SUCTION HEAD

Abstract

Suction head for sucking up drilling debris accumulating during the drilling of a borehole into a subsurface (32), comprising a housing (12) which has a drill bit holder (28) for inserting a drill bit (30), a suction channel (36) leading from the drill bit holder (28) to a suction connection (38) for a suction device, and a suction hood (60) which is circumferentially surrounded by a sealing element (56) and which can be placed against the subsurface (32) with the sealing element (56) interposed, said suction hood being in flow connection with the suction channel (36), characterized in that a check valve (72) opening in the direction of the suction channel (36) is arranged in the flow path between the suction hood (60) and the suction channel (36), and in that the suction hood (60) has a ventilation opening (76) which can be selectively opened and closed by means of a ventilation valve (78), wherein the housing (12) has a ventilation chamber (46),which is in flow connection with the surroundings of the housing (12) via at least one inlet opening (92) and with the suction hood (60) via the ventilation opening (76), and the suction channel (36) has two channel arms (42, 44) between which the ventilation chamber (46) is arranged.

Description

[0001] The invention relates to a suction head for sucking away drilling debris produced when drilling into a subsurface, comprising a housing having a drill bit holder for inserting a drill bit, a suction channel leading from the drill bit holder to a suction connection for a suction device, and a suction hood surrounded in the circumferential direction by a sealing element and which can be placed against the subsurface with the sealing element interposed, said suction hood being in flow connection with the suction channel.

[0002] Such suction heads are known from utility model DE 20 2008 008 561 U1. They can be used to suck up drilling debris, i.e. drilling material and drilling dust, that accrues when drilling into a substrate. For this purpose, the suction heads have a housing that has a drill bit holder for inserting a drill bit and a suction channel leading from the drill bit holder to a suction connection. A suction device, such as a vacuum cleaner, can be connected to the suction connection. The suction head can be placed against the substrate so that the drill bit holder takes up a position at the desired drilling location. The suction head has a suction hood that is surrounded by a sealing element and is in flow connection with the suction channel. It can be placed against the substrate with the sealing element interposed.Under the influence of the suction flow provided by the suction device, a negative pressure is created within the suction hood, which presses the suction head against the negative pressure. Therefore, the user does not need to hold the suction head in place with one hand while drilling; instead, the suction head adheres automatically to the substrate under the influence of the negative pressure in the suction hood.

[0003] In order for the suction head to adhere to the negative pressure during drilling, it is essential that there is a sufficient negative pressure at all times in the suction hood. However, it cannot be guaranteed in all cases that the suction device connected to the suction connection will provide an uninterrupted suction flow that ensures the negative pressure required for the suction head to adhere. For example, vacuum devices are known that have a filter that is cleaned from time to time with the help of a cleaning device. In this case, air is briefly blown through the filter in the opposite direction to the flow direction prevailing during normal suction operation, causing dirt particles to detach from the filter. This can lead to pressure fluctuations in the suction duct, with the risk that the negative pressure prevailing in the suction hood will weaken so much that the suction head detaches from the substrate.

[0004] The object of the present invention is therefore to further develop a suction head of the type mentioned at the outset in such a way that the risk of the suction head becoming detached from the substrate due to pressure fluctuations prevailing in the suction channel is reduced.

[0005] This object is achieved by a suction head having the features of patent claim 1.

[0006] If, in the suction head according to the invention, the negative pressure provided by the suction device within the suction channel briefly decreases, so that the negative pressure in the suction hood is greater than the negative pressure in the suction channel, the check valve automatically returns to its closed position and thereby interrupts the flow connection to the suction channel. The negative pressure prevailing in the suction hood is thus essentially maintained and it is ensured that the suction head does not detach from the substrate. If the negative pressure in the suction channel subsequently increases again, so that the negative pressure in the suction channel is greater than the negative pressure in the suction hood, the check valve automatically returns to its open position and re-establishes the flow connection to the suction hood.

[0007] According to the invention, the suction hood has a ventilation opening that can be selectively opened and closed by means of a ventilation valve. By opening the ventilation valve, the suction hood can be ventilated to allow the suction head to be removed from the substrate after drilling. The ventilation valve is conveniently manually operated.

[0008] Preferably, the ventilation valve is designed as a spring-loaded check valve which automatically assumes its closed position under the action of a return spring and can be moved by the user into an open position against the action of the return spring.

[0009] According to the invention, the housing of the suction head has a ventilation chamber that is fluidly connected to the housing's surroundings via at least one inlet opening and to the suction hood via the ventilation opening. The ventilation chamber is fluidly separated from the suction duct. Therefore, there is no risk of drilling debris from the suction duct entering the suction hood via the ventilation opening. Instead, the suction hood is ventilated with external air, which can enter the ventilation chamber via the at least one inlet opening and from there via the ventilation opening into the suction hood, provided the ventilation valve is in the open position.

[0010] To achieve a particularly compact design of the suction head, the suction channel has two channel arms, between which the ventilation chamber is arranged. A first channel arm can, for example, extend along a first side of the ventilation chamber, and a second channel arm can extend along a second side of the ventilation chamber, with the two sides advantageously being opposite each other.

[0011] In an advantageous embodiment of the suction head according to the invention, the check valve is designed as a diaphragm valve. This allows for a particularly compact design.

[0012] It is advantageous if the suction channel is in flow connection with the suction hood via a suction chamber, wherein a suction opening via which the suction hood is connected to the suction chamber can be opened and closed by means of the check valve. In such a configuration, a suction chamber is arranged between the suction hood and the suction channel, through which the flow path from the suction hood to the suction channel leads. The suction chamber is connected on the one hand to the suction channel and on the other hand to the suction hood. The flow connection from the suction chamber to the suction hood is via a suction opening, and the check valve is positioned at the suction opening. The provision of the suction chamber has the advantage that drilling dirt that is sucked away from the drill chuck via the suction channel cannot easily reach the check valve and via this into the suction hood.

[0013] The check valve, preferably a diaphragm valve, is advantageously positioned within the suction chamber. The provision of the check valve therefore does not result in a reduction in the interior space of the suction hood, and the check valve is protected from mechanical interference that could occur when the suction hood is exposed to negative pressure.

[0014] It is particularly advantageous if the suction chamber is connected to the extraction duct via a connecting duct. Providing the connecting duct further reduces the risk of drilling debris reaching the check valve and through the suction opening into the suction hood in the event of a brief drop in the negative pressure in the extraction duct.

[0015] It is particularly advantageous if the connecting channel is offset from the suction opening, as this creates a kind of flow labyrinth in the suction chamber, which further reduces the risk of drilling dirt accidentally getting from the suction channel into the suction hood.

[0016] The connecting channel advantageously extends into the suction chamber so that it does not form a flow obstacle within the suction channel.

[0017] As already mentioned, the sealing element ensures that a negative pressure develops inside the suction hood when it is placed against the substrate and vacuumed. It is advantageous if the sealing element is elastically compressible and protrudes at least 3 mm over the edge of the suction hood when unloaded. A projection of at least 5 mm has proven to be particularly advantageous. If a negative pressure develops in the suction hood due to the suction flow provided by the vacuum cleaner, the suction hood is pressed against the substrate and the sealing element is compressed, reducing the volume of the interior of the suction hood. If, for example, the negative pressure in the suction duct decreases due to the filter cleaning process of the vacuum cleaner, the check valve automatically changes from its open position to its closed position.During the transition from the open to the closed position, the initially brief flow connection from the extraction duct to the suction hood also causes a slight reduction in the negative pressure prevailing inside the suction hood. Due to the elasticity of the sealing element, this causes it to expand, slightly increasing the volume of the interior of the suction hood. This increases the negative pressure prevailing in the suction hood and accelerates the transition of the check valve to its closed position. The provision of the elastically compressible sealing element, which protrudes at least 3 mm, in particular at least 5 mm, beyond the edge of the suction hood, thus further reduces the risk of the suction hood accidentally becoming detached from the substrate.

[0018] It is advantageous if the ventilation chamber is essentially triangular in shape when viewed from above.

[0019] As mentioned at the beginning, a suction device can be connected to the suction connection. The suction connection is advantageously designed in the form of a suction nozzle, to the free end of which a suction line of the suction device can be connected, for example a suction hose. The suction line is in flow connection with a suction unit of the suction device, so that a suction flow develops in the suction line and the suction duct under the action of the suction unit. The suction line connected to the suction nozzle exerts a tilting moment on the suction head due to its weight. To prevent the suction head from becoming detached from the substrate under the effect of the tilting moment, it is advantageous if the sealing element that surrounds the suction hood in the circumferential direction has a straight sealing element section below the suction nozzle, oriented transversely to a longitudinal axis of the suction nozzle.The straight sealing element section forms a support that counteracts the detachment of the suction head from the substrate due to the tilting element exerted by the suction line.

[0020] In an advantageous embodiment, the housing of the suction head has an upper housing part and a lower housing part, which together form the drill holder and at least one inlet section of the suction channel directly adjoining the drill holder.

[0021] The drill holder can be designed in the manner of a passage or channel with a peripheral wall that completely surrounds the inserted drill in the circumferential direction, but it can also be U- or C-shaped in plan view and form a type of fork that only partially surrounds the drill in the circumferential direction.

[0022] The upper housing part is preferably mechanically connected to the lower housing part. For example, the upper housing part can be locked or screwed to the lower housing part.

[0023] The lower housing section preferably forms the suction hood and a receptacle for the sealing element. The suction hood can, for example, have an inner edge and an outer edge, which form the receptacle for the sealing element between them.

[0024] Preferably, the housing base is designed in a plate-like configuration in some areas. This facilitates the manufacture of the housing base and enables a particularly compact design of the suction head.

[0025] In an advantageous embodiment, the lower housing part and the upper housing part together form the ventilation chamber through which the suction hood can be ventilated if necessary.

[0026] In an advantageous embodiment, the ventilation chamber is penetrated by a valve tappet of a ventilation valve. The valve tappet advantageously extends into the suction hood and carries a valve disc within the suction hood. When the ventilation valve is in the closed position, the valve disc closes a ventilation opening extending between the ventilation chamber and the suction hood. The valve tappet can be moved into an open position spaced apart from the ventilation opening by means of the valve tappet, counter to the action of a return spring.

[0027] The return spring of the ventilation valve advantageously surrounds the valve tappet in the circumferential direction and is supported on the one hand on the lower part of the housing and on the other hand on the valve tappet or an actuating element connected to the valve tappet, for example a pressure plate.

[0028] In a preferred embodiment of the invention, the suction head has an intermediate part arranged between the upper housing part and the lower housing part, which defines at least one longitudinal section of the suction channel.

[0029] The intermediate part can be designed as a hollow body.

[0030] It is particularly advantageous if the intermediate part forms two channel arms of the suction channel, between which the ventilation chamber is arranged.

[0031] As already mentioned, it is advantageous if the flow connection from the suction channel to the suction hood is established via a suction chamber. In this case, it is advantageous if the intermediate part and the housing base define the suction chamber. For example, the intermediate part can form a ceiling wall, and the housing base can form a floor wall of the suction chamber. Side walls of the suction chamber can be formed by the intermediate part and / or the housing base.

[0032] As already mentioned, the suction connection is preferably designed as a suction nozzle. It is advantageous if the upper part of the housing forms the suction nozzle.

[0033] The following description of an advantageous embodiment of the invention serves to explain it in more detail in conjunction with the drawings. They show: Fig. 1: A perspective view of an advantageous embodiment of a suction head according to the invention; Fig. 2: a front view of the suction head from Fig. 1; Fig. 3: a sectional view of the suction head along the Fig. 3-3 in Fig. 2; Fig. 4: a sectional view of the suction head according to Fig. 3 during use of the suction head to vacuum up drilling debris; Fig. 5: an enlarged view of detail A from Fig. 3; Fig. 6: an enlarged view of detail B from Fig. 3; Fig. 7: a sectional view along the line 7-7 in Fig. 3; Fig. 8: a perspective view of the suction head in the form of an exploded view.

[0034] The drawing schematically shows an advantageous embodiment of a suction head according to the invention, which is designated overall by the reference numeral 10. The suction head has a housing 12, which has an upper housing part 14 and a lower housing part 16 and an intermediate part 18 arranged between the upper housing part 14 and the lower housing part 16. The housing 12 has two straight, obliquely aligned longitudinal sides 20, 22, which are connected to one another via an end face 24 and a rear side 26. As can be seen in particular from Fig. As is clear from Figure 7, the rear side 26 is aligned parallel to the front side 24, although the front side 24 has a shorter extension than the rear side 26.

[0035] Adjacent to the end face 24, the housing 12 has a drill receptacle 28, which is formed by the upper housing part 14 and the lower housing part 16 and, in the illustrated embodiment, forms a circular passage in plan view. During use of the suction head 10, a Fig. 4 shown drill 30 can be inserted into the drill holder 28 to drill a hole in a Fig. 4 shown background 32.

[0036] A suction channel 36 is connected to the drill bit holder 28 via a lateral opening 34 of the drill bit holder 28 within the housing 12. The suction channel 36 extends from the drill bit holder 28 through the housing 12 to a suction connection 38, which in the illustrated embodiment is designed as a suction nozzle 40. The suction nozzle 40 is formed by the housing upper part 14.

[0037] Within the housing 12, the suction nozzle 40 is adjoined by the intermediate part 18, which is designed as a hollow body and forms a longitudinal section 41 of the suction channel 36. This is particularly evident from Fig. 7. At a distance from the suction nozzle 40, the intermediate part 18 forms a first channel arm 42 and a second channel arm 44, which extend in the direction of the drill bit holder 28. A ventilation chamber 46 is arranged between the two channel arms 42, 44 within the housing 12. An end section 48 of the suction channel 36 adjoins the two channel arms 42, 44. The end section 48 extends to the opening 34 of the drill bit holder 28 and is formed jointly by the housing upper part 14 and the housing lower part 16.

[0038] The lower housing part 16 is, with the exception of an area surrounding the drill holder 28, essentially plate-shaped and forms a bottom wall 50, from which an inner edge 52 and an outer edge 54 arranged at a distance from the inner edge 52 project downwards in the direction facing away from the upper housing part 14. The inner edge 52 and the outer edge 54 form a receptacle 55 between them, in which a sealing element in the form of a sealing ring 56 is arranged, which projects outwards beyond the inner edge 52 and the outer edge 54. In the unloaded state, as in Fig. As shown in Figure 3, the sealing ring 56 has a projection 58 of at least 3 mm, preferably 5 to 6 mm. The sealing ring 56 is elastically compressible.

[0039] The bottom wall 50, in combination with the inner edge 52, forms a suction hood 60, which can be applied to the substrate 32 with the sealing ring 56 in between. This is Fig. 4 clearly.

[0040] The bottom wall 50 has a suction opening 62, via which the suction hood 60 is in flow connection with a suction chamber 64. The suction chamber 64 is formed by the bottom wall 50 of the lower housing part 16 and by the intermediate part 18. For this purpose, the intermediate part 18 has a chamber wall 66 oriented perpendicular to the bottom wall 50, which forms a side wall of the suction chamber 64. A ceiling wall 68 of the suction chamber 64 is also formed by the intermediate part 18. A connecting channel 70 opens into the ceiling wall 68, extends within the suction chamber 64 and via which the suction chamber 64 is in flow connection with the suction channel 36.

[0041] The suction opening 62 can be closed by means of a check valve, which in the illustrated embodiment is designed as a diaphragm valve 72 and is arranged within the suction chamber 64 on the bottom wall 50. This is particularly evident from Fig. 5. The diaphragm valve 72 opens in the direction of the suction channel 36, so that the suction hood 60, after it has been placed against the substrate 32, can be subjected to negative pressure via the suction opening 62, the suction chamber 64, the connecting channel 70, and the suction channel 36. The diaphragm valve 72 automatically assumes its open position. If the negative pressure in the suction channel 36 is briefly reduced, the diaphragm valve 72 automatically returns to its closed position, interrupting the flow connection between the suction chamber 64 and the suction hood 60.

[0042] As already mentioned, the ventilation chamber 46 is arranged between the two channel arms 42, 44 of the intermediate part 18. The ventilation chamber 46 is circumferentially bounded by an annular wall 74 which is essentially triangular in plan view. This is Fig. 7. The annular wall 74 projects upward from the bottom wall 50 of the lower housing part 16 toward the upper housing part 14. The bottom wall 50 has a ventilation opening 76, which enables a flow connection from the ventilation chamber 46 to the suction hood 60 and which can be closed by a ventilation valve 78.

[0043] The ventilation valve 78 has a valve stem 80 that extends through the ventilation chamber 46 and extends into the suction hood 60 with a lower end portion 82. At the lower end portion 82, the valve stem 80 carries a valve plate 84, by means of which the ventilation opening 76 can be selectively opened and closed.

[0044] At its end facing away from the valve plate 84, the valve tappet 80 carries an actuating element in the form of a pressure plate 86, which in the Fig. 3 and Fig. 4, the ventilation valve 78 is immersed in a through opening 88 of the upper housing part 14, so that it is accessible to the user from the outside.

[0045] The valve stem 80 is surrounded within the ventilation chamber 46 by a return spring 90, which is supported on the one hand by the pressure plate 86, which is integrally connected to the valve stem 80, and on the other hand by the base wall 50. Under the action of the return spring 90, the valve stem 80 is pushed upwards until the valve plate 84 rests against the ventilation opening 76 and closes it. Contrary to the action of the return spring 90, the user can press the valve stem together with the pressure plate 86 downwards towards the base wall 50, so that the valve plate 84 takes up a distance from the ventilation opening 76 and thereby opens it. This is Fig. 6 clearly.

[0046] To the side of the through-opening 88, the upper housing section 14 has several inlet openings 92, through which the ventilation chamber 46 is permanently connected to the surroundings of the housing 12. External air can thus flow into the ventilation chamber 46 through the inlet openings 92. If the user actuates the ventilation valve 78, the external air can reach the suction hood 60 via the ventilation opening 76, thus ventilating it.

[0047] To extract drilling dirt, a suction line, for example a suction hose 94, can be connected to the suction nozzle 40, as shown in Fig. 4. The suction hose 94 is in flow connection with a suction unit of a known suction device, so that a suction flow can be formed by the suction unit, which extends from the drill holder 28 via the suction channel 36 to the suction nozzle 40 and then via the suction hose 94 to the suction unit. The suction hose 94 exerts a tilting moment on the suction head 10. In order to counteract this tilting moment, a sealing ring section 96 running parallel to the rear side 26 of the housing 12 is designed in a straight line and oriented perpendicular to a longitudinal axis 98 of the suction nozzle 40. This is particularly evident from the Fig. 4 and Fig. 8 clearly.

[0048] To drill a hole in the substrate 32, the suction head 10 can be positioned on the substrate 32. By connecting the suction head 10 to a suction device, a suction flow can be created in the suction channel 36, as explained above. Since the suction channel 36 is in flow connection with the suction hood 60 via the suction chamber 64 and the suction opening 62, a negative pressure is created in the suction hood 60. This results in the suction head 10 being pressed against the substrate 32, compressing the sealing ring 56 and sealing the interior of the suction hood 60. The suction head 10 is automatically held on the substrate 32 under the effect of the negative pressure prevailing in the suction hood 60, so that the user has both hands free to drill a hole in the substrate.If there is a brief reduction in the negative pressure within the suction channel 36, for example due to filter cleaning in the suction device, the diaphragm valve 72 automatically changes from its open position to its closed position, thereby interrupting the flow connection between the suction channel 36 and the suction hood 60. This ensures that a brief reduction in the negative pressure in the suction channel 36 does not result in a corresponding reduction in the negative pressure within the suction hood 60, so that the suction head 10 reliably adheres to the substrate 32 even during brief interruptions in the suction flow. The provision of the diaphragm valve 72 also ensures that no drilling debris can enter the suction hood 60 from the suction channel 36 in the event of an interruption in the suction flow.The entry of drilling debris into the suction hood 60 is also prevented by the provision of the connecting channel 70 and the suction chamber 64, which in combination with the suction opening 62 form a flow labyrinth and reduce the risk of drilling debris entering the suction hood 60.

[0049] If the user wishes to release the suction head from the substrate 32 after a drilling operation, he or she actuates the ventilation valve 78. External air can then flow into the suction hood 60 via the inlet openings 92, the ventilation chamber 46 and the ventilation opening 76, so that pressure equalization takes place.

Claims

[1] Suction head for sucking up drilling dirt accumulating when drilling into a substrate (32), with a housing (12) which has a drill holder (28) for inserting a drill (30), a suction channel (36) leading from the drill holder (28) to a suction connection (38) for a suction device and a suction hood (60) which is surrounded in the circumferential direction by a sealing element (56) and which can be placed on the substrate (32) with the sealing element (56) interposed, and which is in flow connection with the suction channel (36), characterized byin that a check valve (72) opening in the direction of the suction channel (36) is arranged in the flow path between the suction hood (60) and the suction channel (36), and in that the suction hood (60) has a ventilation opening (76) which can be selectively opened and closed by means of a ventilation valve (78), wherein the housing (12) has a ventilation chamber (46) which is in flow connection with the environment of the housing (12) via at least one inlet opening (92) and with the suction hood (60) via the ventilation opening (76), and the suction channel (36) has two channel arms (42, 44) between which the ventilation chamber (46) is arranged. [2] Suction head according to claim 1, characterized by that the check valve is designed as a diaphragm valve (72). [3] Suction head according to claim 1 or 2, characterized bythat the suction channel (36) is in flow connection with the suction hood (60) via a suction chamber (64), wherein a suction opening (62) can be opened and closed by means of the check valve (72), via which the suction hood (60) is connected to the suction chamber (64). [4] Suction head according to claim 3, characterized by that the check valve (72) is arranged in the suction chamber (64). [5] Suction head according to claim 3 or 4, characterized by that the suction chamber (64) is connected to the suction channel (36) via a connecting channel (70). [6] Suction head according to claim 5, characterized by that the connecting channel (70) projects into the suction chamber (64). [7] Suction head according to one of the preceding claims, characterized by that the sealing element (56) is elastically compressible and, in the unloaded state, projects at least 3 mm beyond an edge (52) of the suction hood (60). [8] Suction head according to one of the preceding claims, characterized bythat the suction connection (38) is designed as a suction nozzle (40), to the free end of which a suction line (94) can be connected. [9] Suction head according to claim 8, characterized by that the sealing element (56) below the suction nozzle (40) has a rectilinear sealing element section (96) aligned transversely to a longitudinal axis (98) of the suction nozzle (40). [10] Suction head according to one of the preceding claims, characterized by that the housing (12) has an upper housing part (14) and a lower housing part (16), which together form the drill holder (28). [11] Suction head according to claim 10, characterized by that the upper housing part (14) and the lower housing part (16) together form an end section (48) of the suction channel (36) directly adjoining the drill holder (28). [12] Suction head according to claim 10 or 11, characterized by that the lower housing part (16) forms the suction hood (60). [13] Suction head according to claim 10, 11 or 12, characterized by that the housing lower part (16) forms a receptacle (55) for the sealing element (56). [14] Suction head according to one of claims 10 to 13, characterized by that the lower housing part (16) and the upper housing part (14) together form the ventilation chamber (46). [15] Suction head according to one of claims 10 to 14, characterized by that the suction head (10) has an intermediate part (18) arranged between the upper housing part (14) and the lower housing part (16), which forms at least one longitudinal section of the suction channel (36). [16] Suction head according to claim 15, characterized by that the intermediate part (18) and the lower housing part (16) define the suction chamber (64). [17] Suction head according to one of claims 10 to 16, characterized by that the upper housing part (14) forms the suction nozzle (40).

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