Dust extraction attachment with adjustable cutting depth for the protective cover of an angle grinder

Abstract

The utility model relates to mechanical engineering, specifically to auxiliary devices for hand-held power tools. The technical result consists in enabling the adjustment of the cutting depth of a grinding or cutting wheel of an angle grinder. A dust extraction attachment for an angle grinder comprises a housing, a dust extraction pipe, a clamping unit, support rollers, and a mounting section. The housing comprises a dust collection screen, a working opening, and a slot formed in the dust collection screen. The mounting section is connected to the housing on one side by a clamping wing nut, and on the other side by an adjusting wing nut located in the slot of the dust collection screen. The mounting section comprises a support surface for the clamping unit and at least one positioning element. The support rollers are located in the lower part of the housing on the side of the working opening. 13 clauses, 3 figs.

Description

[0001] Field of technology to which the utility model belongs

[0002] The utility model relates to mechanical engineering, namely to additional devices for hand-held power tools, and can be used as part of angle grinders to adjust the cutting depth of a grinding or cutting wheel and remove dust from the working area of ​​the angle grinder.

[0003] Technology Level

[0004] A prior art discloses a device for limiting a cutting depth, which comprises a cutting depth guiding unit and a stopper unit. The stopper unit comprises an element movable relative to the cutting depth guiding unit along a guide path to limit the depth of penetration of the working tool into the workpiece. The description also discloses the ability to set the position of the element associated with limiting the cutting depth using a scale (see patent US9623583B2, published April 18, 2017).

[0005] The described design allows for the cutting depth to be adjusted by changing the position of the locking element relative to the guide assembly. However, this approach complicates the design, as the cutting depth setting function is implemented by a separate mechanism, not directly connected to the attachment seat and its position relative to the protective cover. When using a removable dust extraction attachment, a more efficient design is one in which the cutting depth is adjusted by changing the position of the attachment seat relative to the attachment body.

[0006] Also known from the prior art is a dust collection hood for an angle grinder with an adjustable mounting mechanism, which comprises a housing forming a dust collection chamber, a dust extraction port communicating with said chamber, an opening for the output shaft of the angle grinder, and a plurality of mounting brackets attached to the hood housing. The mounting brackets are movable relative to the hood housing, including through slots, to change their position around the output shaft of the angle grinder and mount the hood on the tool (see patent US11123839B2, published September 21, 2021).

[0007] The design of this analog is focused on aligning the mounting brackets with the angle grinder's mounting area and positioning the dust collection hood relative to the tool's output shaft. This adjustment allows the hood to be adapted to different angle grinders, but it does not provide the ability to adjust the cutting depth when cutting or chasing.

[0008] The closest technical solution to the claimed utility model is a device for forming horizontal linear cuts in curb sections or stone structures, which comprises a frame, guides on linear bearings, an angle grinder, one or more cutting discs, and a protective screen. The protective screen covers the cutting discs and may contain one or more rollers for controlling the cutting depth. In this solution, the cutting depth is adjusted by rotating the protective screen and locking it in the selected position via a control mechanism (see patent US11084185B2, published August 10, 2021).

[0009] This technical solution is closest to the claimed utility model, as it relates to a device that uses an angle grinder to cut building materials, incorporates a protective element in the cutting disc area, and utilizes rollers to control the cutting depth when cutting slots in the material. Analysis of the prototype shows that its design is intended for use within a more complex device with a frame and guides, designed for cutting slots in curb sections or other stone structures. Adjusting the cutting depth by rotating the protective screen and then locking it in place is feasible within the frame device; however, this design is less convenient for a compact, removable dust extraction attachment mounted directly to the standard protective guard of the angle grinder.Rotating the protective shield, as the primary adjustment element, can alter the spatial position of the dust collection zone, support elements, and attachment body relative to the working area of ​​the wheel, complicating stable tool guidance along the cutting line. Furthermore, the prototype is designed for use with an angle grinder mounted on a workpiece with guides, whereas manual guidance of the angle grinder along the cutting line requires a simpler and more compact adjustment performed directly on the dust extraction attachment. In this type of operation, it is essential not only to control the cutting depth but also to be able to quickly change and lock the position of the mounting area relative to the attachment body without reconfiguring the entire protective element or disturbing the position of the dust collection zone relative to the working wheel.

[0010] Disclosure of the essence of the utility model

[0011] Previous dust extraction attachments for angle grinders are primarily designed to remove dust from the work area and secure the attachment relative to the tool or its guard. However, when performing cutting, chasing, or other operations that involve plunging the grinding or cutting wheel into the material, not only dust removal is essential but also the ability to align the attachment's position with the desired cutting depth and the position of the working wheel. In conventional designs, changing the cutting depth either requires additional readjustment of the attachment's position or does not provide a reproducible setting of the attachment's position relative to the working wheel while maintaining its secure position on the guard. As a result, tool setup can be complicated, and the cutting depth during operation can be less consistent.

[0012] The technical objective of the claimed utility model is to develop a dust-extraction attachment for installation on a standard protective cover of an angle grinder, the design of which allows the position of the attachment to be adapted relative to the working wheel of the angle grinder to the required cutting conditions while maintaining the attachment's fixation on the protective cover.

[0013] The technical result achieved by the claimed utility model consists in providing the ability to adjust the cutting depth of a grinding or cutting wheel of an angle grinder by changing and fixing the position of the mounting area relative to the body of the dust extraction attachment.

[0014] The technical result is achieved using a dust extraction attachment with adjustable cutting depth for installation on a protective casing of an angle grinder, comprising a housing, a dust extraction pipe, a fixation unit, support rollers and a mounting section, characterized in that the housing contains a dust collecting screen, a working opening and a slot made in the dust collecting screen, wherein the mounting section is connected on one side to the housing by means of a clamping wing nut made with the possibility of fixing the mounting section relative to the housing, and on the other side is connected to an adjusting wing nut installed in the slot of the dust collecting screen with the possibility of moving along the said slot, wherein the position of the adjusting wing nut is connected to the position of the mounting section relative to the housing with the possibility of setting the cutting depth of the wheel of the angle grinder,the mounting section comprises a support platform for accommodating the locking unit and at least one positioning element configured to limit the displacement of the mounting section relative to the protective casing of the angle grinder, and the support rollers are located in the lower portion of the housing on the side of the working opening; the slot limits the movement of the adjusting wing nut and specifies the permissible range of movement of the mounting section relative to the housing; a graduation is made along the slot that corresponds to certain positions of the adjusting wing nut; the position of the adjusting wing nut relative to the graduation is associated with the angle of inclination of the mounting section relative to the housing; the clamping wing nut forms a locking connection of the mounting section with the housing, and the adjusting wing nut forms an adjusting connection of the mounting section with the dust collecting screen; the fixing unit comprises a threaded stud with a clamping portion of the stud,a manual clamp and a rivet with an internal thread; the clamping portion of the stud is made in the form of a tip, a support heel, a pad or other contact element that ensures the transmission of the clamping force to the protective cover of the angle grinder; the positioning element is made in the form of a stop edge, a locking window, a mounting slot, a protrusion or a combination thereof; each support roller is mounted for rotation on an axis; the support rollers are arranged so as to limit the immersion depth of the grinding or cutting wheel in the material being processed; contains two coaxial support rollers located next to the dust collecting window; contains two coaxial support rollers located next to the dust collecting window, and one support roller located on the opposite side of the housing from the side of the working opening; contains two coaxial support rollers located next to the dust collecting window, and two coaxial support rollers,located on the opposite side of the housing on different sides of the dust collecting screen; the support rollers are replaceable.

[0015] Using the dust extraction attachment provides convenient and predictable guidance of the angle grinder along the cutting line, allows you to pre-set the required cutting depth, reduces the likelihood of the wheel uncontrollably penetrating into the material, and reduces the spread of dust in the work area by connecting an external suction device.

[0016] Brief description of drawings

[0017] Fig. 1 shows a general view of the claimed dust extraction attachment with cutting depth adjustment for the protective cover of an angle grinder in isometric view.

[0018] Fig. 2 shows the front view of the claimed dust extraction nozzle.

[0019] Fig. 3 shows a reverse view of the claimed dust extraction nozzle.

[0020] The figures indicate:

[0021] 1 - body;

[0022] 2 - dust removal pipe;

[0023] 3 - fixing unit;

[0024] 4 - support roller;

[0025] 5 - landing site;

[0026] 6 - dust collection screen;

[0027] 7 - section of the casing connection with the dust extraction pipe;

[0028] 8 - working opening;

[0029] 9 - dust collection window;

[0030] 10 - slot;

[0031] 11 - graduation;

[0032] 12 - adjusting wing nut;

[0033] 13 - support platform;

[0034] 14 - positioning element;

[0035] 15 - pressure wing nut;

[0036] 16 - threaded stud;

[0037] 17 - clamping part of the stud;

[0038] 18 - manual lock;

[0039] 19 - rivet with internal thread;

[0040] 20 - dust removal channel;

[0041] 21 - receiving section of dust extraction pipe;

[0042] 22 - support roller axis;

[0043] 23 - support roller holder.

[0044] Implementation of a utility model

[0045] An embodiment of the claimed utility model is a dust extraction attachment with adjustable cutting depth for installation on the guard of an angle grinder. The dust extraction attachment is designed as a removable device that is installed on the standard guard of the angle grinder and secured relative to it. The guard, grinding or cutting wheel, suction hose, suction device, and work surface are not included in the claimed dust extraction attachment and are not shown in the figures.

[0046] The dust-extraction nozzle comprises a housing 1, a dust-extraction pipe 2, a fixing unit 3, support rollers 4 and a seat 5 made in the form of a separate part installed with the possibility of movement relative to the housing 1.

[0047] Housing 1 forms the supporting part of the dust-extraction attachment. Housing 1 comprises dust-collecting screen 6, section 7 for connecting housing 1 with dust-extraction pipe 2, working opening 8, dust-collecting window 9, and also slot 10 formed in dust-collecting screen 6. In the area of ​​slot 10 on dust-collecting screen 6, graduation 11 is made, intended for visual determination of the position of adjusting wing nut 12 and the corresponding position of seat 5 relative to housing 1.

[0048] Dust collection screen 6 is part of housing 1, designed to be positioned on the end face of the grinding or cutting wheel of an angle grinder. Working opening 8 is located in the lower part of housing 1 and allows the cutting edge of the grinding or cutting wheel to interact with the workpiece when the dust extraction attachment is installed.

[0049] Mounting section 5 is designed to mate the dust extraction attachment with the standard protective cover of the angle grinder. Mounting section 5 is designed as a separate part movable relative to housing 1 and comprises a support pad 13 for accommodating locking unit 3, as well as at least one positioning element 14 configured to limit the displacement of mounting section 5 relative to the protective cover of the angle grinder. Positioning element 14 may be designed, for example, in the form of a stop edge, a locking window, a mounting slot, a protrusion, or a combination thereof.The number of positioning elements 14 may be different, while the implementation of one positioning element 14 is sufficient to limit the displacement of the landing section 5 relative to the protective casing, and an increase in the number of positioning elements 14 does not change the achievement of the declared technical result, since the possibility of adjusting the cutting depth is ensured by changing and fixing the position of the landing section 5 relative to the body 1.

[0050] The mounting section 5 is connected on one side to the housing 1 by means of a clamping wing nut 15. The clamping wing nut 15 is configured to fix the mounting section 5 relative to the housing 1 in a selected position. On the other side, the mounting section 5 is connected to an adjusting wing nut 12 installed in a slot 10 of the dust collecting screen 6. The adjusting wing nut 12 is configured to move along the slot 10 when the position of the mounting section 5 relative to the housing 1 changes.

[0051] The slot 10 limits the movement of the adjusting wing nut 12 and thereby sets the permissible range of movement of the mounting section 5 relative to the housing 1. The graduation 11 is made along the slot 10 or near it and corresponds to certain positions of the adjusting wing nut 12. The position of the adjusting wing nut 12 relative to the graduation 11 is associated with the angle of inclination of the mounting section 5 relative to the housing 1, as a result of which the position of the declared dust extraction nozzle is adjusted relative to the standard protective cover of the angle grinder and the cutting depth is set with a grinding or cutting wheel.

[0052] In one embodiment, the pressure wing nut 15 forms a locking connection of the seating section 5 with the housing 1, and the adjusting wing nut 12 forms an adjusting connection of the seating section 5 with the dust-collecting screen 6. When the pressure wing nut 15 and the adjusting wing nut 12 are loosened, the seating section 5 can be moved relative to the housing 1 within the limits specified by the slot 10. After the adjusting wing nut 12 is installed in the required position according to the graduation 11, the pressure wing nut 15 and the adjusting wing nut 12 are tightened, fixing the seating section 5 relative to the housing 1.

[0053] When changing the position of the seat section 5 relative to the body 1, the relative position of the body 1, the working opening 8 and the support rollers 4 relative to the grinding or cutting wheel of the angle grinder changes, as a result of which the amount of protrusion or projection of the cutting part of the said wheel relative to the support zone of the attachment on the surface being processed is adjusted, which makes it possible to set the required cutting depth.

[0054] The fixation unit 3 is located on the support platform 13 of the seat 5. The fixation unit 3 comprises a threaded stud 16 with a stud clamping portion 17, a manual clamp 18 and a rivet 19 with an internal thread. The rivet 19 is installed in the support platform 13 and is secured relative to the seat 5. The threaded stud 16 is installed so as to be capable of threaded interaction with the rivet 19 and axial movement relative to the seat 5 when the threaded stud 16 rotates.

[0055] Manual clamp 18 is connected to threaded stud 16 and is designed to be manually rotated without the use of a separate tool. Stud clamping portion 17 is located on the portion of threaded stud 16 facing the standard protective cover and is designed to contact said protective cover. Stud clamping portion 17 may be implemented as a tip, support heel, pad, or other contact element that ensures the transfer of clamping force to the protective cover of the angle grinder.

[0056] When the manual lock 18 rotates, the threaded stud 16 moves relative to the rivet 19, as a result of which the clamping part of the stud 17 creates a clamping force that holds the seating section 5 and the body 1 associated with it relative to the protective cover of the angle grinder.

[0057] The dust-extraction pipe 2 is connected to the housing 1 in the area of ​​the dust-receiving window 9. The dust-extraction pipe 2 contains a dust-extraction channel 20 and a receiving section 21 located on the side of the dust-receiving window 9. The dust-receiving window 9 is formed in the area 7 of the connection of the housing 1 with the dust-extraction pipe 2 and ensures communication between the dust-receiving area of ​​the housing 1 and the dust-extraction channel 20.

[0058] Support rollers 4 are located in the lower part of the housing 1 on the side of the working opening 8. Each support roller 4 is mounted with the possibility of rotation on an axis 22. Depending on the embodiment, the attachment may contain one common or several axes 22 on which the corresponding support rollers 4 are located. The axis 22 of the support roller 4 can be mounted directly on the housing 1 or in the support roller holder 23 connected to the housing 1.

[0059] The number and arrangement of the support rollers 4 may be different. In one embodiment, the dust-extraction nozzle contains two coaxial support rollers 4 located near the dust-collecting window 9. In another embodiment, the dust-extraction nozzle contains two coaxial support rollers 4 located near the dust-collecting window 9, and one support roller 4 located on the opposite side of the housing 1 from the side of the working opening 8. In yet another embodiment, the dust-extraction nozzle contains two coaxial support rollers 4 located near the dust-collecting window 9, and two coaxial support rollers 4 located on the opposite side of the housing 1 on different sides of the dust-collecting screen 6. If there are several groups of support rollers 4, each group can be placed on the corresponding axis 22.

[0060] Changing the number of support rollers 4 does not affect the achievement of the stated technical result, provided that their location is maintained with the possibility of contact with the surface being processed, since the limitation of the immersion depth of the grinding or cutting wheel is ensured by the very function of supporting the body 1 on the surface being processed through the support rollers 4, and not by the specific number of said rollers.

[0061] Support rollers 4 are designed to contact the workpiece during operation of the angle grinder. The material of support rollers 4 can be selected based on the type of workpiece and operating conditions. Support rollers 4 can be made of plastic, a high-rigidity polymer, rubber, an elastomer, or another material suitable for movement over the workpiece. Support rollers 4 are replaceable, including for selecting rollers for different workpiece materials or for replacement in the event of wear or repair of the dust extraction attachment.

[0062] The housing 1, the dust extraction pipe 2, the elements of the fixation unit 3, the support rollers 4, the seat 5, the adjusting wing nut 12, the support platform 13, the positioning element 14, the pressure wing nut 15, the axles 22 and the holders 23 of the support rollers 4 can be made of metal, plastic, polymer or composite material or of a combination of the specified materials, taking into account the required rigidity, wear resistance, weight and operating conditions of the dust extraction nozzle.

[0063] The parts and components of the dust extraction nozzle may be joined together by welding, soldering, riveting, threading, adhesive bonding, pressing, snapping, or other detachable or permanent connections that ensure the required strength and operability. Elements that do not require relative movement during nozzle operation may be manufactured as a single piece.

[0064] In the working position, mounting section 5 is mated with the standard protective cover of the angle grinder. Positioning element 14 limits the displacement of mounting section 5 relative to the protective cover, and locking unit 3 presses mounting section 5 against the protective cover through the axial movement of threaded stud 16 and the contact action of the clamping portion of stud 17 on the protective cover. Housing 1 is held relative to mounting section 5 by adjusting wing nut 12 and clamping wing nut 15.

[0065] Before using the attachment, set the desired cutting depth by adjusting the position of the mounting section 5 relative to the housing 1. To do this, loosen the wing nuts 12 and 15, then move the adjusting wing nut 12 along the slot 10 to a position corresponding to the desired value on the graduation 11. Moving the adjusting wing nut 12 changes the angle of the mounting section 5 relative to the housing 1, which changes the position of the working opening 8 and the support rollers 4 relative to the grinding or cutting wheel and, thereby, the projection of the cutting portion of the wheel. This sets the cutting depth. After selecting the desired position, tighten the wing nuts 12 and 15, fixing the mounting section 5 relative to the housing 1.

[0066] When installing the dust extraction attachment, mounting area 5 is aligned with the corresponding area of ​​the standard protective casing. After mounting area 5 is preliminarily positioned, manual clamp 18 is rotated. Threaded stud 16 interacts with rivet 19 and moves relative to mounting area 5. The clamping portion of stud 17 acts on the protective casing and creates a clamping force, due to which mounting area 5 is held on the protective casing, and housing 1 is held relative to the protective casing through mounting area 5.

[0067] When the angle grinder is operating, support rollers 4 contact the workpiece and rotate relative to axes 22 as the tool moves along the cutting line. This contact provides additional support to the body 1 against the workpiece. The selected position of seat 5 relative to body 1, secured by wing nuts 12 and 15, together with support rollers 4, limits the depth of the grinding or cutting wheel into the workpiece and facilitates guidance of the angle grinder in the desired plane.

[0068] Dust and processing products generated in the working area, under the action of the vacuum created by the external aspiration device, enter through the dust-receiving window 9 into the dust-extraction channel 20 and are discharged through the receiving section 21 of the dust-extraction pipe 2 to the external aspiration device.

[0069] Thus, by implementing the mounting section 5 as a separate part movable relative to the housing 1, connected to the housing 1 by means of a clamping wing nut 15 and an adjusting wing nut 12 installed in a slot 10 with a graduation 11, it is possible to adjust the position of the mounting section 5 relative to the housing 1 and set the cutting depth. Due to the joint action of the mounting section 5, the positioning element 14, the locking unit 3 and the support rollers 4, preliminary positioning of the declared attachment relative to the standard protective cover, forceful fixation of the attachment on the protective cover, additional support of the housing 1 on the work surface and limitation of the immersion depth of the grinding or cutting wheel into the material are ensured. This increases the stability of the placement of the dust extraction attachment, reduces the likelihood of its displacement during operation, increases the stability of the cutting depth and facilitates the guidance of the angle grinder along the cutting line.

Claims

1. A dust extraction attachment with adjustable cutting depth for mounting on a protective casing of an angle grinder, comprising a housing, a dust extraction pipe, a fixing unit, support rollers and a mounting section, characterized in that the housing comprises a dust collecting screen, a working opening and a slot made in the dust collecting screen, wherein the mounting section is connected on one side to the housing by means of a clamping wing nut made with the possibility of fixing the mounting section relative to the housing, and on the other side is connected to an adjusting wing nut installed in the slot of the dust collecting screen with the possibility of moving along the said slot, wherein the position of the adjusting wing nut is connected to the position of the mounting section relative to the housing with the possibility of setting the cutting depth of the wheel of the angle grinder, the mounting section comprises a support platform for accommodating the fixing unit and at least one positioning element,designed with the ability to limit the displacement of the seating area relative to the protective cover of the angle grinder, and the support rollers are located in the lower part of the housing on the side of the working opening.

2. A dust-extraction nozzle according to paragraph 1, characterized in that the slot limits the movement of the adjusting wing nut and sets the permissible range of movement of the seating section relative to the housing.

2. A dust-extraction nozzle according to paragraph 1, characterized in that the slot limits the movement of the adjusting wing nut and sets the permissible range of movement of the seating section relative to the housing.

3. A dust-extracting nozzle according to item 1, characterized in that along the slot 3. A dust extraction nozzle according to paragraph 1, characterized in that a graduation is made along the slot, which corresponds to certain positions of the adjusting knob.

4. A dust-extraction nozzle according to paragraph 1, characterized in that the position of the adjusting knob relative to the graduation is associated with the angle of inclination of the seating section relative to the housing.

4. A dust-extraction nozzle according to paragraph 1, characterized in that the position of the adjusting knob relative to the graduation is associated with the angle of inclination of the seating section relative to the housing.

5. A dust-extraction nozzle according to paragraph 1, characterized in that the pressure wing nut forms a locking connection of the seating section with the housing, and the adjusting wing nut forms an adjusting connection of the seating section with the dust-collecting screen.

5. A dust-extraction nozzle according to paragraph 1, characterized in that the pressure wing nut forms a locking connection of the seating section with the housing, and the adjusting wing nut forms an adjusting connection of the seating section with the dust-collecting screen.

6. A dust-extraction nozzle according to paragraph 1, characterized in that the fixing unit contains a threaded stud with a clamping part of the stud, a manual lock and a rivet with an internal thread.

6. A dust-extraction nozzle according to paragraph 1, characterized in that the fixing unit contains a threaded stud with a clamping part of the stud, a manual lock and a rivet with an internal thread.

7. A dust extraction attachment according to paragraph 6, characterized in that the clamping portion of the stud is made in the form of a tip, a support heel, a pad, or other contact element that ensures the transfer of the clamping force to the protective cover of the angle grinder.

7. A dust extraction attachment according to paragraph 6, characterized in that the clamping portion of the stud is made in the form of a tip, a support heel, a pad, or other contact element that ensures the transfer of the clamping force to the protective cover of the angle grinder.

8. A dust-extracting nozzle according to item 1, characterized in that the positioning element is made in the form of a stop edge, a fixing window, a mounting slot, a height 8. A dust-extraction nozzle according to paragraph 1, characterized in that the positioning element is made in the form of a stop edge, a locking window, a mounting slot, a protrusion, or a combination thereof.

9. A dust-extraction nozzle according to paragraph 1, characterized in that each support roller is mounted with the possibility of rotation on an axis.

9. A dust-extraction nozzle according to paragraph 1, characterized in that each support roller is mounted with the possibility of rotation on an axis.

10. A dust extraction attachment according to paragraph 1, characterized in that the support rollers are arranged to limit the depth of immersion of the grinding or cutting wheel into the material being processed.

10. A dust extraction attachment according to paragraph 1, characterized in that the support rollers are arranged to limit the depth of immersion of the grinding or cutting wheel into the material being processed.

11. A dust-extraction nozzle according to claim 1, characterized in that it contains two coaxial support rollers located next to the dust-collecting window.

11. A dust-extraction nozzle according to claim 1, characterized in that it contains two coaxial support rollers located next to the dust-collecting window.

12. A dust-extraction nozzle according to paragraph 1, characterized in that it contains two coaxial support rollers located next to the dust-collecting window, and one support roller located on the opposite side of the housing from the side of the working opening.

12. A dust-extraction nozzle according to paragraph 1, characterized in that it contains two coaxial support rollers located next to the dust-collecting window, and one support roller located on the opposite side of the housing from the side of the working opening.

13. A dust-extraction nozzle according to paragraph 1, characterized in that it contains two coaxial support rollers located next to the dust-collecting window, and two coaxial support rollers located on the opposite side of the housing on different sides of the dust-collecting screen.

13. A dust-extraction nozzle according to paragraph 1, characterized in that it contains two coaxial support rollers located next to the dust-collecting window, and two coaxial support rollers located on the opposite side of the housing on different sides of the dust-collecting screen.

14. A dust-extraction nozzle according to paragraph 1, characterized in that the support rollers are replaceable.

14. A dust-extraction nozzle according to paragraph 1, characterized in that the support rollers are replaceable.

Images