US2624158A - Buffing machine - Google Patents

Description

Jan. 6, 1953 F. E. HENDRlCKsoN 2,624,158

BUFFING MACHINE z IN VEN TOR.

F. E. HENDRICKSON BUFFI'NG MACHINE Jan. 6, 1953 2 SHEETS-SHEET 2 Filed 00t- 26. 1949 I N VEN TOR.

Patented Jan. 6, 1953 BUFFING MACHINE Soutlinllllgin,` Ill., assignor Frit'zj'E'. Hendrickson,

of one-fourth to' Bror Continuation of application Serial This application October 1949, Serialf,No..I23-,568

7 Claims)V (Cl. S12-141 l relates to polishing and builing machines and particularly to' such machines provided with a polishing belt running over a Work wheel. This application is a. continuation of my prior. co-pending application, for Polishing Machine, Ser. No. 680,455, led June 29, 1946, now abandoned.

One object of my invention is to provide a polishing machine comprising` a polishing belt, with improved means for starting up a newl belt. on ay partially resilient work Wheel.

Another object is to provide a polishing machine for supporting an abrasive belt on highly fiex'ible work wheels and on wheels that develop substantial belt-supporting stabilityv onlyA when running'.

Another object is to provide an improved ma-v chine for polishing irregularlyeshaped pieces.

Another object is to provide an improved abrasive belt machine for polishing manually sup'- ported pieces arid irregular pieces.

Another' object of my invention isV to provide a polishing machine comprising` a polishingb'elt,v with improved means for aligning the belt on the belt aligning pulleys.

Another object of my' invention is to provide a polishing machine having a polishing belt, with improved means for adjusting the work wheel so that thea front' side thereofA will. project proper amounts beyond the front surfaces ofV thev adjacent aligning pulleys.

Stili'another obj ect of" my invention yis to provide a polishing machine' comprising a polishing belt, the. belt operating over a work wheelwith manually''adji:r'stableA means for adjusting the po'-A sition of' the Work Wheel after ythe start ofthe' belt `and of the machine; I

Other objects of myinvention will eitherbe ape paren-t from a description of one My invention form of devicek embodying my invention or will be set out in f.

G. Giving, Elgin, III.

Fig. 8 is a sectional view therethrough taken on the line 8-8 of Fig. 5.

the cou-rse of suc-h description andl particularly setrforth vin the appended claims.

f In the drawings, Y Figure lis a View side elevation of a beltp'olishing machine embodying myA invention;

-Fi`g.f.2 isafront elevationall viewof the-machine shown in. Fig. 1-; Y

3- is a. sectional view, on an enlarged scale, on1the-line3-3 of Fig'. l; Figvlf isa vertical sectional-view therethrough;- takenon the-.lineA-ll of. Fig. 3; Y

Fig. 5 is a. horizontal sectional view taken. on the line. 55 of Fig/'7 Fig. (i is: a diagrammatic. view showing` different. positions, of the work wheel relative to the twoi aligning pulleys;v

Fig. 'l is a fragmentary.. sectional viewY taken. on` the line ,.'|-i|A of Fig;l 5 and,

Abrasive belts have been employed with rigid wheels, rubber faced wheels, and even sewed fabric Wheels, as for example in the so called backestand idler arrangement, but in such machines the work wheel was required to supev port and guide the belt and so was necessarily of a rm orrigid construction even though it might have a slightly-yielding, belt-contacting face;

In laccordance with my present invention I employ a belt-backing. work wheel, or back-up Wheel, of a highly flexible segmental construction that develops substantial belt-supporting, stability only while running. I have found that a belt on such a wheel yields4 to the pressure of Work and folds the belt over convex protuberances` and into holloWs of the work piece'.

Further, my present invention provides a machine, and method of operation thereof, for starting. up a belt on such a wheel wherein the flexible work wheel is required to supportA the belt only after it has attained a speed at which it develops suihcient belt-supporting stability.

Referring rst of all to Figs. l and 2 of the drawings, I have there illustrated, particularly in Fig. 1 of the drawings, a view in side elevation of a belt polishing machine designated generallyl in its entirety by While I have. shown a polishing machine comprising a pair' of polishing belts, I do' not desire toV be limited thereto', but' an'early device of' this kind built byrne was providedA with two polishing belts, sov that such assembly has been shown here purposes. The machine ll comprises a skeleton frame I3 consisting of vertically extending angle bar members l5 and |1 as well as horizontal lower angle bar members |'9 and upperv angle bar' members 2| together with upper and lower horizontal cross angle bar members 23. The assembled members |57, I1', i9, 2| and 23 are suitably s`e= cured together as bywelding so 4as to provide a skeleton frame, members I5 being longer than members l1.

An electric motor 25l of suitable size and speed.

is adapted to be mounted upon the lower angle bar members I9 and 23 andV is adapted to drive by a belt 21, a driving pulley 29 mounted onra shaft 3|. Shaft 3| is supported bybea'rings which are secured tothe upper angle bars 2|.

I provide furtherv an uppershaft 3l which is rotatably supported as byv a plurality of bearings 3Sy andA 4| which are suitably securedr against the front surface off the forward vertical barsA f5 at the upper end thereof. Polishing belts` is and-45- are adapted to operate over a pair of spaced aligning pulleys 41 and l5 onzthe-righta-handside of the frame as seen in Fig. 2' andover aligning for illustrative pulleys vI and 53 on the left-hand side of the frame. Pulleys 4'! and 5I are adapted to be suitably rotatably secured on shaft 3l. The lower belt aligning pulleys 49 and 53 are adapted to be supported on short shafts 55 and 5'I which are adapted to be rotatably supported by bearings 59 and 6I which are adapted to be specially mounted as will hereinafter appear.

I provide also a pair of work wheels 63 which are preferably of the kind disclosed and claimed in my co-pending application, S. N. 657,804, filed March 28, 1946, to which application reference may be made for the details of construction of the work wheels. Generally speaking, work wheel 63 is partially resilient and is of the self- Ventilating type. Each work wheel E3 is supported on a short shaft 65 which is supported as by a pair of ball bearings 6l and G9, these ball bearings being mouned in a hollow tubular member 1i. Member 'II is adapted to be rigidly supported on a square member 'I3 te which it may be Welded as by seams l5 of welding material. Member 'I3 is adapted to project through a hollow square member 'I'I which is supported by the front end of the horizontal bar 2 I. Member 'I3 is adapted to be adjusted longitudinally of its length in member 'Il' by a lever arm I9 and a pin 8l secured to member 'I3 and is adapted to be held in any fixed position relative to member 'Il' by a short shaft 83 having a hand wheel 85 thereon so that when by means of lever arm 'I9 work wheel 63 has been pushed outwardly as far as it is deemed Wise to push lthe same, rod 'I3 may be locked in a given position. Lever arm 'I9 is pivotally mounted at its lower end, on a plate 82 secured to bar 2 I, and a pivot pin 84. Each of the lower belt aligning pulleys 49 and 53, and their shafts 55 and 5l, are mounted on a substantially horizontal bar 81, the rear end of which is pivotally mounted on one of the rear vertical bars I'I, as by a pin B9. Lever arm 8'! is provided with a plurality of notches 9| intermediate its ends at its upper side and a short arm 93 is pivotally mounted on one of the upper bars 2 I and is provided with a laterally projecting stud or short shaft 95 so -that when arm 8l is moved down by a short rod 91 secured to arm 81, it may be locked in its adjusted position by short arm 93 engaging one of the notches 9 I. A Vertical guide bar 59 is secured tothe outside of one of the vertical bars I5 so that arm 6l may be held in desired operative position to provide the desired tension on the polishing belt.

Aligningpulleys 49 and 53 may be rotatably supported as by a pair of ball bearings II and |03 which are suitably secured in a hollow member |05 which is supported by a short bar I9? which may be made of substantially square shape in lateral section and be secured to member |05 as by Welding seams Hill.4 ported on a short bar member I I I as by a pin I I3, member I'l being adapted to extend substantially vertically. AThe lower end of member IIl'I has screw-threaded engagement with a short shaft I'I5 which is rotatably supported in one of the arms 8'! and is held therein by a bearing member I I'I. A compression spring H9 is located on shaft I I5 and abuts at one end against bearing I I'I while'its other end abuts against a washer IZI, which abuts against a small hand wheel I23 secured on shaft II5. It is obvious that turning movement of hand wheel I23 andof shaft I l5 in one direction or another will cause a change in the angle of shaft 55 and therefore of aligning wheel 49 relative to the bar 81. Y

.Extended tests on my part with machines of Arm Il is pivotally sup? this general type have shown the necessity of certain features hereinbefore described to which further reference will now be made. I have found, for instance, that when using a work wheel to support a polishing belt it is extremely difficult to start up a new belt on a belt polishing machine when using a partially resilient Work Wheel, if more than a slight amount of pressure is exerted by the polishing belt upon the work wheel before the belt has reached its proper operating peripheral speed. I have also found that when a new polishing belt has been started by means of the method hereinbefore described, the machine can be started and stopped any number of times for the lifetime of the belt without readjusting the pressure of the belt on the work wheel and that the belt Will remain aligned on the face of the Work wheel while running no matter how unbalanced the pressure of the work may be or from what angle the work piece to be polished may be applied to the belt supported by the work wheel.

Although the flexible work wheel E33 is incapable of properly guiding the belt or adequately sustaining much pressure, the aligning pulleys 4'! and 49 serve to keep the belt from running off in spite of the tendency of a Work piece to deflect the belt to one side Whenever it is applied off balance.

I have further found that in a belt-polishing machine of the type herein described, it is important that the extreme front end of the work Wheel project well beyond the front surfaces of the two adjacent alignment wheels, in order to provide room for manipulating the work piece while it is being polished and also to present a sufficiently large and resiliently cushioned surface for larger pieces of work.

I have particularly noticed that the machine will perform most satisfactorily when the in cluded angle formed by the two stretches of the polishing belt over the Work Wheel is between and and when the diameter of the work Wheel is approximately three to four times its Width. Reference may be had to Fig. 6 in regard to just What is meant by 90 and 150. The sec'- tion of the Work Wheel contacted by the belt will vary between 30 as a minimum and 90 as Aa maximum.

I may here again point out that as described in my hereinbefore mentioned co-pending application, the work wheel 63 is made of relatively soft material and is of a sectional, iiexible construction having, however, some inherent stability and is preferablyV of the ventilated type.` It is evident that when the machine lis not operating that there will be no centrifugal force actingv upon the individual sections ofA the work Wheel to tend to hold them extending substantially radially outwardly and to give them substantial belt-supporting stability. When starting up motor 25 and therefore the polishing belt 43, I have found that it is extremely difficult to properly start up a new belt on a belt polishing machine of the kind shown in the drawings if the work wheel has complete freedom from inherent stability as considerable pressure is exerted by the polishing belt upon the work wheel before the belt has reached its proper peripheral speed. For practical operation, I have found that the width of the periphery of the work wheel when running at full speed should be approximately the sameas the width of the polishing belt in order to be able to reach corners and bends in the workpiece to be polishedi and that this width should be from one-fourth to one-halfof the vdiameteiwofgthe work wheel. A narrow wheel tends to give the belt less support so that it is more easily pushed off by the unbalanced application of a work piece, whereas too wide a belt tends to double up in a longitudinal fold if a corner or point of the work piece is pressed deep into it. I have further found that when a new belt is installed and the machine has been adjusted at the initial run by means of the novel features hereinbefore described, the machine can be started and stopped any number of times for the lifetime of the belt and the belt will remain on the work wheel while running no matter how unbalanced the pressure may be that is applied by the work piece against the belt over the work wheel.

When a new belt has been installed around the l various pulleys 29, 41, 63 arm 93 disengaged from arm 81, the operating handle 19 is moved toward the work wheel just sufliciently to lift the pulley 49 from its lowermost position, thereby causing the polishing belt 43 to exert a very slight pressure on work wheel 63. The driving motor 25 is then started and the operating handle 19 is gradually moved so as to cause more pressure to be exerted by the work wheel against the polishing belt.

While the work wheel is thus gradually moved forward manually, the operator watches the alignment of the polishing belt upon the work wheel from the .front of the machine as seen in Fig. 2. If any tendency to misalignment is observed, the adjusting wheel |23 is turned in the proper direction to bring the polishing belt in perfect alignment with the Work wheel. As soon as such alignment has been effected, the operating handle 19 is moved all the way forwardly and the work wheel is locked in this position by means of the locking hand wheel 85. At this stage the only tension on the polishing belt is caused by the gravity of pulley 49 and lever arm 81, but this tension is not sufiicient for satisfactory operation. Manual pressure is then exerted downwardly on handle 91 on lever arm 81 and at the same time locking lever 93 is pushed downward against the teeth 9| provided in the upper edge of lever arm 81. Considerable pressure can be obtained by this method and an experienced operator will soon determine just what is the optimum pressure. I provide a biased take-up, or automatic control of the tension of the belt during the starting of the machine, the truing up of the alignment, and the setting of the work wheel; and I provide also means for locking the takeup wheel in an adjusted position during the use of the machine.

Various modifications may be made in the device embodying my invention without departing from the spirit and scope thereof and all such modiiications coming clearly within the scope of the appended claims shall be considered as covered thereby.

I claim: j

1. In combination in a polishing machine, a plurality of pulleys for a polishing belt comprising two aligning wheels and a work wheel therebetween, said work wheel comprising a hub and a plurality of separate segmental outward-extending sections of flexible material supported thereon, the whole wheel being so flexible that it develops a substantial part of its belt-supporting stability by centrifugal-force, a movable support for said work wheel permitting movement thereof transverse the tangent between said aligning wheels sufficient to move said work wheel from a position in which it barely touches a and 49, and with lever belt on said aligning wheels to a position in which from 30 to 90 angular degrees of the periphery of an uncompressed work wheel engages said belt, another of said plurality of pulleys having a movable support movable for tightening a belt, and means for locking the movable supports of said work wheel and belt-tightening pulley.

2. The combination of the immediately preceding claim wherein said belt-tightening pulley includes means for biasing it in a belt-tightening direction.

3. A polishing machine as set forth in claim 1 in which the diameter of the work wheel is from two to four times the Width of its face.

4. The combination of claim 1 wherein there is included a belt on said pulleys having a width substantially equal to the width of the work wheel.

5. In a polishing machine including a, pulley stand, the combination with a driving pulley for an abrasive belt and a support for the driving pulley, of, a supporting structure forward of the drive pulley, two forwardly-projecting pulleysupporting brackets thereon for supporting two aligning pulleys one substantially above the other, aligning pulleys on said brackets in position to receive and guide an abrasive belt, means for adjusting one of said brackets about an axis at an angle to the axes of said three pulleys for changing the angularity of its pulley, means for adjusting one of said brackets in a direction to aifect the tension of a belt on said pulleys, a work wheel for backing up said belt mounted on said supporting structure between said two aligning pulleys, and means for adjusting the work wheel against the belt for deflecting it from a straight path between said two aligning pulleys.

6. The combination of claim 5 wherein the one of said brackets is adjustable for imposing both said adjustments on the wheel thereon.

7. The method of backing a polishing belt in a polishing machine wherein the belt travels over supporting pulleys and a soft backing pulley having belt supporting stability only when rotated, which method comprises starting the belt running over the pulleys but in only light contact with the backing pulley whereby to start the backing pulley rotating, then moving the backing pulley into iirmer contact with the belt to increase the speed of rotation of the backing pulley and supporting the belt under working tension against the belt supporting face of the soft backing pulley when it is rotating substantially at the surface speed of the belt.

FRITZ E. HENDRICKSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 314,906 Young Mar. 31, 1885 1,045,945 Carney Dec. 3, 1912 1,744,807 Schulte Jan. 28, 1930 1,754,292 Warren Apr. 15, 1930 2,280,399 Garling Apr. 21, 1942 2,334,960 Roth et al Nov. 23, 1943 2,376,847 Glike May 22, 1945 2,402,131 Fowler June 18, 1946 2,415,947 Hendrickson Feb. 18, 1947 2,431,795 Elmes Dec. 2, 1947 2,469,735 Lindsay et al May 10, 1949

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