EP0278231B1 - Device for working stone - Google Patents

Description

The invention relates to a stone processing device for stagnation of stones with a plurality of processing tools in a common height-adjustable tool holder in the form of a swing frame and a tool block attached to it, each tool held in a bore in the tool block being individually acted upon by an eccentric articulation of the tool holder in order to achieve this Machining the surface of a stone pushed underneath.

A device with the features of the preamble of claim 1 is already known from DE-A 2 301 653.

A well-known surface treatment for stones is faltering. For this purpose, certain tools known as stick chisels are used, which are used not only in manual operation, but also together with processing machines, usually one or more chisels being arranged in one device and being driven either mechanically, pneumatically or electrically. This surface treatment is not only used for natural stone products, but also for concrete stones, whereby the creation of natural stone-like surfaces is striven for, which has the character of a surface hand-worked by stonemasons.

Stone processing devices for processing stone surfaces with a large number of processing tools in a common height-adjustable tool holder have long been known from DE-C 5 043 and 60 817. A large number of processing tools are then arranged in a row next to one another and individually subjected to mechanical force. The stone surface to be machined is shifted horizontally under the machining tools. The stone surfaces processed with such devices have a regularly repeating structure since the tool holder cannot be moved horizontally.

For this reason, it is also known to mount a processing tool with one or more stick chisels horizontally displaceably on a portal construction and to move it transversely to the direction of transport of the stone to be processed during processing. Because of the vibration phenomena that cannot be suppressed during machining, only one machining tool with a single chisel can generally be attached to the portal construction mentioned. This makes processing large stone areas very time-consuming.

In order to process the surface of concrete blocks and in particular of concrete block paving in such a way that the impression of a natural stone made in manual stonemasonry is created, a processing device is to be created in which a large number of tools individually process the surface simultaneously in a random distribution.

• - daß am Schwingrahmen eine Vielzahl von Unwuchten gelagert ist;
• - daß der Schwingrahmen in einem horizontal verfahrbahren Querschlitten höhenverschiebbar gelagert ist;
• - daß der Werkzeugblock mit einer der vorgegebenen Rasterverteilung der Werkzeuge entsprechenden Vielzahl von senkrecht verlaufenden Bohrungen versehen ist, in welchen Schlagbolzen geführt und durch eine Druckfeder gegen das jeweilige lose in einer Werkzeugplatte gehalterte Werkzeug vorgespannt sind;
• - daß in Bohrungen der Werkzeugplatte als Werkzeuge Bearbeitungsstifte oder Stahlnägel eingesetzt sind, deren Köpfe in senkrechten Erweiterungen der Bohrungen liegen und
• - daß die Werkzeuge durch die von den Unwuchten in Schwingung versetzen Schlagbolzen beaufschlagt sind.

According to the invention, this object is achieved by

• - That a large number of imbalances is mounted on the swing frame;
• - That the swing frame is vertically displaceable in a horizontally movable cross slide;
• - That the tool block is provided with a plurality of perpendicular holes corresponding to the predetermined grid distribution of the tools, in which firing pins are guided and biased by a compression spring against the respective tool held loosely in a tool plate;
• - That machining pins or steel nails are used in the holes of the tool plate as tools, the heads of which lie in vertical extensions of the holes and
• - That the tools are acted upon by the firing pin set in motion by the unbalance.

With such a machining device designed in accordance with the invention, stone surfaces, in particular concrete blocks, can be machined over such a large area that the desired impression of a hand-hammered stone surface is created, a finer or coarser surface structure being obtained by appropriately adjusting the machining intensity via the feed speed of the stone and can achieve the height adjustment of the swing frame and its horizontal swing width.

To initiate the vertical impact force, it is provided that the swing frame is provided on its upper side with guide bolts which are mounted in guide sleeves on the cross slide, and that connecting rods are swingably supported on one side on the cross slide, which on their other side carry a bearing for unbalanced shafts. These unbalanced shafts mounted on the oscillating frame are in turn supported by eccentrics in the other end of the connecting rods. Preferably, two unbalanced shafts are used which are driven in such a way that the unbalances mounted on them rotate in opposite directions to one another. Due to the counter-rotation of the unbalanced shafts and their eccentric mounting in the connecting rods, the counter-balanced unbalances create a directional vibration, due to which the firing pins mounted in the tool block are moved up and down and hit the individual tools guided in the tool plate in an irregular distribution. The force with which the firing pin strikes the tool can be adjusted by adjusting the height of the swing frame above the stone to be machined.

When operating such a stone processing device, it has been shown that the coordination of the masses participating in the movement is relatively critical if the mass of the unbalance with respect to the mass of the oscillating frame with the other masses attached to it and that of the tool block are not carefully coordinated with one another. An unpleasant companion Apparition of a misalignment of the masses are resonance phenomena, which also include the basic frame of the machining devices, in particular if the rotational speed of the unbalance is changed to change the machining depth. These resonance phenomena are particularly noticeable through undesirable transverse vibrations of the cross slide.

Since, depending on the type of surface treatment and the size of the stone surfaces to be processed, tool blocks of different widths or lengths and thus having different masses are used, it would be necessary to use interchangeable unbalances in order to obtain at least an approximate mass balance. However, this measure cannot be carried out in practical use.

In order to overcome these difficulties, the guide sleeves receiving the guide bolts are designed as pendulum sleeves, the pendulum sleeves being pivotably mounted on the cross slide. A mass balance weight is also attached to the guide bolts.

The bearings for the pendulum sleeves are attached to the cross slide via swing bearings, which serve to further dampen vibrations. The mass balance weight attached to the guide pin consists of a beam weight that rigidly connects the two guide pins together. This bar weight is interchangeable so that it can be adapted to changes in mass, e.g. result from tool blocks of different sizes. In this way it is achieved that with the help of beam weights of different sizes, the masses to be moved by the unbalances can always be adapted to the mass of the unbalances, which also enables a working mode in which relatively little vibration energy is transmitted into the construction frame of the machining device.

According to a special embodiment of the invention, it is provided that the tool block is provided with a plurality of perpendicular bores corresponding to the predetermined grid distribution of the tools, in which the firing pin is guided and biased against the respective tool by a spring. This prestressing by the spring is maintained in each case by a cover closing the bore.

Special chisels can be used as tools in the holes in the tool plate. However, it is provided in a particularly advantageous embodiment that the tools consist of steel nails which are inserted into the tool plate in such a way that their heads come to lie in countersunk extensions of the bores in the tool plate. With such, e.g. B. machining pins made of steel nails, unevenness of the stone layers can be compensated and, above all, the chamfers on the stone edges can be machined equally well as the horizontal surfaces.

To support the irregularity of the processing of the stone surface by the processing pins or steel nails, it is also provided that the bores in the tool plate are also countersunk from the outside of the plate in such a way that only a short one, the pin or. The corresponding bore section of the needle diameter remains. As a result, the steel nail or the machining pin is given greater lateral play by shortening the guide, and the formation of patterns during machining is avoided.

For a large-scale machining of concrete paving stones transported in lanes next to one another by the machining device, a special embodiment of the invention provides that the grid distribution of the holes for the machining pins or steel nails in the tool block from a field with at least four rows and more than 20 holes in a row there, the holes are offset from row to row a distance of about 1/3 to 1/4 of a hole spacing.

To adjust the horizontal oscillation width of the oscillating frame, it is provided that the cross slide is slidably mounted on horizontally extending shafts in such a way that the cross slide carries out an oscillating movement with a stroke of at least the distance between two adjacent tools or machining pins.

The shafts carrying the cross slide are held on oscillating bearings which, together with vertical slides arranged in the base frame, can be moved vertically in order to be able to adjust the tool holder on the oscillating frame according to the thickness of the stones.

• Fig. 1 eine teilweise geschnittene Seitenansicht einer Steinbearbeitungsvorrichtung gemäß der Erfindung;
• Fig. 2 einen Schnitt längs der Linie 11-11 der Fig. 1;
• Fig. 3 eine Stirnansicht auf einen der seitlichen Vertikalschnitte im Grundgestell der Bearbeitungsvorrichtung;
• Fig. 4 einen Teilschnitt durch den Werkzeugblock.
• Fig. 5 eine teilweise geschnittene Seitenansicht einer Steinbearbeitungsvorrichtung gemäß der Erfindung;
• Fig. 6 einen Schnitt längs der Linie 11-11 der Fig. 5.

The advantages and features of the invention also result from the following description of an exemplary embodiment. Show it:

• Figure 1 is a partially sectioned side view of a stone processing device according to the invention.
• Fig. 2 is a section along the line 11-11 of Fig. 1;
• 3 shows an end view of one of the lateral vertical sections in the base frame of the processing device;
• Fig. 4 shows a partial section through the tool block.
• 5 is a partially sectioned side view of a stone processing device according to the invention;
• 6 shows a section along the line 11-11 of FIG. 5th

1 and 3, the stone processing device according to the invention is mounted in a base frame 10, which consists of supports 13 connected to a lower cross member 11 and an upper cross member 12. From the upper to the lower cross member 13 parallel to the supports 13 guide rods 14 which are fixed to the cross members 11 and 12 in brackets 15. A vertical slide 18 is mounted adjustable in height within the frame 10. For this purpose, guide sleeves 19 are attached to the frame-like vertical slide on both sides, which are displaceable on the guide rods 14. With the help of an Upper cross member 13 mounted spindle 20, which runs down through the vertical slide 18 and is screwed into a flange nut 21 in the lower region of the vertical slide, the vertical slide 18 can be adjusted to any desired height.

On the top of the vertical slide 18, a plurality of swing bearings 22 are attached, which may consist of hydraulic bearings, for example. A support plate 23 is attached to the top of the oscillating bearing 22. This support plate carries two clamping blocks 24 symmetrically to the spindle 20 on its upper side.

To assemble the actual processing unit, two identical base frames 10 are arranged at a distance from one another and connected to one another by shafts 25, which are fixed in the clamping blocks 24. The actual processing unit is mounted horizontally displaceably on these shafts 25.

1 and 2, this processing unit consists of a cross slide 30 which consists of a base plate 31 and a stiffening frame 32 projecting downwards. Bearing webs 33 run parallel to the lateral end faces of the stiffening frame 32. Guide sleeves 34 are attached on the inside of the end faces of the stiffening frame 32 in the central plane. The base plate 31 is provided with a bore 35 over the guide sleeves 34.

Further guide sleeves 38, through which the two shafts 25 extend, are mounted on the top of the base plate 31 parallel to the end edges and at a distance corresponding to the distance between the shafts 25. The cross slide 30 is thus horizontally displaceable on the shafts 25 between the base frames 10. On one of the guide sleeves 38, a driver 39 is fastened, on which a push rod 40 engages, on the free end of which a crank, not shown, is effective in order to initiate the horizontal oscillating movement of the cross slide required for machining a stone. Guide bolts 42, which are fastened to a swing frame 43, run through the guide sleeves 34 and the bores 35. This oscillating frame 43 hangs on connecting rods 44 on the cross slide 30, which are required for controlling the vertical oscillating movement of the oscillating frame 43, as explained below.

The swing frame 43 extends over the entire working width and carries roller bearings 50 on both sides, in which an unbalanced shaft 51 is mounted on each side. On the unbalanced shafts 51, 50 unbalances 52 are fastened between the individual roller bearings, these being mounted on the shafts according to FIG. 2 in such a way that they lie symmetrically to the center plane through the oscillating frame 43 and the guide bolts 42. The unbalanced shafts 51 are driven on one side via a toothed belt wheel 55 and are connected to one another on the other side of the oscillating frame via spur gears 56, so that they carry out an opposite symmetrical rotational movement which initiates a directed vertical vibration in the oscillating frame due to the effect of the unbalances .

The vertical vibration is controlled with the aid of the connecting rods 44, which are mounted on the unbalanced shafts 51 via eccentrics 58. For this purpose, the unbalanced shafts 51 are shrunk into the eccentrics 58, which in turn are rotatably mounted in the connecting rods 44. This eccentric mounting of the unbalanced shafts 51 in the connecting rods 44 forces the oscillating frame 43 to move vertically relative to the cross slide 30, the oscillating frame being guided in the cross slide 30 by the guide bolts 42 and the guide sleeves 34.

A tool block 60 is fastened along the lower edge of the oscillating frame 43, in which the machining tools and firing pins are accommodated, which carry out their own movement due to the vertical oscillating movement of the oscillating frame 43 and apply force to the tools.

5 and 6, 30 bores 34 are made within the stiffening frame 32 in the base plate 31 of the cross slide, into which pendulum sleeves 134 protrude.

For the pivotable mounting of the pendulum sleeves 134, bearings 36 are mounted on swing bearings 37 on the top of the cross slide on both sides of the respective bore 34, in which the opposite pivot pins of the pendulum sleeve 134 are pivotably held.

The swing frame 43 extends over the entire working width and carries roller bearings 50 on both sides, in which the unbalanced shaft 51 is mounted on each side of the swing frame. This unbalance shaft 51 is connected in one piece to an unbalance 52. With the help of the roller bearings 50, the unbalances are mounted in such a way that they lie symmetrically to the center plane through the oscillating frame 43 and the guide bolts 42, as can be clearly seen from FIG. 6. At the two outer ends of the unbalanced shaft 51, pins 53 are eccentrically attached, which are supported on both sides in the connecting rods 44. The unbalanced shafts are driven on the right side in the illustration via a V-belt wheel 55 and are connected to one another on the other side of the oscillating frame via a dual toothed belt drive, so that they carry out an opposite symmetrical rotary movement which occurs in the oscillating frame due to the action of the eccentric Pin 52 initiates a directional vertical vibration.

The dual toothed belt drive used to synchronize the rotary movement is shown in detail in FIG. 6.

This drive comprises two spur gears 56 mounted on the unbalance shaft 51 and two idling spur gears 57, which are attached above and below the unbalance on one side of the swing frame.

The toothed belt is guided from a spur gear 56 to a free-running spur gear 57 and steered around the second spur gear 56 in such a way that it executes an opposite rotational movement with respect to the first spur gear. From the second spur gear 56, the toothed belt runs freely over the second de spur gear 57 back to the first spur gear 56. By using such a toothed belt, a high synchronization of the two imbalances is ensured, the low flexibility inherent in the toothed belt having a favorable effect.

4 shows a partial section through the tool block 60, from which the structure of the machining tool is shown in detail. The tool block consists of a mounting plate 61 which is fastened along the lower edge of the swing frame 43. The actual tool holder, which consists of a plate block 62 and a tool plate 63, is screwed against the mounting plate. The plate block 62 is preferably made of plastic, e.g. B. made of polyamide and has a plurality of holes 64 evenly distributed over the plate block. The holes are preferably made in a grid that consists of at least four rows with more than 20 holes, with a preferred embodiment having two grids with a total of 8 Rows and about 25 holes in a row are used. The individual holes are offset from row to row by a distance that is smaller than the distance between the holes. A displacement at a distance of about 1/3 to 1/4 of a hole spacing has proven to be particularly advantageous. By selecting the distance between the individual bores, you can influence the fineness of the machining so that, depending on whether you want finer or coarser machining, the distance between the bores is smaller or larger. The tool plate attached to the underside of the plate block 62 is provided with holes in the same grid distribution as the plate block 62. These holes are adapted to the tools used, which consist for example of processing pins in the form of steel nails 65. When using such steel nails 65, the bores 66 in the tool plate 63 on the side facing the plate block are countersunk to a depth such that the head 67 located at the upper end of the steel nail 65 comes to rest fully in the countersunk part. Furthermore, the bores 66 are countersunk from the underside of the tool plate to a depth such that only a short section, which corresponds to the diameter of the machining pin or the steel nail, remains. This measure ensures that the steel nail can move freely with a certain lateral deflection in the bore 66, which is particularly advantageous for the desired structuring of the bush stone surface as well as for the durability of the processing pins. The force applied to the steel nails or the machining pins is carried out with the aid of firing pins 70 which are longitudinally displaceable in the bores 64 and which are designed as solid steel bodies and correspond in length to approximately half the height of the plate block 62. Compression springs 71 are inserted into the bores 64 via the firing pin and are held in the bores 64 by means of covers 72. These covers 72 are clamped against the mounting plate 61 when the plate block 62 is screwed to it.

By initiating the vertical vibration in the swing frame 43, the firing pin 70 is moved up and down in the bore 64 and strikes against the steel nails 65, which are lifted by the stone pushed past and to be machined under the tool block 60, so that the up and swinging firing pin 70 directly hit the head 67 of the individual steel nail 65.

It is obvious that the height position of the tool block 60 above the stone to be machined, which can be adjusted with the help of the vertical slide 18, is of essential importance for the machining intensity, so that the grain size can be influenced by the height adjustment. The machining intensity and thus the structure of the stone surface are further influenced by the horizontal vibration width of the cross section 30 and the frequency of the vibration movement. Finally, the feed rate of the stone to be processed has a third factor. Through the use of the individual freely movable processing pins or steel nails and a suitable coordination of the influencing factors, the surfaces of concrete slabs or concrete paving stones can be processed so advantageously that they offer the impression of a natural stone surface or a manual stonemasonry. Unevenness in the stone layers is also leveled out and, above all, the chamfers on the stones are machined just as well as the horizontal surfaces.

As can be seen from the foregoing, the granularity of the surface can be varied within a wide range by adjusting the three main factors influencing the machining intensity. An additional range of variation results from the fact that different tool blocks are used, which differ both in the distance between the machining pins and their intrinsic diameters and in the weight of the firing pin.

The actual parts of the processing device that are subject to wear are the processing pins or steel nails, which must be replaced from time to time. For this purpose, the plate block 62 is unscrewed from the mounting plate 61 and the covers 72 are removed via the holes 64 which are assigned to the machining pins or steel nails to be renewed. After the compression spring 71 and the firing pin 70 have been removed, the steel nail or pin can be easily replaced. After the exchange, the firing pins and compression springs are reinserted and the bore 64 is closed with the cover 72.

Depending on the size of the stone surfaces and the type of processing, different tool blocks 60 can be used, these also having different masses. This changes the mass of the vibrating part in relation to the mass of the unbalance, which has a disadvantageous effect if the mass balance is disturbed. The invention therefore provides for mass compensation to provide a mass balance weight in the form of a beam weight 90 on the upper side of the guide bolts 42, which weight can be of different weights and is fixed to the guide bolts with the aid of screws 91. With the help of different beam weights, it is possible to adapt the mass of the oscillating frame and the tool block with the parts attached to them in relation to the mass of the unbalances and to carry out the desired mass compensation without having to change the mass of the unbalances.

It has proven to be particularly advantageous that with the help of the invention not only very massive concrete blocks, such as. B. concrete paving stones, but also relatively thin slabs can be processed, which are usually prone to breakage during mechanical processing. Due to the large, very dense processing of the stone surface, no extreme point forces are introduced into the material, so that the risk of breakage is significantly reduced, especially with slabs.

Claims (13)

1. Stone working apparatus for dressing stones including a plurality of working tools in a common, vertically movable tool holder in the form of a reciprocating frame (43) and a tool block (60) secured thereto, whereby each tool, which is mounted in a bore in the tool block (60), may individually have a force applied to it by an eccentric pivotal mounting of the tool holder in order to work the surface of a stone passed beneath it, characterised in that,

- a plurality of eccentric weights (52) is mounted on the reciprocating frame (43);

- that the reciprocating frame (43) is vertically movably mounted in a horizontally movable transverse carriage (30);

- that the tool block (60) is provided with a plurality of vertically extending bores (64) which correspond to the predetermined grid distribution of the took (65) and in which strikers (70) are guided and are biassed by a compression spring (71) against the respective tool (65) which is loosely mounted in a tool plate (63);

- that inserted as tools in bores (66) of the tool plate (63) there are working spikes or steel nails (65) whose heads (67) are received in vertical enlargements of the bores (66) and

- that the tools (65) are acted on by the strikers which are caused to oscillate by the eccentric weights (52).

2. Working apparatus as claimed in Claim 1,
characterised in that,

- the reciprocating frame (43) is provided on its upper surface with guide pegs (42) which are retained in guide sleeves (34) on the transverse carriage (30) and

- that pivotally mounted on one side on the transverse carriage (30) are connecting rods (44) which on their other side carry a bearing for eccentric weight shafts (51).

3. Working apparatus as claimed in Claim 1 and 2,
characterised in that,

- the guide sleeves receiving the guide pegs (42) are constructed as oscillating sleeves (134);

- that the oscillating sleeves are pivotally mounted on the transverse carriage (30) and

- that a mass compensating weight (90) is connected to the guide pegs (42).

4. Working apparatus as claimed in Claim 3, characterised in that,

- the bearings (36) for the oscillating sleeve are secured to the transverse carriage by oscillating bearings (37).

5. Working apparatus as claimed in Claim 3 or 4,
characterised in that,

- the mass compensating weight is a beam weight (90) connecting the guide pegs (42).

6. Working apparatus as claimed in one of Claims 1 to 3, characterised in that,

- the eccentric weight shafts (51) mounted on the reciprocating frame (43) are supported in the connecting rods (44) by eccentrics (58).

7. Working apparatus as claimed in one or more of Claims 1 to 6, characterised in that,

- two eccentric weight shafts (51) are used which are so driven that they rotate the eccentric weights (52) in opposite directions in synchronism with one another.

8. Working apparatus as claimed in Claim 1, characterised in that,

- the spring biassing is maintained by a respective lid (72) closing the bore (64).

9. Working apparatus as claimed in Claim 1, characterised in that,

- the bores (66) in the tool plate (63) are provided from the exterior of the plate also with countersunk broadenings (68) in such a manner that only a short bore section of the bore (66) corresponding to the nail diameter is present.

10. Working apparatus as claimed in one or more of Claims 1 to 9, characterised in that,

- the grid distribution of the working spikes or steel nails in the tool block comprises a field with at least four rows and more than 20 bores in a row, whereby the bores are offset from row to row by a distance of about 1/3 to 1/4 of a bore pitch.

11. Working apparatus as claimed in Claim 10,
characterised in that,

- at least 8 rows with at least 20 working spikes or steel nails are present in the tool block.

12. Working apparatus as claimed in one or more of Claims 1 to 11, characterised in that,

- the transverse carriage (30) is slidably mounted on horizontally extending shafts (25) in such a manner that the transverse carriage performs an oscillating movement with a stroke of at least half the spacing of two adjacent tools.

13. Working apparatus as claimed in one or more of Claims 1 to 11, characterised in that,

- the shafts (25) carrying the transverse carriage (30) are mounted on oscillating bearings (22) which are vertically movable together with horizontal carriages (18) in a base frame (10).

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