Expanding mechanism for a tensionable device and tensionable device

Abstract

The invention relates to a spreading mechanism (30) for a clampable device (10) and to a clampable device (10) which comprises a standpipe (12) and a clampable support frame (14) with a plurality of pairs of support arms (16) which diverge in a star shape and support struts (18) which are articulated to the support arms (16), wherein the support arms (16) are articulated to a first central support (20) and the support struts (18) are articulated to a second central support (22), and the spreading mechanism (30) is designed to clamp or close the support frame (14) by reducing or increasing the distance between the first central support (20) and the second central support (22).The spreading mechanism (30) comprises an actuating mechanism (50) and a pulley block (32) with a pulley cable (40), a fixedly attached first roller holder (34) and a movable second roller holder (36), each with one or more rollers (38) over which the pulley cable (40) is guided, wherein the actuating mechanism (50) is connected to the movable second roller holder (36) of the pulley block (32) and a fast end (42) of the pulley cable acts in a displacing manner on the first central holder (20) and / or the second central holder (22) in order to change their distance from one another.

Description

[0001] The invention relates to a spreading mechanism for a tensionable device, such as a standing umbrella or a rotary clothes dryer, as well as a tensionable device

[0002] Rotary clotheslines and free-standing umbrellas, both center-pole and side-arm umbrellas, have very similar extendable support structures. Center-pole umbrellas and rotary clotheslines are particularly similar in that they each have a number of support arms, each pivoted centrally to a support device on the central pole or upright, as well as an equal number of support struts pivoted to the support arms and pivoted toward the center to another support device on the central upright. In the case of free-standing umbrellas, the support arms carry a canopy made of fabric or another flexible flat material, and in the case of rotary clotheslines, they carry the clotheslines.

[0003] The configuration of the support arms and struts differs between free-standing umbrellas and rotary clotheslines in that, with free-standing umbrellas, the support arms are usually attached to a bracket at the top of the standpipe, also called a "crown," which is fixed to the upper end of the standpipe. The support struts are attached to a second bracket below, which can be moved vertically along the standpipe. This bracket is also called a race or sliding sleeve. In contrast, with rotary clotheslines, the support struts are usually attached to the upper, fixed bracket, and the support arms are attached to the lower, vertically movable bracket.

[0004] In both cases, the extendable support frame is opened by pushing the lower support bracket upwards, which reduces the distance between the two support brackets and moves the support arms into an extended position. The support arms are tilted downwards for parasols and upwards for rotary clotheslines.

[0005] The principle is very similar for side-arm umbrellas. However, the support brackets are not attached directly to the standpipe. Instead, a side arm branches off from the standpipe, or a curved standpipe is used, from the tip of which a lateral mechanism extends, allowing the distance between the two support brackets to be adjusted.

[0006] Finally, there are also combinations of standing umbrellas and rotary clotheslines on the market, where the umbrella is mounted above the clotheslines and both parts are tensioned with a mechanism, as known, for example, from DE 10 2008 052 049 A1 or from EP 3 070 198 B1.

[0007] Various spreading mechanisms are in use and known for rotary clotheslines and standing umbrellas. While handheld umbrellas and small parasols require the axially adjustable sliding sleeve to be manually moved until it locks into place, rotary clotheslines or larger standing umbrellas use hand-operated ropes or crank-operated ropes, for example.

[0008] There are also electric drives or pulley blocks. These are used, for example, in rotary clothes dryers. The end of the pulley cable extends out of the standpipe in which the pulley is located. A large length of the pulley cable is pulled out to push the lower holding device, which is connected to a movable pulley holder of the pulley, up the standpipe by a smaller amount, thereby tensioning the rotary clothes dryer's support frame. This is often combined with a retrieval device for the long end of the pulley cable, which is retracted into the standpipe as soon as the long pulley cable is released.

[0009] Particularly at the end of the setup process, a strong lateral pull is exerted on the rotary clothesline's standpipe, so it needs to be firmly anchored in the ground or have a very stable stand to prevent the rotary clothesline from tipping over. The same applies to pulley-operated umbrellas.

[0010] Compared to the known spreading mechanisms and clampable devices, the object of the present invention is to provide a spreading mechanism and a clampable device with which the supporting structure can be clamped with little physical effort.

[0011] This object is achieved by a spreading mechanism for a clampable device, which comprises a standpipe and a clampable support frame with several pairs of support arms extending apart in a star shape and support struts articulated to the support arms, wherein the support arms are articulated to a first central support and the support struts are articulated to a second central support and the spreading mechanism is designed to open or close the support frame by reducing or increasing the distance between the first central support and the second central support, which is further developed in that the spreading mechanism comprises an actuating mechanism and a pulley block with a pulley cable, a fixedly attached first roller holder and a movable second roller holder, each with one or more rollers over which the pulley cable is guided,wherein the actuating mechanism is connected to the movable second roller holder of the pulley block and a fast end of the pulley cable acts on the first central support and / or the second central support in a displacing manner in order to change their distance from one another.

[0012] The invention is based on the basic idea of using a pulley block in the opposite direction to usual for spreading the support structure. The fast end of the pulley block, i.e. the end of the pulley rope that moves quickly and over a long distance, is no longer used to operate the pulley block, but is connected to the movable second pulley holder, i.e. the sliding sleeve, while the slow end of the pulley block, i.e. a movable pulley holder of the pulley block, is subjected to a greater force and a smaller design. This is counterintuitive because the force required to the pulley block is greater than the force required to clamp the support structure itself. This is compensated for by the actuating mechanism, which is connected to the movable second pulley holder. This actuating mechanism is preferably designed to exert a large force with a small deflection.

[0013] The gear ratio of a pulley block is defined by the number of rope sections of the pulley block rope running between the two pulley holders and is, in some designs, between 2:1 and 10:1, preferably between 4:1 and 8:1. This includes both even-numbered and odd-numbered gear ratios.

[0014] In some embodiments, the pulley is arranged inside the standpipe.

[0015] Advantageously, the spreading mechanism comprises a force-assisting device configured to permanently exert a force on the movable second roller holder of the pulley block, directed in the direction of tensioning the supporting structure. This supporting force then no longer needs to be applied by means of the actuating mechanism, thus facilitating tensioning of the supporting structure. The supporting force applied by the supporting device should preferably be dimensioned such that it supports tensioning but does not prevent tensioning, which is typically assisted by gravity.

[0016] In some embodiments, the force-assisting device is designed as a spring device with a spring or a combination of springs, in particular a coil spring, gas pressure spring, and / or gas tension spring, and / or a weight. These can be accommodated in the standpipe of the device. A coil spring can be used as a tension spring or as a compression spring, with deflection in a tension spring representing an extension of the spring and in a compression spring representing compression.

[0017] While a weight as a force-assisting device provides a constant force regardless of position, the force provided by a spring depends on its deflection. The more a spring is deflected, i.e. stretched or compressed, the greater the restoring force exerted by the spring. Since a spring as a force-assisting device, regardless of whether it is used as a tension spring or a compression spring, relaxes when supporting the clamping of the support frame of the device and tensions again when unclamping, the supporting force at the end of the clamping process is smaller than at the beginning. At the same time, the spring force near the unclamped end position, i.e. where it reaches its maximum, must not be so great that the support frame cannot be folded shut.

[0018] In this context, when using a spring or combination of springs as a force assistance device, embodiments provide for a spring characteristic curve of the spring device to be linear, degressive, or progressive. A degressive characteristic curve is understood to be a spring characteristic that increases less than linearly with increasing deflection. In other words, a degressive spring characteristic describes a spring that becomes softer with increasing load and harder with decreasing load. This means that the support remains comparatively large even with decreasing deflection, i.e. decreasing load, in order to be able to continue supporting the clamping process. Preferably, the spring should still have sufficient deflection even in the clamped position of the support frame. This ensures sufficient restoring force even in the more relaxed of the two end states.A progressive spring characteristic, on the other hand, describes a spring that becomes harder with increasing load and softer with decreasing load. In other embodiments, the spring device is provided in combination with a weight.

[0019] In some embodiments, the actuating mechanism is connected to the movable second pulley holder of the pulley block in a tensile-resistant manner. In some embodiments, this is achieved by connecting the actuating mechanism to the movable second pulley holder of the pulley block via a pull rope, a pull chain, or a rigid pull-push rod. The latter embodiment, with the rigid pull-push rod, has the additional function that a force can also be exerted on the pulley block via the actuating mechanism to assist in guying.

[0020] In some embodiments, the operating mechanism is designed as a lever, electric winch, manual pull rope, hand crank, foot pedal, or hand lever for a pull rope, or as a hand lever for a rigid pull-push rod. Depending on the design of the operating mechanism, the gear ratio of the pulley block can be selected to match the force exerted by the operating mechanism. For example, a hand pull rope allows for a comparatively low force to be exerted, which can be compensated for by a low gear ratio. A hand crank, foot pedal, or hand lever, with a sufficiently long lever arm or crank arm, allows for significantly greater force development, so the gear ratio of the pulley block can also be selected accordingly.

[0021] Furthermore, a locking device for the actuating mechanism can be included, or the actuating mechanism can be self-locking. Alternatively, the support frame itself can also be designed with a locking device that holds the support frame in the clamped state.

[0022] In an embodiment in which the actuating mechanism is self-locking, the lever of the actuating mechanism has a short lever arm and a long lever arm, wherein the short lever arm is connected at one end to the movable second roller holder of the pulley block and is pivotally connected at its other end to the long lever arm, wherein the long lever arm is pivotally attached to the standpipe about a horizontal axis of rotation at a first distance from the connection to the short lever arm, wherein the first distance and a second distance of the horizontal axis of rotation from the standpipe are selected such thatthat when the clampable support structure is opened by pivoting the long lever arm from a downward-facing end position to an upward-facing end position, the end of the short lever arm connected to the movable second roller holder of the pulley block passes through a low point and, upon reaching the upward-facing end position of the long lever arm, assumes an end position above the low point.

[0023] The self-locking mechanism is based on the fact that, in the end position, the second pulley holder of the pulley block is not at a low point, but positioned slightly above it. It requires considerable force to move it back down to the low point and beyond, which gives the operating mechanism a strong tendency to remain in its end position. This can be supported, if necessary, by a clamping mechanism that clamps and, if necessary, fixes the long lever arm in its upward-pointing end position.

[0024] The object underlying the invention is also achieved by a clampable device with a standpipe and a clampable support frame with several pairs of support arms which extend apart in a star shape and support struts which are articulated on the support arms, wherein the support arms are articulated on a first central support and the support struts are articulated on a second central support, as well as a spreading mechanism which is designed to open or close the support frame by reducing or increasing the distance between the first central support and the second central support, in which the spreading mechanism is designed according to the invention as described above.

[0025] The clampable device thus realizes the same advantages, properties and features as the spreading mechanism according to the invention.

[0026] In embodiments, the expandable device is designed as a standing umbrella, in particular a center mast umbrella or side arm umbrella, as a rotary clothes dryer or as a combination of a rotary clothes dryer and a center mast umbrella.

[0027] 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 incorporate individual features or a combination of several features.

[0028] Within the scope of the invention, features marked with "in particular" or "preferably" are to be understood as optional features.

[0029] 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 schematic representation of a standing umbrella in the closed and open state, Fig. 2 a schematic representation of an embodiment of a spreading mechanism according to the invention, Fig. 3 schematic representations of two embodiments of spreading mechanisms according to the invention, Fig. 4 schematic representations of embodiments of spreading mechanisms with different actuating mechanisms and Fig. 5 schematic representation of the functioning of an embodiment of a spreading mechanism with a self-locking actuating mechanism.

[0030] In the drawings, identical or similar elements and / or parts are provided with the same reference numbers, so that a repeated presentation is omitted.

[0031] Fig. 1 shows a schematic representation of a standing umbrella as an example of an extendable device 10 in the closed and open state. The standing umbrella has a standpipe 12, also referred to as a mast, which (not shown) can be anchored to the ground or erected with a stable base. At its upper end, the standing umbrella carries a support frame 14 with a plurality of support arms 16, each of which is articulated to a support strut 18. The support arms 16, on which an umbrella support 17 rests, converge centrally at a first central bracket 20, also called the crown, where they are suspended in an articulated manner. Approximately in the middle of the support arms 16 are articulated connections to the support struts 18, which in turn run from the support arms 16 towards the standpipe 12, where they are articulated to a movable second central bracket 22, which is also referred to as a sliding sleeve or similar.

[0032] In the folded state shown on the left, the support arms 16 hang essentially vertically from the first central bracket 20, which is firmly connected to the upper end of the standpipe 12, as do the support struts 18. The distance between the first central bracket 20 and the movable second central bracket 22 is maximum in this state. In the unfolded state shown on the right, the support arms 16 point apart, but retain an extended angle typical for standing umbrellas. The support arms 16 are held in the glued position by the support struts 36. For this purpose, the second central bracket 22 has been moved from its lower position to an upper position by a vertical stroke S2.

[0033] In Fig. 1 In the upper region of the standpipe 12, a spreading mechanism 30 with a pulley 32 according to the present invention is also shown. The pulley 32 comprises a fixedly suspended first roller holder 34 and, below it, a movable second roller holder 36, each with a plurality of rollers 38. A pulley rope 40 runs, wound several times, over the plurality of rollers 38 on the first roller holder 34 and the second roller holder 36, which Fig. 2 is clearly visible. The pulley rope 40 is connected with its fast end 42 to the movable second central support 42. The pulley 32 is articulated such that a vertical displacement of the movable second roller holder 36 by a stroke S1 is converted into an opposite stroke S2 of the fast end 42 of the pulley rope 40. In the embodiment of the Fig. 1 As in the following exemplary embodiments, the transmission ratio of the sections S2 to S1 is selected as 8:1. Conversely, the transmission ratio also applies to the force required to clamp the supporting frame 14, which is thus increased eightfold.

[0034] Fig. 2 is a schematic representation of an embodiment of a spreading mechanism according to the invention according to Fig. 1 in more detail. It can be seen that the pulley block 32 is suspended with its upper first pulley holder 34 from an upper suspension 33, while the lower second pulley holder 36 is freely movable relative to the first pulley holder 34. Both pulley holders 34, 36 each hold four pulleys 38 of different circumferences, around which the pulley cable 40 is wound in a manner typical of a pulley block. The number of sections of the pulley cable 40 between the first pulley holder 34 and the second pulley holder 36 is eight and determines the gear ratio 8:1 of the pulley block 32. For this purpose, the pulley cable 40 is attached at one end to an upper attachment point 35, which coincides with the axis of the lowest pulley 38 of the first pulley holder 34. The pulley rope 40 is then guided four times downwards to a roller 38 of the second roller holder 36 and again upwards to a roller 38 of the first roller holder 34.After the last guide of the pulley rope 40 upwards, the pulley rope 34 is guided into the upper suspension 33 and from there via a deflection pulley 39 outwards and downwards to the displaceable second central bracket 22.

[0035] The lower second roller holder 36 also has a lower stop point 37 to which a force is applied that can be applied by an actuating device of the spreading mechanism. As also shown in Fig. 2 As indicated, the transmission ratio of 8:1 for the pulley block 32 means that a stroke S1 of the second roller holder 36 is converted into a counter-rotating stroke S2 of the second center bracket 22. The stroke S2 is eight times the magnitude of the stroke S1. Conversely, the force F2 on the second center bracket 42 is only one-eighth of the force F1 exerted on the second roller holder 36.

[0036] Fig. 3 shows schematic representations of two embodiments of spreading mechanisms according to the invention, both of which have different force support devices 90, which are each connected, for example suspended, to the lower attachment point 37 with the movable second roller holder 36 of the pulley 32. In the left illustration of the Fig. 3 is a spiral spring 92, which is connected at its upper end to the second roller holder 36 and at its lower end to a spiral spring stop 93 on the standpipe 12. In this configuration, the spiral spring 92 is a tension spring.

[0037] In the right half of the picture Fig. 3 An embodiment is shown in which the force-assisting device 90 is a weight 94 attached to the lower attachment point 37 on the second roller holder 36. The weight 94 pulls the second roller holder 36 downward with a constant weight force. With the transmission ratio of 8:1 unchanged from the previous starting examples, one-eighth of the weight force exerted by the weight 94 is applied to the second central bracket 22 and is available to assist in unfolding the support frame 14. The foot pedal 66 can also be provided with a locking device 80.

[0038] In the fourth example of the Fig. 4 The actuating mechanism 50 comprises a hand lever 68, to which the traction cable 52 is attached, approximately one third of its length from a joint on the standpipe 12 to the open end of the hand lever 68. The Fig. 4 The supporting frame 14 (not shown) is clamped by moving the hand lever 68 from its downward position, which is shown in Fig. 4 shown, is brought into an upper position. Due to the leverage effect, the movement of the outer end of the hand lever 68 is transmitted to the second roller holder 36 with a transmission ratio of approximately 3:1.

[0039] Fig. 4 shows several schematic representations of embodiments of spreading mechanisms with different actuation mechanisms. In all illustrated embodiments, a force-assisting device 90 in the form of a spiral spring 92 according to the left figure in Fig. 3 available.

[0040] The embodiments of the Fig. 4 differ in the actuating mechanisms 50. In the first embodiment, from left to right, the actuating mechanism 50 comprises a hand crank 64 around which a traction cable 52 is wound. Depending on the length of the crank arm of the hand crank 64, the spreading mechanism 30 can be operated with reasonably little effort to clamp the support frame 14. The hand crank 64 can be equipped with a locking mechanism and / or be self-locking.

[0041] The second embodiment comprises a hand pulley 62 deflected around a deflection pulley 63 and a hook 65 around which a loop of the hand pulley 62 can be placed. The deflection pulley 63 makes it possible to pull the loop of the hand pulley 62 from bottom to top with a favorable lever, thus exerting a force on the second pulley holder 36 at a more favorable angle of attack. If the deflection pulley 63 is arranged close to the ground, even when pulled sideways, only a small tilting moment is exerted on the device due to the short lever arm to the ground. Because no force transmission occurs, this type of actuating mechanism 50 is particularly suitable for smaller transmission ratios of the pulley block 32. For locking purposes, a further hook 65 for the loop of the hand pulley 62 can be provided, for example, further up on the standpipe 12.

[0042] The one in the middle in Fig. 4 The embodiment shown has a foot pedal 66 that is pivotally fixed at a pivot point 67. Approximately in the middle of the longitudinal extent of the foot pedal 66, a pull cable 52 or a rigid pull-push rod 54 is connected to the foot pedal 66, which pulls the second roller holder 36 downward when the foot pedal 66 is pressed. The lever ratios on the foot pedal 66 result in a transmission ratio of 2:1, which in this case means that the stroke of the open end of the foot pedal 66 is halved when transferred to the second roller holder 36 and the applied force is doubled.

[0043] The Fig. 4 The embodiment shown on the far right is also based on the use of a hand lever 70, which, however, is provided with a self-locking mechanism. This is shown in Fig. 5 schematically shown in its function from a closed position (left) to an open and locked position (right).

[0044] In this embodiment, the hand lever 70 comprises a long lever arm 74 with a handle 75 and a short lever arm 72, which is pivotally connected to the long lever arm 74 and represents a connection between the long lever arm 74 and a rigid pull-push rod 54 inside the standpipe 12, which forms the lever arm 70 with the lower stop point 37 of the second roller holder 36, as shown for example in Fig. 2 is shown. A joint 73 forms the connection between the short lever arm 72 and the pull-push rod 54. The long lever arm 74 is pivotable relative to the standpipe 12 about a horizontal joint axis 76, which is suspended from a stop body 78 attached to the outside of the standpipe 12.

[0045] Links in Fig. 5 is the starting point for setting up the Fig. 5 The long lever arm 74 points horizontally downwards. Slightly above the horizontal axis of rotation 76 of the long lever arm 74, the short lever arm 72 is hinged, extending diagonally downwards into the standpipe 12 and connected via the joint 73 to the tension-compression rod 54, which in this situation is in its uppermost position. This corresponds to the Fig. 1 situation shown on the left, in which the supporting frame 14 is folded in.

[0046] To clamp, the long lever arm 74 is pivoted upwards, which is shown in the three following partial images of the Fig. 5 is shown. Deflected via the horizontal axis of rotation 76, the end of the long lever arm 74 connected to the short lever arm 72 moves downwards and, via the joint 73, takes the pull-push rod 54 downwards, thus pulling the second roller holder 36 of the pulley block 32 downwards and thus clamping the support structure 14. It can also be seen that a comparatively large transmission ratio is achieved via the ratios of the lengths of the sections of the long lever arm 74, relative to the horizontal axis of rotation 76, so that the support structure 14 is clamped with comparatively little expenditure of force.

[0047] The two right-hand images of the Fig. 5 show the situation shortly before and upon reaching the final clamped position. In the second-to-last illustration (second from the right), the long lever arm 74 and the short lever arm 72 form a straight line. In this configuration, the joint 73 is at its lowest point, meaning that the supporting frame 14 is clamped to its maximum.

[0048] When the long lever arm 74 is pivoted further upwards to its end position parallel to the standpipe 12, the short lever arm 72 bends away from the long lever arm 74 again, so that the joint 73 assumes a slightly higher position than at its lowest point. The support frame 14 is thus minimally relaxed, whereby in this position the tension on the support frame 14 is the tension intended for the clamped operation of the support frame 14. This tension is slightly lower than the tension at the lowest point of the joint 73. This means that in order to relax the support frame 14 and to pivot the long lever arm 74 downwards from its upward-pointing end position, a force must be applied which is greater than the force acting on the long lever arm 74 or on the support frame 14 in the end position.In other words, the force ratios are such that the long lever arm 74 is pulled toward the standpipe 12 between the second-to-last position shown and the end position shown on the right. Force must therefore be applied up to the position where the short lever arm 72 and the long lever arm 74 are aligned. Only after the joint 73 has passed its lowest point during guying do the force ratios support the further relaxation of the support structure 14. This can also be supported by manually actuating the long lever arm 74 downwards, since the rigid pull-push rod 54 transmits the upward movement of the joint 73 to the second roller holder 36 of the pulley block 32.

[0049] The stop body 78 may also have a clamping recess for the long lever arm 74 of the hand lever 70, which further assists in locking the long lever arm 74.

[0050] The Figuren 4 und 5 The actuating mechanisms 50 shown are partially arranged close to the ground, which means that a person operating the actuating mechanism 50 does not stand in the way of the opening support structure 14.

[0051] All mentioned features, including those revealed solely in the drawings 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

[0052] 10 Clamping device 12 Standpipe 14 Support frame 16 Support arm 17 Umbrella support 18 Support strut 20 First center bracket 22 Second center bracket 30 Spreading mechanism 32 Pulley block 33 Upper suspension 34 First pulley holder 35 Upper attachment point 36 Second pulley holder 37 Lower attachment point 38 Pulleys 39 Deflection pulley 40 Pulley rope 42 Fast end of the pulley rope 50 Operating mechanism 52 Pulley rope 54 Rigid pull-push rod 60 Lever 62 Hand pulley rope 63 Deflection pulley 64 Hand crank 65 Hook 66 Foot pedal 67 Pivot point 68 Hand lever 70 Hand lever 72 Short lever arm 73 Joint 74 Long lever arm 75 Handle 76 Horizontal axis of rotation 78 Anchor body 80Locking device 90Power assistance device 92Coil spring 93Coil spring stop 94Weight

Claims

1. A spreading mechanism (30) for a clampable device (10) comprising a standpipe (12) and a clampable support frame (14) with a plurality of star-shaped, diverging pairs of support arms (16) and support struts (18) articulated to the support arms (16), wherein the support arms (16) are articulated to a first central support (20) and the support struts (18) are articulated to a second central support (22), and the spreading mechanism (30) is designed to clamp or close the support frame (14) by reducing or increasing the distance between the first central support (20) and the second central support (22), characterized in thatthe spreading mechanism (30) comprises an actuating mechanism (50) and a pulley block (32) with a pulley cable (40), a fixedly attached first roller holder (34) and a movable second roller holder (36) each having one or more rollers (38) over which the pulley cable (40) is guided, wherein the actuating mechanism (50) is connected to the movable second roller holder (36) of the pulley block (32) and a fast end (42) of the pulley cable acts in a displacing manner on the first central holder (20) and / or the second central holder (22) in order to change their distance from one another.

2. Spreading mechanism (30) according to claim 1, wherein the pulley (32) is arranged inside the standpipe (12).

3. Spreading mechanism (30) according to claim 1 or 2, wherein the pulley (32) has a gear ratio between 2:1 and 10:1, in particular between 4:1 and 8:

1.

4. Spreading mechanism (30) according to one of claims 1 to 3, comprising a force assisting device (90) which is designed to permanently exert a force on the movable second roller holder (36) of the pulley block (32) which is directed in the direction of clamping the support frame (14).

5. Spreading mechanism (30) according to claim 4, wherein the force assisting device (90) is designed as a spring device with a spring or a combination of springs, in particular a spiral spring (92), a gas pressure spring and / or a gas tension spring, and / or as a weight (94).

6. Spreading mechanism (30) according to claim 5, wherein the spring device has a linear or degressive or progressive spring characteristic.

7. Spreading mechanism (30) according to one of claims 1 to 6, wherein the actuating mechanism (50) is connected in a tensile-resistant manner to the movable second roller holder (36) of the pulley (32).

8. Spreading mechanism (30) according to claim 7, wherein the actuating mechanism (50) is connected to the movable second roller holder (36) of the pulley (32) via a pull rope (52), a pull chain or via a rigid pull-push rod (54).

9. Spreading mechanism (30) according to one of claims 1 to 8, wherein the actuating mechanism (50) is designed as a lever (60), electric winch, as a hand pull rope (62), as a hand crank (64), foot pedal (66) or hand lever (68) for a pull rope (52), or as a hand lever (70) for a rigid pull-push rod (54).

10. Spreading mechanism (30) according to one of claims 1 to 9, wherein a locking device (80) for the actuating mechanism (50) is included or the actuating mechanism (50) is self-locking.

11. Spreading mechanism (30) according to claim 9 or 10, wherein the hand lever (68, 70) has a short lever arm (72) and a long lever arm (74), wherein the short lever arm (72) is connected at one end to the movable second roller holder (36) of the pulley (32) and is pivotally connected at its other end to the long lever arm (74), wherein the long lever arm (74) is pivotally attached to the standpipe (12) about a horizontal pivot axis (76) at a first distance from the connection to the short lever arm (72), wherein the first distance and a second distance of the horizontal pivot axis (76) from the standpipe (72) are selected such thatthat when the clampable support frame (14) is opened by pivoting the long lever arm (74) from a downward-facing end position to an upward-facing end position, the end of the short lever arm (72) connected to the movable second roller holder (36) of the pulley (32) passes through a low point and, upon reaching the upward-facing end position of the long lever arm (74), assumes an end position above the low point.

12. A clampable device (10) comprising a standpipe (12) and a clampable support frame (12) with a plurality of star-shaped, diverging pairs of support arms (16) and support struts (18) articulated to the support arms (16), wherein the support arms (16) are articulated to a first central support (20) and the support struts (18) are articulated to a second central support (22), as well as a spreading mechanism (30) designed to clamp or close the support frame (14) by reducing or increasing the distance between the first central support (20) and the second central support (22), characterized in that the spreading mechanism (30) is designed according to one of claims 1 to 11.

13. Clampable device (10) according to claim 12, characterized in that it is designed as a standing umbrella, in particular a center mast umbrella or side arm umbrella, as a rotary clothes dryer or as a combination of a rotary clothes dryer and a center mast umbrella.

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