US2948090A - Abrasive wheels - Google Patents

Description

Aug. 9, 1960 C. KLINGSPOR ABRASIVE WHEELS Filed Jan. 13, 1959 Figa @Milou/V llnited States Patent.

ABRASIVE WHEELS Carl Klingspor, Waldstrahe `13a, Siegen, Westphalia, Germany Filed Jan. 13, 1959, Ser. No. 786,588 lClaims priority, application Austria Jan. 15, 1958 Claims. (Cl. 51-193.5)

This invention relates 'to abrasive wheels formed by rotary abrasive members comprising abrasive flaps of abrasive linen or a similar flexible material, which are unilaterally inserted in a .carrying ring with freedom of oscillation. Such members are known for grinding and, where a suitable abrasive is selected, also for polishing work. These abrasive members, however, have the disadvantage that when constructed in large widths by arranging several such abrasive ap carrying rings side by side they produce grinding marks at the joints of the several rings. On the other hand, it is not possible to use the abrasive tiaps themselves in the desired width and it has been found that abrasive flaps having a width in excess of approximately 300 mm. give rise to various difficulties.

The present invention shows how abrasive wheels of any desired working width can be obtained by arranging several abrasive flap carrying rings side by side. rThis assembly may be effected by the user himself. In order to achieve this object the invention proposes a special construction of the ring which carries the abrasive flaps.

According to the invention 4the abrasive wheel is characterized in that the abrasive liaps are arranged on each carrying ring in the form of a helix, the length of which may be between a fraction of a full turn and several turns, and each carrying ring is bounded at its ends by helical surfaces of appropriate length. For instance, the carrying ring may have a circumferential length of 360 and form an offset or recess whose depth corresponds to the lead of the helix in order to enable the assembly of a plurality of such rings having mating recesses to form an abrasive wheel of increased working width.

The invention will be explained more fully with reference to the accompanying diagrammatic drawings wherein:

Fig. 1 is a sectional view showing an abrasive member according to the invention, with closed boundary faces which extend in accordance with helices at the ends to form the above-mentioned recess.

Fig. 2 is an end view of the structure of Fig. l.

Fig. 3 is a partly sectional view showing diagrammatically an abrasive wheel having aps and rings forming several (approximately tive) helical turns.

Fig. 4 is another partly sectional view showing how individual abrasive rings as shown in Figs. l, 2 can be af- Xed to a grinding spindle.

Fig. 1 and 2 show an abrasive member which comprises a helical carrying ring 1, the ends of which are bounded by helical surfaces 2. These surfaces have the lead a which is less than the width of the ring 1 so that two steps or recesses 2a and two projections 2b are formed. The carrying ring 1 preferably consists of a plastic substance, but it may also consist of a metal with low melting point or another suitable material; the several substantially radial abrasive flaps 4 are embedded in this material. 'Ihese aps consist of abrasive linen of appropriate grain size, abrasive paper or the like. The aps being iden- ICC tical in form, their side edges 4a lie also on helical surfaces, whereas their end edges 4b lie on a cylinder. It will be appreciated that several abrasive members having the form apparent from Figs. 1, 2 may be closely aligned adjacent to each other-on a shaft, the projections 2b of one carrying ring being received in the recesses 2a of the adjacent retainer ring. It is'also apparent that such an abrasive wheelor screw composed of several abrasive members is suitable for the machining of surfaces having a corresponding Width without forming grinding marks because the joints between the individual rings formed between the abrasive iiaps follow a (stepped) helix.

IInstead of combining several loose rings as shown in Figs. 1, -2 to form a composite abrasive wheel the circumferential length of the rings, which is 360 in the example of Fig. l, may be increased -to a multiple of this value to provide a helix having several turns by adhesively connecting `a plurality of rings as shown in Fig. 1 to form a screw. An example of this type is illustrated in Fig. 3. The resulting helix is carried by a support 10 having supporting flanges 10a which extend in accordance with an appropriate helical surface, and is forced against these flanges by a second support 11 having appropriate supporting anges 11a. The retaining means or supports 10, 11 may be forced against each other in any suitable way or may be affixed to the grinding spindle 12 by means of a nut and lock nut (not shown).

Fig. 4 shows another fixation of the several abrasive rings -to a grinding spindle 13. Each group of abrasive flaps 4 forming part of an abrasive members has at its ends a closed annular groove formed by the recesses 14, see also Figs. l, 2 and 3. Gripping or retaining rings 15 are provided, each of which consists of a hollow cylindrical hub 15a having a helical retaining rib whose ange 15b tits into the grooves formed by recesses 14 in the flaps 4 of two adjacent abrasive members so that it can be screwed into the same. The configuration of these retaining ribs and of their flanges 15b is diagrammatical- 1y shown in dash lines in Fig. 4. The abrasive rings 1 may be screwed onto the gripping or retaining rings 15 in such a manner that each abrasive ring 1 has a gripping or retaining ring 15 associated therewith, the latter rings being axially aligned on the grinding spindle 13 and being axially forced together on the same by suitable means. In the illustrative embodiment shown it would be necessary, therefore, to force the gripping rings 15 by a nut (not shown), which is carried by the screw thread 13a, against the collar 13b of the shaft 13. Resilient inserts may be provided between the end faces of adjacent gripping and retaining rings 15 or a free space may be left between said end faces so that the abrasive rings are more or less compressed in the axial direction. It is lthe object of all these measures to obtain a firm fixation of the annular or disclike abrasive members to a grinding spindle to ensure a reliable retention of the abrasive members on the spindle even at high speeds.

Appropriate molds are used in the manufacture of the present abrasive members. The abrasive flaps are inserted and xed in said molds, whereafter the carrying ring 1 is formed by casting so that the inner edges of the abrasive aps are embedded in the matrix forming the ring 1.

What is claimed is:

1. An abrasive wheel comprising, inl combination: a rotary spindle; a plurality of abrasive members mounted on the spindle, each member comprising a continuous helical ring `of uniform Width bounded by a pair of helical end surfaces whose lead is less than the Width of the ring whereby a recess and a projection is formed at each end of the ring, and a plurality of similar substantially radially arranged abrasive aps each having an inner end embedded in the material of the the ring, the

iaps of each abrasive member forming a helix surrounding the respective ring and the aps of adjacent abrasive members forming a continuous multi-turn helix about said spindle; and means `for retaining the rings against rotation with respect-to said spindle.

2. An labrasive wheel as setfforth in claim 1, wherein said rings are of .pl-astic.

3. .An abrasive vWheel as set forth in claim 1, wherein the projections `of each ring extend into the recesses of adjacent rings and said retaining means comprises a pair of flanged supports non-rotatably ixed to -the spindle and each bearing against an outermost ring for pressing .the adjacent rings toward each other.

4. An `abrasive Wheel as set forth in claim l, wherein said retaining means comprises an annular gripping rnernber for each ring, each gripping member having a hub received in the respective rin-g and non-rotatably surrounding said spindle, and a helical rib connected to the hub and extending 'between the end surfaces'of adjacent rings for holding the rings against rotation with respect `to the spindle.

5. An abrasivel wheel as s'et forth in claim 4, wherein each flap has a pair of side edges each formed with a recess, said last mentioned recesses forming two helical grooves in the ilaps of each abrasive member, and each gripping member yfurther comprising a helical iiange fixed to the rib and extending into the recesses of adjacent flaps.

References Cited in the file of this patent UNITED STATES PATENTS 539,464 Whitaker May 21, 1895 1,628,352 Bonazzi May 10, 1927 2,651,894 Leggett Sept. l5, 1953 2,678,523 Leggett May 18, 1954 2,802,315 Block Aug. 13, 1957

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