AU2007211884A1

AU2007211884A1 - Power tool dust and debris extraction

Info

Publication number: AU2007211884A1
Application number: AU2007211884A
Authority: AU
Inventors: Marcus Nicholson
Original assignee: GMCA Pty Ltd
Current assignee: Power Box AG
Priority date: 2006-08-22
Filing date: 2007-08-22
Publication date: 2008-03-13
Also published as: GB2446892B; GB0616564D0; GB2446892A; GB0716215D0

Description

Regulation 3.2 C( AUSTRALIA b PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT O ORIGINAL 0 00 Name of Applicant: GMCA Pty Ltd Actual Inventor: Marcus Nicholson Address for Service: MADDERNS, 1st Floor, 64 Hindmarsh Square, Adelaide, South Australia, Australia Invention title: POWER TOOL DUST AND DEBRIS EXTRACTION The following statement is a full description of this invention, including the best method of performing it known to us.

SI'alAU 132 2 O Power Tool Dust and Debris Extraction

O

The invention to which this application relates is a power tool which in use can create dust and/or debris and the provision of means on the tool to allow the controlled passage of this dust and debris, hereinafter referred to as dust, from the location at which the same is created to a location for collection and/or oo oO dispersal.

Cl 10 The provision of dust extraction means as part of power tool, O such as a sander is well known and many different types of tool include various forms of the same. Conventionally the dust extraction means all include a chamber provided as an integral part of the housing of the tool. The chamber is normally moulded or permanently fixed to the plastic housing which forms the tool body and has a first opening which is at or adjacent to the cutting blade or abrasive surface which is presented to the workpiece to perform the cutting or abrasive surface. The opening is required to be sufficiently close such that dust passes through the opening and into the chamber. The chamber is provided with a second opening through which the dust leaves the chamber to pass onwards on to a collection bag, cartridge or vacuum system where the dust can be collected until it s necessary to discard the same.

In some tools such as, for example, power sanders, there is provided a fan which is in communication with the chamber such that it rotates, typically on the motor shaft, when the tool is powered, and the rotation induces the dust into and through the chamber.

A problem with dust extraction system is that the same can become easily blocked up if the same become full or are blocked in specific places. One known problem is that the chamber of Sthe system can be become clogged up such that dust cannot pass

O

N through the same and hence does not reach the collection bag or cartridge connected to the outlet of the chamber. This means that the provision of the dust extraction system is of no benefit Cl as all of the dust still collects at the interface between the tool and the workpiece and hence can cause malfunction of the tool and/or damage to the workpiece. This problem is exacerbated by 00 0 the fact that the chamber is provided as integral part of the tool and therefore cannot be easily cleaned and in many instances is in fact inaccessible to user using normal cleaning techniques, O especially once the dust becomes compacted in the chamber. A further problem which is experienced if the dust does reach the collection area such as for example, a dust collection cartridge, is that it is not always readily apparent when the collection means is full or is reaching a level of dust within the same which will start to cause inefficient or non operation of the dust extraction system. Because the user can often regard the need to refer to the level of dust within the collection means to be a time consuming chore it is often not done at all or as often as is required.

The aim of the present invention is to provide a dust extraction system for a tool such as a powered sander, in a manner which allows the efficient operation of the dust extraction system to be achieved more readily than is presently the case.

In a first aspect of the invention there is provided a power tool, said power tool having a body and an abrasive surface and/or blade for selective positioning with respect to a workpiece to perform a working operation thereon when the tool is operational, and a dust extraction system, said system including a chamber with an entry opening positioned so as to receive dust and debris created by the working operation and an exit, downstream from the entry and through which the dust and 4 O debris leaves the chamber and wherein said chamber is at least

O

'I partially defined by a unit which can be selectively removed from the body to allow cleaning of the chamber.

(,i In one embodiment the chamber is defined by a wall of the body and said unit when fixed to the body. In an alternative embodiment the unit alone defines the chamber therein.

00oo 00 In one embodiment the unit is fixed to the body by fastening 10 means which in one embodiment can be operated without the

O

Sneed for a tool thereby allowing for the easier release and fixing of the same to the body.

In a preferred embodiment the chamber is in communication with a fan provided in the body said fan provided to induce dust and debris through the entry and through the chamber, the dust and debris leaving the same through the exit.

In a preferred embodiment there is provided in connection with the exit a dust collection means, said dust collection means a bag or cartridge. Typically the bag or cartridge is selectively openable or removable so as to allow dust and debris held therein to be discarded from time to time.

Preferably the dust collection means and/or the tool to which the same is connected include an indication means, the condition of which changes when the amount of dust held within the dust collection means or chamber reaches a predefined amount. Typically the predefined amount which is selected to cause the change in condition is such as to indicate when the collection means is full or is approaching a full condition and will require emptying.

O In one embodiment the visual indication means is electrically or

O

electronically generated via a sensor which is triggered when a certain level of dust is reached, or a reduction in air flow is detected, and the condition of a light is caused to change.

In an alternative embodiment the visual indication is generated l by mechanical means such that when a predefined amount of oo oo dust occurs or a particular airflow occurs a mechanical movement occurs, such as for example the movement of a flag from retracted to a protruding position.

O

It should be appreciated that the change in condition, especially in the mechanical indication means, may be a gradual change rather than an instantaneous change in condition.

In one embodiment the power tool is a sander with an abrasive sanding surface which is powered to move against a workpiece and, more specifically, is a belt sander.

In one embodiment the chamber and/or collection means are provided with a transparent inspection portion therein so as to allow the user to inspect the internal condition of the said chamber and/or collection means. Typically the aperture is sealed externally and has plastic or glass forming the viewing aperture.

In a further aspect of the invention there is provided a power tool, said power tool having a body with an abrasive surface and/or blade for selective positioning with respect to a workpiece to perform a working operation thereon when the tool is operational, and a dust extraction system, said system including a chamber with an entry positioned so as to receive dust and debris from the working operation, and an exit downstream from the entry and through which dust and debris O leaves the chamber, and a dust collection device secured to the C exit and wherein a visual indication means is provided as part of ,l the dust extraction system, the condition of which changes in relation to the quantity of dust and debris within the dust extraction system so as to provide an external indication of the same to the user of the power tool.

oo oo Specific embodiments of the invention are now described with reference to the accompanying drawings wherein; Figure 1 illustrates an elevation of a tool in accordance with one embodiment of the invention with a dust extraction system; Figure 2 illustrates the tool according to Figure 1 with the dust extraction system in a cleaning position; Figures 3a and 3b illustrate two embodiments of a further aspect of the invention.

Referring firstly to Figures 1 and 2 there is provided a power tool in the form of belt sander 2. The sander has an abrasive surface 4 formed by a belt of abrasive material which is driven to move as indicated by arrow 6 and, when placed on a workpiece surface a sanding effect is created. In operation dust and debris which is created by the sanding operation is induced through an entry 8 in a chamber 12 on the body 14 of the tool.

This inducement is caused partly by the movement of the belt and typically also by a fan 16 (shown in broken lines) which is driven by the motor of the tool, and which is in communication with the chamber 12. The dust passes through the chamber as indicated by arrow 10 and leaves the same via exit 18 and, in this embodiment passes into a dust collection cartridge 20 connected thereto.

b In Figure 1 the dust extraction system is shown in a normal

O

'I working condition to collect any dust which is created. However over time it is found that dust collects and can block the chamber 12 and prevent dust from reaching the cartridge 20. In accordance with the invention this problem is overcome by providing a unit 22 which defines at least one face of the chamber and which can be removed as shown in Figure 2. This 0_ allows the interior surfaces 24 of the chamber both on the body 14 and the unit 22 to be cleaned. This ensures that the S 10 chamber will not become blocked, or if it does, the same can be easily cleaned thereby ensuring efficient operation of the dust collection system and the tool. Although the unit 22 is shown in this embodiment as being held in position by screws 26 it should be appreciated that any suitable fastening means can be provided.

It is also preferred that a sealing means such as a rubber or plastic interface 28 is fitted between the unit and the housing so as to ensure that there is a seal to prevent dust from leaking externally of the chamber rather than passing into the cartridge.

As part of the system there can also be provided a visual indication means to indicate the amount of dust within the system but more typically the collection means. The visual indication means firstly includes a means for sensing the amount of dust. The particular sensing means can be of any suitable form such as a level detector which is positioned at the exit of the chamber or passes into the cartridge, or an airflow sensor which detects the speed of flow of air through the system. In any case the detection is made so as to provide an indication of the amount of dust in the system and more specifically to indicate when a predetermined level is reached such as the dust system or collection means is full or approaching full. Figures 3a and b illustrate two ways in which this condition can be b indicated. Figure 3a illustrates an electronic version wherein an Cl LED indicator 40 mounted on the housing 14 is linked to the Ssensing means and when a particular signal is received which is indicative of a particular dust amount the LED changes 5 condition such as for example, it is lit, or it changes colour.

SFigure 3b illustrates an alternative form where a mechanical 00 "flag" 42 which is linked to a sensor in the system, changes r position as the amount of dust changes and hence the sensor 10 changes. In this embodiment the flag position gradually moves Sfrom the empty condition 42' which is shown to the "full" position 42" indicated in broken lines with the movement as indicated by arrow 44.

Claims

1. A power tool, said power tool having a body and an abrasive surface and/or blade for selective positioning with Cl C 5 respect to a workpiece to perform a working operation thereon when the tool is operational, and a dust extraction system, said v-system including a chamber with an entry positioned so as to 00 0_ receive dust and debris created by the working operation and an Sexit, downstream from the entry and through which the dust and debris leaves the chamber and wherein said chamber is at least O partially defined by a unit which can be selectively removed Cl from the body to allow cleaning of the chamber.

2. Apparatus according to claim 1 wherein the chamber is defined by a wall of the body and said unit, when fixed to the body.

3. Apparatus according to claim 1 wherein the unit alone defines the chamber when fixed to the body.

4. Apparatus according to claim 1 wherein the unit is fixed to the body by fastening means.

Apparatus according to claim 4 wherein the fastening means can be used without the need for a tool.

6. Apparatus according to claim 1 wherein the chamber is in communication with a fan provided in the body to induce dust and debris through the entry and chamber.

7. Apparatus according to claim 1 wherein dust collection means can be fitted to the tool to collect dust and debris leaving the exit of the chamber.

8. Apparatus according to claim 7 wherein the tool includes an indication means, the condition of which changes when the 4 amount of dust and debris held within the collection means reaches a predetermined amount.

9. Apparatus according to claim 8 wherein the predetermined amount to cause the change in condition is such as to indicate oO oO when the chamber and/pr dust collection means is full or approaching a full condition.

Apparatus according to claim 8 wherein the indication means including a sensor which detects the predetermined amount.

11. Apparatus according to claim 11 wherein the sensor detects a reduction in airflow through the chamber.

12. Apparatus according to claim 8 wherein the indication means is generated by mechanical means.

13. Apparatus according to claim 1 wherein the tool is a sander with an abrasive sanding surface which is powered to move the same against a workpiece.

14. Apparatus according to claim 13 wherein the power tool is belt sander.

Apparatus according to claim 1 wherein the body and/or unit is provided with a transparent portion so as to allow the user to inspect the internal condition of the said chamber.

16. A power tool, said power tool having a body with an abrasive surface and/or blade for selective positioning with respect to a work piece to perform a working operation thereon 11 when the tool is operational, and a dust extraction system, said system including a chamber with an entry positioned so as to 0,0receive dust and debris from the working operation and an exit downstream from the entry and through which dust and debris leaves the chamber, and a dust collection device secured to the exit and wherein a visual indication means is provided as part of the dust extraction system, the condition of which changes in 00 00 relation to the quantity of dust and debris within the dust extraction system so as to provide an external indication of the same to the user of the power tool. CI