The present invention relates to an apparatus for manipulating, such as machining and especially cutting tubular and round-bar type objects. A variety of tools are known from the prior art for machining, such as for cutting, a tubular or round-bar type piece. One exemplary tool of the prior art is an apparatus comprising a clamping mechanism adapted to be fastened to the workpiece rotata bly there around. The clamping mechanism has attached thereto a tool unit, which is provided with adjustment means for displacing said tool unit relative to the clamp- ing mechanism towards or away from the workpiece. The clamping mechanism in cluded a frame element and first and second arms extending therefrom, the arms being articulated at one end to the frame element of the clamping mechanism and each arm has its free end fitted with a bearing axle, which is provided with at least one bearing wheel. The clamping mechanism has its frame element provided in a rotatable and axially immobile fashion with a threaded shaft, whose first end has a right-handed thread provided with a first nut and whose second end has a left- handed thread provided with a second nut. The threaded shaft is provided with a member for rotating the threaded shaft, and the first arm and the first nut are articu lated to each other by means of a first suspension arm and the second arm and the second nut are articulated to each other by means of a second suspension arm. The suspension arms, or the frame element itself, may advantageously also be equipped with bearing wheel or wheels. This way three or four contact points via the bearing wheels can be provided between the clamping mechanism and the tubular or round- bar type piece clamped with the mechanism. These kinds of apparatuses are known from publications WO 02/02271 and WO 2004/013623, for example.

During or after the cutting of a tubular or round-bar type object a bevel surface is typically formed on the cut surface, which bevel surface is utilized in connecting the cut piece to another tubular piece, such as in welding in case of metal pipes or other metal tubular pieces.

Since the adjustable clamp mechanisms of the above discussed prior art machining apparatuses allows machining of variable diameter tubular pieces, the blade of the machining apparatus is subjected to differing wear and tear during the usage of the apparatus, which can in many cases decrease the lifetime of the blade. The present invention provides a solution for increasing the lifetime of the blade of such an apparatus for machining tubular or round-bar type objects, wherein the maximum depth for the blade during the machining process is adjustable. This al lows the maximum machining depth of the blade to be properly adjusted and opti mized for different diameter tubular pieces, thus allowing more proper positioning of the blade in relation to the tubular object during machining, which extends the life time of the machining blade.

The apparatus of the invention for manipulating, such as machining and especially cutting, tubular and round-bar type pieces, comprises a clamping mechanism adapted to be fastened to said workpiece rotatably therearound and said clamping mechanism configured to be attached thereto a tool unit with a rotary blade, and first adjustment means for displacing said tool unit relative to the clamping mechanism towards and away from the workpiece, wherein the apparatus comprises second adjustment means for adjusting the extreme position for the displacement of the tool unit and especially its rotary blade towards the workpiece.

In an embodiment of the invention the second adjustment means comprise a hinged connection arranged between the clamping mechanism and the tool unit allowing the adjustment of the position of the tool unit in relation to the clamping mechanism, and setting means for setting the extreme position of the tool unit towards the work- piece.

Alternatively or additionally in relation to the previous embodiment the second ad justment means may comprise a plate member to which plate member the tool unit is connected, and in which plate member the hinged connection is located at one edge area and the setting means are located substantially at the opposite edge area of the plate member.

The setting means may comprise a threaded bolt passing through part of the tool unit or the plate member via a threaded hole. Alternatively, the setting means may comprise an adjustment surface with preset locations connected to the clamping mechanism, and a locking member connected to the tool unit for setting the position of the tool unit in relation to the clamping mechanism with the preset locations in the adjustment surface.

In an embodiment of the apparatus of the invention at least the rotary blade, prefer ably the whole tool unit, is connected to the rest of the apparatus so, that the angle of the rotary blade in relation to the length axis of the workpiece to be manipulated is adjustable. This adjustability allows the cut, especially in the cases where a bev elling is simultaneously formed, made in the workpiece to be more exactly perpen dicular in relation to its length axis.

In an embodiment of the apparatus of the invention the clamping mechanism is ad justable for workpieces of different diameter.

The adjustable clamping mechanism may comprise:

- a frame element,

- first and second arms extending from the frame element, said arms being coupled at one end to the frame element of the clamping mechanism and each arm has its free end fitted with a contacting member configured to contact the surface of the workpiece,

- two movable guiding members to which said arms are coupled so that when said guiding members are moved away from each other, the contacting member of the arms is configured to be moved away from each other and vice versa, and

- at least one threaded bar for moving the movable guiding members.

In the adjustable clamping mechanism, the coupling between the first and second arm and the guiding members may comprise first and second suspension arms re spectively, and the first and second suspension arms may be provided with a con tacting member configured to contact the surface of the workpiece.

More precisely the features defining an apparatus in accordance with the present invention are presented in claim 1 . The dependent claims present advantageous features and embodiments of the invention.

Exemplifying embodiments of the invention and their advantages are explained in greater detail below in the sense of example and with reference to accompanying drawings, where

Figures 1A-1C show schematically an embodiment of an apparatus of the in vention, and

Figures 2A-2C show schematically an alternative embodiment of an apparatus of the invention. Figures 1A-1C show schematically an embodiment of an apparatus 1 of the inven tion for working tubular or round-bar type pieces, such as for cutting pipe 4. Figure 1 A shows the apparatus 1 with the pipe 4 as a perspective view and Figures 1 B and 1C shows the apparatus 1 and the pipe 4 as cross-sectional views from opposite directions for better illustration of the second adjustment means.

The apparatus 1 comprises a tool unit 3 comprising a rotary machining blade 31 , such as circular saw, for machining the pipe 4. In the embodiment the apparatus 1 is designed as a hand tool.

The apparatus 1 also comprises a clamping mechanism 2, which is adapted to be fastened or grip to pipe 4 to be machined rotatably therearound. Rotation occurs in such a way that the apparatus 1 essentially retains its position in the axial direction of the pipe 4. The clamping mechanism 2 or the apparatus 1 comprises advanta geously contacting member, which is in this embodiment implemented by wheels 21 , 22, 23 and 24. Alternatively the wheels 21-24 may be replaced with other suita ble means, such as with a slide, for example. The wheels 21-24 are advantageously mounted with bearings in such a way that, when pressed against the pipe’s 4 exter nal surface, the clamping mechanism 2 can be rotated in a plane essentially per pendicular to the center axis of the pipe 4 or, respectively, the pipe 4 can be rotated relative to the clamping mechanism 2.

The clamping mechanism 2 comprises a frame element 6, and first and second arms 7, 8 extending therefrom, said arms being articulated at one end thereof to the frame element 6 of the clamping mechanism 2 and the free end of each arm 7, 8 is fitted with the wheel 21 , 22. On the first and second arm 7, 8 is also connected first and second suspension arm 9, 10, which suspension arms are articulated at one end thereof to the first and second arm respectively and the free end of each suspension arm 9, 10 is fitted with the wheel 23, 24.

The clamping mechanism 2 also comprises means for adjusting the clamping mech anism for different diameter tubes 4, which means comprise a turnable knob 11 . By turning the turnable knob 11 , a threaded rod 25 is turned, which moves guide mem bers 26 and 27 along the threaded rod 25 at opposite directions. The guide mem bers 26 and 27 are connected to the area of the free ends of the suspensions arms 9 and 10 respectively, so the movement of guide members 26 and 27 cause the change of the placement of the wheels 21-24 and thus the adjustment of the contact points of the clamping mechanism 2 to be suitable for different diameters of the workpieces to be clamped. The wheels 23 and 24 can alternatively be located in the frame element 6, or eliminated completely, wherein surface of the frame element 6 provides a third contact point in addition to the two provided by wheels 21 and 22.

Examples of these kinds of adjustment systems are more closely described in pub lication WO 02/02271 or WO 2004/013623, for example.

The tool unit 3 is connected to the clamping mechanism 2 with first adjustment means, which in this embodiment are embodied with a pivoting connection via an axle 5 between the tool unit and clamping mechanism. This pivoting connection al lows the displacement of the tool unit 3 together with rotary blade 31 relative to the clamping mechanism 2 towards and away from the pipe 4. The tool unit 3 has its blade 31 adapted advantageously to operate from outside a common rolling path of the wheels 21-24. The axle 5 is advantageously parallel to the axis of rotation of the rotary blade 31 .

The apparatus 1 also comprises a second adjustment means for adjusting the ex treme position for the displacement of the tool unit 3 and thus its rotary blade 31 rotary blade towards the workpiece. These second adjustment means are in this embodiment formed from a knob 12 fixed on a threaded member 13 for turning the threaded member, which threaded member is connected rotatably on the frame of the tool unit 3, a locking part 14 in threaded connection with the threaded member 13, and a locking surface 15 with a lock hole 16.

When moving the tool unit 3 and its rotary blade towards the pipe 4 clamped with clamping mechanism 2, the locking part 14 moves along the locking surface 15 until it reaches the lock hole 16. When the locking part 14 reaches the lock hole 16, its spring tensioned lock pin 17 drops into the lock hole thus restricting further move ment of the tool unit 3 toward the pipe.

For releasing the thus obtained locking, the lock pin 17 is raised from the lock hole by pulling release button 18 outwards and moving the tool unit 3 away from the pipe 4. Now, when the release button 18 is released the lock pin 17 presses against the locking surface 15 along which it can slide with the exception of the lock hole 16.

For adjusting the extreme position of tool unit 3 towards the pipe 4, the threaded member 12 is turned with the knob 11 , which moves the locking part 13 along the threaded portion of the threaded member 12 in relation to the tool unit 3, thus ad justing the extreme position. In figures 2A-2C is schematically shown an alternative embodiment of an apparatus T of the invention for working tubular or round-bar type pieces, such as for cutting pipe 4. Figure 2A shows the apparatus T with the pipe 4 as a perspective view, figure 2B shows the apparatus 1 ’ and pipe 4 as a side view, and figure 2C shows the apparatus 1 ’ and the pipe 4 as cross-sectional side view.

In this embodiment the tool unit 3’ with its rotary blade 31 ’ is connected to a clamping mechanism 2 which corresponds to the one discussed in relation to the embodiment of figures 1A-1 B.

Similarly than with the embodiment of figures 1A-1 B, the tool unit 3‘ is connected to the clamping mechanism 2 with first adjustment means, which are embodied with a pivoting connection via an axle 5 between the tool unit and clamping mechanism. This pivoting connection allows the displacement of the tool unit 3’ together with rotary blade 3T relative to the clamping mechanism 2 towards and away from the pipe 4. The tool unit 3’ has its blade 3T adapted advantageously to operate from outside a common rolling path of the wheels of the clamping mechanism 2. The axle 5 is advantageously parallel to the axis of rotation of the rotary blade 31 ’.

In this embodiment the second adjusting means comprise a plate member 41 , which is at one of its edge connected pivotably to the axle 5. On the opposite edge of the plate member 41 in relation to the axle 5 is arranged a manually rotatable disc 42, which disc 42 is rotatable in relation to the plate member 41 and which disc has a threaded center hole. In the outer surface of the clamping arrangement 2 is pivotally attached a threaded member 43 that extends upwards from the surface of the clamping arrangement. The disc 42 is in threaded connection with the threaded member 43 via the threaded center hole. Thus, when the disc 42 is manually rotated, the disc moves along the threaded portion of the threaded member 43, and raises and loves the edge of the plate member 41 accordingly.

When the tool unit 3’ is moved toward the pipe 4, this movement is stopped by the plate member 41 , so by adjusting the position of the plate member 41 in relation to the clamping mechanism 2, also the extreme position of tool unit 3’ and its rotary blade 3T is adjusted accordingly.

The specific exemplifying embodiments of the invention shown in figures and dis cussed above should not be construed as limiting. A person skilled in the art can amend and modify the embodiments described in many evident ways within the scope of the attached claims. Thus, the invention is not limited merely to the em bodiments described above.