WO2018054441A1

WO2018054441A1 - Abrasive element for abrasive drums or abrasive discs

Info

Publication number: WO2018054441A1
Application number: PCT/DK2017/050302
Authority: WO
Inventors: Tommy CHRISTIANSEN
Original assignee: Gito Holding Aps
Priority date: 2016-09-20
Filing date: 2017-09-20
Publication date: 2018-03-29
Also published as: EP3515663A1

Abstract

The invention relates to an abrasive element (100) for cylindrical drums (400) or abrasive discs comprising an abrasive cloth (200) and a keder (300), where the keder (300) comprises a main region (310), a neck region (320) and one or more flanges (330), and where the abrasive cloth (200) is fixed to one or more of the flanges (330) of the keder (300).

Description

ABRASIVE ELEMENT FOR ABRASIVE DRUMS OR ABRASIVE DISCS

Technical field of the invention

The invention relates to cylindrical drums or abrasive discs. More specifically, the invention relates to an abrasive element for cylindrical drums or abrasive discs.

Background of the invention

DK177274 discloses a grinding head designed to rotate about a central axis, and having a surface provided with retainer grooves for edge profile parts of a number of abrasive paper members with associated support brushes, which seen in the direction of rotation are placed behind the abrasive paper members. The drawback of this solution is that there is a certain requirement to the length of the abrasive paper elements in order to achieve the necessary flexibility of the abrasive paper elements during the grinding for optimising the grinding. In addition, it is a drawback of this solution that both support brushes and abrasive paper members must be replaced simultaneously even though the abrasive paper members are worn-down first. Moreover, the manufacturing of such abrasive paper members with associated support brushes is difficult and expensive.

US 2007/0010183 discloses a brush module for a rotating grinding brush, said brush module comprising: an elongated body part; at least one abrasive paper protruding from the base; and at least one brush also extending from the base substantially in the same direction as the abrasive paper. The abrasive paper is fastened to the base by a holder which in the one end comprises two flanges between which the abrasive paper is fastened, and in the other end comprises an elongated strand configurated to fasten the holder in the base. The strand is manufactured of either metal or plastic. The drawback of the holder fastening the abrasive paper as disclosed in US 2007/0010183 is that the strand fastening the abrasive paper to the rotating grinding brush cannot be used in twisted wheels and that the length of the abrasive paper when delivered has a length limitation in practice, as it is a matter of how long lists of abrasive paper can be delivered and handled.

Summary of the invention

Thus, it is an object of the present invention to separate the abrasive paper member from the support brush, and to provide an easier and less expensive method for manufacturing the abrasive paper members. It is also an object of the present invention to provide an abrasive paper member with an improved shape suited to any type of cylindrical drum or abrasive disc that you would wish to use, for instance in case you wish to use a traditional cylindrical drum or abrasive disc having a straight groove or in case you wish to use a twisted cylindrical drum or twisted abrasive disc having a groove twisting across the cylindrical drum or the abrasive disc.

A first aspect of the present invention relates to an abrasive element for cylindrical drum or abrasive disc comprising an abrasive cloth (200) fixed to a base (305), where the base (305) comprises a flexible material.

By the term "base" in the current context is understood the edge part to which the abrasive cloth is fastened and which secures the abrasive element in the cylindrical drum or the abrasive disc as described herein.

By the term "flexible material" in the current context is understood a flexible material which is resilient and a material being able to change its form under force application and which material returns to its original form, or basically returns to its original form when the force is no longer applied. Dependent on the use of the abrasive element or the flexible material, it is obvious to the person skilled in the art which flexibility is necessary.

It is obvious to the person skilled in the art what is meant by flexible material compared to inflexible materials, such as e.g. metal and plastic, as they cannot change form while force is applied and subsequently basically return to their original form. In an embodiment, the flexibility of a material can be determined by measuring the deflection (U) of a material having a constant length (L) influenced by a force (F). The flexibility can thus be measured by taking a material having a length of 100 mm and exposing the end of the material to a force of 100 gram, and measure the deflection/the flexibility (U).

According to one or more embodiments in connection with the present invention, the flexible material (when the abrasive cloth is mounted) has a flexibility (U) measured by a material having a length of 100 mm, where the end of the material is exposed to a force of 100 gram), a deflection/a flexibility of at least 0,2 cm; such as 0,5 cm; e.g. 0,75 cm; such as 1 ,0 cm; e.g. 1 ,5 cm; such as 2,0 cm; e.g. 2,5 cm; such as 3,0 cm; e.g. 4,0 cm.

According to one or more embodiments, the abrasive cloth (200) has a length (in the direction, when mounted, perpendicular to the longitudinal direction of the abrasive element (100)) of less than 40 mm, preferably less than 30 mm, more preferably less than 25 mm, more preferably around 20 mm.

According to one or more preferred embodiments, the base (305) is a keder (300), where the keder (300) comprises a main region (310), a neck region (320) and one or more flanges (330), and where the abrasive cloth is fixed to one or more of the flanges (330) of the keder.

A second aspect of the present invention relates to an abrasive element for cylindrical drums or abrasive discs comprising an abrasive cloth and a keder.

A third aspect of the present invention relates to an abrasive element for cylindrical drums or abrasive discs comprising an abrasive cloth and a keder, where the keder comprises a main region, a neck region and one or more flanges, and where the abrasive cloth is fixed to one or more of the flanges of the keder.

By the term "keder" in the current context is understood a sheet material, preferably a textile material or polymer material, which is entirely or partly packed around a strand (preferably flexible strand) of polymer material (head of the keder/main region), and welded together (for instance by gluing, fusion or sewing) during the formation of a neck region (neck of the keder/neck region). From the neck region, a sheet material extends into one or two (or more, such as three and four) flanges. A keder may also be an extruded product in the same shape as the above and where sheet material and strand are of the same material or of different materials. A keder may therefore be shaped in one piece.

The advantage of using a keder of textile material or polymer material entirely or partly packed closely around the strand (preferably flexible strand) is i.a. that insertion of the abrasive element in the cylindrical drum or in the abrasive disc is facilitated.

According to one or more embodiments, the main region of the keder comprises a core and an outer layer, and where the core comprises a strand of polymer material and the outer layer comprises a sheet material, and where the outer layer entirely or partly, preferably entirely, comprises the strand of polymer material and continues into the formation of the neck region and one or more flanges. By the term "strand" in the current context is understood a continuous structure which may be of one single material or a composite. The structure may be woven of smaller fibres, and may also be a composition of thinner continuous structures which are braided or twisted. Moreover, the structure may be extruded with for example a core and a shell. The choice of structure may depend on strength and price. According to one or more embodiments, the sheet material is selected from the group consisting of a woven textile material, a non-woven textile material, a polymer material or composites thereof. The abrasive cloth is fixed to the flange(s) of the keder. When the keder comprises two flanges, the abrasive cloth is fixed between the flanges. However, an abrasive cloth can alternatively be fixed to each of the flanges, if the cylindrical drum or the abrasive disc is to be able to operate (rotate) in both directions. The fixation of the abrasive cloth to the flange can be done by gluing, welding, sewing, fusion or the like or a combination thereof, e.g. gluing and/or sewing or welding and/or sewing.

According to one or more embodiments, the keder comprises two flanges, which may be symmetrical or asymmetrical in their extent. The advantage of an asymmetrical flange may be that the active side of the abrasive cloth (grained side) is fastened to the short flange, and the passive side of the abrasive cloth is fastened to the longer flange. In this way a strong anchorage with minimal covering of the active side of the abrasive cloth is achieved. However, in some embodiments, the abrasive cloth may have two active sides, if the cylindrical drum or the abrasive disc is to be able to operate (rotate) in both directions.

According to one or more embodiments, the abrasive cloth comprises an active side and a passive side. According to one or more embodiments, the active side comprises an abrasive material.

According to one or more embodiments, the abrasive cloth comprises an abrasive material and a sheet material. According to one or more embodiments, the sheet material is selected from the group consisting of a woven textile material, a non-woven textile material, a polymer material, a plastic material or composites thereof. According to one or more embodiments, the abrasive material covers 10-95% of the active side of the abrasive cloth, such as 15-90%, e.g. 20-80%, such as 25- 70%, e.g. 30-60%, such as 35-50%, e.g. 40-45%.

According to one or more embodiments, the abrasive material consists of particles or powder of e.g. stone, sand, metal, ceramic materials, diamonds or the like.

According to one or more embodiments, the abrasive cloth is fixed to the flange or the flanges. The abrasive cloth may be fixed to the flange by gluing, welding, sewing, fusion or the like or a combination thereof, e.g. gluing and/or sewing or welding and/or sewing.

The dimensions of the keder and the abrasive cloth depend on the specific application.

According to one or more embodiments, the flange has a length of 2-30 mm, such as between 5-20 mm, such as 8-12 mm.

According to one or more embodiments, where the flanges are asymmetrical, the difference of the length of the two flanges is 1 -15 mm, such as between 5-10 mm.

According to one or more embodiments, the main region has an outer diameter of between 2-30 mm, such as between 3-25 mm, such as between 4-20 mm, such as between 5-15 mm. According to one or more embodiments, the abrasive cloth has a length (in the direction, when mounted, perpendicular to the longitudinal direction of the main region of the keder) of 10-100 mm, such as 20-80 mm, e.g. 30-60 mm, such as 15-25 mm, typically around 20 mm.

According to one or more embodiments, the abrasive cloth has a length (in the direction, when mounted, perpendicular to the longitudinal direction of the abrasive element) of less than 40 mm, preferably less than 30 mm, more preferably less than 25 mm, more preferably around 20 mm.

This length of the abrasive cloth comprises both the part of the abrasive cloth fastened to the flange and the part of the abrasive cloth not fastened to the flange.

According to one or more embodiments, the abrasive cloth has a width (in the direction, when mounted, parallel to the longitudinal direction of the main region of the keder) of 10-3000 mm, such as 50-1000 mm, e.g. 100-500 mm.

According to one or more embodiments, the abrasive cloth has a length (in the direction, when mounted, perpendicular to the longitudinal direction of the main region of the keder) shorter than the width (in the direction, when mounted, parallel to the longitudinal direction of the main region of the keder).

According to one or more embodiments, 1 -30%, such as between 2-25%, such as between 3-20%, such as between 4-15%, such as 5-10% of the length of the abrasive cloth is covered by the flange.

According to one or more embodiments, the neck region of the keder has a length between 0-10, preferably between 1 -8 mm, preferably between 2-6 mm, preferably between 3-5 mm. A fourth aspect of the present invention relates to a cylindrical drum or abrasive disc comprising one or more grooves for mounting one or more abrasive elements according to the invention.

In connection with the present invention, the structure of the cylindrical drum or the abrasive disc may vary so that in one embodiment, the cylindrical drum or the abrasive disc may have a straight groove, while in a second embodiment, the cylindrical drum or the abrasive disc may have a twisted groove twisting across the cylindrical drum or the abrasive disc (the twisted cylindrical drum or the twisted abrasive disc). The choice between twisted or straight groove depends on the use or the purpose of the grinding.

According to one or more embodiments, the groove of the twisted cylindrical drum or the twisted abrasive disc is twisted by 2-40° compared to cylindrical drums or abrasive discs having a straight groove, such as 5-30°, e.g. 10-25°, such as 15-20°.

According to one or more embodiments, the groove is shaped as a channel with an open first end, an open or closed second end, and a guide opening extending from at least the first end and towards the second end; where the guide opening is adapted to receive the neck region of the keder, and where the channel is adapted to receive the main region of the keder, when the main region is inserted through the open first end of the channel; and where the guide opening is narrower than the diameter of the main region so that the main region of the keder cannot be pulled through the guide opening when the keder is mounted in the groove. According to one or more embodiments, the cylindrical drum or the abrasive disc furthermore comprises a securing means for closing the open first end of the channel.

According to one or more embodiments, the securing means is shaped as one or more detachable plate(s) shaped so that the plate when mounted covers the first end of all channels.

According to one or more embodiments, the detachable plate comprises one or more elongated pin holes, and where the pin hole comprises a first part and a second part, where the first part is adapted to receive a head of a pin mounted on the cylindrical drum or the abrasive disc, and where the second part is adapted to be able to receive only the neck of a pin mounted on the cylindrical drum or the abrasive disc. Preferably, the detachable plate comprises two or more elongated pin holes. Thereby, the detachable plate can be twisted off instead of traditional mounting with for instance screws.

According to an alternative embodiment, the detachable plate comprises one or more elongated pin holes, and where the pin hole comprises a first part and a second part, where the first part is adapted to receive a head of a pin mounted on the cylindrical drum or the abrasive disc, and where the second part is adapted to be able to receive only the neck of a pin mounted on the cylindrical drum or the abrasive disc. Moreover, the detachable plate comprises a recess interacting with a resilient pressure piece, preferably in the shape of a bead, mounted on the cylindrical drum or the abrasive disc, when the detachable plate is mounted on the cylindrical drum or the abrasive disc.

According to one or more embodiments of the present invention, the pin may either be an integrated part of the cylindrical drum or the abrasive disc, or possibly moulded therein or the pin may be a screw/bolt screwed into the cylindrical drum or the abrasive disc and about which the pin hole can be rotated. According to one or more embodiments, the cylindrical drum or the abrasive disc moreover comprises one or more grooves for mounting one or more brushing elements.

A fifth aspect of the present invention relates to a brushing element for cylindrical drums or abrasive discs comprising one or more bundles of bristles and a keder, where the keder comprises a main region, a neck region and one or more flanges, and where the bundles of bristles are fixed to one or more of the flanges of the keder.

A sixth aspect of the present invention relates to a cylindrical drum or abrasive disc comprising one of more grooves for mounting one or more abrasive elements, and a securing means; and where the securing means is shaped as one or more detachable plate(s) shaped so that the plate/plates when mounted covers/cover the first end of all channels.

According to one or more embodiments, the securing means is shaped as one or more detachable plate(s) shaped so that the plate/plates when mounted covers/cover the first end of all channels. According to one or more

embodiments, the detachable plate(s) comprises/comprise one or more elongated pin holes, and where the pin hole comprises a first part and a second part, where the first part is adapted to receive a head of a pin mounted on the cylindrical drum or the abrasive disc, and where the second part is adapted to be able to receive only the neck of a pin mounted on the cylindrical drum or the abrasive disc.

Preferably, the securing means comprises a detachable plate comprising two or more elongated pin holes. Thereby, the detachable plate can be twisted off instead of traditional mounting with for instance screws. It should be noted that embodiments and features described in the context of one of the aspects of the present invention also apply to the other aspects of the invention.

Brief description of the figures

Figure 1 shows a cross-section of two preferred embodiments of a keder according to the invention;

Figure 2 shows an abrasive element according to the invention;

Figure 3 shows a preferred securing means for a cylindrical drum according to the invention;

Figure 4 shows a cylindrical drum with mounted abrasive elements and a securing means for the cylindrical drum according to the invention.

Figure 5 shows a method for determining the flexibility of a material by measuring the deflection (U) of a material having a constant length (L) influenced by a force (F). Thus, the flexibility/the deflection can be measured by taking a material having a length of 100 mm and exposing the end of the material to a force of 100 gram, and measure the deflection/the flexibility (U). Subsequently, the material will return to or basically return to its original form.

Figure 6 shows an example of a twisted cylindrical drum without inserted abrasive elements according to the invention.

Figure 7 shows a cylindrical drum and a securing means for the cylindrical drum according to the invention. Detailed description of the invention

An aspect of the present invention relates to an abrasive element 100 for cylindrical drums or abrasive discs. The abrasive element 100 comprises an abrasive cloth 200 and a base 305 in the shape of a keder 300 (Figure 2). Figure 1 shows a cross-section of two preferred embodiments 300A/305A and

300B/305B of a base in the shape of a keder according to the invention. In general, the keder 300 comprises a main region 310, a neck region 320 and one or more flanges 330. The first embodiment 300A comprises only one flange, and the second embodiment 300B comprises two flanges 330.

The main region 310 of the keder 300 comprises a core 312 entirely or partly comprised by an outer layer 314, and where the core comprises a strand of polymer material and the outer layer comprises a sheet material, and where the outer layer continues into the formation of the neck region (320) and one or more flanges (330). In figure 2, the abrasive cloth 200 is fixed to the flange 330.

Figure 3 shows a preferred securing means 500 for a cylindrical drum according to the invention. The securing means 500 is shaped as a detachable plate 505, and shaped so that the plate 505 when mounted covers the first end of all channels. The detachable plate 505 comprises two elongated pin holes 510. The pin hole 510 comprises a first part 512 and a second part 514. The first part 512 is adapted to receive a head of a pin mounted on the cylindrical drum, and where the second part 514 is adapted to be able to receive only the neck of a pin mounted on the cylindrical drum. Thereby, the detachable plate can be twisted off and on instead of traditional mounting with for instance screws.

Figure 4 shows a cylindrical drum 400 with mounted abrasive elements 100 according to the invention. The cylindrical drum 400 comprises more grooves 410 for mounting more abrasive elements. The groove 410 is shaped as a channel having an open first end 412, a closed second end 414, and a guide opening extending from at least the first end 412 and towards the second end 414. The guide opening is adapted to receive the neck region of the keder, and the channel is adapted to receive the main region of the keder, when the main region is inserted through the open first end 412 of the channel. The guide opening is narrower than the diameter of the main region so that the main region of the keder cannot be pulled through the guide opening when the keder is mounted in the groove 410. At the end of the channel's first end securing means 500 is placed illustrated by the detachable plate 505 mounted so that the abrasive element 100 is secured inside the groove 410. When the detachable plate 505 is locked, the head of the pin 610 mounted on the cylindrical drum is led through a first part 512 of the detachable plate 505, and the detachable plate 505 is locked by rotating the detachable plate 505 clockwise so that a second part 514 of the detachable plate 505 secures the neck of a pin, thereby the detachable plate 505 can be mounted and dismounted by simple rotation instead of traditional mounting/dismounting with for example screws.

Figure 5 shows a method for deciding whether or not a material is considered being a flexible material according to the present invention. The deflection (U) is measured from a certain force (F) for a constant length (L). In an embodiment, the flexibility could be determined from a force of 100 g and a length of 100 mm. Thus, in an embodiment of the present invention, the flexible material in the current context has a deflection/a flexibility (U) according to said method of at least 0,2 cm; such as 0,5 cm; e.g. 0,75 cm; such as 1 ,0 cm; e.g. 1 ,5 cm; such as 2,0 cm; e.g. 2,5 cm; such as 3,0 cm; e.g. 4,0 cm. Figures 6a and 6b show two different angles of a twisted cylindrical drum 400 according to the invention. The twisted cylindrical drum 400 comprises more twisted grooves 410 for mounting more abrasive elements. The groove 410 is shaped as a channel having a guide opening extending from at least the first end 412 and towards the second end 414. The guide opening is adapted to receive the neck region of the keder, and the channel is adapted to receive the main region of the keder. The guide opening is narrower than the diameter of the main region so that the main region of the keder cannot be pulled through the guide opening when the keder is mounted in the groove 410. The dotted line in figure 6a helps illustrating the twisted shape that can twist 2-40° compared to the cylindrical drums or abrasive discs having straight grooves, such as 5-30°, e.g. 10-25°, such as 15-20°.

Figure 7 illustrates another embodiment of the preferred securing means 500 for a cylindrical drum according to the invention. The securing means 500 is shaped as a detachable plate 505 and shaped so that the plate 505 when mounted covers the first end of all the channels of the cylindrical drums. The detachable plate 505 comprises two elongated pin holes 510. The pin holes 510 comprise a first part 512 and a second part 514. The first part 512 is adapted to receive a head of a pin mounted on the cylindrical drum, and where the second part 514 is adapted to being able to receive only the neck of a pin mounted on the cylindrical drum. The pin may be an integrated part of the cylindrical drum, optionally moulded together with the cylindrical drum, or it may be a screw or a bolt mounted on the cylindrical drum about which the plate 505 can be rotated when it is mounted or dismounted. This way, the detachable plate can be twisted off and on instead of traditional mounting and fixation with for instance screws.

Moreover, the detachable plate 505 comprises a recess 507 interacting with a resilient pressure piece 615, preferably in the shape of a bead, mounted on the cylindrical drum or the abrasive disc, when the detachable plate is mounted on the cylindrical drum or the abrasive disc. Figures 7a and 7b show two cross-sections (cross-section A-A and cross-section

B-B) of a cylindrical drum 400 with a preferred embodiment of the securing means 500/505 in the shape of the detachable plate 505. When the detachable plate 505 is locked, the head of the pin 610 mounted on the cylindrical drum 400 is led through the pin hole 510. The detachable plate 505 is dismounted or mounted by rotating the detachable plate 505 counter clockwise and clockwise, respectively. When the detachable plate 505 is rotated, the resilient pressure piece 615, preferably in the shape of a bead, is pressed down until the pin 610 can be pulled out of the pin hole 510 or until the resilient pressure piece 615 on the cylindrical drum or the abrasive disc engages with the recess 507 on the securing means 500/505. In an alternative embodiment, the resilient pressure piece 615 could be placed on the securing means 500/505 and the recess 507 could be placed on the cylindrical drum or the abrasive disc.

Claims

1 . An abrasive element (100) for cylindrical drum or abrasive disc comprising an abrasive cloth (200) fixed to a base (305), where the base (305) comprises a flexible material.

2. An abrasive element (100) according to claim 1 , where the abrasive cloth (200) has a length (in the direction, when mounted, perpendicular to the longitudinal direction of the abrasive element (100)) of less than 40 mm, preferably less than 30 mm, more preferably less than 25 mm, more preferably around 20 mm.

3. An abrasive element (100) according to claims 1 or 2, where the base (305) is a keder (300), where the keder (300) comprises a main region (310), a neck region (320) and one or more flanges (330), and where the abrasive cloth is fixed to one or more of the flanges (330) of the keder.

4. An abrasive element (100) for cylindrical drum or abrasive disc comprising an abrasive cloth (200) and a keder (300), where the keder (300) comprises a main region (310), a neck region (320) and one or more flanges (330), and where the abrasive cloth is fixed to one or more of the flanges (330) of the keder.

5. An abrasive element (100) according to claim 3, where the keder (300) comprises two flanges (330) which are asymmetrical.

6. A cylindrical drum or abrasive disc (400) comprising one or more grooves (410) for mounting one or more abrasive elements (100) according to any of claims 1 -5.

7. A cylindrical drum or abrasive disc (400) according to claim 6, where the groove (410) is shaped as a channel with an open first end (412), an open or closed second end (414), and a guide opening extending from at least the first end (412) and towards the second end (414); where the guide opening is adapted to receive the neck region of the keder, and where the channel is adapted to receive the main region of the keder, when the main region is inserted through the open first end (412) of the channel; and where the guide opening is narrower than the diameter of the main region so that that the main region of the keder cannot be pulled through the guide opening when the keder is mounted in the groove (410).

8. A cylindrical drum or abrasive disc (400) according to claim 7, further comprising a securing means (500) for closing the open first end (412) of the groove (410).

9. A cylindrical drum or abrasive disc (400) according to claim 8, where the securing means (500) is shaped as a detachable plate shaped so that the plate when mounted covers the first end of all channels.

10. A cylindrical drum or abrasive disc (400) according to any of claims 6-9, where the securing means (500) comprises one or more elongated pin holes (510), where the pin hole comprises a first part and a second part, where the first part is adapted to receive a head of a pin mounted on the cylindrical drum or the abrasive disc, and where the second part is adapted to be able to receive only the neck of a pin mounted on the cylindrical drum or the abrasive disc.