Machine for Repairing and Sealing Conduits

A solution had to be found on how to repair damaged conduits when they are too small in diameter and therefore inaccessible for reparation. The solution lay in a remote control machine which can execute the following tasks:

1. Preparation for the Repairing:

The damaged areas must be machined and cleaned. This includes tasks such as drilling out, brushing out, washing and siphoning.

2. Actual Repairing:

This includes putting in various filling materials such as plastics, adhesives or other materials, which have been made for these special applications by cement chemistry.

All of these said tasks require numerous supply lines which one must be able to interchange simply and quickly. Furthermore, such a repairing machine must possess the following abilities:

1. The tool must be able to be moved three-dimensionally, which includes:

running in the axial direction of the pipe

rotation about the axis of the pipe

radial shifting of the tool or toolholder from the center of the pipe to the wall of the pipe or vice versa.

2. It must be possible to inject products into or machine certain areas with the movements named in point 1.

A further important problem, which additionally had to be solved, was the solution to the problem of how one can lead the various, occasionally thick supply lines through the narrow pipe past the machine, which takes up a lot of space, and connect them to the rotating tool holder, which is located at the head of the vehicle, without having to use complicated rotating joints which are prone to break down.

Such vehicles have already been developed since 1976 by the applicant for this patent, which is a front-ranker in this area. See, for example, Swiss Pat. No. 7618/80-6, filed Oct. 13, 1980, to Sigel. This is a model which is suitable for sealing normal, damaged areas somewhere in the pipe, as well as for the more difficult sealing of damaged forks.

It is possible with this, as well as with further designs to simultaneously execute a rotation about the axis of the pipe and a radial movement towards the center of the pipe or towards the wall of the pipe, using a camera or a tool. Such further developments, which consist of a carriage equipped with a driving mechanism, a television camera and a tool holder, and are constructed for repairing damaged pipes, were already shown by the patent applicant before 1984 in exhibitions and demonstrations in Switzerland, as well as abroad. This includes demonstrating this remote-controlled rotation component in Berne, in Friederichshafen, at the Ingenieur-de-ville Conference in Bordeaux and at the Entsorga in the Gruga Hall in Essen, just to mention a few examples.

A quick follow-up on this project was hindered at first by serious shortcomings in the chemistry of repairing. It has particularly been demonstrated that the sealing gel employed up to now (e.g. Penetrin) dries out very fast because it contains around 70% water, and thus, gets brittle within a short time as soon as the ground water level temporarily sinks. Fine hair cracks develop in the dried out sealing material and ruin the extremely expensive repair work after a short time.

This is why no really satisfactory repairing machines for repairing and sealing inaccessible conduits have existed on the market until today. Especially the problem of how to realize the complicated mechanics, required for simultaneous rotational and radial movements of the toolhead, in a simple way, was not and could not be solved.

With the invention in question, a repairing machine has been successfully constructed, in which all of the disadvantages mentioned have been eliminated. It has particularly been succeeded to construct a movable head which solves all of these movements, such as axial rotation and radial shifting, with very simple mechanics. At the same time, a complicated rotating joint, prone to defects, can be foregone by leading the supply lines centrally through the machine. In other constructions, in which the supply lines were led around the machine in a zigzag and inevitably became tangled during rotation of the head, an execution without rotating joints was out of the question. Now, however, with the new type of construction at hand, having a central channel for the lines, the twisting can be intercepted by the remaining lines behind the robot vehicle.

With this new design, a device has been found which fulfills all requirements, and with which, for example, TV inspections, machining or product injections can be executed with no problem in inaccessible pipes or cavities. This, however, is also due to the fact that, besides the general surveying camera, an additional detail camera was mounted onto the tool plate, with which the area to be machined can be observed close up. Also the fact that rotations of over 360.degree. are possible aids in being able to execute repairs on the seams to the full extent, and therefore neatly, without leaving untidy edges at the beginning or end of the seams.

The drawing FIGURE is a top view of a robot vehicle in accordance with this invention.

The fundamental component of this robot vehicle thus consists of the driving carriage as it is already known from the patent dated Oct. 13, 1980. This is, however, additionally equipped with a motor-driven rotatable toolhead for placing tools or repair materials.

Repairing machines of various sizes can be employed for repair work in the lines. For pipes and lines with a diameter of 30 cm and less, a model is employed, which is driven by an additional motorized carriage and thus has no driving motor of its own for the wheels. For pipes with a diameter of more more than 30 cm, a larger model can be employed, which has its own drive and is intended for individual-wheel drive as each wheel has its own motor. Depicted in the drawing is the top view of the smaller robot vehicle, in which it is clearly shown that the control lines 10 for hydraulics, water, air, sealing material and the supply line for the television camera, etc. are no longer led around the vehicle on the outside, but instead, centrally through the vehicle. During rotation of the entire rotation component, incl. the revolving platform 7, together with both of the "duck bills" 6 on which the tools can be mounted, and the television, the control lines no longer get wound around the vehicle, but instead, the entire line simply experiences a small torsional rotation. This torsional rotation is achieved by a geared engine which turns the central rotation element 5 together with the control lines over a turntable 4. This rotation is controlled by an electric brain and the pilot valve in the steering-control holder 11. In this way, a rotation of at least 420.degree. can be achieved by the new device at hand, as such a large rotation can be offset by the rest of the control line between the take-up coil and the robot vehicle.

As previously mentioned, there is a revolving platform 7, on which two turnable lever arms, or "duck bills", 6 are mounted, attached to the central rotation element 5. Various tools such as drill, injector, television camera, etc. can be mounted on these "duck bills" 6. A pneumatic drilling device 12 with a diamond drill is depicted in the drawing. During rotation of the rotation component with the control lines 10, the whole revolving platform 7, including the instruments mounted on it, likewise rotates. Now only a radial movement of the "duck bills" 6 is necessary so that the devices mounted on them can reach the inner wall of the pipe which must be repaired. This is accomplished in that both of the "duck bills" 6, which display movable lever arms, can be turned by thrusting rods 1. Both of the thrusting rods are set into thrusting movements by a geared motor over a sleeve 3.

As previously mentioned, the robot vehicle is equipped with two cameras. The first of these two is a large surveying camera, which can be swivelled towards the front in order to see in the running direction. It can also be turned backwards, however, so that the whole robot vehicle can be observed during the work. In this way, all movements of both "duck bills" 6, along with the instruments mounted on them, can be observed. Besides this large surveying camera, a smaller detail camera is mounted on the "duck bills" 6, with which the corresponding processes such as drilling or injection of plastic sealing material, for example, can be precisely observed close up.

As shown by the previous description, the mounted, movable "duck bills" 6, the thrusting rods 1 and the control lines 10 being run through the center of the robot vehicle have made it possible to successfully replace the more expensive apparatus, available up to now on the market, with a very simple construction. The consequence of this is that, in the future, the production costs for the whole device can be massively lowered and that the proneness to repairs will rapidly decrease.