Boring is a machining method for producing internal cylindrical shapes. Machining tools used are mostly either horizontal or vertical shanks. Machining is carried out with a tool adjusted to the shank of a machine tool in its one head, which tool comprises a usually bar-like body of the tool, directing forward from the shank. In the free end of the body there is one or several cutting blades working the piece by chipping and mounted radially with respect to the body. Usually the work piece has been adjusted to its place and the tool rotates while it performs the working motion.

Due to the projection like construction of the tool rather strong loads are directed to the shank and the machine tool, which is why the machine tools must be of sufficient stiff construction for limiting deformations and vibration such that desired working accuracy and surface quality are achieved.

It is recognized to employ solidly fixed to the tool or adjustable cutting blades in boring tools. Blades in tools equipped with adjustable cutting blades are usually adjustable radially with respect to the body. In these solutions, there are blade shafts, the blade element in which may be moved within defined adjustable limits in direction of the radius of the body linearly, when the locking screw meant for locking the blade element in its place has first been loosened. In addition, boring tools equipped with reversible blades exist. In recognized tools equipped with reversible blades there are blade elements, which have been adjusted in the free end of the body, reversible with respect to the longitudinal axel of the body, and to be locked by a locking screw or similar locking element to their place in desired position. Boring tools equipped with adjustable blades may also be with one or several blades. Usually one blade adjustable tool is easier and faster to adjust than a tool with two or several blades and therefore one-blade tools are usually employed in smaller series. Tools with two or several blades are slower to adjust than one- blade tools but by working speed clearly faster and are therefore more suitable than one-blade tools for producing bigger series. Common to all recognized manually adjustable boring tools is the fact that adjusting must be carried out in the blade end of the body, there, where the blade elements have been adjusted. Therefore, while changing the cutting diameter of blades the boring tool must usually be removed

from the machine tool. In addition, when holes of different diameters are produced by a boring tool to the same starting hole the tool must be removed from the hole (= remove from the hole by moving the shank of the machine tool) after every hole of different size and adjust the blade element again. These measures lengthen essentially the time spent for working comparing with the situation in which there is no need to change the cutting diameter between individual boring functions.

Furthermore, for example, while making back borings to the backside through the starting hole in a work piece the boring tool must be moved in the direction of the radius of the hole when the tool is brought through the hole. This is often slow and cumbersome and requires a machine tool in which there is a possibility of moving the shank transversely.

The purpose of the invention is to produce a multi-function boring tool, with which the earlier mentioned problems related to presently known manually adjustable boring tools are eliminated. Especially, the purpose of the invention is to produce a boring tool, the blades of which can be adjusted without removing the boring tool from the shank of a machine tool and with which it is possible to produce holes of different size to the same starting hole without removing the boring tool from the hole to be worked for adjusting the cutting diameter. In addition, the purpose of the invention is to produce a boring tool, which may be taken away from the starting hole in the work piece without removing the boring tool in the direction of the radius of the hole while working a back boring.

The objective of the invention is accomplished by a boring tool, the characteristics of which are presented in the claims.

Characteristic to the multi-function boring tool in accordance with the invention is the fact that the multi-function boring tool comprises an adjusting mechanism, which includes an adjusting part reaching a distance from the free end of the body to the direction of the fixing part for adjusting the cutting diameter of the blade elements. The blades of a multi-function boring tool equipped with such an adjusting mechanism may be adjusted without removing the multi-function boring tool from the shank of a machine tool. Due to this, remarkable amount of time is saved, for example, when working a piece to which lots of holes of different size are made. In addition, the blade elements of this kind of multi-function boring tool may most often be adjusted without taking the tool through the work piece, while the adjusting part, carrying out the adjusting, projects outside the hole to be worked.

This characteristic of the multi-function boring tool in accordance with the invention also saves time and reduces costs of boring work of a work piece.

In an advantageous application of the invention, the body of a multi-function boring tool is round by cross-section and the adjusting part is a sleeve-like object reaching to the part of the fixing part side of the body from the free end of the body, which sleeve-like object has been adjusted inside the adjusting part reversible with respect to the adjusting part. Due to this kind of adjusting part, the adjusting mechanism needed for adjusting the blade elements may be simple, exact and easy to use. In addition, due to this kind of adjusting part the multi-function boring tool may be produced of the same size of an equivalent recognized boring tool by outer diameter without diminishing the stiffness and the durability of the body.

In the second advantageous application of the invention, the adjusting mechanism comprises guiding elements for moving the blade elements by turning the adjusting part with respect to the body. An adjusting mechanism based on this kind of guiding elements can be easily made simply and reliably functioning by construction. In addition, carrying out adjusting with this kind of adjusting part may be realized quickly, because the adjusting movement of blade elements may be realized to happen with a relatively small turning movement. Furthermore, locking of this kind of adjusting mechanism such that the cutting diameter of blade elements is in desired limit between the extreme limits of the adjusting scale may be carried out with a relatively simple locking mechanism, which is easy to realize.

In the third advantageous application of the invention, guiding elements are pivots and the blade elements include guiding grooves placed at the guiding elements for moving the blade elements by means of guiding elements placed in the guiding grooves. A turning mechanism functioning in this way is simple, reliably functioning, and requires only little space, as well as it is possible to be made to function with a small adjusting movement. Due to this, the adjusting of blade elements may be carried out quickly and easily. In addition, due to this kind of adjusting mechanism it is possible to move several blade elements with one adjusting part at the same time, that is, due to the adjusting part, the multi-function boring tool may be changed into multi-cutting without increasing the time spent on adjusting.

In the fourth advantageous application of the invention, the adjusting part includes a locking element mounted on the part in the fixing part side of the body for locking the adjusting part and the blade elements to their place in the desired point. Due to this kind of locking element the locking of the adjusting part in its place may be carried out without taking the blade elements through the work hole since the

locking element has been placed such that it remains outside the work piece while the free end of the body and the blade elements are in the work hole.

In the fifth advantageous application of the invention, the blade elements have been fixed to holes made in the free end of the body reversible by screws. In addition, there are space sleeves supported to shoulders made to the holes mounted between the screws and the blade elements for eliminating excessive tightening of the blade elements. In those applications where the blade elements have been fixed to the body reversible, it is advantageous if the fixing is such that the blade elements may turn relatively sensitively, but, however, in rather clearanceless way such that the blade elements may not move and vibrate during working. The screw fixing may be released and the tightness may easily be adjusted. Due to space sleeves, the screws may be tightened sufficiently without danger that the blade elements would be pressed too tight against the free endd of the body, in which case adjusting with the adjusting part would not be possible anymore.

In the sixth advantageous application of the invention, the multi-function boring tool comprises a shank part, mounted in a hole mainly longitudinal in the direction of the body, and made inside the body to be locked in place and movable in the direction of the hole. In the end of the free end side of the body of the shank part there is a supporting flange for eliminating clearances between the free end of the body and the blade elements by means of the shank part. Clearances very easily appear/are created between the blade elements and the free end of the body because the blade elements are adjusted to the free end of the body movably. To achieve good working accuracy, the blade elements should stay as exactly as possible in place during working. When the shank part is adjusted to the body as described earlier, the blade elements are possible to be supported at their outer edge and pressed against the free end of the body such that clearances of the adjusting of blade elements are eliminated and movements and vibrations during working are prevented. In addition, with this kind of shank part, liminating clearances and pressing of blade elements in place may be realized to be controlled from the fixing part side of the body, in which case even these measures do not require taking the free end of the body and the blade elements through the hole of the work piece or removing the multi-function boring tool from the shank of the machine tool.

In the seventh advantageous application of the invention the shank part and hole formed in the body for it reach to the end of the fixing part side of the body and the end of the fixing part side of the body includes a bevel screw threaded to a hole reaching to the shank part and a bevel hole formed at this point of the shank part,

which bevel hole has been shaped such that the bevel screw while tightened moves the shank part in the direction of the fixing part and such tightens the supporting flange against the blade elements. By means of this kind of shank part and bevel screw tightening included in it eliminating and tightening of clearances between the blade elements and the free end of the body as well as loosening of tightening may be realized to be controlled by means of one screw in the end of the fixing part of the body. This makes eliminating and tightening of clearances easy and convenient, which decreases time for adjustments and thus saves costs of boring work.

Next, the invention will be explained in more detail with reference to the accompanying drawings, in which, Figure 1 illustrates a longitudinal cross section of a multi-function boring tool in accordance with the invention, figure 2 illustrates a multi-function boring tool in accordance with figure 1 viewed from ahead with the cutting diameter adjusted to minimum, and figure 3 illustrates a multi-function boring tool in accordance with figure 1 viewed from ahead with the cutting diameter adjusted to maximum.

The multi-function boring tool in accordance with figures 1-3, equipped with reversible cutting blades comprises a fixing part 1, the body 2 mounted to the fixing part 1 and blade elements 4 mounted adjustable to the free end 3 of the body. In addition, the multi-function boring tool comprises the adjusting mechanism of the blade elements 4 for adjusting the cutting diameter of blade elements from the fixing part 1 side part 19 of the body. The adjusting mechanism of the blade elements comprises, in this application, an adjusting part 5, guiding pivots 6 of the adjusting part, guiding grooves 7 of the blade elements, locking screw 8 of the adjusting part and the shank part 14, a supporting flange 15 in the end of the shank part and a bevel screw 16 of the shank part.

The fixing part 1 is in the application in accordance with figure 1 a recognized fixing conoid (for example in accordance with ISO 50). By means of this kind of fixing part, the multi-function boring tool may be mounted to a shank of a boring machine sufficiently stiff and very durable in the place but, however, relatively easy to be removed. The construction of the fixing part 1 depends on the machine tool in use. Therefore, the body 2 of the multi-function boring tool adjusted to the fixing part may be removed from the fixing part and the fixing part may be changed to another fixing part, which may be a fixing conoid or some other fixing part suitable for the machine tool in use.

The body 2 is a round by cross section, bar-like object, which has been adjusted to the fixing part as illustrated in figure 1. The adjusting of the body to the fixing part 1 has been realized, in this case, such that in the part 19 of the fixing part side there is a fixing end 20, which has been adjusted to a fixing hole 22 shaped in the fixing part and fixed to its place with screws (not illustrated in figures 1-3). In the part 19 of the fixing part side of the body there is, moreover, a shoulder 21 against which the fixing part 1 has been tightened for improving the stiffness of the joint between the fixing part and the body. The diameter of the body is constant from the shoulder 21 forward until the free end 3. At the middle point of the cross section of the body there is a centre hole 13 longitudinal with the body reaching from the free end 3 approximately to the shoulder 21 for the shank part 14 to be mounted inside the body and the thread part 24. On the free end side of body of the shoulder 21 there is a groove hole 23 reaching from the surface of the body to the centre hole 13 for the locking screw 8 of the adjusting part 5 to be adjusted on the body. The groove hole 23 has been shaped such that it enables the screw 8 to turn about 60° around the central axis of the body, in which case the adjusting part 5 adjusted on the body may be turned in this angle when the screw 8 has been loosened. There is a radial hole 17 reaching from the surface of the body to the centre hole 13 in perpendicular direction against the plane in the figure slightly to the direction of the free end of the body from the groove hole 23, for the bevel screw 16 meant for adjusting and locking of the shank part 14. In addition, outside the hole 13 in the free end 3 of the body there are three holes 9 of the fixing screw 10 of the blade elements 4. These holes are placed in accordance with figures 2 and 3 in 120 ° intervals viewed from the body end and in the beginning section of these holes there is a bigger section by diameter, which section ends at the shoulder 11. Further, on the upper surface of the shoulder 21 of the body there is a cutting diameter scale marked, from which the cutting diameter of the multi-function boring tool may be read by means of indicating line marked on the edge of the adjusting part (indicating line and cutting diameter scale are not illustrated in figures 1-3).

The application of the multi-function boring tool in accordance with the invention illustrated in figures 1-3 is three cutting. Therefore, in this application there are three blade elements. The blade elements have been mounted to the holes 9 placed in the free end 3 of the body 2 through holes 27 such that the angle between the blades is 120°. Between the blade elements 4 and the screws 10 there are space sleeves 12, which tighten while tightening the screws 10 against the shoulders 11 in the holes 9. In this way the tightening of blade elements against the free end 3 of the body is prevented and, at the same time, secured that the blade elements are able to

turn round their fixing point easily enough. There are fixing elements near the peak of the blade elements for mounting replaceable blade parts to the peaks of the blade elements. Blade parts and their mounting are earlier recognized items and, therefore, they are not illustrated in figures 1-3.

Between the fixing screws 10 and the peaks of blade elements at the point of adjusting part 5, there are guiding grooves 7. They are shaped as presented in figures 2 and 3 curved such that guiding pivots 6 adjusted to the guiding grooves 7 and mounted to the end of the free end side of the body of the adjusting part 5 turn the blade elements 4 from the position in figure 2 to the position in figure 3 when the adjusting part 5 is turned such that the guiding pivots 6 move the distance allowed by the guiding grooves (e. g. 60°). The guiding grooves have been made such deep that the ends of the guiding pivots keep the blade elements in place in spite of loads directed to the blade elements.

The adjusting part 5 is a round by cross section, sleeve-like object, reaching from the free end 3 of the body to the shoulder 21, inside which object the body 2 is suitable almost without clearance, but sensitively moving and reversible (e. g. the tolerances of the body and the adjusting part form a suitable clearance fitting). Both ends of the adjusting part are bigger by outer diameter, as illustrated in figure 1, than the rest of the adjusting part. On the section of the fixing part 1 side, which is bigger by outer diameter, there is, with respect to the adjusting part, a longitudinal hole 25 for the locking screw 8, and in the section of the free end side of the body of the adjusting part, which part is bigger by outer diameter than the other parts, there are three holes 26 in 120° intervals longitudinal with the adjusting part for guiding pivots 6. The hole 25 is placed at the groove hole 23 when the adjusting part 5 has been mounted in place. The upper part of the hole 25 comprises a mortise, with which the head of the locking screw 8 has been sank inside the adjusting part 5 as presented in figure 1. The locking screw 8 is an allen screw, which goes through the groove hole 23 until the treaded object 24 in the center hole 13, in which threaded object there is a hole suitable to the locking screw. The guiding pivots 6 mounted to the holes 26 reach outside the free end of the body until the guiding grooves 7 placed in the blade elements. The guiding pivots 6 have not been fixed in any way in this application, while they stay between the guiding grooves 7 and the holes 26 when the blade elements are fixed in place.

The shank part 14 meant for tightening the blade elements 4 to their place has been adjusted to the centre hole 13 of the body as presented in figure 1. In the end of the shank part, there is a supporting flange 15, which reaches to the recess 28 reaching

above the heads of the fixing screws 10 of the blade elements as presented in figure 1. The heads of the fixing screws 10 have been sank inside the blade elements such that the supporting flange touches the bottom of the recess 28 but not the heads of the fixing screws 10. Therefore, while moving the shank part 14 inside the body in direction of the fixing part 1 the inner surface of the supporting flange 15 presses the blade elements against the free end 3 of the body. There is a conical hole 18 on the fixing part side of the shank part 14 (at the point of the hole 17 on the body part), into which the conical head of the bevel screw 16 threaded to the hole 17 on the body pushes while tightened. The conical hole 18 has been shaped inclined to the direction of the free end of the body, in which case the head of the bevel screw 16 moves the shank part inside while the conical screw is tightened. Therefore the supporting flange 15 may be tightened against the blade elements by tightening a bevel screw 16 such that the shank part 14 and the supporting flange 15 included in it as well as the bevel screw 16 mounted in the body form thus at the blade elements a tightening system which may be guided from the fixing part 1 side part of the body.

While adjusting the blade elements 4 of the multi-function boring tool illustrated in figures 1-3 first the bevel screw 16 and the locking screw 8 of the adjusting part are loosened. After this, the adjusting part 5 is turned clockwise or anticlockwise depending on whether the cutting diameter of the blade elements is desired to be made larger or smaller. While turning clockwise the cutting diameter gets larger and turning anticlockwise smaller. Adjusted cutting diameter may be read from a cutting diameter scale marked to the shoulder 21 of the body part 2 by the indicating line marked to the fixing part 1 side end of the adjusting part 5. After the desired cutting diameter has been adjusted, first the locking screw 8 is tightened and after this the bevel screw 16, which tightens the blade elements tight against the free end of the body. There is no need to remove the multi-function boring tool from the shank of a machine tool or even remove from the work piece while adjusting the cutting diameter of the blade elements, while adjusting and locking at place of the blade elements may be carried out at the fixing part side end, which is not usually inside the work piece even during working.

A multi-function boring tool in accordance with figures 1-3 may be employed as currently known boring tools for working inner cylindrical surfaces. While working a usual boring in a hole, the blade elements are adjusted to a cutting diameter equivalent to the inner diameter of the designed boring. In the multi-function boring tool in accordance with figures 1-3 the adjusting distance of cutting diameter is 100

- 130 mm. After adjusting and locking in place the blade elements, the boring is carried out in recognized way.

While working so-called back boring through a starting hole on the backside of the object, the blade elements are first adjusted to suit the starting hole clearly smaller than the designed back boring. After this, the head of the boring tool is pushed through the starting hole by moving the shank of the machine tool in longitudinal direction of the boring tool such that the blade elements are entirely on the backside of the workpiece. Next, the blade elements are adjusted to correspond to the cutting diameter of the designed back boring. After this, the work is started by starting the revolving motion of the boring tool and moving the multi-function boring tool back in the direction of the starting hole of the workpiece, in which case the blade elements start to work the designed back boring on the backside of the workpiece.

When the desired depth of the back boring has been achieved, the blade elements are moved back to the backside of the workpiece and the shank of the machine tool is stopped. After this the blade elements are adjusted again to fit through the starting hole, after which the head of the boring tool may be moved through the starting hole from inside the work piece.

With a multi-function boring tool in accordance with figures 1-3, it is possible to work also many other such holes or inner cylindrical surfaces, which have borings of different size. Usually, it is enough after each boring work to stop the shank of the machine tool and adjust the cutting diameter of blade elements. It is not necessary to remove the multi-function boring tool from the shank of the machine tool and not even to (entirely) move the shank from inside the work piece. This saves a considerable amount of time in case the hole to be worked includes several borings of different size.

The multi-function boring tool in accordance with the invention may be produced in many ways differing from the application in accordance with figures 1-3. The parts included in the multi-function boring tool, such as the shape, length of the body part and, among other things, the adjusting of the body part to the fixing part (of which only one example was presented earlier) may vary. There may be a varying quantity of blade elements and the adjusting distance may vary. For example, the adjusting mechanism in accordance with figures 1-3 based on reversing with respect to the body adjusting part may be produced in principle regardless of the quantity of blade elements. The size of the free end of the body part, in the first place, appears to be the limiting factor. It is possible to mount more blade elements to a multi- function boring tool of a big size than of a smaller size. In the application in

accordance with figures 1-3 the adjusting of blade elements is carried out by turning the blade elements. Alternatively, the adjusting of blade elements may be carried out such that, for example, blade elements are moved linearly in direction of the radius of the body. The adjusting mechanism employed in this kind of solution may be produced, for example, with a longitudinal in the direction of the body-revolving axle, mounted inside the body, and a transmission mechanism moving blade elements, which mechanism has been mounted in the end of the revolving axle. A suitable transmission mechanism may be formed of, for example, a worm gear mounted in the revolving axle, which worm gear moves thread bars in blade elements and the blade elements such that their cutting diameter changes. The motion of the revolving axle may be produced, for example, with a scale screw, sank to the body part to the fixing part side or with sleeve-like turning object, turning the revolving axle and adjusted on the body.

It is obvious that many recognized parts, included in the multi-function boring tool may be realized in different ways and/or differing by construction. Such, for example, the construction of blade elements, the possible adjusting of blade parts may vary depending, among other things, on for what kind of materials and working speeds the tool in question has been meant. Further, the multi-function boring tool ought to be suitable for as many as possible different machine tools and, therefore, the fixing part in it may also differ from the fixing conoid in application in accordance with figures 1-3.

The invention is not limited to the presented advantageous application but it can vary within the frames of the idea of the invention formed in the claims.