WALL CLIMBING APPARATUS

The invention relates to a climbing apparatus for climbing non-horizontal surfaces, in particular for climbing essenially vertical surfaces such as walls of buildings and the like.

STATE OF THE ART

For the maintenance of buildings or ships or other large constuctions it is common to use an apparatus which can climb the outer walls of the construction to accomplish maintenance work such as cleaning, painting or even repair works. Such apparatus commonly use an exhaustion mechansim comprising vacuum units to be held on the surfaces which are at least non-horinzontal and mostly essentially vertical. The apparatus must be moveable along the surfaces so that the maintenance work can be carried out on the whole area of the surface. Therefore moving mechansims are provided, which move the apparatus along a non-horizontal surface in that the vacuum units of the exhaustion mechanism are activated alternately and moved relative to each other.

Such apparatus are for example known from US 4,664,212 or US 6,090,221 which use circulating belts provided with suction units on the outside. The suction units successively contact the surface and fix the apparatus to the surface while the belt is driven and moves the apparatus forward in the manner of a crawler vehicle. Such crawler apparatus have the disadvantage that they hardly can climb obstacles on a surface such es bracings, window frames or the like.

Therefore climbing apparatus have been developed that are able to alternately lift their vacuum units from the surface and move them relative to each other. In this manner spiderlike devices have been design, which move their legs comprising the vacuum units individually and lift them from the surface. But the legs of such spider devices are difficult to coordinate and therefore need a lot of resources which are lost for the actual maintenance work.

DE 198 35 038 shows a climbing apparatus which uses elongated retainers carrying several vacuum units in a row. The retainers are moveably relative to each other in one direction for moving the apparatus along a surface. The vacuum units of one retainer may be individually or in groups raised from the surface so that the retainer may be advanced relative to an adjacent retainer to move the apparatus. This apparatus may hardly be moved around corners or travel over even small steps.

In US 4,674,949 a climbing robot is described which comprises a rectangular first train which carries a second train that is moveable relativ to the first train. Jacks are provided at the corners of the first and the second train, which carry suction cups to be adhered to a surface. The first train includes two parallel longitudinal beams. A slide device extends from one beam to the opposite beam and is slideable on the beams. In the middle of the slide device a mounting suspension for the second frame is provided. The mounting suspension includes an actuator which ensures the rotation of the second train relative to the first train. So the second train may be translated along and rotated relative to the first train. The actuator is responsible to hold the second train on the first train. The actuator provides only one suspension point, which is located directly on the rotation axis between the first and second train. Such a single point suspension is a weak point hi the construction of the climbing robot. Especially because in operation of the robot the rotation axis is oriented mostly perpendicular to a vertical surface so that leverage forces act on the suspension point due to the weight of the second train.

OBJECT OF THE INVENTION

It is an object of the invention to provide a climbing apparatus that overcomes the disadvantages of the prior art, which runs along non-horizontal surfaces safely, easily transcends obstacles on the surface, is provide with a stable and robust construction, and may be used for a large variety of building maintenance works.

These objects are solved by a climbing apparatus according to claim 1. Preferred embodiments of such climbing apparatus are disclosed in the sub claims.

The present invention provides a climbing apparatus for climbing non-horizontal surfaces, which comprises a main frame and a sub frame, a translation moving unit arranged between the main frame and the sub frame, and a swivel unit also arranged between the main frame and the sub frame. The main frame and the sub frame each comprise suction units for temporarily fixing the main frame and the sub frame, respectively, to a non- horizontal surface. The main frame and the sub frame are moveable relative to each other along a translational axis by the translation moving unit and are rotatable relative to each other around a rotational axis by the swivel unit. The rotational axis is preferably in general perpendicular to the longitudinal axis, but may also enclose an angle other than 90° with the longitudinal axis.

The main frame and the sub frame comprise four legs which are provided with the suction units at their ends. The frames may also comrise only three legs or comprise five or more legs. The middle part of the main frame may be designed as a solid plate or a grid plate, which serves as a mounting plate for the functional parts of the climbing apparatus. The legs extend from the middle part of the main frame in direction to a surface such that the sub frame can be placed in the space between the legs below the middle part.

According to the invention the swivel unit comprises a circular swivel guideway arranged non-rotatably relative to the main frame and at least one guideway follower arranged non- rotatably relative to the sub frame, which is moveable along and guided by the circular swivel guideway. A swivel motor drives the at least one guideway follower to move along the circular swivel guideway and to rotate the sub frame relative to the main frame.

Preferably the circular swivel guideway is designed as a swivel carrier ring and the guideway follower is a swivel ring arranged concentrically next to the swivel carrier ring. The swivel carrier ring and the swivel ring function as a circular suspension area for the sub frame on the main frame or on parts connected to the main frame. The swivel carrier ring is preferably arranged on the translation moving unit, but can also be mounted directly to the main frame. The swivel ring is preferably arranged on an elevation unit mounted on the sub frame, but may also be mounted directly on the sub frame. The suspension area provides a large area of contact which is holding the sub frame during rotation of the sub frame relative to the main frame. And can provide a stable mounting of the sub frame relative to the main frame.

The guideway followers may also be provided as two, preferably three or more seperate followers. In case of two followers, they are advantageously positioned on opposite sides on the circular swivel guideway. In case of three or more followers, they are advantageously disposed equally spaced apart from each other on the circular swivel guideway. The seperate followers may also be arranged in groups. The followers are mounted on the sub frame directly or may be mounted to other parts, such as an elevation unit, arranged on the sub frame. In general it is sufficient if one of the followers is driven by the swivel motor. The at least one guideway follower or the swivel ring, respectively, may be located on the outer side of the circular swivel guideway, so that the inside of the circular swivel guideway is free for other parts or constructions such as fixation means, motors or the like.

In a prefered embodiment of the climbing apparatus the diameter of the circular swivel guideway is approximately of the same size as the width of the sub frame. So the at least one guideway follower or the swivel ring can be provides with attachment points on the outer edges of the sub frame. It is also possible that the followers or the swivel ring encircle the sub frame. The swivel unit of the climbing apparatus according to the invention provides an enlarged diameter of the rotation movement.

Between the circular swivel guideway and guideway followers, especially between the swivel carrier ring and the swivel ring, a ball bearing may be provided to facilitate the rotation movement, when the swivel ring or the guideway followers are driven by the swivel motor. The swivel motor may be a common electric motor which for example drives the swivel ring or the guideway followers by a gear transmission. Also a step up or a step down transmission is possible for a better control of the rotation movement. Alternatively also a belt drive or any other suitable drive may be used. The main frame can carry a maintenance means to accomplish the maintenance word on the surface of the building or thelike. The maintenance means can e. g. be provided as one or more robot arms, as cleaning or painting devices or other such devices.

The translation moving unit of the climbing apparatus according to the invention may include a screw rod rotatably connected to one of main frame and sub frame, a screw nut arranged on the other of main frame and sub frame, and a screw motor, which rotates the screw rod. The screw rod may e. g. be designed as a worm screw. Preferably the screw rod is held in bearings located on the middle part of the main frame in longitudinal direction of the main frame. The screw rod is rotatable within the bearings by the screw motor but is not moveable translationally relative to the main frame. The screw nut is arranged non rotatably relative to the main frame and the sub frame. Preferably the screw nut is mounted on a carrier means like a carrier plate which is provided for carrying the swivel unit, inparticular the circular swivel guideway.

The translation moving unit of the climbing apparatus also may include at least one guide rail arrranged on one of main frame and sub frame, and at least one rail slider arranged on the other of main frame and sub frame, wherein the rail slider fits on the guide rail such, that the rail slider is slidable along the guide rail but not separable from the guide rail. Preferably the at least one guide rail is arranged on the main frame, especially on the middle part of the main frame parallel to the screw rod. The at least one guide rail may have approximately the same length as the screw rod. Especially preferred two guide rails are provided spaced apart from each other and running parallel to each other, one on each side of the screw rod. The guide rails may be designed as a bar extending from the main frame in direction of the sub frame or may be designed as an embeded groove in the main frame. The at least one rail slider encompasses the guide rail bar or is anchored within the guide rail groove such that it may not fall of the guide rail. Preferably at least two rail sliders are provided on each guide rail. They can be spaces apart from each other by approximately the width of the sub frame. Preferably the two guide rails and the four rail slider of the two guide rails are spaced apart from each other such that they approximately describe a square which essentially has the size of the sub frame. Preferably the rail sliders are attached to the circular swivel guideway or a carrier means that carries the circular swivel guideway. At the end of the guide rails stops may be provided to stop the sliding movement of the rail sliders,

In one embodiment of the climbing apparatus according to the invention an elevating unit is arranged between the sub frame and the main frame, in particular between the sub frame and the at least one guideway follower or the swivel ring, respectively, to move the sub frame relative to the main frame translationally along the rotation axis. That means the sub frame may be moved perpendicular to the screw rod. So the sub frame can be elevated from a surface such that the suction units do not touch the surface anymore. The elevating unit may comprise one lifting unit for each connecting point between the at least one guideway follower and the sub frame. Also several lifting units may be arranged along the swivel ring and mounted to the sub frame at several connecting points. In particular the lifting units may be arranged on the swivel ring hi a square pattern and may be mounted to the sub frame. Preferably the lifting units are mounted on the sub frame on an outer edge of the sub frame. The lifting units are driven by an elevation motor, which is for example provided by an electrical motor. All lifting units of the elevating unit may be connected by a geared rods and may be driven by the same motor.

Besides the elevating unit to elevate the sub frame relative to the main frame the legs of the sub frame and the main frame of the climbing apparatus may be provided telescopically moveable relative to the main frame and the sub frame, respectively. With the telescopically moveable legs the middle part of the main frame may be lifted or lowered relative to a surface. By lifting or lowering the main frame the sub frame is also lifted or lowered, so that it may touch the surface or not. The telescopically moveable legs of the sub frame also allow the sub frame to contact or not to contact the surface. The telescopical legs of each frame can be driven by a common motor. Mostly the telescopical legs help to overcome obstacles, while the frames may themselves may remain their distance from the surface. In this case the legs may be telescopically lifted individual from each other.

The suction units of the climbing apparatus according to the invention are preferably provided at the end of each leg of the main frame and the sub frame. A suction unit comprises at least one suction cup, which is fixable to the surface by vacuum exhaustion. Preferably one suction units includes three suction cups. The vacuum exhaustion of the suction cups may be controlled uniform for all suction cups of the main frame or the sub frame or the suction cups may be individually provided with vacuum.

In general the climbing apparatus according to the invention may be controlled by a central computing unit, which is for example provided on the main frame. The central computing unit controls the several motors and the vacuum exhaustion of the suction units.

In operation the climbing apparatus according to the present invention will first be fixed to a non-horizontal surface by all suction units, that means by the suction unit of the main frame and the sub frame. To move the climbing apparatus further along the surface the adherence of the suction units of the sub frame is released and the legs of the sub frame are retracted into the sub frame and lifted from the surface. Simultaneously or subsequently the lifting units of the elevation unit lifts the sub frame away from the surface as well. Next the translation moving unit moves the sub frame relative to main frame along the translational axis by rotation of the screw rod so that the screw nut and the sub frame, which is connected to the screw nut, are moved along the screw rod. At the new position the sub frame is lowered by the elevation unit and/or the telescopical legs are extended until the suction units touch the surface again and fix the sub frame to the surface. In a second step the main frame is loosened from the surface by releasing the suction units and retracting its legs into the main frame. The swivel unit turns the main frame in the new moving direction of the climbing apparatus by rotating the at least one guideway follower on the circular swivel guideway so that the main frame rotates relative to the sub frame. In case of a swivel ring as guideway follower and a swivel carrier ring as circular swivel guideway the swivel ring is rotated relative to the swivel carrier ring. The swivel movement orientated the translational axis, the screw rod respectively, in the new moving direction Afterwards the main frame is moved translationally along the new translational axis by translation moving unit. In case during the movement large obstacles on the surface have to be overcome, which are larger than the retraction range of the telescopical legs of the main frame it is possible to raise the main frame further away from the surface by the elevation unit arranged between the main frame and the sub frame. The telescopical legs and the elevation unit together form a two-step raising mechanism for the main frame and the sub frame. In this manner obstacles of up to 160 mm of height can be passed. Of course the suction units of the main frame may be lifted first and the main frame is moved relative to the sub frame first as well.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention will be described in the accompanying drawings, which may explain the principles of the invention but shall not limit the scope of the invention. The drawings illustrate:

Fig. 1 cross-sectional front view of an embodiment of a climbing apparatus according to the present invention,

Fig. 2 cross-sectional side view of the climbing apparatus,

Fig. 3 bottom view of the main frame of the climbing apparatus,

Fig. 4 detailed view of the swivel unit of the climbing apparatus,

Fig. 5a cross-sectional side view of the elevating unit of the climbing apparatus,

Fig. 5b side view of the sub frame,

Fig. 6a detailed view of the translation moving unit of the climbing apparatus in a start position, Fig. 6b detailed view of the translation moving unit of the climbing apparatus in an end position,

Fig. 7a cross-sectional side view of the main frame with the telescoping legs, and

Fig. 7b bottom view of the main frame showing the driving assembly of the legs.

In figure 1 a climbing apparatus according to the present invention is shown in a cross- sectional front view. A main frame 1 is designed as a framework in the form of a square or rectangular form. It comprises a leg 13 at each corner of the framework and a middle part 36 from which the four legs extend basically parallel to each other in direction of a surface on which the climbing apparatus will be used. The legs 13 are telescopically slidable to retract the legs 13 into a body of the main frame 1. The middle part 36 carries a sub frame 2 that is of rectangular or square shape as well and is provided with four telescopically moveable legs 13'. A suction unit 3 comprising suction cups is arranged at the end of each leg 13 and 13' of the main frame 1 and the sub frame 2. The suction cups are orientated towards the surface.

At the bottom side of the middle part 36 the main frame 1 comprises a translation moving unit 24 including a horizontally orientated screw rod 9 and a screw motor 10 (not shown in figure 1). The screw rod 9 may be a conventional screw rod but is preferably designed as a worm screw. A screw nut 16 is movably arranged on the screw rod 9. The screw nut 16 is not rotatable relative to main frame 1 but to the screw rod 9 and therefore nut 16 moves along the screw rod 9, when the rod is rotated by the screw motor 10. The screw rod 9 is mounted on the bottom side of the middle part 36 of the main frame 1 and is seated within two bearings 37 which allow rotation of the screw rod 9.

Further there are provided two guide rails 7, which run parallel to the screw rod 9 on the bottom side of the middle part 36 of the main frame 1. The guide rails 7 are part of a guiding for the sub frame 2 when moving translationally along the main frame 1. The guide rails 7 are designed as bars with rounded tracks. Attached to the screw nut 9 is a sliding carrier plate 14 which basically runs parallel to the bottom side of main frame 1. The sliding carrier plate 14 comprises four rail sliders 8 which cooperate with the guide rails 7. The rail sliders 8 are provided with a circular inner groove which fits over the rounded tracks of the guide rails 7 such that they may slide along the guide rails 7 but can not be separated from the guide rails 7. The guide rails 7 and the rail sliders 8 are spaced apart from the screw rod 9, which basically is located in the center of the middle part 36 of the main frame 1. The guide rails 7 and the rail sliders 8 support the translational movement of the sliding carrier plate 14 relative to the mam frame 1, when it is moved along main frame 1 by the screw nut 16. The sliding carrier plate 14 is attached to the main frame 1 at several points: the screw nut 16 on screw rod 9 and the four rail sliders 8 on the guide rails 7. This design ensures a save and strong suspension construction for the sub frame on the main frame.

The sub frame 2 also is designed as a rectangular framework. The sub frame 2 is attached to an elevation unit 4 and a swivel unit 5, which will be described in more detail below. The swivel unit 5 is arranged at the sliding carrier plate 14. The sub frame 2 is movable along the screw rod 9 by the translation moving unit and may be lifted towards and away from the bottom side of the middle part 36 of the main frame 1 by the elevation unit 4. Further the sub frame 2 is rotatable relative to main frame 1 by the swivel unit 5.

In figure 2 the climbing apparatus of the invention is shown in cross-sectional side view. The sub frame 2 with the telescopically legs 13' is arranged between the legs 13 of main frame 1 and below the middle part 36 of the main frame 1. The screw rod 9 is held by the bearings 37 below the middle part 36 and driven by screw motor 10. The nut 16 sits on the screw rod 9 and is connected to the sliding carrier plate 14. The swivel unit 5 and the elevation unit 4 are arranged below the sliding carrier plate 14 and connected to the sub frame 2. Four lifting units 17 of the elevation unit 4 hold the sub frame 2 at the outer edge of the sub frame 2. In figure 2 the sub frame 2 is in a middle position relative to the main frame 1. It can be moved to a left or right position as will be shown in figures 6a and 6b.

Figure 3 is a view on the bottom side of the main frame 1. The guide rails 7 stretch out along the length of the middle part 36 of the main frame 1. The guide rails 7 are located at the edge of the middle part 36, so that they are spaced apart as far as possible to provide a secure guiding. The rail sliders 8 sit on the guide rails 8 and are spaced apart about the same distance as the two guide rails 7. Therefore the rail sliders 8 are lying on a virtual circle.

In figure 4 parts of the swivel unit 5 are shown from below. The swivel unit 5 includes a circular swivel guideway m form of a swivel carrier ring 15 and a guideway follower in form of a swivel ring 21 concentrically arranged to the swivel carrier ring 15 and rotatable relative to the swivel carrier ring 15. A ball bearing is arranged between the swivel carrier ring 15 and the swivel ring 21. The swivel unit 5 comprises a swivel motor 11 which rotates the swivel ring 21 relative to the swivel carrier ring 15. The swivel carrier ring 15 is connected to the sliding carrier plate 14 and therefore is rotationally fixed relative to the main frame 1. The elevation unit 4 is arranged at the swivel ring 21 so that the elevation unit 4 and therefore the sub frame 2 connected to elevation unit 4 is able to rotate relative to the main frame 1. The diameter of the swivel carrier ring 15 and the swivel ring 21 is approximately of the same size as the width of the middle part 36 of the main frame 1. The swivel carrier ring 15 and the swivel ring 21 may extend beyond the guide rails 7.

In figur 5a the elevation unit 4 is shown which comprises four lifting units 17 each with a moving block 18 connected to the sub frame 2 and a vertically orientated guide rod 19, along which the moving block 18 is moving up and down, e. g. by a screw connection. The moving blocks 18 are driven by a common elevation motor 12 which transmits driving force to the blocks 18 by a driving gear 20. The driving gear 20 may be designed as a bevel gear. In figure 5b the elevation unit 4 is shown attached to the sub frame 2. The blocks 18 of the lifting units 17 catch the sub frame 2 at side planes of the sub frame 2. The suction cups of the sub frame 2 can make use of a two step raising mechanism to raise the suction cups 3 of the sub frame 2 away from a surface on which the climbing apparatus is working. First the legs 13' may be telescopically retracted in the sub frame 2 and second the whole sub frame may be elevated by the elevating unit 4. Of course the telescoping legs 13' and the elevating unit 4 may run at the same time or in succession after each other. With the two step mechanism the climbing apparatus can easily run over even high obstacles.

In figure 6a a schematical view of the translation moving unit is shown. The screw nut 16 is in a right position which may be the starting position for a translational movement of the sliding carrier plate 14 which is connected to the sub frame 2. When the screw rod 9 is rotated by motor 10 within the bearings 37 the screw nut 16 is forced to move along the screw rod 9 because of the screw connection and the rotational fixation of the nut relative to the main frame. The. rotational fixation in e. g. provided by the mounting of the sliding carrier plate 14 on the main frame by the cooperation of the guide rails and the rail sliders. The screw nut 16 may travel over the length of the screw rod 9 until it reaches the left position as shown in figure 6b. The movement of the screw nut 16 is stopped by the bearing 37 of the screw rod which serves as an end stop. When the screwed rod 9 is rotated in the other direction by motor 10 the screw nut 16 can move back from the left to the right position.

Figure 7a a telescope unit 6 provided for the telescoping movement of the legs 13 and 13' is shown. The telescope unit 6 comprises a leg motor 22 and three rod elements 23, 23', 23" for each leg 13 or 13' which are linked up to each other. The motor 22 is located at the center of the main frame 1 or the sub frame 2 respectively as shown in figure 7b. The first rod element 23 is connected to the motor 22 by a bevel gear. The second and the third rod elements 23', 23" are connected in row to transmit a rotation of the first rod element 23 to the third rod element 23". By rotation of third rod element 23" the legs 13 and 13' of main frame 1 and sub frame 2 respectively are retracted relative to the frame e. g. by a screw connection.

The climbing apparatus according to the invention is usable as a robot which is capable of climbing plain vertical surfaces such as windows and facades of buildings or other constructions. The climbing apparatus may support other devices e.g. for the treatment of the surfaces or the buildings preferably on main frame 1 but also on sub frame 2. The climbing apparatus is fixable to the surface by vacuum exhaustion of suction cups of suction units 3 arranged at the legs 13 and 13' of the sub frame 1 and the sub frame 2.

For vertical and horizontal movement of the climbing apparatus along a non-horizontal surface inparticular vertical surfaces the main frame 1 and the sub frame 2 may be moved relative to each other in a translational and a rotatable manner by the translation moving unit 24 and the swivel unit 5. While treating a surface the climbing apparatus may be stationary or may be moved along the surface. The climbing apparatus is connected to a safety rope secured e. g. on the top of a building or construction, which secures the climbing apparatus against dropping off.

Translational Movement:

When the suction units 3 of the main frame 1 fix the climbing apparatus to the surface the sub frame 2 may be lifted from the surface by the elevation unit 4 (all four lift units 17 work simultaneously) and the legs 13' of sub frame 2 may be retracted into the sub frame 2 by telescope unit 6. Then the screw motor 10 drives the nut 16 on screw rod 9 along screw rod 9. The sub frame 2 is arranged at the sliding carrier plate 14 which is connected to the screw nut 16. While driving the screw nut 16 along screw rod 9 the rail sliders 8 on the sliding carrier plate 14 slide along the guide rails 7 at the main frame 1 and aid to guide the translational movement of the sub frame 2 relative to the main frame 1. At the new position the sub frame 2 is lowered relative to the main frame 1 and the legs 13' of sub frame 2 are extended until the suction unit 3 reaches the surface. Then the suction cups of the suction unit are fixed to the surface by vacuum exhaustion. For further translational movement the suction units 3 of the main frame 1 are released from the surface and the legs 13 of the main frame 1 are retracted into the main frame 1, so that the main frame 1 is loosened from the surface. Next the main frame 1 is transported along the sub frame 2 by the translation moving unit 24 as mentioned above.

Rotational Movement:

To change the moving direction of the climbing apparatus the main frame 1 and the sub frame 2 may be rotated relative to each other. When the main frame 1 is in the lifted position the swivel carrier ring 21 is rotated relative to the swivel ring 15 by swivel motor 11 so that the main frame 1 rotates relative to the sub frame 2. The main frame 1 may be rotated by 360°. At the new rotational position the legs 13 of main frame 1 are lowered to reach the surface and the suction units 3 fix it to the surface. In the same manner the sub frame 2 may be lifted from the surface and rotated relative to the main frame 1.

The climbing apparatus can travel large distances on a surface by repeating the translational and rotational moving steps along any straight or curved pathway or over large obstacles. It will be understood by a person skilled in the art, that the circular swivel guideway and the guideway follower may be designed in a different manner than described in figures 1 to 7. In particular the swivel ring does not necessarily be designed as a full ring but may be provided as one or more ring segments which are mounted in a fixed position towards each other. BEZUGSZEICHENLISTE

main frame 20 driving gear up/down sub frame 21 swivel ring suction unit 22 leg motor elevation unit 23 rod element swivel unit 24 translation unit telescpe unit 36 middle part guide rail 37 bearing rail slider screw rod screw motor swivel motor up/elevation motor legs sliding carrier plate swivel carier ring nut on screw rod lift unit moving block guide rod