US2984461A - Mixing machines - Google Patents

Description

May 16, 1961 F. BUTLER HAL 2,984,461

MIXING MACHINES FiledJune 2o, 195s 2 sheets-sheet 1 Q l l, 1 l I i; I I I I I I I I I I I I I I I g m g u I 1 i .\\\\\\gx\\\\\\\\\\ ,f \l\ I 9 s g m, h i i m "a Q 4 :"lllllllllg E I I I s I I I I I I I I I i; si I I l l I N l f I In l IL ,m

INVENToRs FRANK BUTLER 1 HERBERT BOULTON ATTORNEYS May 16, 1961 F. BUTLER ETAL 2,984,461.

MIXING MACHINES INvENToRs FRANK BUTLER HERBERT 13;;LT0N

ATTORNEYS Unite rates Patent MIXING MACHINES Frank Butler, Knutsford, and Herbert Boulton, Culcheth,

near Warrington, England, assgnors to United Kingdom Atomic Energy Authority, London, England Filed June 20, 1958, Ser. No. 743,285

Claims priority, application Great Britain June 20, 1957 6 Claims. (Cl. 259-3) This invention relates to mixing machines.

Modern industrial manufacturing processes frequently involved several stages one of which is a mixing stage, and it is often desirable, from considerations of efficiency and economy, that the process should be a continuous one. The organization of a continuous process calls for careful integration of the several stages, and in this respect the mixing stage needs especial attention to ensure that each stage follows the preceding one smoothly and without undue delay.

It is an object of the invention to provide a multidrum mixing machine which delivers mixed material according to a specied time cycle.

A mixing machine according to the invention comprises a set of mixing drums mounted on and equally spaced round a drum carrying member, the drum carrying member being arranged to move the drums in a closed path from a charging point to a discharging point and then back to the charging point, means for rotating each drum about its axis, means for moving the drum carrying memberiin steps equal in size to the spacing between the drums, means for supporting the drums from the charging point to the region of the discharging point in an above horizontal position for mixing in the drums, and means for tipping the drums in turn as they enter the region of the discharging point to a below horizontal position for emptying of the drums.

The mixing machine of the invention has particular merit when it is used to mix materials in accurately weighed batches and to deliver the mixed materials to a pelleting press which is being operated to a specific pressing-time cycle.

By way of example, a mixing machine according to the invention will now be described with reference to the accompanying drawings wherein:

Fig. 1 is a sectional elevation on two planes 60 apart at the centre line;

Fig. 2 is a plan view of a ratchet mechanism, and

Fig. 3 is a plan view of part of a cam track.

Referring to Fig. l, a casing 1 comprising a main frame 2 and a removable hood 3 has located within it six mixing drums (two only of which are shown in the drawings and designated 4) mounted on a support plate 5, the drums 4 being equi-spaced at 60 intervals around the plate 5. A friction wheel 6, driven (via a vertically arranged hollow driving shaft 7 and bevel gears 8, 9) by a motor 10, provides rotation of the mixing drums 4, each drum having a driving shaft 11 keyed to a friction roller 12 normally in Contact with the wheel 6. The support plate is periodically rotated in 60 steps (via a vertically arranged driving shaft 13 and an associated piston-operated ratchet mechanism 14) so that each drum 4 in turn is accurately positioned beneath a charging funnel 15 in the hood 3. Each driving shaft 11 of the drums 4 has a bearing casing 16 surrounding it and attached to each casing 16 is a spring loaded arm 1T having a guide wheel 18 resting on an inclined cam track 19. As the plate 5 is rotated through 60 the guide Wheels 18 follow the cam track 19 which is shaped so that as one of the drums 4 is positioned beneath the funnel 15, the following drum 4 is tilted. as shown to discharge into a discharge hopper 20. The funnel 15 is shown in the position indicated (180 displaced from the hopper 20) for convenience and clarity, its true position being 60 in advance of the discharge hopper 20 as seen in a plan view, the term advance being used having due regard to the direction of rotation of the plate 5.

In greater detail, the main frame 2 is of rectangular section and has a base plate 21, a transverse support member 22 and a top annular plate 23 -having a flange 24 to which the hood 3 is tted. The hopper 20 is secured to the frame 2 and the plate 23.

Each drum 4 has an open end through which material to be mixed is charged into the drum and through which the material after mixing is discharged, and comprises a tapered eight-sided body 25 having an integral base plate 26 secured by bolts 27 to an annular plate 2S which is welded to a ring 29 integral with the shaft 11. The shaft 11 is supported in the casing 16 by two bearings 30 and the roller 12 is located on the shaft 11 by a key 31 and is secured to a threaded stud 11a on the shaft 11 by a washer 32 and bolt 33. Each drum 4 is pivotably mounted on a pin 34 carried in two trunnioris 35 mounted on the plate 5. The plate 5 has six equi-spaced slots 36 through which the shafts 1.1 extend to enable the rollers 12 to contact the wheel 6. Six tapered radial webs 37 equi-spaced between the slots 36 are welded to the plate 5 and to a central collar 3S which is also welded to the plate 5. The collar 38 is located on the shaft 13 by a key 39 and secured t'o the top of the shaft 13 by a washer 40 held by nuts 41 locking on a threaded stud 42.

An annular plate 43 secured to the plate 23 by bolts 44 supports a drive housing 45, welded support webs 46 being provided. The housing 45 has welded end rings 47 and carries two outer bearings 48 which support the shaft 'l'. Recesses in the ends of the shaft 7 carry two inner bearings 49 which support the shaft 13.

The friction wheel 6 is secured to a flange 50 on the shaft 7 by bolts 51. The bevel gear 8 is secured to the shaft 7 by a key 52 and a split ring 53, screws 53a being provided. The bevel gear 8 meshes with the bevel gear 9 which is located on a shaft 54 by a key 55, the shaft 54 being driven by the motor 10 through a gear box 56. A sealing ring 54a is provided where the shaft 54 passes through the member 22. The housing 45 is provided with end caps 57 and sealing rings 58.

The ratchet mechanism 14 has a primary ratchet wheel 59 and a secondary ratchet wheel 60 both located on the shaft 13 by a common key 61 and supported on the shaft 13 by a washer 62 held by nuts 63 locking on a threaded stud 64. An operating arm 65 has a collar 66 carried on a bearing 67 surrounding a flange 68 on the primary ratchet wheel 59. The ratchet wheel 59 also has a flange 69 locating the lower end of the shaft 7. The ratchet mechanism 14 has an associated pawl 70 mounted on a pawl support 71 and held by a screw 72.

Fig. 2 shows the ratchet mechanism 14 in more detail. A pawl 73 is mounted on the operating arm |65 and pivotably held by a screw 74, and a connecting link 76 (also shown in Fig. 1) is secured to the arm 65 by a pin 77. The link 76 has a piston rod 78 actuated from an air cylinder 79 (Fig. l). The pawl support 71 carries the pawl 70 and a pawl 80 held by a screw 81, the pawls 70, 80 being pivotable about the screws 72, 81. The arm 65 also carried a trip latch 82 pivotably mounted on a pin 75. The ratchet wheel 59 has six equi-spaced ratchet teeth 83 formed by radial edges 84a and inclined edges 84b and the ratchet wheel 60 has six equi-spaced ratchet teeth 85 formed in the opposite direction by radial edges 86a and 3 inclined edges 86h. The shaft 13, the key 61 and the ange `69 on the wheel 59 lare also shown in Fig. 2.

Fig. 3 shows the shape of the inclined cam track 19. The track 19, other than that shown in the ligure, is circular (as shown in part at Y87) but, as shown in the figure, it dips sharply downwards and inwards at 88 reaching its lowest and most inward point at 89 before gradually rising outwards at 90 to regain its circular shape. The angle 91 between lines 92 and 93 is 60.

Thus as the wheel 18 of one of the drums 4 follows the track 19 at 88, the drum 4 is tilted to discharge when the wheel 18 reaches the point '89 and then as the wheel 118 follows the track 19 at 90, the drum is gradually raised to its normal position.

Referring again to Fig. 1, the cam track 19 is shown generally supported on asupport ring 94 but is supported directly from the main frame 2 at its lowest and most inward point. Also shown in Fig. 1 is anozzle 95 (for introducing a wetting agent into the drums 4) mounted in the hood 3 adjacent to the funnel 15. The hood 3 is provided with observation windows 96 and the motor 10 is provided with an air line 97 for purging purposes.

The operation of the mixing machine will now be described having particular reference to the operation of the ratchet mechanism 14 (Fig. 2). When the piston rod 78 is actuated in a forward direction as shown by arrow 918, the arm 65 is rotated in the direction shown by arrow 99. The pawl 73 comes into engagement with one of the edges 84a on the wheel 59 as shown, the trip latch 82 momentarily lifts the pawl 80 (as shown) from engagement with one of the edges 86a of the tooth 85 on the wheel 60 to free the wheel 60 and then rides over the surface of the pawl 80. The pawl 73 thus rotates the wheels 59, 60, the pawls 70, 80 riding over the surfaces of the wheels 59, 60 until the position is reached where the pawl S rides over the inclined edge 361) of the next ratchet tooth 85- of the heel 60 and comes into contact with the radial edge 86a 0f that tooth, thus preventing further rotation of the wheels 59, 6i). As this occurs, the piston rod 78 reaches the end of its forward stroke and the pawl 70 drops into the corresponding tooth 83 in the wheel 59 and comes into contact with the radial edge 84a of that tooth and thus prevents the wheels 59, 60 from slipping back. When the piston rod 78 is actuated in the backward direction as shown by arrow 100, the arm 65 is rotated in the direction of arrow 101 and the pawl 73 rides over the surface of the wheel 59 to drop into the next tooth 83 in readiness for the next forward stroke of the piston 78. The equi-spacing of the teeth 83, 85 on the Wheels 59, 60 and the pawls 70, 80 ensures accurate 60 rotation of the plate 5. The air cylinder 79 is periodically pulsed with compressed air to actuate the forward strokes Aof the piston rod 78 and periodically evacuated to actuate the reverse strokes of the rod 78. The pulses and evacuations may be timed to give any convenient total mixing time (i.e. from charging of one of the drums 4 to discharging of that drum).

The drums 4 are twelve inches deep, ten inches across the corners at their base, six inches across the corners at their top, and are normally inclined at 30 to the horizontal.

We claim:

1. A mixing machine comprising a set of mixing drums pivotably mounted on and equally spaced around a drum carrying member, each of said drums having an open end for charging and discharging thereof, the drum carrying member being arranged to move the drums in a closed path from a charging point to a discharging point and then back to the charging point, means for rotating each drum about its axis, means for moving Ythe drum carrying member in steps equal in size to the spacing between the drums, said drums having support arms movable over a track, the track being shaped so that the drums are supported in an above horizontal 'position for mixing in the drums except in the region of the discharging point where the track shape provides that the drums are tipped to a below horizontal position for emptying of the drums. l

2. A mixing machine as claimed in claim 1 wherein said mixing drums are trunnion mounted on the drum carrying member.

3. A mixing machine as claimed in claim 2 wherein rotation of each drum about its axis is provided for by engagement of a wheel on a spindle of each drum with a common driving wheel except in the region of the discharging point.

4. A mixing machine as claimed in claim 3 wherein th common driving wheel is driven continuously by a driving motor and the drum carrying member is moved in steps by a piston operated ratchet mechanism.

5. A mixing machine as claimed in claim 4 wherein the mixing machine is enclosed in a casing having a hopper and a discharge chute, the hopper coinciding with the charging point and the discharge chute coinciding with the discharging point.

6. A mixing machine as claimed in claim 5 wherein a nozzle for introducing a wetting agent into the drums is provided adjacent to the hopper.

References Cited in the tile of this patent UNITED STATES PATENTS 2,482,324 Dachkevitch Sept. 20, 1949

Images