DEVICE HAVING A SURFACE DISPLACEABLE IN TWO SPATIAL DIRECTIONS

Abstract

A device having a surface displaceable in two spatial directions, including a carrier frame; a conveyor means disposed such that it circulates on the carrier frame in a first direction; a plurality of belt units, each belt unit being fastenable to the conveyor means in such a way that it is displaceable in the first direction, and each belt unit including: a first continuous belt that is disposed such that it circulates on the belt unit in a second direction; and a first driving roller for driving the first continuous belt in the second direction; each first driving roller being actuated by a dedicated drive; and each belt unit additionally has a second continuous belt that is situated on the belt unit parallel to the first continuous belt.

Description

The present invention relates to a device having a surface that is capable of being displaced in two spatial directions.

Conventional treadmills have a surface that is displaceable in one spatial direction, usually parallel to the ground or slightly inclined relative thereto, so that a jogger can move forward relative to this surface while remaining essentially at rest inertially. This makes it possible to travel, as it were, arbitrarily long distances forward or backward while staying in the same place. Vertical treadmills, sometimes provided with artificial grips, analogously enable an upward climbing movement. In both cases, a continuous belt circulates in one spatial direction, so that the upper side of the upper run (as a rule the load run) forms the desired surface displaceable in this spatial direction. However, disadvantageously, here it is possible to realize only a relative movement having one degree of freedom; i.e., the user can move forward or backward only in this spatial direction relative to the surface.

Therefore, EP 0 948 377 B1 proposes an omnidirectional treadmill whose surface can be displaced in two independent spatial directions. With such a treadmill it is possible, as this document proposes as a preferred application, to realize in particular an artificial environment (“virtual reality,” or VR). In this context, the user can move in the two spatial directions as desired relative to the surface without essentially changing his inertial position relative to the surrounding room. If a visual system, such as VR goggles or surrounding VR monitors, are connected to the system in such a way that the environment displayed thereon changes in a manner corresponding to the displacement of the treadmill, this can convey to the user the subjective feeling of moving in this environment.

In this connection, it is to be noted explicitly that, in contrast to EP 0 948 377 B1, the present invention is not limited to spatial directions that are essentially perpendicular to the direction of gravity, i.e. essentially parallel to the ground. The present invention equally comprises for example an essentially vertical surface that is displaceable both vertically and horizontally, and that can thus simulate for example climbing upward and laterally.

In a first variant, EP 0 948 377 B1 realizes the displacement in the two spatial directions in that a continuous belt circulates in a first spatial direction. The continuous belt has individual bodies, in particular cylinders or balls, that are capable of rotation about an axis parallel to the first spatial direction, so that at its uppermost circumferential point there results a relative speed in a second spatial direction perpendicular to the first spatial direction. The rotation of the individual bodies is imparted via frictional contact with a second continuous belt that circulates under the first continuous belt, perpendicular to the direction of circulation thereof, on which second belt the individual bodies roll under friction. Disadvantageously, what is known as pivoting friction is present at the point of contact between individual bodies and the second continuous belt, because the individual body is drawn in the first spatial direction over the second continuous belt, which is moving rapidly in the second spatial direction, so that the body has relative speed in the first and second spatial direction at the same time.

In a second variant, EP 0 948 377 B1 proposes that the individual bodies be replaced by belt units in the form of individual continuous belts situated next to one another, each circulating in the second spatial direction. The displacement in the second spatial direction is imparted to the individual belt units by rollers whose axis of rotation is oriented parallel to the first direction of displacement and via which the individual continuous belts are drawn along by frictional contact. Here as well, pivoting friction disadvantageously occurs between the outer side of the lower run of an individual continuous belt and the rollers, because the bell units are displaced both in the first and in the second spatial direction relative to the rollers.

This pivoting friction increases wear and limits the drive forces that can be transmitted. It thus disadvantageously limits the achievable displacement speeds, reaction times, and load capacities.

Therefore, from U.S. Pat. No. 6,669,012 B1 a device is known having a plurality of belt units that are displaced in a first spatial direction by two conveyor chains. Each belt unit comprises a first continuous belt that is situated on the belt unit so as to circulate in a second spatial direction and is actuated by a servomotor. The accommodation of the servomotor and of the control and transmission devices connected thereto requires significant constructive depth of the individual belt units in the spatial direction perpendicular to the first and second directions. During circulation of the deflecting rollers of the conveyor chains, the individual belt units tilt about an axis parallel to the second spatial direction. For this purpose, due to the mentioned constructive height of the individual belt units significant gaps must be present between two adjacent belt units.

Therefore, U.S. Pat. No. 6,123,647 proposes as an alternative that one or both of the rollers over which the continuous belts of the individual belt units circulate (i.e., rollers whose axis of rotation during the upper and lower run phase is parallel to the first direction of displacement) be driven by a pinion that engages in a respective toothed rack when the individual belt unit is in the upper run phase. The axes of rotation of the pinion and toothed racks are oriented parallel to the first direction of displacement, and their circumferential toothings lie in the plane of the second direction of displacement. Because here the rotational movement of the individual continuous belts in the second direction of displacement is now imparted not by friction but by a positive-fit connection via pinion and toothed rack, the above-mentioned pivoting friction can be reduced.

The two rollers over which the continuous belts of the individual belt units travels are each connected to a conveyor belt that circulates between each two pulleys in the first direction of displacement. During rotation of the drive disks, the pinions tilt about an axis of rotation that is parallel to the second direction of displacement. Therefore, disadvantageously, here as well intermediate spaces must be provided between the individual belt units, the size of the spaces being on the order of magnitude of twice the width of the pinion. If it is desired to advantageously realize a closed surface, U.S. Pat. No. 6,123,647 proposes that the pinions of adjacent belt units be offset relative to one another in the third spatial direction, perpendicular to the first and second spatial direction. In this way, the individual pinions can tilt without interference when running in and out of the drive disk. However, on the other hand this disadvantageously requires a second toothed rack, so that the pinions of adjacent belt units engage in the first or second toothed rack in alternating fashion.

The device known from U.S. Pat. No. 6,123,647 has some disadvantages. For example, at the beginning of the upper run phase, i.e. when a belt unit runs away from the deflection of a drive pulley and the upper side of its continuous belt becomes part of the usable surface, the pinions must be brought into engagement with the toothed racks. This requires an expensive synchronization of the pinion rotational speed to the rotational speed of the toothed racks. Conversely, before running into the other drive pulley and being changed over thereby to the lower run phase, the pinions must first be taken out of engagement with the toothed racks. Both when the pinions move into or out of engagement with the toothed rack and during the running of the pinion into or out of the drive pulley, shocks occur that disturb the uniform displacement of the surface, and that also place considerable stress on the components, in particular the drive train.

Based on the above considerations, the object of the present invention is to make available a device having a surface that is displaceable in two spatial directions that avoids the above-named disadvantages of the prior art.

For this purpose, according to the present invention a device as recited in the preamble of claim 1 is developed by the characterizing features thereof.

A generic device having a surface displaceable in two spatial directions comprises a carrier frame, a conveyor means that is situated on the carrier frame circulating on the frame it in a first direction and a plurality of belt units, each belt unit being fastenable on the conveyor means in such a way that it is displaceable as a whole in the first direction. Each belt unit comprises a first continuous belt that is situated on the belt unit and circulating on the unit in a second direction and a first driving roller for driving the first continuous belt in the second direction. Preferably, the first and second directions are essentially perpendicular to one another.

Each first driving roller is actuated by a dedicated drive. In order to keep the gaps between the successive individual belt units as small as possible, and simultaneously to enable a tilting of the belt units during deflection, according to the present invention each belt unit also has at least one second continuous belt that is situated on the belt unit parallel to the first continuous belt. The second continuous belt can be fashioned flatter than the first continuous belt in a direction perpendicular to the direction of conveyance of the conveyor means and perpendicular to the direction of circulation of the first or second continuous belt, so that the gap between successive belt units, necessary in order to enable the lower edges of the belt units to pivot past one another, can be reduced. In each belt unit, a second continuous belt can be situated at one side of the first continuous belt of the belt unit. It is equally possible to provide one or more second continuous belts at each side of the first continuous belt.

The second continuous belt can be driven by a second driving roller or by the first driving roller in order to drive the first continuous belt in the second direction.

As is known from U.S. Pat. No. 6,123,647, a certain minimum distance must be maintained between belt units that circulate or travel in the first direction and that have a finite expansion in this direction, said distance permitting a tilting of the belt units during the deflection at the drive wheels. According to the present invention, for this purpose in a device according to the present invention each belt unit comprises the second continuous belt that is situated on the belt unit parallel to the first continuous belt, the first and second continuous belt having the same speed of circulation.

Thus, in contrast to U.S. Pat. No. 6,123,647, here it is not necessary to provide a second toothed rack. The actuation of both driving rollers via the same drive ensures that both continuous belts have the same circulation speed, so that the surface is given a homogenous speed field.

The first and/or second driving rollers may preferably be cylindrical, but may for example equally have a polygonal cross-section.

Preferably, the first and second continuous belts are fashioned such that belt units situated next to one another form an essentially closed surface. Advantageously, here the second continuous belt can be somewhat shorter and/or flatter. so that space remains for a corresponding gear mechanism, for example in the form of chains, toothed wheels, or toothed belts, between the drive and the driving rollers. In particular, the second driving roller can have a smaller diameter than the first driving roller, so that an open space is formed under the second continuous belt, in which supports, conduits, mechanisms, sensors, or the like may be situated without having to change the gap width between two belt units.

A device according to the present invention also does away with the other disadvantages explained above. Because the continuous belts are not actuated via frictional contact as in EP 0 948 377 B1, the pivoting friction that occurs there does not occur in the present invention, reducing the associated wear and also the transmission of large drive loads. Correspondingly, it is also possible to realize large surfaces displaceable in two spatial directions, providing a person situated thereon with a large radius of action, in particular extended stride lengths or the like.

In comparison with U.S. Pat. No. 6,123,647, here no toothings engage or disengage with one another, so that the associated run-in and run-out shocks are avoided and the displacement of the surface is more uniform. In addition, the problems connected with toothings are avoided, such as changing rigidities due to the different number of teeth that are engaged, as well as a longitudinal torsion of the toothed racks, which makes precise controlling of the rotational movement of the continuous belts more difficult.

Advantageously, the separate drives are connected in series, making it possible to supply the required energy from an inertially stationary source to one of the drives, from which it is transmitted to the other drives in succession. At the same time, this also enables a homogenous controlling of all the drives, so that all the continuous belts circulate in the second direction with the same speed. This makes it possible to displace the overall surface formed from the individual continuous belts homogenously in the second direction.

In an alternative embodiment, the individual drives can also be controlled individually, so that surface areas having different speeds can also be realized in the second direction. For this purpose, the individual drives can be remotely controlled, for example via radio or infrared signals.

It is equally possible for the drives to be controlled by a data bus, which can preferably be situated parallel to the energy supply, or by sensors, for example roll levers or reed contacts, in such a way as to be deactivated after the run-in to the deflection from the load run phase and to be reactivated upon runout from the deflection into the load run phase, in order to save energy and to avoid unnecessary dynamic excitations. Advantageously, the (de-)activation takes place continuously during a specified span of time, in order to avoid spikes in the energy supply and in the speed of the continuous belts. In a preferred embodiment, here the motors can also be connected to a common energy supply, parallel to one another.

The drives of the driving rollers can comprise for example electric motors. In a preferred embodiment, the drives comprise hydraulic motors that are connected in series by hydraulic lines. Here, each hydraulic line advantageously connects two adjacent hydraulic motors. Hydraulic motors are particularly suitable for use in a device according to the present invention due to their quiet running, their damping properties, and their high power.

For the supply of energy, the carrier structure preferably has a linear guide that can be displaced in the first direction and on which there is situated an endless rotating feedthrough for the supply of energy to a drive, connected thereto, of a driving roller. If the drives comprise electric motors, the linear guide can be connected by a first line to an inertially stationary voltage source. Via the endless rotating guide, the electrical energy is then supplied to one of the electric motors, from which it is then transmitted to the other drives connected in series thereto. In the preferred embodiment having hydraulic motors, the linear guide is connected to an inertially stationary pressure source in an analogous manner. The hydraulic pressure is fed to a hydraulic motor in a constructively simple manner via the endless rotating guide, and from there is transmitted to the other motors connected in series.

Alternatively, the supply of energy to the one drive can also take place via a pre-tensioned line that is inertially stationary at one side, the pre-tensioning preventing the line from sagging. For this purpose, for example the line can advantageously be unwound from an inertially stationary drum against a resetting torque.

During the circulation of the belt units in the first direction, the drive connected to the endless rotating guide carries the energy supply, with back-and-forth displacement of the linear guide. During the deflection of the belt units from a displacement in the first direction to the opposite direction, the endless rotating guide enables a corresponding rotation of this drive. Thus, in a constructively simple manner all drives of the belt units can be supplied with energy from an inertially stationary energy source.

Advantageously, the carrier structure comprises a support structure in order to support the continuous belts of the belt units. This makes it possible to realize relatively large surfaces that can accommodate large loads perpendicular to the surface.

Preferably, this support structure is fashioned in such a way that a connection between the continuous belt feedthrough and the drive connected thereto in the second direction, approximately in the center of the appertaining belt unit, can circulate along with this belt unit in the first direction. This permits the surface to be supported over almost its entire width, and is particularly advantageous if the loads are widely distributed or concentrated at the edge, as is the case for example with multi-axle wheeled vehicles. Equally, the connection can also circulate in the first direction at another location, for example at the edge of the surface, so that the surface is supported in particular in the central area, in which the main load is usually located.

The conveyor means preferably comprises two circulating chains, each circulating in the first direction through the action of at least one drive wheel. In order to avoid, or at least reduce, the polygon effect that occurs here, the run-in of each chain to the associated drive wheel can advantageously have a guide surface in order to guide the chain, said surface essentially comprising two linear segments that are essentially parallel, two segments, preferably clothoidal, having changing inclination with constant curvature, and a circular segment, in such a way that the chain goes from a first linear segment, in which it runs essentially in the first direction, with a constant curvature into a first, preferably clothoidal segment having changing inclination with constant curvature, and from here goes with constant curvature into the circular segment, then going from this segment with a constant curvature into the second, again preferably clothoidal segment having changing inclination with constant curvature, and from here goes with constant curvature into the second linear segment. In this way, the deflection of the individual belt units at the drive wheel takes place almost without shocks, enabling a particularly uniform displacement and further reducing the wear on the device associated with shocks. As is known, a clothoid is a curve in which the curvature changes in linear fashion with its length, in particular a curve in which the product of the curve radius and the curve length is constant.

Advantageously, each chain can be actuated by a first and a second drive wheel situated at the beginning or end of the circulation path of the chain. In order to avoid shear loading of the belt units, the first and/or second drive wheels of both chains are preferably each controlled with angular synchronism; electric motors are particularly well-suited for this.

Preferably, the drive wheels are fashioned as polygonal wheels that can enter into positively fitting engagement with bolts of the respective chain. This enables actuation of the chains with very little play and with low wear.

It is equally possible to use toothed belts, rigid chains, and/or a magnetic linear drive as a conveyor means. The latter advantageously makes it possible to provide fewer belt units, because in the idle run phase they can circulate faster. In this way, it is possible to provide only the number of belt units required to form the surface on the one hand and in addition to replace the belt units running out therefrom. To a first approximation of a continuity equation, the number of belts can be reduced by approximately half the number of belts required for complete equipping, divided by the increase in speed in the idle run phase. Thus, in a device in which the belt units are circulated in the first direction by a magnetic linear drive and are conveyed back in the idle run phase at twice the speed, the number of belts can be reduced by one-fourth (half, divided by twice the speed) in comparison with full equipping.

Preferably, each belt unit can comprise a traction device by means of which the continuous belt can be drawn to a carrier structure of the belt unit. For example, a magnetically reactive continuous belt can be drawn using a magnet. Equally, the continuous belt can also be drawn to the carrier structure by a partial vacuum created by a vacuum device. This advantageously compensates lateral forces, in particular ill the first direction, on the continuous belts, thus also permitting vertical use as an artificial climbing wall.

Further objects, advantages, and features result from the subclaims and from the following exemplary embodiments.

FIG. 1 shows a device according to an embodiment of the present invention in a perspective view;

FIG. 2 shows the device of FIG. 1 in a front view;

FIG. 3 shows the device of FIG. 1 in a side view;

FIG. 4 shows a view corresponding to FIG. 2, with belt units removed;

FIG. 5 shows an individual belt unit in a perspective partial view, with a first continuous belt partly removed;

FIG. 6 shows a drive wheel with sectioned belt units, in a schematic perspective representation;

FIG. 7 shows the drive wheel of FIG. 6 in a side view;

FIG. 8 shows the hydraulic circuit plan of a valve;

FIG. 9 shows a drive wheel with an actuated chain in a perspective partial view; and

FIG. 10 shows a linear guide with an endless rotating feedthrough for the energy supply.

FIG. 1 shows a device having a surface displaceable in two spatial directions according to an embodiment of the present invention, in a perspective view. The device comprises a carrier frame 11 that is shown in more detail in FIG. 4.

As can be seen in FIGS. 6, 7, and 9, a conveyor means 16, in the form of two link chains, surrounds the carrier frame in a first direction. Each chain comprises, in a known manner, inner and outer elements 44, 45, connected to one another in jointed fashion by bolts 46 (FIG. 9). In order to displace the chains in the first direction, a first and a second drive wheel 18 each engage in each chain 16, said drive wheels being fashioned as polygonal wheels and driven by a first electric motor M10 or M20 or by a second electric motor M11, M21. Advantageously, first and second electric motors M10, M20 or M11, M21 are controlled with angular synchronism so as to avoid shear stress on the device. Preferably, the front drive wheels (in the direction of displacement) draw the chains, and the rear drive wheels (in the direction of displacement) rotate along with approximately the same speed, so that the chains do not have to transmit any tensile forces in order to overcome the friction of these rear drive wheels and their electric motors. When the first direction of displacement is reversed, the first and second drive wheels exchange their roles as front or rear drive wheels.

The drive wheels are fashioned as polygonal wheels that can enter into positive engagement with bolts 46 of the respective chain.

A plurality of belt units 20 are fastened permanently or detachably to the chains, so that the belt units are displaced along with the chains in the first direction. As is shown in FIGS. 6, 7, for this purpose there are situated on chain elements 44, 45 holding clips 43 with which each belt unit can be brought into engagement. Here, all possible types of fastening are conceivable, including in particular screws, locking connections, snap connections, clamping connections, bayonet locks, or the like. Advantageously, the connection between the belt unit and the conveyor means permits a certain rotation about an axis that is essentially perpendicular to the first and second direction, in order to compensate manufacturing tolerances and asynchronicities of the conveyor means.

In FIG. 5, a belt unit 20 is shown in more detail. It comprises a first endless or main belt 22 (FIG. 2) that is partly hidden in FIG. 5. It circulates on the belt unit in a second direction that is oriented essentially perpendicular to the first direction, actuated by a first driving roller 23.

Each first driving roller is actuated by a dedicated drive that in the exemplary embodiment is fashioned as hydraulic motor 26. This motor drives first driving roller 23 via a tractor belt 24.

In addition, each belt unit comprises a second continuous or support belt 21 that is situated on the belt unit parallel to the first continuous belt and that is driven in the second direction by a second driving roller 28. The second driving roller is driven via a tractor belt 25, together with first driving roller 23, by drive 26 of the belt unit in such a way that the first and second continuous belts have the same speed of circulation.

In a modification (not shown) of the exemplary embodiment, first and second driving roller 23, 28 can also be combined to form a common driving roller.

The carrier structure comprises a linear guide 71, shown in more detail in FIG. 10, that is displaceable in the first direction and on which there is situated an endless rotating feedthrough 72 for the supply of energy to a drive, connected thereto, of a driving roller. In this way, the energy, for example electrical power or hydraulic pressure for electric or hydraulic motors 26, can be transmitted from an inertially stationary energy source, connected for example to carrier frame 11, to linear guide 71 via a flexible line that permits displacement in the first direction, and from there can be transmitted via endless rotating feedthrough 72 to a drive motor 26 that is connected to a rail 74 permanently or via an elastic component, in particular a spring 77, which itself is connected permanently or detachably to endless rotating feedthrough 72.

As can be seen in FIG. 4, in which the belt units are hidden for clarity, the carrier structure comprises a support structure 17 for supporting the continuous belts of the belt units, in such a way that connection 74 (FIG. 10) between the endless rotating feedthrough and the drive connected thereto in the second direction, approximately in the center of the appertaining belt unit, can circulate or travel together with this belt unit in the first direction. In this way, the first and second continuous belt of each belt unit can be supported over a wide area, making it possible to enlarge the surface displaceable in two spatial directions enough that relatively large movements on the surface are possible; for example, a person can jump on it. Alternatively, the narrow area that has to be left open by support structure 17 for the above-mentioned supply of energy can also be provided in a different area, for example at the edge of the surface.

Hydraulic motors 26 are connected in series; that is, starting from the hydraulic motor that is connected to rail 74 and to which hydraulic pressure is applied via the linear feedthrough and the endless rotating feedthrough 72, 73, this hydraulic pressure is supplied to all the hydraulic motors of all the belt units successively via hydraulic lines between adjacent hydraulic motors. This permits a very simple, disturbance-resistant supply of energy, and minimizes the movable parts of the energy chain between the inertially stationary energy source and the drives circulating in the first direction.

As can be seen in particular in FIGS. 7 and 9, the run-in of each chain to the associated drive wheel has a guide surface 19 in order to guide the chain, essentially comprising two linear sections that are essentially parallel, two clothoidal segments 13, and a circular segment, in such a way that the chain goes from a first linear segment, in which it runs essentially in the first direction, with constant curvature into a first clothoidal segment, and from here goes with constant curvature into the circular segment, and then goes from this segment with constant curvature into the second clothoidal segment, and from here goes with constant curvature into the second linear segment. Here, in the clothoidal segments the product R(s)·s of the curvature radius R(s) and curve length s is constant, which enables a continuous transition of the linear segment (radius of curvature R(0) infinite) at the beginning of the curve (curve length s=0) to the circular segment having curvature radius or circular radius RE, avoiding run-in and run-out shocks as well as the polygon effect.

In the following, an embodiment of the present invention is explained in terms of the individual assemblies of the device.

As stated, the basic construction of the device consists of carrier frame 11 having a running surface on which belt units 20 are displaced, and that comprises a guide surface 19 in the area of the drive wheels. The device can be divided into two functional areas: carrier frame with main drive (11-19) and belt units (20-41).

Using a total of four motors M10, M20, M11, M21, the main drive drives drive chains 16. Belt units 20 are fastened to these drive chains 16 by holding clips 43. Each belt unit itself consists of two belts 21 and 22 that are driven via common motor 26.

Construction of the Belt Units

FIG. 5 shows the construction of the belt unit. First, or main, belt 22 is partially hidden here in order to show the inner workings. Main belt 22 is driven by a driving roller 23, and second or support belt 21 is driven by deflecting roller 28. Support belt 21 here has a significantly smaller constructive height than does main belt 22. In addition, support belt 21 is realized in such a way that it terminates flush at the outer side of frame 33. As soon as a plurality of belt segments 20 are situated next to one another, there arises a closed surface made up of belts 22, 21. Deflecting rollers 23 and 28 are connected to drive 26 by drive elements 24 and 25. The connection can be realized for example as a toothed belt drive. Here, the gear ratio in each case is chosen such that the belts are displaced with identical speed. Drive element 26 is realized as a leak-free hydraulic motor. Given an arrangement of a plurality of belt units 20, a precise synchronism or ganging can be achieved through a serial connection of drive elements 26.

For the advantageous controlling of the motor, in addition a proportional hydraulic valve 30 can be used as a bypass, switched by a sensor 31. As soon as the belt on chain 16 leaves the horizontal position on the upper side of the device, in the run-in to deflection 13, the bypass is activated and belts 21, 22 come to a halt due to friction. This prevents malfunction (“running off” of belts 21, 22 from the guide) of belt unit 20, for example a halting in the vertical position at the deflection with simultaneous driving by motor 26.

An energy supply provides energy to the belt. This supply is constructed in such a way as to facilitate the serial arrangement of belt units 20. The supply of energy takes place at a belt unit 20 that is supplied by flexible supply line 76. The energy is then successively forwarded in the chain of belt units 20 until the train again reaches first belt unit 20, which, depending on the medium, brings the return line into the energy train.

For the accommodation of lateral forces, belt 21 and 22 is equipped with suitable guide elements. An advantageous embodiment here is for example trapezoidal profiles welded onto the underside of the bell, which slide into correspondingly shaped grooves of the run surface.

In order to improve the spatial expansion of the belt and the dynamic properties connected therewith, the drive element and the controlling are housed largely within the belt element. On the remaining free area underneath the support belt, supports 27 are attached at intervals, which can accept forces with a support roller 29 held on bearings. As soon as belt unit 20 is situated on the upper side of the device, these supports are in contact with running rails 17 of carrier frame 11. In this way, forces of almost any magnitude exerted by objects on the device can be accepted without having to reinforce frame 33 of the belt unit; this is very advantageous with regard to the weight and dynamics of the device. In addition, the arrangement can be made almost arbitrarily wide.

The bypass of drive motor 26 can in addition be constructed very advantageously, which has a significant effect on the costs and operating safety. in the proposed advantageous arrangement shown in FIG. 8, the bypass is activated by a sensor 60. This sensor can be realized for example as a roller lever valve. As soon as a sensor is activated, a fluid flows into piston 62, whose speed of movement is limited by adjustable throttle check valves 61. The piston actuates a hydraulic valve whose degree of opening is proportional to the actuation path. In this way, after a switching process of the sensor the bypass is opened or closed with adjustable speed, the opening and closing times being settable independent of one another. This results in a smooth curve of the line pressure without pressure shocks, resulting in a constant speed of all belt units 20.

Main Drive Train

Belt units 20 are connected to main drive train 16 via a respective holding clip 43. Main drive train 16 is constructed from inner elements 45 and outer elements 44, which are fastened via bolts 46 so as to be displaceable. On bolts 46 there are mounted running wheels 41 that roll on a running surface with deflection. Holding clip 43 for belt segments 20 is mounted on an element pair (44 and/or 45). Main drive train 16 is driven by a segmented wheel 18 that engages in bolts 46 on the inner side between a pair of elements 45. The segmented wheel is advantageously constructed in such a way that after the engagement has taken place the positive fit of bolts 46 with wheel 18 is ideal (exact fit, hardening of segmented wheel 18), and main drive train 16 is automatically centered by a beveling on the outside of the tooth edges of segmented wheel 18.

Run-in 19 is shaped especially in order to avoid the known polygon effect at chain edges, above all given large spacings. It also serves to prevent what is known as the lash effect, in which belt segments 20 have a tendency, given a jump in the curvature of the running belt, to strike against the adjacent belt segments 20. The transition 19 from the running surface to the deflection takes place with a constant curvature. The beginning of the deflection is advantageously realized as a clothoid 13. In this way, a sudden jump in acceleration is avoided, and the belt units 20 separate from one another without shocks. As soon as the clothoid has inclination and curvature identical to that of the corresponding circular arc of polygonal wheel 18, deflection 13 goes from the clothoidal shape to the circular path. With the beginning of the circular path, the complete contact of a bolt 46 with polygonal wheel 18 is also created. The run-out is fashioned in the same way as the run-in. At the transition from the circular path to the clothoidal shape, bolts 46 become separated from polygonal wheel 18. Subsequently, belt segment 20 is continuously braked in its rotation about its longitudinal axis, and finally, at the transition to the linear run surface 19, makes contact without shocks with belt segment 20 traveling in front of it.

A precise synchronism of the two main drive trains 16 is particularly advantageous, because otherwise the entire device may be destroyed. For this purpose, each of the two main drive trains 16 is equipped with two drive elements M10, M11 or M20, M21. These drive elements are advantageously fashioned as electric motors having a gear mechanism and a control unit.

In order to displace main drive trains 16 in the direction of drives M10, M20, the following controlling is provided: M10 and M20 are controlled with angular synchronism, and are held in exact synchronism by the control unit, using rotary sensors in a closed control loop. The motors at the opposite side, M11 and M21, are charged with a constant moment in the running direction that is sufficient to displace the motors and the gear mechanism themselves but not to exert relevant forces on the main drive train. The purpose of this is so that motors M11 and M21 will not be dragged by main drive trains 16, which would result in increased wear and destruction. The movement in the opposite direction takes place in analogous fashion, but the motors are exchanged: M10→M11 and M20→M21. In order to brake the device, the braking force is applied by the drive motors that are situated opposite those required for the acceleration. For example, if, as shown, the driving is accomplished by M10, M20, then the braking force is applied by M11, M21, M10, M20 are again charged with a constant moment in the running direction in order to prevent the gear mechanism and motors M11, M21 of main drive train 16 from being driven by the inertia of the moved masses in a manner similar to a generator. Correspondingly, here the braking force is greater than the moment at M11, M21.

As is shown in FIG. 4, the supply of energy 14 takes place at a belt segment 20 inside carrier structure 11. Belt segment 20 at which the energy is fed in accomplishes the forwarding to other belt segments. The situation of element 14 takes place as shown in FIG. 10. On a rail 70 that is connected fixedly to carrier structure 11 inside the chain of belts, a linear guide 71 slides. A rotating feedthrough 72 that transfers the energy to endlessly rotatable element 73 is fastened to this linear guide. The rotating feedthrough is supplied with energy from energy chain 75, which is connected at the other end to carrier frame 11. In this element, in addition to the energies transmitted into 72, vacuum can be fed through as needed; for example, this vacuum can be used to fix the belts on 22 on the support. A traction element, for example a spring 77 between rail 74 and belt unit 20, is fastened to a rail 74. In addition, energy guide elements, for example hydraulic hoses and cables, are also fastened to rail 74.

If a belt segment 20 is now displaced, via the above-named traction element it exerts, in addition to the pre-tension force, an additional force on rail 74. In order to compensate the resulting imbalance of forces, elements 71 to 74 are displaced in such a way that an equilibrium is reestablished. In this way it is ensured that the supply of energy takes place in an ideal position at all times.

Alternatively, the supply of energy can also take place without linear guide 70, 71 and energy chain 75. In this case, the rotating feedthrough is situated centrically in carrier structure 11. Element 73 is realized as a drum from which a long energy chain leads to belt segment 20. Drum 73 is pre-tensioned with a constant moment by a suitable drive element, and provides that the energy chain from element 74 to element 20 is always under tension and does not make impermissible contact with the belts.

Carrier Structure

Carrier structure 11 is constructed in such a way that it can ideally accommodate the forces that arise, while at the same time enabling a supply of energy. FIG. 1 shows the arrangement of the carrier elements. Here, carrier segments 11a are fixed via connectors 11b. Braces 11c provide the necessary stability. The system has a modular construction and can be disassembled quickly, which facilitates mobile use.

FIG. 4 shows the carrier structure 11a front view without main drive chain 16 and belt segments 20. The loads that occur on the belt segments are accepted via elements 17 and 19. The cantilever of element 11a is kept as short as possible here. In addition, the greatest load occurs in the area of guide rails 19, which load is introduced directly into the stable perpendicular carriers of 11a. At the same time, due to the opening on the upper side of two connected elements 11a, sufficient space remains for the feedthrough of the energy chain.

The return routing of belt segments 20 takes place in the interior of carrier segments 11a.

Claims

1. A device having a surface displaceable in two spatial directions, comprising:

a carrier frame;

a conveyor means disposed such that it circulates on the carrier frame in a first direction;

a plurality of belt units,

each belt unit being fastenable to the conveyor means in such a way that it is displaceable in the first direction, and each belt unit comprising:

a first continuous belt that is disposed such that it circulates on the belt unit in a second direction; and a first driving roller for driving the first continuous belt in the second direction;

each first driving roller being actuated by a dedicated drive; and

each belt unit additionally has a second continuous belt that is situated on the belt unit parallel to the first continuous belt.

2. The device as recited in claim 1, characterized in that the second continuous belt is flatter and/or shorter than the first continuous belt.

3. The device as recited in claim 1, characterized in that each belt unit additionally has a second driving roller for driving the second continuous belt in the second direction.

4. The device as recited in claim 1, characterized in that the first and second continuous belt are drivable by the same driving roller.

5. The device as recited in claim 1, characterized in that the drives of the first driving rollers are connected in series.

6. The device as recited in claim 1, characterized in that the drives of the driving rollers comprise hydraulic motors and/or electric motors.

7. The device as recited in claim 1, characterized in that the carrier structure comprises a linear guide that is displaceable in the first direction and on which there is situated an endless rotating feedthrough for supplying energy to a drive, connected thereto, of a driving roller.

8. The device as recited in claim 7, characterized in that the carrier structure comprises a support structure for supporting the continuous belts of the belt units, such that a connection between the endless rotating feedthrough and the drive connected thereto in the second direction, approximately in the center of the appertaining belt unit, can circulate together with this belt unit in the first direction.

9. The device as recited in claim 1, characterized in that the conveyor means comprises two traveling chains that travel in the first direction, driven by at least one drive wheel per chain.

10. The device as recited in claim 9, characterized in that the run-in of each chain to the associated drive wheel has a guide surface for guiding the chain, comprising essentially two linear segments that are essentially parallel, two clothoidal segments, and a circular segment, in such a way that the chain goes from a first linear segment, in which it runs essentially in the first direction, with constant curvature into a first clothoidal segment, and from here goes with constant curvature into the circular segment, and then goes from here with constant curvature into the second clothoidal segment, and from this segment goes with constant curvature into the second linear segment.

11. The device as recited in claim 9, characterized in that each chain can be actuated by a first and second drive wheel, the first and/or second drive wheels of both chains each being controlled with angular synchronism.

12. The device as recited in claim 1, characterized in that at least one drive wheel is a polygonal wheel that can enter into positive engagement with bolts of the respective chain.

13. The device as recited in claim 1, characterized in that the second driving roller, together with the first driving roller, is made to travel by the drive of the belt unit in such a way that the first and second continuous belt have the same travel speed.

14. The device as recited in claim 1, characterized in that each belt unit has a traction means that pulls the continuous belt to a carrier structure of the belt unit.

15. The device as recited in claim 12, characterized in that the traction means comprises a magnet, in particular an electromagnet, and/or a vacuum device.