AU2006232003B2 - Cut-off wheel - Google Patents

Abstract

The invention relates to an abrasive cutoff wheel which comprises a central disk (2) and a plurality of abrasive segments (4) which subtend between themselves a straight bonding line (10) that slants inward along a predetermined disk direction of rotation (12) toward the wheel center of rotation 14, deviating from a tangent line. Seen in wheel sideview, the radially outer surface (18) of each abrasive segment (4) preferably also is straight and slants inward along the wheel direction of rotation (12) toward the wheel center of rotation (14), deviating from a tangent line.

Description

build. material ..particular concrete, .bricks, roof tls, and to cu t .pr . . . . .. 5 natural stone, A reference herein to a patent documnernt or other matter which is given as prior art i. rot to be taken as an admission that that document or matter was, in Austraa, .known or that the information it contains was. .art of the comrnon general knowledge as at the priority date of any &f the clafosn 10 An abrasive cutoff whtei of this kind is; disclosed in th'e German patentdocument bS 44 24 093 02 It comprises both a central disk: an d segments.. The segments are undetachably .affixed by .lWer welding to the central disk c. .rfern.e v.hich is .otinuous &r whh- ub-dvddy eraui-fer.riti....... . .earn.es into -projecting tbS, The -le connecting the segments and the--....... - -5. outer contour of the central diak runs tangentialyto the central disk origin or is.... constituted by: two correspondijng tangential. straight I oes for eatch segmerit.... saiPd two lines subdending, in roof-like manner, betweeri then an Arngle of less.... ...... The objective of the present invern ion s abrasive cutff-wheel 20 .improvement . . . . . . . . Ac.otding to the present irivdntion, there is provided-An abrasive cutoff.... wheel carprising a central disk and a plurality of -abrsive segrnents distributed 5iong a circuriferance of te central disk on the srne anmber of disk juction f.ces hat .ar strah :as ... -in whe. . side view and that....... 25 cornp-rise each ~eentjntion ftace which is undetachably affixed to only.... - -- one ot the disk j rnction faces, wharen the abrasive {utof oth vheee is driven into -.-.. .... a predetermined direction of rotation in that each sk junction tace. and the....... segment junction: tace afixed to it wher seenr wheel sideview st-nd .. a straight bonding lin which , in the predetermined direction of rotation slopes vasinvard toward the wheel center- of rotation, deviating from a tangent line, wherein thradilly onter suriae of each abrasive segment .is .straight as. seen....... in wheel sidevw and define a straight surface kind ib:ch san iward in thG...e. dei -of the wh4el center of rotation, deviating from a: tangent: line; and...... . ~ ~ ~ ~ I .4 .M~ .

ihereih the surface line and the bonding line of the particular abrasive *ye~jnerUt are rnutualy paallet The invention can advantageously offer improved -distribution of forces at the bonding loe betWen the abrasive segrtents and the central disk, 5 allowing hi-gher loading on the. abrasive cutoff wheel. The present !nventilon can further advantageously convert a substantial portion of the shearing forces 2 arising in the dry severing method into compressive forces that are applied in the bonding line between the abrasive segments and the central disk. In one preferred embodiment of the present invention, the radially outer surface of each abrasive segment is straight when seen in wheel side view 5 and this outer surface of each segment defines a surface line sloping inward in the direction of disk rotation toward the center of the wheel, deviating from a tangent line. As a result, when the abrasive cutoff wheel is used for the first time, only a minute part of each abrasive cutoff segment makes contact with the work piece to be cut, and thereby allows automatically honing the abrasive 10 segments during first time use. The abrasive segments can be composed of, at least in their top zones, an imbedding material containing imbedded diamond elements illustratively sintered into said imbedding material. Before an abrasive cutoff wheel is used for the first time, the diamond elements do not protrude from the imbedding 15 material, so that the abrasive cutoff wheel must be honed before or by means of first use to assure the diamond elements shall project above the imbedding material. In another preferred embodiment of the present invention, the surface line and the bonding line of the particular abrasive segment are always 20 mutually parallel. In a further preferred embodiment of the present invention, the central disk is fitted with one circumferential notch between all adjoining disk junction faces. In this manner material abraded from a workpiece more easily escapes from the notch formed in the workpiece. 25 The present invention is elucidated below by means of a preferred embodiment and in relation to the appended drawing. Fig. 1 is a sector-like cutaway of a sideview of an abrasive cutoff wheel of the invention. The abrasive cutoff wheel of the invention shown in Fig. 1 substantially 30 includes a circular central disk 2 and a plurality of abrasive segments 4. The abrasive segments 4 are distributed preferably symmetrically along the full outer circumference of the central disk 2 on the same plurality of straight (as seen in wheel side-view) disk junction faces 6 and each segment is fitted with its own segment junction face 8 that is undetachably joined, for instance by P:UserfBeliria\BEH\11515\B11515 SPECI doc 3 brazing, welding or laser processing, to one of the disk junction faces 6. The central disk 2 preferably is made of steel. The abrasive cutoff wheel of the invention does its cutoff work in a predetermined direction of rotation 12. 5 Each disk junction face 6 and the segment junction face 8 joined to it determine between them a straight bonding line 10 (as seen in wheel sideview), this bonding line sloping inward along the predetermined direction of wheel rotation 12, relative to wheel center of rotation 14, that is, deviating from a line tangent to the wheel center of rotation. A conceptual radial line from the 10 wheel center of rotation 14 to the center (in sideview) of a disk junction face 6 subtends an angle with said surface 6 that deviates from 900. The radially outer surface 18 of each abrasive segment 4 is straight when seen in wheel sideview and defines a straight surface line 20 which as seen in wheel sideview slants in the direction of rotation of the wheel toward 15 the wheel center of rotation 14, deviating from a tangent line. The surface line 20 and the bonding line 10 of the particular abrasive segment 4 preferably are mutually parallel. Between every two mutually adjacent disk junction faces 6, the central disk 2 is fitted with a circumferential notch 22 respectively 24. 20 In the preferred embodiment shown in Fig. 1, the circumferential notches 22 and 24 differ in depth, a deeper circumferential notch 24 and a shallower circumferential notch 22 alternating along the circumference. The configuration of circumferential notches of different depths lowers the danger of cracks in the central disk. 25 A spacer gap 26 is subtended in all embodiment modes of the invention between the circumferentially sequential abrasive segments 4 to facilitate eliminating ground material when grinding the workpiece. The bonding line 10 and a radial line 30 subtend an angle deviating from 90* at least at the longitudinal center point of the disk junction face 6, 30 preferably however also at any other point along the length of the segment junction face 8. As a result the angle a situated in the predetermined wheel direction of rotation 12 in front of the radial line 30 is less than 90* and the angle @ situated behind is larger than 900. P kUseBelinda\BEI\B11515\811515 SPECI doc 4 The circumferential notches 22 and 24 preferably are slots open at the outer central disk circumference. Said notches subtend a defined angle y preferably larger than 900 with the connecting line 10, respectively the disk junction surface 6, preceding them in the wheel's direction of rotation 12. 5 The invention described herein is susceptible to variations, modifications and/or additions other than those specifically described and it is to be understood that the invention includes all such variations, modifications and/or additions which fall within the spirit and scope of the above description. PAUsefBelnda\BEH\11515\811515 SPECI doc

Claims (2)

1. 3. Abrasive -cutoff wheel as clmned In claim 2, vihereir- the deiths tfothe circumferential notches are different, a deeper circumferential notch and a 26 Shallower circumferential noth alternating in the wheel circumferential direction,
2. 4. An abrasive cutpff wheol according to the embodiment substantidAy as heroin draschbed and illustrated. 30