US2215210A - Abrasive belt - Google Patents

Description

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Sapt. 17, 1940.

INVENTOR. ERIC P. DAH LSTROM y ATTQRNEY;

Patentedept lZ, i I I s UN1.TE.D`TSTATES PATENT OFFICE e r B AS LI* Eric Pi Niagara Falls, assignor to The Carborudum Company, Niagara Falls, MY.,aco-porationotDelaware f Application December '9', 1938', Serial No. 244, 795

' i jioain. (c.5 1's8) This invention' relates to abrasive belts "and of two straight lines 5 and 6,vwhich are of the. tothe method of 'naking'the same. 'More parsame length. v 4 ticularly', it' relates 'to joints or splices'in abrasive- The portion' o of abrasive coated flexible mabelts and to the method of making said 'joints terial to be joined tothe salient portion described' '5 or splice's. j i aboveis -illustrated in Figure 2, and, as shown r One object of the invention is to provide abrathere,` is formed with a boundary H that is resive belts having imp'roved joints or splices. Anentrant and complernentary to the salient edge other object-is 'to' provide ta .methodofu making '2'described above. In this piece, the abrasive V improved'joints or splices in abrasive belts., Other grain coating extends to the edge or. boundary objectswill become apparent from' the following ll of the reentrant edge. v a v disclosure.` r v I' r i g The abrasive-free area 3 of thesalient 2 may In order that a full understanding of the inbe vforme'd in various ways, but it has been found vention may be; had, reference is made to the to be convenient to remove the abrasive grains appended drawing, in which from a fully coated sheet, that is, 'ajsheet in Figure 1 is a plan 1View of; a portion of coated which the abrasive grain coating extends' fronl` abra'sive material designed for use inonewmodi edge to edge, by the careful application of a' fication of: the presentinvention; rotating abrasive wheel tothe part of the sheet -Figure 2 is a plan viewofa portion 'of abrasive thatis to be reed of abrasive grains. y coated material adapted to adjoin the portion careful application of a rotating` abrasive illustrated in Flgure 1; i i `wheel to the'abrasive coated sheet will remove 2 Figurea isa lan View of a portion oi' a' belt r the abrasivegrains and most or substantially all e embodying one. modification( of the" present inof' the a'dhesive without damagin'g theflexible yention in which the portions separately iliusbackingmaterial; i v trate'd in Figures 1 and"2 are shown joined; The abrasive-free area 3 at the salientedge Figure 4 is an enlargedcross-sectional'view, of theapiece l ltiirtbendprot idedkthe uncoated 25 along the:line IV.- IV of Figure 3, 01 a portionof area is coa a hes ve o the desired 4 a belt ernbodyingthe modification iliustrated in character and the piece o with the reentrant F'igure ifter, the sections shown' in'` Figures 1 arg i complementry C(legge is placted on -tip ofathe and ve been placed in juxtaposition but a rasive-freean a' esive coa ed por on so beiore the two sections' have been obinpresed that the abrasive boundary 4 of the salient piece 30 flrmly togsether to iorn aclse strcnfjoint; b I anid'the bunday lltcf thtehreetranpiec ;g

Figure ,is a'p'an v ew o 'a por ion of a elt are' n regis er an so a e e ges an erbodying another modificationaof the present line up in a straight line on one side and the invention; r ees zzdand 2? lie-pdiatraigit line o'n the r '35 Flgure 6 is a plan view of a portion of a belt o er si e, as ilus ra e e i The overembod'ying still another modification oi the preslapped portions of the two-pieces are then pressed ent invention; and' e v a ;together and held so that they cannot move while Figure 7 isa plan view of'a portion of a`be1t he d v iS settingv 'embodyingstill another modification'ot the presv Figur& Shows in eleYation an'enlarged w m t :mesazh tiul'ii i In making a bel according to e mo fica ion V v ot (the present invention illustrated in Figures the Place 5 Show? b in i e contact 2, a andt'ga' piece ofabrasive coated flexible With thbackmg the piece These back' material I of sitable Size ;prevpred the ings may be of any su table flexible material, such e e a as paper, cloth, fibre, metal or other fiexible Joning operation by Iorminga salient edge 2 e d f a d mg sheet materal 01 of any suitable combination of p m s 3 r e a two or more of such materialsin laminated form. swe miting in e W? yv 9 t #went edge- In Figure &thejont is-shown'after the two end v Als umtmtd' theahmsve'ree F 3:15 mund' portions of'thebelt have been. placed in juxtaed e e 2 of h Meriton e d n position but beforethe final pressure is put on 0 by h edge 7 O h abrasivey m u i h: 15 them to force them into more intimateirelation- :i ii:: zzszuzzeagii e e gure 's ows a p an view of a modified belt salient illustrsted in Figures 1, 3 and 4 is tormed joint made according to the present inventio', by the inter-section, at the center line of the belt, where the salient end portion is angular, but the 55 the crown pulleys, and sometimes serves to deter the belt from a tendency to track sideways ofl' the pulleys.

Figura 6 shows a plan view of a further modification of the present invention where the apex of the salient portion of the belt end is notsharp and angular but where the apex portion has been rounded ofi to remove the angular intersection portion of the salient. This 'shape can be used to advantage where the belt formed passes over certain types of pulley shapes.' V

Figure 7 shows a plan view of a still ifurther modification of the present invention where the salient end portion of the belt is in the shape of a semicircle. In this modification a straight line cannot be drawn which will fall on the line of junctl'on of the belt ends, but will always merely cross the joint, since' the direction of the joint` is constantly changing. This efiect is obtained while still retaining all the advantages of a salient joint and the Construction of the present "invention( r The joints shown in Figures 5, 6 a'nd'7 are all likewise formed in the manner set forth in' connection with the belt portions shown in-Figures 1 to 4. i

`Belts possessing joints or splices made according to the present invention possess numerous advantagesover belts jointed by the methods heretofore used. Heretofore belt joints have either been made so that the line of joning between two adjacent belt ends laid either perpendicularto the line of movement of the belt or in a single direction oblique thereto. Slight variations in this procedure have been to give such joints an i irregularity by curving or otherwise zig-zag'ging or serrating the line 'of joining in order to strengthen the joint. However, by the present invention of a joint wherein the end of one belt section has a contour such that the central portion of the end boundary is protruding or salient with respect to the portions of the end boundary at either side thereto, and the second or adjoining section has a complementary re-entrant shaped end, a belt is obtained of improved running characteristics. By the use of such belt joints the belt is given what might be termed an automaticoscillating effect. As the belt joint of the present invention passes over the crown pulley there is a tendency to draw toward the center. Then as the splice or joint leaves the crown, it may tend to track one way or another, depending upon the alignment of the remaining pulleys; but as the splice again goes over the' crown, it .again tends to center itself. This efi'ect is of particular value in the use of wide belts. Minor i tendencies to track to one side or the other can often be counteracted by proper alignmentof the pulleys but in cases where it is impossible to obtain suitable' adjustment of the pulleys to cause the belt to track satisfactorily it is' found that the belt splice of the present invention serves to give a centering of the belt by the above-explained 2,215,2o 4 I, I j automatic oscillating action in a highly s atis factory way.

Furthermore, by still retaining an oblique direction of the joint with respect to the movement of the belt the belt is caused to run smoothly and with little or no vibration since the joint is grad ually presented under the work instead of suddenly appearing.

A further decided advantage of thepresent invention is its Simplicity of construction of .the belt joint or splices. Previous efforts to obtain a belt having similar Operating advantages have led to `cumbersome and time-wasting methods of jointure. Resort has been had to constructions whereby the end portion need be slotted for inthe use of complicated joint structures involving I sertion of the abutting end section, or tongue or i tab arrangements have beenused, which tabs or tongues have to be interlocked or fitted together. The present' invention avoids these manufacturing disadvantages in a very simple but ingenious V way by formingthe two 'end sections into a'salient and' a corresponding complementary re entrant shaped end section, sklving the abrasive from .theend edge portion of the salient section and joining the two in the manner previously described in detail. The salient section is much easier to clear of abrasivefrom the portion `borderingthe end without injury to the adjacent abrasive' areas than is removal of abrasive fromthe re-entrant portion. Therefore in the making of belts there is a decided saving of time and a lower number of rejections of belts due to defects in the joint;

A further, advantage of the belt joint of the present invention resides'inthe fact that when in Operating the belt is run in a direction so that the joint approaches the* work with the apex' foremost, in other words, the belts as' illustrated'in.

formedfrom a single abrasive strip with the ends jointed, it is particularly well adapted to forming extra wide 'belts from a number of pieces of abrasivematerial where thewidth; of the belt'is greater than the width of the original abr'asive strips, thus necessitating the use of numerous pieces of abrasive sheet material `joined in several places.

Other advantages are readily discerniblefupon consideration of the invention herein set forth.

Having described my invention in its preferred embodiment I do notwish to limit myself other .than by the scope of the appended claim.

I claim: i i i p In anabrasive belt, a joint between adjoin'ing portions which comprises a plurality of layers'in juxtaposition and adhesively united,`the under layervbeing bounded at the juncture by a salient edge and being free of abrasive material in the area bounded by said salient edge and a'line of substantially the same contourbut spaced apart there'from, the upper layer being bounded' at the juncture by an edge" which is re-entrant and compl'ementary to the salient edge of the lower layer. ERICP, DAHLSTROM.

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