MOBILE STAND FOR AN OBJECT TO BE HELD

Description

[0001] The invention relates to a mobile stand for an object to be held, comprising a roller support with at least three rollers which are intended to roll on a surface so that the stand is mobile, a receptacle via which the object to be held can be coupled to the stand, a locking device with which the roller support can be locked in place relative to the surface, wherein the locking device is connected to an actuating device with which the locking device can be moved reversibly between a locked position and a released position,wherein the locking device comprises a pair or several pairs of elongated locking elements, and the locking elements of the or each pair can be pivoted in opposite directions from the rest position into the locking position by actuating the actuating device, and in the locking position are aligned obliquely and in opposite directions in contact with the ground.

[0002] A mobile stand is known, for example, from EP 1 571 277 A1 or from EP 2 565 350 A1.

[0003] The mobile stand known from EP 1 571 277 A1 offers high stability and robustness, while at the same time, the risk of injury is very low. The mobile stand is characterized by the fact that an actuating rod arranged on a lifting device causes a relative movement between a base and a roller support, whereby this movement changes the distance between the roller support and the base. To permanently position the mobile stand in a stationary position, the base is lowered onto a surface. In a driving position, the base is raised from the surface.

[0004] Such a mobile stand often has a high dead weight, which can be up to 150 kg. This high weight gives the mobile stand a stable footing. At the same time, however, it also affects the base, the lifting device and the roller support. When the roller support is raised, which leads to a simultaneous lowering of the base, high torques are generated on the lifting device due to the high weight. This can lead to the operating rod used to operate the lifting device, which also serves as a push rod for the stand, being accelerated towards a pole held by the stand, for example a parasol. If the operating rod is not always guided safely and with a certain amount of force, there is a risk that the operating rod slips out of the hand if the stand is handled improperly.

[0005] For this reason, the mobile stand known from EP 2 565 350 A1 comprises a force-assisting device, embodied, for example, in the form of a tension spring. Such a tension spring at least partially counteracts the pivoting movement of the actuating rod, or more precisely, the torque acting on the actuating rod. In other words, the torque acting on the actuating rod of the lifting device due to the high weight of the base is at least partially compensated by the force-assisting device used.

[0006] Both in the case of the mobile stand known from EP 1 571 277 A1 and in the case of the mobile stand known from EP 2 565 350 A1, a relatively large force must be applied to lift the base because the base has a relatively high weight.

[0007] Another mobile stand for an object to be held is known from EP 3 358 109 B1. This comprises a stand element for stationary installation of the stand on a surface in a standing position, a roller carrier with at least three rollers that are intended to roll along the surface in a traveling position so that the stand is mobile, a receptacle via which the object to be held can be coupled to the stand, and an actuating device with which the stand element can be moved between the standing position and the traveling position. In this mobile stand, the receptacle is attached to the roller carrier. This makes changing between the standing position and the traveling position of the mobile stand less strenuous than with the previously described mobile stands, since the weight of the object to be held does not also have to be lifted.

[0008] The mobile stands described above are used for stands with a weight of up to 150 kg. For stands heavier than this, the loads to be lifted become so great that this is no longer practical.

[0009] US 2018 / 0346008 A1 further discloses a mechanical ground stabilization system for caster-mounted vehicles, e.g., for a surgical assistance robot used in an operating room. The stabilization system includes pivoting support legs movable between a retracted position at a distance from the ground and a contact position that ensures the immobilization of the vehicle through mechanical friction against the ground.

[0010] FR 937 594 A discloses a device designed to prevent strollers or similar vehicles from tipping over when stopped. For this purpose, the vehicle is equipped with arms that extend forward and backward beyond the vehicle. These arms can be pivoted from a somewhat horizontal position to an inclined position in contact with the ground in front of and behind the vehicle to increase the effective length of the vehicle's support base.

[0011] Furthermore, JP S55 178457 U discloses a handcart for use on board aircraft or trains. The handcart has a braking mechanism that can be locked and unlocked manually. This mechanism acts on two brake arms that are pivotable and aligned in opposite directions.

[0012] Based on this prior art, it is an object of the present invention to provide a mobile stand for an object to be held, which on the one hand has a high stability due to its high weight, but on the other hand should also be easy and safe to use.

[0013] This object is achieved by a mobile stand for an object to be held, comprising a roller carrier with at least three rollers which are intended to roll on a surface so that the stand is mobile, a receptacle via which the object to be held can be coupled to the mobile stand, a locking device with which the roller carrier can be locked in place relative to the surface, wherein the locking device is connected to an actuating device with which the locking device can be moved reversibly between a rest position without contact with the surface and a locking position with contact with the surface,wherein the locking device comprises a pair or several pairs of elongate locking elements, and the locking elements of the or each pair can be pivoted in opposite directions from the rest position into the locking position by actuating the actuating device and, in the locking position, are oriented obliquely and in opposite directions in contact with the ground. The mobile stand is further developed in that the locking device comprises a tensile connection with at least one flexible tensile element, in particular a tensile cable, a tensile chain, or a tensile belt, which establishes a deflected tensile connection between the actuating device and the locking elements of at least one pair of locking elements, wherein the locking elements of the pair of locking elements are each spring-loaded in the opposite direction to a tensile load.

[0014] This solution offers the advantage of secure positioning while remaining extremely easy to operate. Unlike conventional mobile stands, the weight of the stand does not need to be lifted when switching from the stationary position to the mobile position. Instead, it rests, along with the weight of the object being held, on the rollers of the roller carrier, which are designed to support the corresponding total weight. Locking is achieved by pivoting the pair of elongated locking elements to the floor.

[0015] The special safety of this type of locking mechanism results from the combination of the locking elements being angled when in contact with the ground and the fact that the locking elements of each pair are aligned in opposite directions to each other. Because the locking elements are angled when in contact with the ground, they wedge into the ground if the mobile stand is moved in the opposite direction to the angle of the respective locking element. If the mobile stand is moved in the opposite direction, the wedge is released and the locking element offers no protection against rolling away. However, this protection is provided by the second locking element of the pair, whose alignment is opposite to that of the first locking element.

[0016] The mobile stand according to the invention further represents a particularly simple solution. In this case, the locking device comprises a tensile connection with at least one flexible tensile element, in particular a tensile cable, a tensile chain, or a tensile belt, which establishes a deflected tensile connection between the actuating device and the locking elements of at least one pair of locking elements, wherein the locking elements of the pair of locking elements are each spring-loaded in the opposite direction to a tensile load. This can be achieved, for example, by connecting the tensile element with its first end to a fastening point on the actuating device and with its second end directly or indirectly to a locking element, wherein the deflection occurs directly or indirectly at the other locking element of the pair of locking elements.

[0017] This corresponds to a simple cable pull. In the unloaded case, the locking elements are held in one position by tension springs, while a load on the tension element by movement of the actuating element causes the locking elements to deflect against the spring preload. In those embodiments in which the locking elements of a pair are oriented away from each other at the end facing the ground, the spring preload causes the locking elements to be preloaded outwards, i.e. they do not touch the ground, while a load on the tension element brings the locking elements into contact with the ground. In the opposite case, with the locking elements pointing towards each other at their lower ends, the spring preload draws them into contact with the ground, while the load on the tension element releases them from contact with the ground.In both cases, the tension springs are arranged in such a way that they move the locking elements away from each other, while a load on the tension element brings them closer together.

[0018] In addition to its simplicity, this solution has the further advantage of ensuring secure locking even on uneven surfaces.

[0019] This type of locking mechanism is also very effective against rotation of the mobile base if at least two pairs of locking elements, particularly aligned parallel to each other, are arranged on at least two sides of the mobile base. When the base rotates, two diagonally opposite locking elements then wedge into each other and prevent rotation. This makes the mobile base very suitable for heavy cantilever umbrellas whose center of gravity is not above the mobile base and which, in gusts of wind, tend to rotate around a vertical axis running through the mobile base.

[0020] Other effective configurations include a crosswise arrangement of two pairs that differ in orientation by, for example, 90°, or an arrangement of three pairs of locking elements in the shape of an equilateral triangle, for example. Secure locking can be achieved even if the configuration is not strictly symmetrical.

[0021] In some embodiments, the locking elements are each provided with a locking structure, in particular a tooth profile or anti-slip rubber attachment or covering, at their end that comes into contact with the ground.

[0022] In some embodiments, the locking elements are spring-loaded to hold them in contact with the surface in the locked position. This measure is advantageous for height adjustment on uneven surfaces, as it allows a greater degree of flexibility compared to a rigid mechanism.

[0023] In an alternative not according to the invention, the locking device comprises a control body rotatably mounted about a, in particular horizontal, axis of rotation, which is arranged between the locking elements of a pair and is connected to the actuating device in such a way that actuation of the actuating device leads to rotation of the control body about its axis of rotation, wherein the two locking elements of a pair are articulated by means of push and pull connections at articulation points of the control body that are opposite to one another relative to the axis of rotation. Due to the articulation at articulation points that are opposite to one another relative to the axis of rotation, an opposing movement results, which leads to an opposite pivoting direction for the two locking elements connected to the control body.

[0024] In a further development of the alternative not according to the invention, the push and pull connections of the locking elements to the control body are each designed as a combination of a spring-loaded connection and a rigid push connection, wherein the spring-loaded connection comprises a spiral spring, the first end of which is fastened to a fastening point on the control body or to a rigid part connected to the control body and the second end of which is fastened to the locking element at a fixed fastening point, and the rigid push connection comprises a rigid connecting rod, the first end of which is articulated on the control body and the second end of which is displaceably attached in an elongated hole in the locking element, which is aligned substantially in the direction of extension of the connecting rod.

[0025] When a locking element is pivoted from the rest position to the locked position, the coil spring pulls the locking element down as far as the stop of the rigid connecting rod in the slot allows. As soon as the locking element comes into contact with the ground, further retraction of the spring-loaded connection increases the tension on the coil spring, while the stop of the rigid connecting rod moves in the slot. In principle, this can continue until the stop of the rigid connection point reaches the near end of the slot. Conversely, when the locking element is pivoted from the locked position to the rest position, the spiral spring is first relieved by pushing the push and pull connection until the stop of the rigid connecting rod reaches the far end of the slot and from then on releases the locking element from contact with the ground and pushes it into the rest position.

[0026] To actuate the control body, in embodiments not according to the invention, it is hinged to the actuating device via a rigid connecting element. Thus, a pivoting movement or other movement of the actuating device can be converted into a rotational movement of the control body. A typical type of movement for the actuating device in such mobile stands is a pivoting movement, with a vertical orientation of the actuating device corresponding to the locked position and an angled orientation corresponding to the rest position.

[0027] In embodiments also not according to the invention, it is provided that a pivoting plane of the locking elements is aligned parallel to an orientation of a pivoting plane of the actuating device. Displacement of the mobile stand is usually achieved by pushing or pulling on the actuating device, so that aligning the pivoting planes of the locking elements in this direction leads to a particularly stable holding state.

[0028] In embodiments, the actuating device comprises an actuating element, in particular an actuating rod, which is pivotably mounted in a holding device connected to the roller carrier between a first end position and a second end position about a pivot axis of the actuating device, which correspond to the rest position and the locking position of the locking device, wherein the holding device is designed to counteract a movement of the actuating element from the first end position to the second end position and vice versa by a force that must be overcome. Typical end positions of such a pivotable actuating rod or actuating device are a vertical position and a significantly pivoted position, which can deviate from the vertical by, for example, but not by way of limitation, between 30° and 60°. This angular range is particularly suitable for handling the mobile stand.

[0029] For this purpose, embodiments provide that the actuating device has an elongated lever element on the side opposite the actuating element with respect to the pivot axis of the actuating device, at the end of which, with respect to the actuating element, a pivot point for one end of a prestressed spiral spring is arranged, the other end of which is provided with a sliding roller which, when the actuating element is pivoted from the first end position to the second end position, rolls on a sliding surface, in particular a planar one, of the holding device, which is arranged, in particular symmetrically, to the lever element in such a way that the spiral spring assumes a minimal extension or minimum extensions in each of the end positions and a maximum extension in a position between the end positions. This is a holding device that is mechanically very simple to implement.

[0030] In an alternative embodiment, it is provided that the actuating device has, on the side opposite the actuating element with respect to the pivot axis of the actuating device, an elongated lever element with two parallel legs running radially to the pivot axis of the actuating device, which has elongated holes running radially to the pivot axis of the actuating device, in which an axle pin aligned parallel to the pivot axis of the actuating device is displaceably mounted, which is connected via a preloaded spiral spring to a fastening point on or near the pivot axis of the actuating device, wherein the axle pin is equipped with two sliding rollers which roll on two similarly designed rolling guides of the holding device, which have minimal distances from the fastening point in the end positions and a maximum distance from the fastening point in a position between the end positions.This holding device, which is somewhat more complex to manufacture, offers even safer guidance than the previously described variant, as it allows fewer degrees of freedom of movement.

[0031] This is further enhanced if the rolling guides in certain embodiments have lateral limiting structures that prevent the sliding rollers from slipping sideways.

[0032] Furthermore, in embodiments, at least one weight is attached to the roller support, in particular detachably, attachable or fixed, so that the mobile stand can be made suitable for loads of different weights.

[0033] Further features of the invention will become apparent from the description of embodiments of the invention together with the claims and the accompanying drawings. Embodiments of the invention may fulfill individual features or a combination of several features.

[0034] Within the scope of the invention, features marked with "in particular" or "preferably" are to be understood as optional features.

[0035] The invention is described below, without limiting the general inventive concept, using exemplary embodiments with reference to the drawings, whereby express reference is made to the drawings for all details of the invention not explained in more detail in the text. They show: Fig. 1 a)-c) a non-inventive example of a mobile stand, Fig. 2 a), b) a second non-inventive example of a mobile stand, Fig. 3 details of a holding device of the second example, Fig. 4 details of a further holding device, Fig. 5 a lever element of a holding device according to Fig. 4 , Fig. 6the lever element from Fig. 5 with a spiral spring, Fig. 7 a principle drawing of a deflection mechanism with control body and Fig. 8 a principle drawing of a deflection mechanism according to the invention with a tension connection and a flexible tension element.

[0036] In the drawings, identical or similar elements and / or parts are provided with the same reference numbers, so that a repeated presentation is omitted.

[0037] Fig. 1 shows in partial images a) to c) a first example not according to the invention of a mobile stand 2, for example a mobile parasol stand, which stands on a base 8. The mobile stand 2 rests on rollers 6, which are rotatably attached to a roller carrier 4 of the mobile stand 2 and allow the mobile stand 2 to be moved and rotated in any direction. On the upper side of the roller carrier 4, a receptacle 10 for an object to be held, for example a parasol, is arranged, into which receptacle, for example, a pole of a parasol or another object can be inserted, or which can be provided with a corresponding holder.

[0038] The weight of the stand 2 and the object to be held rests on the rollers 6 in all situations. To prevent the mobile stand 2 from accidentally moving or rotating, a locking device 12 is provided. Furthermore, an actuating device 14, for example in the form of an actuating element 44, in this case an actuating rod, is provided for handling and actuating the locking device 12.

[0039] The locking device 12 has locking elements 16 in the form of pivotable feet, at the ends of which, in the illustrated embodiment, a locking structure 18, for example a rubber coating, is present, which acts as an anti-slip element when in contact with the base 8. The locking elements 16 can each pivot about horizontal pivot axes 19. The two locking elements 16 shown form a pair, within which the two locking elements 16 are pivoted in opposite directions to each other, i.e., toward or away from each other.

[0040] In Fig. 1 a) In the state shown, the locking elements 16 are not in contact with the substrate 18. In the Figuren 1 b) und c ), the locking elements 16 are pivoted further downwards and are in contact with the base 8. They are in an inclined position, with the two locking elements 16 of the pair being inclined in opposite directions. This means that in the event of a potential movement of the mobile stand 2 to the left, the Fig. 1 The locking element 16 shown on the left becomes wedged, while conversely, if the mobile stand 2 potentially moves to the right, the locking element 16 shown on the right becomes wedged. This means that the mobile stand 2 is secured against rolling away in both directions. With a suitable arrangement of two such pairs of locking elements 16 on two sides of the mobile stand 2, the latter is also secured against rotation, since in this case two diagonally opposite locking elements 16 become wedged against the base 8 and prevent this rotational movement.

[0041] While in the exemplary embodiment the Fig. 1 While it is shown that the two inclined locking elements 16 of the pair point away from each other, it is also possible that they are aligned towards each other.

[0042] The mechanism which leads from an actuation of the actuating device 14 to a pivoting of the locking elements 16 is shown in the three partial figures of the Fig. 1 The actuating device 14 is positioned between a vertical orientation ( Fig. 1 b), 1 c) ) and a tilted orientation ( Fig. 1 a) ), whereby a rigid connecting element 42 at the lower end of a lever element 54 of the actuating device 14 is displaced, which lever element is arranged below a pivot axis of the actuating device 14. The rigid connecting element 42 is articulated at its other end to a control body 20, which is rotated by the movement of the rigid connecting element 42 about a rotation axis 36 by an angle determined by the geometry of the lever ratios of the actuating device 14 and the control body 20. This angle is shown in the Fig. 1 indicated by a dashed line which runs through the axis of rotation 36 of the control body 20 and through the articulation point of the rigid connecting element 42 on the control body 20.

[0043] The control body 20 has two pivot points 38, 40, to which rigid connecting rods 30 are attached, each of which, in turn, is connected at its opposite end to one of the two locking elements 16 of the pair. The two pivot points 38, 40 are located on opposite sides of the control body 20 relative to its rotational axis 36. This creates an opposing movement of the two locking elements 16.

[0044] In order to enable pivoting of the locking elements 16 both for releasing and for establishing the locking, the connection between the control body 20 and each of the locking elements 16 is designed as a combined push and pull connection. In the illustrated embodiment of the Fig. 1 The tension connection is a spring-loaded connection 22, while the push connection is a rigid push connection with a slotted hole stop. Common to both connecting parts is the rigid connecting rod 30, which each engages one of the two articulation points 38, 40 of the control body 20. At one point on the rigid connecting rod 30 there is an attachment point 28 for a spiral spring 24. The opposite attachment point 26 is located on the respective locking element 16. This spring connection allows the control body 20 to continue rotating once the locking element 16 has already come into contact with the base 8. Further rotation of the control body then leads to tension in the spiral spring 24. Since the rigid connecting rod 30 is attached to the locking element 16 in a long hole 34, this rigid part of the connection has a certain amount of play.When the control body 20 is rotated in the opposite direction, the rigid connecting rod 30 is moved in the opposite direction. At the beginning of this movement, the coil spring 24 is relieved, and the stop of the rigid connecting point 30 slides in the elongated hole 34 toward its opposite end. The locking element 16 does not move during this phase. At the moment the stop of the rigid connecting point 30 in the elongated hole 34 reaches its end, any further outward movement of the rigid connecting rod 30 will cause the locking element 16 to be released from the base 8 and twisted upwards away from it.

[0045] In Fig. 1 c) shows how such a flexible mechanism also copes with an uneven surface 8. The surface 8 is flat at the location of the locking element 16 shown on the left, while at the location of the locking element 16 shown on the right (in the area of ​​the ellipse) it has an unevenness in the form of a depression. In this case, the right-hand locking element 16 moves further into the depression before coming into contact with the surface. The combination of spring-loaded connection and rigid push-fit connection with elongated hole enables this different alignment of the locking elements 16 with simultaneous identical actuation via the common control body 20. The different angle of inclination is indicated in this area by two dashed lines.

[0046] In Fig. 2 a) is the locked position and in Fig. 2 b) The mobile position of a second non-inventive example of a mobile stand 2 is shown, which differs in some details from the first examples. Thus, the push and pull connection between the control body 20 and the locking elements 16 is completely rigid, and the actuating mechanism is also designed somewhat differently. This is shown in Fig. 3 in more detail a corresponding holding device 46' is shown, namely in a locked end position 40 with vertical alignment of the actuating device 14 (left part of the image), in an intermediate position (middle part of the image) and in an end position 48 with the locking released and the actuating device 14 in an inclined position (right part of the image).

[0047] In this example not according to the invention, the actuating device 14 is also pivotally connected via a pivot axis 52 to a lever element 54 located below the pivot axis 52. At its lower end, the lever element 54 is pivotally connected to a rigid connecting element 42 at a pivot point 56. Also attached to the pivot point 56 is a spiral spring 58 that is oriented upwards and ends with a sliding roller 60 that rests on and rolls on a flat sliding surface 62 or rolling surface. The lever element 54 is angled relative to the actuating element 44 or the actuating device 14 in such a way that the pivot point 56 is arranged to the left and right of the vertical below the pivot axis 52 in the two end positions 48, 50.Since the pivot point 56 moves along a circumference around the pivot axis 52 during pivoting, the distance between the pivot point 56 and the sliding surface 60 is minimal in these two end positions 48, 50, while the distance is greater in the intermediate position. This difference is shown in . Fig. 3 marked with an X between two dashed lines. In the intermediate position, the deflection of the coil spring 54 is therefore greater than in the end positions 48, 50. Therefore, a spring force must be overcome to move from one end position to the other. This stabilizes the mechanism in the two end positions 48, 50 while simultaneously requiring minimal design effort. For safe operation, care should be taken to ensure that the sliding surface 62 is flat and the sliding roller 60 runs smoothly.

[0048] At the same time, care must be taken to ensure that there is a sufficient distance Y between the pivot axis 52 and the axis of the sliding roller 60 so that the latter can move under the pivot axis.

[0049] In Fig. 4 an alternative example of a holding device 46 is shown, not according to the invention, in an oblique perspective from above (top row) or from below (bottom row), and, running from left to right, in the locked end position 50, an intermediate position and the released end position 48.

[0050] The holding device 46 comprises a housing which has eyes or receptacles for the swing axis 52 of the actuating device 14, as well as curved rolling guides 74 at the lower end. As can be seen particularly in the lower row of the Fig. 4 As can be seen, sliding rollers 72 run on these rolling guides 74, which are held in a two-legged lever element 54' in two parallel, vertically aligned slots 64. The lever element 54' with the two legs 66 is in Fig. 5 better seen in perspective, as well as a through hole for the swing axis 52 and the elongated holes 64, which are aligned radially outwards with respect to the pivot axis 42.

[0051] Also in Fig. 5 a fastening point 70 is shown, the function of which is shown in the Fig. 6 becomes clear. Thus, between the legs 66 of the lever element 54', a spiral spring 58 is arranged, which is held by two axle pins 68, 69, on the one hand stationary at the attachment point 70 and on the other hand radially displaceable in the elongated holes 64. The spiral spring 58 is preloaded. The axle pin 68 projecting through the elongated holes 64 is provided outside the two legs 66 with sliding rollers 60, which, as in Fig. 4 shown, roll on the rolling guides 74 of the holding device.

[0052] In the two end positions 48, 50, the sliding rollers 60 move within the elongated holes 64 towards the pivot axis 52 due to the recessed shape of the rolling guides 74, thereby relieving the load on the coil spring 58. Between the two end positions 48, 50, the rolling guides 74 have a downwardly bulging section, which causes the coil spring 58 to stretch. The coil spring 58 counteracts this with its spring force, so that pivoting of the actuating element or actuating device 14 is only possible against the spring force. This holds the mechanism in the end positions 48, 50. Due to the design with the elongated holes 64, this mechanism only has the degree of freedom of movement of pivoting around the pivot axis 52, so that well-defined end positions 48, 50 are present.In addition, the rolling guides 74 are bent beyond the end positions 48, 50 in such a way that further pivoting is prevented by the sliding rollers 60 hitting the end contours of the rolling guides 74, beyond which they cannot be moved.

[0053] The rolling backdrops 74 have in the Fig. 4 shown form also lateral limiting structures 76, which represent a lateral guide for the sliding rollers 60 and thus prevent them from slipping sideways.

[0054] In the Fig. 4 In the form shown, the rolling guides 74 are designed symmetrically with respect to the end positions 48, 50. This is not mandatory, since in other embodiments it may be desirable, for example, to oppose a greater force with respect to one end position than with the other end position. For example, it may be desirable for the force required to leave the locking position to be greater than the force required to leave the mobile position. In this case, the rolling guides 74 are designed asymmetrically, with a steeper incline to be overcome on the side of the end position 50, in which the locking device is brought into the locking position, than in the other end position 48.

[0055] Fig. 7 is a schematic drawing of a deflection mechanism not according to the invention with a control body 20, which essentially corresponds to the embodiments of the Figuren 1 and 2The upper illustration is a top view, while the two lower illustrations are side views in various pivoting positions. It is clear that the pivot bearing 15 of the actuating device 14 is a stationary bearing, as are the pivot axes 19 of the locking elements 16 and the rotation axis 36 of the control body 20. Any pivoting movement of the actuating device 14 is converted into opposing pivoting movements of the locking elements 16 via the rigid deflection mechanism with the control body 20 via connecting rods.

[0056] In Fig. 7 It is also shown that two locking elements 16 are connected to each other via a connecting rod 17, so that the two pairs of locking elements 16 are moved together. The rigid connecting rods are doubled to increase the stability and balance of the mechanism, with the exception of the connecting rod that connects the lower end of the actuating device 14 to the upper pivot point 38 of the control body 20.

[0057] Fig. 8 is a schematic drawing of a deflection mechanism according to the invention with a tension connection and a flexible tension element 80. Just as in Fig. 7 Here, too, the upper illustration is a top view, while the two lower illustrations are side views in different pivoting positions. In this embodiment, too, the locking elements 16 of different pairs of locking elements 16 are connected to one another via connecting rods 17.

[0058] The flexible tension element 80, for example a tension cable, is connected with a first end, here exemplary in the form of a loop, to a first attachment point 82 of the actuating device 14. When the actuating device 14 pivots about the pivot bearing 15, the attachment point 82 moves in the opposite direction. The flexible tension element 80 is deflected via a deflection, which in this case is exemplary arranged on the connecting rod of the locking elements 16 shown on the left, and then leads with its second end, again in the form of a loop, to a second attachment point 84 on the connecting rod 17 between the other two locking elements 16. The pulling movement is thus transmitted to the locking elements 16 via the connecting rods 17. Alternatively, the tension element 80 can also act directly on the locking elements 16, or more than one tension element 80 can be provided.

[0059] As the two lower partial drawings illustrate, when the actuating element 14 is in a vertical position, the tension connection with the tension element 80 is tensioned, and the opposing locking elements 16 are moved toward or tensioned against each other. Pivoting the actuating element 14 loosens the tension connection and releases the locking elements 16. Since these are pretensioned by tension springs 88 against the pulling direction, the locking elements 16 are pulled out of contact with the ground and away from each other.

[0060] In addition to its simplicity, this embodiment of the invention with the tensile connection has the further advantage that it inherently compensates for uneven floors.

[0061] All mentioned features, including those that can be inferred from the drawings alone, as well as individual features disclosed in combination with other features, are considered essential to the invention, both individually and in combination. Embodiments according to the invention may be fulfilled by individual features or a combination of several features. Bezugszeichenliste

[0062] 2 mobile stand 4 roller carrier 6 rollers 8 base 10 support 12 locking device 14 actuating device 15 pivot bearing 16 locking element 17 connecting rod 18 locking structure 19 pivot axis 20 control body 22 spring connection 24 coil spring 26, 28 attachment point 30 rigid connecting rod 32 rigid push connection 34 slotted hole 36 rotation axis of the control body 38, 40 articulation point 42 rigid connecting element 44 actuating element 46, 46 holding device 48, 50 end position 52 pivot axis of the actuating device 54 lever element 56 articulation point 58 coil spring 60 sliding roller 62 sliding surface 64 slotted hole 66 leg 68, 69 axle pin 70Attachment point 72Sliding roller 74Rolling gate 76Lateral boundary structure 80Tension element 82First attachment point 84Second attachment point 86Deflection 88Tension spring

Claims

1. Mobile stand (2) for an object to be held, comprising a roller carrier (4) with at least three rollers (6) designed to roll on a ground surface (8) so that the stand (2) is mobile, a mount (10) via which the object to be held can be coupled to the mobile stand (2), a locking device (12) by means of which the roller carrier (4) can be locked in position relative to the ground surface (8), the locking device (12) being connected to an operating device (14) by means of which the locking device (12) can be moved reversibly between a rest position without contact with the ground surface and a locking position with contact with the ground surface, wherein the locking device (12) has one pair or several pairs of elongated locking elements (16) and the locking elements (16) of the or each pair can be pivoted in opposite directions relative to each other from the rest position into the locking position by operating the operating device (14) and, in the locking position, in contact with the ground surface, are oriented obliquely and in opposite directions relative to each other, characterised in that the locking device (12) comprises a pull connection with at least one flexible pull element (80), in particular a pull cable, a pull chain or a pull strap, which establishes a deflected pull connection between the operating device (14) and the locking elements (16) of at least one pair of locking elements (16), wherein the locking elements (16) of the pair of locking elements (16) are each spring-biased in the opposite direction to a pull load.

2. Mobile stand (2) according to claim 1, characterised in that the flexible pull element (80) is a pull cable, a pull chain or a pull strap.

3. Mobile stand (2) according to claim 1 or 2, characterised in that at least two pairs of locking elements (16), in particular aligned parallel to each other, are arranged on at least two sides of the mobile stand (2).

4. Mobile stand (2) according to one of claims 1 to 3, characterised in that the locking elements (16) are each provided at their end coming into contact with the ground surface (8) with a locking structure (18), in particular a tooth profile or anti-slip rubber attachment or covering.

5. Mobile stand (2) according to any of claims 1 to 4, characterised in that, in the locking position, the locking elements (16) are held in contact with the ground surface (8) by spring bias.

6. Mobile stand according to one of claims 1 to 5, characterised in that a pivot plane of the locking elements (16) is aligned parallel to an orientation of a pivot plane of the operating device (14).

7. Mobile stand (2) according to any of claims 1 to 6, characterised in that the operating device (14) comprises an operating element (44), in particular an operating lever, which is mounted in a holding device (46, 46') connected to the roller carrier (4) so as to be pivotable about a pivot axis (52) of the operating device (14) between a first end position (48) and a second end position (50), which correspond to the rest position and the locking position of the locking device (12), wherein the holding device (46, 46') is designed to exert a force to be overcome against a movement of the actuating element (44) from the first end position (48) to the second end position (50) and vice versa.

8. Mobile stand (2) according to claim 7, characterised in that the operating device (14) has a longitudinally extended lever element (54) on the side opposite the operating element (44) with respect to the pivot axis (52) of the operating device (14), at the far end of which, relative to the actuating element (44), there is arranged a link point (56) for one end of a preloaded spiral spring (58), the other end of which is provided with a sliding roller (60) which, when the operating element (44) is pivoted from the first end position (48) to the second end position (50), rolls off a sliding surface (62) of the holding device (46'), which is arranged in such a way, in particular symmetrically, relative to the lever element (54) in its two end positions (48, 50) that the spiral spring (58) assumes a minimum extension or, respectively, minimal extensions in the end positions (48, 50) and a maximum extension in a position between the end positions (48, 50).

9. Mobile stand (2) according to claim 8, characterised in that the operating device (14) has, on the side opposite the operating element (44) with respect to the pivot axis (52) of the operating device (14), an elongated lever element (54') with two parallel legs (66) extending radially to the pivot axis (52) of the operating device (14), which has elongated holes (64) extending radially to the pivot axis (52) of the operating device (14), in which an axle pin (68) aligned parallel to the pivot axis (52) of the operating device (14) is slidably mounted, which is connected via a preloaded spiral spring (58) to a fixing point (70) on or near the pivot axis (52) of the operating device (14), wherein the axle pin (68) is equipped with two sliding rollers (72) which roll on two identically designed roller guides (74) of the holding device (46), which at the end positions (48, 50) have minimum distances and, in a position between the end positions (48, 50), have a maximum distance to the fixing point (70).

10. Mobile stand (2) according to claim 9, characterised in that the roller guides (74) have lateral limiting structures (76) which prevent the sliding rollers (60) from slipping sideways.

11. Mobile stand (2) according to any of claims 1 to 10, characterised in that at least one weight can be attached or is attached to the roller carrier (4), in particular in a releasable manner.