US20130068529A1

US20130068529A1 - Tool for Removing Drill Cores from Hammer Drill Bits

Info

Publication number: US20130068529A1
Application number: US13/425,864
Authority: US
Inventors: Thomas Hofbrucker; Jochen Meidlein
Original assignee: Hilti AG
Current assignee: Hilti AG
Priority date: 2011-03-22
Filing date: 2012-03-21
Publication date: 2013-03-21
Also published as: EP2502694A1; DE102011005903A1

Abstract

An attachment for removing a drill core from a hollow volume of a hollow drill bit, comprising an attachment sheath embodied to be arranged at an accepting shaft comprising at least one ejection element, which is embodied in the hollow volume of the hollow drill bit and designed for transferring a force upon the drill core.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to German Patent Application DE 2011 005 903.2, filed Mar. 22, 2011, and entitled “Werkzeug zur Bohrkornentfernung aus Hammerbohrkronen” (“Tool for Removing Drill Cores from Hammer Drill Bits”), which is hereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

The present invention generally relates to a device, a tool, a system, and a method for removing a drill core from a hollow drill bit, particularly a hammer drill core.
DD 277 875 A1 discloses a method for removing a drill core when drilling with core drilling devices. It provides that after the drilling and the breaking of the drill core a wedge is inserted into the drill bit, slightly inclined. Then the drill bit is pressed into the drilling gap and the drill core is clamped tightly against the interior wall by said wedge. When pulling out the drill bit the drill core is entrained and subsequently carefully tapped out of the unscrewed drill bit using a rod.
DE 10 2008 011 483 A1 shows a drill for hard materials with a shaft, with a drill bit being arranged at its end. The drill bit comprises a processing surface, which represents its face area. There is a hole in the middle of said face, with material being impressed therein during processing. The opening may penetrate the entire shaft, so that a drill core may be removed from the drill from the rear using a tappet, driver, or merely a piece of wire.
This type of removal of drill cores may only occur with a drilling tool being removed from the tool accept of the machine tool. In order to remove a hard to move or jammed drill core, a task frequently occurring in practice, in addition to the use of a driver also the use of an additional impinging tool is required to impact said driver. Here, the safety of the operator may be compromised when the impinging tool slips.
EP 1 356 883 A1 discloses a device for core drills, particularly in hollow walls for the use of hollow wall cups, comprising an ejection mechanism supported in a displaceable fashion, which during the progression of the drill shows an ejection spring, which may be stressed, in order to independently eject the drill core. However, it may occur that the spring force of the ejection spring is insufficient to independently eject the drill core. This is particularly the case when ejecting drill cores of high density, such as concrete or granite.
Thus, it may be possible to improve the process of removal of drill cores from hollow drill bits according to prior art. Particularly in case of a drill core jammed in the drill bit the user relies on a hard material to beat the hollow drill core until the drill core moves out of the hollow drill bit or, in case of a rear removal according to prior art, needs to use an impinging tool with a high risk for slipping off. On the one hand, this may damage the hollow drill bit, on the other hand it may represent a safety risk for the user.

BRIEF SUMMARY OF THE INVENTION

An attachment and method of use for removing a drill core from a hollow volume of a hollow drill bit is provided. The attachment comprises an attachment sheath embodied to be arranged at an accepting shaft comprising at least one ejection element, which is embodied in the hollow volume of the hollow drill bit and designed for transferring a force upon the drill core.

BRIEF DESCRIPTION OF THE DRAWINGS

Additional advantages, features, and details of the invention are discernible from the following description of the preferred exemplary embodiments as well as based on the drawing, which shows in a schematic illustration:

FIG. 1 is a longitudinal cross-section of an exemplary embodiment of an attachment according to a preferred embodiment;

FIG. 2 is a longitudinal cross-section of an attachment and a tool in a system according to a preferred embodiment;

FIG. 3A is a cross-section of a first variant of the embodiment of an attachment and a tool in a system;

FIG. 3B is a cross-section of a second variant of the embodiment of an attachment and a tool in a system; and

FIG. 4 is a flow chart of a preferred method for removing a drill core from a hollow drill bit.

DETAILED DESCRIPTION OF THE INVENTION

One or more of the embodiments of the present invention provide a device, a tool, a system, and a method by which a drill core may safely be removed from a hollow drill bit without being damaged.
This is attained according to the device by an attachment for removing a drill core from a hollow drill bit, relating to the tool according to a further developed tool, regarding the system by a system comprising a tool and an attachment, and regarding the method by a method for removing a drill core from the hollow drill bit.
One or more of the embodiments of the present invention is based on the thought that the method of prior art for removing the drill core may damage the hollow drill bit. In particular, in the method of prior art comprising a hammer drill bit clamped in the hammer drill the bearing of the hammer drill may also be damaged. Furthermore, one or more of the embodiments of the invention is based on the thought that a manual ejection of the drill core according to prior art should be unnecessary, to the extent possible. A device, a tool, a system, and a method for removing a drill core from a hollow drill bit should be provided with comparatively high user safety.
One or more embodiments of the invention has recognized that providing an attachment for removing a drill core from a hollow drill bit may allow a secure removal of a drill core from the hollow drill bit. For this purpose, the attachment comprises an attachment sheath to be arranged at an accepting shaft with at least one ejection element, which is embodied to engage the hollow volume of the hollow drill bit and for transferring a force upon the drill core. This way, a drill core may safely be removed from a hollow drill bit without damaging said drill bit. One or more embodiments of invention has further recognized that these advantages may be achieved with a tool according to the invention. The tool comprises: a hollow drill bit, an accepting shaft, and a clamping section, with the hollow drill bit comprising a face at the accepting side, which shows at least one opening for the engagement of an ejection element.
One or more embodiments of invention has further recognized that a method for removing the drill core from a hollow drill bit particularly designed for the use of an attachment and the tool according to the invention comprises the steps:
Arranging an attachment sheath with at least one ejection element at an accepting shaft such that the ejection element engages a hollow volume of the hollow drill bit and contacts the drill core,
Arranging an impinging part at the accepting shaft between a distant position and a contact area,
Moving the impingement part between a distant position and the contact area such that a force is transferred by the impingement part via the attachment sheath and/or the ejection element upon the drill core located in the hollow drill bit, and this way the drill core is ejected from the hollow drill bit.
This way, a drill core may safely be removed from a hollow drill bit, avoiding damage to the hollow drill bit and risks for the user.
In the method according to one or more embodiments of the invention the removal of a drill core from a hollow drill bit may occur on the one hand by a rear attachment of the attachment sheath and/or the impingement part, or also via a lateral attachment of the attachment sheath and/or the impingement part. The lateral attachment is thereby advantageous for a rapid removal of the drill core. The rear attachment allows a higher precision of guidance, and is thus suitable for the use of removing drill cores of smaller dimensions.
Within the scope of a preferred constructive further development the attachment sheath is embodied as a centering sheath. This is advantageous in that the ejecting element embodied to engage the hollow volume of the hollow drill bit and for transferring the effects of a force upon the drill core may always be brought into a position defined for engagement. Further developing this concept the ejection element may be embodied as an ejection pin.
Beneficially the attachment further comprises an impingement part for arranging and for guided movements between a distant position and an impingement area. In a first constructive further development the impingement part is embodied for transferring the impacting force upon the attachment sheath.
In an alternative constructive further development the impingement part is additionally or alternatively embodied to transfer an impacting force directly upon the ejection element. By the advantageous provision of an impingement part here higher forces may be yielded for ejecting the drill core from the hollow drill bit.
The ejection element may be connected to the attachment sheath in a form-fitting or force-fitting manner, or by substance-to-substance bonding. In this case, the force is first applied by the impingement part upon the attachment sheath and then via the ejection element upon the drill core.
The impingement part may also be embodied such that the impacting force is directly transferred to the ejection element. In this case, the attachment sheath serves as a guiding element for the ejection element or elements. The advantages of this embodiment comprise that in case of particularly hard drill cores and a perhaps accordingly high wear and tear of the ejection elements they may be exchanged relatively easily.
Within the scope of another particularly preferred constructive further development the attachment comprises a multitude of ejection elements, which are arranged in an annular fashion in the face of the attachment sheath. This is advantageous in that a force to be applied at several points may be transmitted via the ejection elements upon the drill core. The drill core may therefore be removed from the hollow drill bit in an even fashion and without canting. Accordingly, in a further constructive development the tool may comprise a hollow drill bit, comprising a multitude of penetrating openings at the side of the accept, with the penetrating openings being arranged annularly over the face area. The tool is therefore beneficially equipped together with an attachment for the use to remove a drill core.
Beneficially, the attachment sheath of the attachment comprises a slot in the sheath in the axial direction. Additionally, the impingement part may show a longitudinal slot in the axial direction. This constructive further development is advantageous such that the attachment sheath and/or the impingement part may be installed quickly and reliably even when the hollow drill bit is fastened in the hammer drill. This represents time savings in high drilling volumes.
In the following, exemplary embodiments of the invention are described in greater detail using the drawing. Said drawing shall not necessarily show the exemplary embodiments to scale, rather the drawing is schematic in order to serve explanatory purposes and/or shown in a slightly distorted form. With regards to the complementary teaching directly discernible from the drawing reference is made to the applicable prior art. Here, it must be considered that a multitude of modifications and alterations may be performed with regards to shape and detail of the embodiment, without deviating from the general idea of the invention. The features of the invention disclosed in the description, the drawing, and the claims may be used individually as well as in any arbitrary combination essential for a further development of the invention. Additionally, the scope of the invention includes any and all combinations of features disclosed in the description, the drawing, and/or the claims. The general idea of the invention is not limited to the precise form or the detail of the preferred exemplary embodiment shown and described in the following or restricted to an object which would be limited compared to the objectives disclosed in the claims. With regards to the measurement ranges stated, here too values within the limits mentioned as limits shall be considered disclosed and arbitrarily applicable and clamped. For reasons of simplification, in the following identical or similar parts or parts with an identical or similar function are marked with the same reference characters.
FIG. 1 shows an attachment 10 in a longitudinal cross-section according to a preferred embodiment. Here, the attachment 10 comprises an attachment sheath 11, an impingement part 13, and two ejection elements 12. Here, the attachment sheath 11 comprises a planar face area 14 of the sheath and a planar impingement surface 21. The two ejection elements 12 are here arranged on the face area 14 of the attachment sheath 11 and/or inserted therein via drive fit. The impingement part 13 is arranged in the axial direction in reference to the attachment sheath 10 between a distant position 23 and an impingement area 21. In the sense of the method for removing a drill core from a hollow drill bit the impingement part 13 may be guided in a distant position 23 and the impingement area 21. When the impingement part 13 hits the impact area 21, a force is transferred from the impingement part to the attachment sheath 11, in order to be transferred via the ejection elements 12 upon the drill core, not shown. By a repeated movement of the impingement part 13 between the distant position 23 and the impact area 21 subsequently an intermittent force is applied upon the drill core.
FIG. 2 shows a system 100 comprising the attachment of FIG. 1 and a tool 80. The tool 80 comprises here a hollow drill bit 70 with an accepting shaft 72 and a clamping area 76. A drill core 90 is present in the hollow volume 71 of the hollow drill bit 70. The hollow drill bit 70 comprises here a face area 18 at the accepting side and two penetrating openings 75 at the accepting side, which are embodied as penetrating bores. The attachment sheath 11 is arranged at the accepting shaft 72 such that the two ejection elements 12 penetrate through the penetrating openings 75 embodied in as penetrating bores and contact the drill core 90. The fittings between the penetrating openings 75 and the ejecting element 12 shows play, here. As already discernible from FIG. 1, the impingement part 13 is arranged between a distant position 23 and an impact area 21 on the attachment sheath 11. The accepting shaft 72 comprises a clamping area 76 for mounting in a hammer drill.
FIGS. 3A and 3B show a cross-section A-A, with its progression being illustrated in FIG. 2. FIG. 3B shows here an embodiment shown as a variant of FIG. 2, thus here the progression A-A of the cross-section shown in FIG. 2 shall only be considered an example. In the embodiment of a system 100 shown in FIG. 3A the attachment sheath 11 and the impingement part 13 are free from slots. According to the method, here the attachment sheath 11 and the impingement part 13 are arranged by being plugged on from the rear. As discernible from the cross-sectional illustration the attachment sheath 11 completely covers the accepting shaft 72 here, and itself in turn is completely covered by the impingement part 13. The fittings between the attachment sheath 11 and the accepting shaft 72 and/or the attachment sheath 11 and an impingement part 13 are here fittings with play. FIG. 3B shows a cross-section of another embodiment, namely a system 100′. The attachment sheaths 11 here comprises one sheath slot 15 each in the axial direction in reference to the attachment sheath 11. The two impingement parts 13 each show a longitudinal slot 17 in the axial direction of the impingement part 13. FIG. 3B shows here in the view (i) the alignment of the attachment sheath 11 and the impingement part 13 immediately after their lateral fastening on the accepting shaft 72 by way of being plugged on. In the view (ii) for the above-described embodiment, FIG. 3B shows an arrangement with an impingement part 13 distorted about the longitudinal axis. The impingement part 13 is here arranged such that the sheath slot 15 located in the attachment sheath 11 is essentially covered by the wall of the impingement part 13. This way it may be effectively prevented at least that the attachment sheath laterally falls off during the operation of the attachment.
In a flow chart FIG. 4 illustrates a method for removing a drill core from a hollow drill bit. In the cross-section 201 here first an ejection element 12 comprising an attachment sheath 11 is arranged at an accepting shaft 72 of a tool 80 also comprising a hollow drill bit 70 and a clamping section 76, fastened by way of laterally being plugged on. In the appropriate position the ejection element 12 engages a hollow volume 71 of the hollow drill bit 70 and contacts the drill core 90. In step 202 an impingement part 13 is plugged laterally upon the attachment sheath 11 between a distant position 23 and an impact area 21. In step 203 the impingement part 13 between the distant position 23 and the impact area 21 is moved such that a force is first applied by the impingement part 13 upon the attachment sheath 11 and then by the attachment sheath 11 via the ejection element 12 transferred upon the drill core 90 located in the hollow drill bit 70, thus ejecting the drill core from the hollow drill bit 70. The step 203, moving the impingement part 13 between the distant position 23 and the impact area 21, is performed at least one, usually several times.
While particular elements, embodiments, and applications of the present invention have been shown and described, it is understood that the invention is not limited thereto because modifications may be made by those skilled in the art, particularly in light of the foregoing teaching. It is therefore contemplated by the appended claims to cover such modifications and incorporate those features which come within the spirit and scope of the invention.

Claims

1. An attachment for removing a drill core from a hollow volume of a hollow drill bit, said attachment comprising

an attachment sheath embodied for fastening at an accepting shaft having at least one ejection element, which is embodied to engage the hollow volume of the hollow drill bit and for transferring a force upon the drill core.

2. An attachment according to claim 1, wherein the attachment sheath is embodied as a centering sheath.

3. An attachment according to claim 1, wherein the ejection element is embodied as an ejection pin.

4. An attachment according to claim 1 wherein in an impingement part to be arranged and moved in a guided fashion between a distant position and an impact area.

5. An attachment according to claim 4, wherein the impingement part is embodied to transfer a force impacting the attachment sheath.

6. An attachment according to claim 4, wherein the impingement part is embodied to transfer an impacting force upon the ejection element.

7. An attachment according to claim 1 wherein the attachment comprises a multitude of ejection elements arranged annularly on a face area of the attachment sheath.

8. An attachment according to claim 1 wherein the attachment sheath comprises a sheath slot in the axial direction.

9. An attachment according to claim 4, wherein the impingement part comprises a longitudinal slot in the axial direction.

10. A tool comprising:

a hollow drill bit;

an accepting shaft; and

a clamping area, wherein the hollow drill bit comprises a face area at the accepting side, which shows at least one penetrating opening for the engagement of an ejection element.

11. A tool according to claim 10, wherein the hollow drill bit comprises a multitude of penetrating openings at the accepting side, with the penetrating openings being arranged annularly on the facial area.

12. A system including:

a hollow drill bit;

an accepting shaft;

a clamping area, wherein the hollow drill bit comprises a face area at the accepting side, which shows at least one penetrating opening for the engagement of an ejection element; and

13. The system of claim 12 wherein in that the hollow drill bit comprises a penetrating hole, which is formed such that an ejection element may engage a hollow volume of the hollow drill bit in order to transfer an impacting force upon a drill core.

14. A method for removing a drill core from a hollow drill bit, said method comprising:

arranging an attachment sheath with at least one ejection element at an accepting shaft so that the ejection element engages a hollow volume of a hollow drill bit and contacts a drill core;

arranging an impingement part at the attachment sheath between a distant position and an impact area; and

moving the impingement part between the distant position and the impact area such that a force of the impingement part is transferred via the attachment sheath and/or the ejection element upon the drill core located in the hollow drill bit and thus the drill core is ejected from the hollow drill bit.

15. A method according to claim 14, wherein the arrangement of at least one of the attachment sheath and the impingement part occurs by laterally plugging it on.

16. A method according to claim 14, wherein the arrangement of at least one of the attachment sheath and the impingement part occurs by way of plugging on from the rear.