GB2347101A

GB2347101A - A suction device for a hand held machine tool

Info

Publication number: GB2347101A
Application number: GB9930237A
Authority: GB
Inventors: Manfred Hellbach; Karsten Blaier
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 1998-12-24
Filing date: 1999-12-21
Publication date: 2000-08-30
Anticipated expiration: 2019-12-21
Also published as: DE19860182C2; GB9930237D0; CH693873A5; GB2347101B; DE19860182A1

Abstract

A suction device 14 for a hand held machine tool 12, comprises a suction hose 18 which can be connected to a vacuum source 28 and whose suction aperture 36, or suction head, opens out in the vicinity of a tool head. The suction device is detachably connectable to the hand held machine tool, and is characterized in that the suction device can be connected to the tool via two connecting elements 20, 22, which are arranged axially spaced apart in the tool longitudinal axis 24, where each of the connecting elements is rotatable in at least one spatial direction. A control device (100, fig 2) may be associated with the suction device which varies suction capacity of the suction device as a function of a load demand at the hand held machine tool. The hand held machine tool may be a drill, hammer drill, or chisel.

Description

2347101 Suction device for a hand machine tool, more particularly a limmer

ddil Me invention relates to a suction device for a hand machine tool, more particularly a hammer drill, having the features named "in the preamble of claim 1.

State of the art Suction devices of the generic type are known. Thus, a hand-guided drilling or chiseling device is described in EP 0 470 046 Al, with which a suction device is associated, which can be detachably connected to the device. The suction device comprises a suction hose, which on the one hand can be connected to a vacuum source and on the other hand opens out via a suction head in the vicinity of a tool head. A finther suction device of this type is known from DE 35 16 099. In this case, a suction device can also be detachably connected as an accessory to a hand machine tool. Finally, an assembly device for percussive drilling machines, which can be combined with a suction device, is known from DE 3 8 03 708 Al. A further suction device for a hand machine tool is known from EP 0 558 994 Al.

Disadvantageous in all known suction devices is that a suction head, which forms a suction aperture of the suction hose, is arranged coaxial to a tool. On the one hand, this means that an unrestricted view of the tool head is impaired, and on the other hand - particularly in the case of chisel operation of a hammer drill - the suction aperture is subjected to relatively high mecharuical stress dependig on the percussion firequency of the bit.

2 Advantages of the 'invention In contrast, the suction device according to the 'invention having the features stated in claim I offers the advantage that it has a simple construction and allows for reliable suction, more particularly also during chisel operation. As a result of the fact that the suction device can be connected to the hand machine toot via two connecting elements arranged axially spaced apart along the longitudinal axis of the tool, and that each of the connecting elements is rotatable in at least one spatial direction, it is advantageously attained firstly that the suction aperture of the suction hose is arranged at a distance from the tool head radial to the tool longitudinal axis, so that ummpaired visibility of the operating site is available to the operator. Secondly, the rotatability of the connecting elements in at least one spatial direction means that mechanical stresses produced by percussive operation are absorbed by the connecting elements, i.e. can be substantially damped, so that the suction device is decoupled from direct vibrational loading.

In a preferred development of the invention, it is provided that at least the connecting element arranged in the direction of the tool head is rotatable in at least two, preferably three, spatial directions, it being possible in a ftirther preferred development to lock the connecting element in selectable rotary positions. This allows for optimal alignment of the suction head with the operating site, so that particularly good suction of any produced dust or the like is possible.

In a further preferred development of the invention, it is provided that an attachment can be fitted onto the suction head. Depending on the selected attachment, it is thus possible to access the operating site which is to be suctioned in an optimal manner.

3 Thus, different attachments with different nozzle shapes can be preferably used, which on the one hand allows for controfled suction and on the other hand allows for an increase in suction efficiency. Furthermore, it is preferable if the suction head comprises a filter. In this manner, coarse-grained material is prevented from being picked up by the suction device. Consequently, only relatively fine-grained material, whose grain size can be determined by a mesh width of a fitted filter, is picked up, Whilst coarse-grained material - which could possibly result 'in damage to the suction device - is not picked up.

In a ftirther preferred development of the invention, it is provided that a control device is associated with the suction device, which as a function of an operating mode of the hand machine tool and/or as a ftmcfion of an operating mode of the suction device can vary the suction parameters of the suction device, Thus, it can be provided "in a preferred development of the invention that the suction capacity of the suction device is variable. More particularly, the suction capacity can be reduced at intervals in such a manner that any coarse-gramied material collecting in front of a filter device falls down as a result of the effect of gravity, so that blocking of the filter device is prevented. Furthermore, it can preferably be provided that the suction capacity can be controlled as a function of a power demand of the hand machine tool. Thus, for example, the suction capacity can be throttled or switched off when the hand machine tool is idling, whilst the suction capacity can be raised in a correspondingly adapted manner when the hand machine tool is at ftffl load. In this manner, reliable suctioning of produced dust or the like is ensured at all times.

Further preferred developments of the invention will be clear from the remaining features stated 'in the subclalms.

4 Drawings The invention will be explained in further detail "in the following in embodiments with the aid of the associated drawings, in which.- Figure I is a schematic side view of a hand machine tool with suction device; Figure 2 is a circuit diagram of a control of the suction device and Figure 3 Is a circuit diagram of a second embodiment of the control of the suction device.

Description of the embodiments

Figure I is a schematic view of a hand machine tool 12 constructed as a hammer drill 10. According to further embodffinents, the hand machine tool 12 can also be formed by drilling machines, combined drilling and percussion drilling machines, hand chisels or the like. In the following, the embodiment will be explained with the aid of a hammer drill 10. Associated with the hammer drill 10 is a suction device designated "in its entirety by the reference 14. Within the firamework of the present description, the construction, ftuiction and method of operation of the hand machine tool 12, in this case the hammer drill 10, will not be dealt with in further detail, since this is generally known.

The suction device 14 comprises a suction hose 18, which can be detachably connected via two connecting elements 20 and 22 to the hammer drill 10. In this respect, the connecting elements 20 and 22 are arranged axially spaced apart in relation to a longitudinal axis 24 of a drill bit 26. The suction hose 18 is connected at one end to a vacuum source 28. The vacuum source 28 comprises a flow machine 30, for example a suction wheel which can be driven by means of an electromotor. Associated with the flow machine 30 is a filter device 32, in which suction material, which is only indicated in this case, for example dust or the like, is collected. At its other end, the suction hose 18 comprises a suction aperture 36. As shown Mi the drawing, the suction hose 18 can widen in the shape of a funnel from the vacuum source 28 "in the direction of the suction aperture 36.

The first connecting element 20 comprises a spacing element 38, at one end of which is arranged a retaining device 40 for the suction hose 18, and at the other end of which is arranged a retaining device 42 for securing to the hammer drill. The retaining device 40 is formed by a sleeve 44, which encloses the suction hose 18 'in both a positive and non- positive manner. The retaining element 42 is also formed by a sleeve 46, which is arranged on a protective sleeve 48 of the hammer drill 10. A connection between the sleeve 46 and the protective sleeve 48 can be effected, for example, by a locking connection or the like, In this manner, a detachable securing of the retaining element 38 to the hammer drill 10 is possible. The sleeve 46 is mounted so as to rotate about the longitudinal axis 24 of the hammer drill 10, as shown by the double arrow 50. Furthermore, the spacing element 38 is also rotatably 6 mounted on the sleeve 46, as shown by the double arrow 52. As a result of this type of design, it is attained that the connecting element 20 is arranged so as to be rotatable in two spatial directions, coaxial to the longitudinal axis 24 and perpendicular to the longitudinal axis 24. The swivel joint connection between the spacing element 3 8 and the sleeve 46 on the one hand and the sleeve 46 and the protective sleeve 48 on the other hand is designed 'in such a manner that said parts are freely movable at all times, i.e. the spacing element 38 and the sleeve 46 cannot be locked in position.

The connecting element 22 comprises a spacing element 54, which is formed by a first section 56 and a second section 58. The section 58 is connected at one end to a sleeve 60, which engages around the suction hose 18 in a positive and non-positive manner. At its other end, the section 58 is connected to a joint 62, so that it is rotatable according to the double arrow 64. The joint 62 is also connected to the section 56 and on the other hand with a sleeve 66, which is arranged in a positivelocking manner on the bit 26. The section 56 is articulately connected to the sleeve 66 in such a manner that the section 56 is rotatable according to the illustrated double arrow 68 in a plane lying perpendicular to the axis of rotation of the section 58. The sleeve 66 is rotatable according to the illustrated double arrow 70 about the longitudinal axis 24 of the bit and is mounted so as to be displaceable "in the axial direction of the bit 26 according to the arrow 72. As a result of the design of the spacing element 54, a rotation in three spatial directions in possible. The axial displaceability of the sleeve 66 is limited by an abutment 74, which can be locked 'in position on the bit 26, for example by means of locking means 76, for example a screw. The binge joint connections between the sections 56 and 58 as well as between the section 56 and the sleeve 66 and the sleeve 66 and the bit 26 can be locked. To this end, for example, clamping means, locking means or the like, not 7 shown "in further detail, can be provided.

The suction device 14 shown in Figure I has the following function:

By means of the connecting elements 20 and 22, the suction hose 18 can be detachably connected to the hammer drill 10. To this end, the bit 26 can be guided, for example, by the sleeve 66 and then locked in position on the hammer drill 10 by means of a clamping device. The connecting element 20 can be locked or the like onto the protective sleeve 48 by means of the sleeve 46. As a result of the spacing elements 54 adjustable in three spatial directions, the suction aperture 36 can be optimally aligned with an operating site 80, only indicated 'in the drawing. In this respect the suction aperture 36 is arranged at a radial distance from the longitudinal axis 24, so that an unrestricted view of the operating site 80 is possible. During operation of the hammer drill 10 and the suction device 14, material which is released by the bit 26 in the operating site 80, for example masonry or the like, is sucked up by the suction hose 18. This material is transported into the filter device 32 and collected. In the event of the bit 26 penetrating deeper into the operating region 80 or in the event of an operator slipping during operation, the mouth region 36 of the suction hose 18 strikes against the work piece 82 which is to be worked, so that the connecting element 22 is displaced axially on the bit 26 according to the arrow 72. Consequently, damage to the suction device, in particular the mouth region 36 of the suction hose 18, is prevented. In order to prevent a bending of the suction hose 18 in this case, the mounting of the connecting element 20, which is rotatable in two spatial planes, is provided. As a result of the compressive movement of the suction hose 18, the spacing element 38 pivots relative to the sleeve 46, which at the same time rotates about the longitudial axis 24. The connecting element 22 is prevented 8 from flying off the bit 26 by the abutment 74. In the case of bits 26 which have a diameter step or the like, for example, it is possible optionally to dispense with the abutment 74 by constructing a through aperture for receiving the bit 26 to match the sleeve 66.

A receiving region 78 of the suction aperture 36 is constructed in such a manner that attachments can be fitted onto said receiving region 78, not shown in detail here. These attachments can have a nozzle shape, for example, so that the suction aperture 36 can be moved in a controlled manner up to the operating site 80. Furthermore, the attachments can comprise filter devices, which have a selectable mesh width. In this manner, a grain size of the suction material 34 sucked up by the suction device 14 can be adjusted. Suction material having a larger grain size would then not pass through the filter at the suction aperture 36.

The rotatable mountmig of the sleeves 46, 66 means that the suction device 14 Is always arranged beneath the hammer drill 10 as a result of gravity. In this manner, visibility for an operator is not impaired. The operator therefore has a clear view of the operating site 80 at all times.

A connection of the suction hose 18 to the vacuum source 24 can either be effected in a single piece, or the suction hose 18 can be divided into sections, which can be connected via corresponding connecting elements, collars or the like.

According to further embodiments, not illustrated, the suction device 14 can also be fitted to hand machine tools 12 with rotating tools. To this end, the connections between the connecting elements 20 and 22 and the hand machine tool 12 are 9 naturally constructed in such a manner that the suction device 14 does not rotate together with the tool.

The possibilities of control of the suction device 14 win be examined in the following with the aid of Figures 2 and 3. To this end, circuit diagrams are shown in Figures 2 and 3, which illustrate a control of the suction device 14 and of the hand machine tool 12. The latter are coupled with a control device 100, which on the one hand ensures an energy supply both for the suction device 14 and for the hand machine tool 12 and on the other hand is used for the transmission and generation of control signals. According to the embodiment shown in Figure 2, the control device 100 can be connected via a single connection to a voltage supply 102, for example a socket of an electrical energy distribution network. In contrast according to the embodiment shown 'in Figure 3, the control device 100 is connected via two connecting lines to an energy supply 104 and an energy supply 106. In the case of a mains connection according to Figure 3, it is advantageously attained that a fusing of the respective circuit can be effected separately for the suction device 14 and the hand machine tool 12. In particular 'in the event of a common, simultaneous switching on of the suction device 14 and the hand machine tool 12, relatively high switching-on currents can be produced, which are thus distributed and can be better fused. In normal cases, however, the embodiment shown in Figure 2 with a common mains connection 102 w'll suff i ice.

In addition to the voltage supply, the control device 100 also allows for a control of the suction device 14 as a function of various operating parameters, in particular of the hand machine tool 12. Thus, the suction capacity of the suction device 14 can be controlled, for example by the control device 100.

Thus, it is advantageously possible to periodically (at intervals) reduce the suction capacity 'in order to allow any collected suction material, which cannot be drawn through a filter device at the suction aperture 36 into the suction device 14, to fall down as a result of gravity when the suction flow is interrupted. In this manner, the suction aperture 36 is prevented from becoming blocked.

Furthermore, it is possible to adjust the suction capacity as a function of a load demand of the hand machine tool 12. For example, if the latter is operating in idling mode, it can be assumed that there is no machinig at the operating site 80. Suction is therefore unnecessary at this point in tuine. The suction device 14 can therefore be switched off. If the hand machine tool 12 is operating at full load or partial load, a corresponding adaptation of the suction capacity of the suction device 14 can be effected. In this manner, optimum suction capacity can be adjusted at all times. The optimum is selected 'in such a manner that a suctioning of the suction material 34 Is reliably effected.

In order to attain this coupling of the suction capacity of the suction device 14 with a load demand of the hand machine tool 12, an operating element of the hand machine tool 12, which is used to determine the operating mode, can be coupled, for example, with the control device in such a manner that a corresponding signal can be picked up.

In the case of the special operation of a hammer drill 10, it is known to provide the hammer drill with control electronics, which control the load demand as a function of the contact of the bit 26 with the wall 82. If the bit 26 is pushed against the wall 82 with force, d-iis is detected and the percussive operation is subsequently controlled.

I I This control signal can be simultaneously supplied to the control device 100, which as a function of this signal adjusts the suction device 14.

To summarize, it is clear that reliable suctionmig can be combined with a hand machine too] 12 by means of a simple arrangement. As a result of the additional possibility of controlling the suction device 14 as a function of operating parameters, optimum suction behavior is obtained. The function, construction and operation of the hand machine tool 12 Is not effected by the additional arTangement of the suction device 14. The suction device 14 can be detachably connected to the hand machine tool 12, so that both the hand machine tool 12 and the suction device 14 can be used either individually or combined with various devices. It goes without saying that the length of the suction hose 18 can be selected in such a manner that it can also be connected to a central suction device or the like.

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Claims

1. A suction device for a hand machine tool, more particularly a hammer drill, with a suction hose, which can be connected to a vacuum source and whose suction aperture (suction head) opens out in the vicinity of a tool head, the suction device being detachably connectable to the hand machine tool, characterized in that the suction device (14) can be connected to the hand machine tool (12) via two connecting elements (20, 22), which are arranged axially spaced apart in the tool longitudinal axis, and each of the connecting elements (20, 22) is rotatable 'in at least one spatial direction.

2. A suction device according to claim 1, characterised 'in that at least the connecting element (22) arranged 'in the direction of the tool head is rotatable in at least two, more particularly "in three, spatial directions.

3. A suction device according to one of the preceding claims, characterised in that the connecting element (22) can be locked in selectable rotary positions.

4. A suction device accordmig to one of the preceding claims, characterised in that the connecting element (20) is rotatable in two spatial directions.

5. A suction device according to one of the preceding claims, characterised 'in that an attachment can be fitted onto the suction head (36).

6. A suction device according to claim 4, characterised 'in that nozzle attachments can be fitted onto the suction head (36).

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7. A suction device according to one of claims 5 or 6, charactenised in that a filter can be fitted onto the suction head (36).

8. A suction device according to one of the preceding claims, charactenised in that a control device (100) is associated with the suction device (14).

9. A suction device according to one of the preceding claims, charactenised in that the control device (100) varies suction parameters of the suction device (14) as a function of an operating mode of the hand machine tool (12) and/or of the suction device (14).

10. A suction device according to one of the preceding claims, characterised in that a suction capacity of the suction device (14) can be variably adjusted.

11. A suction device according to one of the preceding claims, characterised in that the suction capacity can be reduced at 'intervals.

12. A suction device according to one of the preceding claims, characterised "in that the suction capacity can be regulated as a function of a load demand at the hand machine tool (12).