CH635257A5 - MACHINE FOR GROOVING PLATES. - Google Patents

Description

The invention relates to machines for grooving plates on their two faces, and in particular plates for printed circuits.

Considering more specifically, in what follows, said plates for printed circuits, there is already known a method according to which the same plate is intended to support several printed circuits respectively on as many shelves as are formed in this plate, and that the it is separated, during use, by fracture along grooves made in generally orthogonal directions, preferably on each of the faces. To fix the ideas, we have shown in fig. 3 a plate P of this kind, with two sets of grooves Q facing each other on either side of the plate.

To prepare such plates, use is generally made of a milling machine of a conventional type, comprising one or more coaxial cutters. The circuit-carrying plate is then placed on a table suitable for being moved under the milling cutter train, then brought back. We must then turn the plate over and repeat the operation on the other side. This process is slow and therefore expensive. In addition, it is necessary to constantly touch up the adjustment of the guide stops of the plates, to be sure that the second series of grooves is indeed opposite the first.

It has already been proposed also to obtain the two sets of grooves by single passages, and for this purpose passing the plates to be grooved, carried by an appropriate frame, between two sets of fixed punches facing two by two. This formula has the drawback of rapid wear of the punches, leading to adjustment difficulties, and that of slowness, given the need to move the frame back to its starting position after each pass.

To overcome these various drawbacks, it is proposed, in accordance with the invention, a machine comprising two lines of tools capable of respectively digging the two faces and means for passing the plates between these tools, characterized in that said tools consist of two sets of rotary cutters facing parallel axes.

The plates are driven advantageously from a magazine at the base of which each plate is driven by carriages carried by chains, the whole being preferably installed in a variable width system, so as to be able to adapt to plates of different dimensions. For this purpose, for example, the chains are carried respectively by two guides, one fixed, the other located at an adjustable distance from the first.

Other adjustment means are provided, in particular to allow the two sets of cutters to be moved aside at will, according to the desired depth for the grooves.

The invention may, in any case, be well understood with the aid of the additional description which follows, as well as of the appended drawings, which supplement and drawings are, of course, given above all for information:

fig. 1 shows in perspective, parts cut away, a machine for grooving printed circuit boards, established according to the invention;

fig. 2 shows separately and schematically, in perspective, the milling system that this machine comprises;

fig. 3 shows, by way of indication, a printed circuit board, to be grooved;

fig. 4 illustrates separately, in section and on a larger scale, characteristics of the grooving;

fig. 5, finally, shows separately and on a larger scale, in perspective and torn portions, a driving carriage that comprises said machine.

For a double grooving of printed circuit boards, intended to allow easy separation of the shelves thus formed, it is ensured that the plates P are brought, while being suitably driven and guided, to pass in the interval separating two trains of cutters themselves established at suitable distances, depending on the spacing of the grooves Q to be provided.

To this end, the machine, shown in FIG. 1, essentially comprises on a frame A:

Two guides B and C established parallel to adjustable distances, one B being for example fixed, while the other C is adjustable, in particular by an N screw system or any other device,

- C conveyor chains! and C2, mounted along said guides and suitable for driving, by carriages as shown diagrammatically at M, the plates P to be grooved,

- an adjustable magazine L of plates P, magazine disposed above the path of the chains, so that, by suitable driving means such as fingers carried by carriages M and cooperating with the orifices of the plates, said carriages ensure the transfer , from plate P located at the base, towards the milling cutter trains,

- two sets of milling cutters It and I2 mounted on superimposed shafts I, carried by frames E, F and likely to be brought to dis5

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tances adjustable h, by an adjustment system not shown in detail and operable for example in R, said shafts being preferably controlled from individual motors H and the frames E, F, or at least one of them in G, can themselves, if necessary,

be adjusted so as to present a freely adjustable distance between them,

- An intermediate table S, suitable for receiving the plate P to groove leaving the store L, and for maintaining it there to ensure the formation of the grooves Q, said plate being able to receive, during at least part of its course, the weight d '' a pressure cylinder K, io

- Finally, a receiving member J at the outlet of the assembly, to receive the plate which has just been treated.

It should be noted, regarding the intermediate table S, that it must be crossed by the cutters It from one of the two trains, I2. As an adjustment of the spacing of the cutters is provided as a function of the distance to be provided between the grooves, this table is made up of several elements, as shown in FIG. 2, these elements being carried by rods T on which they are held, after adjustment, by screws Uj or by any other means.

As an indication, there is shown schematically in FIG. 5, 20 a device for driving each plate P, at the base of the magazine L, by a finger U of the carriage M. This finger U, carried by a support base V and mounted to slide in said carriage, is retracted, at the time of its passage at the entrance of the store, by a ramp X. Said base V slides initially along a rail Y, by the support of a roller Z. The finger U therefore retracts at the time where the rail ends at the first ramp X, then it goes back up to the arrival on the second ramp X and thus engages in a corresponding orifice formed in the plate P to be driven.

To facilitate operations, it is advantageous to provide a temporary slowdown of the carriage, which can be obtained for example by a magnetic brake acting at a distance on the drive motor of the chains Cu C2.

Finally, the entire machine will be controlled from an appropriate control panel, visible at D.

Following this, a machine can be established, the operation of which already emerges from the above and can be summarized as follows.

The machine having been previously adjusted to meet the spacing and depth of the grooves, thanks to the various adjustment means that it comprises, a number of P plates are stacked in the magazine and the motors are started. H and the chains Q, C2. This causes the drive one by one of the plates out of the store, then the formation of grooves in the same direction simultaneously on both sides. The plates thus treated are ejected at J and they can then be reintroduced, after adjustment and after a 90 ° rotation, into the magazine, to ensure grooving in the direction orthogonal to the previous one.

The operating speed is therefore considerable and, at the same time, maximum security is achieved with regard to the coincidence of the grooves on the two faces.

The invention therefore has many advantages over machines of the kind in question already existing, in particular:

- possibility of working continuously and at high speed, especially given the fact that the cutters wear and heat relatively little, the cutting force of a cutter being distributed over a relatively large length of cutting edge if we compare it to that of a fixed punch,

- precision and clarity of work,

Flexibility of the adjustments, making it possible in particular to form grooves of different spacings and / or of different depths in plates of different thicknesses, and

- possibility of establishing grooves on one side of the plates, if desired, since the two motors H are independent and, moreover, it is possible, by adjusting the positions of the shafts I, to ensure that one of the trains of strawberries be put out of action.

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2 sheets of drawings

Claims (11)

635,257 1. Machine for grooving plates on their two faces in order to make possible their subsequent breaking along these grooves, comprising two lines of tools capable of respectively digging these two faces, and means for passing the plates between these tools, characterized in that said tools consist of two sets of facing rotary cutters (I ,, I2) with parallel axes. 2. Machine according to claim 1, characterized in that it comprises, in addition to the two sets of cutters, a magazine (L) of plates (P) and a chain conveyor system (C1 (C2) suitable for successively driving the plates leaving the store, to pass them between the two sets of strawberries. 2 3. Machine according to claim 2, characterized in that the distance between the driving chains, as well as the corresponding dimension of the magazine, are adjustable. 4. Machine according to claim 3, characterized in that it comprises two guides (B, C) one of which is fixed and the other adjustable in position, these guides respectively carrying the two chains and the corresponding walls of the magazine . 5. Machine according to one of claims 2 to 4, characterized in that the driving of the plates by the chains takes place using carriages (M) carried by said chains and provided with latching means specific to cooperate with corresponding elements of the plates to drive them to an ejection station. 6. Machine according to claim 5, characterized in that the latching means consist of fingers (U) capable of cooperating with holes made in the plates. 7. Machine according to claim 6, characterized in that the fingers are slidably mounted in the carriages, so as to be retracted at the entrance to the store, then to protrude again to penetrate the holes in the plates. 8. Machine according to one of claims 5 to 7, characterized in that means are provided for slowing down the movement of the carriages when they come to engage on the plate to be driven. 9. Machine according to one of claims 2 to 8, characterized in that the plate (P) leaving the store is received on a table (S) crossed by the cutters of one of the two sets of cutters, said table preferably being established in several removable and adjustable elements. 10. Machine according to one of the preceding claims, characterized in that the two sets of cutters are carried by supports (E, F) capable of being adjusted in position relative to each other. 11. Machine according to claim 10, characterized in that the two sets of cutters are mounted in an adjustable manner on their supports, in order to allow the distance between them to be adjusted, as a function of the thickness of the plates and / or the depth of the grooves.