APPARATUS AND SYSTEM FOR SECURING A CUTTING DEVICE TECHNICAL FIELD The invention relates to an apparatus arranged to secure a portable, hand-operated machine, having a circular cutting wheel or saw blade which is rotatable about a centre of rotation. The portable machine can comprise a double-armed holder with a rear arm which, at its free, rear end, is connected to the machine at a first hinge, rotatable about a first axis of rotation parallel to the axis of rotation of the cutting wheel or the saw blade, and, at the other end, is connected rotatably, by means of a toggle joint, to a front arm which in turn is connected rotatably, at its front, free end, to a securing device about a second axis of rotation at a second hinge. The securing apparatus is arranged for anchoring the holder and the machine onto the object which is to be cut or sawn, for the purpose of ensuring that the machine with the cutting wheel or the saw blade will be able to be displaced relative to the said object at right angles to the axis of rotation during turning of the arms at the said first and second hinges and at the said toggle joint.

BACKGROUND OF THE INVENTION

Apparatuses of the type described above are used, inter alia, in order to cut a railroad rail at right angles to the longitudinal direction of the rail. The securing device in this case consists of a vice which is mounted on the rail.

A known securing device is shown in US 5 545 079, in which a machine is clamped onto the object which is to be cut by means of a securing device in the form of a vice actuated by a manually actuated screw. The vice comprises a pair of parallel jaws with U-shaped openings having substantially the same shape as the rail onto which it is clamped. The vice is placed over the rail at right angles thereof and the screw is tightened until the securing device is clamped to the rail.

One disadvantage with this design is that it uses a pointed screw in order to attach to the rail that is to be cut. The screw leaves an imprint in the rail, which imprint that may act as a crack-initiation. Furthermore, the mounting of the attachment requires prior knowledge of its function. A non-experienced user may mount the attachment incorrectly, which may lead to the attachment coming loose during the cut. Also, in case of a worn rail problems may arise if the U-shaped openings of the jaws do not match the profile of the rail, making it difficult, if not impossible to use the known attachment.

The object of the invention is to provide an improved apparatus for securing a portable, hand-operated machine for cutting elongated profiled objects that solves the above problems.

INVENTION

The above problems have been solved by an apparatus and a system as claimed in the appended claims.

Apparatuses of the type described above are used, inter alia, in order to cut elongated profiled objects such as a railroad rail at right angles to the longitudinal direction of the elongated profiled object. The object is preferably, but not necessarily, an elongated profile with a substantially I- or T-shaped cross-section, where the apparatus is arranged to be clamped onto the enlarged portion thereof.

According to a preferred embodiment, the invention relates to an apparatus arranged to secure a portable cutting machine on an elongated railshaped profiled object, having a rail head with side portions and lower edges, said apparatus comprising a base adapted to be disposed on an upper surface of the profiled object and at least one arm mounted pivotable an arm pivot axis of the base at right angles to the main extension of said object; the base comprising two parallel, spaced plates with an opening for receiving the object; each plate comprising a central, first contact surface arranged to contact the upper surface of the object; and a second inwardly angled contact surface extending from a first end of the plates towards a corresponding side surface of the object, and arranged to contact a first lower edge of the rail head.

According to the invention the base further comprises a rocker arm having a first end, a central portion and a second end. The rocker arm is mounted pivotable about a first axis at right angles to the parallel plates between a second end of each plate, which first pivot axis is arranged through the central portion of the rocker arm.

The first end of said rocker arm comprising a third contact surface opposed to the respective second contact surfaces and extending towards a corresponding opposed side surface of the object, wherein the third contact surface of the rocker arm is arranged to be displaced towards a second lower edge of the rail head to clamp the profiled object, the clamping forces towards the lower edges are directed in a combined both lateral and vertical direction; When the apparatus is clamped to the object, each of the second and third contact surfaces are angled inwardly relative to a plane through the object in its main extension and at right angles to the first contact surfaces.

A clamping device is provided for actuating the rocker arm, where one end of the clamping device is mounted pivotable about a second axis at right angles to the parallel plates between their first and second ends. The second end of the rocker arm is journalled relative to a pivot on the clamping device, which pivot is located on a third axis parallel to and remote from the second axis.

The second end of the rocker arm is releasably mounted to the pivot on the clamping device. This can be achieved, for instance, by providing a semi-circular recess in the second end of the rocker arm facing the pivot. The pivot on the clamping device can be a cylindrical section that can be placed in the recess. According to one example, the clamping device can be provided with one pivot on either side, arranged to cooperate with a pair of recesses located on a forked portion of the second end of the rocker arm, which forked portion can extend on both sides of the clamping device. An advantage of this arrangement is that the clamping device only needs to be released a distance corresponding to the depth of the recess in order to release the apparatus from the object. When the pivot(-s) on the clamping device clears the recess(-s) it can be swung aside, allowing the rocker arm to be rotated to clear the object as the apparatus is removed. The displacement of the clamping device is achieved by mounting it to an attachment that is pivotable about the second axis. The end of the clamping device proximate the second axis comprises an actuator arranged to displace the rocker arm pivot relative to the second axis, thereby forcing the third contact surface at the first end of said rocker arm into contact with the object. The actuator can comprise a screw, which when rotated is arranged to displace the second end of the rocker arm relative to the second axis and the attachment. The screw can be arranged to cooperate with a tubular, internally threaded member comprising the pivot for the second end of the rocker arm. When the second end of the rocker arm is in contact with the pivot on the tubular member of the clamping device, rotation of the screw causes a relative displacement of the tubular member along the screw.

Alternatively, the actuator can comprise a piston-cylinder arrangement, which can be hydraulically or pneumatically actuated. In this case, the hydraulic cylinder can comprise the pivot or pivots for the second end of the rocker arm. The above-mentioned at least one arm has a free end, remote from the plates that provides an attachment point for the cutting machine. According to a further example, said arm and the clamping device are both mounted to and pivotable about the second axis. The second axis is located adjacent the first contact surface at a distance, measured at right angles from said surface, not greater than the distance between the first and third axes. This arrangement is used in order to minimize the effect of any torque induced to the clamped apparatus during displacement of the cutting machine relative to the object.

The invention further relates to a system using a securing device in the form of the above apparatus. According to the invention, the system comprises a plurality of separately usable and interchangeable components for cutting, sawing or slicing through objects, the system comprises a first component with a cutting wheel having a central drive shaft, at least one second component with a circular saw blade with a centerless driving, a holder and a securing device which is common to both the first and second components. The holder has a rear arm and a front arm, the rear arm having a free, rear end that can be connected to either component at a first hinge. A first spindle having a first extension piece is arranged at said first hinge. The rear arm is rotatable about a first axis of rotation parallel to the center of rotation of the cutting wheel or the circular saw blade, respectively. The rear arm also has a front end rotatably connected, by means of a toggle joint, to a rear end of said front arm. The front arm has a front, free end rotatably connected about a second axis of rotation at a second hinge for anchoring the holder and, thus, the respective component, on the object which is to be cut or sawn. When clamped in position, the first component with the cutting wheel or the second component with the saw blade is capable of being displaced relative to the said object at right angles to the first axis of rotation during turning of the arms at the said first and second hinges and at the said toggle joint. The centerline of the said first axis of rotation intersects a plane of rotation of the cutting wheel or the circular saw blade, respectively, at a point between the center of rotation of the cutting wheel or saw blade and a periphery of the cutting wheel or saw blade. At least two separately usable securing devices, which are exchangeable with one another, can be provided. Each securing device has at least one spindle attachment which can accommodate a second extension piece on a second spindle arranged at the said second hinge at the front end of the front arm of the holder, which second extension piece extends outwards from said second spindle in an opposite direction compared to the first extension piece, of the first spindle at the first hinge.

One object of the system according to the invention is to provide a system where the arms of the holder have a comparatively smaller relative length in relation to the diameter of the cutting wheel. In accordance with a first aspect of the invention, this is achieved by the fact that the centre line of the said first axis of rotation intersects, in its continuation, the cutting wheel, the saw blade or the space possibly present inside the saw blade, if the latter is annular, at a point between the centre of rotation of the cutting wheel or saw blade and the periphery. In the present invention, the requirement for optional anchoring of the extension piece of the spindle from one or other direction in the machine is also satisfied. This object is achieved by the fact that the attachments for the spindle are arranged in the machine on both sides of the plane of the cutting wheel or the circular saw blade, in which case the spindle attachments can be arranged opposite one another in such a way that their centre lines coincide, or, alternatively, are arranged on both sides of the cutting wheel, not opposite one another, but instead offset, so that their centre lines do not coincide, but are parallel to each other, which in certain cases can be an advantage.

Securing devices have also been developed within the context of the invention, including a securing device for mounting the holder, in conjunction with the sawing of long cuts, for example, in a wall. For instance, the device according to the invention can be clamped to the end of an elongated object forming a fixture, whereby the holder allows the cutting machine to be displaced from one end position, past the fixture to a second end position.

Further characteristics and features of, and advantages deriving from the invention are indicated in the attached patent claims and from the description which follows. FIGURES

In the following text, the invention will be described in detail with reference to the attached drawings. These schematic drawings are used for illustration only and do not in any way limit the scope of the invention. In the drawings:

Figure 1 shows a perspective view of an apparatus according to the invention on a cutting machine;

Figure 2 shows a plan view of a holder which, in a slightly modified embodiment (straight), is included in the apparatus according to Figure 1 ;

Figure 3 shows a side view of a holder-fastening yoke;

Figure 4 shows a view from above of the same holder-fastening yoke, a pair of spindle attachments included in the yoke being shown in cross-section;

Figure 4A shows a view in the direction of the arrow A in Figure 4; Figure 5 shows how a cutting machine with an apparatus according to the invention can be carried;

Figure 6 shows a schematic side view of a securing device according to the invention; and

Figure 7 shows a schematic perspective view of the securing device in Figure 6 attached to arms for supporting a cutting device.

DETAILED DESCRIPTION

First, with reference to Figures 1 -5, a cutting machine driven by a combustion motor is designated generally by the reference 1 . A cutting arm 2 is arranged on the cutting machine. In the cutting arm there is a drive chain or drive belt 3, which drives a cutting wheel 4 via a central shaft (not shown) about a centre of rotation 5. A holder-fastening yoke 6 is mounted on the cutting arm 2, and a rotatable holder 9 is fastened in a spindle attachment 7. A second spindle attachment is designated by 8. The holder 9 is in turn rotatably secured on a rail 1 1 with the aid of a securing device 10 which consists, in a known manner, of a screw vice.

The holder-fastening yoke 6, FIGS. 3 and 4, has a longer branch 13 on the right-hand side of the cutting wheel 4, a shorter branch 14 on the left-hand side of the cutting wheel, and a rib 15 behind the cutting wheel 4, which rib 15 connects the two branches 13 and 14 to one another. Furthermore, a securing plate 16 is arranged under the longer branch 13 and covers the front part of the cutting arm 2 and is joined to the latter.

According to the embodiment, the two spindle attachments 7, 8 are coaxial, that is to say are arranged with a common axis opposite one another on both sides of the cutting wheel 4 and at a level above the cutting arm 2. The spindle attachments 7, 8 are furthermore arranged so far forward that their common centre line 18 intersects the cutting wheel 4 at a point behind the centre of rotation 5, between the said centre of rotation and the periphery of the cutting wheel 4. The holder 9 comprises two arms, namely a rear arm 20 and a front arm 21 , which are rotatably connected to each other by means of a toggle joint 22. The free end of the rear arm 20 comprises a bearing housing 27, as shown in Figure 2, in which a shaft or spindle 19 is mounted, axially immovable. An extension piece 28 on the spindle 19 extends in the direction towards the machine. This extension piece 28 consists of a threaded point 30, a cylindrical section 32 and a conical section 29 nearest the bearing housing 27. On the other side of the bearing housing 27, the spindle 19 is provided with a handle 31 , by means of which the spindle 19 can be turned in the bearing housing 27 when the extension piece 28 of the spindle is to be anchored in either of the spindle attachments 7, 8. At the front end of the front arm 21 of the holder 9 there is a bearing housing 26, and a shaft 33 is rotatably movable in this bearing housing 26. The shaft 33 is secured, at both its ends, in a securing device 10 which can be secured on the rail 1 1 with the aid of a screw 25. A helical spring 24 extends between the securing device 101 and a pin 23 on the toggle joint 22.

The two spindle attachments 7, 8 are designed identically in order to be able to receive and anchor the projecting extension piece 28 of the spindle 19, and for this reason they have, furthest inside, an internally threaded hole 34 in a steel sleeve 38 for the threaded end- journal 30, a cylindrical section 35 for the cylindrical projecting section 32 of the spindle extension piece, and a conical mouth section 36 for the conical section 29 adjacent to the bearing housing 27. When mounting the holder 9 onto the machine 1 , the threaded end 30 on the spindle extension piece 28 is screwed into the threaded hole 34 in one of the spindle attachments 7, 8 with the aid of the handle 31 until the conical section 29 on the spindle extension piece 28 engages with the conical mouth section 36 in one of the spindle attachments 7, 8. The rear arm 20 of the holder can then be turned in the bearing housing 27 about the spindle 19 situated in the bearing housing and anchored in the machine, the centre line of which spindle 19 coincides with the centre line 18 intersecting the cutting wheel 4 above the cutting arm 2 and, thus, also above the drive belt or equivalent 3, that is to say comparatively high up on the machine. This means that the machine 1 can be carried by the handle, with the holder 9 mounted in the machine, without the holder 9 or its securing device 10 dragging along the ground, at least not when the securing device 10 consists of a screw vice or equivalent, with comparatively small dimensions. This is illustrated in Figure 5. By means of the positioning of the spindle attachments 7, 8, the integrated unit also becomes well-balanced, which also makes it easier to carry, as does the fact that the holder 9 can be made considerably lighter than known equivalent constructions.

The attachment 8 is slit in Figure 4A, which permits a possibility of axial adjustment of the sleeve 38. In this way it is possible to compensate for different thicknesses of different cutting wheels 4 or saw blades when it is intended, for instance, to cut an object, for example a railroad rail, and to do half the cut from each side in order to compensate largely for intolerances in the construction, and where it is desired that the saw cuts from both directions should meet and coincide with great precision.

Figure 5 shows how a cutting machine with an apparatus according to the invention can be carried. In this carrying position the holder 9 will hang straight down and the helical spring 24 extending between the securing device 10 and a pin 23 on the toggle joint will hold the securing device 10 in the position indicated. Figures 6 and 7 show a securing device connected to a cutting machine and a holder 9 similar to the ones shown in Figures 1 -5. Figure 6 shows a schematic side view of a securing device arranged to secure a portable cutting machine on an elongated profiled object 11 (indicated in dashed lines), in this case a railway rail. The securing device comprises a base 100 adapted to be disposed on an upper surface of the profiled object 1 1 and an arm 101 (see Figure 1 ; "arm 21 ") pivotably mounted to the base 100 at right angles to the main extension of the object 1 1 . The base comprises two parallel, spaced plates 102, 102' with an opening 104 for receiving the object 1 1 . Each plate 102, 102' comprises a central, first contact surface 105, 105' arranged to contact the upper surface of the object 1 1 and a second inwardly angled contact surface 106, 106' extending from a first end 108, 108' of the respective plate towards a corresponding side surface 1 1 a of the object 1 1 .

In this example the first end 108, 108' of said plates each form a relatively stationary jaw that partially embraces the object 1 1 , in this case a rail head. The jaws extend transversely across the object 1 1 and comprise a side portions surrounding one side 1 1 a of the rail head 1 1. The respective second inwardly angled contact surfaces 106, 106' extend from below into contact with a first lower edge 1 1 c of the rail head 1 1 .

The base 100 further comprises a rocker arm 1 10 having a first end 1 11 and a second end 1 12, connected by a central portion 1 13. The rocker arm is mounted pivotable about a first axis A1 at right angles to the parallel plates 102, 102' between a second end 109, 109' of each plate, which first pivot axis A1 is arranged through the central portion 1 13 of the rocker arm1 10. The first end 11 1 of the rocker arm 110 comprises a third contact surface 1 14 opposed to the respective second contact surfaces 106, 106' on the respective plate 102, 102', which third contact surface 1 14 extends towards a corresponding opposed side surface 1 1 b of the object 1 1 . The third contact surface 114 of the rocker arm 1 10 is arranged to be displaced towards the opposed second contact surfaces 106, 106' to clamp the object 1 1 .

In this example the rocker arm 1 10 forms a movable clamping jaw with a third clamping surface 1 14 intended to extend from below into contact with a second lower edge 1 1 d of the rail head 1 1 , opposite the first lower edge 1 1 c.

A clamping device 1 15 is provided for actuating the rocker arm 1 10, where a first end 1 16 of the clamping device is mounted pivotable about a second axis A2 at right angles to the parallel plates 102, 102' between their first and second ends 108, 108' and 109, 109', respectively. The second end 1 12 of the rocker arm 110 is journalled about a pivot 107 on the clamping device 1 15, which pivot 107 is located on a third axis A3 parallel to and remote from the second axis A2. In this example, the clamping movement of the movable clamping jaw 1 10 in relation to the rail 1 1 is applied by the clamping device 1 15. At this point the central, first contact surface 105, 105' is in contact with the upper surface of the profiled object 1 1 and the second inwardly angled contact surface 106, 106' can be moved into contact with the first lower edge 1 1 c of the rail head. The rocker arm 1 10 with its third clamping surface 1 14 is pivoted by the clamping device 1 15 into contact with the second lower edge 1 1 d of the rail head. It should be noted that the clamping forces towards the lower edges 1 1 c, 1 1 d are directed in a combined both lateral and vertical direction. Each of these forces will act in a direction of appr. 45 degrees (30-60 degrees) towards the first contact surface. Hereby the base is strongly centerred around the profiled object 1 1 . In this way the securing device is securely fixed and accurately located in a desired position at right angles to the intended cut. This arrangement also allows the securing device to adapt itself to objects such as rails with different rail head widths. Further it should be noted that the rocker arm 1 10 is arranged in between the two parallel plates 102, 102 ^' at a distance to the closest plate being more than 30%, and preferably more than 40%, and most preferably being 50%, of the total distance between the plates. So there are two contact points with the first lower edge 1 1 c and one contact point with the opposite second lower edge 1 1 d, being located halfway between the two other contact points, but opposite. This 3 point system creates a very strong self centerring action and a very stable position for the base 100. As indicated in Figure 6, the second end 1 12 of the rocker arm 1 10 is releasably mounted to the pivot 107 of the clamping device 1 15. A semi-circular recess 120 is provided in the second end 1 12 of the rocker arm facing the pivot. The pivot 107 on the clamping device 1 15 has a cylindrical section, so that it conforms to the shape of the recess 120. According to this example, the clamping device 1 15 is provided with one pivot 107 on either side, arranged to cooperate with a pair of recesses located on a forked portion of the second end of the rocker arm (see Figure 7), which forked portion can extend on both sides of the clamping device. For reasons of clarity, only one pivot is described in the text. An advantage of this arrangement is that the clamping device 1 15 only needs to be released a distance corresponding to the depth of the recess in order to release the apparatus from the object. When the pivot 107 on the clamping device clears the recess, the clamping device is pivoted upwards about the second axis A2. The rocker arm can then be swung aside, allowing it to be rotated to clear the object as the apparatus is removed.

The end of the clamping device 1 15 proximate the second axis A2 is mounted to an attachment 1 17 pivotable about the second axis A2. The clamping device 1 15 comprises an actuator arranged to displace the rocker arm pivot 107 relative to the second axis A2. The actuator shown in Figure 6 comprises a rotatable screw 1 19 arranged to displace the second end 1 12 of the rocker arm 1 10. This displacement forces the third contact surface 1 14 at the first end 1 1 1 of the rocker arm 1 10 into contact with the object 1 1 . The screw 1 19 is arranged in a tubular member 1 18 comprising the pivot 107 for the second end 1 12 of the rocker arm. The screw 1 19 is arranged to cooperate with the tubular, internally threaded member 1 18. When the second end 1 12 of the rocker arm 1 10 is in contact with the pivot 107 on the tubular member 1 18, rotation of the screw 1 19 causes a relative axial displacement of the tubular member 1 18 along the screw 1 19.

Alternatively, the actuator can comprise a piston-cylinder arrangement. In this case, the cylinder can comprise the pivot 107 for the second end 1 12 of the rocker arm 1 10.

The arm 101 and the clamping device 1 15 are pivotable about the second axis A2. The arm (101 ) has a free end that provides an attachment point, such as a toggle joint 22 (Figure 2), for the cutting machine (1 ). In this example, the arm 101 and the clamping device are both mounted to and pivotable about the second axis A2. The second axis A2 is located adjacent the first contact surface 105, 105' at a distance, measured at right angles from said surface, not greater than the distance X between the first and third axes A1 , A3 when the pivot 107 is located in the recess 120.

Figure 7 shows a schematic perspective view of the entire holder 9 securing device in Figure 6 attached to a rear arm 20 and a front arm 21 (see Figure 1 ) for supporting a cutting device. The front arm 21 corresponds to the arm 101 shown in Figure 6. The free end of the rear arm 20 comprises a bearing housing 27, as shown in Figures 1 and 2. A handle 31 is provided on one side of the bearing housing 27, which can be turned in the bearing housing 27 for attaching of detaching a cutting machine (not shown). The rear arm 20 and the front arm 21 are rotatably connected to each other by means of a toggle joint 22. The front arm 21 , 101 is pivotably mounted to the base 100 of the securing device. The base comprises two parallel, spaced plates 102, 102' which are separated by a first and a second spacer 131 , 132.

As indicated in Figure 6, the second end 1 12 of the rocker arm 1 10 is releasably mounted to the pivot 107 (one shown) on either side of the clamping device 1 15. According to this example, the clamping device 1 15 is provided with a tubular member 1 18 having one pivot 107 on either side of the tubular member 1 18 (see Figure 6), which pivots 107 are arranged to cooperate with a pair of recesses located on a forked portion of the second end 1 12 of the rocker arm (see Figure 7), which forked portion partially encircles both sides of the clamping device 1 15. The pivots 107 on the clamping device 1 15 have a cylindrical cross-section, so that they conform to the shape of the recesses 120. An advantage of this arrangement is that the clamping device 1 15 only needs to be released a distance corresponding to the depth of the recesses 120 in order to release the apparatus from the object. When the pivots 107 on the clamping device clear the recesses, the clamping device is pivoted upwards about the second axis A2. The rocker arm 1 10 can then be swung aside, allowing it to be rotated to clear the object as the apparatus is removed. For instance, if the depth of the recesses is selected to be equal to half the diameter of the pivots, then the securing device can be released after only a few turns of the screw 1 19.

In operation, a system comprising a cutting machine and a securing device as described above is held as indicated in Figure 5 and is lowered onto a rail to be cut at a set position. The first contact surface 105, 105' is placed in contact with the upper surface of the object 11 and the second inwardly angled contact surface 106, 106' is placed in contact with its corresponding side surface 1 1 a of the object 1 1 . If necessary, the securing device is displaced along the rail until the cutting machine is positioned correctly. The rocker arm 1 10 is then pivoted about the first axis A1 , moving its first end 1 1 1 towards its corresponding side surface 1 1 b of the rail, until the clamping device can be pivoted about the second axis A2 past the second end 1 12 of the rocker arm 1 10. The pivot 107 on the clamping device 115 is aligned with the recess 120 and the clamping device 1 15 is actuated to bring the pivot 107 into contact with the recess. Continued actuation of the clamping device 1 15 will force the first contact surface 1 14 into contact with the rail (see Figure 6; dash-dotted lines) and secure the system onto the rail. Once secured, the cutting machine is actuated to perform a cutting operation. Subsequently, the above steps are performed in reverse to release the system from the rail.

The invention should not be deemed to be limited to the embodiments described above, but rather a number of further variants and modifications are conceivable within the scope of the following patent claims.