chute structure 43a in the bearing for lts stub shaft 65 and on shaft 55 so as to bring the discharge chute Slal to a horizontal position in which its concave side faces horizontally and hence is incapable of receiving and conveying the increments elevated by the buckets or

sweeps

28, 28a. In moving the transfer chute 5I to its operative position the shipper rod 12 is actuated to rotate the arm 'II and control rod 'I0 a predetermined distance. segmental gear 69 fast to this control shaft and the segmental gear 68 fast to the transfer chute supporting shaft 36. Thisvrotates the transfer chute structure 43 about the axis of the double drum structure 5, this structure rotating in the

bearings

38, and 60 and 59 provided inthe stationary gear box 35 and in the tube 58 of the discharge chute assembly, respectively. This rotation of the transfer chute structure 43 is.90

so as to bring its chute 5I from the horizontal .1:

This rotates the 53 l`ipprative Avposition to the -Vvertical position Ashown? in Fig; 1, in which its concave side faces upwardly to receive the increments falling from l the buckets or 'sweeps 28,y 28a in the first compartmentfl, these received' increments sliding dWhthisfP-transfer chute into the second compafrtment I9. f f j, "fterthe partially mixed aggregate' h'asbeen so discharged from the first compartment -I8, the-shipper rod 'I2 is moved in a reverse direction -toretiirnthe transfer chute 5I to its horizontal inoperative position,A the parts thereby being in thelconditi'on rst assumed and the cycle being `repeated by the introduction of another charge cf-'aggregate, Portland cement and water through theintake chute 33 into the first mixing com- -rtment is;l Y

From fthe foregoing itwill be seen that the presentfinventionprovides a very simple, sturdy arid-gamplyv Iprotected mounting for the'transi'er 'and discharge chute structures, and which permi@ their independent operation, this mounting V being:achievedv byA the mutual support kprovided f the stub shaft 56 provided on one of these 'structures and journaled in the tube 58 provided .by the' other of these structures and by the sepa--l rate end bearings for these structure provided fin the stationary parts 35and 66 adjacent'the oppositeend openings of the double drum struc'- ture v5.

I claimri f 1 ,'In' a concrete mixer having a rotating mix- 'ir1 g drum"'provided with an intake opening at v'o eendgja discharge opening at its opposite end; ntral transverse partition dividing said drum 'into'a first compartment adjacent said intake t:opening and""a' second compartment adjacent 'said'disch'arge' opening and having a transfer ,c'rfnenir-ig'aiming with said intake anddischarge openingsfand ,meansi for elevating increments of the batchjin each compartment to a place near 't top, thereof and permitting them to fall, the :combination therewith of means for transferring the, batch of aggregate from said rst to said second compartments' and from `said second com-'- partment through said discharge opening, comprising a transfer chute arranged in said first compartment at an angle to the axis thereof and rotatable about said axis to a position to receive said falling increments in said first compart-r ment and to conduct them through said transfer opening, a discharge chute arranged in said second compartment at an angle to the axis thereof and rotatable about said axis to a position to receive said falling increments in said second compartment and to conduct them through said discharge opening, means at said axis of said compartments rotatably connecting said chutes and holding them against angu- 'I lar displacement with reference to said axis, comprising a stub shaft rigidly secured to one of said chutes and journaled in a tube rigidly secured to the other of said chutes, said tube and stub shaft being coaxial with said axis, a stationary journal adjacent said intake opening and supporting the corresponding end of said trans- 'fer chute to rotate about said axis, a stationary transverse partition dividing said drum into a first compartment adjacent said intake opening and a second compartment adjacent said discharge opening and having a transfer opening alining with said intake and discharge openings and means for elevating increments of the batch in each compartment to a place near the top thereof andv permitting them to fall, the combination therewith of means for transferring the batch of aggregate from said first to said second compartment and `from said second compartment through said discharge opening, comprising a transfer chute arranged in said first compartment at an angle -to the axis thereof and rotatable about said axisto a position to receive said falling increments in-said first compartment and to conduct them through said transfer opening, a discharge chutearranged in said second compartment .at an angle to the axis thereof and rotatable about said axisto a position to receive said falling increments in said second compartmentand to conduct them through :said discharge opening, means at said axis of said compartments rotatably connecting said chutes and holding them against angulaidisplacement with reference to said axis, comprising a stub shaft rigidly secured to said transfer chute and extending into said second compartment and journaled in a tube rigidly secured to said discharge chute, -said tube and stub shaft being coaxial with said axis, a stationary a discharge opening at its opposite end, a central l transverse partition dividing said drum into a rst compartment adjacent said intake opening and a second compartment adjacent said discharge opening and having a transfer opening alining with said intake and discharge openings and means for elevating increments of the batch in each compartment to a place near the top thereof and permitting them to fall, the combina tion therewith of means for transferring the batch of aggregate from said first to said second compartment and from said second compartment through said discharge opening, comprising a, transfer chute arranged in said first compartment at an angle to the axis thereof and rotatable about said axis to a position to receive said falling increments in said first compartment and to conduct them through said transfer opening, a discharge chute arranged in said second compartment at an vangle to the axis thereof and rotatable about said axis to a position to receive said falling increments in said second compartment and to conduct them through said discharge opening, means at said axis of said compartments rotatably connecting said chutes and holding them against angular displacement with reference to said axis, comprising a stub shaft rigidly secured to one of said chutes and journaled in a tube rigidly secured to the other of said chutes, said tube and stub shaft being coaxial with said axis, and a stuingbox between said stub shaft and tube, a stationary journal adjacent said intake opening and supporting the corresponding end of said transfer chute to rotate about said axis, a stationary journal adjacent said discharge opening and supporting the corresponding end of said discharge chute to rotate about said axis, and means for separately rotating said chutes about said axis.

JOHN D. FARREIL.

REFERENCES CITED 'I he following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 966,869 Stocker Aug. 9, 1910 2,135,436 Ball Nov. 1, 1938 2,167,243 Lichtenberg et al. July 25, 1939 2,282,467 Faber May 12, 1942