This invention relates to milling cutter chip breakers .

The chip breaker breaks up chips removed from the workpiece by the cutting tool and usually comprises a hood which prevents chips scattering and channels them to an extractor system. On one side of the cutting tool is the chip breaker shoe while on the other side, is a workpiece pressure pad which holds the workplaces against the bedplate. It is desirable that these elements operate close to the cutting tool.

Because the milling cutter must use different cutting tools to cut different profiles on different workpieces , it is required to provide adjustment for the pressure pad and for the chip breaker shoe.

This is conventionally done by arranging the pad and shoe on brackets with provision for manual adjustment via guide slots and clamping screws both parallel to and perpendicularly to the bedplate. Adjustment is carr e out by effecting each independent adjustment i turn and several times until the right combination cf perpendic¬ ular and Darallel movements is hit uoo . The crocess is

time consuming and only as accurate as the skill cf the operator allows, and can lead to scrap components.

The present invention provides a milling cutter chip breaker without this disadvantage.

The invention comprises a milling cutter chip creaker comprising a support mounting an operative chip breaker element adjustably and with tangential movement relatively to a cutting tool.

Said element may be resiliently urged towards a workpiece.

Said element may comprise a chip breaker shce, which may be pivotaliy mounted en the support - e pivot may be on the side of the cutter tool remote from the sho .

The said element may, however, comprise workpiece pressure pad on the rear side of the cutter tccl remote from the chip breaker shoe. The pad may be ".cuntec in a slide.

The support may be adjustable perpendicularly :e miiiin cutter bedυlate.

The support may comprise two support me oers relatively adjustable lengthwise cf the bedplate, cne support member supporting the chip breaker shoe and the other support member supporting a workpiece pressure pac , whereby the shoe and the pad are relatwely adjustable lengthwise cf the bedplate.

The support adjustment may be effected auto¬ matically, for example by electric motor means under computer control. The arrangement may comprise a cutter tcci measuring device inputting tool measurements to the computer which is programmed to determine chip breaker adjustments tnerefrcm and to command the motor means to effect same.

One embodiment cf a milling cutter chip breaker according to the invention will now be described with reference to the accompanying drawings, in which :-

Figure 1 is a sectional side elevation;

and Figure 2 is a plan view cf tne chit, breaker cf

Fiαure 1.

Figures 1 and 2 illustrate a milling cutter cr.t: breaker 11 comprising a support 12 mounting a operative

chit breaker element 12 adjustably and with tangential movement relatively to a cutter tool 14.

The element 13 comprises the chip breaker shce. It is tivotaiiy mounted on the support 12. the pivot 1: be__.nc en tne side cf the cutter tocl 14 remote i cir. tne shce 13, the shoe 12 being on a bracket 13a ana cemg resiiientiy urged towards a workpiece 16 indicates, i oroken line) en the bed plate 17 of the milling cutter by a cylinder 13 pivoted at 19 on the support 12.

It will be seen that the edge 13b of the chip breaker shoe 13 has tangential movement relatively to the cutter tool 14 along the arc 21 centred on the pivot 15. It is not, of course, important that the movement be .exactly tangential to the cutter tool, but that tne edge 13b is always closely - but safely - spaced from the tool 14.

A workpiece pressure pad 22 is located on the rear side of the cutter tool 14 remote from the chit breaker shoe 13 and is also an operative chip breaker element mounted en the suotort 12 ad ustabiv and witr. angular movement f45° ) relatively to the cutter tccl 14. The pad 22 is mounted on a slide 22 which i= inclined at 45° to the bedplate 17 and which is

resiliently held therein with a pneumatic pressure arrangement 24.

The support 12 - which includes a hood 12a with an upper outlet 12b connectible to an extraction system not shown - is adjustable perpendicularly to the bedplate 17 on a slide 25 by an electric motor 26 driving a lead screw 26a on which a nut runs attached to the support 12. .

The support 12 comprises two support members 12 and 12R relatively adjustable lengthwise of the bedplate 17. Support member 12R supports the chip breaker shoe 13, by carrying the pivot 15 thereof. The other member 12 supports the pressure pad 22 by supporting the slide

Each member 12R,I2L has a nut engaging a lead screw 27 which has opposite hands of thread on the two parts that engage the nuts. The lead screw 27 is turned by an electric motor 28 working through a worm gear 2? and timing belt and pulley arrangement 31.

Shaft encoders 32 comprise input to a computer net shown which operates the motors 26,23. The computer is supplied with information about the workpiece thickness and the tool dimensions - in either case bv

- D -

measuring devices not shown or via a keyboard input - tc determine the adjustment of the support 12 perpendicular to the bedplate 17 and the relative adjustment of the support members 12L and 12R.

Thus a complex, time consuming and imprecise adjustment which can only be carried out manually ey a skilled operative is reduced by the invention tc a simple and ^" straightforward adjustment which can be carried out manually or by manual data input or automatically under computer control.