Straightening device for a car body
BACKGROUND OF THE INVENTION 
     The invention relates to a straightening device for a car body. 
     Straightening devices for a car body are known in prior art, in which a vehicle is driven onto driving plates and in which the vehicle is fixed to a straightening table from so-called sill fasteners. In this way, the vehicle can be firmly fixed to a working stand, by means of which the vehicle can be lifted to the desired height and repair position. Separate straightening units and straightening heads can be mounted on the straightening table, and their joining to the beams of the straightening table has in the solutions of prior art been performed by leading a beam of a rectangular cross-section inside a beam structure of the straightening table, which beam structure has a corresponding form but dimensions deviating therefrom, whereby a telescopic structure is obtained. This telescopically joined structure is locked by leading a bolt both through an outer beam structure and a beam structure located more inside relative thereto. Since the innermost and the outermost beam must have a clearance relative to each other, the joint becomes flexible and it does not offer the best possibilities of performing a demanding and dimensionally accurate straightening work. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     The object of the invention is therefore to find an improvement on the joining problem, and it has been realized in the invention that it is advantageous to form the telescopic joint into a rigid form meeting the straightness requirements by forming a wedge coupling between an inner beam section and a beam section arranged more outside relative thereto. 
     The inventive straightening device for a car body is mainly characterized in that the equipment comprises a straightening unit joined to a straightening table, to its beam, which unit comprises a tool connected thereto or connectable thereto, by means of which a force can be concentrated on the object to be straightened, whereby the joint between the above-mentioned straightening unit and the straightening table is realized by leading a beam connected to the straightening unit inside the beam of the straightening table, and that the equipment comprises in connection with the straightening unit such a beam structure that at least the second beam section can be moved relative to the first beam section, whereby said sections comprise a surface diagonal relative to the center axis of the beam structure, and that the equipment comprises a power unit, by means of which the upper surface of the movable beam is brought into contact with the inner surface of the beam structure of the straightening table, whereby the upper surface of the beam structure aligns the straightening unit in the same horizontal direction as the straightening table and whereby the beam is by means of the power unit wedged relative to the beam section cooperative relative thereto, when the surfaces of the beam sections, which surfaces are cooperative relative to each other and diagonal relative to the center axis, are pressed against each other and kept together, as the actuator ensures a friction joint. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is next described with reference to certain preferred embodiments of the invention shown in the figures of the accompanying drawings, to which the invention is not intended solely to be limited. 
     FIG. 1 shows as a side view a straightening device for a car body, and also a straightening unit joined to the straightening table of the straightening device, the fixing of which unit is realized in the inventive manner. 
     FIG. 2A shows the joint structure of FIG. 1 as a side and cross-sectional view. 
     FIG. 2B illustrates the joining solution of FIG. 2A. 
     FIG. 2C shows the joint structure provided with two wedge pieces. 
     FIG. 3 shows another embodiment of the inventive joint structure provided with rollers. 
     FIG. 4 shows the use of the inventive joint structure, when a straightening head is joined to a separate straightening unit of the straightening table. 
     FIG. 5A shows the straightening unit shown in the device solution of FIG. 4 before the parts of the straightening unit are joined together. 
     FIG. 5B shows the device solution of FIG. 5A when assembled. 
     FIG. 5C shows a section I--I of FIG. 5B. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows a straightening device 10 for a car body according to the invention comprising a straightening table 11 and therein sill fasteners 13, to which the car can be fixed. By means of a lifting device 12, the vehicle P can be lifted above the straightening table 11 to the desired repair height. According to the figure, a straightening unit 14 is joined to the straightening table 11 and it comprises tools 15, e.g. drawing chains. The tool 15 on a straightening arm 14a of the straightening unit 14 can be turned by means of an actuator 14b such that the tool 15 concentrates a force to the object to be straightened in the vehicle. 
     According to FIG. 2A, the straightening unit 14 comprises on a straightening arm 14c an extension beam 16, which can be transferred inside a beam structure 11a of the straightening table 11. The beam 16 comprises a first beam section 17, which can be moved relative to a second beam section 18 with an actuator 19. A surface A 1  of the beam section diagonal relative to the center axis X of the beam is in the same manner diagonal as a surface A 2  of the beam 18, and when the beam section 17 is thus moved with the actuator 19, e.g. a screw 20, relative to the beam section 18 in the direction of an arrow L 1 , the beam section 17 is lifted into a position, in which an upper surface 17a of the beam section 17 comes into contact with an inner surface 11a 1  of the beam 11a of the straightening table. 
     According to the figure, the actuator 19 is a screw 20, which comprises at its end threads 21, which connect to threads 24 of an opening 23 of a cross-plate 22 of the movable wedge piece 17. In the straightening occurrence, a head part 20a of the screw 20 presses against a cross-plate 24. A through opening 25 of the cross-plate 24 is so large relative to the perimeter of the screw 20 that as the section 17 moves relative to the section 18, a change in the height position of said parts becomes possible, and at the same time, the screw 20 can turn relative to the center axis X. Thus, the upper surface 17a of the wedge piece 17 can be brought into contact with the inner surface 11a 1  of the beam 11a of the straightening table by turning the screw. 
     FIG. 2B illustrates the joint structure of FIG. 2A between the straightening unit and the straightening table 11. By means of the joint structure, the part to be joined to the straightening table can be brought into an exact desired position relative to the straightening table. The beam to be joined can be brought in the same horizontal direction as the straightening table. 
     FIG. 2C shows an embodiment, in which two wedge pieces 17&#39; and 17&#34; are moved with the same screw 20. Otherwise, the construction accurately corresponds to the constructions of FIG. 2A and 2B. By turning the screw device 20, the upper surfaces of the movable wedge pieces 17&#39; and 17&#34; are brought simultaneously into contact with the inner surface 11a 1  of the beam 11a of the straightening table 11. 
     FIG. 3 shows an embodiment corresponding to FIG. 2 except that an extension 27 to be joined to the straightening table 11, to its beam 11a, comprises at its end beam section 27a rollers 28, which guide the beam 27 relative to the beam 11a. In this way, the beam 27 can be aligned, guided by the rollers 28, into an accurate desired position relative to the beam 11a and locked in any position relative to said beam by means of the inventive arrangement. The wedge piece 17 can be moved against the counter wedge piece 18, when the surfaces A 1  and A 2  of the wedge pieces are in the same inclination angle as the center axis X of the beam. In the embodiments of FIGS. 2A-3, the actuator 19 can be a screw device, or the actuator 19 can be e.g. a double-acting pneumatic or hydraulic cylinder. The actuator 19 can also be e.g. a bar, the movement of which in the direction of the center axis X is achieved by an eccentric mechanism or by using e.g. gear wheels. 
     FIG. 4 shows a straightening unit 30 of the straightening table 11 joined to the straightening table 11, to which unit is joined by means of the inventive wedge structure a straightening head 31. 
     FIG. 5A shows axonometrically the straightening unit 30 of FIG. 4, when the parts functional relative to each other are separated. The straightening unit comprises a bed frame 32 and therein wheels 33, on which the frame can be transferred to the connection of the straightening table 11. The bed frame 32 further comprises a locking device 34, whose toothing 35 can be brought into a countertoothing 37 of the turnable frame part 36. The rotatable frame part 36 can be turned around a geometric axis, as a shaft 38 rotates in a shaft opening D of the bed frame 32. 
     FIG. 5B shows the separated parts of FIG. 5A when assembled. The rotatable frame part 36 can be turned into the desired straightening position and locked into the desired position, as the locking device 34 and the toothing 35 can be brought into the countertoothing 38, turnable by 180°, of the rotatable frame part, on the countertoothing plate 38. According to the figure, the rotatable frame part 36 comprises the movable wedge piece 17 and the wedge piece 18, which is in a fixed position relative thereto, the surfaces A 1  and A 2  of which pieces sliding relative to each other are diagonal with respect to the center axis of the beam formed by the above-mentioned parts. In the tightening occurrence, the part 17 can thus be lifted onto the beam section 31 to be joined thereto. 
     FIG. 5C shows the device solution of FIG. 5B as a section I--I of FIG. 5B. The screw 20 is led through the shaft 38.