US3662620A - Balance arbor assembly for buffing and like machine - Google Patents

Abstract

A work finishing wheel unit is clamped to a driving arbor by a pair of like holder collars between which conventional buff elements of the unit are held; and these collars each have an annular, dove-tail sectioned groove adjacent the outer periphery thereof. Mating balancing weights, also of dove-tail cross section, have slidable adjustment circumference-wise in the groove, being manually movable annularly to a desired balancing position, then fixedly clamped to the collar by a set screw to serve as a balancing counterpoise.

Description

United States Patent Carlson [451 May 16, 1972 [54] BALANCE ARBOR ASSEMBLY FOR BUFFING AND LIKE MACHINE George R. Carlson, 830 Cranbrook Road, Birmingham, Mich. 48009 22 Filed: July 2,1970

21 Appl.No.: 51,985

[72] Inventor:

[52] US. Cl v ..74/573, 51/169 [51] Int. Cl ..Fl6f 15/32 [58] Field ofSearch ..74/573;5l/l69 56] References Cited UN lTED STATES PATENTS 2,958,165 11/1960 Hofmann ..74/573X 430,270 6/1890 Cook ..74/573 Primary Examiner-Meyer Perlin Assistant Examiner-F. D. Shoemaker Attorney-Whittemore, l-lulbert & Belknap [5 7] ABSTRACT A work finishing wheel unit is clamped to a driving arbor by a pair of like holder collars between which conventional buff elements of the unit are held; and these collars each have an annular, dove-tail sectioned groove adjacent the outer periphery thereof. Mating balancing weights, also of dove-tail cross section, have slidable adjustment circumference-wise in the groove, being manually movable annularly to a desired balancing position, then fixedly clamped to the collar by a set screw to serve as a balancing counterpoise.

5 Claims, 2 Drawing Figures PATENTEDMAY 16 m2 3.662.620

FIG.| /35 INVENTOR. GEORGE R. CARL N -'-l'- BY I A TQRNEYS BALANCE ARBOR ASSEMBLY FOR BUFFING AND LIKE MACHINE BACKGROUND OF THE INVENTION 1. Field of the Invention The invention finds application in a wide variety of rotary buffing, polishing or like finishing wheel machines, as well as abrasive wheel or belt installations, in which it is desired to true the balance of a finishing wheel of one sort or another, or the rotative balance of a contact wheel backing an abrasive or like belt, thus to insure a most efficient and trouble-free operation thereof from the outset of use. The improvement also finds corrective application in many cases in which a relatively soft structured working buff is subjected to severe wear over a period of use resulting in a disturbance of the centrifugal balance of the wheel. This occurs commonly when the normal frictional wear on the wheel buffs (itself not necessarily distributed uniformly in even a purely rotative engagement) is compounded by a shifting of the work piece axially across the face of the wheel, or vice versa.

2. Description of the Prior Art I an unaware of any pertinent prior patented art of the general nature of the balancing assembly herein disclosed. However, makeshift attempts have been made in the past and continue to be made, to more or less crudely modify new and used finishing equipment to impart or restore rotative wheel balance. Thus it has been the practice, for example, in attempting to true up buffing or like wheels (often far from accurate as to balance as fabricated) to proceed, in the case of a unit comprised of an axial assembly of like buff components, by shifting the latter angularly relative to one another in an effort to compensate a lack of balance of one component by that of another, and so one. This hit or miss procedure usually leaves much to be desired in result; furthermore, even it is not available in the case of a wheel comprising a single, axially elongated buff component. This is also true in the case of an abrasive belt-backing roll or wheel, in which true balance is equally desirable. Abrasive flap-type wheels are usually offbalance as produced.

The problem also arises in instances in which an improper or uneven spray application of a dressing composition to a wheel or wheel component results in a loss of balance and resultant bounce in action. A complete new re-dressing of the wheel is normally in order.

Another corrective procedure has been to drill a hole or holes in a wheel hub to reduce its weight locally and correct the wheels balance. But even if the procedure is temporarily successful, normal operation may well again and soon render the wheel out of balance.

SUMMARY OF THE INVENTION As illustrated herein in a very simple version, the balanced wheel assembly comprises a pair of identical, hence reversely or interchangeably utilizable, holder annuli or collars of circular outline between which a series of buffing or polishing discs, for example, are clamped in the axial sense, one of the collars having axial engagement with an appropriate fixed shoulder or like stop formation on a rotary wheel drive shaft or arbor. The other collar is then held in clamped engagement with the opposite side of the buff unit, as by nut means threadedly engaged on a reduced cross section part of the arbor.

Pursuant to the invention, the identical collars each have one or more circumferentially adjustable balancing weights matingly received in a circumferential, axially outwardly facing groove of dovetail section on the exposed side of the collar and each weight, when positioned as desired, is clamped by a set screw to hold it in that position.

Thus, assuming that a finishing wheel unit, as typically constituted by an axial stack of relatively soft buffing discs, goes out of proper balance due to unequal or uneven wear, it requires only a brief stoppage of the equipment to enable an attendant to shift one or more of the balancing collar weights, including weights at either axial side or both sides of the wheel assembly, and set screw reclamp it in a circumferentially adjusted position. The same procedure applies to new wheels, of

course.

In such position, not only is the wheel imbalance compensated out in terms of unbalanced radial throw; but the use of corresponding independent weights on opposite sides of the buff unit enables the throw to be kept in perfect balance also in the axial sense, and without tendency to cant the centrifugal effect out of a plane at a true transverse angle to the axis of rotation.

While a wheel buff structure is herein shown and described, this type of finishing or polishing unit usage is simply illustrative; other more or less abrasive yet wearable wheel units may be balanced as desired by the provisions of the invention; as indicated above, and whether as an initial corrective treat mentor after the imbalance arises in use.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view, partially broken away, in a plane including the axis of rotation of the balanced arbor assembly ofthe invention, ie., in the plane ll ofFIG. 2; and

FIG. 2 is a fragmentary view in section along broken line 2 of FIG. 1.

DESCRIPTION OF A PREFERRED EMBODIMENT The wheel assembly of the invention, generally designated 10, is shown as being mounted on a driver shaft or arbor 12, a main full diameter portion 13 of this shaft having a somewhat reduced diameter, intermediate buff-mounting portion or section 14 which is threaded at 15 on its right hand end (FIG. 1). The arbor is further reduced suitably to a diameter at 16; and it is to be understood that the arbor portions 13 and 16 will be appropriately mounted in suitable bearing means, not shown.

A conventional stack unit or sub-assembly of fabric wheel buffs 18 is fixedly clamped between a pair of identical, but oppositely oriented, buffer holder collars 20 and 21, of which the left hand collar 20 surrounds the reduced diameter intermediate shaft section 14 with a reasonably close clearance, bottoming axially to its left (FIG. 1) against a stop shoulder 23 formed by the turning of the intermediate shaft section or portion 14. In this connection, it is to be understood, as indicated above, that the version 10 of the balanced wheel assembly herein dealt with is of a highly simplified nature; and that various stop or other provisions differing in nature from those herein shown may well be resorted to if seen fit, or if other considerations of design so indicate.

The opposite or right hand collar 21 serves as a clamping collar for the stack of finishing discs 18. Its relation radiuswise to the intermediate shaft portion 14 is the same as that of the stop collar 20, though oriented oppositely in the axial sense, as indicated above. Each of the collars 20 and 21 is provided with a pair of diametrically opposed keyways 25; and the intermediate shaft portion 14 is provided with diametrically opposed, axially elongated keyways 26; so that elongated keys 27 disposed in the radially facing keyways 25, 26 serve to lock the collars 20, 21 and the bufiing elements 18 clamped by the collars for rotation as a unit as driven by shaft 12. Collar 21 is typically held clamped in this driving relationship through the agency of a ring nut 28 applied to and taken up tightly on threaded shaft portion 15, with an appropriate annular shim or washer 29 interposed between nut and collar.

In accordance with the invention, each of the collars 20, 21 is provided on its axially outwardly facing surface or side, and quite closely adjacent the outer periphery thereof, with a dove-tail or truncated V-shaped circular groove coaxial with the shaft 24, the grooves being generally designated by the reference numeral 30 and affording an arcuate guide track for certain weights to be described. The grooves are of uniform cross section throughout almost a full 360 arcuate extent, opening outwardly between radially inner and outer angle edges 31, 32 and being bottomed by a 360 extending base surface 33. However, as best shown in FIG. 2, each groove 30 has its said edges 31, 32 interrupted at one small circumferential area or zone by radially opposed notches 34, 35, respectively. These may be considered to define, in effect, parts of a generally keystone-shaped access opening to the groove 30, such opening being indicated in dot-dash line in FIG. 2 and designated 36; its purpose is to be described.

Groove 30 is adapted to slidably receive one or more adjustable balancing weights 38, actually shown as three in number, which, in a perfectly balanced condition of the wheel structure 10, will naturally be disposed in 120 annular spacing from one another, or nearly so considering the weight factor introduced by opening 36. Each of the weights is of a generally keystone or truncated triangular outline at an outer, relatively massive body portion 39 thereof, at which its mass is in the main concentrated; and each weight 38 has an integral guide portion 40 of similar shape whose cross section is dovetailed to mate slidably at its angled radial edges within the correspondingly dove-tailed groove 30. The circumferential width of the portion 41 is slightly less than that of the access opening 36 to enable the weights to be easily introduced into and removed from the groove 30 as desired.

Each weight 38 is drilled and tapped through its radial midpoint to receive a small Allen or socket-head set screw 42 which, when tightly taken up in engagement against the base 33 of groove 30, will hold the associated weight tightly in an adjusted position. In the unlikely event of any of these set screws becoming loose, a further knurled head set screw 43 is tightly threaded into a tapped opening 44 in the base surface 33, centrally of the area of the latter projected by the access opening 36. Should a weight holding screw become loose, the screw 43 will prevent its dropping out of the groove 30 until the wheel unit is stopped and the weight is properly adjusted and secured.

FIG. 2 shows the balanced assembly with its three weights 38 positioned as depicted in solid line; while the weights are otherwise shown in dotted line in a typical position to which they may have been adjusted and reclamped to correct an unbalanced wheel condition arising from wear or the like. Naturally the spacing of any or all of the weights 38 may be altered as desired or found necessary, ie., they need not necessarily have approximately equal 120 spacing from one another.

The simple provisions described here render it unnecessary as in the past for an operator to correct a loss of proper wheel balance by resorting to some sort of crude procedure such as has heretofore been utilized, as briefly mentioned above. A loss of balance, particularly in the case of solid abrasive disk of a harder sort, may well result in a total destruction of an entire head structure. However, with the use of balancing means according to the invention it is only necessary for an attendant, with but a brief stoppage of wheel operation and at most employing a simple hand tool, to make a necessary balancerestoring adjustment.

What is claimed is:

l. A balanced rotative wheel structure, comprising a rotative driver or like operator member, a finishing or related wheel unit drivingly connected to said member and presenting an axially facing radial side surface, and means effecting the driving connection between said operator member and unit and enabling an adjustment of the rotative balance of said unit, comprising an annular member rotatable with said unit and provided with axially extending key means at least in part drivingly connecting the same with said operator member, said annular member affording a guide track in an outer axially facing side thereof concentric with the rotative axis of said structure, and an inner oppositely facing side for flush abutting engagement with said side surface of the wheel unit, at least one balance weight having a portion received by said track for arcuate adjustment relative to the latter and another portion projecting axially outwardly of said axial side of the annular member, and means to hold said weight in an annularly adjusted position in said track.

2. The structure of claim 1, in which there are two of said annular members, bein similar to one another and resentin the respective tracks t ereof on opposite axial sr es of sar wheel unit, and annular members clamping said unit therebetween to drivingly connect the latter with said operator member.

3. The structure of claim 2, in which said tracks are dovetail shaped grooves formed in axially outwardly facing surfaces of the respective part members, the portions of the I weights received therein being also of dove-tail shape to mate slidingly in the groove.

4. The structure of claim 3, in which the weights have set screw type means engageable with the respective annular members to hold the weights in adjusted positions.

5. The structure of claim 4, in which each of said grooves has at least one enlarged, outwardly facing access opening for the placement or removal of weights.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,662,620 Dated May 16, 1972 Inventor George R. Carlson It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In Claim 2, column 4, line 31, change "and" to -said-.

In the title, change "Balance to -Balanced-.

Signed and sealed this 25th day of July 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents FORM PC4050 (10459) I uscoMM-Dc 60376-P69 w US, GOVERNMENT PRINTING OFFICE C 959 0366-33

Claims (5)

1. A balanced rotative wheel structure, comprising a rotative driver or like operator member, a finishing or related wheel unit drivingly connected to said member and presenting an axially facing radial side surface, and means effecting the driving connection between said operator member and unit and enabling an adjustment of the rotative balance of said unit, comprising an annular member rotatable with said unit and provided with axially extending key means at least in part drivingly connecting the same with said operator member, said annular member affording a guide track in an outer axially facing side thereof concentric with the rotative axis of said structure, and an inner oppositely facing side for flush abutting engagement with said side surface of the wheel unit, at least one balance weight having a portion received by said track for arcuate adjustment relative to the latter and another portion projecting axially outwardly of said axial side of the annular member, and means to hold said weight in an annularly adjusted position in said track.

2. The structure of claim 1, in which there are two of said annular members, being similar to one another and presenting the respective tracks thereof on opposite axial sides of said wheel unit, and annular members clamping said unit therebetween to drivingly connect the latter with said operator member.

3. The structure of claim 2, in which said tracks are dove-tail shaped grooves formed in axially outwardly facing surfaces of the respective part members, the portions of the weights received therein being also of dove-tail shape to mate slidingly in the groove.

4. The structure of claim 3, in which the weights have set screw type means engageable with the respective annular members to hold the weights in adjusted positions.

5. The structure of claim 4, in which each of said grooves has at least one enlarged, outwardly facing access opening for the placement or removal of weights.

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