Arrangement for actuating a pawl to shift a gear in a bottom bracket gearbox of a bicycle or pedelec.

Abstract

An arrangement for actuating at least one pawl (1) for locking or releasing a rotatable transmission component (2) for shifting a gear in a bottom bracket gearbox (3) of a bicycle or pedelec (4) is proposed, wherein the pawl (1) can be actuated via a first rotatably actuated cam ring (5) to engage a locking tooth (6) of the transmission component (2), wherein the transmission component (2) is associated with at least one band brake (10) which can be actuated via a second rotatably actuated cam ring (7), wherein the first cam ring (5) and the second cam ring (7) each have a cam track (8, 9) along their outer circumference for actuating the pawl (1) and the band brake (10). Furthermore, a bottom bracket gearbox (3) with at least one arrangement and a bicycle or pedelec (4) with the bottom bracket gearbox (3) are proposed.

Description

The present invention relates to an arrangement for actuating at least one pawl for locking or releasing a rotatable transmission component for shifting a gear stage in a bottom bracket transmission of a bicycle or pedelec according to the type defined in more detail in the preamble of claim 1.For example, the document DE 10 2019 220 044 A1 discloses a bottom bracket transmission having an arrangement for actuating at least one brake shift element, wherein the brake shift element comprises an actuatable brake pawl or pawl which, in the closed or engaged state, connects a transmission component to a housing of the bottom bracket transmission. For actuating the brake shift element or the pawl, a rotatably mounted shift drum is assigned to the pawl with a cam track as a shift gate in order to pivot the pawl as a function of the course of the cam track in order to lock or release the transmission component.Further actuating arrangements for ratchets are disclosed in the publications DE 10 2018 212 435 A1 and DE 10 2021 213 506 B3.The object of the present invention is to propose an arrangement for actuating a pawl and a bottom bracket transmission with the arrangement, and a bicycle or pedelec with the bottom bracket transmission, in which a reliable actuation of the pawl is realized, which is improved at least with regard to the shift feeling and the shift acoustics.This object is achieved according to the invention by the subject matter of patent claims 1 or 11 or 12. Advantageous and claimed developments are evident from the dependent claims and the description and the drawings.Thus, an arrangement for actuating at least one pawl for locking or releasing a rotatable transmission component for shifting a gear stage in a bottom bracket transmission of a bicycle or a pedelec is proposed, wherein the pawl can be actuated via a first rotatably actuated cam ring for engaging in a locking toothing of the transmission component. In order to realize a reliable actuation of the pawl, which actuation is improved at least with regard to the shift feeling and the shift acoustics, at least one band brake is assigned to the transmission component, which band brake can be actuated via a second rotatably actuated cam ring, wherein the first cam ring and the second cam ring each have a curved path along their outer circumference for actuating the pawl and the band brake.In the proposed arrangement, the rotational speed of the assigned transmission component can be controlled particularly easily, for example, by the provided band brake, on account of the structurally simple structure, so that, for example, by reducing the rotational speed of the transmission component, reliable engagement of the pawl is made possible, in order to also improve the shift quality with regard to shift feeling and shift acoustics.The band brake in the proposed arrangement has a brake band or the like running around an outer circumference of the transmission component, wherein the brake band is prestressed via a first end and a second end against a brake surface of the transmission component, wherein the first end is arranged in a stationary or stationary manner and the second end of the brake band is operatively connected to the cam path of the second cam ring. Due to the locking toothing provided on the outer periphery, a band brake is suitable as a particularly simple and cost-effective solution, the brake band of which can be brought into operative connection with a brake surface section provided next to the locking toothing for reducing the rotational speed of the transmission component.Various structural designs of the band brake are conceivable in order to use these for braking the transmission component. It is particularly advantageous if the braking surface receiving the brake band runs along the outer periphery of the transmission component in a recess provided centrally on the locking toothing. In this way, the outer circumference of the transmission component can be optimally utilized, on the one hand, for braking by the band brake and, on the other hand, for locking and releasing by the pawl.The connection of the band brake in the proposed arrangement can be realized in various ways. A reliable and qualitatively better actuation of the pawl can be realized in that, due to the operative connection between the cam track of the second cam ring and the second end of the brake band, a tensioning of the brake band around the brake surface of the transmission component or a release of the brake band around the brake surface of the transmission component can be realized in order to control the rotational speed of the transmission component when actuating the pawl.In order to realize synchronous actuation of the pawl and the band brake during the shifting process, it is provided that, on the one hand, an associated end of the pawl is associated with the cam path of the first cam ring and, on the other hand, the band brake is associated with the cam path of the second cam ring in each case in such a way that the transmission component can be locked or released simultaneously by the pawl actuated by the first cam ring and by the band brake actuated by the second cam ring.In the arrangement proposed, separate cam rings each having a cam path can be used. However, it is also conceivable that instead of a cam ring, a rotatably actuated shift roller with a cam contour or cam path is used. It is also possible for a common controlled shift drum having a plurality of cam tracks arranged, for example, next to one another to be used instead of two controlled cam rings.Regardless of the above-described embodiment, it can be provided in the proposed arrangement that the pawl is assigned to the cam path of the first cam ring offset by a predetermined distance along the course of the cam paths with respect to the assignment of the band brake to the cam path of the second cam ring when the first cam ring and the second cam ring are synchronously actuated. The two cam rings can be synchronously controlled or driven, for example, by a common drive. This results in a reliable and simpler actuation of the band brake and the pawl, since only one drive is required for both cam rings. It is also conceivable that instead of the offset assignment of pawl and band brake to the assigned cam paths of the cam rings, a separate actuation of the cam rings is provided.Cam-shaped curves, for example, can be provided as cam tracks on the cam rings. A constructionally simple embodiment provides that the first cam ring and the second cam ring each have a curve path running periodically with maxima and minima.In such a course on the cam tracks of the cam rings or shift rollers, it is provided, for example, that the pawl and the band brake are assigned to the respective cam track offset by a distance along the course of the cam track, wherein the distance corresponds to the distance between a maximum and an adjacent minimum or a multiple thereof.The object on which the invention is based is also achieved by a bottom bracket transmission having at least one arrangement described above. This results in the advantages already described and further advantages.Furthermore, the object on which the invention is based can also be achieved by a bicycle or pedelec with the above-described bottom bracket transmission, wherein the already described and further advantages result.The present invention will be explained further below in the drawings.The following are shown: FIG. 1 shows a three-dimensional view of a possible variant embodiment of an arrangement for actuating a pawl for locking or releasing a transmission component for shifting a gear stage of a bottom bracket transmission of a bicycle or pedelecs; FIG. 2 shows a schematic side view of the arrangement in a released state of the transmission component; and FIG. 3 shows a schematic side view of the arrangement in a locked state of the transmission component.FIGS. 1 to 3 show, by way of example, an embodiment variant of an arrangement for actuating a pawl 1, for example as a brake shift element for locking or releasing a rotatable transmission component 2, for example a ring gear or the like, for shifting a gear stage in a bottom bracket transmission 3 of a bicycle or pedelecs 4, which is likewise indicated only schematically, on the basis of various views.The arrangement shown in FIG. 1 comprises, by way of example, a pawl 1 with which the associated rotatable transmission component 2 can be shifted for shifting the associated gear stage in the bottom bracket transmission 3. It is readily conceivable that a plurality of arrangements for actuating further ratchet pawls 1 are provided in the bottom bracket transmission 3 in order to lock or release further transmission components 2, so that further gears can be shifted in the bicycle or pedelec 4.The pawl 1 can be actuated via a first rotatably actuated cam ring 5 for engaging in a locking toothing 6 of the transmission component 2. For this purpose, the pawl 1 is pivotable in a spring-loaded manner about an axis of rotation between an engaged state and a disengaged state, wherein a first end of the pawl 1 is assigned to the ratchet toothing 6 of the transmission component 2 and wherein a second end of the pawl 1 is assigned to a cam track 8 of a first cam ring 5 for actuating the pawl 1.A band brake 10 is associated with the transmission component 2, which can be actuated via a second rotatably actuated cam ring 7, wherein the first cam ring 5 and the second cam ring 7 each have a cam path 8, 9 along their outer circumference.The band brake 10 has a brake band running around an outer circumference of the transmission component 2, wherein the brake band is prestressed against a brake surface 13 of the transmission component 2 via a first end 11 and a second end 12. The first end 11 of the brake band of the band brake 10 is arranged in a stationary manner or in a stationary manner, for example is fastened to a housing. The second end 12 of the brake band of the band brake 10 is operatively connected to the cam track 9 of the second cam ring 7. Because the brake band of the band brake 10 is prestressed, for example, by means of a tension spring between the first end 11 and the second end 12, the brake band is either tensioned or relaxed by corresponding movement of the second end 12.As can be seen in particular from FIG. 1, the brake surface 13 receiving the brake band runs along the outer periphery of the transmission component 2 in a recess 14 provided centrally on the locking toothing 6.Due to the operative connection between the cam track 9 of the second cam ring 7 and the second end 12 of the brake band, a tensioning of the brake band about the brake surface 13 of the transmission component 2 or a relaxation of the brake band about the brake surface 13 of the transmission component 2 is realized.The second end of the pawl 1 is associated with the cam track 8 of the first cam ring 5, while the second end 12 of the band brake 10 is associated with the cam track 9 of the second cam ring 7, so that the transmission component 2 can be locked or released simultaneously by the pawl 1 actuated by the first cam ring 5 and by the band brake 10 actuated by the second cam ring 7.As can be seen in particular from FIGS. 1 to 3, the cam tracks 8, 9 of the first cam ring 5 and of the second cam ring 7 each have a cam track 8, 9 which runs periodically with maxima or peaks and minima or valleys.In the case of synchronous actuation or synchronous drive of the first cam ring 5 and of the second cam ring 7, it is provided that the second end of the pawl 1 is assigned to the cam track 8 of the first cam ring 5 offset by a predetermined distance along the course of the cam tracks 8, 9 with respect to the assignment of the second end 12 of the band brake 10 to the cam track 9 of the second cam ring 7. This distance corresponds to the distance between a maximum and an adjacent minimum or a multiple thereof.Consequently, in the released state of the transmission component 2 illustrated in FIG. 2 when the pawl 1 is disengaged, it is provided that the second end of the pawl 1 assigned to the cam track 8 of the first cam ring 5 is assigned to a minimum or valley in the course of the cam track 8 of the first cam ring 5, while the second end 12 of the band brake 10 is assigned to a maximum or mountain in the course of the cam track 9 of the second cam ring 7.According to the locked state of the transmission component 2 shown in FIG. 3 when the pawl 1 is engaged, it is provided that the second end of the pawl 1 assigned to the cam path 8 of the first cam ring 5 is assigned to a maximum in the course of the cam path 8 of the first cam ring 5, while the second end 12 of the band brake 10 is assigned to a minimum in the course of the cam path 9 of the second cam ring 7.Reference numerals denote reference numerals1 Ratchet 2 Transmission component 3 Bottom bracket transmission 4 Bicycle or pedelec 5 First cam ring 6 Locking toothing 7 Second cam ring 8 Cam track on the first cam ring 9 Cam track on the second cam ring 10 Band brake 11 First end of the brake band of the band brake 12 Second end of the brake band of the band brake 13 Brake surface 14 Recess centrally on the locking toothing

Claims

Arrangement for actuating at least one pawl (1) for locking or releasing a rotatable transmission component (2) for shifting a gear stage in a bottom bracket transmission (3) of a bicycle or a pedelec (4), wherein the pawl (1) can be actuated via a first rotatably actuatable cam ring (5) for engaging in a locking toothing (6) of the transmission component (2), characterized in that the transmission component (2) is assigned at least one band brake (10) which can be actuated via a second rotatably actuated cam ring (7), wherein the first cam ring (5) and the second cam ring (7) each have along their outer circumference a cam path (8, 9) for actuating the pawl (1) and the band brake (10).Arrangement according to Claim 1, characterized in that the band brake (10) has at least one brake band which extends around an outer periphery of the transmission component (2), wherein the brake band is prestressed against a braking surface (13) of the transmission component (2) via a first end (11) and a second end (12), wherein the first end (11) is arranged in a fixed position and the second end (12) of the brake band of the band brake (10) is operatively connected to the cam track (9) of the second cam ring (7).Arrangement according to Claim 2, characterized in that the braking surface (13) which accommodates the brake band runs along the outer periphery of the transmission component (2) in a recess (14) provided centrally on the locking toothing (6).Arrangement according to Claim 2 or 3 characterised in that, on account of the operative connection between the cam track (9) of the second cam ring (7) and the second end (12) of the brake band, tensioning of the brake band about the brake surface (13) of the transmission component (2) or relaxing of the brake band about the brake surface (13) of the transmission component (2) can be realised.Arrangement according to one of the preceding claims, characterized in that, on the one hand, an associated end of the pawl (1) is associated with the cam track (8) of the first cam ring (5) and, on the other hand, the second end (12) of the band brake (10) is associated with the cam track (9) of the second cam ring (7) in each case in such a way that the transmission component (2) can be locked or released simultaneously by the pawl (1) actuated by the first cam ring (5) and by the band brake (10) actuated by the second cam ring (7).Arrangement according to Claim 5, characterized in that the associated end of the pawl (1) is assigned to the cam track (8) of the first cam ring (5) offset by a predetermined distance along the course of the cam tracks (8, 9) with respect to the assignment of the second end (12) of the band brake (10) to the cam track (9) of the second cam ring (7) when the first cam ring (5) and the second cam ring (7) are actuated synchronously.Arrangement according to one of the preceding claims, characterized in that the first cam ring (5) and the second cam ring (7) each have a curved path (8, 9) running periodically with maxima and minima.Arrangement according to claim 7, characterised in that the associated end of the pawl (1) and the second end (12) of the band brake (10) are associated with the respective cam track (8, 9) offset by a distance along the course of the cam track (8, 9), wherein the distance corresponds to the distance between a maximum and an adjacent minimum or a multiple thereof.Arrangement according to Claim 8, characterized in that, in the blocked state of the transmission component (2) when the pawl (1) is engaged, the associated end of the pawl (1) is associated with a maximum in the course of the cam path (8) of the first cam ring (5) and the second end (12) of the band brake (10) is associated with a minimum in the course of the cam path (9) of the second cam ring (7), and in that, in the released state of the transmission component (2) when the pawl (1) is disengaged, the associated end of the pawl (1) is associated with a minimum in the course of the cam path (8) of the first cam ring (5) and the second end (12) of the band brake (10) is associated with a maximum in the course of the cam path (9) of the second cam ring (7).Arrangement according to one of the preceding claims, characterized in that the pawl (1) can be pivoted in a spring-loaded manner about an axis of rotation between an engaged state and a disengaged state, wherein a first end of the pawl (1) is assigned to the ratchet toothing (6) of the transmission component (2) and wherein a second end of the pawl (1) is assigned to the cam track (8) of the first cam ring (5) for actuating the pawl (1).Bottom bracket transmission (3) with at least one arrangement according to one of the preceding claims.Bicycle or pedelec (4) with a bottom bracket transmission (3) according to claim 11.

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