US2147575A - Timing device for mixers - Google Patents

Description

Feb. 14, 1939. A, GUEDEL TIMING DEVICE FOR MIXERS Filed Feb. 15, 1936 s Sheets-Sheet 1 3 Shgets-Sheec Feb. 14, 1939. A. GUEDEL TiMING DEVICE FOR MIXERS Filed Feb. 15, 1955 Feb. 14, 1939. L. A. GUEDEL TIMING DEVICE FOR MIXERS 5 Sheets-Sheet 3 Filed Feb. 15, 1936 mllllll' [cu/5 RG'UE EL.

l5 minimum extent.

Patented Feb. 14, 1939 w UNITED STATES PATENT OFFICE THWING DEVICE FOR MIXERS Louis A. Guedel, Indianapolis, Ind., assignor to Hetherington & Berner Inc., Indianapolis, Ind., a corporation of Indiana Application February 15, 1936, Serial No. 64,130 15 Claims. (01. 259-163) It is the object of my invention to produce a The mixer I shown in the drawings is of the timing device for regulating the operation of a pugmill type and has one or more rotatable shafts mixing machine whereby to insure that mixing ll carrying blades I 2 by means of which maoperations will be continued for a predetermined terial in the mixer is agitated. While I have length of time. More specifically, it is my object shown a mixer of this particular type, it is to to produce a timing device for controlling the be understood that my inve t n y he s d operation of a mixer used in the production of with mixers of other kinds. bituminous paving compositions, the timing de- Associated with the mixer I0 is suitable chargvice operating to insure that the aggregate will ing m ns, e e shown as an aggregate We lo be mixed dry for a predetermined length of time bucket l5, having a discharge valve l6, and a 10 before the addition of the liquid bitumen and that bitumen We u e having a sc a e after the addition of the bitumen the two invalve l8. The mixer is shown as having in its gredients of the paving composition will be mixed bottom a sliding d scharge gate H! which may together for a second period of predetermined Co ve ently be opera e y fluid p s r To this end, the gate is provided with a cylinder 20 A further object of my invention is to produce receiving a t a y p s 2| m unted on a a timing device which may readily be associated rod 22 on which the cylinder is slidable. The rod with mixers of different construction, and which s p OV ded With tWO IO IgitudinaIIY nd n can be easily and quickly adjusted to alter the p s s whi h p n in the cylinder n pp length of each mixing period as may be desired. s te s s O the Piston 2| and which commllhi- 20 In carrying out my invention I associate with Cate respectively With p p s 23 and 24 leading to the mixer suitable charging means, such as su ta a v 25 by t e Operation of which weigh-buckets for the aggregate and bitumen reeither o e pipe 3 end 24 ay be o nected spectively, each of such buckets being provided t a lu d upp y line 2 while t th r is onwith a valve or gate controlling its discharge into nested an exhaust line 27. 5

the mixer. The timing device, which is conveni- As shown. the three Valve i8, and 25 are ently driven from the mixer, is so associated with manually operated, the valve l6 having an operthe charging means and the discharging means ating handle 30, the valve I 8 having an operatof the mixer as to insure that no bitumen can be ing handle 3|, and the valve 25 having an operadded to the mixer until the expiration of a preating handle 32. Each of the valves has associ- 0 determined dry-mixing period following the adated with it a lock of any convenient form conmission of the aggregate and also to insure that trolling its operation. In the construction shown the batch can not be discharged from the mixer in Figs. 1, 2, and 3, the locks are shown as directuntil the expiration of a predetermined wet- 1y associated with the valve-operating members,

.35 mixing period following the opening of the b1- but this is not at all essential tumen valve. I may so construct the device as As shown in Figs. 1 and 3, the operating hanto provide for two wet-mixing periods of prededie 0f the aggregate Valve is p v ded W termined extent separated by an interval in which an a u me 35 p d a j c swinging additional aggregate is supplied to the mix. Segment 36, which, when disposed below the 40 The accompanying drawings illustrate my inabutment Will prevent that downward V 40 vention: Fig. 1 is an end elevation of the mixment of t e handle 30 Which is e s y t ing plant, showing the mixer, the bitumen and pen the valve IE but whi h, in its normal posiaggregate weigh-buckets, and the timing device; tion, is disposed at one side of the path of down- Fig. 2 is a front elevation of a timing device with ward movement of the abutment 35 so as not As? its cover removed; Fig. 3 is a fragmental end to interfere with opening of the valve [6. The

elevation of the timing device with a slight modisegment 36 is shown in Fig. 1 as swingable in a fication; Fig. 4 is a horizontal section on the p a e p l to the P Of movement of the lined- 4 of Fig. 2; Fig. 5 is a fragmental view handle and in Fig. 3 as swingable in a plane generally similar to Fig. 2 but showing the movperpendicular to the P Of movement 0f the ing parts in different positions; Fig. 6 is a. view handle 30; but the particular arrangement of 50 similar to Fig. 2 but showing a slightly modified the segment 3Bv is immaterial so long as it may form of timing device adapted to provide three swing into and out of position beneath the abutmixing periods of measured extent; Fig. '7 is an ment 35. The bitumen valve is shown as locked elevation of the cam arrangement; and Fig. 8 through the medium of a disk 38 which is rigid .55 is a fragmental plan on the line 8-8 of Fig. 6. with that valve and its operating handle 3| and which is provided with a radial slot for the reception of a retractable tongue 39 which, when engaged in the slot, prevents opening of the bitumen valve. The valve 25, controlling discharge from the mixer, is controlled by a disk 46 which is associated with the rotatable element of the valve and which is notched as at 4| for the reception of a locking member 42. When the locking member 42 is engaged in the notch 4|, the valve 25 is held in that position of adjustment which effects or maintains closing of the gate IS. The specific form of valve-operating devices and locks therefor illustrated in the drawings forms no part of my invention in its broader aspects, as these features are susceptible of considerable variation to meet the characteristics of the mixer and of its charging and discharging means with which my timing device is to be associated.

In the arrangement illustrated in Figs. 1 to 5, a movable control member for all the valves is provided in the form of a vertically slidable bar 56 mounted in and projecting above the top of a casing in which the timing mechanism is enclosed. Conveniently, there is secured to the bar 50 near the top thereof a rod 52 which extends downwardly outside the casing 5|. The tongue 39, which controls the bitumen-valve in the manner above setforth, is-mounted on the rod 52 to be vertically movable therewith; while near the top of the rod 52 there is provided an ear 53 having a pin-and-slot connection with the segment 36 to swing this segment as the rod 52 moves vertically with the bar 50. The bar 50 is shown as being provided within the casing 5| with a cam-slot 54 associated with which is a cam-follower 54' connected to the locking member 42 which controls the valve 25.

The rod 50 has three controlling positionsnamely, a lower position, an intermediate position, and an upper position. In the lower position, shown in full lines inFigs. 2 and 3, the tongue 39 is engaged in the slot of the disk 38 to lock the bitumen valve in closed position; but the segment 36 is out of the path of movement of the abutment. 35 on the handle 30 for the aggregate valve, and the locking member 42 associated with the valve 25 is retracted. In the intermediate position of the bar 50, shown in dotted lines in Figs. 2 and3, the tongue 39 is still engaged in the slot of the disk 38 to lock the bitumen valve closed; the segment 36 has been swung beneath the abutment 35 to prevent the downward movement of the handle 30 which effects opening of the aggregate valve l6; and the locking member 42 is extended outwardly into the notch 4| to lock the valve 25 in the position shown in Fig. 1. In the extreme upper position of the rod 56, the tongue 39 is disengaged from the slot in-the disk 38 to permit opening of the bitumen-valve l8; but the segment 36 and locking member 42 are still effective to prevent opening of the aggregate valve |6 and'any movement of the valve 25.

The control rod 50 is manually movable. Its upper and lower limits of movement are defined in any convenient manner. For example, the lower limit of movement of the rod 59 may be defined by engagement of the rod with the bottom of the casing 5|, while its upward; movement may be limited by engagement of a stationary guide 56 with the lower end of a longitudinally extending guide slot 51 in the rod. The intermediate position of the rod is. defined by a retractable stop 58 normally positioned, to engage an abutment 59 secured to the rod 50 near the mounted on the pivot member 62.

lower end thereof. A swinging latch 60 cooperating with an ear 6| on the rod 50 serves to maintain the rod in its intermediate position. The timing mechanism embodied in my device operates to control the respective positions of the stop 58 and latch 60. To this end, the latch 60 may be in the form of a swinging arm pivotally mounted upon a stud or screw 62 supported from the casing 5|, and the stop 58 may be in the form of a projection on a swinging arm 63 also Yielding means, such as leaf springs 64, normally operate to hold the latch 66 in the position shown in Fig. 5 and the arm 63 in the position shown in Fig. 2, in which positions the latch 66 is operative to engage the ear 6| and the stop 58 is positioned to engage the abutment 59.

Movement of the stop 58 and latch member 60 to their respective retracted positions is effected by two cam members 65 and 66 which are secured to a rotatable element 61 to rotate therewith, but which are angularly adjustable relatively to each other and to the rotatable element. Conveniently, the element 61 is in the form of a sleeve rotatably mounted upon a stationary stub shaft 68, as is clear from Fig. 4. Rigid with the sleeve 61 as by being integral therewith, is an annular flange or collar 69 to which the earns 65 and 66 are adjustably secured. As shown, the flange 69 is provided with an annular series of holes for the reception of bolts which also pass through holes in the cam member 65 which may be disposed against the rear face of the flange 69. In addition, the bolts 10 pass through a spacing collar 1|, a bearing collar 12, and a disk 13, which are located successively in rear of the cam member 65. The cam member 66 is rotatable on the bearing collar 12, its position relative tothe sleeve 61 being maintained by a screw 14 which passes through a slot in the cam member into any one of a series of holes 16 in the disk 13.

Secured to the sleeve 61 on the front face of the flange 69 is an arm 18 having in its outer end a stop 19 which co-operates with an adjustable abutment 80, conveniently in the form of a screw mounted in a bracket 8| on the side wall of the casing 5|, to determine the zero position of the sleeve 61 and the cam members 65 and 66 which rotate with it. As shown in the drawings, the sleeve 6"! is rotated from zero position by means of a gear 83 which is secured to the sleeve. A torsion spring 84 acting between the stationary stub shaft 68 and the gear 83 tends to rotate the sleeve 6'! in a clockwise direction to cause engagement of the stop 19 with the abutment 80.

Conveniently, the gear 83 is in the form of a worm gear and is driven from the shaft H of the mixer to which it is releasably connected through any train of driving mechanism. As shown, one of the shafts H is provided with a worm'gear 35 driving a sprocket 86 connected by a chain 87 to a second sprocket 88 which is rigidly mounted upon the end of a shaft 89 supported in suitable bearings 90 within the casing 5|. Within the casing 5|, the shaft 89 bears a worm 9| meshing with a worm gear 92 carried by a shaft 93 which is rotatably mounted in a suitable sub-frame 94. The sub-frame 94 is rocked about the axis of the shaft 89 and worm 9| to carry into and out of engagement with the worm wheel 83 a worm 95 which is mounted on the shaft 93 for rotation therewith.

When the sub-frame 94 is in the full-line position shown in Fig. 2, the worm 95 is disengaged from the worm wheel 83, and that worm wheel is therefore stationary. When, however, the subframe 94 is rocked to carry the worm 95 into engagement with the worm wheel 83, the worm wheel and the parts rotatable with it will be rotated about the axis of the stub shaft 68 under power transmitted from the shaft through the gearing and 81. 1

Conveniently, the sub-frame 94 and the parts it carries are so arranged that their center of gravity is spaced horizontally a considerable distance from the axis of the shaft 89, so that under the influence of the force of gravity the subframe will normally occupy the full-line position shown in Fig. 2, with the worm disengaged from the worm wheel 83. Movement of the subframe 94 to effect engagement of the worm 95 and worm wheel 83 may conveniently be effected through the medium of a sub-frame extension 96 which projects upwardly into association with the rear end of a push-rod 91 adapted tobe moved longitudinally of itself by a cam member 98 mounted on the bar 59.

In operation, the movable parts of the device just described normally occupy the position illustrated in Fig. 1 and in full-lines in Figs. 2 and 3. When the operator desires to mix a batch of bitumen and aggregate, he first supplies the aggregate to the mixer, as by depressing the handle 39 to open the valve I6 and empty the contents of the aggregate weigh-buckets into the mixer I9. The operator then raises the bar 59 to its intermediate position, which is determined by engagement of the stop 58 with the abutment 59. In this position of the bar 59, the latch 69 engages the tooth 6| to prevent the bar from returning to its lower position. Conveniently, there is associated with the bar 59 a bar-raising lever I99 which is fulcrumed on a bracket I 9| supported from the casing 5| and which is operatively connected to the bar 59 in any convenient fashion. A chain I92, or other flexible tension-transmitting element, may lead to the operator's station to facilitate convenient raising of the bar 59. I

Upon the raising of the bar 59 to its intermediate position, the locking member 42 is forced outwardly by the walls of the cam-slot 54 to engage the notch 4| in the locking-disk 49 of the valve 25, and the sub-frame 94 is rocked to bring the worm 95 into engagement with the worm wheel 93, all as indicated in dotted-lines in Fig. 2. The rod 52 and tongue 39 move upwardly with the bar 59, but this movement, as is clear from the dotted-line showing in Fig. 3, is insuflicient to free the tongue 39 from engagement with the slotin the disk 38 associated with the bitumen valve.

As the mixer operates, it drives the timing mechanism to rotate the gear 83 and the cam members 65 and 66 in a counterclockwise'direction. After the expiration of a predetermined interval, the duration'of which is determined by the original setting of the cam member 65, the head of the cam member strikes the upper end of the arm 63 and moves the stop 58 from its normal position above the abutment 59, as shown in Fig. 5, thus permitting further upward movement of the bar 59. The occurrence of this event is signaled to the operator as by means of a lamp I95 which is supplied with current under the control of a switch I96 conveniently arranged to be closed by swinging of the arm 63 when the stop 58 is retracted. The head of the cam 65 is so shaped as to maintain the stop 58 retracted and. the lamp I95 illuminated for ,a convenient worm wheel 83 intervalsay approximately 15 seconds. During this interval, the operator, by applying tension to the chain I92, raises the bar 59 to the limit of its upward movement, thus freeing the tongue 39 from engagement with its slot in the disk 39 and thereby permitting the operator to add bitumen to the mix by depressing the handle 3| to discharge the contents of the bitumen weigh-bucket I1 into the mixer. Upon return of the bitumen valve to closed position, the slot in the disk 39 again comes into alinement with the tongue 39, thus permitting the bar 59 to drop until the tooth 6| strikes the latch 69. As the mixer continues to operate, the cams 65 and 66 continue to rotate in the counterclockwise direction until the head of the cam member 66 strikes the upper end of the latch 69, releasing it from its engaged position and permitting the bar 59 to be returned to its lower or normal position shown in full-lines in Fig. 2. The return of the bar 59 to normal position retracts the locking member 42 and permits the operator to manipulate the valve 25 to open the dump-gate I9 in the bottom of the mixer.

As the gear 83 rotates during the mixing periods, the spring 84 is tensioned; and when the return of the bar 59 to its normal position causes disengagement of the worm 95 from the the spring 94 operates to return the worm wheel and the cams to their normal position, which is determined by engagement of the stop 19 with the abutment 89.

The duration of the dry-mix period is controlled by the position of the adjustable abutment 89, while the duration riod is controlled by the position of the cam 66 relative to the cam 65.

It is to be noted that the emptying of the aggregate bucket into the mixer mustprecede the starting of the timing device; as the movement of the bar 59 which initiates operation of the timing device swings the segment 36 beneath the abutment 35 on the handle 39 and therefore prevents opening of the aggregate valve I6 until after the timing cycle has been completed. As the bitumen valve can not be opened until retraction of the stop 58, a minimum dry-mix period is thereby effected.

It is to be noted further that the bitumen valve I8 can be opened only when the bar 59 is raised to its uppermost position and that the bar 59 can only be elevated to its upper position while the stop 58 is being held in retracted position by the cam member 65.

The modification of my invention illustrated ,r

in Figs. 6, 7, and 8 is in general intended for the same use as the modification already described;

but is provides an additional mixing period of controlled duration and also embodies a somewhat difierent means for controlling the supply of aggregate to the mixer. This modification is particularly suited to control a process in which a second quantity of aggregate, usually a fine aggregate such as limestone dust, is added to the primary mixture of aggregate and binder after the expiration of successive dry-mix and wet-mix periods.

The device of Figs. 6, 7, and 8 embodies the same vertically slidable member 59 as the other modification, and movements of the member 59 are controlled by the same latch 69 and swinging arm 63 as are employed in the othermodification. Instead of controlling opening of the aggregate valve through the medium of the memof the wet-mix pebucket I of Fig. l.

4 ber 50, however, I control it by means of a special cam rotatable with the gear'83.

.-As' indicated in Fig. 6, some member 30 connected to the aggregate valve vfor "movement therewith, which member maybe a valve-operating lever like the lever 30 but movable upwardly to open the aggregate valve and downwardly to closeiit, is disposed at one side of the casing 5| in association with a latch H5. When the aggregate valve is closed, the member 30 occupies theiull-lineposition shown in Fig. 6, and when the aggregate valve is open the member 30' occupies the dotted line. position. The latch member I I5; which is: shown as pivotally mounted on the side of the casing 5I, acts when in operative position to retain the member 30' in its lower position and thus to prevent opening of the aggregate valve.

:The latch. H5: is'controlled'by a suitable latchoperatingcammotatable with the worm gear 83. As is .cleaivfrom '7, this. cam is a composite structurejncluding a spider I I6 which supports a ring HI upon which three adjustable cam-segments H8, H9, and I are mounted. Conveniently, the ring H1 is: provided with a plurality of xarcuate slotsthrough which pass screws I2I holding the various cam-segments H8, H9, and

I20 inplace.

.Co-operating withthe cam-segments H8, H9, and I20 is a cam-roller. I23 mounted on a swinging arm I24 theiree end'of which is connected by a link I25 to the latch I I5 in such a way that whenever any ofthe cam-segments engages the roller I23 the latch H5 will occupy its operative position inwhich it prevents opening of the aggregate-valve. .The latch I I5 is biased to released position by any convenient means such,.for example, as a spring H5 which, to simplify illus- .tration,.is shown in the drawings as being located outsidethe casing'5l but which can be arranged in .any convenient'position or manner to perform itsintended function. As shown in the drawings, the cam1segments lI8,IIO, and I20 are so arranged asto' move. thelatch to operative position as soonastthe worm gear 83 begins to rotate, to hold the latch H5 in operative positionfor an interval, to release it for a second interval, and to return it to operative position thereafter.

Mounted on the swinging arm I24, I have shown a switch contact I35 which engages a stationary contact I36 when the latch H5 is in inoperative position, but which is moved outof engagement with thefixed contact I36 when the latch H5 is moved to operative position. -In.serieswith the contact I36 is a suitable signal, here shown as a lamp I31. The device. shown in Figs. 6, '7, and'8 also includes the signal lamp: I05 previously described,:but shows a somewhat different arrangement for the switch controlling that lamp. In this arrangement, the lamp I05 is connected in series with a stationary spring-contact I40 and a movable'spring contact I4I, the latter being mounted upon one arm of a bell crank I42 swingable about a vertical axis. The other end of the bell crankv I42 is pivotally connected to the swinging arm 63 which carries the stop 58, the arrangement being such that when the stop 58 is in advanced position the switch I40-I4I will be open.

In most respects, the device illustrated in Figs. 6, '7, and 8 operates similarly to that previously described. Normally, the parts occupy the positions respectively shown in Fig. 6. At the start of a mixing operation, a charge of'aggregate of proper weight is "placed in the aggregate weigh- This charge of aggregate is :quantity of aggregate.

H5 is retracted as just described, the switch sufficient extentv to operative position until after the cam 86 has engaged and retracted the latch 60 to permit the 'member50 to drop and release the dischargevalve 25, which is then operated to discharge the contents'of the mixer.

permitted to pass to the mixer by opening the aggregate valve I6, which opening movement involves movement of the member from the fullline to the dotted-line position of Fig. 6. When the initial charge of aggregate has been supplied to the mixer, the aggregate valve I6 is closed and the member 30 returned to its full-line position. The. member 50 is then raised to its intermediate position,-as inthe case of the device shown in Figs. I l to 5 inclusive. This movement of the member 50' looks the mixer-discharge device in closed positionand throws the worm into mesh with the worm-gear 83 to cause rotation of the worm gear 83 and the cams'rotatable with it. As is the case in the device shown in Figs. 1 to 5, movementof the control member 50 to its intermediate position does not unlock the bitumen valve.

immediately after the worm gear 83 begins to rotategthe cam-segment I20 engages the roller I23 and moves the latch I I5 to its operative position to prevent opening of the aggregate-valve. -As rotation of. the worm gear 83 continues and .while the latch H5 isstill held inoperative position by either or both-of the cam-segments H9 and I20, the cam member 65 engages the swinging arm 83 andretracts. the stop 58 to determine the termination of the dry-mix period. This movement of the arm 63 also closes the switch I-I4I and lights the lamp I05. The operator, being advised of the retraction of. the stop 58 by the lighting of the lamp. I05, raises the member to its extreme position, thus unlocking the bitumen valve and permitting the bitumen .in. the weighbucket I! to be added to the aggregate previously supplied to the mixer. After all bitumen in the weigh-bucket I1 is drained into the mixer, the bitumen-valve I8 is closed and the member 50 permitted-to drop to its intermediate position.

'.-As rotation of the cams continueand before the camengages the latch-60, the cam-segments H9 and I20 are carried out of engagement with the roller I23 to permit the latch- I5 to return to its inoperative position shown in Fig.6, under the influence of the spring H5. 'During the dry- ..mix period following the admission to the mixer of the original aggregate-supply, the aggregate weigh-bucket has been filled with the second When the latch member I35-I36 is closed to cause lighting of the signal lamp I3'I. During the interval in which the lamp I3! is lighted and the latch H5 retracted, the

operator opens the aggregate-valve to discharge the second. charge of aggregate into the mixer. I

following which the aggregate valve is again closed and the member 30' is restored to its fullline position.

At theconclusion of the interval provided for the addition of the-second charge of aggregate, the cam-segment I I8engages the roller I23, opens the switch I35-I36, and moves the latch H5 to The cam segment H8 has hold the latch member I I5 in operative position.

-The cam segment H9 is'adjustable circumferentially of the ring I I1 independently of the seg- -ment I20 to control the duration of the first drymix period-while the same segment H8 is also adjustable to provide any desired interval for -the-addition of thebitumen irrespective of the 2,147,575 a position of the cam-segment H9. If it is desired to use the device of Figs. 6, 7, and 8 to accomplish the same result as the device of Figs l to 5, the cam-segment H9 can be moved to close the gap between the segments H8 and I2!) and thus to hold the latch member I I5 continuously in operative position and to prevent any opening of the aggregate valve at any time after a timing cycle has once been started.

I claim as my invention:

1. In combination with a mixer, a binder-supply device and an aggregate-supply device therefor, a discharge device for said mixer, locks actuatable respectively to render said supply and discharge devices: inoperative, a movable member movable from a normal position through an intermediate position to an extreme position, means controlled .by said movable member and acting when said member is in any but its normal position to actuate the locks for said aggregate-supply and discharge devices, means controlled by said movable member and acting when said memher is in any'but its extreme position to actuate the lock for said binder-supply device, timing means,.and mechanism controlled by said timing means for preventing movement of said member from its intermediate position until after the expiration of a predetermined time following its movement into such intermediate position.

2. In combination with a mixer, a binder-supply device and an aggregate-supply device therefor, a discharge device for said mixer, locks actu atable respectively to render said supply and discharge devices inoperative, a movable member movable from a normal position through .an intermediate position to an extreme position, means controlled by said movable member and acting when said member is in any but its normal position to actuate the locks for said aggregate-supply and discharge devices, means controlled by said movable member and acting when said member is in any but its extreme position to actuate the lock for said binder-supply device, a retractable stop for preventing movement of said member from its intermediate to its extreme position, a second retractable stop for preventing movement of said member from its: intermediate position to its normal position, and timing means for successively retracting said stops.

3. In combination with a mixer, a charging device and a discharging device therefor, locks respectively associated with said devices, timing means operable at a predetermined time after actuation to release the lock for the discharging device, and a control member manually movable independently of said charging device to simultaneously operate the lock for the charging device and actuate said timing means, said charging device being operable to effect a charging operation without movingsaid control member. I

4. In combination with a mixer, a charging device therefor, a timing device, a control member for actuating said timing device independently of said charging device, a lock for said charging device operable upon actuation of said timing means, and connections controlled by said timing device for releasing said lock upon the expiration of a predetermined time following actuation of said timing means, said charging device being operable to effect a charging operation without moving said control member.

5. In combination with a mixer, a charging device therefor, a lock for said charging device, timing means operable upon a single actuation to lock said lock, to maintain it locked for a precharge devices inoperative,

termediate position to determined interval, to release it for a second andindependently predetermined interval, and

to again lock it, a signal device, and means operable during said second interval for operating said signal device.

6. In combination with a mixer, a binder-supply device and an aggregate-supply device therefor, a discharge device for said mixer, locks actuatable respectively to render said supply and discharge devices inoperative, a movable member movable from a normal position through an intermediate position to .an extreme position, means controlled by said movable member and acting when said member is in any but its normal position to actuate-the locks for said aggregate-supply and discharge devices, means controlled by said movable member and acting when said member is-in any but its extreme position to actuate thelock for said binder-supply device, a retractable stop for preventing movement of said member from its intermediate position to its extreme position, a releasable latch for preventing movement of saidmember from its intermediate position to its normal position, and timing means set in operation by movement of said member from its normal position to its intermediate position for temporarily retracting said stop and subsequently releasing said latch, said member being biased toward its normal position.

7. In combination with a mixer, a binder-supply device and an aggregate-supply device therefor, a discharge device for said mixer, locks actuatable respectively to render said supply and disa movable member movable from a normal position through an intermediate position toan extreme position, means controlled by said movable member and acting when said member is in any but its normal position to actuate the locks for said aggregate-supply and discharge devices, means controlled by said movable member and acting when said member is in any but its extreme position to actuate the lock for said binder-supply device, a retractable stop for preventing movement of said member from its intermediate position to its extreme position, a releasable latch for preventing movement of said member from its intermediate position. to its normal position, and timing means set in operation-by movement of said member from its normalposition to its intermediate position for temporarily retracting said stop and subsequently releasing said latch.

8. In combination with a mixer, a binder-supply device and anaggregate supply device therefor, a discharge device for said mixer, locks actu atable respectively to render said supply and discharge devices inoperative, a movable member movable 'from a normal position through an inan extreme position, means controlled by said movable member and acting when said member is in any but its normal position to actuate the locks for said aggregate-supply and discharge devices, means controlled by said movable member and acting when said member is in any but its extreme position to actuate the lock for said binder-supply device, a retractable stop for preventing movement of said member from its intermediate position to its extreme position, and timing means set in operation by movement of said member from its normal position to its intermediate position for temporarily retracting said stop, said member being biased toward its normal position.

9. In combination with a mixer, a binder-supply device and an aggregate-supply device there-- for, a discharge device for saidmixen-locks actuatable respectively to render said. supply and discharge devices ber movable from a normal position through an intermediate position tov an extreme position,

means controlled by said movable member and acting when said member is in any but its normal position to actuate the locks for said aggregate-supply and discharge; devices, means controlled. by said movable member and acting when saidmember is inany-but its extreme position to actuatethe-lock'ior said-binder-supply device, a retractable'stop for'preventing-movement of said member from its intermediate position to its extreme position, and timing means set in operation by movement ofsaid member from its normal positionto its intermediate position for temporarily retracting said stop,

10. In combination with a mixer, a bindersupply device and an aggregate-supply device therefor, a discharge device for'said mixer, locks actuatable respectively to render said supply and discharge devices inoperative, a movable member movable from a normal position through an intermediate position to an extreme position, means controlled -by-said movable member and acting when said-member is in any but its normal position to actuate-the locks for said aggregate-supply and discharge devices; means controlled-by said movable member and acting when said member is in any but its extreme position to actuate the lock for said binder-supply device, a retractable stop'for preventing move ment of said member from its intermediate position to its extreme position, a'releasable latch for preventing movement'of said member from its intermediate positionto its'normal position, and timing means for temporarily retractingsaid stop and subsequently releasing said latch, said member being biased toward its normal position.

11. In combination with amixer, a' bindersupply device and an aggregate-supply device therefor, a discharge device for said mixer; locks actuatable respectively to render; said supply and discharge devices inoperative, a movable member movable from a normal position through an intermediate position to anextreme position, means controlled by said movable member and acting when said member is in any but its normal position to actuate-the locks for said aggregate-supply and discharge devices, means controlled by said movable member and acting when said member is in-anybut its extreme position to actuate-thelock'for said binder-supply device, a retractable stop for preventing movement of said member "from its intermediate position to its extreme position, a releasable latch for preventing movement of'said member from its intermediate position toits normal position, and timing means for temporarily reinoperative, a movable mem-.

tracting said stop and subsequently releasing saidlatch.

12. In combination with a mixer, a binder-supply device and an aggregate-supply device therefor, a discharge device for said mixer, locks actuatable respectively to render said supply and discharge devices inoperative, a movable member movable from a normal position through an intermediate position to an extreme position, means controlled by said movable member and acting-when said member is in any but its normal position to actuate the locks for said aggre gate-supply and discharge devices, means controlled by said movable member and acting when said member is in any but its extreme position to actuate the lock for said binder-supply device, a retractable stop for preventing movement of said member from its intermediate position to its extreme position, and timing means for temporarily retracting said stop, said member being biased toward its normal position.

13. In combination with a mixer, a bindersupply device and an aggregate-supply device therefor, a discharge device for said mixer, locks actuatable respectively to render said supply and discharge devices inoperative, a movable member movable from a normal position through an intermediate position to an extreme position, means controlled by said movable member and acting when said member is in any but its normal position to actuate the locks for said aggregate-supply and discharge devices, means controlled by said movable member and acting when said member is in any but its extreme position toactuate the lock for said binder-supply device, a retractable stop for preventing movement of said member from its intermediate position to its extreme position, and timing means for temporarily retracting said stop.

14." In combination with a mixer, a charging device therefor, a lock operative to prevent operation of said charging device, and a timing means for controlling operation of said lock, said timing means including a rotatable member, a pair of circumferentially overlapping cam-segments mounted for relative circumferential adjustment on said rotatable member, a third cam segment mounted on said rotatable member and adjustable circumferentially toward and away from said pair of overlapping cam segments, and a cam follower operatively connected to said lock to render the lock operative when engaged by any of said cam-segments.

15. The invention as set forth in claim 5 with the addition of a discharge device for said mixer, a lock for said discharge device, and mechanism operable by said timing means for maintaining said discharge-device locked during such predetermined intervals.

LOUIS A. GUEDEL.

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