VIBRATOR UNIT PREFERABLY FOR CONSTRUCTION WORKS

Abstract: Vibrator unit preferably for construction works such as rock scaling having a tool (17) with an active functional portion (21) together with a vibrator unit (25) connected with the tool for the production of vibrations in the functional portion. The unit comprises a pedestal arrangement (1, 2) which is arranged to support the tool in the vibrator unit. The pedestal arrangement (1, 2) is so arranged that by means of a shaft device (16) it supports the tool (17) in swivel fashion on a rotating shaft which is located at a distance from the functional portion (21) and to support the vibrator unit (25) in such a way that an active impact portion (27) of the latter is in contact with the tool at a distance from the said axis of rotation.

Description: Title: 7ibrator unit preferably for construction works Technical field: The invention relates to vibrator units in which a tool is arrange to bring about the machining of a surface by means of vibrations to wh the tool is subjected. It also relates preferably to tools which are intended for construction works, such as the machining of hard materia encountered in the construction work context, such as hard ground, road surfaces or rock and stone. As an example of work in this sphere we can mention the tearing up of road surfaces or "scaling" of rock walls. This involves machining of the surface during whichlcose piece of stone are broken away so that there is no risk that they will work themselvesloose and accidentally drop downwards. Background; In the case of rock scaling the method is previously known of arranging units which are supported by an arm on a mobile machine, e.g. an excavating machine adapted for this purpose. Such units operate in accordance with two main principles. One main principle is that a fixed, pointed tool known as a tearer is employed for scaling purposes, which pulled across the surface of the rock and takes theloose lumpβ with it or which is pressed by force into the cracks so that the lumps are broken away. In accordance with the second main principle a pointed tool is employed which is subjected to vibrations. This gives a better effect than with fixed tools, so that the work proceeds more rapidly. Even lumps which are seated relativel firmly can easily be broken away by introducing the vibrating tool into an adjacent crack. The present invention relates to the latter type of unit. The unit can also be employed for purposes other than rock ft- scaling, e.g. as mentioned by way of example, the breaking up of road surfaces, and also for the removal offhrnace linings and the removal of surface-ice. In order to impart the vibration to a tool of type specified a vibrator is required. On the market very effective vibrators are available and these are intended for rock drilling machines and hand- operated tools such as crow-bar units, chisel hammers and the like. 1 Such vibrators or impact units designed for operation with compressed air or hydraulic medium have been well tried and are used in large numbers, so that it is advantageous to be able to employ such units to the greatest extent possible instead of specially-constructed vibr However they possess certain features which make them difficult to em in machine-mounted units for heavier work such as rock scaling. This is because such impact units are so designed that they require a counter-pressure in order to start the impact movement, whilst in the case of machine-mounted rock scaling units a continuous impact movemen is required. Vibrators or impact hammers of the said type will not function without any counter-pressure. In spite of this character istic, which is disadvantageous in. the present context, it is most useful to be able to employ such -runits for the reasons specified abo However one more significant disadvantage is that impact units of thi type cannot be subjected to the severe stresses which are imposed on the tool on a machine-mounted rock scaling unit. The solution: The solution by means of which the unit in. accordance with the present invention obtains its advantages, is orientated towards a mounting of the vibrating tool. This is not mounted, as with con¬ ventional units, directly on the impact hammer which forms the vibrator unit, but instead by means of a is connected with the pedestal of the unit. AdvantagesJ The unit in accordance with the present invention has the advanta of being extremely robust, and the tool can be subjected to extremely high stresses without the actual vibrator unit being subjected to ris of damage. Furthermore by means of the present invention, as will be outlined later,- automatic control of the impact force and impact amplitude is obtained so that the mode of working adapts to the task involved. Brief description of drawings: The appended drawings illustrate an embodiment of the invention. Fig. 1 shows a perspective view of a unit in accordance with the invention; fig. 2 illustrates the unit applied to a working machine; fig. 3 illustrates in somewhat schematic form a section through the unit and fig. 4., 5 and 6 illustrate different forms of the tools suitable for the unit. Best mode of carrying out the invention: The invention will now be described mainly with reference to fig. 3 which shows a section through the unit. The unit comprises a pedestal 1 of box shape. This encloses a housing 2. By means of bearings 3 and 4. the housing 2 is rotable in the pedestal 1 and the rotation can take place by means of a motor 5 in the pedestal 1 which via a gear-box 6 can rotate the housing 2. The motor 5 is preferably a hydraulic motor. The pedestal 1 is in turn supported by a rotary mechanism 7 which in fig. 3 is illustrated clearly as a plate-8 combined with the pedesta 1 and a second plate 9 which is fastened to two bearing brackets 10 which via shafts 11 are combined with two stays 12. The plates 8 and " 9 are rotable in relation to each other and are combined with a rotary mechanism so that the pedestal 1 can be twisted around an axis which is at right-angles to the axis around which the housing 2 can be rotate The twisting mechanism is illustrated to some extent by fig. 1 and is here designated as 13- It comprises essentially a number of lever arms together with a hydraulic servo cylinder. By means of such an arrange¬ ment a rotation of about 170 can be obtained. This should be adequate for most purposes, but rotation through 3-60° can be obtained if the twisting mechanism is provided with a motor in a manner similar to the twisting mechanism for the housing 2. Usually the unit is mounted on a mobile machine which can move this, and this i3 done by means of the arms 12 and as a result of the various movements of these arms the unit can be displaced in different directio It can also be swivelled around an axis at right-angles to the plane of the paper in fig. 3. Fig. 2 illustrates an example of the mounting of the unit, and this diagram will be clarified later. From the housing 2 on a section which is located beyond the pedestal 1, two bearing brackets 15 proceed. A shaft 16 on which the actual tool 17 is rotably arranged extends through the bearing brackets. The tool 17 has an arm 18 with a hole 19 which is mounted on the shaft 4. ■ ^V R - - ■ - " A- From the arm 18 a circular tool portion 20 having an outer tip 21 projects some distance from the shaft 16, the tip representing the functional portion of the tool. This has to be brought into contact with the surface which is to be machined. Thus during rock seeing it must be passed across the surface of the rock wall and into cracks present therein. The arm 18 carries a stop surface 22 which is at some distance from the hole 19 * A compressed air or hydraulic-driven impact unit 25 comprising a head body 26 and an impact bar 27 is mounted in the housing. Inside the head body 26 there is a cylinder with a piston and a transmission mechanism for the medium so that the impact rod 27, which is linked with the piston, has imparted to it a reciprocating motion when the impact unit functions. By means of a stop surface 28 this movement can be imparted to the impact surface 22 and thus to the tool 1 . The housing 2 carries a support 29 for the tool 17 against which support the stop surface 22 can rest with the tool in an interior position. The impact unit 25 is supported ~bj he housing 2 by means of a sleeve 30. The unit 25 is supported by a compression spring 31 which rests against its head body 26 and is supported by the housing 2. As mentioned, the impact unit 11 is driven by compressed air and thus must be connected to a source of compressed air. This is achieve by e-ans of hoses, not shown, and an actuating valve is providedibr controlling the unit function. On the tool 5 there is a shaft 32 which is located at a distance from theaxis - of rotation 19 of the tool. A link 33 is attached to the shaft 32 and its far end carries a plate 3 which is held in posit by means of an adjusting screw 35. A compression spring 3 , which is supported by the housing 2 by means of a plate 37 through which links extend rests against the plate 34-« When the spring 3 is tensioned, it thus exerts a moment against the tool 17 so that the stop surface 22 of the latter is pressed against the stop surface 28 of the impac rod 27. The aim of the spring system illustrated is to maintain a positive contact between the vibrator unit 25 and the tool 17. This contact is achieved as a result of the oppositely-directed effect of the two springs 31 and 36. The spring 31 which carries the vibrator unit 25 at the same time protects this against excessively severe forces, because it can retract downwards until the surface 22 of its tool 17 rests against the fixed stop 29. Hence the vibrator unit 25 c-an slide in the sleeve 30. To cope with different .operating conditions it can be useful to have the facility for changing the spring pressure between the two portions. Fig. 3 - llustrates how the pressure from spring 36 against the tool 17 can be altered by means of the nut 35. A similar adjustment facility can also be provided at spring 31 by making its support in the housing 2 adjust¬ able. However such adjustment facilities are too difficult to operate if the pressure is to be changed during working, but are moresuitable for adjusting the springs to the correct pressure during assembly and in conjuction with servicing. Nevertheless it is possible to arrange several easily-operated mechanisms for changing over the spring pressure. For example the springs can be supported by servo-cylinders which can be adjusted in various position by means of hydraulic fluid. It is also possible to replace the mechanical springs illustrated by pneumatic springs, the spring force of which can be altered by varying the air pressure or by a hydraulic system having a hydraulic fluid/air accumulator of a known type. However the position of such modification facilities represents state of the art taking as a basis what has been said here. The previous description has been based mainly on fig. 3- However the unit described is also illustrated in fig. 1 in the form of a perspective view. The components described previously which are also visible in fig. 1 have been given the same notation numbers as in fig. 3» Because of the fact that fig. 3 is a schematised section, provided for the sake of clarity, whilst fig. 1 resembles more the practical embodiment, some of the details are not absolutely identical in both diagrams. Thuβ, as previously mentioned, the rotating mechani 13 is illustrated merely as two plates in fig. 3, whilst it is shown in more detailed form in fig. 1. Fig. 2 illustrates a practical application of the unit. Its main components previously described, the pedestal 1, the housing 2, the tool T;7 and the tool tip 21 are also illustrated in this diagram. However here the housing 1 is extended by a portion 40, the end of which is attached to the rotary unit 13, which in turn is mounted in b brackets 10 by means of shafts 11. The arms 12 indicated in fig. 3 here comprise partly an arm 1 to an arm system 42 supporting the tool appertaining to a truck 43. The second arm 12 comprises the piston rod to a servo cylinder 4 mounted on arm 1 by means of which the housing 1 can be swivelled in different directions. The dash-dotted lines in fig. 2 indicate how the unit can be moved into different positions. It can thus be raised and swivelled in a longitudinal plane through the machine by means of the system of arms 42. Furthermore the unit c-an be rotated around an axis which is located in this plane by means of the rotating mechanism 13» Apart from this the housing 2 can together with the tool 17, be rotated in the housing 1 and thus along shafts which, as a result of swivelling in the rotary mechanism 13, can be placed in various angular positions in relation to the said longitudinal plane. The machine 43 is provided with actuating devices for actuating the various movement devices on the unit and the vibrator unit. The application illustrated in fig. 2 is intended mainly for rock scaling. As a result of the said facilities for movement of the unit its tool tip 21 can ' be orientated towards any point within the range of the machine and at any angle in relation to the surface which is to be machined. By this means it is possible to obtain the best possible orientation or dealing with those portions of the rock which are to be brokenloose. This is very important, because by this means it is possible toobtain the desired result as rapidly as possible by utilising the cracks and weaknesses which are present in the rock. By means of the extension of the housing 1 the unit can be adapted to function high above the machine and the extension also provides a greater range towards the sides when swivelling the unit. Fig. 4-6 illustrate different tool shapes. In fig. 4 the tip of the tool is shown as a pyramid which corresponds with the design shown in the remaining diagrams. For certain operations the chisel shape shown in fig. 5 can be more suitable. Fig. 6 illustrates a spade-like shape which is particularly intended for dealing with π pot-holes α in road surfaces. Such holes occur as a result of uneven wear and when these are to be repaired the walls of the holes have to be prepared for the insertion of the new surfacing material. Thanks to the great mobility of the unit when using the tool as shown in fig. 6 a circular hole with cup shape can be obtained by vibrating the tool with simultan IsU H rotation of the latter. Obviously during such application the tool has to be directed downwards, as opposed to what i3 shown in fig. 2. With all embodiments the tool 17 is thus subjected to a spring force which tries to press it against the stop surface 28 of the impact rod 27. By this means the pneumatic impact unit 25 receives the requisite compression force and performs its impact movement. • These are imparted to the tool 17 which starts to swivel"around its axis 16. By this means the tip 21 performs a reciprocating movement which carries out the machiniiig work. During the work, when the tip can be pressed with great force against the surface by means of the supporting machine, considerable forces can be imposed on the impact unit. However thi3 has the facility for resilience downwards as a result of the mechanical or hydraulic springing. If furthermore a stop, such as the stop 29 in fig. 1, is provided for the swinging movement of the tool portion and the position of this stop is so adapted in relation to the spring force exercised against the impact unit that this can accommodate the forces prevailing .at maximum spring force when the tool portion impacts against the stop, any possible damage to the impact unit is prevented. During a tearing π , i.e. when during rock scaling the tool tip is pulled across the rock wall surface, the tool is thus able to rest against the stop and then functions as a fixed tool. Hence the work can alternate between chiseling between cracks and tearing without the unit needing to be changed over and without there being any risk of damage to the impact unit. With such embodiments mentioned, where the ■ spring force is adjustable, the force- by which the impact unit is pres against the tool portion can be adjusted to suit different working conditions. One effect αf the invention, which is p-articularly valuable during rock scaling work, is automatic adjustment of amplitude and impact forc If the tool meets reduced resistance, e.g. when the tool tip is breaki open a crack, the contact between the tool and the impact unit will not be so great, which results in a large impact amplitude. As a resultth performs a relatively large swinging movement around the axis 16. The direction of the swivelling movement can be adapted by means of the- geometry of the tool. The geometry illustrated in the diagrams has proved to be " advantageous for rock scaling. This relatively,large movement results in rapid breaking open of the crack and loosening and removal of the rock lumps present. If on the other hand a higher resistance should be encountered, e.g. when dealing with solid rock o the start of the breaking up of a small crack, a larger contact force prevails which results in a reduced amplitude. At the same time the force increases due to the vibrations having reducing amplitude. As a result of-the said circumstance a large impact amplitude is obtained at the tool tip with reduced resistance, which signifies rapid working The fact that at the same time the machin g force is reduced is not of any significance here, because this is of course adapted to suit the resistance. On the other hand with increased resistance, the requisite force is provided and the reduced amplitude does not impose any disadvantage, because with the increased resistance the tool tip does not have a larger freedom of movement. The arrangement in accordance with the invention has mainly been described as usedfor rock scaling. As has been indicated, the unit is also highly suitable for this purpose because of its considerable adjustment facilities and because-of theaid adaptation, to- orking resistance. In turn thiβ adaptation means that the performance of the tool is exploited to its maximum and it is adaptable to the nature of the work and no overloading of the impact unit can occur, -so that even work which involves a high static pressure, e.g. tearing of rock, can beexecuted and alternate with dynamic utilisation of the tool impact capacity without any changeover being required.

Claims: Patent claims: 1. Vibrator unit pre erably or construction works such as rock scaling with a tool (17) having an active machining section (21) together with a vibrator arrangement (25) connected to the tool for production of vibrations in the machining section, where the unit comprises a pedestal arrangement (1, 2) which is arranged to support the tool and the vibrator arrangement and which iβ preferably arranged to-be supported by a tool support (43) characterised in that the pedestal arrangement (1 , 2) is arranged by means of a shaft arrangement (16) to support the tool (17) in swivel fashion inan axis of rotation which is located at some distance from the machining portion (21) and to support the vibrator unit (25) in such a way that an active impact portion (27) of the latter is in contact with the tool at a distance from the said axis of rotation. 2. Vibrator unit as in patent claim 1, characterised in that the vibrator unit (25) in the pedestal arrangement (l, 2) is influenced • by a spring arrangement (31 ) in such a way that the active impact portion (27) is pressed against the tool (17) which in turn by means of a spring arrangement (36) is arranged to provide a counter-pressure against the active impact portion. 3. Vibrator unit as in patent claim 2, characterised in that an impac stop (29) on the pedestal arrangement (1 , 2) is provided for the tool (17), which i3 arranged to prevent the tool from swivelling in the direction towards the vibrator arrangement (25) by more than a restric amount, by which means the vibrator unit, thanks to the said spring .arrangement (31), can spring downwards so that the said increased forc are accommodated directly by the pedestal arrangement (1, 2) via the stop (29). 4. Vibrator unit in accordance with any of the preceeding patent claims characterised in that the pedestal arrangement (1, 2) comprises an outer portion (1 ) with a fixing device (10) by means of which the unit can be supported by the tool support (43) and that the said portion by means of a bearing arrangement (3, 4) supports a housing (2) which in turn supports the tool (17) in. conjunction with the vibrator unit (25) so that the tool can be rotated along an axis of rotation by the rotation of the housing (2) in this bearing arrangement (3, 4). 5. Vibrator" unit as in patent claim 4 characterised in that the outer portion (1) of the pedestal arrangement is combined with the fixing device (10) by means of a rotating mechanism (13) so that the pedestal arrangement can be rotated in relation to the fixing device in a plane which is essentially at right-angles to the axis of rotati of the housing (2) which supports the tool (17). 6. Vibrator unit as in patent claim 5 characterised in that the fixi device (10) is so supported by the tool support (43) that together wi the unit it can rotate around a third axis which is essentially at right-angles to the angle of ro ' tation of the rotating mechanism (13).

Inventors: MANNBRO ROLF, MANNBRO, ROLF
Applicants: MANNBRO ROLF, MANNBRO, ROLF
Application year: 1982
Main classification: E02F5
IPC codes: E02F5, E02F9, E21D9