Patent Application
20160229028
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.
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.
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.
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.
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
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.
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
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.
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.
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
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
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
In an embodiment of the present invention, the spring 115 is a compact compression spring.
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
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
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.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2013/0607 | Sep 2013 | BE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2014/069640 | 9/15/2014 | WO | 00 |
