HEADPIECE FOR MACHINE TOOLS THAT PRODUCE MULTIPLE HOLES

Abstract: A headpiece (1) is described for machine tools that create series of perforations by removal of shavings on flat boards, whereby said headpiece is equipped with a pneumatic system (10) for continuously sucking up and removing the shavings that are formed during machining. To said headpiece (1) are attached one or more shaft-like elements (2, 3), which push on board (4) that is to be drilled via one of their elastically yielding edges (2d, 3d), thus leaving exposed and encompassed between them an area (4t) of said board (4) where said holes (6n) are to be made, whereby a box (5), which is open toward above-mentioned area (4t) where holes (6n) are to be made and to which an aspiration system (10) is to be fitted, is attached, over its entire length, to at least one (3) of said shaft-like elements (2, 3).

Description: Headpiece for Machine Tools That Produce Multiple Holes. This invention pertains to the field of machine tools and, more specifically, to the part of that field that deals with machines that make multiple perforations at high speed, creating multiple holes on flat boards such as, for example, those that act as mechanical supports and insulators for conductors on printed circuit boards. These machines must necessarily be equipped with one or more headpieces, i.e., one or more devices that keep the board to be drilled stationary by causing it to adhere, in a perfectly flat manner, to a support and reference table. The invention pertains to a headpiece of the above-described type, but with innovative characteristics that make it possible to achieve the extremely advantageous effect of appropriately increasing the machine's efficiency, which depends to a substantial extent on the number of perforations that can be produced in a reference unit of time. Today's headpieces, which are equipped with a pneumatic system for sucking up the shavings that are produced during machining, move continuously, pressing from time to time on the area of the board to be machined where a hole is to be made. The total amount of time that it takes to make a single hole therefore consists of the time that it takes the headpiece to reach the board starting from an initial standby position and the time it takes the headpiece to retract. The time required for the drilling per se therefore lies within this interval and is shorter than the latter, since the tip rests on the board to be drilled only after the headpiece has finished being compressed against an elastic packing with which it is equipped; this packing has to be used in order to avoid damaging the board itself and to ensure that uniform pressure is exerted on said board over the entire contact surface. The two lengths of time, elastic compression and elastic reexpansion of said packing, are therefore dead times that are added to the time that the drilling work itself takes. In the more common case mentioned above, where machining is done on printed circuit boards, the work of drilling, which involves advancing a few millimeters in a fairly friable material, lasts an extremely short time for each individual hole, and therefore the dead times involving the actual actuation of the headpiece increase substantially in terms of percentage. The inventor of this invention has developed the idea of a headpiece which, although it performs the actual functions that need to be performed and that were described above, does not involve any dead time that is added to that of the actual work of sucking up shavings. As a matter of fact, a headpiece that is produced according to the invention actually adheres to the entire area of the board where the holes are to be made and therefore does not need to be moved in a cyclic fashion per se to help with drilling that is done in succession in space and time. The object of the invention is, in fact, a headpiece as described in the preamble to attached claim 1, which is characterized as described in the characterizing part of the above-mentioned claim. A preferred embodiment of a headpiece according to the invention will now be described, whereby, however, this example is neither limiting nor binding with respect to the other embodiments that can be produced by implementing the teachings contained in above-cited claim 1. In the description given below, reference will also be made to the attached drawings, where: - Figure 1 shows a partially cut-away frontal view of the embodiment of a headpiece according to the invention; - Figure 2 shows a partial view of an enlarged cross-section of said headpiece. Figure 1 shows how, to a headpiece 1 according to the invention, one or more shaft-like elements 2, 3 (two in the example in question) , which push on board 4 that is to be drilled via its elastically yielding edge 2d, 3d (which bends, in this case) , are attached, thereby exposing area 4t of said board 4 where multiple aligned holes 6n are to be made. In the case in question, said two shaft-like elements 2, 3 are arranged horizontally and parallel to one another so as to leave a linear area 4t of board 4 exposed and accessible to drilling tips 11 (see Figure 2) . All of perforations 6n that are to be made in said area 4t can be made without having later to move headpiece 1, which has to be disengaged only after the machining of board 4 has been completed. As regards the aspiration that is required to remove the shavings, to a headpiece 1 according to the invention an aspiration system 10 can is attached, in such a way as to create in it an appropriate underpressure at two boxes 5, which have one or more holes 7n facing area 4t that is located between shaft-like elements 2, 3 where the shavings are created during the machining of the holes. The shavings, assisted by the force of gravity acting on them, are mainly sucked up into lower box 5 and are then removed toward a collection area (not shown in the drawing, since it is such a common item) . The other shavings, which are driven upward by centrifugal or other forces, are aspirated into other box 5, located above. In order to ensure more efficient operation of the shaving removal system, it is preferable to create, at the edge of each box 5 that faces toward corresponding shaft-like elements 2 , 3 , several holes 7n, which are arranged appropriate distances apart and to which lead an equal number of compartments 5i of said boxes 5 that are attached to aspiration system 10. In order to achieve an aspiration effect that is uniform and balanced over the entire length of area 4t where the perforations are made, it is necessary to shape and size compartments 5i such that in each of them there are identical overall losses of load to the air that flows through them carrying the shavings. One possible solution was created with compartments 5i made as indicated in cutaway view in Figure 1. With regard to edges 2d, 3d of above-mentioned shaft-like elements 2, 3 which yield elastically to bending, the inventor proposes that they be made in the form of flexible brushes 2d, 3d that are tilted as shown in Figure 2, i.e., in such a way as to direct the shavings that are formed toward above-mentioned holes 7n in boxes 5 that are attached to aspiration system 10. It turns out to be especially advantageous to use brushes made up of bristles as shown to produce elastically yielding edges 2d, 3d when it comes to cleaning shaft-like elements 2 , 3 of the machine tool on which a headpiece according to the invention is used, since the shavings are unable to adhere to the machine tool to later filter into its structure, and in special cases, even if this should happen, it is very easy to remove them mechanically.

Claims: Claims : 1. Headpiece (1) for machine tools that produce a series of holes by removal of shavings on flat boards, whereby said headpiece is equipped with a pneumatic system (10) for continuously sucking up and removing the shavings that are formed during machining, characterized by the fact that to said headpiece are attached one or more shaft-like elements (2, 3) which push on board (4) that is to be drilled via an elastically yielding edge (2d, 3d) , leaving exposed and encompassed between them an area (4t) of said board (4) where said holes (6n) are to be made, whereby to at least one (3) of said shaft-like elements (2, 3) is attached, over its entire length, a box (5) that is open toward said area (4t) where holes (6n) are to be made and is attached to an aspiration system (10) , which creates in said box an underpressure that is able to aspirate the above-mentioned shavings. 2. Headpiece according to claim 1, in which box or boxes (5) that is (are) attached to aspiration system (10) is (are) open toward said area (4t) where perforations (6n) are to be made by means of a series of openings (7n) that lead to an equal number of compartments (5i) in boxes (5) , which are in turn independently connected to the aspiration system itself. 3. Headpiece according to claim 2 , in which each of said compartments (5i) is of such a shape and size that, as the aspirated air that carries the shavings passes through them, the total losses of load for each compartment (5i) are identical. 4. Headpiece according to one of the preceding claims, in which there are two of said shaft-like elements (2, 3), which are arranged horizontally and parallel to one another, and to each of which is attached one of said boxes (5) . 5. Headpiece according to one of the preceding claims, in which the elastically yielding edge of each of above-mentioned shaft-like elements (2, 3) is made with natural or man-made bristles that form a flexible brush (2d, 3d) , whereby the bristles themselves are pressed obliquely against plate (4) in which holes are to be made. 6. Headpiece according to claim 5 in which flexible brushes (2d, 3d) are tilted in such a way as to direct the shavings that are formed toward holes (7n) in respective boxes (5) that are attached to said aspiration system (10) .

Inventors: AMMANN BEAT, AMMANN, BEAT
Applicants: AMMANN BEAT, BALLADO INVEST INC, AMMANN, BEAT, BALLADO INVESTMENTS INC.
Application year: 2000
Main classification: B23Q11
IPC codes: B23Q3, B23Q11, H05K3