Title of Invention: Method for manufacturing a sweeper or abrasive element and such element
Abstract: A method for manufacturing a sweeper or abrasive element is disclosed. The abrasive element is manufactured from a U-shaped plastic profile having an aperture in which are placed abrasive lamellae, supporting bristles and heat-dissoluble plastic threads. By heating above the plasticization temperature of the plastic, total embedding of the bristles and abrasive lamellae occurs thereby forming an integral unit. This ensures that the bristles and/or abrasive lamellae will not separate during use of rotating abrasive or polishing tools in which the abrasive elements are included. As the abrasive elements are of plastic material they are flexible and able to adapt to different diameters of abrasive or polishing tools. The user, therefore, only needs to have a supply of abrasive elements, cut into suitable lengths depending on the diameter of the tool in which the abrasive elements are to be replaced.
Detailed Description: Part PAR: FIG. 1 illustrates an apparatus 1 for the manufacture of abrasive elements 2 by a method according to the invention.
Part PAR_2: According to the method, a flexible U-shaped profile 3 is conveyed from a feeding roller (not shown). The two legs of the U-shaped profile are spread apart in a station 4. Immediately thereafter an adhesive member 5 in the form of a plastic thread or alternatively of a double-sided adhesive tape is introduced into this station. The adhesive member 5 is introduced in vicinity of one leg of the U profile and immediately next to it abrasive lamellae 6 are introduced, which will thus lie adjacent the first of the two legs of the U profile 3.
Part PAR_3: As appears from the figure, the abrasive lamellae 6 are formed by slitting a web-shaped abrasive cloth and are part of the web width. In this manner a coherent edge area 6' appears, which is introduced into the U profile 3 and which ensures a mutual retention of the abrasive lamellae 6. It is preferred for the cut of the abrasive cloth web to be performed in such a manner that during the slitting the abrasive lamellae are given a slight turn so that the abrasive side is oriented at an angle between 2.degree. and 5.degree. in relation to the longitudinal direction of the abrasive element.
Part PAR_4: After introducing the abrasive lamellae, rigidifying bristles 7 are arranged between the two legs of the U. The bristles 7 are conveyed from a supply source 8 where they are given a uniform orientation in a vibration device or similar device. The bristles are then transferred to an endless conveyor belt 9, which conveys the bristles 7 with an extension transverse of the U profile. The conveyor belt 9 has a direction of conveyance according to the arrow 10. Projecting walls 11 are positioned transversely of the conveyor belt 9. Between the subsequent walls 11 a number of bristles will be situated, which are laid down between the U profile legs at the point 12, a directing member 13 pressing the central part of the bristles into the bottom of the U profile. Immediately afterwards a thread-shaped adhesive member in the form of a dissoluble plastic thread 14 is introduced between the U legs. The plastic thread 14 is conveyed from a supply roll (not shown) around a roller 15 and laid down by means of a positioning member 16 corresponding to the positioning member 13. In this manner it is ensured that the plastic thread 14 is brought into folded bristles 7 and into the bottom of the U profile. Thus, the folded rigidifying bristles 7 will be positioned at the second U leg in a position alongside the abrasive lamellae 6.
Part PAR_5: It is noted that the process of introducing the bristles 7 and the plastic thread 14 may alternatively be introduced simultaneously by positioning the plastic thread in immediate vicinity of the conveyor belt so that it extends in a track between subsequent walls 11 and, thus, will keep the bristles 7 in contact with the conveyor belt and in such a manner that the plastic thread 14 will be laid down into the bottom of the U by the positioning member 14, which folds and conducts the rigidifying bristles 7 into the U bottom.
Part PAR_6: At this moment the spreading of the U profile will cease, and the U profile with the bristles, abrasive elements and plastic thread arranged therein is now conducted to a unit 17 where the upper ends of the two legs are brought towards each other in order to squeeze the lamellae and bristles. The unit 17 is provided with heating members so that a heating above the plasticisation temperature of the plastic thread 14 is performed simultaneously. The temperature will simultaneously lead to at least a partial plasticisation of the U profile so that plastic from the plastic thread and the inner side of the U profile is made to enclose the bristles 7 and the abrasive lamellae 6 for formation of an integral unit. Plastic from the plastic thread 14 and the U profile 3 will thus coalesce and form a completely integral unit, wherein the bristles 7 and the lamellae 6 are embedded and form a part. It will then not be possible to separate the different components from each other without ruining the abrasive element formed. The U profile is then cooled under the plasticisation temperature. This may preferably take place in the last half of the unit 17. Alternatively a separate cooling unit may be applied.
Part PAR_7: The elongated abrasive element thus formed is then conducted to a unit 19 in which the aligned bristles 7 and abrasive lamellae 6 are separated. The abrasive lamellae are brought aside so that the bristles 7 may be cut to a uniform length. In the figure it is shown at point 18 how the abrasive lamellae are laid down and the bristles 7 appear with non-uniform length. After passage through a cutting member 19' in the unit 19 the bristles appear with uniform length at a position 20. This cutting of the bristles 7 is advantageous for manufacturing an abrasive element 1 that is ready for use directly after it has left the manufacturing apparatus.
Part PAR_8: After the bristles 7 have been cut, the separation or spreading of the abrasive lamellae or the bristles will cease. The abrasive element may then be cut into desired lengths in a cutting unit 21. Then abrasive elements 2 in the desired length appear. Alternatively it is possible to manufacture the abrasive elements in endless lengths, which are wound onto supply rollers, which may then be delivered to the user, who may shorten the abrasive elements into the lengths he desires. Winding onto rollers is possible because the U-shaped plastic profile has sufficient flexibility to be wound.
Part PAR_9: It is noted that as an alternative to the use of a plastic profile, a U profile of rubber or other flexible material may also be used. It should only be ensured that the profile has such flexibility or compliance that it is able to adapt to different diameters when the profile is inserted into tracks on an abrasive or polishing tool.
Part PAR_10: In order to produce an abrasive element that is directly ready for use and that may easily be fastened in such a tool, the unit 17 will be designed in such a manner that during heating and subsequent cooling a static deformation of the U profile is performed so that the cross-section contour will have a larger dimension at the U bottom than at the abrasive lamellae and the bristles. Due to this the U profile may be inserted into undercut tracks, which may for example be dovetailed or T-shaped. Thus, the abrasive element thus produced may easily and quickly be inserted into existing abrasive or polishing tools, the cylinder surfaces of which are provided with tracks that have previously been designed to receive abrasive elements having a metal U profile.
Part PAR_11: Thus, the user does not need to store a large number of abrasive elements that are adapted to different diameters of the tools.
Part PAR_12: In FIG. 2 an abrasive element is seen such as it will appear immediately after laying down the plastic thread 14 but before heating and deformation. Thus, the U will have its legs spread apart. In the condition shown the legs of the U are spread to a state in which they extend in parallel with each other. Alternatively the U legs may be spread even wider in order to create as much space as possible between the legs. It is seen that the abrasive lamellae 6 are introduced at the first leg 22 whereas the bristles 7 are introduced in vicinity of the second leg 23 of the U profile.
Part PAR_13: In FIG. 3 the U profile is seen in its completed form with shortened bristles 7 and with the U profile 3 deformed into a state in which the cross-section contour has a larger dimension at the U bottom 24 than at the U top 25 at the bristles 7 and abrasive lamellae 6 projecting therefrom. It is seen here that the thread 5, the abrasive lamellae 6, the bristles 7 and the thread 14 inside the U profile form an integral unit, which may be conceived of as a plastic matrix in which part of the threads 7 and part of the abrasive lamellae 6 are embedded. It has been said above that part of the plastic of the U profile is plasticised. It is noted, however, that this is not necessary. Thus, it may be sufficient that the threads 5 and 14 are plasticised and fill out the cross section area inside the deformed U profile together with the bristles 7 and the abrasive lamellae 6. When the deformed U profile is displaced into an undercut track in an abrasive or polishing tool, the bristles 5 and the lamellae 6 will still be retained in the U profile since the integral coalesced unit filling the U profile will be retained therein as the dimensions at the top 25 of the U profile is smaller than the dimension at the bottom 24 of the U profile.
Part PAR_14: In FIGS. 2 and 3 a metal lining 26 is shown. The metal lining is optional and is used in order to contribute to establishing a squeeze around the sweeper bristles or the rigidifying bristles and abrasive lamellae in addition to the retention effect obtained due to the compression of the two legs 22, 23 of the U.
Part PAR_15: The metal lining 26 is produced with a plate-shaped part 27 designed to be placed embedded in the bottom 28 of the U-shaped profile. At either side of the plate-shaped part 27 tooth-shaped or comb-shaped projections 29 are formed, which are designed to extend partially into the legs 22, 23 of the U-shaped profile.
Part PAR_16: When an element is manufactured and the legs 22, 23 have been pressed back against the bristles/lamellae, the tooth-shaped projections 29 may be given an inwardly oriented fold so that they contribute to retaining the profile legs 22, 23 in their oblique inwardly oriented position where they squeeze the embedded bristles/abrasive lamellae. In this manner the risk of an unintended separation of the plastic profile and the bristles/abrasive lamellae positioned therein is reduced during transport, storage and handling of a sweeper or abrasive element before it is mounted in a tool.
Part PAR_17: In FIGS. 4 and 5 a cross-section, respectively a side view of a lining 26 is seen. It is noted, however, that the tooth-shaped projections may have other shapes than the severed triangles shown. It is only important that the projections 29 have such a shape that the formed sweeper or abrasive element 2 may easily be bent in the plane perpendicular to the bottom 28 of the U-shaped profile so that the element may easily be adapted to the curve of the tool in which it is to be mounted.
Part PAR_18: The lining will preferably be produced from aluminium but other very flexible metals may also be used.


{'bibliographic_information': "{'Patent Number': '062171240', 'Series Code': '9', 'Application Number': '1552074', 'Application Type': '1', 'Art unit': '174', 'Application Filing Date': '19980924', 'Title of Invention': 'Method for manufacturing a sweeper or abrasive element and such element', 'Issue Date': '20010417', 'Number of Claims': '10', 'Exemplary Claim Number(s)': '1', 'Assistant Examiner': 'Olsen; Kaj K.', 'Primary Examiner': 'Warden, Sr.; Robert J.', 'Number of Drawing Sheets': '2', 'Number of figures': '5'}", 'source_file': './grant/2001/pftaps20010417_wk16.txt', 'source_data': 'USPTO-Grant'}