DE9212442U1 - Countersink - Google Patents

Description

Jörg H. Wilms
Westhauser Str. 52
Remscheid
02191/71585

Countersink Page 5 JW

Description

Countersink for ring dowels

Technical area

Countersink for ring dowels (e.g. APPEL, GEKA or similar) e.g. in structural timber construction.

State of the art

Ring dowels are increasingly prescribed and used in structural timber construction as a secure but detachable connection.
However, installation is often quite difficult in practice, as at best there are countersink systems with independently adjustable cutting edges. With these countersinks, setting the cutting edges to a common flight circle is very

time-consuming and often only possible with errors, so that the
The desired result - the ring groove - is not achieved.
Single-sided ring dowels can only be pre-drilled with a countersink (drill with a guide pin) and are therefore not able to absorb the forces acting on them from all sides , as they can then only bear the load on the outer diameter.

Jörg H. Wilms
Westhauser Str. 52
Remscheid
02191/71585

Countersink Page 6 JW

problem

The invention specified in claims 1-5 is based on the problem of creating a countersink that can be used as a universal tool in soft/hard wood and glued wood, and in drilling machines with and without a drill chuck (claim 3). This tool should also be used for the various ring dowels (such as APPEL, GEKA and similar), as well as economically and accurately producing ring grooves for dowels of the same system, but in different diameters (e.g. APPEL = 65, 80 and 95 mm). Furthermore, dowel seats for one-sided ring dowels should be worked into the wood with a precise fit.

Jörg H. Wilms
Westhauser Str. 52
Remscheid
02191/71585

Countersink Page 7 JW 2

Advantageous effect of the invention

The invention makes it possible - by changing the cutting edge holder - to quickly adapt to any desired ring dowel diameter in daily practice. Different dowel systems (APPEL, GEKA etc.) require different ring groove shapes, which can be achieved by simply changing the cutting edges. HSS cutting edges enable use in soft and hard wood as well as glued laminated timber. The interchangeable shank (MK holder or three-face clamping shank) makes the tool suitable for any drilling machine. The depth adjuster limits the inlet depth and ensures that the ring groove is flat. At the same time, the depth adjuster acts as a "safety cage".

Description of the invention

An example of the one-sided and two-sided ring dowel is shown as a sketch as follows:

Fig.l Two-sided ring dowel
Fig.2 One-sided ring dowel
The countersink itself is shown in cross-section in Fig.3.

Jörg H. Wilms
Westhauser Str. 52
5630 Remscheid
02191/71585

Countersink Page 8 JW

Manufacturing of the invention

To ensure that the finished tool is sufficiently strong and tough, the drive shaft, cutting edge holder and replaceable guide pins are made of CHROME-VANADIUM. The cutting edges themselves are made of HSS material. The depth gauge is made of aluminum.

Summary

The invention was designed to create a new countersink for ring grooves, in particular for ring dowels with different shapes (e.g. APPEL, GEKA). The countersink can be easily adapted to the respective dowel diameter using interchangeable cutting edge holders. By exchanging the cutting edges themselves, ring grooves can be produced for different dowel systems (APPEL, GEKA etc.). The depth adjuster attached to the tool takes over the depth limitation, the plan guidance and the function of a "safety cage".

Thanks to its interchangeable shank, the countersink can be used alternatively in drilling machines with both an MK shank and a three-face clamping shank.

Jörg H. Wilms
Westhauser Str. 52
5630 Remscheid
02191/71585

Countersink Page 1 JW 2

Task

In structural timber construction, ring dowels are increasingly being used as a detachable but secure connection (e.g. APPEL system, GEKA). The advantages of the high shear, tensile and shear force absorption are beyond doubt - only the processing is not entirely straightforward in practice, as ring grooves have to be drilled.

Users of conventional carpentry drills usually use tools with Morse taper shafts, while the new high-torque craftsman drills usually have a 13 mm chuck. It is therefore necessary to develop a tool that can be used with both MK shafts and cylindrical shafts. This tool should also be usable for the various dowel shapes (depending on the manufacturer).

Jörg H. Wilms
Westhauser Str. 52
5630 Remscheid
02191/71585

Countersink Page 2 JW

Solution

The newly developed countersink can

1) can be adjusted to any ring dowel (e.g. APPEL 65, 80 or 90 mm) by changing the cutting holder .

With cross cutting also for one-sided ring dowels.

2) can be adjusted to different groove shapes (e.g. APPEL, GEKA or similar) by changing the cutting edges .

3) can be adapted to the existing machine (drill chuck or MK holder) by changing the mounting shaft (three-face clamping shaft or MK shaft).

The attached depth divider (ball bearing) ensures:

1) always the correct ring groove depth and

2) next to the guide pin (in axial direction) the flat inlet of the annular groove, since the depth adjuster rests flat on the workpiece during the drilling process.

3) Work safety, as it rests on the workpiece before drilling begins, remains stationary during drilling and thus acts as a "safety cage" for the cutting edges rotating inside.

Claims (5)

Jörg H. Wilms Westhauser Str. 52 Remscheid 02191/71585 Countersink Page 3 JW Claims Countersink for ring grooves (e.g. for APPEL, GEKA etc.) particularly characterized by the fact that 1) For each dowel diameter (e.g. 65, 80, 95 mm) a corresponding cutting holder is placed on the drive shaft. 2) the cutting edges are interchangeable in different shapes for the corresponding dowel system (APPEL, GEKA etc.) on the cutting edge holder. 3) the drive shaft is split and can therefore be combined with a three-face clamping shaft for a three-jaw drill chuck or alternatively with an MK clamping shaft. 4) an outer basket is placed over the countersink drive shaft from behind and is forced behind the countersink head by a pressure spring and counter ring . As the outer basket is ball-bearing mounted, it can rotate freely relative to the countersink shaft or remain firmly on the wood surface when the countersink is working. The outer basket therefore acts as a guide aid, safety basket and depth adjuster. Jörg H. Wilms Westhauser Str. 52 5630 Remscheid 02191/71585 Countersink Page 4 JW 2 Claims Countersinks for ring grooves (e.g. for APPEL, GEKA etc.) particularly characterized in that 5) the guide pins are interchangeable and can be accommodated in the drive shaft and thus adapted to any desired core bore.