US3390867A - Machine for working on materials - Google Patents

Description

July 2, 1968 5.0. RIEDEL ET AL I MACHINE FOR WORKING ON MATERIALS Filed March 7 1967 msTANcEur ANGLE e PLOTTED \N DEPENDENCE OF THE DEPTH OF PENETRRTION t \NVEN ORS zvm m & m Eu 0 DL. T mm M R. R o a mm W m N Y 8 w 0 5 m l\ t w w m United States Patent 0 3,390,867 MACHINE FOR WORKING ON MATERIALS Erich O. Riedel, Locarno, Switzerland, and Hubert P. Hageliicken, Wuppertal, Germany, assignors to Carl K. Walther, Wuppertal-Vohwinkel, Germany Continuation-impart of application Ser. No. 461,249, June 4, 1965. This application Mar. 7, 1967, Ser. No. 621,227 Claims priority, application Germany, June 6, 1964,

10 Claims. c1.2s9-si ABSTRACT OF THE DISCLOSURE A machine, for use in working on materials comprises a revoluble receptacle that has a yieldable wall, and is subjected to the action of displacing means that exert an inwardly directed pressure against one or more portions of the wall thereby bulging that portion or portions inwardly to such an extent that the materials moving normally in the receptacle in a substantially circular path will be moved off said path in a track in a direction towards the interior of the chamber.

This application is a continuation-in-part of our application 461,249 filed June 4, 1965, now abandoned.

The invention relates to machines, for use in working on materials, and relates more particularly to machines that include a rotatable receptacle of the type often referred to as a rotating drum, for subjecting materials to various working operations.

For example, rotating drums of this type are used for materials or mixtures of materials to be comminuted either alone or with additional heaters, such as steel balls, which are inserted into the interior chamber of the rotatable receptacle and are by the movement of the receptacle put into a relative movement, that results in the comminuting.

Such rotatable receptacles are also used for mixing or kneading processes, and also here the movement of the receptacle is used to create a relative movement of the materials inside the receptacle to give the necessary mixing and/or kneading effect.

Rotatable receptacles of this type are furthermore used to put coating onto materials by putting the materials as well as the coating materials into the interior of the receptacle and operating the receptacle by rotating it.

It is furthermore known, to use such rotating drums for the surface working of materials, such as work pieces, by inserting into the receptacle not only the work pieces but also grinding and/or polishing materials, and these are put into relative movement to each other by the movement of the receptacle, and thus act in a grinding, polishing or otherwise edge removing manner.

Reference is had to the patent to William A. Retzlaff, No. 3,144,242, which shows a machine for storing, transporting and final mixing of cementitious material; it has a rotating drum that is made of waterproof material such as neoprene and runs on rollers, for the purpose of mixing the materials on the interior of the rotating drum. In order to ensure that the bag will hold its cylindrical form during the mixing operation, the rotating drum is inflated with air under pressure. Internal veins or fins are provided which project radially inwardly from the side wall of the rotating drum and which extend along its entire length, to improve the mixing action that takes place within the drum as it is revolved.

It is among the principal objects of the invention to 3,390,867 Patented July 2, 1968 "ice avoid the drawbacks of the prior art, to increase the intensity, effectiveness and efliciency of operations of this type machine that includes a revoluble receptacle, and to shorten the time of operation.

It is another object of the invention to provide a machine of this type with a receptacle that has a wall of yielding material and which is subjected at least at a portion to an inwardly directed pressure resulting in an inward bulging of that wall portion.

It is a further object of the invention to provide such a machine with a rotatable receptacle that is driven with such a rotational speed that suffices in order to subject the materials inside the receptacle to a pressure exerted by centrifugal force; and the displacing means that press the aforesaid portion inwardly will result therein that the materials or material mixtures will be moved off their normal circular course at that bulging portion and proceed in a direction towards the interior of the receptacle.

It is still another object of the invention to provide such a machine in which the centripetal force will overcome at said portion the centrifugal force; so that the material moved off the interior surface of the receptacle wall will be directed off its previous course and will strike depending on the magnitude of these forces, with a certain impact a different part of the interior of the receptacle.

Further objects and advantages of the invention will be set forth in part in the following specification and in part will be obvious therefrom without being specifically referred to, the same being realized and attained as pointed out in the claims hereof.

With the above and other objects of the invention in view, the invention consists in the novel construction, arrangement and combination of various devices, elements and parts, as set forth in the claims hereof, certain embodiments of the same being illustrated in the accompanying drawings and described in the specification.

The instant invention provides, generally speaking, for a displacing of the materials inside the rotating drum from their normal course by an internal bulging of the receptacle wall that is caused by displacing means, such as one or more rotatable rolls. This bulging has the effect that the wall will deviate from its previous substantially circular course inwardly, and the materials will move along therewith, including the change in direction. Thereafter, however, the wall will return to its previous non-bulging position, but the materials will continue, due to the previously applied centripetal forces, in the direction off the previous course, and move towards the interior of the receptacle chamber, .and will there strike a different point of the chamber. At the point of impact, new forces will be generated, which cause a mutual effect of the materials or material mixtures onto each other. Where several such displacing rolls are provided, there will occur a multiplicity of the effects just mentioned.

The receptacle wall is yieldable, and may be made of rigid link members which are connected to each other in an articulate manner, so that the individual link members may be displaced from their normal circular course. In accordance with a preferred embodiment, the yieldable wall of the receptacle is made of thin steel. In accordance witha preferred embodiment, furthermore, the dis-placing members are formed as rolls, which exert an inwardly directed pressure against the yieldable wall of the receptacle.

Previously, it was the prevailing opinion that rotating drums of this type could be made only from rubber or rubber-like material. This opinion appeared to have been guided by the thought that even at a suflicient centrif- 3 ugal acceleration of the rotating drum, the depth of penetration of the displacing means into the wall of the rotating drum had to be rather large.

The instant invention, however, has as one of its bases the recognition that at a diameter of the rotating drum of 500 mm., all there is needed is a penetration depth of about 1 mm., in order to achieve a path of movement of the piece of material taken off its previous course and directed towards the interior of the chamber, of about 78 mm. This recognition made it possible to use other yieldable materials for the rotating drums than rubber or rubber-like matter. The instant rotating drums, as a matter of fact, are rotated sufiiciently rapidly that the gravitational field is overcome by the rotational force; and in such rapidly rotating drums, rubber is not usable. Rubber and rubber-like materials, as a rule, are poor heat conductors. By dislodging portions of the wall inwardly into bulges, there is produced a large volume of heat, that results from the kneading work between the receptacle and the displacing roll. This heat, however, would destroy in a brief time the receptacle wall, if it were made of rubber or rubber-like material.

In accordance with the instant invention, thin steel may be used as the yieldable wall for the receptacle, having a thickness of but a few millimeters. For instance, a steel sheet of 1.25 mm. thickness with a receptacle diameter of 1200 mm. has given satisfactory results, because steel will rapidly impart the developing heat to the surrounding air.

The instant invention furthermore provides that the displacing rolls form with the axis of the rotatable receptacle either similar or dissimilar angles, and for adjustment of the roll positions, as well as for either intermittent pressure exertion by the rolls against the re ceptacle wall, and/ or an adjustable pressure exerted by the rolls, and penetration of, the rolls relative to the receptacle wall.

The instant invention furthermore offers the possibility to provide for impact actuation between the materials including mixtures of materials that have been directed inwardly from the previous course, as explained in the foregoing, and pieces which are not part of said rotating materials including the aforesaid mixtures of the materials. For this purpose, the instant invention provides for holding or guiding means inside the receptacle, which are assigned to the aforesaid pieces within the receptacle, and which will be bombarded by the aforesaid materials including the mixture of said materials in the aforesaid direction towards the interior of the receptacle. These pieces may perform Within the receptacle a movement of their own, either synchronously with the receptacle circularly and/ or may wander inside the receptacle interior, in order to expose their entire surface to the bombardment.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description, taken in connection with the accompanying drawings, in which:

FIG. 1 is a side elevational view of a machine for working on materials in accordance with an embodiment of the invention;

FIG. 2 is a sectional view taken on the line IIII of FIG. 1;

FIG. 3 is a sectional view, similar to FIG. 2, but being modified in that the displacing means are located closer to the center of the receptacle, as compared to FIG. 2;

FIG. 4 is a sectional view similar to FIG. 2, but embodying a modification;

FIG. 5 is a large scale fragmentary schematic view of a receptacle and a roll, indicating the penetration by the roll into the wall of the receptacle and the occurring forces, direction of forces and movements of the materials inside the receptacle; and

FIG. 6 is a graph showing the distance of travel of the material particles, and the angle of impact of said material particles, in dependence of the depth of penetration into the receptacle wall by the displacing roll.

In carrying the invention into effect in the embodiments which have been selected for illustration in the accompanying drawings and for description in this specification, and referring now particularly to FIGS. 1 and 2, there is provided a machine for working on materials, that includes a receptacle body 1 which rotates about the axis X-X. The body 1 includes a wall 2 that is yieldable and is formed substantially cylindrically about the axis X-X. In accordance with a preferred embodiment, as previously explained, said wall 2 is made of thin steel. Displacing means are provided, such as rotatable rolls 3, which are disposed in the circular path of the wall 2. The rolls 3 serve to displace portions of the wall 2 inwardly, for instance, at the locations shown in FIGS. 2 and 3, it being understood that the amount of penetration shown in FIGS. 2, 3 and 5 are exaggerated. By such inward displacement, the wall portions adjacent the rolls 3 will form inward bulges, as shown exaggeratedly in FIGS. 2, 3 and 5, and at these portions the wall 2 will be displaced from the preceding and succeeding substantially circular path.

In the embodiment of FIG. 2, the receptacle 1 includes grinding and polishing means 4, as well as work pieces 5, the surface of which is to be smoothed by the impact with the grinding or polishing means 4. The speed of rotation, indicated by an arrow A in FIGS. 4 and 5, is sulticiently large that in the absence of the displacing rolls 3, the grinding or polishing means 4, as well as the work pieces 5, due to the centrifugal force action, would be carried along as an internal layer of substantially circular shape in a substantially circular path by the wall2.

The bulging displacement brought about by the displacing rolls 3, on the other hand, of the portions of the wall 2, bring about the result that the mixture of the grinding or polishing means 4 and the work pieces 5 upon approaching one of these bulges and the resultant displacement of the wall 2 itself, will likewise be displaced from its preceding substantially circular course and after such displacement will, in contrast to the wall 2 that resumes its previous path, proceed in the new direction towards the interior of the chamber, substantially linearly, and will strike the wall 2 on the interior of the receptacle at a different point. Thereafter, the wall 2 will again carry along that mixture until the next bulge, as best shown in FIG. 5.

Due to these changes in direction and impacts, the action of the grinding or polishing means onto the work pieces is greatly increased and rendered far more effective, and hence a more intensive surface treatment is achieved.

It is possible to put only the grinding or polishing means 6 into the chamber (see FIG. 3), rather than including in the chamber a mixture of grinding or polishing means 4 and the work pieces 5, as in FIG. 2, so that only the grinding or polishing means 6 will participate in the rotating movement and the subsequent deviation from the rotating movement. In this case the work .pieces may be held by holding or guiding means (not shown) either fixedly or movably. The work pieces may also be turned within the receptacle, in order to expose the entire surfaces to the impact by the grinding or polishing means 6. In order to form a zone within the receptacle 1, in which a particularly intensive operation takes place, the displacing rolls 3 may be so arranged relative to the receptacle 1, that they displace the wall 2, as well as the grinding or polishing means 6, more strongly than as shown in FIG. 2, so that there will be created crossing tracks of grinding or polishing means 6 moving in a direction towards the interior after having been moved off the circular movement. In such an event it is advantageous to arrange the work pieces at the crossing portions of these tracks.

Where it is desired to subject the surfaces of the work pieces to other operations but grinding or polishing, for instance to descale them, or the like, or to render the surfaces more compact, the grinding or polishing means 6 may be replaced by other bombarding means, such as heaters or wire clippings, steel balls, sand or the like. They will operate in a similar manner as has been described in connection with the grinding or polishing means.

As previously mentioned, the instant machine may be used instead of for the surface treatment of the work pieces, for the mixing, kneading or grinding operations within the receptacle 1; for this purpose, the materials to be mixed, or such materials which are to be kneaded or comminuted, are filled into the receptacle 1. For comminuting, it is particularly useful to add heaters to the materials to be comminuted, such as balls or the like. Lastly, it is also possible to use the instant machine for providing coatings onto pieces, such as pills or the like.

As the materials including the mixtures of materials, due to the centrifugal force that occurs in the rotating receptacle, are carried along by the receptacle wall 2, it is possible to arrange the axis XX of the receptacle 1 either upright or at an angle thereto. Furthermore, the receptacle may be open on one side or on both, or be closed.

The invention furthermore provides for various forms of receptacles 1, including such receptacles that have an arcuate generating line, in order to improve the compactness and durability of the receptacles in the zones between the displacing rolls 3.

The graph 6 is based on calculations made in accordance with FIG. 5, the latter showing the displacing roll 3 penetrating to a depth t and having a radius r, and the receptacle 1 having a wall 2 and a radius R; 2' indicates the wall as it would be without penetration, showing the depth 2 of penetration. The particles inside the receptacle 1 will move substantially cylindrically with the wall 2, until they reach the bulge indicated at 7. The particles will leave the bulge 7 at the point 9 in a track throughout a distance w, and will strike the wall 2 at a point 8 at an angle e. The graph of FIG. 6, in which all the distances are in millimeters (mm.), is based on a radius R of the receptacle of 500 mm., a radius r of the roll of 80 mm., a radius R of a curvature, that is an approximation of the actual curve between the normal periphery and the bulge of the wall 2, and equals about 200 mm., and a constant rotational speed of the receptacle 1 in the direction A.

The graph of FIG. 6 includes the following calculated values:

The actual rotational speed of the receptacle 1 is variable and may, for instance, have from about 90 to about 150 r.p.m.

In FIG. 2, the rolls 3 have been shown parallel to the central axis of the receptacle 1 (indicated XX in FIG. 1). In the modification of FIG. 4, the roll 3 has its axis YY inclined to the axis X--X of the receptacle 1; the receptacle 1 is turning in the direction A. As shown in solid lines in FIG. 4, the roll 3a is inclined in one direction relative to the receptacle; as indicated in broken lines at 3a, however, the roll 3a may be adjusted to a different angular position of its axis YY relative to the axis In a similar though modified manner, the roll 3b is shown with its axis ZZ inclined at adjustable angles relative to the plane of the axis XX of the receptacle 1; in solid lines, there is shown one angular position, and in broken lines at 3b there is shown another differently adjusted position of inclination of the axis Z-Z of the roll 3b relative to the plane of the axis XX.

The roll has next to it an arrow B. The arrow B indicates that the roll may be adjusted as to its depth of penetration, for instance to change the penetration from that shown in FIG. 2 to that shown in FIG. 3. Furthermore, the arrow B indicates that the roll 30 may in addition to adjustment of the penetration, or in lieu thereof, be applied intermittently.

All the rolls may either be parallel to the axis XX, as shown in FIG. 2; or some or all the rolls may form an angle with the axis XX; and these angles may be the same or different for each roll relative to the axis XX; some or all of the rolls may be made adjustable, as shown in connection with the rolls 3a and/or 312, or in other similar manner, and/ or may be made adjustable as shown in connection with the roll 30 regarding penetration and/or be operated intermittently.

We wish it to be understood that we do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

Having thus described the invention, what we claim as new and desire to be secured by Letters Patent is as follows:

1. In a machine, for use in working on materials, the combination of a receptacle structure comprising a wall formed substantially cylindrically about an axis and comprising a yieldable wall and defining on the interior an unobstructed chamber for said materials, said receptacle being rotatable about said axis whereby the materials will normally be rotated in said chamber and be subjected to centrifugal force and thereby normally proceed in a substantially circular course adjacent the inner surface of said wall, and displacing means near the external surface of said wall being operable to exert inwardly directed pressure against at least a portion of said wall by bulging said portion inwardly sufficiently so that at said portion centripetal force will be applied to said materials overcoming the centrifugal force and moving said materials off their course and in a track in a direction towards the interior of said chamber.

2. In a machine, as claimed in claim 1, said displacing means comprising at least one rotatable roll operable to be applied to said wall portion for pressing said wall portion inwardly.

3. In a machine, as claimed in claim 1, said displacing means comprising a plurality of rotatable rolls, each roll being operable to be applied to a separate wall portion of said receptacle exerting inwardly directed pressure thereagainst, whereby said receptacle will have a plurality of inwardly bulging portions.

4. In a machine, as claimed in claim 3, the axes of rotation of all said rolls being substantially parallel to each other and to said receptacle axis.

5. In a machine, as claimed in claim 3, at least some of said rolls being angularly oifset relative to said receptacle axis.

6. In a machine, as claimed in claim 5, said yieldable Wall being composed of thin steel having a thickness of about 1.25 millimeters, said receptacle structure having a diameter of about 1200 millimeters.

7. In a machine, as claimed in claim 5, at least one of said off-set rolls forming an angle with said receptacle axis different from that of at least one other off-set roll.

8. In a machine, as claimed in claim 3, said rolls being adjustable in their positions relative to the receptacle axis.

9. In a machine, as claimed in claim 1, said displacing means being operable to exert the inwardly directed pressure intermittently against said portion.

10. In a machine, as claimed in claim 1, said displacing means being adjustable to adjust thereby the amount of pressure exerted by, and penetration of, said displacing means relative to said receptacle wall.

(References on following page) 8 References Cited FOREIGN PATENTS UNITED STATES PATENTS 132;} lGrleatBrifain- 1,531,651 3/1925 Geiger 259-72 1078379 3/1960 333 3,091,435 5/1963 Pease 259 72 3,144,242 8/1964 Retzlafi 259-176 ROBERT W. JENKINS, Primary Examiner.

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