US1781549A - Control mechanism for concrete-mixing apparatus - Google Patents

Description

NOV. 11, 1930. O JOHNSON ET AL CONTROL MECHANISM FOR CONCRETE MIXING APPARATUS Filed March 11. 1929 6 Sheets-5heet l mm m6 w 0mm w VHAVA n d R GMW we .7 cw W P NOV. 11,v 1930. JQHNSCN ET AL 1,781,549

CONTROL MECHANISM FOR CONCRETE MIXING APPARATUS,

Filed March 11, 199

-6 Sheets-Sheet 2 INVENTORJ 001/52 JOH/l/d'O/V BY Ray/vamp 4 SA/vases M fl/ Nov. 11, 1930. O JQHNSQN ET AL CONTROL MECHANISM FOR CONCRETE MIXING APPARATUS Filed March 11 1929 6 Sheets-Sheet f l I I I ll HIM" NOV. 11, 1930. O JOHNSON ET AL CONTROL MECHANISM FOR CONCRETE MIXING APPARATUS Filed March 11, 1929 6 Sheets-Sheet 4 6H 2 mww v W WJW ww T Nrv H d w w? QM Nov. 11, 1930. O JOHNSON ET AL 1,781,549

CONTROL MECHANISM FOR CONCRETE MIXING APPARATUS Filed March 11, 1929 6 Sheets-Sheet 5 ATTUMEYS' NOV. 11, 1930. O JOHNSON ET AL Filed March 11 1929 CONTROL MECHANISM FOR CONCRETE MIXING APPARATUS 6 Sheets-Sheet 6 //7//////////I/////////////fl 11v VENTORS OLIVE/P dorm 60M PAD/MONO G demos/es M i?/ f n I4 TTOR NE Y5 Patented Nov. 1 1 I930 OLIVER 'JOHNsON,

mm -sime srOKANE, wAsnrNG'rON CONTROL MEcnAN sM m, cONoRErnixmeAPPARA US Application filed Marchil, 192a, seri a1No.,345,949.

the drum were revolved until they were considered to be sufiiciently mixed, which was determined by mere visual inspection. accordance with this method the concrete produced frequently did not satisfy the .required tests, for, it the mixing period, was

' too short, the concrete would contain an excess of cement in some portions and [an in.- adequate supply of cement 1n other portions;

011 the other hand, if the time of the mixing period was above the time normally required,

considerable labor would be wasted in waiting for the supply of wet concrete, and the full efiiciency of the, equipment would not be realized.- f

Accordingly, it is an object ofour invention to provide improved means for accurate:

ly controlling the duration of the mixing operation of the ingredients, such as rock,

sand, cement and water, so as to produce con crete which-will possess the desiredqualr,

ties and characteristics, namely, uniform,

strength, durability, consistency, and to give maximum efficiency ofutilization offllabor and equipment. 7 I v 'Another object of the invention isto pros vide novel releasing means for permitting discharge of the wet concrete from the drum or mixer after the ingredientshave been mixed to the predetermined'extent, or after the mixer has made a predetermlned number of revolutlons.

More particularly, an-object of the invene tion is to provide means for controlllng the.

mixing operation by prevention or the lowering of the dlscharge chute until the mixer has made a predetermined number of revolutions, and for locking the discharge chute Heretic fore, the ingredients directed into,

in inoperative position until a predetermined mixing action has been givento theingreclients in the mixing drum. 3 Still another objector our inventionis t employ and utilize the chargingfhopper to actuate or re-set the control mechanism, whereby the mixing Operation will continue ATENT OFF CE 0F HOLLYWOOD, CALIFORNIA, AND RAXMDND G. SANDERS, OF,

for a predetermined-number of revolutions after charging andpreparatory to the discharge of the concretefrom the drum or mixer. c c I Another objectof our invention is in the provision of means for starting the control mechanism during the first revolution of the drum after charging the ingredients into said drum, andin the provision of improved aneans whereby the discharge. chute may be raised at anytime after the hopper has directed'the ingredients'intothe drumeven though the control mechanism started operating. 4

A further object'ot the invention is the provision of a control device which'may be has already made and sold as a separate unit, and which may be mounted upon, and used in connec tion with, any type of, rotating concrete m xer. c

A further object of the invention is'to provide. a control mechanism offering a simple means for varying'the duration of the mixing operation as desired. v

v Specifically, the invention comprehends the use Otnovel means for locking the dischargeich'ute in inoperative position Whereby the control mechanism actuated by the r0- tation of the drum willrelease'the chute locking means after a predetermined number of revolutionsof the drum.

Another aspect of our invention is to pro-' vide an audible signal to'notify the operator that the drum hasv made predetermined number not revolutions and that the chute locking means has been releasedto permit lowering of the chute to the delivery position.

More particularly the invention ,contemplatesthe utilization of novel means-foractuating a control member or rack whereby the latter may be advanced in travel upon each revolution of the'drum and held in the advanced position by an improved holding means.

It is to be understood that the apparatus herein disclosed is merely suggestive of a type of apparatus that may be employed in carrying out the new method of operation, it being understood that any other sultable.

apparatus may be employed within thespiri and scope of the invention.

The invention is exemplified in the com-5 bination and arrangement of parts shown in the accompanying drawings and described in. the following specifications, and it is more particularly pointed out in the appended claims. i

Referring to-the drawings:--- Big. 1 is a side view of the mixing drum mounted on a portable carriage illustrating the feed hopper and discharge chute in lowered and raised positions by full and brokenlines respectively. 7

Fig. 2 is a perspective and enlarged broken view of'a portion ofthe mechanism shown inF-ig. 1.

Fig; 3 is a plan view of the control mechanism with the top plate removed.

1 Fig. 4 is a fragmentary plan view of apart of the control mechanism.

Fig.5 is a'sectional view taken on the line 5-5 inFig. 3 in the direction of the arrows,

illustrating the compound lever in normal or line 7+7 in Fig- 3, in the direction of the arrows, with the control member at or near the outer end of its movement.

Fig. 8 is a longitudinal broken sectional view taken on the line 8-8 in Fig. 3 in the direction of the arrows, but with the control member in an intermediate position.-

Fig. 9is a view in perspectiveof the end portion of the actuating lever, shown in Figs. 2 and 5..

Fig. 10 is a perspective ,view of-one end of the re-setting rod. j

Fig. 11 is a view in perspective of the com pound lever. 1

Fig. 12 is a plan viewof the locking bar.

Fig. 13 is a view in perspective of the lockingbarshowing the latch member thereof, butin section, taken on the line 13-13 of Fig, 12 looking in thedi'rection of the arrows.

Fig. 14 isfa diagrammatic sideelevation of a modification.

' Fig. 15 is a broken plan view of the timing apparatus'of Fig. 1 1 with the top plate removed; Fig. 16 1s a sectlonal view taken on line 1616 of Fig. 15 inthe direction of the arrows, but with pinion moved to inoperative position.

Fig. 17 is a longitudinal sectional view taken on the line 17-17 in Fig. 15 in the direction of. the arrows.

Fig. l8zis a sectional view onthe line 18-18 in ;.Fig. 15 looking in the direction of the arrow Fig. l 9'is a fragmentary sectional view on the line 19.-19 in Fig. 17 looking in the direction ofthe arrows.

In accordance'with the preferred embodiment, it is proposed, to re-set the control mechanism, that is, to return the same to a starting: position,.by.the charging hopper as the. ingredients are fed into the drum, and to automaticallysound an audible alarm signal1a-fterthe drumhas made a predetermined numberof revolutions, notifying the opera torthat the chute has been unlocked by the control mechanism andnthat thechute may be manually: lowered for discharging the mined-concrete from the drum.

Referring to the embodiment illustrated in Figs. 1 to 13 inclusive, 10 denotes generally the conventionaldrum or concrete mixer rotatably sustained between the frame memhers-11 comprising a carriagesuitably mountedon axles 12-carrying the Wheels 13 so that the drum maybe moved to any preferred position. The usual means, not shown, are also provided for rotating the drum at suit able speed for efiecting the mixing operation. Suitablypivotedat 1 1- to one of the frame-members'll of the carriage, is thehopper l5- carrying cable 16 which istrained overa-drum-connected to pulley orsheave 17 preferably journaled in any well known manner-on the top of thecarriage. Gable 16-.is preferablywound;0n a cable drum (not shown) for raising the hopper to the elevated position indicated by the broken lines. he hopperl5 is provided with a transverse plate 18 :whichactuates one end of the re-setting rod1-9 for a urpose which will be hereinafter disclosed; f course, as the. hopper is lowered, the cable is unwound from the windingor cable drum (notlshown). The parts above'describediare such as are provided in the ordinary concrete mixing apparatus now in common use, and form no part of the presentinvention, although they are associated with. the operation thereof.

The resetting rod 19 extends across the carriage 1 and is preferably slidably supported within guiding collar 20 including plate 21 which is secured to the upper frame member 22 of the carriage. The rod 19 is provided with'the bushing .23 which is fixed and held rigidly on the. rod 19 by the set screw 24. Bushing 23 and-collar 20 are provided with annular plates 25 forming a bearing surface for the .coiled spring 26 which loosely surrounds the rod 19 between the plates 25.

a it followsgtherefore,that spring26 normal-Q 1y holds therod 19 out ofengagement'with' the control mechanism disposed within the casing27.

The resetting rod'19 extends inside the cas ing 27 and is provided with a lug 28 (see Figs. 5' and 6) 'which'is pivoted to said rod by pin'29. Said lug, however, engages shoulder 150 on bar 19, so that upon actuation of said bar the lug will move with it, but upon return movement of the bar the lug is free to swing about pin 29, as shown in dotted lines at '28. in Fig. 6. Rod19 is guided in its travel within the. casing bythe dependingrails 30 secured'to the underface of the cover 31. of the casing 27. Disposed between the sides of casing 27 and secured thereto by rivets 32 orthe'like, are the pair of transverse spaced braces 33 (see Figs. 3, 5, 6 and 12) comprising the enlarged portions 34 and the reduced portions 35, (see Figs. 5 and 6). Thctopfaces 36 of the enlarged portions 34 form guiding surfaces for the rod 19 while the top faces 37 of. the reduced portions 35 are low enough to provide aslight clearance beneath the pivoted lug 28 and permit free movement thereof. Arrangedv within the gap formed by the spaced transverse braces 33 is the compound resettinglever 38 pivotally supported by pin .39 carriedby the braces. The compound lever 38 comprises the normally elevated-wing or arm 40, the

inclined arm 41, and the depending unitary fiat leg member42ihaving a twist 43 merging into an integral transverse flat lug providing a relatively wide actuating portign 44 (see Fig. 11). Compound lever 38 isv provided with the-perforation 45 throughwhich pin 39 is passed and secured. to the spaced braces 33. Normally the compound lever 38 takes. the position shown in Fig. 5, that is, theinclined arm 41 abuts the stop pin 46 secured to the braces 33 while the'elevated arm 40 extends above the faces 37 of braces 33 forming an inclined angle -tl1erewith, said lever being held, in thls position by reason of the coiled spring 47, having its terminals 48 preferably secured to theflat leg as at 49 and to the bracket 50 mounted on the side of casing 27, as at '51.

.Means have been provided for slidably supporting and guiding the control member or rack 52 (F ig. 3) on the bottom wall of casing 27. To this end, said control member is providedwith a pair of perforations 53 registering with the longitudinal slot 54' in the bottom wall of casing 27. A bracket 55 (Figs. 7 and 8) mounted at one endof member 52 includes the horizontal. arm hav-;

,guided within the longitudinal slot. 54. Bolt head 58, ofcourse, slides along the under,- face of the bottom wall of theicasing, while the stud 57 extends through the perforations of the control member and 0f the horizontal arm 56 0f bracket 55 and is clamped theretoby the nut 59. At the other end of the controlmember (see Figs. 3' and 8), thebracket' is eliminated, and consequently'the locking.

nut 59"sec'u'red tothe upper end of stud5 isclamped directly to the top face of themember 52, while the head 58 of saidstud sl dably engages thebottom face of the casmg. t v

The control member 52 is provided with a serrated edgehavingteeth 60, (Fig. 3). At the other side, said control member is cutaway asshown at 61; so as to provide a reduced portion 63 and an enlarged portion 62, having a shoulder 61 therebetween. Said control memberalso has an end face 64 adapted toabut face 65 of the stop 66 when the control memberis atthe extreme right or starting position (see Fig. 3) at the beginning of the first revolutlon of the drum. The

stop 66 comprising a transverse block secured to the bottom face of casing 27 bythe. spaced be ts 67 and clamping nuts 68. Normally control member 52 is at the extreme right (as shown in Fig. abutting the stop 66, due

to the action. of the coiled spring 69 having one end 70 refiexed and secured to the stand aid 71 of the; bracket 55 aforesaid and the other end 7 2 preferably secured to thejbracket,

member and engage said teeth so as to movev the control member and the alarm actuating pin 76 thereon'towards the left upon movementof said actuating pawl in that direction;

The actuating pawl 74 is pivotally connected to the end, of a slidableofiset plate 7 7 having longitudinal guide slot 78 through which entend headed studs 79 secured to bolts 89passing through the bottom wall of the housing (see Figs. 3, 5 and 8). 'The stud heads 81.

hold plate 77 down onto the bottom wall of the housing, while permitting the same to slide thereon. The other end 82of slidable plate 77 is offset by the inclined intermediate portion 83, and rests uponthe top face of a lever 84. Said lever is suitably fulcrumed by pin 85, having a head 87 (see Fig. 5) and extending through said lever, through a spac- I ing ring orboss 88, and through the bottom of the casing 27, and provided with a nut 86. v

The actuating pawl 74, the lever 84, the offset portion 82 and the plate 89 (Figs. 3 and 8) are pivotally connected by stud 90 preferably having its lowerhead 91 countersunk in pawl74=and these parts are held together.

by the 'clamping nut 92.- These parts therefore move bodily. as lever 841 is actuated by pin 93 (see Figs.12 and mounted on the revolvingconcrete mixing drum 10, moving in the directionof thearrowin Fig. The lengthof guide slot 78 determinesthe length of eachmovement ofthe actuating. pawl,as hereinafter described.

Normally the coiled spring 94 which is secured to. plate 89, as at 95 and to the fixed bracket 96 mountedon the right end wall of casing 27, as at 97, holds lever 8 1 in the position shown in Fig. 3, that is, in the path ing pin 95 forming an abutment for the free end of leaf spring 96 which is secured to the intermediate portion 88 of the oifset plate 77 inany suitable manner. Normally the compression of spring 96, holds tooth 75 of pawl 74 in engagement with theteeth of the control member, but permits the end of said pawl toslide back over said'teeth during the backward movement of the pawl.

For locking the controlmember 52 in its advanced position upon each revolution of the drum, a holding pawl 97 is provided having the terminal tooth 98 normally held between teeth 60 by the action of leaf spring 98 (shown in Fig. 3 but removed in Fig. 8)

having its free end abutting pin 99 on the pawl. The other end of spring98 is coiled or reflexed about pin 100, preferably secured to casing 27 and is supported by the supplemental fixed pin 101 likewise held to the casing in any prefered manner. Holding pawl 97 is preferably pivoted to the lower wall of casing 27 by the bolt 102 having its shank extending through the pawl and the casing and being clamped by the adjustable nut 103.

Referring to Fig. 4:, it will be apparent that as the control member 52 is advanced to the left by tooth of the actuating pawl 74;, tooth 98 of the holding pawl 97 will ride over a tooth of the rack 52 originally locked by said holding pawl, prior to the operation of the actuating pawl 7 4. As disclosed, the length of slot 78 is such as to provide for movement of controlmember 52 through a distance suflicient to cause passage of one tooth beneath the holding pawl 97 and permit said pawl to enter between that tooth and the next, so that, upon each revolution of the drum 10, the control member is advanced a distance equal to the pitch of the teeththereon; but it is within the scope, of the invention, to change. the length of said slot, or the position of said stud, and to alsovary the leverage of lever 84: if desired, so that the control member 52 maybe moved a distance corresponding to' the width ofanynumber of teeth, or a'distance cori1espending to any; desiredfraction of its total, movement, upon eachrevolution of the 1mmv ing drum.

Mounted on lever8et at the outer-end thereof is the yieldable finger 104 which is pivot ally secured thereto by the rivetor the-like 105. Said finger 104;. (as shown particularly in Figs 3 and 9) is provided withxan arcuate or inclined end face 106. andJincIudes the depending side abutment: 107 forming .aa shoulder. engaging the side oflever '84; The spring 108 (Figs. 3and5) whichlis secured to abut= ment 107 and toaarbracket 109fixed to lever 8 1; normally holds finger 104' in alignment with lever 841, with abutment 107 normally in contact with the outer face o frthe lever.

Spring 108 is relatively strong, so that-as long as the pawl-74 is freeto move, engagement ofpin93 withfingerr104: will cause said finger and lever 84 to movebodily, advancing the control member 'asabove described How.- ever, when said pawl is stopped bywengagement of the end of slot 78with stud 79 as above described, spring 108 will yield suflicientlyto permit'finger 10 1 to 'swings'about its pivot 'unt1l'p1n 93 passes-over and releases said finger. Spring 108 then returns said finger to normal" position, while-spring 94; returns lever 8 1 and pawl 74 to their initial position.

The discharge =chute1l8, shown in lowered or discharging position inFig. 1, and inraised or non-discharging-position in-Fi'g. 2, is se-' cured by lugs 117 to'a shaft rotatably supported on bearing brackets 116 secured tothe frame members 11, and-is-provided witha hand-lever 119 for operation thereof to either of the above'positions. Said discharge chute is preferably so mounted that it will tend to remain ineither discharging or non-discharging position when moved to such position, so

that the actual movementthereofto either positi'oirmust be effected by the operator. By means of our control device, however, said chute is prevented frombeing lowered to discharging position duringthe mix-ing operation. For this purpose, a-rod 112, which may havean intermediate-offset 112", is c011- nected at its lower end by a short lever arm 11 1 to shaft-115 and is pivotally connected at its upper end, as at 113, to a locking bar111' extending"vertically upward into the'casing 27 and slidably guidedwithin'a guide housingformedby wall portions '122, 123, 124land 125 of bracket 126 secured-to the side wall'of the casing as by rivets 127. Said locking bar is provided'with a latch member or dog 110, resiliently mounted thereon by leaf spring 128 fastened to said rodby screw 129. Said spring tends to-hold latch member 110 forvided with an opening 121 through which lockingbar 111 passes, said opening being sufspring,13 5, the other end of said spring beiicie'nt ly large to provide a space 121' at one side of the locking bar for passage of latch member 110 on lowering of said locking bar, and a space 121 at the other side of said locking bar to permit outward movement of said latch member against the action of leaf spring 123 upon upward movement of sa d locking bar Such outward movement of the latch member is caused by the inclined face 130' thereof engagm g the face of the enlarged portion .62of control member 52 when the locking bar is raised under certain conditions, as hereinafter described. The outline of opening 121 is shown in dotted linesin Fig. 12.

Fornotifying the Operator that the drum v has made a predetermined number of revolutions and that the discharge chute is free to belowered, pin 76 on control member 52 (see Figs. 3and7) isprovided, adapted to engage lever 131 forcing the latter" to move lug 132 against which it bears,.and hence to move the bell-crank lever 133 comprising arm 134to which issecured one end of coiled ing secured to bracket 136 rigidly ,carriedby casing 27. The flat spring arm 137 also ex tends from the. bell-crank lever 133 and is provided with a clapper 137'. Lever 131 and bell-crank lever 133 are pivotally supported on pin 138 extending upwardly from the bottom wall of casing 27 and preferablysecured thereto by the locking bolt 139. For limiting the swing of the spring arm 137 upon release thereof as hereinafter described, astop pin 140 is provided projecting inwardly from casing 27, and is securedthereto at 141 in any well known manner. Normally lever 131 bearsagainst the lug 132 due to the force of the leaf spring 142. which' connec ts.said, lever with the arm 134, whilei'arm 13.7 is held I against stop pin 140 by spring 135.

Thus, it follows, that asthe'pin 7 6 strikes lever 131, the bell-crank'lever 133 is actuated 'in a counter-clockwise direction (in Fig. 3), and accordingly retracts clapper arm 137 against the action of spring 135. As the pin 76 passes over and beyond the tip of lever 131, spring 135 compresses, swinging arm 134and spring. arm 137 in the reverse direction so that altho' arm 137 is arrested by stop140, the resiliency of said arm causes the clapper 137 to swing through opening 143 in the casing and to strike the gong 144 carried by theicasing, and thereby'sound an audible alarm, indicating that the discharge chute should belowered. In the return of pin 76 to the. right it will ride overthe inclined face145 of lever 131 and thelatter will yield or move against the leaf spring the hopper; rises toward the vertical, the in gredientsare fed and discharged into the mixing drum; Further movement of the hopper causes the transverse plate 18 to bear against the outerend of re-setting rod 19,

moving the latter inwardly and. causing lug 28 to depress arm 40 of the compound lever 38-.to swing the latter down to the position shown in full lines in Fig. 6, against the action-of spring 47 ,so that lug portion 44 of thecompound lever 38 strikes against pin 99 ofthe holding pawl 97 and pin 95 of the .actuating' pawl 74., Accordingly,' pawls 97 and 74,:areinoved out of engagement with the teeth of the control member 52, as

shown in full lines in Fig. 6,permitting said control member'to slide automatically to the right by the action of'spring 69, until end face 64 bears against the flat face 65 of stop 66. Th effunction of the re-setting rod 19, therefore, is' toactuate the compound lever, to release the holding and actuating pawls from the control member and allow thelatter to be re-setagainst the stopprior to the first revolution of the mixing drum following charging thereof. v I The pivoted lug 28 rides over the full length of the arm 40 of compound lever 38, and assoon as it passes beyond the end thereof,said lever isreturned byspring 47 to the position shown in dotted lines in Fig. 6. .As the charging hopperis then lowered to be reloaded, spring 26 returns re-setting rod to normal position, and in this movement the lug 28 swings upwardly about pivot 29, as also shownin dotted lines, so as to ride over arm 40 without depressing the same.

Ifthe delivery chute was already in raised ornon-discharging position, as shown in Fig.-

2 and dotted lines at 118' in-Fig. 1,- prior to re-setting of the control mechanism, the enlarged portion 62 of the, control member will be broughtbeneath latch member 110 to holdthe same in this position. f In ordinary operation, the delivery. chute should be moved .tothis raised or non-discharging po- "nevertheless begin to operate the control mechanism, and the delivery chute may be raised-and locked in the same manner, at

any time'thereafter. Therefore, in any case, the control mechanism operates to cause the mixing drum to make the required number of revolutions following-eharging of the'unmixed ingredients therein, regardless of the 'time at whichthe delivery chute is raised ,to non-discharging position. This not only insures adequate mixing of every batch of concrete, but prevents any loss of time due "to the operator failing to immediately. raise thedelivery chute.

The rotation of the drum serves to mix the ingredients charged therein and it follows, that upon each revolution made, pin 93 (see "igs. 2 and 3 will strikeand pass thetripplng finger 104, consequently moving the actuating lever 84 to. the right in Fig. 3, so that tooth 7 5 of the actuating pawlg'r' t will move the control member to the letter away from the'stop 66. The holding pawl 97 prevents the retraction of the control member as heretofore set forth. The same operation continues at each revolution until the cut awayportion 61 of the control member: comes under thelatch member 110 of the chute-locking bar 111. The control member has at this time advanced to a position furthest away from the stop 66and atthis position also pin76 on said'control member actuates lever 131 so that clapper 137 swings through aperture 1%l3 'to strike the ..gong 14A sounding an audible alarm, indicating that the ingredr for. the reason that there areno more teeth on j the samev for the actuat ng pawl to engage.-

Until the charging hopper-again resets the control member, the pawl 74is still actuated at each revolution of the mixing drum, but

the control-member cannotadvance further. The operator -nowwlowers the dellvery chute latch member 110 on lockin ibar 111 to pass through the cut away portion ofthe control member and through opening 121 to'aposition below casing 27 as shown in-F 6.

After the-supply of mixed concrete in the drumrhas been discharged through chute 118 or while it is being so discharged, the charging-hopper is again raised to introduce a fresh batch of materials, and the timing mechanism is re-set as before. 7

Referring to themodification disclosed in Figs. i l to 19 inclusive, there is illustrated a control device cooperating with a concrete drum mixer whereby the ingredients fed into the drum are permitted to commingle or mix a predeterminednumber of revolutions, the control device comprising essentially a slida slidable ccntrol member, by engagement with a rack thereon, from the starting'or set ting position at the beginning of thefirst revolution of the drum until the control mem-i ber has reached the limit of 1ts travel, during which time the drum has made a predeternumber of revolutions; and at the .ill of he travel or stroke of the control member, the latter actuates automatically an audible alarm, notifying the operator, that the chute has beennnlo'cked by the control device to permit the mixed wet concrete from the drum to be delivered or discharged by manu ally lowering the delivery chute.

' The apparatus illustrated consists as before of the mixing drum 10 (see Fig. 14) suitably mounted on wheels 11 and provided with rotating means and with means such as above described for charging the ingredients into the drum and'for delivering the mixed concrete therefrom. Drum 10 is provided with brackets 212 fixed on its circumferential surface, adapted to actuate radially disposed arms 21% of spider 215 which is rigidly-secured to the timing shaft 216suitably journa ed insides 217 and 218 of casing 219 conining the control mechanism. I Longitudinally disposed in spaced relation and preferablyrigidly secured to the bottom wall 221 ofcasine; 21 9 by the outwardly extending fianges220 by means of the setscrews 222 or the like, is the pair of supporting bars forming for the control member 225 includln on its upper face a plurality of teeth .226comprising a rack, generally denoted' by 227. The rack, of course, is an integral part .of the control member 225, and the latter "is well known manner.

The control member 225 is provided with a longitudinal groove 230 adapted to lock v the dependinglug 231 of dog or latch 232 118 by aotuatin flhandle 119 which causes having the inclined upper face 238 and arflat outer face 234 to which is connected flat leaf. spring 235-secured to the reciprocating ,chute-locking bar236. Bar 236 is, of course,

connectedto, and responsive to the raising and lowerlng of, the discharge chute (not shown) in the same manner as the chute any time even though the control mechanism has been started. The supporting andguidmg members 220, 223, 224, 228 and 229 at this side. of the control member a'realso cutaway at the position of the locking bar, as shown in Figs. and 18, so as not to interfere with 223 having inwardly disposed fiangesf22l i ably mounted on an end wall of the casing.

232 in registration with groove230' of the slide bar 225, consequently locking thechute until said control member has reached the limit of its stroke, as will be more fully hereinafter set forth.

The control member 225 is provided at one end (see Fig. 17) with a bracket 239 suitably fixed thereon having the depending arm 240 to which is secured one terminal 241 of the coiled spring 242 disposed under the control member,'while the otherterminal 2430f the spring242 is secured to an eye 244 prefer- Coiled spring242 serves to return'the control member to the starting position, namely, the position shown'in Fig. 17, against a stop member 299 attheextreme left of the casing. It will be noted "that the control member 225 includes the cut away portion or elongated notch 245' (Fig-15) which comes under the latch 232 when said control member has been -moved to the right a distance corresponding to a predetermined number of revolutions made by the drum. I

' Suitably mounted within the casing 219 is the transverse rod 246which is mounted to slide through the longitudinal sides 217 and 218, in bushings 247 and 248 respectively; Preferably rigidly; and adjustably secured to rod 246 is the collar 249, as by means of set screw 250. r The collar 249 is provided with a tapering extension arm 251 whose outer end 252 is adapted to actuate the pinion and retaining pawl as hereinafter described.

Disposed between the transverse rod 246 and the shaft 216 is the guiding rail 253 comprising an elongated bar having horizontal offset top faces 254 and 255 connectedby the inclined. shoulder 256 (Figs. 15 and 16).

The rail. 253 is secured to the wall 218 of casing 219 by the flange 257, by means of the screw 258. Normally arm 251 rests upon the horizontal face 254, that is, before slidable rod 246, has been actuated by the hopper (not shown). It will be understood that rod 246 performs the function of re-settingthe control mechanism, in the same manner as the rod 19 of'the apparatus first described, and that it may be similarly mounted above the mixing drum in position to be engaged and forced inwardly upon raising of the chargging hopper, and also ,that'a spring, corresponding to the spring 26 of the othe'r modification, maybe provided for returning said rod to 'normalor retracted position.

The shaftis provided with a longitudinal key-way 259 (see Fig. 19) in which key 260 is held, so that the pinion 261 is slidable on the key but rotatable with shaft 216. Said pinion engages the teeth'of rack 227. Straddling pinion 261 is the cage 262 comprising an open frame having side members 263 loosely surrounding shaft 216 and integrally connected by 'thecross strap 264 and includ-;

ing tapered downward and outward extensions. connectingpawl' member 266 engaging rack227so as to form a retaining element for the control member. 1 I i For normally maintainingthe pawl 266 in lockingfengagement with the rack, a coiled spring 267 is provided surrounding shaft 216, and is secured to one of the side members 263 at 268 and to the side wall 218 of the timing casing at 269. "Said spring not only serves to normally-hold the'pinion26l and pawl 266 from side wall 18 and in alignment wlth'the rack, but also eXerts a rotational force on the cage'262tend1ng to hold said pawl downwardly intoengagement between the teeth of said rack; The longitudinal increment OfSELld pinlon and pawl,- under the action of saidzspring, is limited by ongagement of key 260 with the: end of keyway 259. Cage 262is also provided with a lateral extension arm 270 which-is a-t-a level slightly below the face255 of rail 253, for a purpose hereinafter explained.

When the control member 225 has been moved the complete length of its stroke corresponding 'to a predetermined number of revolutions of the drum, that is, when it is atits ertreme right hand position, the cutaway portion245 thereof isfbrought into position beneath latch 232, so as to unlock the chute. At the-same time, a pin 271 on the control member comes in contact with tip 272 of lever or dog 27 3 which abuts lug 275' extending from lever 276. D0 273 lever 276 are both pivotally mounted on pin 277. EX- tending. from the lever 27 6 is a flat spring 2117111278 to which is secured at its free end clapper 279 adapted to pass through opening 280 of the casing and strike the gong 281 secured to the casing to sound an'audible alarm. It will be noted that dog 273is provided with the arcuate face 282, to permit pm 271 to oass b u on the return of the control member to'the starting position. Lug 275' abuts the leaf spring 283 which is secured to the casing at 284. Secured to the spring arm 278 is the leaf spring 285 which 1s adapted to engage pin 286 extending from dog 273, so as to normally hold said dog against lug 275,. Leaf spring 283 normally holds the spring arm 278 in engagement with stop pin 287. I

he operation of this form of control mem her is as follows :Assu1ning first, that the controlmember 2251's att ie extreme right and. that the hopper (not J m) has been charged with the proper materials to l e deorcd into the drum. The re-s mechanism isJaccompli-shedupon i V hopper to ahut and more or share rod n the bearings 2 l7 and Collar 24:9 andwirm 2551;:are thus movedto the right in: Fig 16, so tht theiouter end oi said .arinz abut 'cagew262, 1no the latter and thep 261 outwoi engagement with the rack 227 deco pl ig,v Consequently the control inembor :o'nce slides Ibael; on rails to the starting or setting -position, as a r sult of .the contraction of the coiled spring 2422. However, the hopper continues to be 'el vated, portion 252 of arm 251 rides along the inclined shoulder 256 and onto the hori- -zontal face255 of the rail253, to the position vii",

indicated by the dotted lines at 252 in Fig. i '16,;and as theport1on 252 rides up on the inclined shoulder 256 it passes over the roan it; ed uppercorner 268 of side member 263 oi cage The/ latter is then returned by spring 267, to bring pawl 266 and the pin on 261 backinto position of engagement with the rack 227, due-to the action of spring 267. i The delivery chute may, as before, he raised to non-discharging position at this time, or at any time thereafter, spring 235 yielding as above described to permit latch member 232 to pass the side of control memher 225 and into locking position.

The drum is rotating, and upon the first revolution after the control member has been re-set, bracket 212 will strike an arm 21.4 of

' spider 215 thereby-actuating shaft 216 which in turn will rotate pinion 261 to. cause the control member to move to the right a dis tance corresponding to the angular distance between arms 214. {As the pinion advances the control member, pawl 266 engages the rack to lock the same in advanced position,

engaging between the teeth 226 in advance of the pinion and thereby preventing retraction of the control member. The same cycle continues'until latch 232 registers w "h notch 245, after which the delivery chute may be lowered to discharging position. At the same time, the gong 281 is struck, due to engagement of pin 271 with dog273. Said pinfirst moves said dog forward, which engages lug 275 to swing lever 276 and spring .a'rm 278 in a counterclockwise direction (in F 15), but as the pinpasses over the the of dog 273, said jlever returns and strikes stop 287, while spring arm 278 continues its movement; causing clapper 279 to strike gong 281.

WVhen the audible signal has struck, the chute is lowered, consequently moving the locking bar 236 and latch through opening 238 in the casing. As the drum revolves, thecharging hopper of course is heun ormity.

It is evident that, in either of the forms of the invention. above described, the duration otthe mixing period may readily be varied. example, the stop plate 66 of the first form, or stop plate 299 of the/second form, may be made in a number of different lengths, so that by interchanging saidplatea,

lie length. of stroke of the control member may be varied, so as to cause the mixing drum tomake any desired number of revolutionsbefore unlockin of the dischar e chute by said control member. I Fromthe foregoing description, considered in connection with the accompanying drawings, it is believed that the several novel structural features of our present improvement as well as the advantages thereof will be readily appreciated and it will be obvious to those skilled in the art, after an understanding of our invention that other changes and modifications may bemade Without departing from spirit and scope of our invention and it is proposed in Q the appended claims,to cover suchchanges and modificz tions as are within the scope of the invention.

We claim:

In combination with a drum for mixing concrete and with a charging hopper and a discharge chute therefor, a control mechanism associated therewith comprising a casinghaving a control member slidably disposed therein, a stop at one end of said casing, means tending to hold said control member against said stop,.a holding member carried by the casing normally locking said control member against movement toward said stop, an actuating member disposed within the casing and responsive to the rotation of said drum for moving said control member away from said stop, and means responsive to the raising of said hopper for releasing both. said holding member and said actuating member, to permit return of said control member against said stop.

2. In combination with a drum for mixing ;-concrete and with charging hopper and a discharge chutethe'refor, a control mechanism associated therewith comprising a casing having a control member slidably disposed therein, a stop at oneend of said casing, means tending to move said control. member against said stop, a holding member normally locking said control member against movement toward said stop, an actuating member mounted within the easing and responsive to the rotation of said per for releasing'both said holding member and said actuating member to permit return 01" said control member against said stop. I

3. In combination with a mixing drum and with a charging hopper and a discharge chute therefor, a control mechanism associated therewith comprising a casing having a control member slidably disposed therein, a

stop at one end of the casing, means tending to move said control member toward and against said stop, actuating means operable upon each revolution of the drum for moving said control member a predetermined distance away from said stop, and locking means connected to said chute and adapted to engage said control mechanism to lock the chute in inoperative position, saidcontrol member being provided with a cut away portion adapted to register with said locking means and release the same, for unlocking said discharge chute, after a predetermined number of operations of said control member by said actuating means.

4. In combination with a mixing drum and with a charging hopper and a discharge chute therefor, a control mechanism asso ciated therewith comprising a casing and a control member slidably mounted therein, a stop carried by the casing, means tending to move said control member toward and against said stop, holding means extending from said chute and adapted to be locked by said control member, means for advancing said control member away from said stop upon each revolution of the drum, and means for releasin said holding means from the control mem er after the drum has made a predetermined number of revolutions.

5. In combination with a mixing drum and with a charging hopper and a discharge chute therefor, a control device associated therewith adapted to be set by said hopper and comprising a casing including a stop and a slidably disposed control member abutting said stop, a locking bar extending from said chute and having a resilient plate secured thereto carrying a latch member having an inclined face extending beyond the bar and adapted to move in alignment with the bar in raising the chute after the timing device has been set, said resillent plate being adapted to yield and permit sald latch member to ride over said control member and to be locked thereby.

6. In combination with a rotatable drum for mixing concrete and with a charging hopper and a discharge chute therefor, a control mechanism associated therewlth comprising stop means, a control member mounted to slide between a position against said stop and a releasing position removed.

from said stop by a definite distance, means tending to move said control member toward and against said stop means, a holding member normally engaging said control member to hold the same against movement toward said stop means, an actuating member normally engaging said control member and operable to move the same from position against said stop means toward said releasing position, means operable upon rotation of said mixing drum to cause said actuat ing member to move said control member a definite portion of the distance between said positions upon each rotation of said drum, locking means connected to said discharge chute and movable, upon movement of said discharge chute to non-discharging position, to position to be engaged and locked by said control member when the latter is in any position other than said releasing position, said control member being adapted, upon reaching said releasing position, to release said locking-means and permit movement of said discharge chute to discharging position.

7. An apparatus as set forth inclaim 6,.

and comprising in addition, means responsive to movement of said charging hopper

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