EP0681627A1

EP0681627A1 - Method of laying paving stones and an associated laying device

Info

Publication number: EP0681627A1
Application number: EP95902083A
Authority: EP
Inventors: Harald Kleinemas
Original assignee: OPTIMAS MASCHINENFABRIK H KLEINEMAS GmbH
Current assignee: OPTIMAS MASCHINENFABRIK H KLEINEMAS GmbH
Priority date: 1993-11-26
Filing date: 1994-11-22
Publication date: 1995-11-15
Also published as: PL310006A1; JPH08509279A; CZ193395A3; AU1107695A; WO1995014821A1

Abstract

According to the proposed method of laying paving stones, paving stones (3) which are stacked are picked up by the laying device (1) by means of a grab (4) in a grabbing motion, lifted, conveyed to the laying site and deposited. Also disclosed is an associated laying device (1). The method and device simplify the operational process, improve the speed of the process and reduce errors by the incorporation of a sensor (13) to trigger the grabbing motion when the grab (4) is in position.

Description

Process for laying paving stones and laying device therefor

The invention relates to a method for laying paving stones according to the preamble of claim 1 and a laying device for this purpose according to the preamble of claim 10.

Paving for walkable and navigable surfaces is popular not only because of the design options, but also because of the absorption capacity for surface water and the durability that can be achieved with a comparatively simple substructure, since they can adapt to deformations or subsidence of the subsurface to a considerable extent. In the case of large-scale paving, the possibility of mechanical laying is of last importance, in which it has been possible to transport a whole layer of a delivered stone package and to the laid paving using laying vehicles over the freshly laid, not yet vibrated and grouted paving start. This has made it possible to drastically rationalize the laying work previously carried out manually by paving and to multiply the daily performance of the skilled workers. This now largely mechanized way of working has been perfected, which under the normally prevailing additional conditions, such as the adaptability to different plastering tasks and justifiable effort, can hardly expect drastic performance improvements.

ORIGIN _A DOCUMENTS At the same time, work has been made easier, in which the high demands of heavy work close to the ground in a kneeling or bent position have been replaced by the much easier operation of a laying device. Here, too, there have been various attempts to make the driver's seat area ergonomic and work easier and to improve performance, but the previous options are only "small steps" in this regard.

The typical, recurring activity of the skilled worker now consists of swinging back and forth with the laying device between a stack of stones provided, for example, on a pallet and the boundary of the fresh plaster advancing with laying work, an entire layer of the stack of stones to grasp the edges of stones in rows and rows with a gripper, to lift them, to transport them and to set them flush at the edge of the paving with the previously laid paving. In addition to the steering work during transport, the workload and the working speed are determined from the operations that are to be carried out as precisely and quickly as possible, in which there are typical sequences of processes such as aligning, closing, lifting the gripper in the area of the stone stack or Aligning, opening and lifting the gripper on the pavement edge is possible.

The object of the invention is now to provide a method for laying paving stones or a laying device therefor, which moreover makes possible significant simplifications in work and simplifications and thus also substantial increases in performance during laying. According to the invention, this object is achieved by a method according to the preamble of claim 1 with the characterizing features of claim 1.

It has been shown that the mechanical laying work is not difficult, but is nevertheless strenuous, since the large number and the quickest possible succession of precise operations when tapping and placing the stones is tiring. This means that even a skilled and experienced worker can only maintain a high working speed for a limited time. In the event of a decrease in concentration, the reliable execution of the operating functions always has priority, since stones picked up incorrectly from a stack of stones and falling down, as well as stone layers incorrectly attached to the previous paving, result in a malfunction with time-consuming and cumbersome clearing-up and repair work call.

If, however, an automatic triggering can be achieved in the gripping movement by a sensor triggering the gripping movement when the stack of stones approaches or touches the stone movement, the worker can be relieved of a particularly delicate and demanding part of his operating work . He only needs to bring the gripper into a gripping position by, for example, placing the gripper on the stack of stones in order to thereby automatically trigger a preceding alignment movement, but otherwise in any case the gripping movement and preferably also the subsequent lifting movement. In the meantime, the worker can already do his next step, namely the transport of the stone layer dedicate .

A very corresponding improvement can be achieved when the stone layer is set down with an automatic setting movement of the stones triggered by a sensor, namely when the gripper controls the opening and lifting of the gripper when the stone layer is placed on the freshly paved edge.

It has been shown that such an automatic function triggered by a sensor signal not only reduces the workload and thus the workload, but in particular also creates very considerable improvements in performance. Working speeds, such as can sometimes be reached by skilled personnel in phases, are now easily maintained.

A corresponding sensor signal can be obtained in various ways. In principle, it is thus possible to determine whether the gripper is in the gripping position by means of a mechanical button arranged in the area of the gripper, by a proximity sensor operating contactlessly with light, ultrasound or the like, by a light barrier and the like. In the first place, an approach or an installation with respect to the stone stack is monitored.

Placing the gripper on the stone stack and the associated weight relief can be monitored even more simply and robustly, which also has special advantages for use in civil engineering. This is also possible in various ways, for example also with weight sensors, strain gauges in the area of the gripper suspension or pressure load cells. Is even easier However, in the case of the pressure medium-operated gripper suspensions that are used throughout, a sensor monitors the load on the pressure medium and thus determines that the gripper is resting. It is also advantageous that this pressure monitoring can be carried out in an encapsulated machine area of the laying device and thus in a weather and dirt-protected area.

In the case of the simple weight monitoring of the gripper, it is expedient to mask out false signals which could arise, for example, from rocking of the laying vehicle while driving. In the simplest case, short-term signals are suppressed that are significantly less than one second, e.g. up to a quarter of a second.

The aforementioned sensor monitoring can be used accordingly when the stones are deposited. Here too, contact sensors or non-contact sensors, for example on the side of the gripper facing the driver's cab of a laying vehicle, can detect a close approach to the ground, ie to the pavement that has already been laid, and can completely lower and open the gripper in order to do so then pull up. Here too, however, with a weight monitoring of the gripper or with a pressure monitoring for an associated pressure-medium-actuated drive, there is a simple determination that the gripper is attached in order to trigger the corresponding sequence of depositing functions and the retraction of the gripper.

It goes without saying that if the same sensor signal, that is to say the pressure reduction in a hydraulic actuator for lifting the gripper, both for the gripping process and for the Solving process should be used, a distinction is important. In the simplest case, a circuit can be provided which triggers functions that change with each additional sensor signal, that is, once the gripper closes and once the gripper opens, along with the accompanying functional sequences.

However, a more reliable combination of the sensor signal with additional signals, for example also a sensor signal for the weight of the gripper or for the pressure in a pressure circuit, to a pressure-medium-actuated actuator for the gripper, from which it can be seen whether the gripper carries a position of stones, so that the next operation must be a triggering operation or whether the gripper is empty so that a gripping operation must follow. It goes without saying that additional signals can also be entered by hand, just as it is possible to mask out false signals by means of a manual switch. However, efforts are preferably made to save simple and uncritical operations in order to make work easier.

The aforementioned object is also achieved by a laying device according to claim 10, which realizes the functions explained above, in particular a sensor for the impact of the gripper on a stone stack and / or on a laying edge.

An embodiment of the invention is shown in the drawing and will be described in more detail below. The drawing shows:

Fig. 1 to a laying device for laying

Fig. 3 of paving stones in different Working positions,

Fig. 4 front view of a gripper

Laying device according to FIGS. 1 to 3 in the open position and

Fig. 5 gripper of FIG. 4 in side view in gripping position.

In FIG. 1, a mobile laying device, designated overall by 1, takes the uppermost one from a factory-made stone package 2 with a number of stone layers 3 lying one above the other

Location, which for example has an area of approx.

2 1 m in rows and rows of adjacent stones. Each layer of stones should be laid in such a way that the laying device moves over the freshly laid paving and the layer of stones is flush with the edge of the previously laid paving (Fig. 2) and is applied there as an extension of the paving (Fig 3). The laying device then moves back to the stone package, fetches the next layer 3 from this stone package 2 and in turn places it on the edge of the paving, so that the paving progresses layer by layer. A laying device of the type in question is known for example from DE-PS 29 10 719.

In these processes, it is important that the gripper grabs the stones cleanly, since it has to hold and transport them by pressing against (at least) two opposite sides and forming bridges. Typically, as can be seen from FIG. 4, a stone pliers 4 are equipped with a number of gripping jaws 5 lying next to each other on both sides of the gripping pliers 4, each pressing individually on a curb of the stone layer 3 to be detected, so that tolerance errors not from stone to stone Pressure errors and thus lead to the stone layer collapsing during lifting and transport.

So that the stone rows to be gripped are aligned and aligned with one another and with respect to the gripping tongs, the gripping tongs 4 furthermore comprise alignment strips 6 and 7 which pivot on swivel arms 8 and 9 with the aid of an actuator 10 transversely to the gripping jaws 5 against a stone layer which Move stones together without gaps and align the gripper 4 with respect to the stone position. Only after this alignment can the gripping jaws 5 grasp and pick up the stones, the gripping pliers shown being intended to be a "mechanical" gripper in the sense that the own load of the gripper and the stone position detected by it is not (shown in detail) ) Lifting mechanisms are converted into gripping forces, so that there is a smooth transition between gripping and lifting in a uniform lifting movement of a suspension 11 for the gripping tongs 4. It goes without saying that in the present case a hydraulic gripping actuation is also used, in which the gripping jaws 5 are pressed together by hydraulic cylinders. In this case, the operations to be triggered as quickly as possible, but in exact succession, are the alignment by means of the straightening bars 6, 7, the closing of the gripping tongs by moving the gripping jaws 5 and the lifting of the gripping tongs on the suspension 12. Errors in the succession the movements in the sense that the gripping jaws 5 already grasp before alignment or that the gripping tongs 4 raise before the gripping jaws 5 have gripped, easily lead to the stones falling out and to lengthy and labor-intensive malfunctions.

5 shows a further hydraulic actuating member 11 to recognize, which bridges the lever mechanism of the mechanical gripper 4 and allows the gripper to open. This actuator is actuated when the laying vehicle has arrived at the laying location and the stone layer still held in the gripping tongs 4 has found its place for laying down, as shown in FIGS. 2 and 3. The straightening strips 6 and 7 must then be folded up from the pressure position according to FIG. 5 into the position according to FIG. 4. The gripping jaws 5 must be released to release the stone layer, the gripping tongs 4 must then be raised so that they come free from the ground for the return journey and the laying vehicle must be switched and steered for the return journey to the stone package.

It has been shown that the workload involved in laying paving stones has hitherto been caused by critical phases in picking up the stones from the parcel and applying them to the paving. This strain is particularly burdensome in that relatively quick work is possible, for example with work cycles that recur every minute. According to the invention it is now provided to trigger the gripping process and expediently also the placing process by a sensor control and to let it run automatically. When picking up the stones, for example, not only the gripping itself, but also a previous alignment and the subsequent lifting of the pliers can be controlled automatically. Likewise, the placement of the stones can be carried out automatically by the sensor control, so that the driver only has to make an effort to move to the stone package or the place of installation precisely, but not at these critical points still have different pulling, gripping and lifting movements or Check triggering and lifting movements and have to control.

In the present exemplary embodiment, a sensor 13 in the form of a hydraulic pressure sensor is used for this purpose, which monitors the pressure in a hydraulic actuator 14, which in turn moves a boom 15 holding the gripping pliers 4 vertically.

If the driver of the laying device 1 approaches the stone stack with advantageously inclined gripping tongs 4 (FIG. 1) and thereby pushes on and / or hangs up the gripping tongs, this leads to a relief of the boom 15 and to a pressure drop in the actuator 14, which is caused by the Sensor 13 is perceived and reported to an electrical control 16, which then precisely aligns the control sequence to be observed by hand, neither with this precision nor at this speed, by means of the alignment bars 6, 7, gripping the stones and lifting the gripping pliers 4 causes. In this process, the driver can already prepare subsequent travel movements of the laying device.

The same applies when the installation site according to FIG. 2 is reached. When the driver has reached the installation site and the stone layer held in the gripping tongs 4 has brought pressure against the edge of the already laid paving, a lowering of the gripping tongs 4 is sufficient in order to rest when the Stone position and / or the gripper 4 to achieve a pressure drop in the actuator 14, which is sensed by the sensor 13 and reported to the controller 16. The controller 16 thus triggers the opening of the gripper and then its raising. In the present exemplary embodiment, the sensor 13 delivers a practically identical signal when the gripper strikes the stone package or the installation site, but this should result in the stones being picked up and lifted and the stones being released. In the simplest case, an alternating function could be installed in the control circuit 16, which alternately triggers a gripping process or a release process after each signal signal. However, this requires a certain amount of monitoring insofar as a double touchdown should lead to malfunction. Instead, it is additionally provided that the signal from the sensor 13 is also recorded and evaluated with regard to the preceding load. So if the sensor indicates that the gripper was empty before touching down, a gripping process is triggered. If the gripper was previously loaded with a layer of stones, a release process is triggered. Likewise, detectors for the height position of the gripper can be installed which - when the gripper is high on the stack - trigger a gripping or when the gripper is deep, they are put down.

Furthermore, protection against false triggering in the event of brief weight relief of the gripper is preferably provided. If, for example, the gripper is relieved for a short time while driving by rocking the vehicle, for example for less than a quarter of a second, this signal is suppressed by a signal circuit of a basically known type. Only a relief signal that is present for a longer time is accepted and evaluated as a proper sign of the gripper being placed in the control circuit 16. The example given here of a sensor in the form of a pressure sensor results in a particularly simple and practical design. It goes without saying that the placement of the gripping tongs 4 on the stone package or on the depositing point can be monitored by different weight sensors or load sensors on the tongs or on the boom. However, it is also entirely possible to provide proximity sensors of a mechanical or electronic type on the gripping tongs, which monitor the approach of the movable tongs to the fixed target points in the form of the stone package or the paving edge and thus trigger a corresponding sequence of the movements .

The control functions are preferably carried out electrically or electrohydraulically with regard to control elements which are commercially available. However, it is entirely possible to create pliers functions of the type in question here with purely hydraulic or purely mechanical control elements. For example, a hydraulic control can be designed in such a way that valves for releasing successive functions are only actuated when the preceding function has been completed.

Claims

Expectations:

1. Method for laying paving stones, in which laying stones provided in layers by a gripper with at least one pair of gripping jaws by means of the gripper (4) are gripped and lifted in layers in a gripping movement, conveyed to a laying location and on be set off from this, characterized in that the gripping movement is triggered by a sensor signal generated by a sensor (13) when the gripper (4) arrives.

2. The method according to claim 1, characterized in that the sensor signal is obtained by measuring the load exerted by the gripper (4) on the laying device (1).

3. The method according to claim 2, characterized gekenn¬ characterized in that the sensor signal is obtained from a pressure measurement in a hydraulic suspension of the gripper (4).

4. The method according to any one of claims 1 to 3, characterized in that in addition to the gripping movement, a lifting of the gripper (4) is triggered by the sensor signal.

5. The method according to any one of claims 1 to 4, characterized in that the gripping movement is triggered with a time delay and that the gripper (4) of the gripping movement leads an alignment of the stones.

6. The method according to any one of claims 1 to 5, characterized in that an opening of the gripper (4) is triggered by a sensor signal when the stones are set down.

7. The method according to claim 6, characterized gekenn¬ characterized in that the sensor signals for the gripping movement and the closing movement of the gripper (4) from a sensor (13) are obtained and distinguished by linking with additional signals.

8. The method according to claim 7, characterized gekenn¬ characterized in that the additional signals are obtained by measuring the gripper load.

9. The method according to claim 7, characterized gekenn¬ characterized in that the additional signals are stored as memory signals for the changing opening / closing state of the gripper (4).

10. laying device for paving stones with a movable gripper having at least one pair of gripping jaws for receiving a layer of paving stones in a gripping movement which detects the stones on the edge, with at least one gripper drive for local movement of the gripper and for its gripping movement, and an associated drive control tion, characterized by a sensor (13) commanding the drive control (16) and monitoring the arrival of the gripper (4).

11. Laying device according to claim 10, characterized in that the sensor (13) is a load sensor responsive to the load of the gripper (4) to be carried by the laying device.

12. Laying device according to claim 10 or 11, the gripper of which is moved at least in the vertical direction by a pressure medium-operated drive, characterized in that the sensor (13) monitors the pressure of the pressure medium.

13. Laying device according to claim 10 or 11, characterized in that the load sensor is a weight sensor arranged between the gripper and the other laying device.

14. Laying device according to one of claims 10 to 14, characterized in that an evaluation circuit is connected to the sensor.

15. Laying device according to claim 14, characterized in that the evaluation circuit contains at least one signal memory for an actual value of the gripper.

16. Laying device according to claim 14, characterized in that the evaluation circuit is connected to a hand-operated switch in a driver's seat area.

17. Laying device according to claim 14, characterized gekenn¬ characterized in that the evaluation circuit is connected to a detector for the height of the gripper.