The invention relates to abrasive stones that are detachably disposed on the inner surfaces of drums of washing machines that are used for the treatment which is generally called "stone washing" and applied to give textile garments a worn appearance, and methods of attachment of these stones to the drum surfaces and applications thereof.

BACKGROUND OF THE INVENTION

The treatment called "stone washing" of giving jean trousers made of denim cloth an aged, worn appearance by means of a washing process which was started to be used in 1970's and became common in 1980's. Today, many textile products besides jeans are stone-washed using different mechanical or chemical washing techniques. Pumice stone was the first technique in mechanical aging applications. Pumice stone, a natural volcanic rock, was used to be advantageous in the stone washing process thanks to its abrasive but light-weight structure as well as its ability to float on the water. However, the fact that it pollutes the process water by crumbling during the process causes environmental concerns, furthermore, since it loses its porous nature by deterioration, it cannot float on the water and forms a gritty sediment which in turn clogs the drains and sewage. Moreover, removal of the pumice stone from the garments at the end of the treatment requires extra labor cost and process time. After the washing cycle, the fabric is taken out of the machine to remove the pumice stone particles and after removal, the garments are loaded back to the machine both for the removal of the pumice residues and for the washings required by other chemical treatments. In order to eliminate the pumice stone removal step, pumice powder (sand) is also used as the mechanical abrasive, although it has a low efficiency. Abrasives with structures similar to pumice stone like expanded glass foam or marble sand are also used as mechanical abrasives. However, any mechanical abrasives being used pose environmental problems. Chemicals with bleaching, abrading or dye removal properties can also be used in washing, either together with the mechanical abrasives or alone. "Enzyme", which is a natural substance is widely used in the washing process either individually or along with the stone. Since it is natural, it is recognized as the least harmful substance utilized in denim washing. The enzymes referred here are the acidic or neutral celluloses ones. It is also very common to use sodium hypochlorite (NaCIO) or potassium permanganate (KMnO4) in bleaching process in aqueous applications for color fading in mechanical or chemical stone washing. Ozone gas fading has also been used widely as bleaching technique recently.

While numerous materials, methods, techniques and chemicals have been used in the last 30-40 years, the technology of the industrial stone washing machines with perforated cylindrical drums have not changed significantly. In the stone washing process, horizontal drum washing machines (belly-washing machines) with a high drum depth/drum diameter ratio and a loading/unloading port on the cylindrical surface of the drum can be used as well as the front loading washing machines with a relatively low drum depth/drum diameter ratio and loading/unloading port on the planar surface. Both the mechanical abrasives and the chemicals used in the stone washing process damage the drum surfaces; the former by abrading the drum and the paddle surfaces and the latter by causing corrosion on the surfaces they contact. In order to protect the drum surfaces in contact with the abrasives, which are

manufactured in stainless steel to be resistant to chemicals, coating said inner surfaces with materials that are cheaper and/or more resistant to abrasion than stainless steel have been used. However none of these methods have been successful in solving the problem. Furthermore, since the abrasive materials crumbled during the process are discharged with the waste water, the process creates environmental problems as well as problems in the drainage system. The storage and transportation of the pumice stone which is widely used as an abrasive, as well as its removal from the fabric at the end of the process poses several problems. The dust of the pumice stone causes wear and pollution both within the plants and in the environment at every step.

SUMMARY OF THE INVENTION

In the machine according to the present invention, the inner surfaces of the drum is covered with pieces of abrasive stones using various fastening techniques. The stone pieces are disposed on the cylindrical surface of the drum in such a way as to allow transfer of water through the perforations for discharging water from the drum. When required, in addition to the cylindrical surface, the paddles or other surfaces of the drum can also be covered by pieces of abrasive stone. Although it is possible to firmly bond or glue the abrasive stones onto the drum surface without using any attachment elements, replacement of the stone pieces would be difficult in such a case. For this reason, the suitably sized abrasive stones are mounted by means of attachment elements. Ability to retain the abrasive stones firmly on the drum surface, allowing easy assembly of the stones as well as easy replacement when they lose their function are the factors that need to be considered in selecting attachment elements. Abrasive stones mounted to the inner surface of the drum wear at different rates. The stones that have reached the end of their operational life will need to be replaced.

Employing an assembly method which allows local replacement without affecting the quality of the stone washing process will provide time and cost saving. Arranging the abrasive stones in the drum as small protrusions disposed adjacently will increase the mechanical effect and help to speed up the process and obtain a uniformly aged look thanks to the increased displacement of the fabric during the rotation of the drum. With the present invention, the problem of drum wear is completely eliminated as the mechanical abrasion in stone washing process in drum washing machines is performed by the pieces of abrasive stone mounted onto the inner surface of the drum. Time and cost savings in maintenance and replacement are achieved. Furthermore, • It is neither required to store or transport abrasives producing dust like pumice stone, nor to remove the residues from fabric at the end of the washing cycle, which results in a significant labor-saving.

• Since local and environmental pollution created by substances crumbling into dust and sand like pumice stone is prevented, an increase in production quality is accompanied by saving in labor, time, energy and consumables spent for water treatment, plumbing system maintenance and plant cleaning.

• Mechanical abrasives like pumice stone etc. causes temporary or permanent defects in the washing machine by being carried to every corner of the machine water can reach. For this reason, "stone washing" machines have shorter life spans in comparison to other washing machines. Abrasive stone implementation eliminates this drawback and extends the useful life span of the machines.

• Since it is no longer required to take the fabric out from the drum at the end of the stone washing cycle in order to remove pumice particles from the fabric, subsequent washing steps can take place continuously in the same machine, which in turn results in saving in cost and labor.

• It provides the option to select the abrasive properties and abrasive degree of the abrasive stones to be used according to the characteristics of the textile to be stone washed. · Abrasive stones can be used for long periods without requiring maintenance thanks to their extensive durability and this provides an economical advantage over pumice cost.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is the front view of a front-loading washing machine drum whose inner surfaces are covered with abrasive stones

Figure 2 is another view of the washing drum of Figure 1 where the front surface is not illustrated 20

Figure 3 is the detail view of a portion of the drum shown in Figures 1 and 2

Figure 4-A is an exploded isometric view of the combined piece composed of the attachment and the abrasive stone piece

Figure 4-B shows bottom and top isometric views of the combined piece Figure 4-C is a schematic view showing the details of the lug, lock pin tab and the locking pin which facilitate the attachment of the attachment to the drum

Figure 4-D is a detail view of the attachment lock pin tab of the last combined piece

Figure 5 is a schematic view illustrating assembly of the combined piece to the drum

Figure 6 is a schematic view of the combined pieces being mounted onto the perforated cylindrical surface of the drum

Figure 7-A is bottom isometric view of the multi-combined piece

Figure 7-B is a side isometric view of the multi-combined piece

Figure 7-C is a schematic view of the multi-combined pieces being mounted onto the perforated cylindrical surface of the drum Figure 8 A-C are the detail views of the multi-combined piece shown in Figure 7 A-C

Figure 9 is a schematic view of the multi-combined pieces with plastic attachments being mounted onto the perforated cylindrical surface of the drum

Figure 10 is a schematic view of the multi-combined pieces with metal attachments being mounted onto the perforated cylindrical surface of the drum Figure 11 is a detail view of the multi-combined piece with metal attachment on the drum surface

Figure 12-A is a bottom isometric view of the metal attachment of a multi-combined piece

Figure 12-B is a side isometric view of the attachment of the multi-combined piece and the abrasive stones before and after assembly

Figure 12-C is an isometric view of the assembly of the attachment of the multi-row multi-combined piece and the abrasive stones Figure 13 is a schematic view of the pieces of abrasive stones in stick form that are secured in the profiles of which both ends are closed with caps and which are mounted onto the cylindrical surface and the paddle surfaces of the drum

Figure 14 is detail view of the assembly of the profile and the stone pieces shown in Figure 10 to the perforated cylindrical surface of the drum

Figure 15 A-C is schematic views of the profiles of which one end is permanently closed and the other end is closed with a cap and which are mounted to the drum surface by using an assembly plate and of the stones

Figure 16 is the schematic view of the details of the insertion of the abrasive stone pieces into the stainless profile from the side thereof

Figure 17 A-D is the schematic view of the assembly details of the profile of which both ends are permanently closed and the last stone is secured by means of a locking member

Figure 18 is a schematic view of the assembly of the stones and the locking members to the profiles where the last stone is secured by a locking member

Figure 19 is illustrates examples of abrasive stone pieces schematically

LIST OF REFERENCE NUMBERS

10: Washing machine drum

11 : Piece of abrasive stone

12: Perforated cylindrical surface of the drum

13: Drum paddles

14: Front/"loading-door side" surface

15: Rear/"axle-support shaft-bearing side" surface

16: Drum perforations

17: Attachment

18: Combined piece

18': The last combined piece in a row

19: Indents on the members composing the combine piece 20: Protrusions on the members composing the combine piece 21 : protrusion of attachment piece

22: Lug on the protrusion of attachment piece

23: Puncture on the drum surface

24: Locking pin

25: Lock pin tongue

25': Lock pin tongue of the last combined piece

26: Lock pin slot (housing)

27: Lock pin tongue housing

28: Fastening holes

29: Attachment piece of the multi piece-combined part

30: Protective cap on the Attachment piece of the multi piece -combined part

31 : Multi-combined part

32: Stainless steel fastening profile

33: Rails of attachment profile

34: Piece of abrasive stone

35: Rail slot on the abrasive stone

36: Closed end of the profile

37: Removable cap at the profile end

38: Stone insertion opening

39: Profile assembly plate

40: Mating line of the two stones

41 : Cavity of the stone in the form of hole

42: Cavity of the stone in the form of hollow

44: Locking part for the last stone

44': Locking part of the last profile

46: First tongue of the locking part

48: Second tongue of the locking part

49: Locking opening

52: Bolt

52-2: Rivet nut DETAILED DESCRIPTION OF THE INVENTION

The invention relates to mounting pieces of abrasive stones on the inner surfaces of drums of front-or-side loading perforated drum-type washing machines used for the purpose of stone washing.

Figure 1 shows schematically a front loading perforated washing drum. The abrasive stones (11) that are to be mounted into the drum (10) can be attached by various assembling methods only to the perforated cylindrical surface (12) of the drum, but if required they can also be attached to other surfaces with which the fabric being washed can come into contact as the drum tumbles like the paddle surface (13), front- loading door side surface (14) or rear-axle support shaft bearing side surface (15).

When mounted onto the cylindrical surface (12), the stones (11) should not block the drum perforations (16) or block the flow of washing water through the openings.

Figure 2 shows schematically a front-loading drum (10) of which the front loading door side surface (14) is not illustrated and the perforated cylindrical surface (12), the paddle surfaces (13) and the rear surface (15) are all covered by pieces of abrasive stones in stick form.

Figure 3 shows schematically a closer view of a drum of which the perforated cylindrical surface (12), the paddle surfaces (13) and the rear-surface (15) are covered by pieces of abrasive stones (11) in in stick form. Textile items placed in the drum (10) of which at least some of the inner surfaces are covered with pieces of abrasive stones (11) as disclosed above rub against the stones (11) as the drum rotates in either wet or dry condition. This process is continued until the desired aged appearance is produced. The fabric is thereby mechanically abraded and obtained "stonewashed" appearance. The abrasive stones (11) arranged on the inner surfaces of the drum in pieces are also abraded over time and lose their function. The stones should be replaced by new ones when they become worn. It is important to make this replacement as quickly and easily as possible to save both time and labor. For this reason, the method by which the stones are attached to the drum surface, the form of this attachment and the connecting elements utilized therein are very crucial. There are various methods and ways of fastening the stones (ll) to the drum surfaces (12, 13, 14, 15). According to the bayonet connection illustrated in Figures 4 through 9, the abrasive stone piece (11) is permanently joined with an attachment (17) to obtain a combined piece (18) and said combined piece (18) is then mounted to the drum (10).

Figure 4-A is an exploded view of the combined piece (18) showing the stone (11) and the attachment (17) separately. The dimensions, shape and the content of the stone (11) may vary in accordance with the drum size and the particular application. When replacement is required, the stone (11) fastened in this manner is dismantled from the drum (10) together with the attachment (17) as the combined piece (18), and mounted again in this form. The attachment (17) can be manufactured of plastic or metal. The attachment (17) shown in the figure is a plastic component manufactured by injection molding. The abrasive stone (11) can be integrated with a prefabricated attachment (17) by a bayonet fixing and/or gluing, but it is also possible to place the stone (11) in the injection mold as an insert, and inject the attachment (17) onto the stone so as to manufacture it integrally with the stone. Whichever joining method is utilized, providing cooperating indents (19) and protrusions (20) on the surfaces of the stone (11) and the attachment (17) will improve the anchoring of the stone (11) in the latter. Alternatively only the indent (19) can be provided on either the stone (11) or the attachment (17), and the said fixation can be enhanced by allowing a bonding chemical used in the connection to fill this indent (19). The combined piece (18) which is obtained by joining the abrasive stone (11) with the attachment (17) in an inseparable manner is detachably fastened to the drum surface (12, 13, 14, 15) by different methods.

Figure 4-B shows top and bottom isometric views of the combined piece (18). As can be seen, at least one protrusion (21) with at least one lug (22) is provided on the bottom of the attachment (17). Furthermore, the attachment (17) possesses a lock pin tongue (25) extending axially from one longitudinal end. A locking pin (24) which is in the form of a protrusion and extending in the same direction with the said protrusions (21) is provided on this tongue (25). On the other longitudinal end of the attachment (17) there is provided a tongue housing (27) forming an indentation on the bottom thereof.

Figure 5 shows the assembly of the combined piece (18) to the drum (10). As can be seen, the perforated cylindrical surface (12) of the drum is provided with apertures (23) arranged intermittently. In the assembly position, the protrusions (21) on the bottom of the attachment (17) engage these apertures (23). At this stage, the locking pin (24) of the combined piece (18) abuts against the drum surface (12) and causes the lock pin tongue (25) to bend resiliently upwards. As the combined piece (18) is shifted forward in this position on the drum surface, the locking pin (24) aligns with a pin slot (26) formed on the drum surface (12) and enters into it (26). In this way, the locking of the combined piece (18) to the drum is accomplished. Detachment of the locking pin (24) from the pin slot (26) is prevented by means of the subsequent combined piece (18) mounted in such a way as to cover the lock pin tongue (25). As shown in Figure 4-C, when the subsequent combined piece (18) is being mounted, its tongue housing (27) provided on the bottom thereof sits on the lock pin tongue (25) of the previous combined piece (18). Hence, every new combined piece (18) mounted to the drum on the lock pin tongue (25) side of the previous one facilitates the fixing of the preceding combined piece (18). Since there is no subsequent combined piece to fix the lock pin tongue (25') of the last combined piece (18') of a row, the lock pin tongue (25') of the last combined piece (18') is fastened to the perforated drum surface (12) by means of conventional fasteners such as screws, rivets etc. passing through the fastening holes (28) provided thereon. Figure 4-D shows the last combined piece (18') of a row and its lock pin tongue (25'). Figure 6 depicts schematically the assembly of the combined piece (18) which is composed of an attachment (17) and an abrasive stone (11) in stick form and which is being mounted to the perforated cylindrical drum surface (12) starting from the rear-axle support shaft bearing surface (15) and proceeding forward.

The combined pieces (18) may comprise a single piece of abrasive stone (11) each as shown in Figures 4, 5 and 6, but they can also be provided in the form of multi- combined parts (31) where each having more than one piece of stone (11) fixed on a single attachment (29).

Figure 7-A is a bottom isometric view of such a multi-combined part (31). Figure 7-B shows a side isometric view thereof and 7-C shows the piece while it is being mounted onto the perforated drum surface. Figure 8 A through C presents the enlarged views for the purpose of clarity.

As it is clear from Figure 7 and 8, the multi-combined part (31) comprises again an attachment (29) which can be manufactured of plastic or metal and more than one piece of abrasive stone (11) joined inseparably therewith. The lock pin tongue (25') provided on both longitudinal ends of the attachment (29) comprises again a locking pin (24) and at least one, preferably two fastening holes (28). Assembly is again accomplished by engagement of the protrusion (21) of the attachment (29) and the lug (22) thereon in the apertures (23) provided on the drum surface (12) and insertion of the locking pins (24) arranged on both lock pin tongue (25') into the pin slot (26). Subsequently, the combined part (31) can be fastened to the perforated drum surface (12) by means of bolts (52) passing through the fastening holes (28) on the lock pin tongue (25') as shown in the figures. In this connection, in order to prevent the sharp terminal edges of the abrasive stones (11) from damaging the fabric, it is advantageous to cover the visible sharp-edged terminal ends of the first end the last stones by a protective cap (30) arranged on the attachment (29) piece of the multi piece combined part. While the plastic attachment is illustrated in Figures 7- 9, Figures 10, 11 and 12 show a metal attachment (29) made of stainless steel. As shown in the figures, pieces of abrasive stone (11) which are already glued to the attachment (29) are mounted to the drum together with the attachment as combined part (31). Assembly is again accomplished by engagement of the protrusion (21) of the attachment (29) and the lug (22) thereon in the apertures (23) provided on the drum surface (12) and then locking by being pushed forward while still in the apertures. As backward sliding of the combined part (31) is prevented by a suitable technique, it will be fixed on the drum surface (12). Abrasive stones can be disposed on the drum surface in a direction parallel or orthogonal to the rotation axis. When the surface onto which they are mounted in a direction orthogonal to the rotation axis is planar such as the paddle surfaces (13), there is no need to alter their form. However, when they are being mounted onto the cylindrical surface (12), having both the stones (11) and the attachment (29) in a concave form conforming to the curvature of the cylindrical drum surface (12) will ensure the adoption of the surfaces and facilitate the assembly on the cylindrical surface (12).

The attachment (17, 29) illustrated above as being plastic may also be used in metal form. A attachment (17, 29) manufactured from stainless metal and formed in a die either separately or together with the stone so as to hold the abrasive stone (11) can also fasten the abrasive stone to the drum surface.

In an alternative embodiment of the invention illustrated in Figures 13 through 19, stainless steel fastening profiles (32) which are mounted to the drum surface (12, 13, 14, 15) so as to be integral with the drum (10) are utilized instead of the detachable attachments (17, 29) outlined above. These profiles (32) are secured to the drum surfaces that the stones are to be attached. The assembly can be accomplished by directly welding the stainless profile (32) to the drum (10) as well as by means of bolts and rivets. The profiles (32) can be disposed side-by-side in series or as shown in Figures 2 and 3, they can be arranged on the front or rear surfaces (14, 15) at an angle with each other. Each row may comprise one or more than one profile (32). Rails of attachment profile (33) provided on the profiles (32) mounted in this manner secure the stones (34) on the drum surface by interlocking with the slots (35) arranged on the sides of the stone sticks (34). The profiles (32) into which the stones are disposed may have various widths in accordance with the size of the stones (34) used. The two ends of the fastening profile (32) are closed either by a permanently closed end (36) or with a removable cap (37) so as to prevent the detachment of the stones.

A sufficient space with respect to the size of the stone (34) should be provided on the side of the removable cap (37) to allow the abrasive stone (34) to be inserted into the profile (32) by sliding longitudinally. Since such available space is left on the side of the removable cap (37) for the profiles (32) mounted onto the front or rear surfaces (14, 15) of the drum, the stones (34) can easily be located in the profile (32) by simply removing the cap (37), inserting the stones and sliding longitudinally. Figure 15 illustrates this assembly method. Figure 15-A shows an exploded view of the

components, and B and C illustrate top and bottom isometric views of the assembled form. One free end of the profile (32) can be permanently closed (36). The abrasive stones (34) are placed inside the profile (32) from the end with the cap by removing the cap (37). The cap (37) can be secured in its place by fastening a countersunk head bolt (52) to a rivet nut (52-2) arranged on the bottom of the profile (32). The rivet nut (52-2) will form a bulge on the bottom of the profile (32). Since on the cylindrical drum surface (12) there can be a hole under the rivet nut (52-2), the profile (32) can be welded thereon directly with its bottom in contact with the drum surface (12). However, if it is not possible to perforate the front or rear surfaces (14, 15) of the drum, then it may be required to use an additional assembly plate (39) under the bottom of the profile (32) both to elevate the bottom of the profile (32) and to be able to weld it to the surface (14, 15).

However, when it comes to the profiles disposed on the cylindrical surface (12) or on the paddle surfaces (13) of the drum, there is not enough space left between the profiles (32) and the front/rear surfaces (14, 15) of the drum to cover the length of the stone (34) so that it can be inserted into the profile (32) by sliding longitudinally, thereby in that case the pieces of abrasive stone (34) are needed to be inserted into the profiles either laterally or from the top. Therefore the stones (34) are introduced into the profile (32) through an opening (38) which is formed on one side of the profile and dimensioned to permit the insertion of the stone as shown in Figure 16. At least one free end of these profiles (32) may be permanently closed (36). The stones (34) introduced through the insertion opening (38) are disposed in the profile (32) starting from the closed end (36) until the level of insertion opening (38). Insertion and locking of the last stone (34) in the profile (32) can be accomplished by various methods.

An exemplary embodiment, which is shown in Figure 16 is explained hereinafter. As the details are illustrated in Figure 16-A, the stones (34) are disposed in the profile (32) having a stone insertion opening (38) sequentially starting from the closed end (36). Before insertion of the last stone, the stone (34) positioned in the profile (32) next to the cap (37) is pulled out together with the cap (37) approximately by one half of its _. length. At this position, shown in Figure 16-B, the last stone (34) is inserted through the insertion opening (38). Subsequently, the stone (34) pulled out is pushed in its place together with the cap (37) and fixed by means of the bolt (52). In this final position, the stone insertion opening (38) lies in a region of the mating line (40) of two stones as depicted in Figure 16-C Thus, although the rail slots (35) of the mating stones are partially unoccupied in the region of the opening (38), the rails (33) engaging the slots (35) on two sides of the opening (38) accomplish securing of the both stones (34) to the profile (32).

In another exemplary attachment method in accordance with Figure 17 and 18, independent of whether the ends of the profile (32) are permanently closed (36) or open, the profile (32) may be placed in such a way that it abuts against the front/rear surfaces (14,15) of the drum so as to leave no gap there between. In such a case, a stone insertion opening (38) having a length greater than the length of the stone is formed on one side of the profile as shown in Figure 17-A, and an independent locking part (44) is employed to complement this portion of the rail (33). As shown in the figure, a second locking opening (49) is provided on the side opposing the stone insertion opening (38). The locking part (44) comprises a first tongue part (46) which, when the locking part (44) is placed to complement said stone insertion opening (38), engages the rail slots (35) of the stone (34) aligned with the opening (38). Since said first tongue part (46) is long enough to fully cover the stone insertion opening (38) and since said stone insertion opening (38) is longer than the stone length, said first tongue part (46) also partially engages the slots (35) of the neighbouring stones on the front and back. This arrangement can be seen more clearly in Figure 17-B. In this way, front and rear stones (34) secured in the profile (32) perform the locking of the last stone (34). Just after the last stone in the profile is locked, the locking part (44) has to be fixed. This is achieved by means of a second locking tongue (48) provided on the locking part (44). The second locking tongue (48) which is formed at a position facing the first tongue part (46) and preferentially with a shorter length is positioned so as to be accommodated in the aforementioned second locking opening (49) of the neighbouring profile (32) to be placed next (Figure 17-C) and thus it engages the rail slot (35) of the last stone (34) in the neighbouring profile (32). In this manner, assembly of each profile (32) ensures locking of the stones in the adjacent profile. On the other side, the locking part (44') of the last profile after which no adjacent profile is to be mounted on the side of the locking member, is fastened to the drum

detachably by means of a bolt (52) as shown in Figure 17-D.

Figure 19 illustrates exemplary alternative arrangements of the abrasive stone pieces (11, 34). These examples are not to be deemed limitative and the cross-section of the abrasive stone (11, 34) can be selected by those skilled in the art differently, such as circle, semi-circle, rectangle, triangle, elliptical and similar. In alternative embodiments, the cross-section may be constant or variable along the longitudinal axis of the stone. The ray slots (35) of the stone (34) can be arranged in alternative forms provided that the rail (33) of the profile can engage. Furthermore, it is also possible to form various cavities in the stones (11, 34) in order to reduce their weight so that the load exerted by the stones on the drum is decreased. As shown in Figure 19, these cavities may be in the form of one or more than one through/blind holes (41) or a hollow (42) provided in different positions of the stone, or in alternative shapes.

The components and the assembly methods illustrated above are exemplary embodiments disclosed due to their cost-effectiveness and ability to allow quick replacement of the stones when required.