DE8800476U1 - Guide and drilling depth stop device for hand drills - Google Patents

Description

blPL-ING, PETER OTTE LAWYER'' \ \ > D-7250 Leonberg

Representative at the European Patent Attorney Tiroler Straße

2110'ot/m
10.12.1987

company Kress-elektrik GmbH & Co. Elektromotorenfabrik, Hechinger Straße, 7457 Bisingen

Guide and drilling depth stop device for hand drills

State of the art

The invention is based on a guide and drilling depth stop device for hand drills according to the preamble of claim 1.

It is common practice to provide a drilling depth stop in the form of a simple rod on hand drills, which can be adjusted in position, for example, by means of a through hole in a handle that is additionally attached to the drill. The handle has a first large receiving opening, which is suitable as a standard opening to enclose the neck of the drill; by turning the handle, the (additional) handle can then be firmly connected to the drill by tightening a screw connection. At the same time, the through hole for the drilling depth rod closes so that it is then firmly in place. The drilling depth rod can have a scale and is set so that after the specified drilling depth has been reached, it hits the base in a parallel alignment to the drilling or other processing tool. This enables further drilling and, if necessary,

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if unwanted drilling of the object to be processed is prevented.

It is also known in another area of craft technology, namely with so-called routers, to equip the router with a clamping bracket or to insert its base body into a separate clamping bracket device and screw it in. This clamping bracket, which has handles on both sides, forms a one-piece guide tube on one side, in which another tube slides under spring preload, which has a plate-like base at its free end, on which further setting and adjustment devices are arranged (see brochure Electronic router Of E 50C with parallel stop - Metabo).

When working with hand drills, it is not easy even for experienced users to drill the hole exactly vertically, although this is desirable for many other reasons and may even be necessary. The problem mentioned above also occurs again and again that the force of pressure means that the material being worked on is often drilled straight through when all you wanted to do was drill a blind hole. The well-known rod-shaped drilling depth stop is only of little help here, since if the screw is not tightened completely, which can happen particularly with frequent adjustments, the stop can be pushed over and, when drilling at an angle, it may not hit the surface of the workpiece until it has already been drilled through. This is because the rod-shaped drilling depth stop can only be positioned on one side of the hand drills, parallel to the drill.

Another inconvenience when working with hand drills

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machines, especially when drilling holes in concrete or brick walls, is the fine drilling dust that is generated, which makes it necessary to thoroughly clean the workplace after the work has been completed.

The invention is based on the object of creating a device for hand drills which simultaneously enables the hand drill to be aligned with its base, thus forming a guide means for vertical drilling and furthermore provides a safe, non-overpressible drilling depth stop, with an overall very simple, cost-effective design and problem-free application.

Advantages of the invention

The invention solves this problem with the characterizing features of the main claim and has the advantage that the two tubes, which can be telescoped into one another under spring preload and form the guide and drilling depth stop device according to the invention, with a simple structure and easy attachment to the drilling machine, perfectly prevent the possibility of tilting or diagonal drilling with the hand drill equipped in this way thanks to the wide support basket resting over a large area on the base, and on the other hand a stop accurate to the millimeter can be specified by means of a locking bushing which can be easily adjusted on a predetermined scale and is slidably mounted on the telescopic inner drill.

The support basket is balanced in conjunction with the two tubes forming the guide device and their bearing on the handle in such a way that a corresponding drilling machine can stand independently on the support basket without additional support, so that there is no lateral movement when drilling.

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holding forces are required and the flat support of the support body reliably prevents jamming or diagonal drilling.

Another advantage is that when the handle screw connection is tightened, the first, i.e. outer, bearing tube is held and secured completely immovably in its through hole in the handle, whereby an additional adjustment option is available at this point, since the first bearing tube in its handle position and the second inner bearing tube, due to its telescopic ability into the first bearing tube, provide two different axial adjustment options, so that a particularly broad, optimal range of applications is available.

The guide and drilling depth stop device according to the invention is easy to handle, easy to adjust and consists of only a few parts, whereby the support basket additionally enables the integral assignment of a suction arrangement, so that work can be carried out dust-free and shielded and a reliable determination of the drilling depth, drilling accuracy and drilling process is possible by the guide and drilling depth stop device, although the actual working area of the drill or chisel cannot be observed by the user because it is covered by the suction arrangement.

Finally, it is advantageous that the guide and drilling depth stop device according to the invention can be used to equip any drilling machine that has a corresponding drilling machine neck (Euronorm) onto which the handle with the telescopic tubes and the support basket fits, or which has another common size to which a corresponding handle can be adapted. It is also possible to receive and hold the outer bearing tube directly in a receiving hole in the drilling machine housing or in an additional ring.

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Finally, it is advantageous that it is not necessary to loosen the handle to set the desired drilling depth, since a removable locking bushing only needs to be set to the desired depth value on a corresponding millimeter scale on the second bearing tube, which can be inserted into the interior of the first bearing tube. The second tube can then only be inserted into the first bearing tube until this depth value is reached.

The measures listed in the subclaims make advantageous further developments and improvements of the guide and drilling depth stop device specified in the main claim possible. A particularly advantageous fact is that even when the inner tube is fully extended, it is guided on both sides in the first bearing tube, so that the two tubes that can be telescoped into one another are guided cleanly and the vertical alignment of the hand drill is guaranteed in every position.

!Drawing

An embodiment of the invention is shown in the drawing and is explained in more detail in the following description. They show:

Fig. 1 is a side view of a conventional hand drill equipped with the guide and drilling depth stop device according to the invention, supplemented by a dust extraction arrangement, and

Fig. 2 is a top view of the representation in Fig. 1 with the dust extraction arrangement removed and the device pushed through to the drilling base,

Fig. 3 is a vertical sectional view of an embodiment of the guide and drilling depth according to the invention.

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stop device with associated (additional) drill handle,

Fig. 4 a plan view of the support basket or foot of the guide device, detached from the second bearing tube attached to it and the

Fig. 5 and 6

a section through the support cage representation of the figure along the lines V and VI,

Fig. 7 shows the support basket with inserted dust extraction arrangement in a top view, with the locking bush and the second bearing tube carrying the support basket shown partially in section,

Fig. 8 shows the (additional) handle to be attached to the drill neck and carrying the two telescopic tubes with lower foot or support basket in section and the

Figs. 9 and 10

show the dust extraction arrangement in section and in plan view.

Description of the embodiments

The basic idea of the present invention is to create a device that is easy to attach to a hand drill and simultaneously fulfills guiding, i.e. alignment, and drilling depth stop tasks. The device consists of two spring-loaded tubes that can be telescoped into one another, with a first outer tube being clamped in a predetermined position in a through hole on the hand drill, preferably in a through hole of a handle that is to be attached additionally or is always present there, and an inner tube is continuously slidably mounted in this outer tube, which has a flat support basket on its free end facing the drilling base*. The drilling

The

2110/ot/mii 10.12.1987

The depth stop is then specified by a possibility of limiting the telescopic ability of the two tubes into each other, while the guiding tasks are fulfilled by both tubes in conjunction with the wide-surface support basket. Furthermore, a dust extraction arrangement can be attached to the support basket in any rotational position.

In Fig. 3, the bearing outer tube of the guide and drilling depth stop device 10 is designated with 11, the bearing inner tube with 12. The bearing inner tube 12 carries, attached to it, a foot that serves to support the whole on a surface to be drilled or a work surface, which is referred to below as the support basket 13.

The bearing outer tube 11 has an inner bore 14 which is narrowed on one side, namely at the top in the plane of the drawing, by an inwardly projecting ring flange 15. This forms a passage opening 16 for the bearing inner tube 12 which is slidably received in the bore 14, with means being provided which only allow the inner tube 12 to emerge from the outer tube 11 to such an extent that even in the maximum extended position, as shown in Fig. 3, an upper end region of the inner tube is still gripped by the passage hole 16 narrowed by the ring flange 15 and is guided flush.

The ring flange 15 simultaneously forms an inner ring shoulder 17, against which a preload spring 18 abuts, which is located together with the corresponding part of the inner tube in the bore 14 of the bearing outer tube.

The structure is completed by a lower locking mechanism, which is designated 19 and is shown enlarged in detail in Fig. 11.

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It can be seen that the other end of the preload spring 18 is supported on an inner spring plate 20, which is held at this height by a locking cross pin 21 on the inner bearing tube 12. A second washer 22 can be provided, with which the inner bearing tube 12 then rests on a closure cap 23 under the action of the preload spring 18, which in the simplest case could be formed by an inwardly directed flange of the bearing outer tube at this point; in the embodiment shown, the closure cap 23 consists of a plate-shaped part, preferably made of plastic, with an inner bore 23a, which flush-fits the inner tube 12, which is slidably mounted in this way, in a bushing-like manner, while the outer diameter of the closure cap 23 is dimensioned such that it can be pushed flush into the outer tube 12 at this point. Anchoring can be achieved by inserting grub screws on the side, but also as shown in detail in Fig. 11, namely by a raised outer ring wall 23b of the closure cap ending in at least some places distributed around the circumference in locking hooks 24, which engage in correspondingly aligned recesses in the inner wall of the bore 14 of the outer bearing tube and thus secure the closure cap immovably in its seat.

The cross-sectional shape of the bearing outer tube 11 is preferably square with slightly rounded edges, as shown by the receiving bore 25 of the handle 26 to be additionally attached to the drilling machine in Fig. 8.

Accordingly, in an advantageous embodiment, the cross-sectional shape of the bearing inner tube 12 is square or rectangular, in any case non-circular, in order to achieve a torsion resistance, so that when the

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Support basket 1 3 the hand drill cannot rotate around the support basket.

It can be seen that a relative movement of the bearing outer tube 11 to the inner tube, which rests stationary on the base with the support cage, along the direction of the double arrow A results in the bearing inner tube being pushed in and pushed through the outer tube until the preload spring 18 prohibits further pressing.

The possible insertion depth, which then simultaneously forms a drilling depth stop, can be limited by a locking bush 27 which is arranged on the inner bearing tube so that it can slide but can be locked, and which can itself be moved along the double arrow B on the inner tube which emerges from the bottom of the outer bearing tube and can be locked in any desired position by operating a locking screw 20b. The locking screw 20b sits in a thread of the locking bush 27 and presses against the inner bearing tube 12 with its inwardly projecting screw end 27c.

The lower end of the bearing inner tube 12 is held in a square receiving section 28 of the support cage 13, preferably in a non-detachable manner, for example in a press fit.

The support basket itself can be of any shape; in the embodiment shown, the support basket forms a flat plate of more than semicircular shape with an inner bore 13a that also encompasses more than a semicircle. To reduce the weight, the support basket can consist of rib-shaped, interconnected structures, as shown in Figs. 4, 5, 6 and 7, whereby the receiving opening 28 for the inner bearing tube 12 is in any case positioned so that the center of the drill bit, with the

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the hand drill equipped with the guide device according to the invention, lands exactly in the circle center 29 of the support basket, marked by a cross. This is ensured in any fastening position, for example of the handle 26 on the drill neck; the user therefore has a perfect sighting option, formed by the ribs 3Ö directed towards the centering center 29 on the two narrow sides of the horseshoe shape of the support basket and 31 on the curved base part.

These sighting options are further enhanced by internal projections 32 ending in a point, which also point to the centering center 29 and serve another purpose, which will be discussed shortly.

A further advantageous embodiment of the present invention is that a dust extraction arrangement can be attached to the support basket or base of the guide device, which is shown in Figs. 9 and 10 and is designated with . This dust extraction arrangement comprises a widened lower mouthpiece 34, which in this case follows a circular shape, and a nozzle-shaped, continuing connection 35, with a through-hole 36 being provided in the nozzle 35, which is required and which enables the drilling tool to pass through the dust extraction arrangement and make the desired hole in the base.

The circular lower mouthpiece 34 of the dust extraction arrangement 33 has on its outer edge notches 32 which are complementary to the pointed projections 32 of the support basket 13, but with a distance reduced by half, following the circular shape, so that the dust extraction arrangement can be inserted into the middle of the support basket 13 at an angle of 45° and then pushed in slightly to lock it in place.

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is rotated to a suitable angle. As a result of this rotation, the pointed projections 32, which initially fall into the notches 32', then grip over the lower projections 37, which protrude outwards and are arranged on both sides of the notches, as shown in Fig. 9, so that the dust extraction arrangement is firmly connected to the support basket 13 in the desired position. The hose leading on to a suction device, for example a vacuum cleaner or the like, can then be pushed onto the connecting piece 35.

It can be seen from the illustration in Fig. 8 that the (larger) bore 25* of the (additional) handle 26 for the drill, which receives the drill neck, is arranged opposite the receiving opening 25 for the guide and drilling depth stop device, whereby a gap is formed which is tapered or widened by turning an immediate hand rest 39 IEi in one direction or the other according to the double arrow C under the effect of a screw connection 40 known in this context, so that the fastening can be carried out in the desired position on the drill chuck neck and at the same time the bearing outer tube can be positioned and clamped accordingly in its through-bore 25 on the handle 26.

Fig. 1 shows the guide and drilling depth stop device 10 according to the invention in the assembled state and assigned to a hand drill 41, whereby it can be seen that in the lower support surface of the foot or support basket 13 there is also a groove or milling 42 enclosing an obtuse angle, so that this also provides a slip-proof placement option on round or curved drilling templates, such as pipes and the like.

All features presented in the description, the following claims and the drawing can be essential to the invention both individually and in any combination with one another.

Claims (1)

DIPL-ING. PETER OTTE fWBNTAN\Ä/AliT::..: D-7250Leonberg Representative at the European Patent Office / European Patent Attorney Tiroler Straße 2110/ot/mu
10.12.1987 Company Kress-elektrik GmbH & Co. Elektromotorenfabrik, Hechinger Straße, 7457 Bisingen fcprotection claims 1. Guide and drilling depth stop device for hand drills, with a rod-shaped element mounted in a guide on the drill and arbitrarily lockable, characterized in that a first bearing outer tube (11) in a passage opening (25) is securely clamped to the hand drill, that a second bearing inner tube (12) is slidably received against spring pressure in a bore (14) of the first bearing outer tube (11) and that a support basket (13) resting flat on the drilling base is attached to the free end of the second bearing inner tube (12). 2. Guide and drilling depth stop device according to claim 1, characterized in that in the inner bore (14) of the first bearing outer tube (11) both the rear part of the bearing inner tube (12) and, surrounding it, a preload coil spring (18) are arranged, which presses the bearing inner tube (12) into its position in which it is maximally extended from the bearing outer tube (11). 3. Guide and drilling depth stop device according to claim 1 or 2, characterized in that the bearing inner I·· I I · 2110/ot/mu " " ' 10.12.1987 - 2 - The support basket (13) which is permanently attached to the tube (12) has a large, generally horseshoe-shaped configuration with wings extending beyond a semicircle on both sides, and a dust extraction arrangement (33) can be attached to the inner bore (13a) of the support basket (13). 4. Guide and drilling depth stop device according to one of claims 1 to 3, characterized in that a locking bushing (27) with a locking screw (27b) is arranged so as to be slidable and lockable along the part of the bearing inner tube (12) protruding from the bearing outer tube. 5. Guide and drilling depth stop device according to one of claims 1 to 4, characterized in that the length of the inner tube (12) is dimensioned such that it is guided at both ends of the bearing outer tube (11) even with maximum telescopic exit from the bearing outer tube. f. Guide and drilling depth stop device according to claim 5, characterized in that the bearing outer tube (11) has on one side an inwardly projecting end flange (15) which itself forms a through-sliding opening (16) for the inner tube (12) and, with an inner annular shoulder (17), forms the stop for the pre-tension spring (18). 7. Guide and drilling depth stop device according to one of claims 1 to 6, characterized in that the exit path of the inner tube (12) from the outer tube (11) caused by the spring preload is limited by a transverse stop. 8. Guide and drilling depth stop device according to claim /3 2110/ot/mii 10.12.1987 - 3 - 7, characterized in that the transverse stop is formed by a pin (21) passing through the inner tube (12), which supports a spring plate (21) forming the second stop for the pre-tensioning spring (18) on the inside and rests on the outside, optionally via a washer (22), against a locking mechanism (19) inserted into the outer tube (11). 9. Guide and drilling depth stop device according to claim 7 or 8, characterized in that the locking mechanism (19) comprises a locking cap (23) which engages with locking projections 24 in inner locking recesses of the bearing outer tube (11). 10. Guide and drilling depth stop device according to one of claims 1 to 9, characterized in that the (additional) handle (25) forming the non-circular through-opening (25) for receiving the bearing outer tube (11) has, opposite this through-opening, the through-opening (25') receiving the drilling nut neck, both of which can be changed in their diameter in a manner known per se by turning the immediate hand rest (29) via a screw mechanism in order to clamp the outer tube and the drilling nut neck. 11. Guide and drilling depth stop device according to one of claims 1 to 10, characterized in that the support basket (13) consists of ribs connected to one another in the manner of a grid and has an inner annular rib extending beyond a semicircle, which forms the receiving shape for a dust extraction arrangement (33) that can be used in any of the different angular positions, the grid ribs also forming a sighting arrangement for the center of the bore. /4 2110/ot/mu ...... 10.12.1987 - 4 - 12. Guide and drilling depth stop device according to claim 11, characterized in that the dust extraction arrangement (33) consists of a circular mouthpiece (33) and a continuing nozzle (35) and that the mouthpiece has notches (32') over its circumference into which, when inserted into the partially open central annular recess of the support basket (13), locking tips (32) which are one piece with the support basket engage, which engage over projections (37) on the dust extraction arrangement (33) for locking during subsequent twisting for fixing. 13. Guide and drilling depth stop device according to one or more of claims 1 to 12, characterized in that a scale (43) arranged on the inner bearing tube (12) is positioned directly at the level of the outlet opening from the outer bearing tube (11) when in the maximum extended position.