In machining, use is made of vices between whose jaws the workpieces are clamped. In precision boring and / 5 milling, for instance, the workpiece has to be supported by an underlying structure defining an e.g. horizontal reference plane. Workpieces of different height (in the vertical direction of the jaws) require supporting ele¬ ments of different height, so-called parallels, which of

10 course are narrower (between the jaws) than is the work¬ piece.

Thus, it is necessary to replace the parallels when machining workpieces of different height, which naturally is an inconvenience. Before a new parallel is mounted, the

15 chips left between the jaws have to be removed (blown off), since the presence of chips under the parallel would alter the reference plane, thereby ruining the machining precision. For the same reason, chips adhering to the parallel have to be removed. Boring or drilling is espe-

20 cially complicated in this respect, since the parallel, which most often is made of hard metal, does not allow proper boring through the workpiece and there is a risk of tool breakage. Also, it will be appreciated that a great many parallels are needed for machining at angles.

25 The object of the present invention is to obviate these drawbacks of prior-art vices.

This object is achieved by the device as set forth in appended claim 1.

With the device according to the invention, different

30 supporting planes or reference planes are readily achieved by inserting pins in holes, producing the desired plane which then will not be altered by the presence of chips. -jj Through boring performed between pins is not impeded in any way. A pin (or pins) in a suitable hole(s) may form

35 a lateral stop(s), i.e. the device may give exact informa¬ tion on the position of the workpiece between the jaws, which is an advantage in serial machining. Another advan-

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tage provided by the device is the possibility of ensuring truly mirror-symmetrical machining.

An embodiment of the invention will be described in more detail below with reference to the accompanying draw- ings, in which

Fig. 1 is a front view of the inside of a vice jaw equipped with the orientating device according to the invention, and

Fig. 2 is a perspective view of the vice. The orientating device according to the invention includes two identical hard-metal plates 1 which are each fixed to a jaw 3 in a parallel vice, by means of counter¬ sunk bolts 2. The plates are formed with holes 4 of the same size. When the plates are mounted (or standing on the longitudinal edges on a horizontal supporting structure), the holes 4 form vertical columns S,A-E,A'-E ^I and horizon¬ tal rows a,b,a ^f ,b', the centres of the holes 4 in a centre column S, which defines a right/left mirror-symmetry plane, being however located half-way between two adja- cent, horizontal rows of holes. There is also top/bottom mirror symmetry. The spacing of the holes in each column and in the columns between themselves is constant (except at the fixing holes), while the spacing of the holes in the rows is such that the centre line between each hole in the centre column S and the closest holes in the closest- but-one horizontal row, e.g. Sy-Ab' and Sx-Aa', forms an angle of 45° with the horizontal. The corresponding angles for the centre line between the holes in the centre column S and stepwise further away in said closest-but-one row of holes are 30° (e.g. Sz-Bb), 20° (e.g. Sz-C'b) and 15°

(e.g. Sy-D'b')- These angles are the commonest machining angles. It will be appreciated that many other angles are conceivable in this embodiment (e.g. A'b-B'a').

The device comprises pins 5, fitting in and being removable from the holes 4, for supporting a workpiece (or workpieces) between the plate-equipped jaws of the vice.

It will be appreciated that two or more pins 5 in¬ serted into aligned holes 4 in the plates 1 can serve to support a workpiece between the jaws. The supporting sur¬ face defined by the pins may, according to requirements, 5 be horizontal and have different vertical positions (e.g. Ca-Aa; Cb'-Ab') _/ or be angled at 45°, 30°, 20° or 15° and have different vertical positions (e.g. Sx-Ba'; Sy-Bb'). As mentioned above, there are many other conceivable angle positions, which may be accounted for in tabular form.

10 A pin (or pins) inserted into a suitable hole (or holes) may also serve as a stop(s), so that the workpiece e.g. can be moved on its supporting surface (e.g. made up of two pins) into engagement against the stop(s), whereby each workpiece, e.g. in serial production, is given a pre-

15 determined position between the jaws. Further, the device permits machining for right/left symmetry (e.g. Sx-Ba'; Sx-B'a ¹ ), and machining with a 90° offset (e.g. Sx-Aa'; Sz-Ab). By these options, the cutter head need e.g. not be angled, as in conventional vices.

20 In the foregoing, it is implied that the plates are fixed to the jaws of conventional vices. Thus, the device according to the invention also includes a number of pins of different length, enabling the vice to clamp workpieces of different thickness. However, e.g. the stationary jaw

25 can be formed with through holes for receiving the pins, which would dispense with the need of different-sized pins.

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