PRIOR ART A plurality of different types of systems and devices for cutting machining in the form of milling are known in the prior art. According to conventional technology milling heads with bits for milling by clockwise rotation are used, after which the milling head is worn out and discarded. Also milling heads with detachable bits and milling heads for connection with cartridges with bits are known. One such type of system is disclosed in US4330227. The system disclosed in US4330227 comprises a milling head connectable to a milling machine, the milling head being provided with detachable cartridges for receiving and holding bits for milling. The milling head is connectable to different types of cartridges for holding bits in different angles. When the bits have been used for milling by clockwise rotation the bits are considered worn out and are discarded.

Another system for cutting machining is described in US5788426. US5788426 discloses a milling head being connectable to a milling machine, the milling head being provided with detachable cartridges for different types of bits. The milling head according to US5788426 is connectable with cartridges for machining by clockwise rotation as well as cartridges for machining by counter-clockwise rotation.

A disadvantage of systems for cutting machining according to prior art is that the working expenses are relatively high. A problem with such prior art systems for cutting machining is that the environmental influence is relatively high.

Another disadvantage of such systems for cutting machining according to prior art is that they are difficult to use within different types of cutting ma- chining due to their structure.

Another problem with such systems for cutting machining according to prior art is that they are limited to a specific type of use due to the lack of flexibility of their structure.

SUMMARY OF THE INVENTION

An object of the present invention is to avoid the disadvantages and problems of the prior art. The system and the method according to the invention result in that the bits are used to a higher extent than in systems of prior art, wherein the invention results in higher cost efficiency and reduced environmental influence compared to prior art systems.

The present invention comprises a system for cutting machining of objects, comprising a bit for cutting machining in the form of milling, and a cartridge for receiving and holding the bit by means of a fastening device, wherein the cartridge is detachably connectable to a milling head by means of a fastening means, characterised in that the milling head is arranged for milling in a counter-clockwise direction of rotation, and that the cartridge is detachably connectable also with a lathe tool holder for receiving the cartridge, wherein at least one portion of the bit for milling can be used also for cutting machining in the form of lathe machining. Hence, the cartridge, the milling head and the lathe tool holder form the system according to the invention. The system according to the invention results in efficient use and re-use of bits, so that the bits worn out in respect of milling in clockwise rotation are useful both within milling in counter-clockwise direction and within lathe ma- chining. For example, the bits worn out in respect of milling in a counterclockwise direction are useful within lathe machining. Hence, bits, which previously were considered worn out, can be re-used in a simple and effective manner by means of the system according to the invention, which result in improved cost efficiency and reduced environmental influence.

The cartridge can be provided with a recess for receiving a portion of the bit, which recess partially encloses the bit and supports the bit from at least three sides. The recess can comprise a bottom for supporting the bit, for example through a conventional washer. Further, the recess can comprise a first recess side for engaging a first side of the bit, a second recess side for engaging a second side of the bit, and a third recess side for engaging a third side of the bit, so that the bit is supported by the bottom, and is supported from three different recess sides of the cartridge. In this way a stable and secure fastening of the bit can be obtained for different types of cutting machining.

The bit can be provided with at least one right milling portion, at least one left milling portion and at least one substantially straight side. The sub- stantially straight side can be useful for lathe machining, such as for chamfering and planing work. For example, the bit is an octagonal indexable insert or any other type of conventional bit. The bit can be worn out in respect of milling in a clockwise direction of rotation, i.e. right hand milling.

The lathe tool holder can comprise a first cavity for receiving the car- tridge in a first direction, and a second cavity for receiving the cartridge in a second direction, so that the cartridge is detachably connectable with the lathe tool holder in at least two different directions. As a result a bit can be used in an effective and flexible way for different types of lathe machining work. Each cavity can be formed with a bottom surface for supporting the cartridge, a first side surface for supporting a first side of the cartridge and a second side surface for supporting a second side of the cartridge. In this way a stable and secure connection between the lathe tool holder and the cartridge can be obtained.

The milling head can be provided with an aperture for receiving and partially enclosing the cartridge, so that the cartridge can be inserted into the aperture for connection to the milling head. The aperture can be defined by an inner side, an upper side, a first side and a second side opposite the first side for supporting a cartridge arranged in the aperture, so that the cartridge is supported from at least four sides. In this way a stable and secure connection is obtained between the milling head and the lathe tool holder. The cartridge can be connectable with the milling head and the lathe tool holder by means of a fastening means, such as a screw, wherein the same fastening means can be used to connect the cartridge with the milling head and the lathe tool holder.

The invention also relates to the use of the above system for re-using bits worn out in respect of milling in clockwise direction of rotation. The invention also relates to a method for cutting machining of objects, comprising the steps of a) connecting a bit, which bit is worn out in respect of milling in a clockwise direction of rotation, with a cartridge for receiving and holding the bit, b) connecting the cartridge with a milling head for receiving and holding the cartridge and the bit arranged in the cartridge, c) performing cutting machining in the form of milling in a counterclockwise direction of rotation by means of the bit arranged in the cartridge, d) detaching the cartridge from the milling head, e) connecting the cartridge with a lathe tool holder, and f) performing cutting machining in the form of lathe machining by means of the bit arranged in the cartridge.

The steps in the method can be performed in said order, wherein the bit worn out in respect of milling in counter-clockwise direction of rotation can be used for different types of lathe machining work, such as exterior and interior planing and chamfering work.

Further characteristics and advantages of the present invention will become apparent from the description of the embodiments below, the appended drawings and the dependent claims. SHORT DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail with the aid of embodiments with reference to the appended drawings, in which

Fig. 1 is a schematic perspective view of a cartridge for receiving a bit according to one embodiment of the present invention,

Fig. 2 is a schematic perspective view of a bit which is connectable to the cartridge according to one embodiment of the present invention,

Fig. 3 is a schematic exploded view illustrating connection of the bit of Fig. 2 with the cartridge of Fig. 1 ,

Fig. 4 is a schematic perspective view of the cartridge with the bit,

Fig. 5 is a schematic perspective view of a milling head according to one embodiment of the invention,

Fig. 6 is a schematic perspective view showing the mounting of a cartridge in the milling head of Fig. 5 according to one embodiment of the invention,

Fig. 7 is a schematic perspective view of the milling head and cartridges connected to the milling head, the cartridges being provided with bits for cutting machining by milling in a counter-clockwise direction of rotation according to one embodiment of the present invention,

Fig. 8 is a schematic perspective view of a lathe tool holder according to one embodiment of the present invention,

Fig. 9 is a schematic perspective view of a lathe tool holder connected to a cartridge holding a bit according to one embodiment of the present invention, and Fig. 10 is a schematic perspective view of a lathe tool holder connected to a cartridge holding a bit according to one embodiment of the present invention.

THE INVENTION

Referring to Figs. 1-4 a cartridge 10 for receiving a bit 11 is illustrated schematically, wherein the cartridge 10 according to one embodiment of the invention is illustrated in Fig. 1 , the bit 11 according to one embodiment of the invention is illustrated in Fig. 2, mounting of the bit 11 in the cartridge 10 is illustrated in Fig. 3 and the cartridge 10 with the bit 11 is illustrated in Fig. 4. The cartridge 10 comprises a recess 12 for receiving the bit 11 , so that the bit 11 can be inserted into the recess 12 and detachably connected therewith. For example, the recess 12 is formed to receive a washer 13 and a bit 11 arranged on the washer 13, as is disclosed in Fig. 3 and Fig. 4. For example, the washer 13 is a conventional washer. For example, the bit 11 is detachably connectable with the cartridge 10 by means of a fastening device 14, such as a conventional bit screw which is inserted through a hole 15 in the bit 11 and through a hole 16 in the washer 13 to be screwed into a threaded hole 17 in the cartridge 10. Alternatively, the fastening device 14 is arranged as a clamp for clamping the bit 11 towards the cartridge 10. Alternatively, the fastening device 14 is arranged in another way, such as a magnet or similar, wherein the bit 11 is detachably connectable to the cartridge 10.

The cartridge 10 is adapted to the bit 11 , wherein the recess 12, for example, is adapted for a specific type of bit 11. For example, the cartridge 10 is arranged for supporting the bit 11 from at least three or four sides when the bit 11 is connected therewith. When the bit 11 is arranged in the recess 12 the bit is supported from a bottom 18 in the recess 12 through the washer 13. Further, the bit 11 is supported from a first recess side 19, a second re- cess side 20 opposite the first recess side 19 and a third recess side 21 connecting the first recess side 19 and the second recess side 20. Alternatively, the cartridge 10 comprises a first recess side and a second recess side arranged at an angle to the first recess side forming a V-shape. Alternatively, the recess 12 is formed with any other form to be adapted to the present type of bit 11.

The cartridge 10 according to the embodiment illustrated in the drawings comprises a through bore 22 for a fastening means 23, which is de- scribed in more detail below.

For example, the bit 11 is a conventional bit for cutting machining in the form of milling. For example, the bit 11 comprises at least one right milling portion 24 for milling by clockwise rotation, so called right hand milling, and at least one left milling portion 25 for milling by counter-clockwise rota- tion, so called left hand milling. In the illustrated embodiment the bit is octagonal, wherein the bit 11 is formed with four right milling portions 25a-d and four left milling portions 25a-d. Alternatively, the bit 11 is formed with any other number of milling portions 24, 25. Further, the bit 11 is formed with at least one substantially straight portion 26. In the illustrated embodiment the bit 11 is formed with four substantially straight sides 26a-d. Alternatively, the bit 11 is formed with any other number of substantially straight sides 26. For example, the straight side 26 extends from the first right milling portion 24a to the second left milling portion 25b. The straight side 26 is useful for performing cutting machining in the form of lathe machining, such as chamfering and planing work. For example, the bit is an indexable insert, such as an octagonal indexable insert. In the illustrated embodiment, the bit 11 is formed with a hole 15 for a bit screw. Alternatively, the bit 11 is arranged without the hole 15, wherein the bit 11 is connectable to the cartridge 10 by means of a clip, clamp or similar. With reference to Figs. 5-7 a milling head 27 according to one embodiment of the present invention is illustrated. The milling head 27 comprises a conventional attachment 28, such as an attachment according to ISO-standard, for connection to a spindle or similar of a machine for cutting machining in the form of milling, which machine for example is a conventional milling machine and is not illustrated in the drawings. The milling head 27 according to the invention is arranged for milling in a counter-clockwise direction of rotation, as illustrated by means of the arrow A in Fig. 7. For example, the milling head 27 is formed in metal. Alternatively, the milling head 27 is formed in any suitable plastic material or similar.

The milling head 27 is formed with at least one aperture 29 and suitably a plurality of apertures 29, wherein each aperture 29 is arranged for re- ceiving a cartridge 10 holding a bit 11 , so that the cartridge 10 with the bit 11 can be inserted into the aperture 29 and be detachably connected with the milling head 27 by means of the fastening means 23. The aperture 29 is formed for receiving and partially enclosing the cartridge 10, so that the cartridge 10 with the bit 11 can be inserted into the aperture 29 and be detach- ably connected to the milling head 27. The aperture 29 is arranged so that a cartridge 10 arranged in the aperture 29 is supported from at least three sides and more suitably four sides. In the illustrated embodiment the aperture 29 is defined by an inner side 30, an upper side 31 , a first side 32 and a second side 33 opposite the first side 32 for supporting an cartridge 10 arranged in the aperture 29. The inner side 30 is formed with at least one hole 34, such as a threaded screw hole, for receiving the fastening means 23. Alternatively, the inner side and the cartridge 10 are formed with two holes 34, so that the cartridge 10 can be connected to the milling head 27 by means of two fastening means 23. According to one embodiment of the milling head 27 the inner side 30 is arranged also with at least one hole for receiving a guide pin or similar to ensure the position of the cartridge 10, which is not illustrated in the drawings.

With reference to Figs. 8-10 a lathe tool holder 35 is illustrated schematically according to one embodiment of the invention. The lathe tool holder 35 is arranged to be detachably connected to a lathe machine for cutting machining in the form of lathe machining, which lathe machine not is illustrated in the drawings. Further, the lathe tool holder 35 is arranged to be detachably connected to at least one cartridge 10 holding a bit 11. For example, the cartridge 10 is detachably connectable to the lathe tool holder 35 by means of the fastening means 23. The lathe tool holder 35 is formed in metal or other suitable material. The lathe tool holder 35 comprises a first cavity 36 for receiving a cartridge 10 holding a bit 11 in a first direction, as disclosed in Fig. 9, and a second cavity 37 for receiving a cartridge 10 holding a bit 11 in a second direction, as disclosed in Fig. 10. For example, the first direction is arranged at an angle to the second direction. For example, the first direction is arranged substantially perpendicular to the second direction. For example, the first cavity 36 is arranged for receiving the cartridge 10 in the first direction, wherein the bit 11 projects from the lathe tool holder 35 in the first direction, such as in a direction perpendicular to the longitudinal direction of the lathe tool holder 35. For example, the second cavity 37 is arranged for receiving the cartridge 10 in the second direction, wherein the bit 11 projects from the lathe tool holder in the second direction, such as a direction along the longitudinal direction of the lathe tool holder 35. For example, the first cavity 36 is arranged for receiving the cartridge 10 in a direction for internal lathe machin- ing, wherein the first direction is a direction suitable for internal lathe machining. For example, the second cavity 37 is arranged for receiving the cartridge 10 in a direction for external lathe machining, wherein the second direction is a direction suitable for external lathe machining.

In the illustrated embodiment the lathe tool holder 35 is elongated, wherein the first cavity 36 is arranged in a first end 38 of the lathe tool holder 35 and the second cavity 37 is arranged in an opposite second end 39 of the lathe tool holder 35. The cavities 36, 37 are arranged for supporting the bottom and two sides of a cartridge 10. Hence, the first cavity 36 is arranged with a bottom surface 40, a first side surface 41 and a second side surface 42 arranged in an angle to the first side surface 41 for engaging the cartridge 10. The first side surface 41 extends substantially in the longitudinal direction of the lathe tool holder 35 while the second side surface 42 extends substantially perpendicular to the longitudinal direction of the lathe tool holder 35. The second side surface 42 of the first cavity 36 is for example provided with a hole 43 for receiving the fastening means 23 for detachable connection of the cartridge 10 with the lathe tool holder 35 in the first direction, as illustrated in Fig. 9, wherein the bit 11 projects from the lathe tool holder 35 in a direction substantially perpendicular to the longitudinal direction of the lathe tool holder 35. For example, the hole 43 in the second side surface 42 of the first cavity 36 extends in the longitudinal direction of the lathe tool holder 35. The second cavity 37 is arranged with a bottom surface 44, a first side surface 45 and a second side surface 46 arranged in an angle to the first side surface 45. The first side surface 45 extends substantially in the longitudinal direction of the lathe tool holder 35 while the second side surface 46 extends substantially perpendicular to the longitudinal direction of the lathe tool holder 35. The first side surface 45 of the second cavity 37 is for example provided with a hole 47 for receiving the fastening means 23 for detachable connec- tion of the cartridge 10 with the lathe tool holder 35 in the second direction, as illustrated in Fig. 10, wherein the bit 11 projects from the lathe tool holder 35 in the longitudinal direction of the lathe tool holder 35. For example, the hole 47 in the first side surface 45 of the second cavity 37 extends in a direction perpendicular to the longitudinal direction of the lathe tool holder 35. The cartridge 10, the milling head 27 and the lathe tool holder 35 form a system for efficient use of bits 11 , wherein the bits worn out in respect of milling in clockwise rotation are useful both for milling in counter-clockwise direction and for lathe machining. Milling by clockwise rotation, so called right hand milling, results in that the right milling portions 24 of a bit 11 are worn. The bits 11 worn out in respect of milling in clockwise rotation are connect- able with the cartridge 10 according to the invention. The cartridge 10 is de- tachably connectable with the specially formed milling head 27 for milling in counter-clockwise direction, wherein the left milling portions 25 of the bit 11 are useful for milling. The cartridge 10 is also connectable with the specially formed lathe tool holder 35, wherein the straight sides 26 of the bit are useful for cutting machining in the form of lathe machining. Hence, bits 11 , which are considered worn out, can be re-used in a simple and efficient manner by means of the system according to the invention.