The invention to which this application relates is to an improvement in abrasion apparatus and particularly, although not necessarily exclusively, abrasion apparatus in the form for removing material from a workpiece such as by sanding.

Abrasion power tools typically include a drive motor and the motor is connected to rotate or otherwise move a spindle or a plate. Directly or indirectly fitted to the spindle or plate is an abrasion component typically provided as a drum comprising a body with engagement means to allow the same to be engaged to the spindle and on at least one surface of the drum there is provided a backing layer and onto which is provided a bonding material and particles of a relatively hard wearing material of selected dimensions so as to form the external abrasion surface of the component. The abrasion surface is provided so as to be selectively contacted onto a surface of a workpiece which is to be abraded so as to allow the removal of material from the workpiece and hence create a smoother surface of the same and/or reduce the dimensions of the workpiece. The extent of change and the amount of material removed from the said surface via the movement of the abrasion surface, can vary but generally, the aim is to provide a surface which is smoother than prior to the work being performed thereon and/or to allow the dimensions of the workpiece to be altered and reduced to a specified amount.

The power tool sander to which this application is particularly related includes a spindle onto which there can be mounted at a time of use, one of a selected number of abrasion components. Typically, the selection of an abrasion component of a particular form, along with the type of abrasion material provided thereon allows the user to match the component to best suited to the particular work which is to be performed at that time. The apparatus is designed to be mounted on a worktop with a housing base with the spindle exposed therefrom to receive the selected abrasion component thereon and rotate the same. The housing can also include storage means to allow the range of selectable abrasion components to be stored thereon and be selectively moved and fitted onto the spindle, with the selection made with respect to the size, shape and form of the workpiece so as to allow the appropriate surface of the workpiece to be moved into contact with the abrasion surface of the component when rotating.

The housing receives a power supply thereto and includes the motor therein which is provided to rotate the spindle once power is supplied to the said motor. Conventionally, the motor is provided to operate at a fixed speed regardless of the particular abrasion component which is mounted on the spindle at that time. It is found in practice, that this means that while for certain of the selected drums and/ or abrasion materials and/or types of workpiece materials, the speed of spindle rotation is such as to meet the requirements for an effective work operation to be performed, for other abrasion components the speed of rotation is not such as to allow optimum performance to be achieved which may mean that an inferior work performance is obtained or that certain types of component which could be usefully provided, are not included in the range of selectable abrasion components.

For example, if the workpiece is made of wood, it is known different types of wood react differently to heat generated by friction during the work operation and so the conventional use of the same speed of movement the abrasion material may be optimum for certain types of wood, adequate for other types of wood or detrimental for other types of wood. Also, it is found that the use of the same speed of movement for certain workpiece material can lead to the relatively fast degradation of the abrasion surface leading to additional expense to the user and rapid clogging of the apparatus from the abrasion surface and/ or workpiece debris.

Thus the conventional apparatus can be regarded as a compromise in terms of performance and can lead to the apparatus not being used by, for example, persons who wish to obtain a relatively high quality finish. An aim of the present invention is to adapt and improve the power tool sander in a manner which allows the selection and use of a range of abrasion components and for the power tool sander to be adaptable in terms of performance with respect to the particular abrasion component fitted at that time of use. A further aim is to allow the apparatus to be adaptable by the user in order to optimise the performance of the apparatus for each of the abrasion components when selected to be fitted to the spindle for rotation. A further aim of the invention is to allow the apparatus to be adaptable with respect to operation of the same with respect to the same abrasion component mounted thereon, so as to allow the abrasion component to be used in different stages with respect to the workpiece.

In a first aspect of the invention, there is provided aan abrasion power tool apparatus, said apparatus including a housing, a motor which, when provided with a power supply, is operable to rotate at least one spindle located externally of the said housing, one or more abrasion components including an abrasion surface, said one or more abrasion components selectively engageable with the spindle such that, when engaged, the abrasion component is rotated by the spindle to perform a work operation on the surface of a workpiece placed against the same and wherein, the apparatus includes adjustment means to allow the adjustment of the speed of rotation of the spindle to a selected speed within a range of speeds, with the selection being made with respect to the abrasion component fitted to the spindle and/ or the work operation to be performed on the workpiece at the instant of time of use.

In one embodiment, the operation of the adjustment means, is manually performed by a user of the apparatus. In one embodiment, when adjustment of the speed is performed manually, a user adjustable mechanism is provided, typically on the housing means which is accessible by the user to be adjustable. In one embodiment, the adjustment means used to allow user manual adjustment of the speed of rotation of the spindle via control of the operation of the motor, is a dial switch which is located on a face of the housing in conjunction with a numerical graduation to allow the user to select the particular position of the dial to suit a desired adjustment means setting.

In one embodiment the apparatus may include guide means which provide the user with an indication of the appropriate setting of the adjustment means for each of a plurality of abrasion components when fitted to the spindle and/ or for specific uses or stages of use of an abrasion component

In addition, or alternatively, the setting of the adjustment means is performed automatically upon the engagement of the particular abrasion component with the apparatus.

In one embodiment, when the speed of adjustment of the spindle is performed automatically, the particular setting of the adjustment means, is achieved as a result of a coded mechanical engagement of a particular abrasion component with the spindle at that time with the coded engagement translated into a particular setting for the adjustment means.

In whichever embodiment, the particular setting of the adjustment means controls the operation of the motor and, in turn, the speed of rotation of the spindle to be a speed which is best suited to impart movement and operation of the particular abrasion component which is attached to the spindle at that time so as to perform the best working operation on a surface of the workpiece.

Typically, the housing of the apparatus includes a series of storage areas in which the abrasion components which are provided to be selectively fitted to the spindle, are stored.

In one embodiment, the housing includes a platform which is located adjacent to the spindle and typically the angular position of the platform with respect to the body, can be selectively adjusted to suit the particular component which is fitted to the spindle and/ or the size and shape of the component on which the work is to be performed.

Typically, the motor which is used is a brushless motor or brushed motor.

Typically, in addition to the dial switch, there are provided on and off switches.

Thus, in accordance with the invention, there is provided apparatus which can be adapted to operate in a selected format which allows the performance of the apparatus to be optimised with regard to the specific abrasion component fitted to the apparatus at that time and/or with respect to the type of work being performed on a workpiece by using the apparatus.

Typically the abrasion components which are provided in the range of selectable components include one or more drum components which are typically provided to be driven to rotate about a longitudinal centre axis of a channel in which the spindle is received and engaged. In one embodiment the abrasion components which are provided in the range of selectable components include one or more belt components which have two spaced apart members, one of which is mounted on said spindle to allow the same to be driven and hence move the belt abrasion component.

In a further aspect of the invention, there is provided a method of using an abrasion power tool apparatus said method including the steps of mounting the apparatus on a support surface, selecting to locate and engage an abrasion component including an abrasion surface on at least one spindle located on said housing, providing a power supply to a motor to operate the same and rotate the said spindle and abrasion component, bringing a workpiece into contact with the moving abrasion surface to perform a work operation on the surface of the workpiece and wherein operating adjustment means to select the speed of rotation of the said spindle prior to and/ or during the performance of the said work operation. In one embodiment once the setting of the adjustment means has been selected with respect to the selected abrasion component then the setting is maintained during the work operation. In an alternative embodiment the setting of the adjustment means may be altered deliberately as the performance of the work operation occurs.

In one embodiment the setting of the said adjustment means is made by a user with reference to predetermined setting values for the specific abrasion components which are made available to the user. The apparatus may include guide means 31 which provide the user with an indication of the appropriate setting of the adjustment means for each of a plurality of abrasion components when fitted to the spindle and/ or for specific uses or stages of use of an abrasion component

Alternatively or in addition, each of the abrasion components has a mechanical or wireless coding provided as part thereof such when the said abrasion component is selected and removed from the storage area for that component and/or engaged with the spindle then the adjustment means are automatically set to a predetermined value for that abrasion component and/or a setting value is displayed to the user. The wireless detection may be via RFID, Bluetooth or other wireless communication system.

It will be appreciated that the setting value which is made for the adjustment means will rotate the spindle at a specific speed and that the speed which is set may still vary during use of the abrasion component to perform the work operation as a result of any, or any combination of, friction, the type of work being performed, the material of the workpiece and/or force with which the user may apply the workpiece to the component.

Specific embodiments of the invention are now described with reference to the accompanying Figures; wherein Figures la-c illustrate one embodiment of the apparatus in accordance with the invention in one configuration for use;

Figure 2 illustrates the apparatus of Figure 1 in a further configuration of use;

Figures 3a and b illustrate embodiments of adjustment means of the apparatus of Figures la-2 in one embodiment; and

Figure 4 illustrates a range of abrasion components in accordance with one embodiment of the invention.

Referring firstly to Figures la-c there is illustrated apparatus 2 in accordance with one embodiment of the invention. The apparatus includes a housing 4 to which there is provided a power supply 6 which passes to a drive means in the form of a motor provided within the housing. The motor is connected to rotate a spindle 8. The housing is provided to be mounted on a support surface 10 such as that of a work bench. The housing also includes a support platform 12 which is angularly adjustable between horizontal to vertical via operation of the adjustment mechanisms 14 and is used to provide support for the workpiece on which the abrasion, typically sanding, work operation is to be performed.

The spindle is provided to have engaged therewith an abrasion component and most typically an abrasion component which is selected from arrange of abrasion components 16. When engaged the spindle, when driven by the motor rotates and the rotation is transferred to the abrasion component.

A possible range of abrasions components 16 are illustrated in Figure 4 and in Figures la-c the abrasion component in the form of a belt 16’ is shown in engagement with the spindle 8 and in Figure 2 an abrasion component in the form of a drum 16” is shown in engagement with the spindle 8. Typically each of the abrasion components include a body 18 which includes a channel 20 with means to allow the same to receive therealong and engage with the spindle 8. Onto the body is mounted a replaceable sleeve with the abrasion surface 22. The Figure 4 also illustrates fitting tools and other components which can be provided as and if required. The housing, also in this embodiment includes storages areas 24 for those abrasion components which are not fitted to the spindle but it should be noted that that this is an optional feature. An on/ off switch 26 to allow the selective provision of power to the motor is also provided.

In accordance with the invention adjustment means 28 are provided which in this embodiment are manually adjustable by the user and which will be described in greater detail subsequently.

In use of the apparatus, the user will be aware of the particular type and form of the workpiece on which they wish to perform the work operation. They can then select the particular abrasion component which they believe to be appropriate for the work operation either from their own knowledge or from a reference or instruction manual. They then engage the selected component 16 in position on the spindle 8 and adjust the position of the platform 12 to suit the size, shape and work which is to be performed on the workpiece and to enable the workpiece to access and contact the abrasion surface 22.

The speed of rotation of the spindle and hence speed of movement of the abrasion surface is selected within a range of possible speeds prior to and/or during the movement of the spindle by the user operating the adjustment means 28 which in Figure 3a includes a dial or knob 30 which can be manually rotated about axis 32 or as shown in Figure 3b is in the form of a slidable knob 33. In both embodiments an indicator 34 is provided thereon which can be aligned with speed markings and values 36 provided on the surface 38 of the housing 4 so as to select a specific speed within the range from slowest to fastest. In this embodiment the motor which is used is a digital “brushless” AC induction motor and the adjustment means includes a PCB control circuit 40 connected to the same but located within the housing which allows the manual movement of the dial or knob to be translated into a digital control signal to operate the motor so as to provide rotation of the spindle at the appropriate speed. The PCB can also be set to a particular speed range so as to allow the movement of the dial to be translated to specific speeds for particular abrasion components which may be provided with particular versions of the apparatus. Alternatively, coded means may be provided on the spindle and body of the abrasion component which allow the automatic selection of the speed of rotation of the spindle depending on the particular coded arrangement between the body and spindle ta that time and a control signal representative of the coded configuration is sent o the control means for the motor. Further means of actuation and adjustment of the speed of the spindle can include any or any combination of digital and analogue switches, dials, touchscreens, sliders, push buttons, capacitive switches or the like and therefore any suitable user interface could be used. Typically some means of visual indication will be provided so that the user is made aware of the speed of operation of the apparatus at an instant of time.

It will be appreciated that the dial can be adjusted during performance of the work operation and/ or prior to the commencement of a work operation with a different selected abrasion component having been fitted to the spindle 8.

The provision of the speed adjustment may be achieved in a number of different ways to that shown here and with different types of motor which and these other means are incorporated within the scope of this application. In whichever embodiment, the adjustment of the speed allows the apparatus to be adapted so as to take into account variations in the abrasion surface of different abrasion components, different forms of workpiece materials and/ or the type of finish which is required to be achieved by the work operation. For example, the variation in speed allows the reaction of different types of wood to the work operation to be taken into account such as with respect to the heat generated by friction and the speed adjustment allows previously problematic types of wood (such as maple) to be sanded at a slower speed to prevent burning of the wood. The ability to adjust the speed of the abrasion surface also allows adjustment of material removal rate. Furthermore, the control of the speed allows a reduced speed to be used in order to achieve a finer sanding detail and generally more control of the work operation.

Also, the use of the different workpiece material can be taken into account by adjusting the speed so that, for example, materials such as GRP which tend to clog- up the abrasion surface and the component in general if the speed is too fast can be worked on at a reduced speed and so extend the lifetime of the abrasive surface.