MULTIPLE SPINDLE DRILLING HEAD

Abstract: Multiple drilling head with a central drive appliance (17) in an enclosing cage (33) and comprising tool holders (6, 28) placed concentrically around the head and separately driven on a disconnectable tooth belt transmission.

Description: MULTIPLE DRILLING HEAD The invention relates to a multiple drilling head for working wooden workpieoes with a central drive appliance in an enclosing cage and at least two driven tools each of them clamped in an individual chuck. For maching wooden workpieoes, for example furniture parts, a great number of operations are sequentially carried out. Existing equipments in the metal working sector are less suitable because they are either too circumstantial for certain operations, or not sufficiently economical. Particularly the drilling of longitudinal holes, i.e. narrow longitudinal slots, is an operation which in the furniture sector must take place very rapidly and with great accuracy. The described drilling head relates to an apparatus containing different toolholders with axes of rotation parallel to the central drive appliance. The tools are in the standard version drills or fingercutters, but may consist also of other existing cutting tools. The drilling head has a simple design and preferably contains a belt transmission. It is easily adJustable and can make several holes according a predetermined pattern, even within very small distances. The drilling head is very suitable to be used on a monitoring unit as described in the Belgian patent 875.770. The drilling head according to the invention contains several tool holders which are mounted by means of a connecting part on the enclosing cage so that the tool holders are concentrically placed around the cen trawl drive appliance. According to the invention, the individual toolholders have separate, disconnectable driving means and preferably a teeth-belt transmission. According to the invention, the individual tool holders also are mounted on separate circle segments of the enclosing cage at a mutual distance of between 1 and 20 times their mean diameter. Preferably the tool holdersaittuated at the periphery of the same circle. As diameter of the tool holder is considered the largest radial dimension of the combination of holder and tool. The following description is a clarification of an embodiment of the multiple drilling head which is particularly suitable for making the end connections of wooden furniture parts. A cyclic reciprocating movement of the multiple drilling head for example when using end cutters 28 very useful to obtain a number of longitudinal slots or dowel holes which are an advantageous and strong connection in furniture assembly. Figure 1 is a front view of a multiple drilling head. Figure 2 is a cross-sectional view of the drilling head of Figure 1 according to the vertical plan I I. To clarify the principle no more than two tool holders are shown in driven condition, which corresponds with the standard embodiment. However, it is possible to extend the principle to more concentrically mounted tool holders. The cover plate 1 forms the front side of the enclosing cage 33 which encases the transmission belt discs. The cylinders 2 guide the drilling head with its driving means in its movemn t towards and away from the workpiece. A T-shaped slot 3 is concentrically made in the cover plate 1. An enlargement 4 at the front allows to introduce fitting segmental clamping blocks 5 into the slot and to remove them out of it. The cylindrical chuck 6 which at the front side is provided with a belt disc 7 in which the toothed belt 8 meshes, is bearing-supported in the connecting piece 9 which consist of the bearing bush 10 and the supporting arm 11. The supporting arm 11 is fixedly clamped by means of a screw 12 to the clamping block 5 in the T-shaped slot. The toothed belt 8 is in mesh with a fitting motordriven belt disc 13. The cover plate 1 is fixed by an underplate 14 and a clip 15 to the rear side 16. These components together form the enclosing cage of the central drive. These details are also shown in Figure 2. The central shaft 17 is directly driven by the motor or via a speed reducing device. The rotation is transmitted by the key 18 to the catch ring 20 via the bearing flange 19. On the circumference of the catch ring there are a couple of transverse slots 21 in which a wide-headed screw 22 can be slid without play so that, if so desired, the catch pin 23 can be slid laterally in an aperture 24 of the belt disc 13 and the belt disc is fixedly clamped to the driving shaft 17. A ring 25 made of elastomer material will damp possible vibrations. In a similar manner the second belt disc 26 can be connected to a second catch system 27 to drive a second chuck 28 which is mounted on a long supporting arm 29. For simplicity only two belt discs are described here. It is evident that it is possible to mount a greater series of tool holders and a corresponding number of belt discs. In addition, a chuck 30 may also be mounted on the cover plate 31 of the central drive (shown in Figure 1). The supporting arm 29 in Figure 1 has a greater length than supporting arm 11. In this manner holes can be drilled at an arbitrary distance from each other. If so desired, a supporting arm 32 with equal length can be used instead. Although the clip 15 is a very useful reinforcement of the enclosing cage, it can be omitted by using a stronger type of cover plate 1 and underplate 14 so that supporting arms can be mounted and adjusted to all positions.

Claims: Claims 1. Multiple drilling head for machining wooden workpieoes with a central drive in an enclosing cage and at least two driven tools which are each seized in an individual tool holder, characterized therein that the individual tool holders (6, 28) are mounted on the enclosing cage (33) by means of a connecting piece (11, 29, 32) so that the individual tool holders are placed concentrically movable around the central drive appliance (17). 2. A multiple drilling head according to claim 1, characterized in that each of the individual tool holders (6, 28) is separately driven on a disconnectable teeth-belt transmission. 3. A multiple drilling head according to one of the claims 1 or 2, characterized in that the individual tool holders are mounted on separate circle segments of the enclosing cage (33), at a mutual distance of between 1 and 20 times their mean diameter. 4. A multiple drilling head according to one of the claims 1, 2 or 3, characterized in that two or more tool holders (6, 28) are situated on the periphery of the same circle.

Inventors: DE MUYNCK, GABRIEL
Applicants: BEKAERT ENGINEERING
Application year: 1980
Main classification: B23B39
IPC codes: B23B39