US3079645A - High speed molded wheel and process therefor - Google Patents

Description

March 5, 1963 w. J. cosmos 3,079,645

HIGH SPEED MOLDED WHEEL AND PROCESS THEREFOR Filed Nov. 25, 1957 2 Sheets-Sheet 1 a 1 i V 3 21 P J 5. 4.5 J 36 I J Y J, jg INVENTOR. 19 5 1 1/ J6 /zZ/z'afiz J [as/mas.

w. J. cosmos 3,079,645

HIGH SPEED MOLDED WHEEL AND PROCESS THEREFOR 2 Sheets-Sheet 2 M BY March 5, 1963 Filed Nov. 25-, 1957 llnited States fP atent 3,979,645 HIGH SPEED MGLIEED WHEEL AND PROCES THFJREFGR William 3. Cosmos, 651 Market St, Waulregan, ill. Filed Nov. 25, 1957, Ser. No. 698,669 4 (Zlahns. (62. 18-49) The invention relates to improvements in industrial wheel units and more particularly to high speed contact wheels for grinding and polishing machines employing revolvable coated abrasive belts or sleeves; roller sections for industrial rollers; expanding wheels for mounting abrasive belts and sleeves; and to the method of manufacture of such wheels and wheel units. In the use of a high speed contact wheel an abrasive belt is trained over and revolved at a high speed around-one or more such wheels and it is eilectively supported thereby for the presentation of the work thereto. Such Wheels, as well as wheel units, roller sections and expanding wheels, have a resiliently yieldable rim or working periphery, which, in some applications, is treaded to accommodate variations in a belt trained thereover and/or in the work presented thereto, to facilitate cooling and to prevent premature wearing of the belt, and marring, marking or mutilation of the work, to make the wheel more or less aggressive, and to provide firm binding of the belt or sleeve over the wheel while it is in rotation.

Wheels, roller sections, wheel units and expanding wheels of this general character are operated at high speeds, usually in excess of 1500 revolutions per minute, and they comprise, generally, a mounting hub and concentric flanges forming a peripheral surface connected. to the hub by a web. More specifically, one example of such a prior type of wheel structure has the hub, web and peripheral surface formed as a unit, as by casting; the flanges thereof extending in opposed directions on each side of the web. The resiliently yieldable rim or working periphery is wrapped around and bonded to the outside circumferential face or" said peripheral surface. The rim, it smooth surfaced, is then milled or otherwise formed in any conventional manner with circumferential and/or laterally directed channels, grooves or slots, so as to provide a peripheral working surface having a multiplicity of ribs, lands or islands, each having the requisite resiliency and yieldability to function for its intended purpose. The working surface is then dressed so as to insure uniformity of diameter and dynamic balance.

The construction of such a known type of industrial wheel structure involves an excessive amount of costly labor and time, and it is therefore, an object of the invention to provide a novelly constructed inexpensive industrial wheel structure of the characte herein referred to.

Ordinary industrial wheels or wheel units of known types tend to wobble to some degree, particularly when used singly, while operating with a high power output, primarily because of the inherent resiliency of the stock comprising the web. Such wobble causes lateral shifting of a belt trained thercover, and furthermore, there is sound generation, uneven wear on the belt, sleeve, arbor, or wheel unit itself, and the danger of wheel explosion is great. It is therefore another object of the invention to provide a wheel structure with novel means to prevent such wobble.

During high speed operation of a wheel, the bonded resiliently yieldable peripheral rim is subjected to tremendous centrifugal forces which tend to expand the rim outwardly radially and should the bonding of the rim to the metal web flange be inadequate, or should there be air pockets in the rim material, the rim is liable to become ruptured and disintegrate, in which event serious injury may result to the operator and the machine damice aged. The present method of construction and the resulting structure of the wheel itself is such that the rim is adequately bonded, not only to the peripheral web flanges, but also is integral with a body of the same material that is held between and bonded to the opposed faces of the web discs and consequently is so reinforced as to withstand the damaging influence of the centrifugal forces generated during use. it is therefore another object to provide a wheel structure of the character described with novel means to prevent disintegration by reason of centrifugal forces.

Another object is to provide a novel method and means for forming an integral wheel structure embodying the novel features herein described.

Hcretofore, considerable difliculty and expense has been involved in making wheel structures having peripheral working rims of diderent widths and with a web proportioned in thickness to the rim width so as to insure adequate rigidity to the finished wheel. Such variation occurs in instances of integral wheels, segmental wheel units, roller units, or expanding wheels having different face widths and web thicknesses. These can be made in the same mold or dies with but slight modification or substitution therein. The modification or substitution is easily and quickly accomplished by practice of the herein disclosed novel method of construction, and it is therefore another object of the invention to provide a novel method of manufacture which is readily adaptable for making contact wheels or wheel elements of diderent widths and having dlfierent degrees of rigidity in the web portion thereof.

Another object is to provide a novel sectionalized industrial roller.

With the foregoing and other objects in view which will appear as the description proceeds, the invention consists of certain novel features of construction, arrangement and combination of parts hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the form, proportion, size and minor details of the structure may be made without departing from the spirit of sacrificing any of the advantages of the invention.

Referring to the drawings in which the same characters of reference are employed to indicate corresponding or similar parts throughout the several figures of the drawing:

FIGURE 1 is a diametrical section view of the novelly assembled contact wheel.

FIGURE- 2 is a diametrical sectional view of the die or mold assembly, showing the dies in open position and the wheel material positioned therein.

FEGURE 3 is a view similar to FIGURE 2, showing the die assembly closed.

FlGURE 4 is a peripheral view of a segmental contact wheel, showing parts in section.

FIGURE 5 is a peripheral view, partly in diametrical section, showing an expanding wheel embodying the features of the invention.

FEGURE 6 is a peripheral view of an industrial roller built up of removable and interchangeable sections each constructed by the herein disclosed method.

FEGURE 7 is a fragmentary diametrical sectional view of a wheel unit, embodying a modified form of con struction.

The high speed contact wheel and wheel units disclosed herein and embodying structure for overcoming the aforementioned disadvantages and characteristics of known types of wheel structures, is made by pressure molding in a heated die assembly. It comprises essentially, a pair of peripherally flanged web discs tabricated, as by stamping, from sheet metal stock, which are seated in the open die, and which have a mass of unvulcanized rubber, natural or synthetic, of predetermined volume placed therebetween. The dies of the die assembly include a tread or rim forming cavity and when the dies are moved toward one another (usually at a pressure of approximately 2090 lbs. per square inch) as is common practice during the molding operation, the unvulcanized rubber mass is distributed evenly between the web discs at a thickness determined by the setting of'the discs, and the rubber extruded from between the discs flows outwardly radially into and fills the rim forming cavity which may or may not include landor tread forming configurations; The whole is then heat treated or cooked at temperatures ranging-from about 280 F. to 320 F. for a period of time required to vulcanize the rubber and to bondit firmly to the contacted metal surfaces of theweb discs. When the wheel structure is removed from the die it is mounted on-an arbor :androtated :at high speeds, and dressed. The

amount of .dressing required is nominal and is primarily for the purpose .of-obtaining a dynamic balance in the wheel, and for removing the central circumferential area of thejperipheral worksurface which bulges outwardly at the circumferential center owing to applied centrifugal forces. The dressed wheel unit structure, when idle, will therefore have a slightly concave surface laterally, which surface assumes a flat condition during rotation of the Wheel.

The contact wheel illustrated in FIGURE 1 is fabricated in anovel manner to be described presently. It comprises a pair of circular web plates 11, fabricated, as bystamping, from heavy guage sheet metal stock, having-aligned axial openings 12 and each is formed on its outer perimeter with a peripheral flange 13. When assembledin a contact wheel, the web plates 11 are maintained in spaced relation one to the other by the presence of a layer of rubber14 of predetermined thickness therebemeen and with their peripheral flanges extending outwardly in opposite directions. These flanges constitute a peripheral surface upon which is bonded a resiliently yieldable rim or working periphery 15 that is integral with the intermediate layer of rubber 14. There is thus provided a contact wheel 10 having a resiliently yieldable working periphery or rim that is bonded firmly to the plate flanges '13 and is integrally connected to a'layer-of rubber. 14 interposed between and bonded to the opposed facesof the plates 11.

The web plates 11 and the layer 14 therebetween constitute the web of vthe contact wheel and because of the increased thickness afforded said web by the presence of the interposed layer 14 and the fact that the said layer is 'bonded firmly to both discs, said web flat resists distortion while the wheel is in use and accordingly avoids wobble sooften present in wheels constructed according to prior known practices. The presence of the web layer 14 has other distinct advantages which will become apparent as the description proceeds. I

The contact wheel 10, as well as the wheel units and segments disclosed in FIGURES 4, 5, 6 and 7, and later described, disclosed in FIGURE 1, is fabricated in a novel manner'by a simple inexpensive one-step molding method illustrated in FIGURES 2 and 3. The entire wheel is made in one integrated body of metal and rubher by-a moldingprocess in a heated die assembly generally indicated at 16. As shown, the die assembly includes a lower die 17 which-is'comprised of a central die portion IS'and'asurrounding die portion or collar19, and an upper die 21. One ofthese dies 17 or 21 is stationary, while the other one is carried on a vertically recip-.

rocal hydraulically plunger (not shown) for movement vertically toward and awayfrom the first named die.

The said upper-die 21 has a downwardly facing diesurface formed with an annular downwardly offset surface 22 Ma diameter'corresponding to the diameter of a web plate 11 and terminating at its perimeter in a shoulder 23 and a surrounding annular surface 24. The shoulder 23 is of a height correspondingsubstantially to the width of the flange 13 on one of the web plates 11, so that when said one plate is placed over the surface 22, as is best shown in FIGURE 2, its flange 13 embraces the shoulder 23. The plate, and its flange, is thereby firmly backed by the die surfaces 22-23.

The other or lower die 17 of the die assembly is arranged below and in axial alignment with the upper die 21. The central die portion '18 is of such size as to receive the-reover the other web plate 11 which plate is seated on. the top face of the die and has its peripheral flange 13 snugly embracing an annular shoulder 25 surrounding said die surface. The surrounding die portion or collar 19 constitutes the peripheral rim of the die assembly and this collar is recessed on its upper face, as at 26, to provide a cavity in which thepworking surface or rim 15 of the contactwheel is formed in a manner to be described presently.

;As shown, the collar19 has an upper peripheral edge 27 which is carried into surface contact with the surrounding surface 24 of the upper die when the dies are in the closed position shown in FIGURE 3. The vertical inside annular surface 28 of the recess or cavity 26 may be smooth or itmay be formed with inwardly facing ribs or other mutually spaced projections 29 adapted to form the lands 31 on the working periphery or rim 15 which is formed in the cavity. In either event, the annular surface 28 terminates at its lower end in a planular surface 32 which is in horizontal alignment with the downwardly disposed free edge of the bottom web plate flange 13 car: ried on the central die portion 18.

If desired, either one of the dies 17 or 21 may carry an axiaLpost 33 adapted to extend through the axial openings 12 in the web plates 11 and telescope into an axial recess 35 in the other die when the dies are closed. In the present disclosure, the post 33 is carried by the lower die portion 18.

The molding of a wheel structure of the character 'herein disclosed involves the placing of a web .plate 11 on the lower die, as illustrated, while said dies are separated. The exposed face of said plate 11 preferably is roughened by sand blasting and is coated with a bonding adhesive. A predetermined mass 34 of unvulcanized rubber, natural or synthetic, is then placed upon the top surface of said web plate whereupon the upper die 21, carrying the other web plate 11, similarly coated, is oved relative to the die 17 andsufficient pressure is maintained on the mass sandw'iched-therebetween to compress the mass between the matched web plates 11. The pressurizing is accomplished in the presence of suflicient heat, supplied to the die assembly in any suitable manner, such as for example through ducts 36 therein, so as to maintain the rubber mass in pliable state.

Thedistance of travel of the upper die 21 relative to the lower die assembly 17 is limited by contact between the peripheral edge 27 of the surrounding die collar 19 with the surface 24. This distance is such thata predetermined quantity of the rubber mass is uniformly distributed between the web plate 11 with the excess rflowing outwardly radially into the cavity 26 so as to fcgm the working periphery or rim 15 of the contact w ee with a bond resisting powder or like substance. This powder or like substance is not brushed or wiped 'ofi by the radial flow of the extruded rubber into the cavity, as so often occurs when the mass is flowedinto the rim cavity through a feed opening in the peripheral wall of a die assembly. Any material in excess over the amount required to fill th space between the plates and in the cavity, may escape through bleeder holes 37 provided in an adequate number in the dies 1721, which holes also insure proper bleeding of any ,air trapped in the, die during its closing operation.

The walls of the cavity 26 are previously coated The closed die assembly, with the rubber properly distributed therein, is allowed to remain closed for a time required to effect vulcanization of the rubber and its firm bonding to the opposed faces of the web plates 11 and to the peripheral flanges 13 thereof, after which the die assembly is opened and the contact wheel 11 is removed.

'In the event that it is desired to provide hub portions 38 on each side of the web, this may be eflected during the molding operation. To this end, the upper die 21 and the die portion 13 of the lower die may each be formed with an axially concentric cavity 39 of such size as to receive therein one of the rubber hub portions 33. These hub portions are in surface contact with the outside faces of the respective web plates 11 and they are firmly bonded thereto during the pressurized vulcanizing operation previously described.

It should be quite evident at this time that applicant has provided a novel means for pressure molding a wheel structure wherein the rim or working periphery thereof is bonded firmly to the flanges of the metal web plates and is integral with the reinforcing layer of material distributed evenly between and bonded to said plates. The thickness of the interposed layer and the width of the rim may be varied by increasing or decreasing the ef fective depth of the perimeter wall 28 of the die collar 19'. Consequently, the herein disclosed process and method may be employed in the production of contact wheels, or wheel or roller units, of different face width and web thickness with but a slight variation in the equipment utilized.

FiGURE 4 shows a wide faced contact wheel composed of three wheel units 16a, each corresponding in structure to contact wheel it? in FIGURE 1, which are made by the herein disclosed method. Wheel unit Ida differs from wheel it in that web layer 1411 is thinner than web layer 14, and the Wheel unit has a narrower peripheral face or rim 15a. The thinner web layer 14a in a wheel unit is satisfactory because of tight face-to-face abutment of the units which affords rigidity to the wheel assembly.

FIGURE 5 shows an expanding wheel or hub unit ltib fabricated like the wheel and wheel units and lilo. Expanding wheel 10b is designed to receive slidably thereovcr working sleeve 41 which is firmly held during rotation of arbor 42 by centrifugal expansion of threaded periphery rim b. This wheel has a thick web layer 14b integral with rim 15b and bonded between web plates 1112.

FIGURE 6 shows an industrial roller 43 composed of several interchangeable and replaceable roll units 160, each of which is made by the within discribed method and which includes a thin web layer 24c bonded between web plates 11c and integral with its peripheral rim 15c. These roll units may be smooth surfaced, as shown, or they may be treaded as required.

FIGURE 7 shows a contact wheel unit fabricated in the same manner as the wheels and wheel units described hereinabove. In this instance the w eel unit includes a pair of sheet metal web discs 11d which are devoid of any peripheral flanges. Instead the peripheral margins of the discs are embedded in and bonded to the resilient peripheral rim 15d, as at 44, and said rim is integral with the resiliently yieldable web layer 14d interposed between and bonded to the opposed faces of the web discs.

A contact wheel, roller unit or wheel unit, made according to the teachings herein disclosed will have a longer wearing life and will not wobble during high speed working operations. When such wheels are rotated at high speeds required for eflicient use, the centrifugal force acting on the rimis transmitted throughout the entire body of the integral layer of rubber between the web plates with the result that such radial stress i substantially absorbed by the said layer thus reducing the CPI 6 likelihood of the rim tearing loose from the peripheral web flanges to which it is also bonded. Furthermore, the tensioning of the web layer between the Web plates to which it is bonded, in response to contrifugal force, not only reduces the inherent flexibility of the web structure, but it also exerts a lateral force inwardly on each web plate so as to increase the rigidity of said web plates and thereby eliminate all tendency of the web to wobble.

Although rubber, natural or synthetic, is suggested herein as the material best suited for the fabrication of the rim and the web layer integral therewith, other elastic or resilient.y compressible moldable material capable of tight bonding to metal may be used, and in a Wide range of densities for different specific uses.

It is believed that the invention, its mode of constrnction and assembly, and many of its advantages should be readily understood from the foregoing without further description, and it should also be manifest that while preferred embodiments of the invention have been shown and described for illustrative purposes, the structural details are nevertheless capable of wide variation within the purview of the invention as defined in the appended claims.

What is claimed and desired to be secured by United States Letter Patent is the following:

1. The method of making an industrial Wheel in a mold assembly which comprises the placing of a disc having a circumferential flange on its outer periphery and extending from one face thereof onto a mold surface with the flange extending downwardly, arranging a mass of unvulcanized rubber of predetermined volume upon the upper face of said disc, placing a like disc over the mass with its flange extending upwardly, pressing the discs toward one another to distribute the rubber uniformly between the discs and cause a portion thereof to be extruded outwardly radially beyond the flanged peripheries of said discs, molding the extruded rubber into a circumferential rim on the outside circumferential faces of said flanges, and finally vulcanizing and bonding the rubher to the opposed faces of the discs and to the flanges.

2. The method of making an industrial Wheel of a type having spaced circular metal plates bonded to an intermediate layer of rubber and a rim integral with said layer and embedding the peripheral margins of said plates, said method comprising placing one plate in a circular mold cavity having a rim forming cavity into which the peripheral margin of said plate projects, arranging a mass of unvulcanized rubber of predetermined volume on said plate, placing a second like plate over said mass with its peripheral margin extending into the rim forming cavity, pressing the plates toward one another to distribute the mass uniformly between the plates and cause a portion of said mass to flow outwardly radially and fill the rim forming cavity and embed the peripheral margins of the plates therein, subjecting the molded wheel to heat to vulcanize the rubber, removing the molded wheel, and finally mounting the wheel on a rotating arbor and dressing the peripheral surface of its rim.

3. The method of molding an industrial wheel of a type having spaced circular metal plates bonded to an intermediate layer of rubber and a rim integral with said layer and embedding the peripheral margins of said plates, said method comprising placing one plate in a circular mold cavity having a rim forming cavity into which the peripheral margin of said plate projects, arranging a mass of unvulcanized rubber of predetermined volume on said plate, placing a second like plate over said mass with its peripheral margin extending into the rim forming cavity, and then heating the said mold and pressing the plates toward one another to distribute the mass uniformly between the plates and cause a portion of said mass to flow outwardly radially and fill the rim forming cavity and embed the peripheral margins of the plates therein.

4. The method of molding an industrial Wheel of a type having spaced circular metal plates bonded to an intermediate layer of rubber and a rim integral with said layer and embedding the peripheral margins of said plates, said method involving the use of a circular mold having hub cavities and a rimforming cavity, placing rubber hub members one in each hub cavity, arranging a pair of like plates one over each hub member .with their peripheral margins projecting into the rim forming cavity, arranging a mass of unvulcanized rubber of predetermined volume between said plates, pressing the plates toward one another to distribute the mass uniformly between the plates and cause a portion of said mass to flow outwardly radially and around the projecting plate margins and fill the'rim forming cavity, subjecting the molded wheel to heat to vulcanize the 8. rubber and bond it to the plates, and finally dressing the peripheral surface of its rim. References Cited in the file pf-this-patent UNITED STATES PATENTS 1,686,142 Bansieur Oct. 2, 1928 1,947,695 Carthew Feb. 20, 1934 2,137,937 Smith Nov. 22, 193;; 2,439,90 .Pi ron Apr. 20, 19.48 2 ,674,897 Heinish Apr. 13, 1954' 2,760,378 Van Deventer Aug. 28,1956

7 FOREIGN PATENTS 1,101,559 France a Oct. 7, 1955 0 8 Germ n ---V---ly 1932 V 675,679 Great Britain July'l6, i952

Claims (1)

1. THE METHOD OF MAKING AN INDUSTRIAL WHEEL IN A MOLD ASSEMBLY WHICH COMPRISES THE PLACING OF A DISC HAVING A CIRCUMFERENTIAL FLANGE ON ITS OUTER PERIPHERY AND EXTENDING FROM ONE FACE THEREOF ONTO A MOLD SURFACE WITH THE FLANGE EXTENDING DOWNWARDLY, ARRANGING A MASS OF UNVULCANIZED RUBBER OF PREDETERMINED VOLUME UPON THE UPPER FACE OF SAID DISC, PLACING A LIKE DISC OVER THE MASS WITH ITS FLANGE EXTENDING UPWARDLY, PRESSING THE DISCS TOWARD ONE ANOTHER TO DISTRIBUTE THE RUBBER UNIFORMLY

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