GB1592077A - Creación de Inventos y Patentes con Inteligencia Artificial

GB1592077A – Multi-speed hub for a bicycle
– Google Patents

GB1592077A – Multi-speed hub for a bicycle
– Google Patents
Multi-speed hub for a bicycle

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Publication number
GB1592077A

GB1592077A
GB49392/77A
GB4939277A
GB1592077A
GB 1592077 A
GB1592077 A
GB 1592077A
GB 49392/77 A
GB49392/77 A
GB 49392/77A
GB 4939277 A
GB4939277 A
GB 4939277A
GB 1592077 A
GB1592077 A
GB 1592077A
Authority
GB
United Kingdom
Prior art keywords
gear
hub
shaft
teeth
pawl
Prior art date
1976-11-27
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)

Expired

Application number
GB49392/77A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)

Shimano Inc

Original Assignee
Shimano Industrial Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
1976-11-27
Filing date
1977-11-28
Publication date
1981-07-01

1976-11-27
Priority claimed from JP14278076A
external-priority
patent/JPS5366640A/en

1976-11-27
Priority claimed from JP14277976A
external-priority
patent/JPS5366639A/en

1977-11-28
Application filed by Shimano Industrial Co Ltd
filed
Critical
Shimano Industrial Co Ltd

1981-07-01
Publication of GB1592077A
publication
Critical
patent/GB1592077A/en

Status
Expired
legal-status
Critical
Current

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Classifications

B—PERFORMING OPERATIONS; TRANSPORTING

B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS

B62M—RIDER PROPULSION OF WHEELED VEHICLES OR SLEDGES; POWERED PROPULSION OF SLEDGES OR SINGLE-TRACK CYCLES; TRANSMISSIONS SPECIALLY ADAPTED FOR SUCH VEHICLES

B62M11/00—Transmissions characterised by the use of interengaging toothed wheels or frictionally-engaging wheels

B62M11/04—Transmissions characterised by the use of interengaging toothed wheels or frictionally-engaging wheels of changeable ratio

B62M11/14—Transmissions characterised by the use of interengaging toothed wheels or frictionally-engaging wheels of changeable ratio with planetary gears

B62M11/16—Transmissions characterised by the use of interengaging toothed wheels or frictionally-engaging wheels of changeable ratio with planetary gears built in, or adjacent to, the ground-wheel hub

Description

PATENT SPECIFICATION
p ( 11) ( 21) Application No 49392/77 ( 22) Filed 28 Nov 1977 ( 19) ( 31) Convention Application Nos 51/142780 ( 32) Filed 27 Nov 1976 in 51/142779 ( 33) Japan (JP) ( 44) Complete Specification published 1 July 1981 ( 51) INT CL 3 F 16 H 3/54 B 62 M 11/16 ( 52) Index at acceptance F 2 D 2 B 2 2 Cl A 2 CI Bl 2 C 1 B 2 2 Cl C 2 C 3 B 2 C 4 B 1 2 D 5 2 D 7 ( 54) A MULTI-SPEED HUB FOR A BICYCLE ( 71) We, SHIMANO INDUSTRIAL COMPANY LIMITED, a corporation organized and existing under the laws of Japan, of 77, 3cho, Oimatsu-cho, Sakai-shi, Osaka, Japan, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and
by the following statement:-
The invention relates to a multi-speed hub for a bicycle, this hub being provided with a coaster brake.
A conventional multi-speed hub provided with a coaster brake comprises a shaft fixable to a bicycle frame, a driving member rotatably mounted on the shaft so as to be rotatable thereabout in a forward or an opposed rearward direction, a hub shell encircling the shaft and rotatable thereabout relative to the driving member, a multi-speed gear assembly housed within the hub shell and capable of transmitting torque from the driving member to the hub shell, and a brake assembly capable of braking rotation of the hub shell about the shaft when the driving member is rotated in the rearward direction about the shaft The driving member is rotated in either the forward or rearward direction by the bicycle chain as the cyclist pedals in the appropriate direction; when the driving member rotates forwardly, torque is transmitted from the driving member in the gear assembly to the hub shell, whilst when the driving member is rotated rearwardly, the brake assembly brakes rotation of the hub shell.
In such a conventional hub, the gear assembly comprises a sun gear mounted on the shaft, a gear frame bearing at least one planet gear meshed with the sun gear, and a ring gear having teeth engageable with the planet gear(s); torque from the driving member may be transmitted via either the gear frame or the ring gear to the hub shell by means of pawls engaged with ratchet teeth provided on a radially-inward surface of the hub shell However, if when the driving member is rotated rearwardly to brake the hub shell the cyclist continues to back-pedal until the bicycle stops, the pawls are then held locked in mesh with the ratchet teeth, and the driving member tends to «lock», that is to say it cannot be rotated in either direction immediately after the cyclist ceases to back-pedal because the pawls are locked in mesh with the ratchet teeth, so that the brake assembly continues to co-act with the hub shell and thereby prevents the driving member rotating Locking of the driving member also occurs if the bicycle is pushed backward, because the pawls then actuate the brake assembly by rotating the gear frame in the rearward direction about the shaft.
It has been proposed to overcome this locking problem by providing in the hub a control ring which is in frictional contact with the hub shell and which will urge the pawls radially-inwardly towards the shaft during braking, so disengaging the pawls from the ratchet teeth Alternatively, it has been proposed to use a so-called «ratchetidling» hub in which the ratchet teeth are provided on a member separate from the hub shell and capable of rotating freely relative thereto through a limited arc In such a ratchet-idling hub, when the cyclist begins to pedal forward again after braking, the pawls and the member bearing the ratchet teeth rotate together through the said limited arc, so disengaging the brake assembly from the hub shell.
Both the control ring hub and the ratchetidling hub have the disadvantage that they require the presence of an extra, separate member in the very limited space within the hub shell, which complicates manufacture and assembly of the hub The control ring hub has the additional disadvantage that its reliance on frictional contact between the 1592077 1,592,077 control ring and the hub shell renders it unreliable in operation and that locking may still occur if the bicycle is pushed backwards.
The present invention seeks to overcome, S or at least substantially alleviate, the aforementioned disadvantages of prior art multispeed coaster brake hubs and to provide a hub which is not of unduly complicated construction and which does not suffer from locking during braking or when the bicycle is pushed backwards.
Accordingly, the invention provides a multi-speed hub comprising a shaft; a driving member rotatably mounted on the shaft so as to be rotatable thereabout in a forward or an opposed rearward direction; a hub shell encircling the shaft and rotatable thereabout relative to the driving member; a multi-speed gear assembly housed within the hub and comprising a sun gear mounted on the shaft, a gear frame bearing at least one planet gear engageable with the sun gear, a ring gear having teeth engageable with the planet gear(s), and a clutch cone screwthreadedly engageable with the gear frame and capable of axial movement relative to the shaft; a control member capable of transmitting torque from the driving member to the gear assembly; a brake assembly capable of braking rotation of the hub shell about the shaft when the driving member is rotated in the rearward direction about the shaft, the brake assembly comprising at least one brake shoe and a brake cone, such that upon the said axial movement of the clutch cone in one direction relative to the shaft, the brake and clutch cones will force the brake shoe(s) to co-act with the hub shell, thereby braking the hub shell; first teeth and second teeth both disposed on a radially-inward surface of the hub shell; at least one first and at least one second transmission member engageable with the first and second teeth respectively so that the first and second teeth can transmit torque from the gear assembly to the hub shell, the first transmission member comprising at least one pawl biased away from engagement with the first teeth but capable of being moved into engagement therewith when the driving member is rotated about the shaft in the forward direction and the gear assembly causes the gear frame and the ring gear to rotate at different angular velocities about the shaft, and the gear assembly being capable of transmitting torque from the control member to the first and second transmission members at any one of a plurality of differing gear ratios when the driving member is rotated about the shaft in the forward direction.
In the hub of the invention, preferably the second transmission member has the form of a ring bearing on a radially-outward surface thereof teeth engaged with the second teeth on the hub shell and having a radially 70 outward surface thereof in contact with the clutch cone, a clutch means being disposed between the second transmission member and the gear frame, the clutch means being such that it will transmit torque from the hub 75 shell to the fear frame when the former is rotated in the rearward direction about the shaft but will slide relative to the gear frame or the second transmission member when the resistance to rotation of the gear frame 80 exceeds a predetermined value.
In this specification, the terms «axial» and «radial» are used to mean axial and radial respectively with respect to the shaft, and terms such as «radially-outward» are to be 85 construed accordingly.
A preferred embodiment of the invention will now be described in more detail, though by way of illustration only, with reference to the accompanying drawings, in which: 90 Figure 1 is a part cut-away front elevation of a multi-speed hub of the invention; Figure 2 is an enlarged front elevation of the part of the hub shown in Figure 1; and Figures 3 and 4 are helf-sections along the 95 lines III-III and IV-IV respectively in Figure 2.
The hub of the invention shown in the accompanying drawings is a three-speed hub having high, middle and low gear ratios The 100 hub comprises a shaft 1, a driving member 3, a hub shell 5, a three-speed gear assembly (generally designated 6), a control member 7 and a brake assembly (generally designated 8) The shaft 1 is fixed to the rear forks F of a 105 conventional bicycle frame and has fixedly mounted on its central portion a sun gear 2 which forms part of the gear assembly 6 The shaft is provided at its opposed axial ends with screw threads 11 and 12 The screw 110 thread 11 (on the right-hand side of the hub in Figures 1 and 2) engages a corresponding thread on a ball holder 13, which is provided with a ball race Balls 14 are held between this ball race and a further ball race provided 115 on a radially-inward surface of the driving member 3, so mounting the driving member 3 rotatably on the shaft 1 The screw thread 11 also engages a threaded lock nut 15 which serves to secure the shaft I to the adjacent 120 rear fork F of the bicycle frame The other thread 12 on the shaft I engages both a corresponding thread on a brake cone 81, forming part of the brake assembly 8, and a lock nut 16 which holds the hub in its correct 125 position relative to the other rear fork F of the bicycle frame.
The driving member 3 has fixedly mounted on its radially-outward surface a sprocket 4, this sprocket being held in 130 1,592,077 position by a snap ring held in a groove in the said radially-outward surface The sprocket 4 engages the chain (not shown) of the bicycle and as the cyclist pedals in the forward or rearward directions, the sprocket 4 causes the driving member 3 to rotate about the shaft 1 in a forward or an opposed rearward direction A ball race is also provided on the radially-outward surface of the driving member 3, whilst on the radiallyinward surface of the member 3 are cut axially-extending splines 31.
The hub shell 5, which encircles the shaft 1, is provided on its radially-inward surface, adjacent its opposed axial ends, with a pair of ball races; a set of balls 17 are held between one of these ball races and the ball race on the radially-outward surface of the driving member 3, whilst a further set of balls 18 are held between the other ball race on the hub shell 5 and a ball race provided on the radially-outward surface of the brake cone 81 The balls 17 and 18 render the hub shell 5 rotatable about the shaft 1 independently of the driving member 3.
On its radially-outward surface, the hub shell 5 bears a pair of flanges 51 and 52 having apertures therethrough into which wheel spokes can be inserted, whilst on its radially-inward surface the hub shell 5 bears first and second ratchet teeth 53 and 54 respectively.
The three-speed gear assembly 6 is capable of transmitting torque from the control member 7 to first and second transmission members (see below) at any one of its three differing gear ratios when the driving member 3 is rotated about the shaft 1 in the forward direction, and is housed within the hub shell 5 The gear assembly 6 comprises, besides the sun gear 2, a gear frame 62 bearing a plurality of planet gears 61 meshed with the sun gear 2, a ring gear 64 having on its radially-inward surface teeth 63 meshed with the planet gears 61, and a clutch cone 82 One axial end (the left-ward end in Figures 1 and 2) of the gear frame 62 is provided with a tubular extension 621 which has on its radially-outward surface a coarse screw thread engaged with a corresponding screw thread on the clutch cone 82; this screw-thread engagement between the gear frame 62 and the clutch cone 82 renders the latter axially-movable relative to the shaft 1.
On a radially-inward surface at the opposed axial end of the gear frame 62 are cut teeth 622 engageable with end teeth 71 provided on the control member 7 Adjacent the teeth 622 on the gear frame 62 is an annular stepped portion 623.
The ring gear 64 bears two first transmission members, having the form of high and medium-speed transmission pawls 20 engageable with the first teeth 53 on the hub shell 5 A second transmission member in the form of a clutch ring 65 bearing on its radiallyoutward surface teeth 651 permanently in mesh with the second teeth 54 on the hub shell 5 is formed separately from the gear frame 62 and supported on the clutch cone 70 82 as may be seen in Figs 1 and 2 The pawls are accommodated in and extendathrough two diametrically-opposed apertures 644 in the ring gear 64 and the radially-inward faces of the pawls 20 abut the stepped portion 623 75 of the gear frame 62 Also, the ring gear 64 is slidable axially of the shaft 1 and is biased away from the driving member 3 by a helical spring 66 disposed between the two members On a radially-inward surface at the 80 axial end of the ring gear 64 nearer the driving member 3 are cut teeth 641, which are engageable with the end teeth 71 on the control member, and shoulders 642 at the left-hand axial ends (in Figures 1 and 2) of 85 the teeth 641; these shoulders 642 can abut the adjacent axial end faces of the end teeth 71 Finally, in the radially-outward surface of the ring gear 64 adjacent the stepped portion 623 of the gear frame 62 is cut a 90 groove 643 (see Figure 3) which accommodates a circular pawl spring 21 This pawl spring 21 co-acts with the pawls 20 so as to bias the tips thereof radially-inwardly away from engagement with the first teeth 53 and 95 keep the radially-inward surfaces or bases of the pawls 20 abutted against the stepped portion 623 of the gear frame 62.
The pawls 20 are provided with a pawl control means capable of forcing the tips of 100 the pawls radially-outwardly against the bias of the pawl spring 21 under certain conditions; this pawl control means comprises a hollow cylindrical casing 22 and two rollers 23 The casing 22 encircles the stepped 105 portion 623 of the gear frame 62 and is retained in position by the bent end of a clutch spring 24 (see Figure 3) which is accommodated in an annular groove 623 a formed in the stepped portion 623 The 110 casing 22 is provided with two apertures 221 therethrough, these apertures each accommodating one of the rollers 23 and part of one of the pawls 20 As described in more detail below, under certain conditions when 115 the cyclist is pedalling in the forward direction (and hence the driving member 3 is rotating in the same direction about the shaft 1), the ring gear 64 rotates about the the shaft I with a greater velocity than the gear frame 120 62 Under these conditions, the casing 22 is forced by the clutch spring 24 to rotate with the gear frame 62, whereas the pawls 20 are rotating with the greater angular velocity of the ring gear 64, thereby forcing the tips of 125 the pawls radially-outwardly from the position shown in broken lines in Figure 3 to that shown in solid lines therein and engaging the tips of the pawls 20 with the first teeth 53 on the hub shell 5 The pawls 20 then serve to 130 1,592,077 transmit torque from the gear assembly 6 to the hub shell 5 The strength of the circular spring 24 is of course chosen so that it can apply to the rotation of the casing 22 a resistance of such magnitude that the force exerted by the rollers 23 on the pawls 20 is sufficient to overcome the bias applied to the pawls 20 by the pawl spring 21.
On the other hand, if the ring gear 64 is rotated in the rearward direction with an angular velocity greater than that of the gear frame 62, the pawls 20 move along the apertures 221 away from the rollers 23 and since the pawls are no longer urged radiallyoutwardly by the rollers 23, the pawls move radially-inwardly under the bias of the pawl spring 21 and cease to engage the first teeth 53.
Other forms of pawl control mechanism may be substituted for that shown provided they make use of a difference in angular velocity between the gear frame and the ring gear to force the first transmission member(s) into engagement with the first teeth.
Besides the teeth 651 on its radiallyoutward surface, the clutch ring 65, which constitutes the second transmission member and which is separate from the gear frame 62, is provided on a radially-inward surface thereof with a frusto-conical face 652 which contacts a correspondingly-formed face 822 on the clutch cone 82 A second clutch spring 67 is wound around a radially-outward surface of the clutch ring 65 adjacent the gear frame 62 and (as best seen in Figure 4) one end of this spring 67 is bent so as to be engaged in a recess in the gear frame 62.
When the hub shell 5 is rotated in the rearward direction (as for example when the bicycle is pushed backwards), because the second teeth 54 on the hub shell 5 are meshed with the teeth 651 on the ring 65, the ring 65 also rotates in the rearward direction: this causes the spring 67 to tighten around and become fixed with respect to the ring 65 and the bent end of the spring 67 causes the gear frame 62 to rotate rearwardly with the ring 65.
The form of second transmission member employed in the illustrated embodiment of the invention prevents the brake assembly 8 from braking the bicycle when the bicycle is pushed backwards Although such braking action is somewhat undesirable, it is not a serious problem and if desired the ring 65 and the spring 67 may be replaced by lowspeed transmission pawls provided on the gear frame 62, as in a conventional coaster brake hub If such low-speed pawls are employed, they should be of a similar construction to the pawls engageable with the first teeth and mesh with the second teeth 54 only when there is a difference in angular velocity between the gear frame 62 and the ring gear 64.
The brake assembly 8 is of a conventional type and comprises the brake cone 81 and a plurality of brake shoes 83 The brake cone 81 has a frusto-conical face 811, the clutch cone 82 has a frusto-conical face 821, whose 70 radius decreases in the opposed direction to that of the face 811, and each brake shoe 83 has oppositely-inclined faces 831 and 832 respectively Axial movement of the clutch cone 82 to the left in Figures 1 and 2 causes 75 the adjacent pairs of faces 821, 831 and 811, 832 to co-act with each other, thus forcing the brake shoes 83 radially-outwardly into contact with the hub shell S and thereby braking the rotation of the hub shell S about 80 the shaft 1.
The control member 7, which is capable of transmitting torque from the driving member 3 to the gear assembly 6, can be moved axially of the shaft 1 by means of a gear 85 change assembly (generally designated 9).
This gear-change assembly 9 comprises a body member 91 which bears at its opposed axial end members 92 and 93 respectively and which is screw-threadedly engaged with 90 a control rod 10 reciprocable within an axial bore in the shaft 1 The radially-outward parts of the side members 92 and 93 emerge radially from the shaft 1 through apertures therein and are urged by springs 94 and 95 95 respectively into engagement with shoulders provided adjacent the opposed axial ends of the control member 7 When the control rod is moved to the right in Figures 1 and 2, the spring 94 is compressed and the spring 95 100 shifts the side member 93 and the control member 7 to the right; conversely, when the control rod is moved to the left in Figures 1 and 2, the spring 95 is compressed and the spring 94 shifts the side member 92 and the 105 control member 7 to the left.
Finally, the hub shown in the accompanying drawings comprises a pawl holding means in the form of a ring 55 fixedly secured to the radially-inward surface of the 110 hub shell 5 by means of a snap ring accommodated within a groove in that surface As explained in more detail below, under certain conditions the ring 55 holds the pawls 20 in their radially-inward positions 115 (as shown in broken lines in Figure 3).
The operation of the multi-speed hub shown in the accompanying drawings is as follows In Figures 1 and 2, the hub is shown in its high gear-ratio, in which the control rod 120 the body member 91 and the control member 7 are in their extreme left-hand positions The end teeth 71 on the control member 7 engage the teeth 622 on the gear frame 62 and, when the cyclist pedals for 125 wardly, torque is transmitted from the driving member 3 to the control member 7 by means of the splines 31 on the former member, which are permanently meshed with teeth provided on the radially-outward 130 1,592,077 surface of the latter member The control member 7 in turn transmits the torque, via the meshed teeth 71 and 622, to the gear frame 62, which thus rotates about the shaft 1 This rotation of the gear frame 62 about the shaft 1 causes the planet gears 61 to run around the sun gear 2, and the effect of the meshing of the planet gear teeth with both the sun gear teeth and the teeth 63 on the ring gear 64 is that the ring gear rotates about the shaft 1 with a greater angular velocity than the gear frame 62 As explained above, the rotation of the ring gear 64 forwardly (in the direction of arrow X in Figure 3) at a greater angular velocity than the gear frame 62 causes the rollers 23 to force the pawls 20 radially-outwardly against the bias of the spring 21 and into engagement with the first teeth 53, and hence torque is transmitted from the ring gear 64 via the pawls 20 and the first teeth 53 Thus, under these conditions the hub transmits forward torque from the driving member 3 to the hub shell 5 at a high gear ratio.
If the control rod 10 is now moved to the right in Figures 1 and 2 to its central position, the hub adopts its middle-gear ratio The control member 7 moves to the right with the control rod so that the end teeth 71 thereon no longer mesh with the teeth 622 on the gear frame 62 but instead mesh with the teeth 641 on the ring gear 64, which thus rotates at the same angular velocity as the driving member 3 and the control member 7 Since under these circumstances, the gear frame 62 rotates more slowly than the ring gear 64 due to the meshing of the planet gear teeth with both these members, the pawls 20 are held engaged with the first teeth 53 and the hub transmits forward torque at its middle gear ratio from the driving member 3 via the control member 7, the ring gear 64, the pawls and the teeth 53 to the hub shell 5.
When the hub is in either its high or its middle gear-ratio, the meshing of the second teeth 54 with the teeth 651 transmits forward torque from the hub shell S to the ring 65 but since the angular velocity of the hub shell is in both cases greater than that of the gear frame 62, the spring 67 slides relative to the ring 65 and the surfaces 652 and 822 slide over one another so that the rotation of the ring 65 does not interfere with the operation of the hub.
If the control rod 10 is moved still further to the right in Figures 1 and 2, the hub adopts its low gear-ratio: the shift of the control member 7 with the control rod 10 causes the right-hand (in Figures 1 and 2) axial ends of the teeth 71 to abut the shoulders 642 on the ring gear 64, so forcing the ring gear 64 axially to the right This axial movement of the ring gear 64 brings the pawls 20 into contact with the ring 55 which forces the pawls 20 radially-inwardly, thereby disengaging them from the first teeth 53 Forward torque is now transmitted from the driving member 3, via the control member 7 and, the meshed teeth 71 and 641, to the ring gear 64 Under these conditions, the 70 effect of the meshing of the planet gear teeth with both the teeth 63 on the ring gear 64 and the teeth on the non-rotatable sun gear 2 is to rotate the gear frame 62 at a lower angular velocity than the ring gear 64 The gear 75 frame 62 now transmits forward torque to the clutch cone 82 via the engaged screw-threads on the two integers, and the clutch cone 82 in turn transmits the torque via the clutch ring and the meshed teeth 651 and 65 to the 80 hub shell 5 (It will be appreciated that the screw-thread engagement between the gear frame 62 and the clutch cone 82 tends to urge the clutch cone 82 to the right in Figures 1 and 2 and thus increases the reaction be 85 tween the frusto-conical faces 822 and 652 on the clutch cone 82 and the ring 65 respectively Accordingly, although the transfer of torque from the clutch cone 82 to the ring 65 is effected by friction, there is no risk of 90 substantial slippage taking place at this interface) Thus, the hub transmits forward torque from the driving member 3 to the hub shell 5 at the low gear-ratio.
If instead of pedalling forwards, the cyclist 95 back pedals, the driving member 3 rotates in the rearward direction and the gear frame 62 and the ring gear 64 rotate in the same direction (the exact path for transmission of torque from the driving member 3 to the gear 100 frame 62 is the same for rotation in either direction, and depends upon the gear-ratio in use, but whatever the gear ratio, when the driving member 3 rotates in the rearward direction the gear frame will rotate in the 105 same direction and the ring gear 64 will rotate in the rearward direction with a higher angular velocity) This rearward rotation of the gear frame 62 and the interaction between the screw threads on the gear frame 62 110 and the clutch cone 82 forces the clutch cone 82 to the left in Figures 1 and 2 against the bias of a spring which is interposed between the clutch cone 82 and the brake cone 81.
The movement of the clutch cone 81 to the 115 left forces the brake shoes 83 into contact with the hub shell 5 and brakes the hub shell, as explained above Also, as explained above, rearward rotation of the gear frame 62 and faster rearward rotation of the ring 120 member 64 dusengages the pawls 20 from the first teeth 53 so preventing locking of the pawls with the teeth.
Nor can such locking occur if the bicycle is pushed backwards In this case, the hub shell 125 rotates in the rearward direction (in the direction of arrow Y in Figure 3) and rearward torque is transmitted from the hub shell 5 to the ring 65 via the meshed teeth 54 and 651 (and at first via from the hub shell 5 130 1,592,077 to the ring gear 64 via the pawls 20, if the pawls are already engaged with the teeth 53).
The consequent rotation of the ring 65 causes the spring 67 to tighten therearound, whereafter the spring 67 causes the gear frame to rotate in the rearward direction at the same speed as the hub shell S and the ring 65 This rotation of the gear frame 62 causes the ring gear to rotate in the rearward direction with an angular velocity which exceeds that of the hub shell 5 and the gear frame 62, thereby causing the pawls 20 to be disengaged from the teeth 53, as described above.
Under these conditions, the rearward rotation of the gear frame 62 tends to cause the clutch cone 82 to move axially towards the brake shoes 83 but as soon as the clutch cone 82 contacts the brake shoes 83, the resistance to rotation of the gear frame 62 is increased to such a value that the spring 67 slides relative to the ring 65 so that the gear frame 62 ceases to rotate with the ring 65 and the axial movement of the clutch cone 82 is halted before any substantial braking occurs.
It will thus be seen that the preferred embodiment of the invention described above prevents locking of the pawls 20 in engagement with the first teeth 53 during braking or when the bicycle is pushed backwards In the latter case, the hub also prevents any substantial braking taking place The hub is relatively simple in construction.
A multi-speed bicycle hub provided with a coaster brake and producing results in use which are substantially similar to those of the hub of the present invention, but which uses a rotor disposed between a clutch cone and a gear frame, the rotor rotating with a hub shell, is disclosed and claimed in our copending Application No 49393/77 (Serial No 1592078) of even date herewith.

Claims (8)

WHAT WE CLAIM IS:-

1 A multi-speed hub for a bicycle, the hub comprising:
a shaft; a driving member rotatably mounted on the shaft so as to be rotatable thereabout in a forward or an opposed rearward direction; a hub shell encircling the shaft and rotatable thereabout relative to the driving member; a multi-speed gear assembly housed within the hub and comprising a sun gear mounted on the shaft, a gear frame bearing at least one planet gear engageable with the sun gear, a ring gear having teeth engageable with the planet gear(s), and a clutch cone screwthreadedly engageable with the gear frame and capable of axial movement relative to the shaft; a control member capable of transmitting torque from the driving member to the gear assembly; a brake assembly capable of braking rotation of the hub shell about the shaft when the driving member is rotated in the rearward direction about the shaft, the brake assembly comprising at least one brake shoe 70 and a brake cone, such that upon the said axial movement of the clutch cone in one direction relative to the shaft, the brake and clutch cones will force the brake shoe(s) to co-act with the hub shell, thereby braking the 75 hub shell; first teeth and second teeth both disposed on a radially-inward surface of the hub shell; at least one first and at least one second transmission member engageable with the 80 first and second teeth respectively so that the first and second teeth can transmit torque from the gear assembly to the hub shell, the first transmission member comprising at least one pawl biased away from engagement with 85 the first teeth but capable of being moved into engagement therewith when the driving member is rotated about the shaft in the forward direction and the gear assembly causes the gear frame and the ring gear to 90 rotate at different angular velocities about the shaft, and the gear assembly being capable of transmitting torque from the control member to the first and second transmission members at any one of a 95 plurality of differing gear ratios when the driving member is rotated about the shaft in the forward direction.

2 A multi-speed hub as claimed in Claim 1, in which the driving member has a 100 sprocket fixedly mounted thereon.

3 A multi-speed hub as claimed in either of the preceding claims, in which the or each pawl is accommodated within an aperture extending through the ring gear and the bias 105 on the or each pawl causes the radially inward end thereof to abut resiliently the gear frame, the gear frame being provided with a pawl control means such that, when the driving member is rotated in the forward 110 direction about the shaft and the gear assembly adopts a gear ratio which causes the angular velocity of the ring gear about the shaft to exceed that of the gear frame, the pawl control means will cause at least part of 115 the or each pawl to move against the bias radially-outwardly from the shaft and to engage the first teeth.

4 A multi-speed hub as claimed in Claim 3, in which the pawl control means 120 comprises a cylindrical casing having a number of apertures therethrough equal to the number of pawls, the or each aperture being capable of accommodating at least part of one pawl, and in which the hub further 125 comprises a clutch spring capable of applying to the gear frame a force sufficient to enable the gear frame to effect the said radially-outward movement of at least part of the or each pawl, the gear frame remain 130 1,592,077 ing rotatable under said force.

A multi-speed hub as claimed in Claim 4, in which the or each of the apertures through the cylindrical casing houses a roller capable of co-acting with a pawl of which at least part is accommodated within that aperture.

6 A multi-speed hub as claimed in any of the preceding claims, in which the second transmission member has the form of a ring bearing on a radially-outward surface thereof teeth engaged with the second teeth on the hub shell and having a radiallyinward surface thereof in contact with the clutch cone, a clutch means being disposed between the second transmission member and the gear frame, the clutch means being such that it will transmit torque from the hub shell to the gear frame when the former is rotated in the rearward direction about the shaft but will slide relative to the gear frame or the second transmission member when the resistance to rotation of the gear frame exceeds a predetermined value.

7 A multi-speed hub as claimed in any of the preceding claims, further comprising a pawl spring which applies the bias to the pawl(s).

8 A multi-speed hub for a bicycle, the hub being substantially as herein described with reference to and as illustrated in the accompanying drawings.
CRUICKSHANK & FAIRWEATHER, Chartered Patent Agents, 19 Royal Exchange Square, Glasgow G 1 3 AE, Scotland.
Agents for the Applicants.
Printed for Her Majesty’s Stationery Office by Burgess & Son (Abingdon) Ltd -1981 Published at The Patent Office, Southampton Buildings, London, WC 2 A I AY, from which copies may be obtained.

GB49392/77A
1976-11-27
1977-11-28
Multi-speed hub for a bicycle

Expired

GB1592077A
(en)

Applications Claiming Priority (2)

Application Number
Priority Date
Filing Date
Title

JP14278076A

JPS5366640A
(en)

1976-11-27
1976-11-27
Multiispeed hub with coaster brake

JP14277976A

JPS5366639A
(en)

1976-11-27
1976-11-27
Multiispeed hub with coaster brake

Publications (1)

Publication Number
Publication Date

GB1592077A
true

GB1592077A
(en)

1981-07-01

Family
ID=26474674
Family Applications (1)

Application Number
Title
Priority Date
Filing Date

GB49392/77A
Expired

GB1592077A
(en)

1976-11-27
1977-11-28
Multi-speed hub for a bicycle

Country Status (3)

Country
Link

US
(1)

US4147244A
(en)

DE
(1)

DE2752738C2
(en)

GB
(1)

GB1592077A
(en)

Cited By (1)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

DE102005033438A1
(en)

2005-07-18
2007-02-01
Sram Deutschland Gmbh

Braking device for a multi-speed hub

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* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

US4305312A
(en)

1977-06-27
1981-12-15
Lapeyre Fernand S
Bicycle transmission

US4376394A
(en)

1978-12-13
1983-03-15
Lapeyre Fernand S
Manually operable multi-speed bicycle transmission

DE3114381A1
(en)

1981-04-09
1982-11-04
Fichtel & Sachs Ag, 8720 Schweinfurt

DRIVE HUB FOR BICYCLES OR THE LIKE FOR CHAIN GEAR AND WITH A MULTI-SPEED HUB GEAR

DE3440067A1
(en)

1984-11-02
1986-05-07
Fichtel & Sachs Ag, 8720 Schweinfurt

MULTI-GEAR FOR BICYCLES OR THE LIKE

JP3080534B2
(en)

1994-04-28
2000-08-28
株式会社シマノ

Interior transmission

US6019385A
(en)

1997-11-26
2000-02-01
Kelley; Don
Energy storage device for personal vehicle

JP2971862B1
(en)

1998-08-07
1999-11-08
株式会社シマノ

Interior gear hub for bicycle

EP1172291A1
(en)

2000-07-11
2002-01-16
Jen-Chih Liu
Double use inner brake and an inner derailleur for bikes

US6558288B2
(en)

†

2001-05-18
2003-05-06
Shimano, Inc.
Internal transmission device with automatic shift mechanism for a bicycle

DE102005033439B4
(en)

2005-07-18
2014-11-20
Sram Deutschland Gmbh

Multifunctional pen

DE102012200829A1
(en)

2012-01-20
2013-07-25
Sram Deutschland Gmbh

Bicycle transmission, in particular in the form of a multi-gearbox hub

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Priority date
Publication date
Assignee
Title

AT194253B
(en)

1955-11-24
1958-01-10
Fichtel & Sachs Ag

Freewheel and transmission hub with coaster brake for bicycles

US3122226A
(en)

1960-11-04
1964-02-25
Fichtel & Sachs Ag
Three-speed wheel hub with splined ratchet control sleeve

US3366206A
(en)

1965-06-15
1968-01-30
Shimano Industrial Co
Bicycle hub having a built-in three-stage speed change mechanism equipped with a coaster brake

US3608683A
(en)

1968-09-18
1971-09-28
Shimano Industrial Co
Bicycle hub having a built-in three-stage speed change mechanism and equipped with a coaster brake

JPS492736B1
(en)

1970-03-25
1974-01-22

DE2159770C2
(en)

1971-12-02
1983-03-03
Fichtel & Sachs Ag, 8720 Schweinfurt

Multi-speed gear hub

DE2209535C2
(en)

1972-02-29
1974-01-17
Fichtel & Sachs Ag, 8720 Schweinfurt

Multi-speed gear hub with coaster brake

US3973451A
(en)

1974-12-06
1976-08-10
Shimano Industrial Company, Limited
Five speed transmission hub for bicycles

1977

1977-11-17
US
US05/852,346
patent/US4147244A/en
not_active
Expired – Lifetime

1977-11-25
DE
DE2752738A
patent/DE2752738C2/en
not_active
Expired

1977-11-28
GB
GB49392/77A
patent/GB1592077A/en
not_active
Expired

Cited By (1)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

DE102005033438A1
(en)

2005-07-18
2007-02-01
Sram Deutschland Gmbh

Braking device for a multi-speed hub

Also Published As

Publication number
Publication date

US4147244A
(en)

1979-04-03

DE2752738C2
(en)

1986-07-03

DE2752738A1
(en)

1978-06-15

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