Form-fitting adjustment device for one roller

Description

field of technology

[0001] The invention relates to a positive locking device for a roller, comprising a wheel, a fork and a rotation-locking engagement part, wherein the wheel of the roller can be rotationally locked with respect to a geometric wheel axis via the positive locking device, wherein, furthermore, to displace the rotation-locking engagement part from a starting position to an engagement position, a first spring acts on the rotation-locking engagement part and is held on a pivotable lever part.

[0002] The invention also relates to a positive locking device for a roller, comprising a wheel, a fork, and a rotary locking engagement part, wherein the wheel of the roller can be rotary-locked with respect to a geometric wheel axis via the positive locking device, wherein, furthermore, the rotary locking engagement part can be actuated via a lever part to move the rotary locking engagement part from a starting position to an engagement position and / or from the engagement position to the starting position, wherein, furthermore, the lever part can be actuated by means of a plunger part, and the plunger part is fork-shaped with plunger extensions of different lengths, wherein only one plunger extension is arranged to act on the lever part. State of the art

[0003] Positive locking devices of the type in question are known, particularly for rollers, comprising a wheel and a fork, and optionally a mounting pin. The positive locking device allows the wheel of the roller to be locked in rotation with respect to its geometric axis. For this purpose, the rotation-locking engagement element, which in known solutions is, for example, arranged on the fork or mounting pin side, is engaged with at least one opposing engagement element on the wheel side in a positive locking position. In this context, it is also known to provide a toothed section on the wheel side, circumferential with respect to the wheel axis, to form the opposing engagement element, into which the rotation-locking engagement element can engage to activate the positive locking device.It is also known in this context to preload such a rotation-locking engagement part in the engagement position, as well as possibly in the non-engagement position, with a spring.

[0004] For example, reference is made in this context to WO 2019 / 053 004 A1 (US 11 065 913 B2), from which a roller, here a swivel roller, is known that, in addition to the rotational mobility of the wheel, also has pivot mobility of the roller fork pivot axis. In this roller, the rotation-locking engagement element, for interaction with a toothed rim of the wheel, can be displaced essentially transversely to a mounting pin axis of the roller, and, accordingly, during normal use, essentially oriented along a horizontally aligned line. The spring acting on the engagement element acts on the rotation-locking engagement element at least in the engaged position or a prepared engaged position.

[0005] Furthermore, it is also known, for example from the aforementioned WO 2019 / 053 004 A1, to act on the lever part of the positive locking device via a plunger part, which is guided, for example, in the area of ​​the mounting pin of the roller and can be displaced along a mounting pin axis, in order to displace the rotary locking engagement part from the starting position to the engagement position and / or vice versa.

[0006] From WO 2012 / 171 816 A1 (US 2014 / 0 109 342 A1) a positive locking device for a roller is known, in which a first spring acts on a linearly movable plunger part and the plunger part acts on a lever part which, against the action of a second return spring, displaces a rotary locking engagement part into an engagement point.

[0007] In a positive locking device known from DE 10 2014 113 460 A1, a first spring acts against a lever part to linearly displace the lever part. A second spring, which is also arranged to act on the lever part, moves linearly in accordance with the lever part as a result of tension or relaxation of this spring.

[0008] For further information on the prior art, reference should be made to DE 89 15 173 U1 (US 5 133 106 A). The positive locking device known from this patent provides a linearly movable engagement element that can be moved into the engagement position by means of a wedge gear. WO 2008 / 148169 A1 discloses that a spring acts on a lever element forming a load and force arm. DE 20 2017 100 939 U1 discloses that a lever element acts on a plunger element. Summary of the invention

[0009] With regard to the aforementioned prior art, the invention addresses the problem of advantageously designing a positive locking device of the type in question.

[0010] This problem is initially solved in the subject matter of claim 1, wherein the first spring forms a lever arm, a second spring held on the lever part can be tensioned for return movement to the starting position when the rotary locking engagement part is moved into the engagement position, and the first spring is stronger than the second spring.

[0011] The rotating locking element is acted upon by a lever arm, which is part of the first spring and is itself spring-loaded, to move it from its initial position towards the engagement position. The spring force of the first spring forming this lever arm is selected to be large enough that the second spring is tensioned when the rotating locking element is moved towards the engagement position. When the load acting on the lever element is removed, the tensioned second spring allows the lever element, and preferably also the rotating locking element, to return to its initial position.

[0012] In a typical operation of the positive-locking device, where the rotating locking element can engage the counter-engagement element on the wheel side without resistance, the lever arm of the lever element, formed by the first spring, acts essentially rigidly on the rotating locking element to displace it. Accordingly, in such a typical operation, the only effect (initially) is to overcome the spring force of the second, weaker spring, which builds up a preload during this displacement to return the lever element to its original position. This results in advantageously reduced switching forces compared to the prior art.

[0013] Preferably only in a situation where the rotating locking element cannot immediately engage with the corresponding mating element of the impeller, for example, in a situation where the engagement teeth of the rotating locking element encounter the engagement teeth of the mating element, the first spring, forming the lever arm, comes into effect in addition to the second spring. The resulting spring force of the first spring causes the rotating locking element to automatically move into the locking engagement position as soon as the impeller, and thus the mating element, has rotated a few degrees further, allowing the engagement teeth of the rotating locking element to engage in the troughs between the engagement teeth of the mating element.

[0014] The aforementioned problem is also solved in the subject matter of claim 10, wherein the focus is on the fact that the plunger extensions extend substantially in a vertical direction in a conventional orientation of the roller and that the plunger extensions extend on both sides and along a mounting pin axis of a mounting pin which surrounds a geometric pivot axis.

[0015] In the case of an overall design of the tappet section that is essentially U-shaped, the tappet extensions form U-shaped legs that are essentially parallel to each other and are further connected by a U-shaped bridge. A section of the impeller can extend between the U-shaped legs.

[0016] Typically, and preferably, the rotary locking engagement part can be linearly displaced from the initial position to the engagement position and back, more preferably essentially starting from the geometric impeller axis along a horizontal line with reference to the usual operating position of the roller.

[0017] The U-shaped legs of the plunger section, forming the plunger extensions, are of different lengths in their essentially vertical extension in their usual operating position, extending from the connecting U-shaped web. In the operational configuration, only one of the two plunger extensions is suitable for acting on the lever part of the positive locking device. This advantageously allows the plunger section to be arranged in rollers with different impeller diameters. With a smaller impeller diameter, the plunger section is preferably arranged so that the shorter plunger extension is oriented to act on the lever part of the positive locking device, while with a larger impeller diameter, the longer plunger extension is arranged accordingly within the roller.

[0018] In a typical orientation of the roller, the plunger extensions extend essentially vertically on both sides and along a mounting pin axis, which mounting pin axis preferably passes through the aforementioned U-shaped web of the plunger part essentially in its center. By rotating the plunger part by 180 degrees relative to the mounting pin axis, only the shorter or only the longer plunger extension is arranged to act on the lever part of the positive locking device.

[0019] In particular, this makes it advantageous from a manufacturing perspective to produce rollers with different wheel diameters, essentially with the exception of the fork and the wheel, using the same components, especially with regard to the elements for forming the mounting pin and the elements for forming the positive locking device and with regard to the plunger part.

[0020] It is conceivable that the first spring is formed by a lever arm of the lever part, that with the displacement of the rotary locking engagement part into the engagement position a second spring can be tensioned for the return movement to the starting position, and that the first spring is stronger than the second spring, with the plunger part further being fork-shaped, with plunger extensions of different lengths, whereby only one plunger extension is arranged to act on the lever part.

[0021] It is also conceivable that the lever arm is designed as a spring arm, particularly with regard to initially hindering the engagement of the teeth into the tooth valleys. Preferably, it may be provided that, upon displacement of the rotation-locking engagement part into the engagement position, a second spring can be tensioned to return it to its initial position, and / or that the first spring is stronger than the second spring. Furthermore, the features described below regarding the first described solution can also be implemented individually or in combination.

[0022] Features of the invention are explained below, also in the description of the figures, often in their preferred relation to the subject matter of claim 1 and / or the further independent claim or to features of further claims. However, they may also be relevant in relation to only individual features of claim 1 and / or the further independent claim or the respective further claim, or independently of each other.

[0023] Advantageously, in the initial position of the positive locking device, i.e., in the non-engaged position of the rotating locking element, both the first and second springs can be essentially relaxed. According to this preferred design, at least one of the two springs, particularly the second spring, is only subjected to stress during the process of reaching and maintaining the engaged position. Furthermore, the first spring can even be essentially relaxed in the engaged position.

[0024] The first spring can be designed as a torsion spring. In a further embodiment, the second spring can also be designed as a torsion spring. Such a torsion spring typically has two legs, one of which acts on the object to be cushioned, the rotating locking engagement part or lever part, and the other of which rests against a support section that is essentially stationary.

[0025] In a preferred embodiment, the second spring can act between the lever part and a fork-mounted retaining part. The retaining part can be a separate component from the fork, which can be fixed to the fork. Furthermore, the retaining part can be designed to accommodate both a fork for a wheel with a larger diameter and a fork for a wheel with a smaller diameter. The retaining part can thus be part of the overall positive locking device, which, as described above, is designed to be suitable for both wheel diameters.

[0026] Preferably, both springs, i.e., both the first spring and the second spring, act on the lever part at one end, particularly via a spring leg. With respect to a geometric axis of rotation of the lever part, the spring legs of the two springs can optionally, and preferably, act on the lever part in opposite directions.

[0027] The first, stronger spring can, preferably, act alone between the lever part and the rotation-locking engagement part. Preferably, this first spring also rotates together with the lever part when the lever part is rotated or pivoted accordingly. Furthermore, the spring-loaded lever arm of this first spring, acting on the rotation-locking engagement part, can be subjected to a corresponding counter-load, for example, in the case of misalignment of the teeth ("tooth-on-tooth position"), thereby building up a restoring spring force via the rotation-locking engagement part.

[0028] In a further embodiment, the second spring can, particularly in a region between its spring legs, for example with a helical section, include a mounting pin of the mounting part. Preferably, this mounting pin centrally accommodates the geometric pivot axis of the mounting part.

[0029] According to a possible further development, the first spring, in particular with a spring leg associated with the lever part, can be guided in a groove of the lever part. The groove can be designed with a dimension transverse to the longitudinal dimension of the spring leg adapted to the diameter of the spring leg. The spring leg can essentially rest loosely in this groove, but can also be clamped in it.

[0030] The lever part can also have two actuation ends. One actuation end can, preferably, be formed by a rigid stop element to act on the rotation-locking engagement element in the direction of the initial position. Furthermore, a drive section of the rotation-locking engagement element can be positioned substantially between this actuation end of the lever part and the spring-loaded lever arm acting in the direction of the engagement position.

[0031] In a preferred embodiment, a further actuation end of the lever part, which can be designed essentially opposite the first actuation end described above with respect to the geometric axis of rotation of the lever part, interacts directly with the plunger part, via which plunger part the positive locking device can be actuated.

[0032] The plunger section, which is guided on the mounting pin and / or the fork, is preferably actuated by a switching plunger on the mounting pin side. This switching plunger preferably extends along a pin axis that runs essentially vertically during normal operation of the roller and is further preferably linearly displaceable along this pin axis. In the usual manner, the switching plunger can be actuated via a switching cam received in the mounting pin to switch at least between the initial position and the engagement position of the rotary locking element, but also, and preferably, optionally to actuate a pivoting locking device of the fork.

[0033] The plunger can interact with a second return spring. This second return spring biases the plunger towards a home position in which the positive locking device, in particular the rotary locking engagement part, rests in its initial position. The biasing of the plunger to engage and displace the rotary locking engagement part into the engagement position occurs against the return force of the second return spring. Furthermore, the second return spring can be supported by a fork-mounted support, optionally in the area of ​​the fork-mounted support part. This second return spring can, preferably, be designed in the form of a hairpin spring.

[0034] The switching plunger on the mounting pin side has a separate first return spring, independent of the plunger part, which is preferably arranged in the area of ​​the mounting pin. This can be a conventional cylindrical compression spring, which can further be arranged, for example, concentrically to the geometric axis of the mounting pin.

[0035] It is also possible to design the roller with only one return spring. In this way, the (second) return spring, which preferably acts directly on the plunger part, can, with appropriate adjustment of the spring force, also be used to return the shift plunger, which is then pulled along by the plunger part. Alternatively, if the shift plunger and plunger part are connected, only the (first) return spring associated with the shift plunger can be provided.

[0036] Furthermore, to reduce the overall switching forces, a second return spring is preferably provided only in the area of ​​one fork leg or in the area of ​​one plunger extension of the plunger part. In this way, the second return spring can interact directly with only one of the plunger extensions, while the other plunger extension is not directly acted upon by a return spring.

[0037] The second return spring can act on the underside of the shorter plunger extension, facing the plunger part towards its home position. The longer plunger extension can have a through-hole for the second return spring, whereby, with appropriate alignment of the plunger part, the return spring acts against an upper edge of the opening that corresponds to the roller's normal operating position.

[0038] It is further preferred that only one of the plunger extensions of the plunger part is acted upon by the second return spring, while the other plunger extension is aligned to potentially act on the lever part of the positive locking device. Brief description of the drawings

[0039] The invention is explained below with reference to the accompanying drawing, which, however, only depicts exemplary embodiments. A part that is explained only in relation to one of the exemplary embodiments and is not replaced by another part in a further exemplary embodiment due to the special feature highlighted therein, is thus also described for this further exemplary embodiment as a possible existing part. The drawing shows: Fig. 1 a roller with a positive locking device in a perspective exploded view; Fig. 2 the roller in a further perspective exploded view; Fig. 3 area III in Figure 2in a further perspective exploded view; Fig. 4 a rotary locking engagement part of the positive locking device in a perspective detail view; Fig. 5 the view against the rotary locking engagement part according to arrow V in Figure 4 ; Fig. 6 the view against the rotation-locking engagement part according to arrow VI in Figure 4 ; Fig. 7 the view against the rotation-locking engagement part according to arrow VII in Figure 6 ; Fig. 8 a lever part of the positive locking device in a perspective view; Fig. 9 the view towards the lever part according to arrow IX in Figure 8 ; Fig. 10 the view against the lever part according to arrow X in Figure 9Fig. 11: Another view opposite the lever part according to arrow XI in Figure 10; Fig. 12: The lever part in another perspective view; Fig. 13: A mounting part of the positive locking device in a perspective detail view; Fig. 14: The view opposite the mounting part according to arrow XIV in Figure 13; Fig. 15: The view opposite the mounting part according to arrow XV in Figure 13; Fig. 16: The positive locking device in perspective view; Fig. 17: The positive locking device in view according to arrow XVII in Figure 16 ; Fig. 18 the positive locking device in a further perspective view; Fig. 19 the section along line XIX-XIX in Figure 17 ; Fig. 20 the section according to line XX-XX in Figure 17 ; Fig. 21 a plunger part of the positive locking device in a perspective view; Fig. 22 the section according to section plane XXII in Figure 21; Fig. 23 the section through the roller according to section plane XXIII in Figure 1, relating to an initial position of the positive locking device; Fig. 24 the section through the roller according to line XXIV-XXIV in Figure 23; Fig. 25 an enlarged, plane-offset view of area XXV along a rotation axis of a wheel of the roller in Figure 23 ; Fig. 26 a sectional view according to Figure 23 , concerning an engagement position of the positive locking device; Fig. 27 the enlarged area XXVII in Figure 26 in a representation offset in plane along the axis of rotation; Fig. 28 one of the Figure 25 corresponding representation, however, regarding the intervention position according to Figure 26 ; Fig. 29 one of the Figure 28 corresponding illustration, but concerning a prepared intervention position; Fig. 30 a detailed enlargement according to Figure 27 , however, regarding the prepared intervention position according to Figure 29; Fig. 31 a sectional view through the roller according to Figure 24 , however, concerning a second embodiment of a plunger part of the positive locking device; Fig. 32 the plunger part of the embodiment according to Figure 31 in perspective single view; Fig. 33 the section according to the section plane XXXIII in Figure 32 ; Fig. 34 a sectional view according to Figure 31 , however, concerning a modified arrangement of the plunger part of the second embodiment. Description of the embodiments

[0040] The presentation and description, initially with reference to the Figure 1 and 2 , a roller 1, which in the illustrated embodiments is designed in the manner of a steering roller.

[0041] The roller 1 essentially comprises a wheel 2 and a fork 3, from which a cylindrically shaped mounting pin 4 extends. The mounting pin 4 surrounds a geometric pivot axis x, which, in the normal operating state of the roller 1, projects vertically upwards with respect to the wheel 2.

[0042] The fork 3 can, as also shown, essentially be formed from two fork shell parts 5, 6, each fork shell part 5, 6 carrying a fork leg 7.

[0043] The fork-shaped shell parts 5, 6 of the fork 3, with their fork legs 7, which preferably are substantially congruent in the direction of a rotation axis y, grasp the impeller 2, which is mounted in the preferably provided fork cavity 8. According to the illustrated embodiment, a hollow axle 9 can serve to support the impeller 2. This axle passes centrally through the impeller 2 and is preferably held at each end by the fork legs 7. The resulting geometric rotation axis y of the impeller 2 preferably and substantially extends transversely to the pivot axis x and thus, in the normal operating condition of the roller 1, substantially in a horizontal plane.

[0044] The caster 1 shown can, for example, be positioned on a hospital bed or similar. It can be secured in the usual way using the mounting pin 4.

[0045] In the mounting pin 4, a switching cam 10, pivotably arranged about an actuating axis a, can be provided in the region of an upwardly pointing free end. The actuating axis a can extend substantially perpendicular to the pivot axis x of the roller 1. For rotational engagement of the switching cam 10, the switching cam 10 can have a centrally arranged non-circular, optionally hexagonal coupling opening 11, which, according to the illustrated embodiment, can be penetrated by a shift lever shaft (not shown) for actuation.

[0046] For example, regarding the presentation in Figure 23 A switching plunger 12 is provided below the switching cam 10, by means of which either a swivel locking device 13 and / or a positive locking device 14 can be actuated or released.

[0047] In particular, the adjustment of the swivel locking device 13 and the positive locking device 14, but also the fork shell parts 5 and 6, can be carried out according to the illustration in Figure 1 Furthermore, the hub area of ​​the wheel is also covered by housing shells 15 that overlap.

[0048] The switching plunger 12 is preferably aligned about the pivot axis x in the mounting pin 4 and is preferably rotatably displaceable vertically. For this purpose, the mounting pin 4 can have a diameter-reduced groove 16, also preferably aligned about the pivot axis x, which may optionally be adapted in cross-section to guide the switching plunger 12.

[0049] For example Figure 23As shown, the free end of the shift plunger 12, formed between the opening of the gear 16 and the shift cam 10, can be screwed to a cam section 17, for example. The cam section 17 can preferably have a cup-like shape with a preferably circular cross-section, wherein a diameter-enlarged area can be formed as an annular collar 18 at the end facing away from the shift plunger 12. Furthermore, the cam section 17 of the shift plunger 12 is preferably guided vertically along the pivot axis x within the mounting pin 4, as shown in the illustrations.

[0050] Furthermore, the section of the cam part 17 with a reduced diameter compared to the annular collar 18 can be surrounded by a first return spring 19, with one end of the first return spring 19 bearing against the underside of the annular collar 18. The other, opposite end of the spring can bear against an edge of the channel 16. Thus, the shift plunger 12 can be spring-loaded towards the shift cam 10 by means of the first return spring 19. In addition, and preferably, the end face of the optionally provided annular collar 18 facing the shift cam 10 can have a central projection in the form of a counter-cam 20.

[0051] The switching plunger 12 interacts with the preferably provided counter cam 20 with the facing control surface 21 of the switching cam 10, which control surface 21 may further have two control recesses 22 and 23 arranged one behind the other in the circumferential direction of the switching cam 10, which have different depths with respect to the radial distance to the actuating axis a.

[0052] The switching cam 10 is limited in its pivoting movement in the circumferential direction of the control surface 21. For this purpose, as shown, a stop projection 24 on the mounting pin side can engage in a corresponding circumferential groove 25 of the switching cam 10. As can be seen, for example, in the illustration in Figure 23 The circumferential groove 25 is essentially located opposite the control recesses 22 and 23 with reference to the actuating axis a, and the circumferential groove 25 extends over an angle of approximately 90 degrees.

[0053] The shift plunger 12 extends, preferably towards the wheel 2, in the direction of the fork cavity 8 or into it. The fork cavity 8 preferably surrounds a circular cross-sectional projection of the shift plunger 12, which projection may have a larger diameter than an upper region of the shift plunger 12. The projection can function as a detent plate 26, which may be formed on the shift plunger 12 transversely to the pivot axis x.

[0054] The detent plate 26 can have detent features 27 on its surface facing the switching cam 10. In a so-called fixed roller position, in which the fork 3 with the wheel 2 preferably assumes only two positions offset by 180 degrees relative to the mounting pin 4, these detent features 27 can be pressed flat against the underside of a directional locking element 28 by the spring force of the first return spring 19. The directional locking element 28 can be fixed to the fork 3, for example, in a region where the fork 3 as a whole is pivotably mounted on the mounting pin 4 via a bearing 29 about the pivot axis x relative to it.

[0055] The detent plate 26 with its detent features 27, the direction locking element 28 and a rotary locking element 30 which is described in more detail below are essentially part of the swivel locking device 13.

[0056] The fixed roller position can be achieved by rotating the switching cam 10 into a co-engagement position of the counter cam 20 with the control recess 23, or any other equivalent configuration. The fixed roller position can be adjusted relative to the position shown in Figure 23 In the neutral position shown, in which the counter cam 20 engages in the further control recess 22, the given spring force applied via the first return spring 19, with reference to the figures, causes the cam part 17 and the switching plunger 12, and thus also the detent plate 26, to be raised into the collaborating position with the direction locking part 28.

[0057] On the underside of the detent plate 26, facing away from the detent features 27, the switching plunger 12 may have further rotation-locking projections 31. These may, for example, run coaxially to the pivot axis x in the circumferential direction of the detent plate 26.

[0058] From the detent plate 26, a cylindrical extension 32, preferably circular and with a reduced diameter compared to the detent plate 26, can extend from the shift plunger 12 in the direction of the impeller 2. This extension can, in turn, be guided in a centrally arranged through-opening of the rotary locking element 30, which is arranged around the pivot axis x. The rotary locking element 30, located between the impeller 2 and the detent plate 26 in the fork recess 8, can also be fixed to the fork 3 in a rotationally fixed manner, just like the directional locking element 28, and can, for example, be designed as a stamped and bent part.

[0059] The rotation-locking element 30 can have locking receptacles adapted to the geometry of the rotation-locking projections 31. Preferably, the rotation-locking element 30 is supported on the fork side by spring elements 70 acting essentially in the direction of the pivot axis x.

[0060] Due to the interaction of the rotary locking projections 31 of the detent plate 26 and the locking receptacles in the rotary locking part 30, the roller 1 can be fixed in different pivot positions about the pivot axis x. For this purpose, the switching cam 10 can be pivoted into a position about its actuating axis a, in which the counter cam 20 is positioned as shown in the illustration. Figure 26 The counter-cam 20, together with the shift plunger 12, can be moved downwards against the force of the first return spring 19, as shown in the illustrations. The rotation-locking projections 31 can engage in the associated locking receptacles to prevent pivoting.

[0061] At the same time, and preferably, a rotational locking of the impeller 2 can also be achieved in this position. The positive locking device 14 serves this purpose.

[0062] Part of the positive locking device 14 is a fork-shaped plunger part 33, which in a first embodiment is located in the Figures 21 and 22 shown in individual illustrations and in a role 1 according to the illustrations in the Figures 1 to 30 is used.

[0063] The plunger section 33 has a U-shaped bridge section 34, which, in the usual arrangement, extends in a direction transverse to the pivot axis x in the area of ​​the forked cavity 8 on the underside of the extension 32 of the switching plunger 12. This bridge section 34 is essentially centrally penetrated by the pivot axis x and has plunger extensions 35 and 36 at each end, extending downwards and away from the switching plunger 12, essentially in alignment with the pivot axis x. Together with the plunger extensions 35 and 36 and the bridge section 34, this results in an overall essentially U-shaped configuration of the plunger section 33, with the opening of the U being penetrated by the running surface of the impeller 2, so that the plunger extensions 35 and 36 extend on both sides of the impeller 2.

[0064] In a further embodiment, the plunger part 33 is guided linearly in the orientation of the pivot axis x via the plunger extensions 35 and 36. For this purpose, the plunger extensions 35 and 36 have outwardly directed guide projections 37 that engage in correspondingly positioned guide openings 38 in the area of ​​the fork-shaped shell parts 5, 6. The guide openings 38 are further designed such that, when the guide projections 37 engage, they allow a limited displacement of the plunger part 33 as a whole along the pivot axis x.

[0065] On the upper side of the bridge section 34, the plunger part 33 can carry pins 39 which can engage in appropriately positioned and adapted openings of the rotary locking part 30, whereby the rotary locking part 30 is connected to the fork 3 via the plunger part 33 in a rotationally fixed manner.

[0066] With reference to a side view of the plunger part 33, in particular to a plunger extension 35, 36, in which the axis of rotation y of the impeller 2 is represented as a point and the pivot axis x as a line, control surfaces 40 extending obliquely are formed on the underside of the respective free end of a plunger extension 35, 36, for acting on a lever part 41 of the positive locking device 14.

[0067] In a preferred embodiment, this is done with reference to the representations, for example in Figure 23 , downward movement of the plunger part 33 by being actuated via the shift plunger 12. However, preferably no positive locking occurs that would allow the plunger part 33 to be returned to the neutral position together with the shift plunger 12 due to the spring action via the first return spring 19, correspondingly with reference to the Figure 23upwards, to be dragged along. Rather, a separate second return spring 42, for example in the form of a hairpin spring, is provided for this purpose, which is held in a fork-shaped shell part 5, 6 and whose spring arm acts against one of the plunger extensions 35, 36. Preferably, the second return spring 42 acts in conjunction with the plunger extension which, due to the arrangement of the plunger part 33, is not designed for direct interaction with the lever part 41.

[0068] During the Figures 1 to 30 In the first embodiment shown, the second return spring 42 acts on the underside against the plunger extension 36, which is not positioned to act on the lever part 41 of the positive locking device 14, when the plunger extensions 35 and 36 are of equal length.

[0069] Both return springs 19 and 42 essentially act in the same direction, namely with reference to the illustrations, for example Figure 23, in alignment of the pivot axis x upwards in the direction towards the switching cam 10. Preferably, this results in an independent spring action of switching plunger 12 and plunger part 33.

[0070] In addition to the lever part 41, another essential component of the positive locking device 14 is a rotary locking engagement part 43, which is preferably designed to interact with a circumferential toothing 44 provided on the inside of the wheel.

[0071] The rotation-locking engagement part 43 can be movably mounted on a mounting part 45 fixed to the fork leg. The slidability is provided in particular by a sliding projection 46, which has a T-shaped cross-section transverse to a displacement direction r of the rotation-locking engagement part 43 and is guided in a cross-section-adapted sliding receptacle 47 of the mounting part 45 (compare, for example, Figures 4 , 13 and 16 ).

[0072] The arrangement and orientation of the rotation-locking engagement part 43 can be further selected such that the rotation-locking engagement part 43 extends along a side view, for example, according to Figure 25 The line b can be moved perpendicular to the pivot axis x. This is preferably a substantially horizontal line b in the usual orientation of the roller 1, such that, with reference to a projection into a plane in which the axis of rotation y is represented as a point, for example according to... Figure 25 , the displacement direction r of the rotary locking engagement part 43 essentially includes a right angle α to the direction of movement c of the switching plunger 12 and the plunger part 33.

[0073] Facing the toothing 44 of the impeller 2, the rotation-locking engagement part 43 has two or more, in the illustrated embodiment four, locking teeth 48 spaced apart from each other in the circumferential direction of the impeller 2, their spacing and design adapted to the toothing 44, in the orientation of the axis of rotation y and offset in plane from the sliding process 46.

[0074] In its installed and operational state, the rotation-locking engagement part 43, positioned above and at a vertical distance from the sliding projection 46, further carries a plate-like support section 49. This support section 49 may rest on and slide over the sliding receptacle 47 of the mounting part 45, and a cam-like engagement projection 50 is formed on this support section 49. The engagement projection 50 serves to interact with the lever part 41.

[0075] The retaining part 45 is arranged and held inside one of the fork shell parts 5, 6, for which purpose the retaining part 45 may have outwardly pointing fastening pins 51 which engage in correspondingly positioned receiving openings 52 of the fork shell part 5.

[0076] Opposite the fastening pins 51, the mounting part 45 carries a mounting pin 53 pointing inwards. On this, the lever part 41 is pivotally mounted about a pivot axis z, which is aligned parallel to the axis of rotation y and perpendicular to the displacement direction r of the rotation-locking engagement part 43, by means of a correspondingly positioned pin receptacle 54.

[0077] The lever part 41 has a first actuating end 55 for interaction with the drive projection 50 of the rotary locking engagement part 43. Furthermore, extending from this first actuating end 55 beyond the pin receptacle 54, a second actuating end 56 is formed in the form of a shoulder extending approximately in the direction of the pivot axis z. This second actuating end 56 serves for interaction with the plunger part 33, in particular with the control surface 40 of the associated plunger extension.

[0078] Lever part 41 and rotary locking engagement part 43 are preferably, as also shown and described, slidably and rotatably mounted together on the mounting part 45. It is further preferably provided that the positive locking device 14 thus designed is only provided on one side, assigned only to one fork leg 7, and in particular only to one fork shell part 5.

[0079] In the form of a thickening of the lever part 41 extending in the direction of the pivot axis z to the area having the actuation ends 55 and 56, a contact block 57 is further integrally formed with the actuation ends 55 and 56 and preferably of the same material.

[0080] Furthermore, the positive locking device 14 preferably includes two springs, both of which are preferably designed as torsion springs. A first spring 58 is provided, which acts between the lever part 41 and the rotation-locking engagement part 43, and a second spring 59, which acts between the lever part 41 and the fork-mounted retaining part 45.

[0081] Starting from a central coil section 60 received by the mounting pin 53, a spring leg 61 extends with respect to the second spring 59, resting against a support block 62 of the fork-mounted mounting part 45, while the other spring leg 63 is supported in the area of ​​the first bearing end 55 of the lever part 41, so that this results in a corresponding spring load on the lever part 41 in the direction of an initial position or basic position that allows the free movement of the wheel 2.

[0082] A spring leg 64 of the first spring 58 is guided in a groove 65 in the area of ​​the contact block 57 of the lever part 41, and may also be clamped. This spring leg 64 acts on an area of ​​the contact block 57 facing away from the second actuation end 55 of the lever part 41, whereas the corresponding coiled section 66 is located essentially adjacent to the second actuation end 56, from which the further spring leg 67 extends, forming a lever arm 68 of the lever part 41 and designed to act on the engagement projection 50 of the rotation-locking engagement part 43. The spring-loaded lever arm 68 thus configured acts on the side of the engagement projection 50 facing away from the first actuation end 55 of the lever part 41.

[0083] The two springs 58 and 59 each act on the lever part 41 via a spring leg 63, 64, with both springs 58 and 59 further acting in the, in particular in the Figures 23 to 25The neutral or starting position shown is preferred and essentially relaxed, and accordingly does not or does not significantly exert a spring force on the lever part 41 and / or the rotation-locking engagement part 43.

[0084] Under, possibly stop-limited, rotational displacement of the switching cam 10 in direction d (compare Figure 26 A switching position is reached in which, due to the lowering of the switching plunger 12 in the direction of movement c, the counter cam 20 comes into contact with the control surface 21. In addition to the previously described possible pivot locking of the fork 3 relative to the mounting pin 4 due to the positive engagement between the rotary locking part 30 and the rotary locking projections 31 of the detent plate 26, the second actuation end 56 of the lever part 41 is further actuated via the dragged plunger part 33 and the plunger extension 35 as well as via its control surface 40.

[0085] During this lowering movement, the lever part 41 is rotated about its pivot axis z in the direction of arrow e (compare Figure 28 The first spring 58 pivots, and the first spring 58, via the lever arm 68 formed by the spring leg 67, moves the rotation-locking engagement element 43 linearly in the displacement direction r, bearing against the drive projection 50. Preferably, no or no significant change in angle occurs between the spring legs 67 and 64 of the first spring 58 during the movement of the rotation-locking engagement element 43 – at least up to a possible locking position of the rotation-locking engagement element 43. Rather, the first spring 58 preferably remains essentially relaxed up to a locking position.

[0086] The rotation-locking engagement element 43 is moved by the first spring 58, in particular by the resilient lever arm 68, towards a positive-locking position with the teeth 44 of the impeller 2. In such a positive-locking position, the locking teeth 48 of the rotation-locking engagement element 43 engage with the teeth 44 of the impeller 2, so that the latter is rotationally locked (see also Figure 27 ).

[0087] As the lever part 41 pivots towards the locking position, the second spring 59 is tensioned, acting as a return spring for the lever part 41. When the positive locking position is assumed virtually without resistance, as described above, only the force of the second spring 59 needs to be overcome with respect to the positive locking locking device 14.

[0088] During normal use of roller 1, however, the situation repeatedly arises that, when attempting to engage the locking position, the locking teeth 48 of the rotary locking engagement part 43 engage the teeth of the gear 44 on the wheel 2 in a blocking manner (compare the illustration in Figures 29 and 30). The proposed solution, however, allows for complete displacement of the shift plunger 12 and plunger part 13, as well as complete rotation of the lever part 41, even in this situation, despite the complete obstruction of the rotary locking engagement part 43. Only the spring leg 67, which acts on the engagement projection 50 of the rotary locking engagement part 43 and forms the lever arm 68, yields due to the blockage, thereby generating a spring force in the first spring 58, which is inherently stronger than the second spring 59.Preferably, this spring force, which forms a force reserve, is generated solely in such a locking position ("tooth-on-tooth"). A subsequent rotational displacement of the impeller 2 by one or two degrees ensures that the locking position is automatically engaged while the spring tension of the first spring 58 is reduced.

[0089] To release this locking position (and, if applicable, the pivot locking position), the switching cam 10 is moved back against the direction of rotation d, with the counter cam 20 engaging in one of the control recesses 22 or 23. Consequently, the switching plunger 12 is moved back upwards by the action of the first return spring 19, and the plunger part 33 is moved back upwards by the action of the second return spring 42, as shown in the illustrations. Due to the lack of support for the second actuating end 56 on the associated plunger extension 35, the lever part 41 can pivot back against the direction of rotation e by releasing the spring force of the second spring 59. The first actuating end 55, which is supported on the drive projection 50, then pushes the rotation-locking engagement part 43 back linearly in the direction of displacement r. The locking teeth 48 leave the area of ​​the toothing 44, after which the wheel 2 can again rotate freely about its axis of rotation y.Due to the preferably stress-free arrangement of the first spring 58, in the course of this controlled retraction of the rotation-locking engagement part 43 via the lever part 41, there is no or no significant overcoming of a force arising in the first spring 58 and opposing the retraction.

[0090] Preferably, the starting position of the rotary locking engagement part in particular is limited by a stop.

[0091] As can be seen from the sectional view in Figure 24 As can be seen, the second return spring 42 is arranged opposite the positive locking device 14 with reference to a wheel center plane considered perpendicular to the axis of rotation y, so that this second return spring 42 acts with a spring leg of the preferably designed hairpin spring against the exposed plunger extension 36 on the underside.

[0092] Furthermore, the pesty processes 35 and 36 are located in the Figures 1 to 30The first embodiment shown, starting from bridge section 34, is essentially designed with the same length l (compare Figure 22 ).

[0093] The Figures 31 to 34 Figure 1 shows a further embodiment of the plunger part 43, in which a plunger extension 36 is provided with a length l' that is chosen to be greater than the length l of the further plunger extension 35. For example, the plunger extension 36 can have a length l' that is approximately 1.2 to approximately 1.6 times, or in a further example approximately 1.4 times, the length l of the shorter plunger extension 35.

[0094] Both tappet extensions 35 and 36 are preferably formed on their underside with the control surfaces 40 described above.

[0095] Figure 31Figure 1 shows an arrangement of a plunger part 33 designed in such a way that the plunger part 33 is oriented such that – according to the first embodiment described above – the shorter plunger extension 35, having length l, is arranged to act on the lever part 41, while the longer plunger extension 36, with length l', is arranged to be associated with the second return spring 42. With the second return spring 42 positioned in the same way within the associated fork-shaped shell part 6, a through-opening 69 is provided in the longer plunger extension 36 for interaction with the second return spring 42.

[0096] This arrangement described above is chosen for a roller 1 with a wheel 2 having a diameter dimension D.

[0097] By rotating the plunger part 33 by 180 degrees relative to the other components of the positive locking device 14, a roller 1 can also be fitted with a wheel 2 using essentially the same components (with the exception, in particular, of the fork 3 and the wheel 2), which wheel 2 has a different design compared to the embodiment according to Figure 31 enlarged diameter D' is provided (compare Figure 34 ). Thus, for a larger diameter impeller 2, the following results according to Figure 34 an arrangement in which the longer plunger extension 36 is arranged to act on the lever part 41 and the second return spring 42 rests on the underside of the shorter plunger extension 35.

[0098] In particular, the lever part 41, the rotation-locking engagement part 43, the mounting part 45, the second return spring 42, as well as the springs 58 and 59, and furthermore the asymmetrically designed plunger part 33, can advantageously be used, as can, more preferably, the essential parts for forming the mounting pin 4 and the components for rotation locking for both impeller diameters D and D'. List of reference symbols

[0099] 1 role 28 Directional detection part 2 balance bike 29 Storage 3 Fork 30 Rotary locking part 4 Mounting pin 31 Rotational blocking advantage 5 Fork shell part 32 extension 6 Fork shell part 33 plunger part 7 fork leg 34 Bridge section 8 fork cavity 35 Pestle process 9 Hollow axle 36 Pestle process 10 Shift cam 37 Leading position 11 Coupling opening 38 Opening of the tour 12 shift plunger 39 Cones 13 Swivel locking device 40 Control surface 14 Positive locking device 41 Lever part 42 second return spring 15 housing shell 43 Rotation locking engagement part 16 aisle 44 Interlocking 17 camshaft 45 Mounting part 18 Ring collar 46 gliding process 19 first return spring 47 Sliding mount 20 Counter cam 48 Locking tooth 21 Control surface 49 Support section 22 Tax trough 50 Taking advantage 23 Tax trough 51 Mounting pin 24 Stop projection 52 opening 25 circumferential groove 53 Mounting pin 26 Rest plate 54 pin socket 27 Raster shape 55 first end of exposure 56 second end of operation y axis of rotation 57 Investment block z Swivel axis 58 first spring 59 second spring 60 winding section D diameter 61 Spring leg D' diameter 62 support bracket 63 Spring leg 64 Spring leg α angle 65 Nut 66 winding section 67 Spring leg 68 Lever arm 69 Access opening 70 spring element a Actuating axis b line c Direction of movement d Direction of rotation e Direction of rotation l length l' length r Direction of displacement x Swivel axis

Claims

1. Positive locking brake device (14) for a caster (1), comprising a wheel (2), a fork (3), and a rotational-locking engagement member (43), wherein the wheel (2) of the caster (1) is lockable in rotation relative to a geometrical wheel axis (y) by means of the positive locking brake device (14), wherein, for displacement of the rotational-locking engagement member (43) from a released position into an engagement position, a first spring (58) acts upon the rotational-locking engagement member (43) and is supported on a pivotable lever member (41), characterized in that the first spring (58) forms a lever arm (68) which constitutes part of the first spring (58) and is therefore resilient itself, that upon displacement of the rotational-locking engagement member (43) into the engagement position a second spring (59), supported on the lever member (41), is tensioned for return movement into the released position, and that the first spring (58) is stronger than the second spring (59).

2. The positive locking brake device according to claim 1, characterized in that both the first spring (58) and the second spring (59) are substantially relaxed in the released position.

3. The positive locking brake device according to any one of the preceding claims, characterized in that the first spring (58) is designed as a torsion spring.

4. The positive locking brake device according to any one of the preceding claims, characterized in that the second spring (59) is designed as a torsion spring.

5. The positive locking brake device according to any one of the preceding claims, characterized in that the second spring (59) acts between the lever member (41) and a fork-fixed support portion (45).

6. The positive locking brake device according to any one of the preceding claims, characterized in that the first spring (58) and the second spring (59) each act on the lever member (41) at one end, wherein preferably the first spring (58) acts exclusively between the lever member (41) and the rotational-locking engagement member (43).

7. The positive locking brake device according to any one of the preceding claims, characterized in that the second spring (59) surrounds a support pin (53) of the lever member (41).

8. The positive locking brake device according to any one of the preceding claims, characterized in that the first spring (58) is guided in a groove (65) of the lever member (41).

9. The positive locking brake device according to any one of the preceding claims, characterized in that the lever member (41) comprises two actuation ends (55, 56).

10. Positive locking brake device (14) for a caster (1), comprising a wheel (2), a fork (3), and a rotational-locking engagement member (43),wherein the wheel (2) of the caster (1) is lockable in rotation relative to a geometrical wheel axis (y) by means of the positive locking brake device (14), wherein, for displacement of the rotational-locking engagement member (43) from a released position into an engagement position and / or from the engagement position back into the released position, the rotational-locking engagement member (43) is actuatable via a lever member (41),wherein the lever member (41) is actuatable by means of a plunger member (33), and wherein the plunger member (33) is forkshaped and comprises plunger projections (35, 36) of different lengths, of which only one plunger projection (35, 36) is arranged to act upon the lever member (41), characterized in that the plunger projections (35, 36) extend, in a usual orientation of the caster (1), substantially in a vertical direction, and that the plunger projections (35, 36) extend on both sides of and along a mounting-pin axis of a mounting pin which surrounds a geometrical swivel axis.

11. The positive locking brake device according to claim 10, characterized in that the plunger member (33) is actuatable by a switching plunger (12).

12. The positive locking brake device according to any one of claims 10 or 11, characterized in that the plunger member (33) interacts with a second return spring (42).

13. The positive locking brake device according to any one of claims 10 to 12, characterized in that the switching plunger (12) interacts with a first return spring (19).

14. The positive locking brake device according to any one of claims 12 or 13, characterized in that the second return spring (42) acts directly only on one of the plunger projections (35, 36,and that the other plunger projection (35, 36) is free from direct bias by a return spring, wherein preferably the longer plunger projection (36) comprises a through-opening (69) for the second return spring (42).

15. The positive locking brake device according to any one of claims 10 to 14, characterized in that the mounting-pin axis passes substantially centrally through a U-web of the plunger member (33).