Abstract:
A grinding ring having grinding covers for grinding profiled strips or profiled edges. The grinding ring includes a row of carrier segments, each carrier segment having grinding segments thereon. The grinding segments are connected with one another to form a one-piece grinding ring.

Description:
CROSS-REFERENCE  
       [0001]     This non-provisional application claims priority to and benefit of Provisional Application No. 60/702,618, filed Jul. 27, 2005, which disclosure is hereby incorporated by reference herein. 
     
    
     BACKGROUND AND SUMMARY  
       [0002]     The present disclosure relates to a grinding ring having grinding segments which are equipped with grinding covers or working surfaces. The grinding segments can be placed in an inverted position on a row of carrier segments of a rotatingly drivable segmental grinding wheel which extends in the circumferential direction. The grinding segments are configured to be used for the grinding of profiled strips or profiled edges made of wood or of a woody material.  
         [0003]     The grinding segments are made of a plastic material. The grinding covers are normally made of a woven fabric and form the working surface of the grinding segments. The shapes of the grinding segments depend on the cross-sections of the profiles to be ground. The machining of the profiles may be considered as a surface refinement because only the quality of the surface is to be improved. In order to achieve this effect, the segmental grinding wheels are driven at relatively low rotational speeds, for example, between 500 and 2,000 rpm. The grinding segments are wearing parts of the segmental grinding wheels, so that the grinding cover or working surface will be worn off after a certain operating time, requiring an exchange of all grinding segments of a segmental grinding wheel.  
         [0004]     The segmental grinding wheel may be designed as an individual segmental grinding wheel with one row of carrier segments extending in the circumferential direction or as a double segmental grinding wheel with two rows of carrier segments extending in the circumferential direction. If a double segmental grinding wheel is involved, the carrier segments are arranged such that they are mutually staggered so that the carrier segments of the first row engage in the gaps of the carrier segments of the second row. As a result, the working width of a double segment grinding wheel can also be changed.  
         [0005]     In the case of the previously known segmental grinding wheels, the grinding segments of each carrier segment row should be considered as an individual component part. After being placed on the carrier segments in an inverted position, they then have to be secured on both sides in a suitable manner. Those grinding segments have been very successful in practice. However, since they are required in large piece numbers in the pertinent industry, it should be possible to produce them in the most cost-effective manner and with high precision. Furthermore, it is a disadvantage of those grinding segments that they can be used only in a defined position relative to the axis of rotation of the segmental grinding wheel.  
         [0006]     The carrier segments, according to the present disclosure, include basic profile segments adapted to the cross-sections of the profiles to be ground. The basic profile segments are made of an elastic material, such as microcellular rubber and a metallic base, onto which the basic profile segments are placed. The carrier segments are fastened to a foundation.  
         [0007]     The present disclosure relates to grinding segments that can be produced in a simple and economic manner. Furthermore, a precision can be achieved that is as high as possible. Since the grinding segments are required in high piece numbers, the transport costs can also be reduced.  
         [0008]     The grinding segments, which can be placed in an inverted position on a row of carrier segments, are connected with one another and form a one-piece grinding ring. The individual grinding segments are foldable along defined weakening lines.  
         [0009]     By use of a suitable tool, the grinding segments forming a grinding ring are simultaneously produced in one working cycle. The grinding covers are applied in working cycles which follow. The economy of production is significantly increased by the simultaneous production of the grinding segments from a plastic material. An extremely high precision is obtained as a result of the design of the tool. Furthermore, it is advantageous that, as a result of the foldability of the grinding segments, they can be moved into a position in which a packing unit of a plurality of grinding rings has the smallest volume possible. Thus, either the packaging can be reduced for a certain number of grinding rings, or, in the case of packagings of the same size, the number of grinding rings or grinding segments is increased. It may also be that the transport costs can be lowered by approximately ⅓ in comparison to the transport costs for the previously-known grinding segments because the grinding segments of the present disclosure can be stacked correspondingly more tightly as a result of the folding.  
         [0010]     Furthermore, according to the present disclosure, the mounting of the grinding segments onto the carrier segments is simplified because the grinding ring can be precisely positioned and the grinding segments can then be placed in an inverted position onto the carrier segments by a slight application of force. Furthermore, the grinding segments may be used in every angular position within the angle in which they are foldable, so that the profiles to be ground by the grinding ring can have different cross-sections.  
         [0011]     According to the present disclosure, the weakening lines extend tangentially to an inner circle extending concentrically with respect to the axis of rotation of the grinding ring. As a result, undesirable deformations of the individual grinding segments in the area of the weakening line are avoided.  
         [0012]     For increasing the inherent stability, it is provided that the grinding ring has an inner can extending concentrically with respect to its axis of rotation. The outside diameter of this inner can is less than that of the inner circle. The design of the grinding ring within the inner circle depends on the construction of the respective segmental grinding wheel. Thus, the grinding ring could also be provided with a profiling. The weakening lines of the grinding ring may be constructed as film hinges. They can then already be inserted at the corresponding points in the course of the production of the grinding ring.  
         [0013]     The segmental grinding wheels can be securely fastened to the carrier segments. Each grinding segment includes at least two outward-oriented projections on mutually facing lateral surfaces which extend transversely to surfaces of the grinding segment carrying the grinding covers. The at least two outward-oriented projections engage in pockets of a tensioning device in a mounted condition of the grinding ring. As an alternative, it is also conceivable that each grinding segment includes a holding nose on the side facing away from the weakening line, a tension lid reaching over the holding nose in the operative condition. It should also be mentioned that the grinding segments, by corresponding forming methods, include molded parts adapted to the cross-sections of the profile and of the applied grinding cover. The grinding segments form a row of grinding segments, in which case they may be arranged such that the grinding segments of two grinding segment rows engage in one another. The grinding segments of one row of a segmental grinding wheel may also be called a set of grinding segments.  
         [0014]     Other aspects of the present disclosure will become apparent from the following descriptions when considered in conjunction with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]     FIGS.  1  to  4  are schematic views of a one-piece grinding ring having two grinding segments arranged thereon in a foldable manner and showing four different positions of the grinding segments, according to the present disclosure. 
     
    
     DETAILED DESCRIPTION  
       [0016]     The grinding ring  10  illustrated in FIGS.  1  to  4 , includes grinding segments  11  in an outer area. Grinding segments  11  are connected with a center part or area  12  via weakening lines  14  in the form of film or living hinges. Grinding covers are provided to cover grinding segments  11 . This center area  12  is an inner circle and the weakening lines  14  extend tangentially to this inner circle. In  FIGS. 1-4 , center area  12  has a flat construction. Center area  12  may also have a can-shaped or a hub-shaped construction, and an outer circumference may extend at a distance to the weakening lines  14  or to the grinding segments  11 . An axis of rotation of the grinding ring  10  is indicated by reference number  13 . The grinding ring  10  includes an inner can  16  extending concentrically to the axis of rotation  13 .  
         [0017]      FIG. 3  shows, for example, a position of the grinding segments  11 , arranged for packaging and/or transport in a flat position, in which a unit of grinding rings  10  could be combined as a packing unit. Furthermore, it is conceivable to design a tool such that the grinding rings  10  could also be removed in this form. However, grinding rings  10  may also be produced in the position as shown in  FIG. 1 .  
         [0018]      FIG. 1  shows the grinding segments  11  along the weakening lines  14  in a position bent downward at an angle a of, for example, 90°, which is an operative position of the grinding segments  11 .  FIG. 2  shows an intermediate position of a corresponding cross-sectional shape of profiles and an adapted shape and profile of the grinding segments  11 , which intermediate position could also be used as an operative position.  
         [0019]     Other profiles of the grinding segments  11  may be machined in which an enveloping angle amounts to 180°. That is because the grinding segments  11  may be folded over by an angle into the range of maximally 180°.  
         [0020]      FIG. 4  shows the grinding segments  11  folded about an angle of 180°, as compared to  FIG. 1 . Other intermediate positions of grinding segments  11  are conceivable. As shown in  FIGS. 1-4 , lateral, outward-oriented projections are identified by reference number  15 . In a mounted position of the grinding ring  10 , the projections  15  are disposed in pockets of a tensioning device. As suggested in  FIG. 3 , the grinding segments  11  may also be folded by 90° in both directions.  
         [0021]     The present disclosure is not limited to the illustrated embodiments. Grinding segments  11  are mutually connected to form a one-piece grinding ring  10 , and the grinding segments  11  can be folded along defined weakening lines  14 .  
         [0022]     Although the present disclosure has been described and illustrated in detail, it is to be clearly understood that this is done by way of illustration and example only and is not to be taken by way of limitation. The scope of the present disclosure is to be limited only by the terms of the appended claims.