DUST EXTRACTOR

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority, under 35 U.S.C. § 119, to UK Patent Application No. 18 148 71.8 filed Sep. 13, 2018.

FIELD

The present invention relates to a dust extractor for use with a drill, hammer drill or hammer, and in particular to a suction cup dust extractor.

BACKGROUND

U.S. Pat. No. 4,205,728, DE202008008561, EP2335869, EP2474385 and EP2474385 all disclose suction cup dust extractors for a drill. The present invention aims to provide an improvement in the design over those disclosed in U.S. Pat. No. 4,205,728, DE202008008561, EP2335869, EP2474385 and EP2474385.

SUMMARY

According to an embodiment, a suction cup dust extractor for a power tool is provided comprising a housing; a drill collar attached to the housing and having a drill passage formed through it; a suction chamber formed by the walls of the housing having an opening and which, in use, locates against a work piece to create a chamber; a single aperture located on the housing through which air can pass; at least one first air passage formed by the walls of the housing that connects between the drill passage and the aperture to enable air to pass from the drill passage to the aperture; and at least one second air passage formed within the housing that connects between the suction chamber and the single aperture and enables air to pass from the suction chamber to the aperture, wherein a part of the first air passage is formed by a tube.

In an embodiment, at least part of the tube passes through the suction chamber.

In an embodiment, the tube extends through the single aperture.

In an embodiment, an end of the tube that is remote from the drill passage is free standing.

In an embodiment, a connection collar is connected to the single aperture via a flexible tube, and the tube extends into the end of the flexible tube with an end of the tube terminating inside of the flexible tube.

In an embodiment, the suction chamber surrounds at least a part of the tube.

In an embodiment, the tube is straight.

In an embodiment, the tube extends perpendicularly to the drill passage.

In an embodiment, the tube extends perpendicularly to a plane of the aperture.

In an embodiment, a size of the aperture is greater than that of a cross-sectional area of the tube such that a gap is formed around the tube within the aperture which forms part of the second air passage.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the invention will now be described with reference to enclosed drawings of which:

FIG. 1 shows a perspective view of the top of the suction cup dust extractor according to a known example of suction cup extractor;

FIG. 2 shows a top view of the suction cup dust extractor;

FIG. 3 shows a bottom view of the suction cup dust extractor;

FIG. 4 shows a front view of the suction cup dust extractor;

FIG. 5 shows a vertical cross-sectional view of the suction cup dust extractor in the direction of Arrows A in FIG. 4;

FIG. 6 shows a perspective view of the underside of the suction cup dust extractor;

FIG. 7 shows a horizontal cross-sectional view of the suction cup dust extractor in the direction of Arrows C in FIG. 4.

FIG. 8 shows a perspective view of the top of the suction cup dust extractor according to a second known example of a suction cup dust extractor;

FIG. 9 shows a top view of the suction cup dust extractor;

FIG. 10 shows a bottom view of the suction cup dust extractor;

FIG. 11 shows a front view of the suction cup dust extractor;

FIG. 12 shows a vertical cross-sectional view of the suction cup dust extractor in the direction of Arrows G in FIG. 11;

FIG. 13 shows a horizontal cross-sectional view of the suction cup dust extractor in the direction of Arrows H in FIG. 11;

FIG. 14 shows a vertical cross-sectional view of the suction cup dust extractor in the direction of Arrows I in FIG. 12;

FIG. 15 shows a close up view of the venture passages;

FIG. 16 shows a vertical cross section of a dust extractor in accordance with an embodiment of the present invention;

FIG. 17 shows a vertical cross section of the dust extractor in the direction of Arrows A shown in FIG. 16;

FIG. 18 shows a vertical cross section of the dust extractor in the direction of Arrows B shown in FIG. 16;

FIG. 19 shows a vertical cross section of the dust extractor in the direction of Arrows C shown in FIG. 16; and

FIG. 20 shows an underside view of the dust extractor of FIG. 16.

DETAILED DESCRIPTION

Referring to FIGS. 1 to 7, a first known example of a suction cup dust extractor will now be described.

The suction cup dust extractor comprises a housing 10 and a drill collar 12 rigidly connected to it at the top end of the housing 10. The housing 10 comprises a skirt 14 with a bridge 16 formed on top of the skirt 14. The bridge 16 extends from the middle of the skirt 16 to the top end of the skirt 16 where it is attached to the side of the drill collar 12. The skirt 14 has a top wall 50 and side walls 52 which define a large recess 38, on the opposite side of the skirt 14 to that on which the bridge 16 is attached, which has an opening which faces away from the bridge 16.

The drill collar 12 forms a drill passage 18 which enables a cutting tool, such as a drill bit (not shown), to pass through it (direction of Arrow B in FIG. 5) to engage a work piece 20. The drill collar 12 has a longitudinal axis 22. Both the drill passage 18 and the opening of the recess 38 are orientated in the same direction.

Formed in end 26 of the bridge 16 in the middle of the skirt 14 is an aperture 24 which provides an air exit. The aperture 24 has a longitudinal axis 28 which is perpendicular to and intersects with the longitudinal axis 22 of the drill collar 12.

Formed by an internal wall 30 of the housing 10 is a first passage 32 which extends from the aperture 24 towards the drill passage 18 of the drill collar 12. The internal wall 30 also forms one of the walls which form the recess 38. Formed within the first passage 32 is a throat 34 where the diameter of the passage 32 is reduced. Two apertures 36 are formed through the wall 30 of the passage 32 at the narrowest point of the throat 34. The apertures 36 provide two passageways directly from the passage 32, through the wall 30, to the recess 38 formed by the skirt 14. Such a construction provides the operator with easy access to the apertures 36 should they become blocked with debris as the apertures 36 are exposed to the recess which is easily accessible through the opening of the recess 38.

Each of the two apertures 36 has a longitudinal axis 98, which extends along the length of the passageway formed by the aperture 36, and which intersects with the longitudinal axis 100 of the passage 32, at the point where the apertures 36 and passage 32 meet, at an angle of between 40 and 50 degrees and ideally at 45 degrees (102). The longitudinal axes 98 extends into the passage 32 from the apertures 36, in a direction parallel to the longitudinal axis 100 of the passage 32, in the same direction as the flow of air as it is sucked from the drill passage 18 through the passage 32 (direction of Arrow J in FIG. 5).

The passage 32 splits into two passages 60 between the throat 34 and the drill passage 18, each connecting with the drill passage 18 through a separate aperture 62.

An inlet air passage 64 is formed in by a frame 66 attached to the base of the drill collar 12 and operates in the same manner as that described in EP1457288. Air can pass through the inlet air passage into the drill collar 12 as shown by Arrow D.

A seal 40 locates in a groove 42 formed around the periphery of the wall of the skirt 20 on the underside of the skirt 14. When the suction cup dust extractor is placed against a work piece 20, it engages with the seal 40, the work piece 20 sealing the opening to the recess 38 to form a chamber.

An air hole 68 is provided in the wall 50 of the skirt 20 to provide a small air passage between the recess and the surrounding atmosphere. During the use of the suction cup dust extractor, the hole 68 ensures that there is a limited but constant air flow in the recess formed under the skirt 20 if the seal provides a perfect air seal with the work piece 20.

The suction cup extractor further comprises a tubular connection collar 2 which connects to a vacuum source (not shown). A rubber seal 4 is fastened inside of the connection collar 2 and which comprises two rubber rings 4 which extend radially inwards from the drill collar 12 with an aperture 8 formed through them. The rings 4 are capable of gripping onto the nozzle (not shown) of a hose (not shown) of the vacuum source. As the rings 4 are resilient, they can stretch radially outwardly, increasing the size of the apertures 8, enabling nozzles of different sizes to be used. The rings 4 would then grip the nozzle due to their resilience and frictionally hold the nozzle.

The connection collar 2 connects to the aperture 24 via a flexible tube 72. One end of the flexible tube 72 is held in a sleeve 74 formed in the connection collar 2, the other in a sleeve 76 formed in the bridge 16. The flexible tube 72 can be stretched to extend its length and move the collar 2 away from the housing 10 or be bent or twisted to allow the connection collar 2 to be moved to a range of positions relative to the aperture 24. The flexible tube 72 is made from rubber.

In use, the suction cup dust extractor is placed against a surface 70 of the work piece 20 so that the seal 40 makes contact with it. A chamber is formed when opening of the recess 38, formed by the walls 30, 50, 52, of the skirt 14 is sealed by the surface 70 of the work piece 20. The suction device is activated and air is sucked through the connection collar 2, through the flexible tube 72, through the aperture 24, through the first passage 32, through the pair of separate passages 60, through the apertures 62 and then from the drill passage 18. As air passes through the throat 34 of the first passage 32, it speeds up, causing a reduced pressure inside of the two apertures 36 due to a venturi effect. This results in the air in the recess 38 to be sucked out through the apertures 36 and into the passage 32. This causes the skirt 14 and hence the dust extractor, to be attached to the surface 70 due to the suction. The hole 68 ensures that there is a constant flow of air from the hole 68, through the recess 38, and then through the two apertures 36. The operator can then drill a hole in the surface by passing the drill bit through the drill collar 12 and drilling into the surface 70. Any debris generated during the drilling process will be sucked up into the drill passage 18 and then into passages 60. The use of two passages provides better debris clearance. The debris is then transported through the passage 32, through the aperture 24, through the flexible tube 72 and then through the connection collar 2. The hole 68 ensures that there is always air passing through the two aperture into the passage 32, thus ensuring no debris passes into the apertures 36 or the recess 38. Furthermore, the 45 degree angle between the apertures 36 and passage 32 further reduces the risks of any debris entering the apertures 36 as it sucked past the apertures 36 from the drill passage 18 to the aperture 24.

A second known example of suction cup dust extractor will now be described with reference to FIGS. 8 to 15. Where the same features are present in the second example are also present in the first example, the same reference numbers have been used. The design of the second example is the same as that for the first embodiment except for the design of three features, namely, 1) the design of the seal 40 has been altered, 2) the provision of an additional aperture to the two apertures 36, and 3) a new feature of a pressure release mechanism for the recess 38 has been added.

Firstly, the changes to the design of the seal will be described.

Referring to FIGS. 10, 12, and 14, the opening 80 of the recess 38 is planar ie the periphery of the opening 80 locates in a flat plane 82. The seal comprises a base 84 which locates in a groove 42 formed in the wall 52 of the skirt 14. The base 84 of the seal is held within the grove 42 via cover 90 which is held in place on the housing using screws (not shown). A flange 86 is attached to the base 84 which extends from the base 84 in a direction which is an oblique or small angle 88 relative to the plane 82. The flange 86 extends, in a direction parallel to the plane 82 (in the direction of Arrows M), away from the opening 80. The flange 86 extends, in a direction perpendicular to the plane 82 (in the directions of Arrows N), away from the opening 80. The outer perimeter of the flange 86 is supported by a secondary wall 92 formed on the shirt 14 of the housing 10.

Secondly, the additional aperture 94 and its inter connection with the recess will now be described.

Referring to FIGS. 12, 13 and 15, in addition to the two apertures 36 formed through the wall of the passage 32 at the narrowest point of the throat 34 to provide two direct passageways from the passage 32 to the recess 38, there is provided a third aperture 94, located between the two apertures 36, which is formed through the wall of passage 32 at the narrowest point 34 and which connects to an intermediary chamber 96 formed in the bridge 16. The intermediary chamber 96 connects to the recess 38 so that air can freely move between the intermediary chamber 96 and the recess 38. The outer wall of the intermediary chamber is formed by the external wall of the bridge 16.

Each of the two apertures 36 has a longitudinal axis 98, which extends along the length of the passageway formed by the aperture 36, and which intersects with the longitudinal axis 100 of the passage 32, at the point where the apertures 36 and passage 32 meet, at an angle of between 40 and 50 degrees and ideally at 45 degrees (102). The longitudinal axes 98 extend into the passage 32 from the apertures 36, in a direction parallel to the longitudinal axis 100 of the passage 32, in the same direction as the flow of air as it is sucked from the drill passage through the passage 32 (direction of Arrow J in FIGS. 12 and 15).

The third aperture 94 has a longitudinal axis 104, which extends along the length of the passageway formed by the aperture 94, and which intersects with the longitudinal axis 100 of the passage 32, at the point where the third aperture 94 and passage 32 meet, at an angle of between 40 and 50 degrees and ideally at 45 degrees 106. The longitudinal axis 104 extends into the passage 32 from the aperture 94 in a direction parallel to the longitudinal axis 100 of the passage 32, in the same direction as the flow of air as it is sucked from the drill passage through the passage 32 (direction of Arrow J in FIGS. 12 and 15.

The 45-degree angle between the apertures 36 and passage 32 reduces the risks of any debris entering the apertures 36 or third aperture as it sucked past the apertures 36, 94 from the drill passage 18 to the aperture 24.

The addition of the third aperture provides for increased suction in the recess 38.

Thirdly, the new feature of a pressure release mechanism for the recess 38 will now be described.

Formed in each side of the bridge 16 is a button aperture 110. Located within each button aperture 110 is a button 112. Each button 112 is mounted on an end 116 of a flexible plastic support 114 which extends around the inside of the outer wall 118 of the bridge 16 inside of the intermediary chamber 96, wrapping around the top half of the passage 32 (see FIG. 14). A leaf spring 120, which extends along the length of the plastic support 114, is surrounded by the plastic support 114, and also wraps around the top half of the passage 32. The ends 122 of the leaf spring 120 directly engage behind the ends 116 of the plastic support behind the buttons 112. The leaf spring 120 is resilient in nature and, if left in isolation would straighten up along its length. When located as shown in FIG. 14, the leaf spring 120 has been bent against its biasing force in order to be able to fit in the position as shown. The ends of the leaf spring 120 urge the ends 116 of the plastic support outwardly (in the direction of Arrow Q), urging the buttons 112 through the apertures 110.

The edges of the ends 116 of the plastic support 114 engage with the edges 124 of the walls of the bridge 16 and skirt 14 housing 10, due to the biasing force of the spring 120, to seal the apertures 110, thus preventing any air from escaping from the intermediary chamber 96 through the apertures 110.

In use, the suction cup dust extractor is placed against a surface 70 of the work piece 20 so that the seal 40 makes contact with it. A chamber is formed when opening of the recess 38, formed by the walls 30, 50, 52, of the skirt 14 is sealed by the surface 70 of the work piece 20. The suction device is activated, and air is sucked through the connection collar 2, through the flexible tube 72, through the aperture 24, through the first passage 32, through the pair of separate passages 60, through the apertures 62 and then from the drill passage 18. As air passes through the throat 34 of the first passage 32, it speeds up, causing a reduced pressure inside of the three apertures 36, 94 due to a venturi effect. This results in the air in the recess 38 to be sucked out either directly through the two apertures 36 or through the intermediary chamber 96 and the third aperture 94 and into the passage 32. This causes the skirt 14 and hence the dust extractor, to be attached to the surface 70 due to the suction. During the normal operation, the buttons 112 are in their outer most position due to the biasing force of the leaf spring 120, the edges of the ends of the plastic support engaging with the edges 124 of the of the walls of the bridge and skirt 14. In order to release the suction cup extractor from the wall, the operator has two options. Firstly, the operation can switch of the vacuum device, reducing the pressure in the recess. Alternatively, the operator can depress the bottons 112, moving the buttons 112 and the ends 116 of the plastic support 114, against the biasing force of the leaf spring 120, into the intermediary chamber 96, breaking the seal formed between the edges of the ends 116 of the plastic support 114 and the edges 124 of the of the walls of the bridge 16 and skirt 14, allowing air to be sucked in to the intermediary chamber from the air surrounding the extractor. This increases the pressure in the intermediary chamber 96 which, in turn, increases the pressure in the recess 38. As such, the amount of suction created within the recess is reduced, allowing the operator to remove the extractor from the wall.

The use of two button constructed in this manner allows the operator to pinch the buttons 112 to release the extractor and support the extractor whilst only holding the buttons 112.

An embodiment of the present invention will now be described with reference to FIGS. 16 to 20. Where the same features are present in the embodiment are also present in the second known example described above, the same reference numbers have been used. The design of the embodiment is the same as that for the second example except for the design of the aperture 24, the first passageway 38 and the drill collar 12.

In the second example, the peripheral wall of the housing 10 which surrounds the aperture 24 connects to the wall 30 of the housing 10 which forms the first passage 32. The first passage 32 extends from the aperture 24 to the drill passage 18 of the collar 12 so that air can flow from the drill passage 18 of the collar 12 to the aperture 24 through the first passage 32. Part of the wall 30 of the first passage 32 forms part of the wall 30 of the recess 38. The first passage 32 connects to the recess through two apertures 36. As such, air can only pass directly between the recess 38 and the first passage 32 through the two apertures 36. Formed in the bridge 16 is an intermediary chamber 96. Part of the wall 30 of the first passage 32 forms part of the wall 30 of the intermediary chamber 96. The first passage 32 connects to the recess 38 through a third aperture 94. As such, air can only pass directly between the intermediary chamber 96 and the first passage 32 through the third apertures 94. The intermediary chamber 96 and recess are connected so that air can flow between the intermediary chamber 96 and the recess 38. Therefore, air can only flow from the recess 38 and the first passage 32 either directly through the two apertures 36 or indirectly through the third aperture 94. As such, air can only flow from the recess 38 to the aperture 24 either directly through the two apertures 36 or indirectly through the third aperture 94, and then through the first passage. As such the amount of the air that can flow from the recess 38 to the aperture is limited by the size of the three apertures 36, 94.

In the embodiment, the aperture 24 is directly connected to the recess 38 and intermediary chamber 96. The part of the wall 30 which forms the first passage 32 which is located in close proximity to the aperture 24 is formed as a straight tube 802. The tube 802 extends through the aperture 24. The tube 802 extends perpendicularly to the plane of aperture 24 and to the drill passage 18. The diameter of the aperture 24 is greater than that of the tube 802 such that a gap 804 is formed around the tube 802 within the aperture 24. The gap 804 extends along the tube 802, between the tube 804 and the wall 806 which forms the perimeter of the aperture 24, until it engages with the recess 38 and the intermediary chamber 96. The gap 804 is in direct fluid communication with the recess 38 and intermediary chamber 96, to form a second air passage, so that air can flow directly from the recess 38 and intermediary chamber 96 through the gap 804 in order to pass through the aperture 24. The tube 804 extends into the end of the flexible tube 72, which connects between the connection collar 2 and aperture 24, with the end terminating inside of the flexible tube 72. The end of the tube 802 remote from the drill passage, inside of the flexible tube 72 is free standing i.e. it does connect to or make contact with any other part of the housing.

The intermediary chamber 96 is located above the first passage 32. The recess 38 is located below the first passage 32. The intermediary chamber 96 extends downwardly around both sides of the first passage 32, including a part of the tube 802, to merge with the recess 38 which extends upwardly around both sides of the first passage 32, including the part of the tube 802, to form a suction chamber 38, 96. As such, the suction chamber 38, 96 surrounds the part of the tube 802

During the operation of the suction cup dust extractor, the suction cup dust extractor is placed against a surface 70 of the work piece 20 so that the seal 40 makes contact with it. The suction chamber 38, 96 is sealed when opening of the recess 38 is sealed by the surface 70 of the work piece 20. The suction device is activated, and air is sucked through the connection collar 2, through the flexible tube 72, through the aperture 24, through the first passage 32, through the pair of separate passages 60, through the apertures 62 and then from the drill passage 18. In addition, air is also through the connection collar 2, through the flexible tube 72, through the aperture 24, from the suction chamber 38, 96. This results in the air in the suction chamber 38, 96 to be sucked out to hold the suction cup dust extractor to the work surface. This is in addition to air being sucked out of the recess 38 through the two apertures 36 into the first passage 32 and out of the intermediary chamber 96 through the third aperture 94 into the first passage 32. As the gap 804 is larger than the three apertures 36, 94, the reduction in air pressure in the suction chamber 38, 96 is increased.

It will be appreciated by the reader that the three apertures 36, 94 can be omitted from the design, with all the air being sucked out of the suction chamber 38, 96 through the gap 804 only.

The drill collar is releasably detachable to the housing 10 via a latch mechanism. The drill collar 12 can be detached from the housing by the depression of a button 800. EP2474385 describes such a suction cup dust extractor with a datable collar. As ability to detach the collar from the housing does not form part of the present invention, no further details of the latch mechanism are provided.

It will be appreciated by persons skilled in the art that the above embodiments have been described by way of example only and not in any limitative sense, and that various alterations and modifications are possible without departure from the scope of the invention as defined by the appended claims.

Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.

DUST EXTRACTOR

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