Patent Publication Number: US-2019168360-A1

Title: Carrier body for grinding tools

Description:
BACKGROUND OF THE INVENTION 
     The present invention concerns a carrier body for grinding tools having an inner hub ring surrounding a central bore for connecting the grinding tool to a rotary drive, and an outer casing ring for receiving a grinding means, in particular in the form of a galvanic coating, a grinding ring or a plurality of grinding segments. The hub ring and the casing ring are connected together by way of a plurality of mutually spaced webs. The invention further concerns a grinding tool comprising such a carrier body. 
     EP 2 641 696 A1 discloses a carrier body. The aim set in the case of those carrier bodies is to save as much weight as possible and at the same time to make the carrier body as stable as possible. The first aim is successfully achieved in the structure in accordance with EP 2 641 696 A1. However it has turned out to be disadvantageous that the carrier bodies of EP 2 641 696 A1 expand to an unwanted degree, in particular with an increasing speed of rotation. There is also a need for improvement in the case of the carrier bodies of EP 2 641 696 A1 in regard to stiffness under the influence of lateral forces. 
     SUMMARY OF THE INVENTION 
     Therefore the object of the invention is to provide a carrier body which is improved over the state of the art and which on the one hand is greatly reduced in weight and which on the other hand enjoys adequate strength in relation to centrifugal forces and adequate stiffness in relation to lateral forces. In addition the invention seeks to provide a grinding tool having such an improved carrier body. 
     It is therefore provided according to the invention that the webs each have at least one respective opening. 
     By virtue of the provision of at least one respective opening in the webs it is possible with the webs to cover a greater spatial region without in that case the weight of the carrier body being increased. The strength in relation to centrifugal forces and stiffness in relation to lateral forces can be significantly improved and influenced by covering a greater spatial region. 
     A further great advantage is that the dynamic behaviour of the carrier body or a grinding tool including the carrier body can be influenced in specifically targeted fashion by the arrangement and the variation in the geometry of the webs and the at least one opening provided therein. 
     The strength and stiffness can be still further increased as described below. 
     As stated in the opening part of this specification protection is also claimed for a grinding tool having a carrier body according to the invention and a grinding means connected to the casing ring, in particular in the form of a galvanic coating, a grinding ring or a plurality of grinding segments. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Further details and advantages of the invention are discussed more fully hereinafter by means of the specific description with reference to the Figures in which: 
         FIGS. 1 a -1 d    show a first preferred embodiment of the carrier body according to the invention, 
         FIGS. 2 a -2 c    show a second preferred embodiment of the carrier body according to the invention, 
         FIG. 3  shows a third preferred embodiment of the carrier body according to the invention, 
         FIG. 4  shows a fourth preferred embodiment of the carrier body according to the invention, 
         FIGS. 5 a , 5 b    show a fifth preferred embodiment of the carrier body according to the invention, 
         FIG. 6  shows a sixth preferred embodiment of the carrier body according to the invention, and 
         FIGS. 7 a -7 c    show a seventh preferred embodiment of the carrier body according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1 a -1 d    show a first preferred embodiment of the carrier body  1  according to the invention, wherein  FIG. 1 a    shows a perspective view,  FIG. 1 b    shows a plan view of a first lateral surface  28 ,  FIG. 1 c    shows a plan view of the peripheral surface  47  and  FIG. 1 d    shows a plan view of the second lateral surface  18  of the carrier body  1 . 
     The carrier body  1  has an inner hub ring  7  which surrounds a central bore  8  for connecting the carrier body  1  or a grinding tool constructed by means of the carrier body  1  to a rotary drive. 
     The central bore  8  is of a radius  44  of between 50 mm and 150 mm, preferably 63.5 mm or 101.6 mm, wherein the radius  44  is measured from the center point of the central bore  8 , through which the axis of rotation  24  of the carrier body  1  passes, to the inner edge of the hub ring  7 . 
     The carrier body  1  further has an outer peripheral casing ring  9  for receiving a grinding means, in particular in the form of a galvanic coating, a grinding ring or a plurality of grinding segments. The hub ring  7  and the casing ring  9  are at a spacing  43  of between 50 mm and 150 mm, preferably 100 mm, relative to each other. That spacing  43  is measured from the outer edge of the hub ring  7  to the inner edge of the casing ring  9 . 
     The hub ring  7  and the casing ring  9  are connected together by way of a plurality of webs  10 , more precisely by way of a total of eleven webs  10  which are arranged relative to each other at a regular angular spacing  41 . The webs  10  are spacing from each other. Disposed between the webs  10  are openings  48  which in the present case are of an approximately trapezoidal configuration, with the corners of the trapezium being rounded. 
     The provision of a number of webs, wherein the number corresponds to a primary number and/or an odd number, is particularly advantageous as in that way the carrier body experiences particularly few vibrations. 
     The webs  10  each have a respective approximately triangular opening  13 . In addition the webs  10  have two web portions  18  and  19  spaced from each other by the opening  13 . Those web portions  18  and  19  have a common contact location  31  arranged adjacent to the hub ring  7 . Starting from that contact location  31  the web portions  18  and  19  extend away from each other in opposite directions in the direction of the casing ring  9 , that is to say the spacing of the web portions  18  and  19  relative to each other becomes greater in the radial direction. In other words the webs widen towards the casing ring  9  in the plane of the carrier body  1 . 
     The web portions  18  and  19  are further of an arcuate configuration and are of a mirror-image symmetrical configuration relative to a plane  25  oriented parallel to the axis of rotation  24  of the carrier body  1 . 
     A web portion  18  of a web  10 , with a web portion  19  of an adjacent web  10 , respectively forms a cut-off ogival configuration  26  (shown in broken line in  FIG. 1 b   ), wherein the tip  27  of the ogival configuration  26  which is notionally completed lies outside the casing ring  9 . 
     Instead of ogival configurations it is also possible to use parabolic arcs. 
     The carrier body  1  is of a radius  42  of between 200 mm and 300 mm, preferably 250 mm. 
     The casing ring  9  includes two outer webs  46 , between which the peripheral surface  47  is disposed. Those two webs  46  can be galvanically coated with a grinding means. That therefore affords two active grinding regions, with which two workpieces or two regions of a workpiece can be simultaneously machined. 
     A second preferred embodiment of the carrier body  2  according to the invention is shown in  FIGS. 2 a    through  2   c,  wherein  FIG. 2 a    shows a perspective view,  FIG. 2 b    shows a plan view of one of the lateral surfaces  28  of the carrier body  2  and  FIG. 2 c    shows a plan view of the peripheral surface  47  of the carrier body  2 . 
     As also in the first embodiment the carrier body  2  has an inner hub ring  7  which surrounds a central bore  8  for connecting the carrier body  2  or a grinding tool provided therewith to a rotary drive, and an outer casing ring  9  for receiving a grinding means, in particular in the form of a galvanic coating, a grinding ring or a plurality of grinding segments. A fixing ring  45  projecting in the axial direction is arranged at the inner hub ring  7 , the fixing ring  45  being provided at a side  28  of the carrier body  2 . 
     The hub ring  7  and the casing ring  9  are connected together by way of a plurality of, more precisely twelve, webs  11 , the webs  11  being spaced from each other by openings  49 . In this case the openings  49  are approximately in the shape of rectangles. 
     The webs  11  each have two openings  14  and  15  which are arranged in mutually displaced relationship in the radial direction. The openings  14  are in the form of a slot. The openings  15  are of a substantially circular cross-section. The openings  15  serve at the same time as fixing means, by way of which the lateral surfaces  28  of the carrier body  2  can be provided with cover means. 
     In this arrangement the cover means can extend from the fixing ring  45  to the inner edge of the casing ring  9 . 
     The webs  11  further have two web portions  20  and  21  spaced from each other by the openings  14  and  15 . The web portions  20  and  21  are connected together by way of two contact locations  31 . 
     The webs  11  widen towards the casing ring  9  and the hub ring  7  in the plane of the carrier body  2 . 
     The web portions  20  and  21  are of an arcuate configuration and are of a mirror-image symmetrical configuration relative to a plane  25  oriented parallel to the axis of rotation  24  of the carrier body  2 . 
     In addition a web portion  20  of a web  11 , with a web portion  21  of an adjacent web  11 , respectively form a cut-off ogival configuration  26  (see  FIG. 2 b   ), wherein the tip of the ogival configuration  26  which is notionally completed lies outside the casing ring  9 . Instead of ogival configurations it is also possible to use parabolic arcs. 
     In comparison with the first preferred embodiment (see  FIGS. 1 a  through 1 d   ), the carrier body  2  has a plurality of grooves at the peripheral surface  47 . In addition a delimiting projection  46  is provided only at one side of the peripheral surface  47 . 
       FIG. 3  shows a third preferred embodiment of a carrier body according to the invention as a plan view on a lateral surface of the carrier body  3 , that is oriented substantially normal to the axis of rotation. 
     As also in the two above-described embodiments the carrier body  2  includes an inner hub ring  7  surrounding a central bore  8  for connecting the carrier body  2  or a grinding tool provided therewith to a rotary drive, and an outer casing ring  9  for receiving a grinding means, in particular in the form of a galvanic coating, a grinding ring or a plurality of grinding segments. The hub ring  7  and the casing ring  9  are connected together by way of a plurality of webs  12 . The webs  12  are spaced from each other by openings  50 . Like also the openings  49  and  48  in the above-described embodiments, the openings  50  represent through apertures which extend over the entire thickness of the carrier bodies  1 ,  2  and  3 . In other words, at least in the region of the openings  48 ,  49  and  50 , it is possible to look through the carrier bodies  1 ,  2  and  3 . 
     The webs  12  each have two openings  16  and  17  which are spaced from each other in the radial direction and which are of a substantially triangular configuration, the triangles facing towards each other with a respective tip. 
     The webs  12  further have two web portions  22  and  23  which are spaced from each other by the openings  16  and  17  and which in turn are of an arcuate and mirror-image symmetrical configuration relative to a plane  25  oriented parallel to the axis of rotation of the carrier body  3 . 
     The web portions  22  and  23  intersect in this embodiment and form a contact location  31  at the point of intersection. 
     As also in the other two embodiments a web portion  22  of a web  11 , with a web portion  23  of an adjacent web  12 , respectively form a cut-off ogival configuration  26 , wherein the tips of the ogival configurations which are notionally completed lie outside the casing ring  9 . Alternatively the arcs  26  can also be of a parabolic configuration. 
     There are in all fifteen webs  12  which are arranged at uniform angular spacings  41  between the inner hub ring  7  and the outer casing ring  9 . 
     Provided at each fourth web  12  are fixing means  32 , by way of which the outer lateral surfaces  28  of the carrier body  3  can be provided with cover means. If necessary the fixing means  32  can also be provided at smaller spacings, therefore for example at each second web. 
     In principle it is also to be noted that the illustrated carrier body  3 , like also the other carrier bodies  1 ,  2 ,  4 ,  5  and  6  shown in the Figures, are of a substantially rotationally symmetrical configuration and are made from a metal. 
     The preferred embodiments  4 ,  5  and  6  shown in  FIGS. 4, 5   a  and  5   b  and  FIG. 6 , as regards the webs  12  provided between the hub ring  7  and the casing ring  9 , are of substantially the same structure as the third embodiment shown in  FIG. 3 . 
     Unlike the third preferred embodiment of  FIG. 3  however the fourth preferred embodiment of  FIG. 4  is divided into two, wherein the webs  12 , starting from a central plane  33 , are milled in the axial direction without however entirely breaking through the disks. Accordingly at the outer lateral surfaces there remains a respective thickness of material which serves as a closure or cover means  29 . The cover means  29  are thus connected in one piece to the webs  12  and the hub ring  7  as well as the casing ring  9 . As an alternative thereto however the cover means  29  could also be connected to the webs  12  and/or the hub ring  7  and/or the casing ring  9  by way of fixing means. 
     The halves  34  and  35  of the carrier body  4 , that are of a mirror-image symmetrical configuration relative to the central plane  33 , are releasably connected together at the central plane  33 . The fixing means  32  can be used for that purpose. 
     In the fifth preferred embodiment shown in  FIGS. 5 a  and 5 b   , where  FIG. 5 a    is a perspective view and  FIG. 5 b    is a sectional view along the sectional plane shown in broken line in  FIG. 5 a   , arranged in the central plane  33  of the carrier body  5  is a membrane  40  subdividing the carrier body  5  into two halves  36  and  37  which can be distinguished from each other. That membrane  40  prevents a flow of material between the lateral surfaces of the carrier body  5 . In this case therefore the openings  16 ,  17  and  50  do not extend over the entire thickness of the carrier body  5 . 
     The sixth preferred embodiment shown in  FIG. 6  is a variant of the fifth preferred embodiment, wherein a membrane  40  is again disposed in the central plane  33 . In comparison with the fifth preferred embodiment, the sixth preferred embodiment provides that the halves  38  and  39  of the carrier body  6  are identical and are arranged in mutually displaced relationship by a given angular spacing  41 , in this case half, of two adjacent webs  12 . 
       FIGS. 7 a  through 7 c    show a seventh preferred embodiment of a carrier body  30 ,  FIG. 7 a    being a perspective view,  FIG. 7 b    being a plan view of a lateral surface  18  of the carrier body  30 , that is oriented substantially normal to the axis of rotation  24 , and  FIG. 7 c    showing a plan view of the peripheral surface  47  of the carrier body  30 . 
     The carrier body  30  again comprises an inner hub ring  7  which surrounds a central bore  8  for connecting the carrier body  30  or a grinding tool including the carrier body  30  to a rotary drive, and an outer casing ring  9  for receiving a grinding means, in particular in the form of a galvanic coating, a grinding ring or a plurality of grinding segments. The hub ring  7  and the casing ring  9  are connected together by way of a plurality of webs  51 , the webs  51  each having a respective opening  52 . The webs  51  are spaced from each other by way of through apertures  57 . In all there are thirteen webs  51 . 
     The webs  51  each have two web portions  53  and  54  spaced from each other by the opening  52 , wherein the web portions  53  and  54  are of an arcuate configuration and are of a mirror-image symmetrical configuration relative to a plane  25  oriented parallel to the axis of rotation  24  of the carrier body  30 . 
     In addition a web portion  53  of a web  51 , with a web portion  54  of an adjacent web  51 , respectively forms an arc  55 , wherein the tips  56  of the arcs  55  touch the casing ring  9 . The arcs  55  are of a parabolic configuration. They could alternatively also be of an ogival configuration. 
     The angular spacing  41  of two adjacent webs  51 , the radius  42  of the carrier body  30 , the radius  44  of the central bore  8  and the spacing  43  of the hub ring  7  relative to the casing ring  9  can be of the dimensions specified in connection with the other embodiments.