US2400765A - Mechanism for actuating clutches and the like - Google Patents

Description

Why 21,- 1946. I A. McMlLLAN MECHANISM FOR ACTUAT ING CLUTCHES AND THE LIKE Filed Dec. 20, 1943 grvvq/rvtqb ANDREW McMILLAN,

Patented May 21, 1946 MECHANISM FOR ACTUATING CLUTCHES AND THE LIKE Andrew McMillan, Milwaukee, Wis., assignor to Chain Belt Company, Milwaukee, Wis., a corporation of Wisconsin Application December 20, 1943, Serial No. 515,015

3 Claims.

The invention relates to mechanism for actuating clutches and the like, and while it may find other applications, for purposes of disclosure it has been illustrated and will be described in the environment for which it has been primarily designed, viz., control of the skip clutch of a concrete mixing machine.

It is customary in such machines toelevate and lower the skip (by means of which batches of concrete making materials are charged into the mixing drum) by means of hoisting mechanism including cables and winding drums therefor, which drums are driven through appropriate mechanism from the mixer motor. Usually such motor drives a continuously rotating countershaft from which power may be taken at will through friction clutches to rotate the mixing drum and to drive various other instrumentalities of the machine, including the skip cable winding drum,

One of the objects of the present invention is to provide mechanism which, while under the manual control of the operator, will effect actual shifting of a clutch, such as that for the skip cable winding drum, by power supplied by the motor.

One form of the apparatus is disclosed in the accompanying drawing forming a part of this specification, in which like referencecharacters designate like parts in allthe views, and in which:

comprises a framework Ill, mounted for ground traverse upon crawler treads H, and having a mixing drum l2 mounted within it for rotation upon rollers [3. A motor I4 is mounted upon the said framework I and, when operating, continuously rotates a countershaft I5 through a speed reducing drive, not shown. A skip [6, for charging materials into the drum I2, is pivotally mounted on the frame Ill at I I and is adapted to be elevated to and lowered from drum-charging position by cables l8 passing over sheaves I9 and 'wound upon drums carried by a transverse shaft 2!. This shaft is-adapted tobe rotated by a bull wheel 22 upon which is wound a cable 23,.

which passes to and is also wound upona winding drum 24, here shown as loosely mounted upon the countershaft l5 and adapted to be clutched thereto by a friction clutch 25 having a shifting Figure 1 is a more or less diagrammatic side elevational view of a portion of the elements of proximately on the plane indicated by the line 4-4 of Fig. 2, looking in the direction of the arrows; and

Fig. 5 is an enlarged sectional-elevational view, approximately on the plane indicated by the line 55 of Fig. 1, illustrating the manual control lever for the shifting mechanism, and its mounting and connections.

The concrete mixing machine shown in Fig. 1

collar 26 associated therewith.

The parts thus far referred to are all conventional in this type of machine, and are here more or less diagrammatically shown.

The mechanism for shifting the clutch 25 to couple the drum 24 to the shaft l5, whereby the skip l6 may be raised, comprises a supporting member or bracket 30, which may be suitably mounted on the'machine frame In in juxtaposition to the. said shaft, asillustrated in Fig. 1. The bracket member 30 includes a pair ofspaced upstanding plates 3| and 32 which mount a horizontal rod 33 which serves as a support and guide for a block 34 whichis slidably mounted thereon. This block is provided with a pair of trunnions 35 which constitute the fulcrum of anupwardly extending lever 36, which is connected at 31 to a link 38 which in turn is connected at 39 to a shifting yoke 49, pivoted as at 4| and engaging pins 42 carried by the clutch-shifting collar 26. A cam 43 is rigidlymounted on the shaft I5 adjacent the winding drum 24,. and the lever 36 carries a follower roller 44 positioned for co-operation with the cam, as will appear more fully below.

The trunnions 35 of the block 34 also pivotally receive one end of a pair of links 45, the other ends of which are pivotally connected as at 46 to an arm 4'! of a bell-crank lever 48, pivoted as at 49 between a pair of longitudinal ears 59 which may extend from the transverse plate 32.

The other arm 5! of the bell-crank lever 48 has.

one end of a wire or cable 52 connected to it at 53, which wire or cable extends through a housing or sheath 54 upwardly to the operators station, adjacent the forward end of the mixing drum [2. The frame frequently includes a protective panel 55 for shielding the drum and the wire or cable 52 may extend up behind this panel to a control box or housing 56 formed in or carried by the panel. In this housing a control lever 51 is mounted on a shaft 58 which also carries an arm 59 to which the upper end of the wire or cable 52 is connected as at 60.

The bracket is provided with a stop member 6| so disposed as to be engaged by the arm 41 as it reaches the position shown in Fig. '3. In this position the pivot 46 has passed slightly below the dead-center line between pivots and 49, and the said engagement between the arm 4'! and stop 6| therefore serves to lock the block 34 in the Fig. 3 position whereby its trunnions 35 may serve as a fixed fulcrum for the lever 36. The roller 44 carried by the said lever may thus be retained in operative relation to the cam 43 withoutthe necessity of the operator holding the control lever 51 in the broken line position of Fig. 5.

As above indicated, the normal position of the ,parts is that illustrated inFigs. 1 and 2. When it is desired to raise the skip IS, the operator merelymoves the control lever 5'! from the full line to the broken line position of Fig. 5 which, through arm 59, cable 52, bell-crank lever 48 and links 45, draws the block 34 along the guide rod 33 to the position illustrated in Fig. 3. During this movement the lever 36 pivot on the link connection 3'! to assume the position illustrated in full lines in Fig. 3, and its roller 44 is moved ing of the clutch is performed mechanically by power derived from the motor 14, and since under present day paving practice it may be necessary to elevate the skip every to '70 seconds, and since this is only a portion of the operators duties, the present mechanism provides appreciable relief for him.

While one form of the invention has been illustrated and described, it will be obvious that those skilled in the art may vary the details of construction as well as the precise arrangement a bracket structure having a guide; a block slidinto operative relation to the cam 43. The shaft I5 and cam 43 are continuously rotating at a relatively low speed, say to R. P. M., and as the high portion of the cam engages the roller, the latter together with the lever 36 will be forced .to the broken line position of Fig. 3, which move ment through link 38 and shifting yoke 40 will shift the clutch 25 to engaged position and couple the winding drum 24' to the shaft l5. The cable 23 will thus be wound upon the said drum,

and unwound from the bull wheel 22, rotating the latter and with it the winding drums 20, winding the cables l8 thereon and elevating the skip. As is well known to those skilled in this art, mixing machines of this type are ordinarily provided with an automatic clutch knock-out (not here shown) actuated by the skip as itreaches its discharge station, and as therclutch is of a type which will remain engaged until such knock-out occurs, the operator may return the control lever 51 to its normal full line positionas soon as the skip starts up. Such return will restore the block 34 to its Fig. 2 position, the lever 36-pivoting about the link connection 31 (in its broken line position of Fig. 3) and moving roller 44 out of operative relation to the cam 43. When the automatic clutch knock-out occurs, the parts will be fully restored to the Fig.2 position, with roller 44 still out of operative relation to the cam.

Whilethe control is manual, the actual shiftably mounted on said guide, providing a shiftable fulcrum for said lever; a bell crank mounted on said bracket structure and connected to said block; and a manually operable control member connected to said bell crank for causing the latter to slide the block on the guide and move the lever and follower into operative relation to the cam whereby it may swing the lever on the fulcrum and actuate the clutch shifting element.

2. In mechanism'for actuating a clutch shifting element; a power-driven cam; a lever connected to said shifting element and provided with a follower for engagement with said cam; a bracket structure having a guide; a block slidably mounted on said guide, providing a shiftable fulcrum for said lever; a bell crank mounted on said bracket structure; links connecting said block to one arm of said bell crank; a manually operable remotely located control member; and a cable connection between said control member and the other arm of said bell crank, whereby the latter may be caused to slide the fulcrum block and move the lever and follower into operative relation to the cam, where the latter may swing the lever on the fulcrum and actuate the clutch shifting element.

3. In mechanism for actuating a clutch shifting element, a power driven cam; a lever connected to said shifting element; a supporting member; means slidably mounted on said member providing a bodily shiftable fulcrum for said lever; a bell crank connected to said fulcrum means for shifting the latter uponsaid support ing member to move the lever into position to be engaged by the cam, whereby the latter may swing the lever upon the fulcrum and actuate the shifting element, a portion of the bell crank being engageable with the supporting member to provide a toggle lock for temporarily retaining the fulcrum in said shifted position; and manually operable means for actuating said bell crank.

' ANDREW McMILLAN.

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