US1892434A - Segmental grinding wheel - Google Patents

Description

Dec. 27, 1932. T. LARSSON SEGMENTAL GRINDING WHEEL Filed June 12, 1926 Witneses Uhure fiarsson Patented Dec. 27, 1932 UNITED STATES THURE LARSSON, OF WORCESTER, MASSACHUSETTS, ASSIGNOR TO NORTON COMPANY, OF WORCESTER, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS SEGMENTAL GRINDING WHEEL Application filed June 12,

This invention relates to grinding wheels and more particularly to a chuck for holding abrasive segments for use on a surface grindin machine.

It has been common to make surface grinding wheels in the form of asolid ring of abrasive material and fasten this ring to a metallic chuck by means of sulphur or other suitable cementing material. Such rings are expensive to make and are frequently broken during the process of manufacture as well as during use.

In a chuck for a segmental surface grinding wheel, it is essential that the abrasive sega ments be held rigidly in the chuck at a point as near as possible to the operative grinding surfaces to prevent Vibration and breakage of the segments. In such constructions it is necessary, therefore to adjust the position of the segments frequently as they become worn. In former constructions, the segments have not been properly supported in the chuck and it has been difficult to adjust theirposltion relative to thechuck. a

It is an object of the invention to overcome these difficulties and to provide a practical fastening device to hold abrasive segments in place on a driving head of a machine in various positions ofadjustment acplace upon the segments.

- It is another object of the invention to provide a chuck for holding abrasive segments rigidly so that the grinding surfaces will be maintained aligned during grinding and may be easily and readily repositioned when worn.

It is a further object of the invention to provide abrasive segments so constructed that they might be arranged and mounted upon a supporting member in such a manner as to be readily and conveniently repositioned when Worn relative to the supporting member. I

In accordance with theinvention-a grinding wheel is provided composed of a plurality of abrasive segments specially shaped for mounting on a suitable supporting member, such as a ring. -The segments are adjustably held on. the supporting member so that they may be moved when worn to extend beyond which,

cording to the degree of wear which has taken 1926. Serial No. 115,629:

an edge of the supporting member to present a fiat grinding surface. An adjustable stop is provided which is arranged to engage the end of each segment opposite the grinding surface to locate their positions and hold them rigidly in alignment during grinding. The segments'may be held against the supporting member conveniently by alternately fixed and adjustable clamping devices, preferably, of wedge shape and positioned be tween the segments.

The invention will be more clearly understood from the following description in conjunction with the accompanying drawing; in

. v Fig. 1 is an end elevation of a segmental abrasive wheel;

Fig. 2 is a. sectional view taken on the lin 22 of Fig.1; I x r Fig. 3 is a sectional View taken on the line 33 of Fig. 2 showing the abrasive segments in one position relative to the, supporting member;

Fig. 4 is a similar sectional view showing the abrasive segments advanced to another position relative to the supporting member; Fig. 5 is a similar sectional view showing the abrasive blocks advanced toa third holding position; 3

Fig. 6 is a plan View of a suitable form of adjustable stop which is adapted to engage the ends of each abrasive segment opposite the grinding surface; and I .Fig. 7 is a perspective view of the fixed clamping device embodying means for hold "ing the adjustablestop.-

In the drawing, I have illustrated a segmental surface grinding wheel embodying and illustrating the invention. This wheel comprises a supporting member 10, such as a ring, adapted to be secured to any suitable rotatable driving head 11 shown in dotted lines in Figs. 3, 4 or 5 which is secured to or integral with any of the well known grinding wheel spindle constructions in any suitable manner, such for example as by screws 12. A plurality of abrasive segments 14 are suitably shaped to engage a surface of the supporting member, and for this urpose lands 15, preferably, are provided. he end 100 of each abrasive segment is provided with a flat grinding surface 20, and when the segments are in operative position they extent asubstantial distance beyond one edge of the member 10.

The segments 14 are adjustably held against a surface of the supporting member 10 in any suitable manner, but as illustrated a clamping device 16, preferably of wedge shape, is provided integral with or secured to the supporting member 10 by means of screws 17 and is adapted to engage one side of each adjacent segment. The other side of each segment is engaged by an adjustable clamping device 18, preferably of wedge shape, which is connected to the supporting member 10 by means of an adjusting screw 19. The abrasive segments 14 are provided with side faces adapted to engage the clamping devices, and in accordance with the referred construction have side clamping ace portions which converge in an outward direction. The spaced projecting lands and the bevelled clamping surfaces engaged by the clamping blocks 18 are located opposite each other so that the clamping pressure will be transmittedradially inwardly and directly from the clamping blocks to the convex cylindrical supporting surface of the ring 10. It will also be observed that the clamping blocks lie wholly between the ends of the segments and so permit the wheel to grind up to a shoulder.

In order to secure rigidity of the wheel during grinding the end surface of each abraring 24 is adapted to engage the end surface is engaged and supported by an adjustable stop operatively associated with the supporting member 10. A suitable arrangement for this purpose may include a ring 24., or other suitable device, provided with a plurality of tongues 25 adapted to engage the aligned holding surfaces 26, or the surfaces 27 or 28, each of which locates parallel Planes (see Figs. 3, 4, 5 and 7 These surfaces are preferably integral with or otherwise rigidly secured to the supporting member 10, and are arranged to face in the same direction as the grinding surface 20. An extension 30 on the ring 24 is adapted to engage the end surface of each abrasive segment opposite the flat grinding surface.

The tongues 25 on the adjustable stop, or ring 24, are spaced so as to leave openings 31 therebetween such that the ring 24* may be moved about the supporting member 10 to engage the holding surfaces 26 or may be disengaged therefrom and moved in the direction of an elementof the supporting member 10 to another parallel plane, such as that located by the aligned surfaces 27 or 28, the openings 31 permitting the axial movement of the ring pastthe projections 29. The

projections 29 may be formed'integral with the supporting member 10, or as shown in the drawing may be separably mountable thereupon so as to rest against a shoulder 32 on the member 10 and he held securely thereupon by screws 33; As: shown in the drawing the projections 29 are represented as an integral part of the clamping device 16 but it is obvious that this is not necessary and that both the clamping devices 16 and the projections 29 may be formed as separate and entirely independent parts.

7 When the abrasive segments 14 are properly assembled for grinding upon the supporting member 10 they extend a substantial distance beyond one edge of the supporting member 10, as clearly indicated in any one of Figs. 3,4 or 5. Fig. 3 shows the se ments assembled in the chuck in their initial position and held against the supporting member 10 by the clamping devices 16 and 18. During use the the abrasive segments graduall wear until the fiat grinding surface is rought close to the edge of the supporting member 10. It is then necessary to reposition the abrasive segments so that they extend a substantial distance beyond the supporting member 10 to present an operative fiat grinding surface.

This may be done by loosening the screws I 19 to release the clamping devices 18 which permits the abrasive segments 14 to .be moved in the direction of an element of the supporting member 10 to position them appropriately beyond the edge of the member 10. The ring 24 is then turned to disengage the tongues and the holding surfaces 26 and bring the openings 31 over the projections 29. The ring 24 is then moved along an element of the member 10 until the tongues 25 are brought into the plane located by the aligned holding surfaces 27 and is then turned until the tongues 25 are brought into engagement with the surfaces 27. The abrasive segments 14 are then moved to bring that end surface of each which is opposite the fiat grinding surface into engagement with the extension of the ring 24. The screws 19 are tightened so as to adjust the clamping devices 18 against the abrasive segments and hold the latter against the supporting member 10 in the position indicated in Fig. 4. Likewise, when the abrasive segments become worn again they may .be moved from the position indicated in Fig.4 to'that indicated in Fig. 5. By the provisions of'the invention a segmental surface grinding wheel may be constructed in which the abrasive segments are held in a rigid and satisfactory relation, and yet which may be conveniently and readily adjusted to accurately reposition the segments as desired when worn and hold them in an equally rigid manner.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is;

1. A grinding wheel comprising a chuck having a substantially circular supporting surface, a pluralit of abrasive segments mounted as an annu us against said surface in an adjusted position and extending beyond one edge thereof to present a substantially continuous fiat grinding surface, clamping devices on the chuck in engagement with the segments which are separately adjustable to press the segments against said supporting surface, a single stop mounted on and adjustable relative to the chuck, and means cooperating therewith which serves to locate the "stop in one of several predetermined positions, andthereby align the grinding faces of the segments in each adjusted position.

2. A grinding wheelcomprising a chuck,

having an outer cylindrical supporting sur face, a plurality of abrasive segments mountgle stop mounted on the chuck which engages the ends of all of the segments to adjustably position their operative faces in alignment, and means to secure the stop in one of several predetermined positions to locate the segments as desired.

3. A grinding wheel comprising a chuck having a supporting ring, a plurality of abrasive segments mounted against a curved surface of said ring, individually adjustable clamping blocks, each engaging two adjacent segments to secure them on the ring, and a single stop interlockingly secured on said ring which is adjustable to one of several predetermined and spaced positions and which engages the ends of all of the segments when secured in each of these adjusted positions and maintains their grinding faces aligned to form a flat grinding surface.

4. A segmental surface grinding wheel comprising a supporting ring, a plurality of abrasive segments shaped for mounting upon the surface of said ring, adjustable clamping blocks engaging adjacent segments to secure them on the ring, a stop ring rotatably mounted on the supporting ring and having several locking lugs, and means on the supporting ring to interlock therewith when the stop ring is rotated through a partial turn.

5. A segmentalsurface grindingwheel comprising a supporting ring, a plurality of abrasive segments shaped-for mounting upon the surface of said ring, adjustable clamping blocks engaging adjacent segments to secure them on the ring, a stop ring surrounding said supporting ring and having locking lugs, and means on the supporting member to interlock therewith when the parts are rotated relatively.

6. A segmental surface grinding wheel comprising a supporting ring, a plurality of abrasive segments shaped for mounting upon the surface of said ring, adjustable clamping blocks engaging adjacent segments to secure them on the ring, a stopring surrounding the supporting ring' 'and having locking lugs, and means including spaced projections on the supporting ring arranged to interlock with,

the lugs on the stop ring to secure the latter in one of several positions and locate the segments as desired.

7. A segmental surface grinding wheel comprising a supporting member, a plurality of abrasive segments mounted on the supporting member in. an adjusted position and extending beyond one edge thereof to present a flat grinding surface, clamping devices engaging the segment which are separately adjustable to press the segments against the surface of the supporting member, and a stop engaging the ends of several segments, said stop and supporting member having aplurality of interlocking parts which permit the stop to belocatedin any one of several positions or unlocked directly therefrom.

8. A'segmental grinding wheel comprising I a rotatable ring, a plurality of abrasive seg ments mounted thereagainst and projecting to form an exposed, substantially plane grinding face, clamping blocks adjustably secured .to the ring and engaging the segments to hold them. in position, a ring shaped stop engaging the ends of the segments to align their grinding faces and having spaced looking lugs thereon, and a plurality of rows of spaced members carried on the rotatable ring which may interlock with the lugs and hold the ring and the segments in one of several adgusted positions. t

A segmental surface grinding wheel comprising a supporting ring, abrasive segments for mounting thereupon, means to adjustably hold said segments against a peripheral surface of said ring includingspaced wedge blocks rigidly secured to said ring to support and correctly position opposed edges of adjacent segments, adjustable clamping blocks mounted on said ring and engaging the opposite sides of said segments to position the same so as to provide a flat grinding surface extending. beyond one edge of said ring, and an ad ustable stop engaging the end faces of the segments adapted to prevent endwise movement/thereof.

. 10. A segmental grinding wheel comprising a supporting ring, abrasive segments mounted thereon, means to adjustably hold said segments against a peripheral surface of said ring including spaced wedge blocks rigidly secured to said ring to support and correctly position opposed sides of adjacent segments, adjustable clamping blocks mounted on said ring and engaging the opposite sides of said segments to posltion the same so as to provide a flat grinding surface extending beyond the edge of said ring, a stop engaging the end faces of the segments adapted to prevent endwise movement thereof, and means for locating the stop in one of several adjusted positions to reposition the abrasive segments as they wear away.

11. A segmental surface grinding wheel comprising a supporting member, a plurality of projections integrally fixed thereto providing aligned surfaces adapted to locate a plurality of parallel planes, abrasive segments adjustably mounted upon the member, a movable stop surrounding said member and provided with a tongue adapted to engage those surfaces locating agiven plane, said stop being constructed and arranged to engage one end of each segment and maintain the opposite ends alignedduring grinding to form a fiat grinding surface beyond one edge of said member and facing in the same direction as said surfaces.

12. A segmental surface grinding wheel comprising a supporting member, a plurality of projections integrally fixed thereto providing aligned surfaces adapted to locate a plurality of parallel planes, abrasive segments adjustably mounted upon the member, a movable stop surrounding said member and provided with a plurality of tongues spacedso that said members may be moved to bring said tongues in engagement with any of those surfaces locating any one of a plurality of parallel planes, said stop being constructed and arranged to engage one end of each segment and maintain the opposite ends aligned during grinding to present a flat grinding surface beyond one edge of said member and facing in the same direction as said surfaces.

13. A segmental surface grinding wheel comprising a supporting member, a plurality of abrasive segments mounted upon said member between alternate fixed and adjustable clamping blocks so that the segments may be moved along an element of said member as desired, a plurality of projections integrally fixed upon the member providing aligned surfaces adapted to locate a plurality of different parallel planes, a movable stop surrounding said member and provided with a tongue adapted to engage the surfaces locating a given plane, said stop being constructed and arranged to engage one end of each segment and maintain the opposite ends aligned during grinding to present a flat grinding surface beyond one edge of said member.

14. An abrasive segment for use in a chuck having a convex cylindrical supporting surface comprislng a shaped mass of bonded abrasive grains having a plane grinding face, an inner surface provided with a pair of spaced projecting lands adjacent the ends of \the segment which are shaped to fit against and form the sole contact with the convex surface, and .an outer face havmg bevelled I clamping surfaces adjacent to its ends which converge outwardly and are shaped to be en-

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