US2246846A - Mulling mill - Google Patents

Description

June24, 1941. 'D N S Y 2,246,846

MULLING MILL' Filed Jan. 31, 1940 5 ShfiBW-Shet 1 v INVENTOR 124/1054, E flE/wzwy Jun; 24, 1941. D. E. HENNESSY MULLING MILL Filed Jan. 31, 1940 3 Sheets-Sheet 3 Patented June 24, 1941 STATES PATENT OFFICE MULLING IVHLL Daniel E. Hennessy, Leominster, Mass. Application January 31, 1940, Serial No. 316,550

4 Claims. (CI. 83-45) This invention relates to mulling mills intended particularly for mulling pigment for paints. It has for its object a product of a mill of this general character which will be very simple of construction, easily taken apart for cleaning, and producing a mulled product of great uniformity and of any required degree of fineness. The mill operates upon the principle that if an annular muller or cup be pressed against the face of a large rotating mulling disk and held against bodily travel therewith the annular muller will be set into independent rotation. While prior devices embodying this broad principle have been proposed they have not been satisfactory in practice on account of their inability to control the grinding process. It is therefore the object of the invention to improve prior mechanisms to an extent which will permit their use in obtaining high quality grinds under production conditions. A further object is to provide a mulling mill in which the annular and disk members will automatically form their mating surfaces into optically fiat condition. A further object is to improve the feeding and mixing of the material prior to the mulling action. Additional objects will appear from the following description and claims.

The invention will now be described in connection with the accompanying drawings, in which:

Fig. 1 is a side elevation, partly broken away, of a four-cup mulling mill constructed in accordance with my invention;

Fig. 2 is a detail of one form of platen mount- Fig. 3 is a transverse section through a portion of the mechanism shown in 1; taken on line 33 of Fig. 4;

Fig. 4 is a top plan view of the mulling disk, taken on line i-A of Fig. 3 and partially broken away;

Fig. 5 is a top plan of the machine shown in Fig. 1;

Fig. 6 is a fragmentary section on line 6-5 of Fig. 3;

Fig. 7 is an enlarged detail of the grinding portion of one of the cups; Fig. 8 is a section on line 8-8 of Fig. 7; and Fig. 9 is a sectional detail of a modification.

The machine is carried upon a plurality of uprights [0 from which is supported, as by brackets I I, a generally circular support l2. This support is hollowed out as at E3 to form a drip pan for cooling water as will be described below, and at its periphery carries a plurality of rolls M to support a rotatable platen 15. In order to stant temperature.

secure an even bearing of all of the rolls on the platen they are preferably made individually adjustable in the manner shown in Fig. 2. For this purpose the member I2 is provided with outwardly extending bosses l6 into each of which a screw ll is threaded. Adjustable upon the screw is an eccentric bearing member it upon which roll It may turn, this eccentric portion having a flange l9 held in place by the screw head 26 and serving to adjust the eccentric and also to hold the roll in place.

The member I2 has a vertical opening 2| in its center in which anti-friction bearings 22 are mounted so as to support a vertical shaft 23.

1 The platen I5 is keyed to this vertical shaft at at so that as the shaft is turned the platen will be rotated upon the supporting rolls I l. The top of the platen is formed with an annular ledge 25 and with interrupted intermediate and inner ledges 26 and 2'! upon which the mulling disk 28 rests. The mulling disk may in certain cases be made integral with the platen, but as it is usually desired to form it from bonded abrasive the separate platen is desirable. The several ledges are preferably connected by ribs 29 at a lower level so that the whole interior of the platen below the stone may form a single large water chamber 30, by circulation of water through which the disk may be kept at a con- Water is supplied to this chamber through a vertical pipe 3| threaded into a socket 32 in the upper end of the shaft 23, this socket communicating with the spaces 33 between the ledges 21 through radial holes 34. The water passes radially outwardly and runs oif through downwardly extending tubes 35 arranged in the ribs 29 adjacent the ledge 25. The tubes 35 extend into the drip pan l3, which collects the water and delivers it through a suitable drain 36.

The large mulling disk 28 rotates with the platen, being held to the shaft 23 by a large key 31. Resting upon it, but held against bodily rotation with it, are a series of annular mullers w shown in detail in Figs. 7 and 8, and generally formed of bonded abrasive. These latter are held in shouldered portions 4| of cup members 42 which may conveniently be formed of cast iron. As will be seen from Fig. 3, the shoulders of the cup members are so formed as to permit the mullers alone to contact the large disk 28. These cup members, however, serve both to exert the necessary pressure between the mullers and the disk and as receptacles into which the pigment and vehicle to be mulled are placed.

The cup members have inwardly extending lateral ribs 43 supporting a hub member 44 spaced out of contact with the disk 28, the ribs preferably being angled to exert a downward propelling action upon the material within the cup. An anti-friction bearing 45 of the lateral thrust type is seated in the upper part of each hub and receives centrally a plug 45. The plug has a conical depression in its upper surface which receives the pointed end 41 of a rod 48 slidable vertically in a hub portion at formed in a spider 58 supported from the uprights It.

To regulate the pressure of the annular grinding stones against the large disk the rods 48 are forced downwardly with a regulable pressure. For this purpose a lever is pivoted to the spider at 52 adjacent each of the rods and carries a screw 53 in contact with the upper end of the rod. A weight 54 slides on each of the levers and is engageable in any one of a series of notches 55 therein. It will be seen that by shifting the weight the downward force exerted on the annular mullers can be regulated accurately and held constant irrespective of the nature of the material being mulled, and that by reason of the fact that this downward force is transmitted to the cups through the pointed lower ends 57 of the rods only it'will be distributed throughout the periphery of the mullers with perfect uniformity.

The machine is operated by gearing 6i] driven from a pulley 6! or any other suitable source. This causes the large disk to revolve and due to the fact that the outer part of the large disk moves faster than its inner portion the mulling cups will be caused to revolve in the direction of the arrow G2 in Fig. 5. If material to be ground is placed inside of the cups it will gradually be carried underneath the annular mullers and distributed upon the surface of the large disk. As the latter rotates, the mulled material may be pushed off it by doctor blades 63 onto a ledge 54 of the platen, from where it may be gathered by a doctor blade 65 and delivered into any suitable receptable.

One advantage of the described construction is that the annular mullers are held against the flat disk in such a way that they can be rotated by it on their own axes at the natural speed determined by their size and position, and that the pressure on the mullers is kept centralized and without restraint upon their tendency to lie flat on the disk. This results in the mullers and disk grinding themselves so as to present optically flat mating surfaces, whereas other types of mulling or grinding machines require frequent dressing. It may be advantageous in certain cases to constrain the several annular mullers to rotate at identical rates, preferably without varying their freedom as a whole to rotate at their natural speed. This prevents local conditions from causing an abnormal speed of rotation of one of the mullers, and insures uniformity in the product delivered by the several mullers. provided with a ring gear 70 meshing with a For this purpose each muller is floating ring gear ll held on a hub 12 of the spider 50 by a detachable flange 13. Since the ring gear H is free to rotate the only constraint it imposes on the mullers is that they all rotate at the same speed, whatever that may be with respect to the disk.

I claim:

1. A mulling mill comprising a mulling disk, means for revolving the disk upon a vertical axis, a plurality of paste retaining cups, each bearing an annular muller upon its lower surface in face contact with the disk, an arm pivota'lly carried above each of the cups, a weight adjustably mounted on each arm, a rod extending from each arm into one of the cups, and a universal bearing between each rod and its respective cup.

2. A mulling mill comprising a mulling disk, means for revolving the disk upon a vertical axis, a mix retaining cup having an annular mulling surface in face contact with the disk, an arm pivoted above the cup, a weight adjustably mounted on the arm, a rod extending from the arm into the cup, a universal bearing within the cup and engaging the rod, and an openwork support carried by the cup and carrying the bearing and comprising slanting vanes, said support acting to agitate and force downwardly material within the cup as the latter is rotated upon its individual axis by frictional contact with the disk.

3. A mulling mill comprising a frame, a platen, anti-friction supports on the frame for the platen, means for rotating the platen, a mulling disk on the platen, a plurality of mix retaining cups, each having an annular mulling surface in face contact with the disk, a non-rotating spider carried by the frame above the platen, an arm pivotably carried by the spider above each of the cups, a weight adjustably mounted on each arm, a rod slidable in the spider under each arm and extending into the respective cup, an openwork support within each cup comprising spaced slanting vanes assisting the downward passage of mix as the cup rotates, a combined radial thrust anti-friction bearing carried by said support, and a combined radial-thrust connection between the rod and the bearing.

i. A mulling mill comprising a frame, a platen, anti-friction supports on the frame for the platen, means for rotating the platen, a mulling disk on the platen, a plurality of mix retaining cups, each having an annular mulling surface in face contact with the disk, a non-rotating spider carried by the frame above the platen, an arm pivotably carried by the spider above each of the cups, a weight adjustably mounted on each arm, a rod slidable in the spider under each arm and extending into the respective cup, an open-work support within each cup permitting the downward passage of mix, a combined radial thrust anti-friction bearing carried by said support, and a combined radial-thrust connection between the rod and the bearing. 7

DANIEL E. HENNESSY.

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