US1963953A - Concrete mixer - Google Patents

Description

June 26, 1934. J. E. BUSHNELL 1,963,953

CONCRETE MIXER Filed June 5, 1930 4 Sheets-Sheet l June 26, 1934. E, BUSHNELL CONCRETE MIXER Filed June 5, 1930 4 Sheets-Sheet 2 June 26, 1934.

J. E. BUSHNELL 1,963,953

CONCRETE MIXER Filed June 5, 19 30 4 Sheets-Sheet 3 Evwwboz June 26, 1934.

J. E. BUSHNELL CONCRETE MIXER Filed June 5, 1930 4 Sheets-Sheet 4 aumwwoz Z Patented June 2%, 1934 CON-CEETE MIXER Bushnell, North Plainfield, N. J., as-

signer to Ztansorne encrete Machinery Com-- pany, Plainfield, N. 5., a corporation of New Jersey Application June 5, 1936, Serial No. 459,294

6 Claims.

The present improvements relate in general to concrete mixing apparatus and more particularly to an improved control mechanism in combination therewith.

A primary object, among others, of the present improvements, is to provide an improved mixing apparatus having means for automatically accomplishing a predetermined cycle of operations. A further object is to provide a device of the aforementioned type wherein the operation is incepted by actuating a single control member.

Another object is to provide a novel control mechanism for the charging and discharging members of concrete mixers which compels a selected sequence of operations. Automatic means for arresting the operations at predetermined intervals constitutes a further object of the improvements.

In an automatic mechanism of this character, it is desirable that the steps in the operation follow a prescribed sequence, and it is therefore.

an object of the improvements to provide safety means for accomplishing this result, which also functions to prevent a recurrence of steps in the cycle.

These safety means likewise constitute disabling means for certain elements of the control mechanism.

A further object of the improvements is to provide a novel arrangement of power distribution in conjunction with a novel mechanical control means therefor, in apparatus of the chosen type.

To improve and simplify the functioning of trol mechanism;

Fig. 4 is an end elevation of the device of Fig. 2, looking in the direction of the arrow.

Referring to the drawings, the apparatus includes the usual frame members 10 on which the rotary drum 11 is suitably mounted. A power unit 12 is associated with said drum and operatively connected therewith for imparting rotary motion thereto.

Means for charging the drum 11 with dry aggregates through drum inlet 13 is provided in the form of a loading skip 14 pivotally mounted on shaft 15. As is common, said skip receives the charge of aggregates when in lower position (Fig. 2) and is adapted to be elevated by said power means 12 through cables 16, 16 and drums 1? to discharging position where the aggregates pass therefrom through inlet 13 to drum 11.

A tank 18 having conduit 19 extending through inlet 13 into the drum is provided for supplying the aggregates with a predetermined quantity of water. Mixing blades (not shown) are provided in the interior of the drum which is adapted to rotate, and mix the batch for a predetermined interval as determined by batch meter 20. A pivotally mounted discharge chute 21 is adapted to be swung into discharge opening 22 for discharging the contents of the drum whence the freshly mixed concrete may be distributed in chutes, bar rows or the like. As illustrated, said chute may be swung to the dotted line position whereit is ineffective.

As is well known, the entire device, including the present improvements, may be provided with suitable traction means. While the improvements have been illustrated in connection with pivoted charging and discharging members, it is obvious that a batch hopper and rotating discharge elbow of the type illustrated in'my copending applications, Number 459,293, filed June 5, 1930, and Number 609,876, filed May 7,1932, may likewise be employed.

A clearer understanding of the organization and details thereof may be had upon reference to Fig. 1, wherein the ring gear 25, surrounding drum 11, is in mesh with gear 26 of the transmission of power unit 12. 7 Power transmission means for elevating the loading skip 14 includes the shaft 27 having gear 28 in mesh with gear 26. A hoist drum 29, is associated with said shaft 27, and has hoist cable 16* attached thereto. In' order to apply power from shaft 27 drum 29 at selected intervals, a clutch 30 is provided which is operable through shaft 31 by clutch lever 32. Brake lever 33 and shaft 34 are provided for lowering the skip 14 under manual control, as is common.

Pivot shaft 15 of skip 14 is provided with a bell-crank lever 35, the construction being such that all these elements move simultaneously. A lever 36, keyed to clutch shaft 31, is, connected to lever 35 at 35 by a cable 37 having sufficient slack whereby when skip it is in elevated or dis charging position said cable is drawn taut and exerts a pull on lever 36 thereby releasing clutch 30. As aforementioned the brake is employed in lowering the skip.

Referring now to the discharge end of the mixer 11, the chute 21 is keyed to shaft 38 which has a lever 39 fixed thereto. The bifurcated end of said lever is pivotally connected to connecting rod 40, said rod having one end extending beyond lever 39 and the other end connected to crank 41. The crank shaft 42, to which crank 41 is keyed at one end, has a bevel gear 43 keyed to the other end thereof. Interposing these members, a dog 44 is also keyed to said shaft. The relation of these parts to shaft 42 is apparent from Fig. 4, the showing of the dog 44 on Fig. 1, being slightly displaced for convenience in illustration.

Means for rotating bevel gear 43 and rocking chute 21 comprises gears 45, 46 and clutch 47. As illustrated, gear 45 is always in mesh with ring gear of mixer 11, while bevel gear 46 is in mesh with bevel gear 43, the clutch 47 being positioned between said gears for connecting or disconnecting the power at will.

Clutch 47 is arranged to be operated manually by bellcrank lever 48 pivoted at 49, the shorter leg of said lever being operatively connected with slide bar 50. Said bar is pivotally connected at 51 to one end of another bell crank 52, pivoted at 53, the other end of said lever being connected at 54 to clutch 47. Upon exerting an upward pull on lever 48, the lever 52 is rocked in a clockwise direction, whereby clutch 47 is thrown in and power from gear 25 is imparted to gear 43. When lever 48 is released, spring 55 urges lever 52 in a counterclockwise direction for releasing said clutch. 7

The rear face of gear 43 is provided with an annular cam member 56 which protrudes from the face thereof. Two notches 57 and 58 are provided in said cam, being located approximately 180 apart. As illustrated, the aforementioned slide bar 50 has a portion extending toward and contacting said cam surface 56. This bar is held against the cam by spring 55, but as the bevel gear 43 rotates, the bar 50 enters one or the other of notches 57' and 58. When the bar is in one of these notches, the clutch 47 is released, but when riding on the cam surface, the clutch is held engaged. It is apparent therefore that in the full 1 line position of lever 48 (Fig. 1) gear 43 is locked against rotation and clutch 47 is disengaged. An upward pull on said lever, closes the clutch and unlocks said gear.

In order that the clutch lever 32, for operating 5 the power transmission of skip 14, may be acconnected to link 62 at 63.

tuated under the influence of a single control lever 48, the present improvements provide a lever 60, pivoted at 61, with one end in alignment with revolving dog 44 and the other end pivotally Said link extends towards and terminates adjacent lever 32, where the link has a slotted portion 64 which normal- 1y fits over lug 65 which is fixed to clutch shaft 31. As illustrated an anti-friction roller 66 forms '5 one end of slot 64 and engaged lug 65.

I a cable '71 has one end attached to lever at '72,

and extends over sheaves 73, 74, 75 and 76 and terminates at '77 on connecting rod 40. It is notable that sheave 75 is positioned on control lever U 48. A further cable 78 connects the batch meter 20 to cable 71. r

The foregoing elements perform a predetermined cycle of operations as follows: Assuming that the drum 11 is rotating and mixing a batch of ingredients, chute 21, crank 41 and dog 44 are in dotted line positions. To discharge the contents of the drum, lever 48 is manually raised, thereby removing lock bar from the notch in cam 56, at the same time clutch 4'7 is engaged, thereby rotating bevel gear 48 and with it shaft 42 and crank 41. This movement causes chute 21 to swing into drum 11 (full line position Fig. 1). When the chute has thus been swung to discharging position, the gear 43 has traveled approximately 180, so that spring urges bar 50 into notch 58, thereby automatically releasing clutch 47 and locking gear 43. During this 180 travel, the control lever 48 is held up and the clutch held in engagement by reason of the fact that bar 50 is riding on the cam surface 56.

As aforementioned, dog 44 rotates with shaft 42 and is so positioned thereon, that it engages lever a slight interval before the clutch 21 and gear 43 reach the end of their travel. This engagement urges lever 60 and link 62 to the right (dotted line position, Fig. 1) so that when the elements reach the end of the aforementioned 180 travel, dog 44 has actuated link 62 to dotted line position.

In moving to the right (Fig. 1), the link 62 pulls lug in a clockwise direction, thereby throwing clutch 80 into engagement and causing skip 14 to be elevated to discharging position, whence the dry aggregates enter drum 11 to be mixed therein. It will be remembered that the chute 21, during the foregoing interval, is in full line position (Fig. 1) for discharging the previous batch from drum 11. Since a new batch is now entering the drum, the discharge chute must be rendered inefiective during the mixing interval as determined by the batch meter 20. This function is accomplished automatically by means of cable 71.

As skip 14 is elevated, the shaft 15 and lever 35 rotate in a clockwise direction, thereby exerting a pull on cable 71 which is fixed at '77 to rod 40. Accordingly, the only element experiencing that pull, which is incapable of resisting it, is the sheave '75 and lever 48. These members are accordingly raised (overcoming the energy of spring 55) so that bar 50 is withdrawn 7 from notch 58 in the cam surface 56 and clutch 47 is engaged, thereby causing bevel gear 43 .to execute another 180 turn, during which the chute 21 is withdrawn to ineffective (dotted line) position. I

It is apparent that as crank 41 partakes in this'second 180 cycle, the cable 71 is slacked. so that handle 48 is free to drop and bar 50 enters the succeeding notch, thereby disengaging clutch 47 and locking chute 21 in dotted line position (Fig. 1). Accordingly, all of the" operations described in the cycle are accomplished automatically by a single control member 48 which needs to be manually raised but once, to

incept the sequence of steps. I

When employing power operated mechanical means it is necessary to provide certain safe-' guards against contingencies which would permit destructive operation of the mechanism or mixing up of the cycle of operations. To this end the cables 37, and 68 are provided. When the skip 14 is raised the cable 3'7. through lever 35, pulls upon lever 36, thus disengaging the clutch 30. In order that this movement may be accomplished without interference from the cooperating ing 65 and link 62, the latter is freed which lifts the link up to dotted line position (Fig. l) where it is clear of lug 65. It is apparent from this construction that lever 32 may be manually used to engage clutch 30 at any time independent of the interlocking control, but the cable 3'7 prevents such actuation of lever 32 so long as skip 14 is raised, thereby preventing overdraft of the skip. After dog 44 has passed from contact with lever 60, link 62 returns to its full line position (Fig. 1).

A further safeguard is to so arrange the cable 71 that when the skip 14 is raised it will func tion to swing the chute 21'out of the drum 11, if it is in discharge position therein, but will not swing said chute into the drum, if for any reason it is found out of the drum at the time the cable 71 is called upon to function. This is accomplished by attaching the cable end to rod 40 at 7'7, so that when the chute 21 is swung out, the rod 40 is at the upward limit of its travel thereby causing a slack in cable '71 so that if skip 14 is raised and lever 35 pulls thereon, it will merely take up part of the slack without affecting lever 43 or causing clutch i? to be engaged.

Accordingly a single pull on actuating lever 48 discharges the contents of drum 1'7, swings chute 21 to ineffective position and charges the drum with another batch. If desired the charging and discharging of water tank 18 may be operatively connected with the mechanism described for operation therewith. Upon reference to my copending application filed February 23, 1928, Serial No. 256,208, a control mechanism adapted to be employed with the present improvements is disclosed.

The advantages of this simplified construction will be apparent to those skilled in the art. The present improvements as coordinated and synchronized promote a more thorough and efficient operation of the organization and insure against premature or accidental discharge from the drum 11. Furthermore, the cooperating elements of the control mechanism together with the safeguards provided, afford a unitary interlocked control of novel and durable character.

Various modifications and rearrangement of parts within the scope of the present improvements will be apparent to those familiar with the art.

I claim:

1. In a concrete mixing apparatus having a rotary drum, power means and charging and discharging members adapted to operate in a predetermined sequence, an interlocking control mechanism comprising a lever and crank actuating means for said discharging member including a normally released clutch, manual actuating means for said charging member including a normally released clutch, a releasable member connecting said means, a manual operating member for said first named clutch including a cam and lock therefor after a predetermined operative interval, a cam fixed to said skip, a cable having one end fixed to said cam, a rotatable member mounted on said manual means, said cable being looped around said rotatable member and having its free end operatively connected with said chute, said cable being responsive to movement of said charging member after said clutches are thrown in for disabling said connecting member, and releasing said lock and concurrently throwing in its associated clutch, said last named means being constructed and arranged for preventing subsequent interference With said lock by skip movements.

2. A mixing apparatus comprising a mixing drum, a charging skip and a discharge chute, a crank means for swinging said chute in two directions, a clutch for operating said crank, gear means intermediate said clutch and crank, a notched cam on said gear means, a manually operated member for moving said clutch and engaging and disengaging said notched cam, a second clutch for actuating said skip, a releasable arm responsive to movements of said crank means for engaging said clutch, and cable means having one end attached to said crank and the other end to said skip, said cable being looped around said manually operated member whereby elevation of said skip actuates said member when said chute is in discharging position.

3. A mixing apparatus comprising a mixing drum, a charging skip and a pivoted discharging chute, crank means for actuating said chute in two directions, gear means attached to said crank, a clutch for intermittently actuating said gear means, a notched cam on said gear means, a cam member fixed to said crank adjacent said gear means, a manually operated member for moving said clutch and engaging and disengaging with said notched cam, a second cliitch for actuating said skip, a releasable arm responsive to movements of said last named cam for engaging said last named clutch, a cam member attached to said skip, cable means having one end fixed to said last named cam, a freely rotatable member fixed to said manually operated member, said cable passing therethrough and having its free end fixed to said crank adjacent said chute, said cable means operable by a predetermined movement of said skip for automatically disengaging said manual member and actuating said first named clutch for swinging said chute t0 non-discharging position, said cable means being ineffectual for operating said manual member when said chute is in non-discharging position regardless of movement of said skip, manualiy operated means attached to said second clutch for manual operation of said skip independent of the cable means and first named clutch.

4. A mixing apparatus comprising a mixing drum, a charging skip and a pivoted discharging chute, power means, a clutch engageable with said power means, a crank and lever device operatively connected to said clutch and chute swinging said chute in two directions, manual means including a lever for engaging said clutch for swinging said chute in one direction, mechanism including a cable for elevating said skip in response to movement of said chute, automatic means including a cable operatively connected with said skip, chute and manual means, said cable being held taut in one position of said chute whereby elevation of said skip operates said manual means for again actuating said clutch for swinging said chute to another position, said last named cable being slack when said chute is in said last named position whereby said means and cables thereafter are ineffective for actuating said clutch until the latter has first been manually operated to tighten said last named cable.

5. A mixing apparatus comprising a mixing drum, a charging skip and a pivoted discharge chute, power means, a clutch engageable with said power means, a crank and lever device operatively connected to said clutch and chute swing- .ing said chute to discharging and non-discharging positions, manual means including a lever for engaging said clutch for swinging said chute to discharging position, releasable mechanism for elevating said skip in response to the aforementioned movement of said chute, said mechanism including a clutch and cables, cable means responsive to movements of said skip, operatively connected with said lever and chute, said cable being held taut by said chute whereby elevation of said skip again actuates said first named clutch for swinging said chute to non-discharging position, said cable means being slack when the chute is in non-discharging position whereby said cable means is ineffective for actuating said clutch when said chute is in non-discharging position.

6. A mixing apparatus comprising a mixing drum, a charging skip and a pivoted discharging chute, power means, a clutch engageable with said power means, a crank and lever device operatively connected to said clutch and chute swinging said chute to discharging and non-discharging positions, mechanism including a notched cam for chute to discharging position, mechanism in-;

cluding a cable for elevating said skip in response to the aforementioned movement of said chute, a cam member attached to said skip, a cable having one end fixed to said last named cam, a rotatable member fixed to said lever, said cable passing intermediately around said rotatable member, said cable having the other end thereof operatively connected to said chute, said cable operable by elevation of said skip for again unlocking said first named mechanism and. for actuating said clutch for swinging said chute to non-discharging position, said cable being held taut by said skip only when in charging position, said cable being inefiective for actuating said clutch and for disturbing said locking mechanism when said chute is in non-discharging position.

JAMES E. BUSHNELL.

Images