Patent Publication Number: US-2016229028-A1

Title: Fast Mountable Tool

Description:
FIELD OF THE INVENTION 
     The present invention generally relates to a fast, efficient way to mount or dismount a tool having a cylindrical cavity to/from a drive shaft. More specifically, the present invention relates to an efficient and accurate way to connect a tool having a cylindrical cavity to a drive shaft without the need for additional mechanical aids. These tools with a cylindrical shaped cavity are for example suitable for sanding or grinding or polishing. 
     BACKGROUND OF THE INVENTION 
     The present invention is mainly situated in the metal industry, more specifically in the stainless steel industry. The invention is related to hand-held or portable machines whereupon a tool with a cylindrical cavity can be mounted. In particular applications, this tool with a cylindrical cavity is a sanding wheel or a grinding wheel, further herein indicated as “sanding/grinding wheel”. One speaks of sanding wheels or grinding wheels, also called polishing wheels or finishing wheels, although other names may also be used for this type of wheels. The driving of the wheels is typically performed by driving a drive shaft in a portable polishing machine. This polishing machine has a spindle blocking mechanism or a spindle lock. 
     The invention is mainly aimed at fitting the sanding/grinding wheels on their drive shaft. In the prior art, various types of drive methods for sanding or grinding wheels are known. 
     In a first prior art method, the drive shaft contains one, two, or four keyways (also known as key-grooves or key-seatings). An adapter with abrasive (e.g. sanding or grinding) material is slid over this shaft and is secured to the drive shaft by means of a bolt and a washer. This type of mounting implies that there is a protruding element which projects beyond the sanding/grinding wheel, i.e. the fixing bolt extends beyond the sanding/grinding wheel. This projecting part will typically have a disturbing effect in certain applications, especially when one has to sand or grind along 90° upright sides in the longitudinal direction. This requires full attention of the operator in order not to cause damage to these upright sides. If the co-rotating fixing bolt contacts the stainless steel during the sanding or grinding operation, this can lead to damage of the stainless steel. 
     An additional drawback of this attachment method is the relatively high changeover time for replacing the sanding/grinding wheels. In particular, each time one has to loosen and remove the fixing bolt, dismount the sanding/grinding wheel, mount another type of sanding/grinding wheel, and then mount and tighten the fixing bolt to secure the sanding/grinding wheel. 
     With this attachment method, the drive shaft diameter and the inner diameter of the adapter may be different. This is dependent on the manufacturer of the shaft and the manufacturer of the adapter. Often they are not matched as regards the exact diameters. This causes an imbalance and vibration of the sanding/grinding wheel, and results in a cloud-like appearance on the stainless steel. This cloud-like appearance can be seen in the axial sanding/grinding direction. Clearances of 0.5 mm between the drive shaft and the adapter have been encountered. 
     Another mounting method is the moulding of a non-ferrous screw thread in the sanding/grinding wheel. This moulded screw thread fits perfectly on the polishing machine. Also, tapping an internal screw thread in the moulded resin core of the sanding/grinding wheel is a possibility. The tapped screw thread fits directly onto a corresponding external screw thread of the polishing machine. For both techniques, the sanding/grinding wheels are manually secured on the polishing machine. Again, the changeover time required for replacing the sanding/grinding wheels is inherently relatively high. 
     A third known drive technology is based on centrifugal force. Here, an expansion clamping sleeve is mounted in a matching sanding/grinding wheel. This expansion clamping sleeve replaces the adapter. During operation of the polishing machine, the clamping sleeve expands so that the sanding/grinding wheel is blocked and is driven. 
     A possible embodiment hereof is described in U.S. 2007/0259611. 
     However, there remains a need for an efficient system and an efficient method for mounting/dismounting a tool having a cylindrical cavity to/from a drive shaft, for example sanding machines or grinding machines in the metal industry, in particular portable sanding machines or portable grinding machines. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a system and a method for efficiently and accurately mounting a tool having a cylindrical cavity on a mounting system. 
     It is an advantage of embodiments of the present invention that the time required to changeover the tool having a cylindrical cavity is substantially reduced. 
     In most solutions in the prior art, each time one has to loosen a fixing bolt, dismount the tool with cylindrical-shaped cavity, mount a different type of tool with a cylindrical cavity, and then re-secure the fixing bolt in order to change the tool with cylindrical cavity. 
     It is an advantage of embodiments of the present invention that the tool with cylindrical cavity can be changed without the need for additional auxiliary tools. This reduces the changeover time considerably. A changeover time reduction of 70% can thus be achieved. 
     It is an advantage of embodiments of the present invention that the mounted tool with cylindrical cavity, when driven by the drive shaft, is less subject to vibrations. The vibration reduction is achieved inter alia by making use of a spring or a compression spring mounted on the drive shaft. 
     It is an advantage of embodiments of the present invention that the clearance between the adapter and the drive shaft is small or even minimal. This clearance can be smaller than 0.2 mm. As a result, the vibrations on the tool with cylindrical cavity are avoided or are kept to a minimum. As a result, in the case of sanding or grinding, a more beautiful and more uniform sanding or grinding finish is obtained. 
     It is an advantage of embodiments of the present invention that no projecting object, such as a bolt, is necessary to attach the adapter on the drive shaft. Such protruding object would have a disturbing effect in certain applications and especially when one has to sand/grind in the longitudinal direction along 90° upright sides. This requires full attention of the operator in order not to cause damage to this upright side. When the co-rotating fixing bolt touches the material to be processed, this may lead to damage of this material. Due to the absence of this projecting object, it is possible to sand/grind closer to the upright side. 
     It is an advantage of embodiments of the present invention that the adapter can be used in a universal way for different tools having a cylindrical cavity. Only a single type or model of adapter is required. This adapter is adjustable. The dimensions of the drive shaft and of the adapter can be adjusted depending on the type of tool with cylindrical cavity that needs to be driven. 
     The above object is achieved by an apparatus, device and/or method according to the present invention. 
     The present invention is related to a mounting system for mounting a tool, the mounting system comprising:—a drive shaft, the drive shaft comprising a shaft with at least one key-zone (e.g. in the form of keyway or key-groove or key slot) in the axial direction on the outside of the shaft, and at least one key present in the at least one key-zone, and a collar located at an end of the drive shaft for positioning a spring,—a spring for introducing pressure between the drive shaft and an adapter when the drive shaft is positioned in the adapter, and—an adapter with a seat for accommodating the drive shaft, the seat comprising: at least one keyway adapted to allow sliding of the drive shaft with the key into the adapter, each keyway having a recess for each key-zone (of the drive shaft) for allowing the drive shaft to be rotated relative to the adapter after the drive shaft is slid into the adapter in such a way that the spring is under pressure between the collar of the drive shaft and a surface of the adapter, whereby the recess comprises at least one blocking element—also called shoulder—for blocking the at least one key when the drive shaft is rotated in the keyway, so that, when the drive shaft is mounted in the adapter, the drive shaft can transmit a moment of torsion to the adapter. 
     The key can be separate from the shaft, but is mountable in the at least one key-zone. Alternatively, the key may be fixedly mounted on the shaft. 
     The adapter may have an elongated shape with a substantially polygonal cross section, for example a substantially hexagonal cross section. The inner diameter of the seat may correspond with the outer diameter of the shaft. The inner diameter of the seat may be slightly larger than the outer diameter of the shaft to facilitate easier mounting. 
     The spring may be a compression spring. It is an advantage of embodiments of the present invention that a compression spring is used, because it only requires about ⅕ (or 20%) of the width compared to conventional wire springs. This makes the invention convenient for the user and has as a result that the width of the drive shaft is substantially the same or even slightly less than the width of keyway drive shafts known today for the same width of the tool. 
     The tool may comprise abrasive material, e.g. sanding or grinding material. The tool can be, for example, a sanding wheel or a grinding wheel. It is an advantage of embodiments of the present invention that a more beautiful and more uniform sanding or grinding appearance is obtained. It is an advantage of embodiments of the present invention that it allows to sand or grind with a reduced risk of errors. 
     The outer circumference of a cross section of the adapter may have a substantially polygonal cross-section, with at least three corners, whereby the sides of the polygonal cross-section may be concave and/or wherein the corners may be flattened. The adapter can thus have press faces corresponding to the flattened corners of the cross section, forming flattened edges along the axial direction of the adapter, and concave surfaces corresponding to the concave sides along the axial direction of the adapter. It is an advantage of embodiments of the present invention that various attachment techniques of the adapter in the tool (or machine) are possible. Due to the concave shape of the various surfaces, the attachment surface of the adapter can be increased, for example in the case of glueing. Because of this, the force uptake of the adapter is increased (e.g. much higher) and slippage of the adapter relative to the tool with cylindrical cavity is eliminated. The press faces provide an excellent possibility of pressing the adapter into the hard core of a tool. 
     The drive shaft may have a drive zone for connecting the drive shaft to a motor system for introducing a rotary motion to the tool during normal operation, after assembly. The drive zone may have a screw thread, e.g. an M14 female, or a ⅝″ screw thread, or can be mounted by means of a pin insertion. It is an advantage of embodiments of the present invention that the drive shaft is compatible with existing motor systems. Such motor systems may be hand-held or portable polishing machines and sanding machines and grinding machines. 
     An upper side and an underside of the adapter may have a complementary shape so that several similar adapters can be mounted contiguously on one another. It is an advantage that various adapters can be mounted contiguously on one another in the tool, whereby the various adapters are mounted such that they have the same shaft, that they touch one another, and that the keyway slots are in line with each other, and wherein the length of the drive shaft is adjusted in accordance with the number of adapters and the corresponding width of the whole. 
     It is an advantage of embodiments of the present invention that tools with a different width can be mounted by making use of one or more mounting systems or a single mounting system having multiple adapters and a longer drive shaft. The width of an adapter may vary for example between 20 mm and 300 mm, preferably between 30 mm and 100 mm. Several adapters, for example, two, three, four or more adapters may be provided contiguously to one another for emulating a single adapter having a width (in the axial direction) equal to the sum of the individual widths. 
     An adapter may have a male connector on one side and a female connector on the other side, so that when the male connector of a first adapter is mounted to the female connector of a second adapter, the two adapters nicely connect with each other. It is an advantage of some embodiments of the present invention that the connection between two contiguously mounted adapters is such that, for example, infiltration of for example an adhesive from the exterior to the interior of the adapter is avoided. 
     In an adapter there may be two (e.g. diametrically) opposing keyways, and in the drive shaft there may be two (e.g. diametrically) opposing key-zones. It is an advantage of embodiments of the present invention that the presence of two diametrically opposing keys per adapter ensures an optimum connection and greatly reduces the risk of vibration. 
     At the end of the drive shaft, opposite the end of the drive shaft with the collar, a quick-change connection may be provided which allows that a soft material, e.g. a felt, is mounted against the tool after the adapter is mounted on the drive shaft. 
     It is an advantage of embodiments of the present invention that a soft material, for example felt, can be mounted so that the side of the tool with cylindrical cavity (e.g. sanding/grinding wheel) becomes “non-abrasive”. In this way, besides eliminating the co-rotating bolt, also the abrasive effect of the side of the sanding/grinding wheel can be eliminated. In an exemplary embodiment of the present invention, the thickness of this felt is 3 mm. 
     At the end of the drive shaft opposite the end with the collar, a connection element may be provided for connecting the drive shaft to a tool via a threaded connection. It is an advantage of embodiments of the present invention that known sanding/grinding wheels can now also be connected to the drive shaft. In this way, it is possible to mount keyway wheels available on the market, by means of a bolt and washer. In this way the drive shaft becomes more universal, so that the drive shaft is also suited to mount existing sanding/grinding wheels with a continuous keyway. 
     The blocking element may be a radius seat in which and end of the key fits, in other words, that has a shape complementary to said end of the key. It is an advantage of embodiments of the present invention that only a very slight force needs to be applied in order to click the key in or out of the radius seat. 
     The adapter may include a marking that indicates which side of the adapter has to be slid over the drive shaft first (or formulated otherwise, on which side of the adapter the drive shaft is to be inserted), and/or in which direction the adapter has to be rotated relative to the drive shaft to rotate the key up to the recess. It is an advantage of embodiments of the present invention that clear markings indicate how the mounting of the adapter on the drive shaft needs to be performed. 
     The present invention also relates to an adapter for mounting a tool, the adapter being for use with a drive shaft having at least one key-zone arranged in the axial direction on the outside of the shaft, at least one key in the at least one key-zone, and a collar for positioning a spring, and for use with a spring for introducing a pressure between the drive shaft and the adapter after mounting, the adapter comprising a seat for accommodating the drive shaft, the seat comprising a keyway adapted to allow the drive shaft with at least one key to be inserted (e.g. slid) into the adapter, each keyway having a recess for each key-zone (of the drive shaft) for allowing the drive shaft to be rotated relative to the adapter after the drive shaft is slid into the adapter in such a way that the spring is under pressure between the collar of the drive shaft and a surface of the adapter, the recess comprising a blocking element—also called shoulder—for blocking the key when the drive shaft is rotated in the keyway, so that, when the drive shaft is mounted in the adapter, the drive shaft can transmit a moment of torsion to the adapter. 
     The outer contour of a cross section of the adapter may have a polygon-like shape, with at least three corners, the sides of the polygon-like shape being concave and/or the corners being flattened. 
     A top side and a bottom side of the adapter may have a complementary shape so that several similar adapters can be mounted contiguously to one another. 
     The adapter may have a male connector on one side and a female connector on the other side, so that, when the male connector of a first adapter is mounted to the female connector of a second adapter, the two adapters are contiguous to each other. The adapter may have two diametrically opposing keyways. The blocking element may be a radius seat in which an end of a key fits. 
     The adapter may include a marking that indicates which side has to slide over the drive shaft first and/or in which direction the adapter has to be rotated relative to the drive shaft in order to rotate the key up to the recess. 
     The present invention also relates to a tool, wherein the tool comprises an adapter as described here above. The adapter may be glued and/or pressed in a cavity of the tool, or the adapter may be moulded in a central cavity of the tool. It is an advantage of embodiments of the present invention that by providing a rigid (albeit detachable) connection between the adapter and the tool, the amount of vibration is reduced. In addition, the adapter fits perfectly with the drive shaft, which is not the case for the prior art where different types of tools each have their own adapter, which are not necessarily tuned to the drive shaft as far as their diameter is concerned. For example, because the manufacturer of the drive shaft and the manufacturer of the adapter are different. The fact that the prior art adapter and drive shaft are not perfectly matched to each other causes an imbalance and vibration on the tool with cylindrical cavity (e.g. sanding/grinding wheel). This can, in the case of a sanding/grinding application on stainless steel, lead to a cloud-like appearance on the stainless steel. This cloud-like appearance can be seen in the axial sanding/grinding direction. Clearances of 0.5 mm between the drive shaft and the adapter have been encountered in the prior art. 
     The tool of the present invention can consist of a group of smaller tools, each with a mounted or moulded adapter and positioned contiguous to each other, wherein the group of tools is mounted on a drive shaft adapted in length for driving the combination of adapters. It is an advantage of embodiments of the present invention that the tools with cylindrical cavity can be assembled or combined in the width direction to obtain the desired width. For example, if a tool with a cylindrical cavity (e.g. a sanding/grinding wheel) of 150 mm is required, this can be realized by making a combination on a drive shaft of a first wheel of 100 mm and a second wheel of 50 mm. 
     In another aspect, the present invention also provides a method for mounting a tool having a cylindrical cavity on a shaft of a motor system, the method comprising:—mounting a drive shaft on the axis of the motor system, the drive shaft comprising: a shaft with at least one key-zone arranged in the axial direction on the outside of the shaft, with at least one key mounted in the at least one key-zone, and at an end of the shaft a spring positioned against a collar of the shaft;—sliding the tool having a cylindrical cavity over the drive shaft, whereby an adapter is fitted in the tool, the adapter having a seat comprising at least one keyway so that the drive shaft with mounted key can be slid in the adapter, with in each keyway for each key-zone a recess which allows the drive shaft to be rotated relative to the adapter when the driving shaft is inserted so deep into the adapter that the spring is under pressure, and whereby the recess has a blocking element—for instance a shoulder—behind which the mounted key blocks, after the drive shaft has been rotated;—blocking the shaft of the motor system;—pushing the tool against the spring using a small force so that the spring is pressed in the tool by the adapter;—rotating the tool until the at least one key encounters the recess;—releasing the tool, so that, when the drive shaft is mounted in the adapter, the drive shaft can transmit a moment of torsion to the adapter. 
     It is an advantage of embodiments of the present invention that the mounting of the tool having a cylindrical cavity on a motor system can be accomplished without additional mechanical aids. 
     The present invention also relates to a method for dismounting a tool from a shaft of a motor system, the method comprising:—blocking the shaft of the motor system whereupon a drive shaft is mounted, the drive shaft comprising: a shaft with at least one key-zone arranged in the axial direction on the outside of the shaft, with at least one key mounted in the key-zone, and at an end of the shaft a spring positioned against a collar of the shaft;—pushing the tool against the motor system, whereby an adapter is mounted in the tool, the adapter comprising a seat, the seat comprising: at least one keyway so that the drive shaft with mounted key can be pushed in the adapter; within each keyway a recess for each key-zone, which recess allows the drive shaft to be rotated relative to the adapter when the drive shaft is inserted so deep into the adapter that the spring is under pressure, and whereby the recess has a blocking element behind which the mounted key blocks, so that the spring is pressed by the adapter in the tool;—rotating the tool until the key ends up in the keyway;—sliding the tool over the drive shaft. 
     It is an advantage of embodiments of the present invention that the dismounting of the tool from a motor system can be accomplished without additional mechanical aids. 
     The method may furthermore comprise securing the adapter in the tool by means of mechanical pressing and/or bonding or by constructing the adapter in the tool, for example by casting. 
     It is an advantage of embodiments of the present invention that, due to a rigid connection between the adapter and the tool with cylindrical cavity, slip between the two is prevented. 
     Particular and preferred aspects of the invention are set out in the accompanying independent and dependent claims. Features from the dependent claims may be combined with features of the independent claims and with features of other dependent claims as appropriate and not merely as explicitly set out in the claims. The above and other aspects of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  shows a 3D exploded view of a drive shaft, an adapter mounted in a tool, and a felt disc, according to an embodiment of the present invention. 
         FIG. 2  shows a front view of an adapter according to an embodiment of the present invention. 
         FIG. 3  shows a 3D view of an adapter, according to an embodiment of the present invention. 
         FIG. 4  shows a 3D view of the adapter of  FIG. 3 , the recess is easily visible in this figure, in accordance with an embodiment of the present invention. 
         FIG. 5  shows a 3D view of a compression spring, which is a part of the drive shaft, according to an embodiment of the present invention. 
         FIG. 6  shows a cross-sectional view of two contiguous adapters mounted in a tool, and fitted on a single drive shaft, according to an embodiment of the present invention. 
         FIG. 7  illustrates a method for mounting a tool having a substantially cylindrical cavity by means of a mounting system on a shaft of a motor system, according to an embodiment of the present invention. 
         FIG. 8  illustrates a method for dismounting a tool having a substantially cylindrical cavity, mounted by means of a mounting system on a shaft of a motor system, according to an embodiment of the present invention. 
         FIG. 9  illustrates another example of a mounting system according to an embodiment of the present invention. 
     
    
    
     The drawings are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. Any reference signs in the claims shall not be construed as limiting the scope. In the different drawings, the same reference signs refer to the same or analogous elements. 
     DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
     The present invention will be described with respect to particular embodiments and with reference to certain drawings, but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. The dimensions and the relative dimensions do not necessarily correspond to actual reductions to practice of the invention. 
     Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein. 
     Moreover, the terms top, bottom, above, front and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other orientations than described or illustrated herein. 
     It is to be noticed that the term “comprising”, used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression “a device comprising means A and B” should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B. 
     Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments. 
     Similarly it should be appreciated that in the description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention. 
     Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination. 
     In the description provided here numerous specific details are put forward. However, it is understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description. 
     Where in embodiments of the present invention reference is made to “the width” of the drive shaft or “the width” of the adapter, reference is made to the distance between the ends of the drive shaft or adapter, and this in accordance with the axial direction of the drive shaft or adapter. Where in embodiments of the present invention, reference is made to “adapter being shifted over a shaft”, this is of course equivalent to “a shaft being inserted or slid in an adapter”. 
     In a first aspect, the present invention relates to a mounting system  100 , an example of which is shown in  FIG. 1 , for the mounting of a tool  161 , typically having a cylindrical cavity in which an adapter  150  is provided for driving. This tool  161  can be a sanding wheel or a grinding wheel. Other abrasive wheels, such as polishing wheels, fleece wheels and flap wheels are also possible. Drive Rubbers, inflatable wheels, ventilated wheels, and other non-mentioned abrasive and wheels with polishing materials can also belong to the possibilities. The drive technology can be used for various tools in various industries such as the metal, non-ferrous, plastic, glass and stone industry. 
     The mounting system  100  comprises a drive shaft  110  that consists of a shaft  111  with at least one key-zone  112 , at least one key  113 , with at an end of the shaft  110  a collar  114  against which a spring  115  (possibly a compact compression spring) can be placed. The shaft  111  has at least one key-zone  112 , but the number of key-zones can be much larger, for example, the key-zones may be arranged in diametrically opposed pairs, whereby multiple pairs, if present, are aligned with each other. For example, the shaft may comprise at least two, or at least four, or at least six, etc. key-zones  112 . The keys  113  may be mounted in the key-zones  112 . Alternatively, the keys  113  may also be mountable in the key-zones  112 , but for example not fixed thereto. 
     The mounting system  100  also comprises an adapter  150  which comprises a seat  155 . The seat  155  forms a cavity for receiving the drive shaft  110 . The cavity formed by the seat has at least one inner diameter corresponding to the outer diameter of the shaft  111 . A small (e.g. minimal) clearance between the adapter and the drive shaft can allow that the shaft  111  can slide smoothly in the adapter  150  and can be rotated relative thereto (during mounting). The adapter  150  is the carrier and actuator of the tool  161 . 
     For each position of a key-zone  112  on the shaft  111 , a keyway  151  is present in a corresponding position on the inside of the adapter  150 . The keyway  151  is positioned so that the drive shaft  110  with mounted key  113  can be slid into the adapter  150 . Furthermore, the keyway  151  is provided with a recess  152  for each key-zone  112 . This recess  152  allows the drive shaft  110  to be rotated (relative to the adapter  150 ) when the drive shaft  111  is fully inserted into the adapter  150  (i.e. when the spring is compressed). After the shaft  111  has been rotated (relative to the adapter  150 ), the spring  115  ensures that the drive shaft  110  is firmly (albeit releasably) mounted in the adapter. More specifically, the key  113  is pressed against a first portion  153  of the recess  152  by the pressure induced by the spring  115 . In one specific example, the key  113  is pressed against a shoulder  153  of the recess  152  as soon as the shaft  111  is rotated (relative to the adapter  150 ) during the mounting. In this way, the recessed area  152  in the keyway  151  makes an excellent connection with the key  113  mounted on the drive shaft  110 . Thus mounted, the drive shaft  110  can transfer a moment of torsion to the adapter  150 . The key  113  pushes against a second portion  205  of the recess  152 . The second portion of the recess  152  where the key  113  pushes against in order to bring about a moment of torsion, is called the “key driving zone”  205 . Due to the spring tension, the adapter  150  gets a radial and axial fastening that results in less vibrations during rotation of the tool  161  with cylindrical cavity. When sanding or grinding stainless steel (or the like), this results in a better finish. The cloud-like appearance caused by excessive wheel clearance as seen in the prior art, is thus substantially reduced or even eliminated. 
       FIG. 1  shows a 3D view of the various parts of a mounting system  100  according to an embodiment of the present invention. In  FIG. 1 , the mounting system  100  is shown in a partly mounted state. The mounting system  100  consists of a drive shaft  110  and an adapter  150 . The drive shaft  110  comprises a shaft  111 . On the shaft  111  at least one key-zone  112 , and at an end of the shaft  111  a collar  114  is provided. In a key-zone  112  on the drive shaft  110  at least one key  113  is (fixedly or removably) mounted. (typically one key  113  is provided in each key zone  112 ). A spring  115  is slid on the shaft  111  until it reaches the collar  114 .  FIG. 1  also shows the adapter  150 , which in this example is inserted in a tool  161 . The adapter  150  has a keyway  151  (e.g. a groove) for receiving a key  113 , and the keyway  151  has a recess  152  (better shown in  FIG. 4 ). The adapter  150  may be made of plastic, although the invention is not limited thereto. 
     In an embodiment of the present invention, the drive shaft  110  comprises two key-zones (also called: a double key groove  112 ) and keys  113 . In preferred embodiments, the system is provided with a compact compression spring or compression spring as shown in  FIG. 5 , but other types of springs, e.g. wave springs or piston springs may also be used. In an embodiment of the present invention, the shaft  111  is provided with a drive zone  116  for connection of the drive shaft  110  with a motor system. This drive zone  116  can have various shapes. In the example shown, the drive zone is an M14 female screw thread. Other types of drive zones, such as ⅝″ screw thread or a pin take-up, or any other suitable drive zone known by the skilled person are also possible. It is an advantage that the driving zone  116  which provides the connection between a motor system and the tool  161  is located on the shaft  111  (and not on the adaptor  150 ), so that by providing a different type of shaft  111 , the same adaptor and tool assembly (as shown e.g. in  FIG. 1 ) can be used also for devices (e.g. sanding/grinding machines) with a different type of mounting connection (e.g. another size of screw thread, or not screw thread at all). 
     In an embodiment of the present invention, two parallel flat faces are present on the shaft which lie at a predefined distance from each other. This makes it possible to exert a moment of rotation on the shaft  111  by making use of a wrench. 
     In embodiments of the present invention, the drive shaft  110  is mounted on portable or hand-held polishing or sanding or grinding machines. These machines contain a spindle blocking mechanism or spindle lock. In most cases, these devices have a drive element with an M14 or ⅝″ screw thread. The drive shaft  110  is mounted thereto. Other drive elements like pin insertion and the like are also among the possibilities. 
     The drive shaft  110  and adapter  150  are designed as an alternative to the currently known sanding/grinding wheels in this target group. Other sizes of adapter and drive shaft are possible, both for rotating and non-rotating tools. It should be noted that the mounting system of the present invention is especially suitable for rotating tools, where it allows a quick mounting or change-over of the tool, as well as an assembly with little or no play. 
     The attachment of the adapter  150  in the tool  161  (comprising abrasive material), for example having a cylindrical cavity, can be achieved in different ways. In an embodiment of the present invention, this can be accomplished by mechanical pressing. In another embodiment, this can be accomplished by gluing by means of glue or resin. The combination of both pressing and gluing is also possible. 
     The outer periphery of the cross section of the adapter  150  preferably has a polygon-like shape. This polygon-like shape has at least three corners, but more corners, e.g. four, five, six, eight or more than eight corners are also possible. In the example, six corners are shown. In an example, the sides of the polygon-like shape are concave, and the corners are flattened, but the invention is not limited to such shapes. In a specific embodiment the entire width (i.e. in its axial direction) of the adapter  150  comprises concave surfaces  203  and pressing faces  202 . In the rest of the description, this particular outer circumference is referred to as “special star shape.” The special star shape makes it possible to use various fastening techniques. For example, the adapter  150  can be mechanically pressed into the (e.g. plastic) inner core of the tool  161 . The inner diameter of the inner core—of the diameter of the cylindrical cavity thereby formed—of the tool  161 , and the outer diameter of the adapter must be matched to each other. Suitable, e.g. the most suitable press tolerance can be determined e.g. in cooperation with the manufacturer of the tool  161 , in accordance with the highest standard and/or best practice of the known techniques used today. Optionally additional bonding can also be applied. When bonding with resin or other adhesive substances the attachment surface of the adapter will be increased due to the special star shape of the adapter  150 . Due to this specific shape, the maximum force the adapter can take is (much) increased, and slippage of the adapter relative to the tool with the cylindrical cavity  161  is (strongly) reduced or even eliminated. Such bonding techniques are known today, and should preferably be applied in accordance with the best industry practices. 
       FIG. 2  shows a possible embodiment of the outside of the adapter. The concave surfaces  203  provide a better bonding of the resin by increasing the surface area and ensure that the adapter  150  does not slip relative to the tool  161  with cylindrical cavity. The pressure faces  202  provide a suitable (e.g. perfect) means for pressing the adapter into the core of a tool  161  with cylindrical cavity. The keyway  151  facilitates a swift mounting of the adapter  150  over the drive shaft  110 . In the embodiment of the present invention illustrated in  FIG. 2 , the angle of rotation that needs to be made in order to secure the tool with cylindrical cavity  161  on the drive shaft  110 , is 45°. 
     The adapter  150  can be made having an outer diameter corresponding to the inner diameter of the tool to be mounted. 
     Alternatively, the adapter according to the present invention can also be constructed directly, for example moulded, in the tool. This can be achieved using known production techniques. One example of this is the direct moulding of the adapter  150  in the opening of the tool  161 , whereby a flexible element having the shape of the drive shaft  110  to be mounted therein later, is (temporarily) positioned in the opening of the tool  161  during moulding for safeguarding the opening where the actual drive shaft is to be positioned after the step of moulding and removal of the flexible element. 
     The width of the adapter (in its axial direction) may vary. In one specific example, the width of the adapter (i.e. the size that corresponds to the length of the piece along the axial direction) is approximately 50 mm. Because the adapter can be used in a modular way, the adapter  150  can be extended in the width direction of the tool. This makes it possible to use a single type of adapter  150  to mount tools  161  having different widths. For hand-held or portable machines a manageable width of 200 mm is possible. This width is, however, not limited by the present invention. When multiple adapters  150  are used for mounting a tool, the width of the drive shaft  110  should be adjusted accordingly. For example, in the case of multiple adapters each having a width of 50 mm, the width to be bridged by the drive shaft (that is, the distance from one end of the drive shaft  110  to the compressed spring  115 ) is 50, 100, 150 or 200 mm in the case of 1, 2, 3 or 4 adapters respectively. Due to the modular nature of the adapter and by providing drive shafts of appropriate length (corresponding to once, twice, 3 times, 4 times, etc. the width of the adapter) tools of different widths can be fitted. Alternatively, individual adapters can be made having the same width as the width of the tool, which may but need not be multiples of 50 mm. In other words, the adapters may alternatively also be provided with such dimensions as required for completely taking up the central opening of conventional tools. 
     The outer diameter of the tool may vary, and may in a specific example be a value in the range between 100 mm and 130 mm. 
     In embodiments of the present invention, there are two keys  113  on the drive shaft for each adapter. These keys are located diametrically opposite each other (relative to the virtual axis of the drive shaft) and serve to drive the adapter. In the above example (with multiple adapters), this corresponds to drive shafts  110  comprising two, four, six or eight keys  113 , depending on the width of the drive shaft. 
     In embodiments of the present invention, the tool with cylindrical cavity may be a sanding wheel or a grinding wheel. When a sanding/grinding wheel width of 150 mm is to be achieved, one can make a combination of a sanding/grinding wheel of 100 mm and a sanding/grinding wheel of 50 mm on a drive shaft of 150 mm. In that way the wheels can be assembled (in the width direction) to a desired accumulated width. 
     In some embodiments of the present invention, there are two keys  113  (hence also two key slots  112 ) present on the drive shaft for each adapter  150 , at diametrically opposed sides of the drive shaft. When assembled, these keys  113  provide a good connection between the drive shaft  111  and the adapter  150 , so that any vibration can be strongly reduced or even completely eliminated.  FIG. 1  shows an exploded view of a partly assembled drive shaft  110  in an arrangement for a  100  mm sanding/grinding wheel width. This arrangement comprises a solid shaft  111  having a drive zone  116  and a flattened zone  117  to permit the drive shaft to be connected to the spindle of a motor system using e.g. a 19 mm wrench. The motor system can for example be a polishing machine. The spring  115  (optionally a compact compression spring), is in the example of  FIG. 1  adhered to the collar  114  (spring-stop) of the shaft  111  with an adhesive for metal. In the example of  FIG. 1 , the four keys  113  are glued in the milled key grooves  112  using glue for metal, and provide guidance for mounting the sanding/grinding wheel  161  including adapters  150 .  FIG. 6  shows additionally a worm thread, that acts as a quick-change connection  602  and can be used for the mounting of a felt  162 , and a threaded borehole  603  (in the present example, an M5 threaded bore), which can be used for the mounting of existing sanding or grinding wheels on the drive shaft. In the latter case, the sanding or grinding wheel is attached to the adapter  150  by means of a washer and a bolt M5. 
     In the first case a felt  162  is mounted in order to protect the material (e.g. stainless steel) against sanding or grinding from the abrasive side of the sanding or grinding wheel  161 . Especially when sanding/grinding sides arranged perpendicular to each other (i.e. at) 90°, this can be a help. 
     In this way, the mounting system  100  is also compatible with already existing components. 
     In an embodiment of the present invention, the key  113  is rounded at both ends as shown in  FIG. 1 . This key-radius provides the axial locking of the adapter (after mounting). In other embodiments of the present embodiment, other widths of the drive shafts (e.g. 50 mm, 100 mm, 150 mm) are possible, but the invention is not limited to widths being multiples of 50 mm, and other widths, e.g. about 60 mm, about 70 mm, about 80 mm, about 90 mm, about 110 mm, etc. are also possible. In the example of  FIG. 1 , the sanding or grinding wheel  161  has a width of 100 mm and contains two adapters  150  (only one is visible), each having a width of 50 mm, which adapters are glued in the sanding or grinding wheel. In another embodiment of the present invention, it is possible that these adapters  150  are mechanically pressed into the hard core  154  of the sanding or grinding wheel. The shoulder  153  of the recess  152  of the keyway  151 , which is a radius seating in the embodiment shown in  FIG. 4 , has a shape complementary to the shape of the corresponding end of the key  113 , so as to form a matching connection with the key-radius. As stated above, the adapters  150  may also be constructed directly in the tool  161 , for example, by moulding. It may form a monolithic part with at least the core of the tool, or it may be moulded after the formation of the tool. In the latter case it could be made of a different material than the core of the tool. 
     Alternatively, adapters with a larger width (e.g. larger than 50 mm) may also be provided, so that a modular system containing multiple contiguous adapters, is not required. 
     In an embodiment of the present invention a marking  201  present on the adapter  150  indicates which side has to be slid over the drive shaft  110  first, and indicates as well the direction in which the adapter  150  has to be rotated with respect to the drive shaft  110  in order to rotate the keys  113  towards the recess  152  of the keyway  151 . One possible embodiment of suitable markings is illustrated in  FIG. 2 .  FIG. 2  shows a side view of an adapter  150  (perpendicular to the axial direction). Lock and unlock marking  201  are arranged on the adapter  150  to indicate the direction in which the adapter has to be rotated relative to the drive shaft to fasten or connect (lock) the adapter to, respectively, to loosen or disconnect (unlock) the adapter from the drive shaft. The side of the adapter  150  with the markings may be the side of the adapter that has to be slid over the drive shaft first (or stated otherwise, may be the side of the adapter where the drive shaft is to be inserted). Alternatively, as in the embodiment shown in  FIG. 2 , the markings  201  may be present on the side that is to be slid over the drive shaft  110  last, that is, the non-machine side. 
     In an embodiment of the present invention, the adapter-side on which the markings  201  are present has a V-connection  301 , the other side has an M-connection  401  (see  FIG. 6 ). When multiple adapters are arranged contiguously to each other, the V-connection  301  from one adapter fits perfectly to the M-connection  401  of the other adapter. In  FIG. 3 , the V-connection  301  is clearly visible. Furthermore, the adapter seat  155  is also visible in  FIG. 3 . The seat (in particular the inner diameter thereof) is made as accurately as possible, for positioning the tool with cylindrical cavity  161  as accurately as possible on the drive shaft  110 . In the example of  FIG. 3 , the recess  152  in the key-zone  151  extends to one end of the adapter  150 . This allows clearance of the key  113 , since the width of the recess  152  is wider than the width of the key  113 , so that the adapter  150  can be mounted on the drive shaft  110 . Due to this clearance zone  601 , it is possible to rotate the adapter over an angle of 45° relative to the drive shaft  110  so that the key  113  can be rotated until it reaches the recess  152 . 
       FIG. 4  shows the same adapter  150  as shown in  FIG. 3 , but seen from the opposite side. This side is the machine side of the adapter, i.e. the side facing the machine when mounted on the drive shaft. The M-connection  401  is visible on this side. The shoulder  153  against which the key  113  will rest after assembly is a radius seat in this example, as can also be seen in  FIG. 4 . In this way, a suitable (e.g. perfect) one-to-one connection is realized between the key radius (at an end of the key  113 ) and the radius seat  153 , due to the substantially constant pressure of the compact compression spring  115 . The side of the recess  152  parallel to the axial direction of the adapter  150  shown in  FIG. 4 , is the drive zone  205  for the adapter, which in turn will drive the tool  161  with cylindrical cavity  161 . When this model of adapter is mounted on drive shafts having a continuous key (in contrast to multiple keys shown in  FIG. 1 ), the torque transmission can be accomplished through the drive zones  204  of the keyway  151  (portion where no recess  152  is made). Also in this case the adapter seat  155  carries the adapter  150  on the drive shaft  110 . 
     In an embodiment of the present invention, the spring  115  is a compact compression spring.  FIG. 5  shows a schematic representation of an example of a compact compression spring, but other compression springs are also possible. The outer diameter  502  of the compression spring fits (e.g. perfectly) on the adapter  150  and provides the necessary axial pressure. The inner diameter  501  slides with a small, e.g. minimum clearance over the outer diameter of the drive shaft  110  until it reaches and rests against the collar  114  which acts as a stop collar for the spring, and a flat zone  503  of the spring  115  may be glued to the collar  114 . The number of corrugated strips  504  along with the design (e.g. material, strip thickness, etc.) of the spring  115  provide the necessary compactness and pressure. 
       FIG. 6  shows a sectional view of a mounted tool  161  having a hard core  154  with a cylindrical cavity and with two pressed-in adapters  150 , mounted on a complete drive shaft  110  (i.e. a drive shaft including keys  113 ). A quick-change connection  602 , in this case a worm thread, is visible in this drawing. This quick-change connector  602  allows to fit a felt disk  162  (see  FIG. 1 ). Extending inside the quick-change connector opening  602  is a tap M5  603  visible, for optional mounting of wheels with a continuous keyway. These can be fitted with a washer  164  and bolt  163 . The two clearance zones  601  for the keys  113  are also visible in  FIG. 6 . In the detailed view ( FIG. 6 -top), the end of the M- and V-connection  401 ,  301  can be seen. This can be used for avoiding infiltration of glue during the pouring of glue after insertion of the adapter  150  in the sanding/grinding wheel  161 . 
       FIG. 9  shows, by way of illustration, another example of a mounting system according to an embodiment of the present invention. 
     In a second aspect, the present invention relates to a method for mounting (or assembling or attaching or connecting or fitting)  700  or dismounting (or disassembling or detaching or disconnecting or unfitting)  800  a tool  161 , for example a tool with a cylindrical cavity, by means of a mounting system  100  to/from a shaft of a motor system. The motor system may for example be a polishing machine with a spindle blocking mechanism or a spindle lock. 
     Referring to  FIG. 7 . When mounting, the drive shaft  110  is mounted, in a first step  710 , to the motor system (e.g. the polishing machine). In an exemplary embodiment of the present invention, the connection between the drive shaft  110  and the shaft (or spindle) of the motor system is based on a female M14 screw thread on the drive shaft side and an M14 male screw thread on the motor side. In an exemplary embodiment of the present invention, the drive shaft is secured to the motor system by making use of a wrench of size 19 mm. Other connection systems and connection tools may also be used. Although this step (of securing) is indicated as the first step during assembly, in principle, this step can also be performed afterwards, and the drive shaft may be coupled to the tool before connection to the motor system. 
     In a next step  720 , the tool  161 , for example having a cylindrical cavity before assembly, is slid over the drive shaft  110 . For this purpose an adapter  150  needs to be present in the tool  161  with the cylindrical cavity. Such an assembly can be performed in several ways, some of which were already described above with reference to the first aspect. The keyways  151  in the adapter  150  must be slid over the keys  113  of the drive shaft  110 . In an exemplary embodiment of the present invention, a marking  201  may be present on the adapter  150  to indicate which side of the adapter  150  must be slid first over the drive shaft  110 . This marking  201  also indicates the direction in which the adapter  150  has to be rotated with respect to the drive shaft  110  in order to rotate the key  113  towards the recess  152  up to the key driving zone  205 . In an embodiment of the present invention, this marking  201  to a lock/unlock marking. In this case one has to take into account that the adapter with the inscription “Lock/Unlock” is not slid on the drive shaft  110  first. When a spindle lock is provided on the motor system, this can be pressed to block the drive shaft (step  730 ). In a next step  740 , one pushes the tool  161  with cylindrical cavity with a light pressure against the spring  115 , which may for example be a compact compression spring. The spring  115  is then fully pressed by the adapter  150  into the tool  161  with cylindrical cavity. Without reducing the pressure on the spring  115 , one rotates the tool  161  with cylindrical cavity relative to the drive shaft until the key  113  reaches the recess  152  and cannot move further. In an embodiment of the present embodiment, this means rotation over an angle of 45° in the direction indicated by “Lock”. In a next step  760 , the tool with cylindrical cavity  161 , and in the case of a spindle lock also the spindle lock, is/are released. At this (mounted or assembled) stage, the spring  115  pushes the key(s)  113  against the shoulder(s)  153  of the recess(es)  152  in the adapter  150 . The shoulder  153  may be a radius seat and may form a 1-to-1 connection between the key  113  (of the drive shaft) and the radius seat  153  (of the adapter  150 ). In case the tool with cylindrical cavity  161  is a grinding wheel or a sanding wheel, the grinding or sanding operation can now start. The keys  113  push against the drive zone  204  or  205  of the adapter  150  to rotate the grinding or sanding wheel in the right direction, and the compression spring  115  keeps the adapter  150  under constant pressure during the rotation. There is no vibration of the wheel noticeable because of this constant pressure of the spring  115 . 
     Referring to  FIG. 8 . During dismounting (or disassembly), in a first step  810 , the spindle of the motor system is blocked, for example by means of a spindle lock. Subsequently, step  820 , the tool  161  with cylindrical cavity is pushed against the spring  115 . In a next step  830 , the adapter  150  is rotated relative to the drive shaft  110  until the key(s)  113  are positioned in the keyway(s)  151  (e.g. aligned with the entrance of the keyway). In an embodiment of the invention, this means that the tool with the cylindrical cavity needs to be rotated over 45° in the direction indicated by “Unlock”. In the case a radius seat  153  is used, only a limited force needs to be exerted by the radius of the keys  113  (present on the drive shaft  110 ) and the radius seat  153  (present in the adapter  150 ) against the spring  115  (e.g. compression spring). In this case, one can feel when the tool  161  with the cylindrical cavity clicks out of the radius seat  153 . In case of a spindle lock, this lock can now be released, and the tool with the cylindrical cavity can be removed from the drive shaft (step  840 ), by sliding. 
     In a third aspect, the present invention relates to an adapter  150  for use with a drive shaft  111  for driving a tool  161 , e.g. a sanding or grinding tool. The adapter comprises the features as described for the adapter from the mounting system of the first aspect. Optional features as described in the first aspect are also optionally present in the adapter of the third aspect. Such an adapter can be formed or shaped in such a way that it can be used in a modular way to obtain an adapter with a larger width (e.g. larger than 50 mm) for driving a tool with a larger width (e.g. larger than 50 mm). The adapter may, for example have a top side and a bottom which are complementary in shape, so that the top side of one adapter matches the bottom side of another adapter. 
     In a fourth aspect, the present invention relates to a drive shaft  111  for use with an adapter  150  for driving a tool  161 , e.g. a sanding or grinding tool. The drive shaft  111  comprises the features as described for the drive shaft  111  of the mounting system  100  of the first aspect. Optional features as described in the first aspect are also optionally present in the adapter of the third aspect. 
     In a further aspect, the present invention also relates to a method for producing a tool  161 , in particular a grinding tool or a sanding tool, the tool  161  comprising an adapter  150  as described above. In the embodiment where the core  154  of the tool is formed integral with the adapter  150 , of course to polygonal-like shape and concave surfaces and flattened ribs, and gluing etc. can be omitted, but the internal structures (keyway  151 , recess  152 , radius seat  153 , etc) are still required. The production method may, for example, comprise the direct moulding of an adapter  150  in such a tool (e.g. sanding or grinding tool), whereby an insert, for example having a flexible shape, is provided in the mould for keeping the location where the actual drive shaft is to be positioned later, open. Alternatively, the adapter  150  can also be made separately (i.e. as standalone component), for example by moulding or casting in a mould, and be inserted in a cavity of the tool (using pressure), and may then optionally or preferably, be glued or bonded thereto. 
     The various aspects can be readily combined with one another, and such combinations, for example a kit of parts comprising at least two or at least three different components selected from the group of a drive shaft  110 , a key  113 , an adaptor  150  and a grinding or sanding wheel  161 , especially when having the same or corresponding dimensions, therefore also represent embodiments of the present invention.