The invention relates to a height adjustable saddle pole (S) consisting of two tubes which are telescopically slidable into another, that is to say a cladding tube for accommodating a saddle support tube, a spring element acting upon the saddle support tube, a locking device, which is installed on the cladding tube with a locking pin, a guide for the locking pin, means for adjusting the locking pin in a latched position and an unlatched position, whereas the locking pin is moved orthogonally with respect to and in the direction of the axis of the saddle support tube whereas at least two axially spaced apart bores are provided in the saddle support tube for accommodating the locking pin and whereas the locking pin in the latched position engages into one of the bores through a recess of the cladding tube and thus completely absorbs the axial forces of the saddle support tube (16).
Saddle poles for fastening bicycle saddles are usually fixed in the saddle tube with a mechanical clamp. Consequently, the saddle tube is generally slit at the upper end so that the periphery of the tube is reduced by the clamping effect and thus the saddle tube bears upon the saddle pole with a positive fit. The clamp is tightened with a nut or a quick clamping device is used, at which the clamping force is reached by changing the position of a lever. Such a “quick release lever” enables to adjust the height of the saddle and to fix it without tool. Such is for example necessary if the bicycle is going to be ridden by people of different size or if the saddle should be adapted for one and the same rider using certain parameters. Such is the case for instance when riding in difficult terrain, as in particular in mountain biking with mountain bikes. Uphill, the height of the saddle must be adjusted optimally from an ergonomic viewpoint so as to achieve good power transmission. When going downhill, the rider must shift his centre of gravity backwards and downwards according to the steepness and to the difficulty and for that purpose he must often bring his buttocks behind the saddle. The deeper the saddle, the easier the rider can shift his centre of gravity actively and dynamically, but thereby also loses on cornering forces which he can press with the inside of its thighs against the saddle when the latter is accordingly in a raised position The optimal height of the saddle therefore depends on the respective riding condition.
The shortcoming of the described clamping device lies in that the rider must dismount every time he needs to adjust the height and driving direction of the saddle. To make this adjustment easier it is suggested in the German disclosure DE 4237864 A1 to provide a lateral locking pin with which the position in height of the saddle pole can be fixed. This locking pin is however used solely for fixing the height of the saddle pole, whereas conversely the locking mechanism operates in the axial direction and thereby the axial load has conventionally been absorbed by means of a clamping device, hence in a friction locking manner. The rider still needs to dismount for adjusting the height of the saddle pole.
It would hence be desirable to provide a device for adjusting the height of a bicycle saddle, which the rider can adjust without having to dismount.
Height adjustable saddle poles are disclosed in the state of the art which function after the principle of hydraulic locking. The saddle poles described in the German utility model DE 20 2007 014515 U1 (Kindshock) or in the document U.S. Pat. No. 7,083,180 B2 (Paul Turner) operate with two oil chambers which are connected to one another by a valve. A tube can be moved up and down in the shank by opening the valve with the trigger. The lower oil chamber is additionally filled with air so as to generate a force upwards. Consequently the pole is pressed upwards by pulling the trigger and releasing it simultaneously. The trigger is always actuated at the upper end of the saddle support tube via a lever. Said lever can be actuated manually directly on the head of the saddle pole. Alternately, a Bowden cable can be provided from the handlebar for remote actuation of the device via an appropriate mechanism. With the embodiments available on the market at the moment and described above, the adjustment range is currently 125 mm max.
The shortcoming of this pole is the relatively complex structure of the hydraulic system. Furthermore, the hydraulic medium required in the system increases with the adjustment range and so does the weight of the system. An additional shortcoming due to the system is the necessary mounting of the actuating lever on the saddle head. If said lever should be actuated via a remote control on the handlebar the mechanical, hydraulic or electric control cable provided to that end must follow the adjustment stroke of the saddle pole.
A height adjustable saddle pole is disclosed in the international patent application WO 2007/117884 A2 with which a bolt is brought into a recess of a saddle support tube, through a recess of a cladding tube, in a latched position from the outside. The bolt is operated by means of a magnet for adjusting the saddle pole. The mechanism is designed in such a way that the shear force maintains the locking bolt in the locking position as long as the bolt can be loosened by the own weight of the rider. It is hence not possible for example to adjust the height of the saddle pole when the rider is standing on the pedals. Moreover, the mechanism is relatively expensive and the bores are located on the front or on the back in the driving direction, so that the static of the saddle support tube is weakened maximally.
Another mechanical locking is disclosed in document U.S. Pat. No. 6,354,557 B1 (RASE). In that case, a longitudinal groove is inserted into the saddle support tube which also weakens the saddle support tube strongly. The height adjustable saddle pole for a bicycle, disclosed in the German patent specification DE 198 55 161 C1 admittedly has a lateral locking system, but operates with three tubes which are telescopically slidable into another, whereas the tube of the saddle pole has a continuous longitudinal groove in the region of the largest stress, i.e. in the driving direction, which causes maximal weakening of the saddle pole and consequently rules it out for saddle poles with which minimal weight and high mechanical stability are required.
All the height adjustable saddle poles known to the applicant, which operate after the principle of a locking mechanism by means of a locking pin, integrate the bores necessary to that end from the front or from the rear (as seen in driving direction) into the saddle support tube, or exhibit (as the DE 198 55 161 C1 mentioned) additional weaknesses in the area of the largest bending stress. An exception is provided in the German utility model DE 20 2008 015 968 U1, in which the locking is more precisely performed laterally, the locking bolt however engages tangentially with respect to the saddle support tube into an accordingly deepened recess, whereas such bolts are provided with smaller depth between the deepened recesses, into which the accordingly shaped bolt (with two diameters) engages during the height adjustment and hence simultaneously forms an anti-twist device. The tangentially arranged recesses reach further into the region of the increasing bending stress and hence cause more significant weakening compared with simple bores, they are also more difficult to realise than the latter from a manufacturing technical viewpoint.
If the bores necessary to the locking mechanism or recesses of other types are incorporated in the front or rear area of a saddle support tube as seen in driving direction—this is here (relative to the mechanical stability of such a construction) the most inappropriate position for these recesses, since the bending stresses induced by the operational forces reach a maximum in this area. Tests have however shown that with the materials known at the moment and rationally usable for saddle support tubes, which first and foremost with mountain bikes must meet the requirements in terms of robustness, lightweight and operational stability, the saddle pole is weakened by the bores to thet extent that the tube may break or buckle. The weakening of a saddle pole grows exponentially when the recesses are located on the front or on the back, compared to recesses located laterally. With a targeted adjustment stroke of more than 150 millimetres the current tests for saddle poles of mountain bikes, developed by testing agencies, are not passed with such a construction in which the recesses are located on the front or on the back. These tests are performed with simulation of the forces prevailing during riding. It should be noted that the saddle pole is not clamped or fixed in a friction locking manner any longer with these systems, but in fact the load is only absorbed by the locking mechanism in direction of the axis of the saddle pole or of the saddle support tube. The saddle support tube is not fixed any longer in the transition region between saddle support tube and cladding tube.
The object of the invention is hence to remedy the shortcomings aforementioned.
Another purpose of this invention is to provide a pole which is of simple design and easy to maintain, and which allows for adjustment ranges with a lift of more than 150 mm.
The invention should besides provide a solution for a remote control cable running parallel on the cladding tube.
The object is satisfied in that the bores for accommodating the locking pin are located in the area of the smallest stress of the saddle support tube. In the context of the patent application, the term “bore” should be understood as a recess, i.e. it need not strictly be a circular hole but also other geometrical recesses can be provided, for example also conical recesses and/or blind hole-shaped recesses, etc. In the context of the patent application, by “region” is meant that the centre of a bore or recess need not exactly coincide with a point of the neutral fibre, but that it is important to arrange the recesses in regions which do not weaken the saddle support tube so much.
The stress in a saddle support tube is generated by the load of the rider, whose weight force pushes the saddle support tube backwards and downwards. This is due to the fact that the saddle tube (this is the tube of the bicycle which receives the saddle pole) extends obliquely from the receiving opening of the saddle pole forwards and downwards to the bottom bracket bearing. The tensile stress is therefore maximum in the front fibre of the saddle support tube in the driving direction (the compressive stress is accordingly maximum in the rear fibre in the driving direction). The “neutral” fibre of a saddle support tube lies laterally offset by nearly 90 degrees from the maximally stressed fibres. The region of the neutral fibre is hence the region of the smallest stress and hence the optimal region for mounting the locking device.
Due to the bending load, the saddle support tube and hence the bore of the saddle support tube move marginally backwards (indications such as “backwards”, “forwards”, “laterally” are always related to the driving direction), so that the latched locking pin under load is pushed in this direction. It is hence advantageous that the locking pin in the latched position accompanies the movement of the saddle support tube more or less in the direction and in the opposite direction of the cross product of the vector of the longitudinal axis of the cladding tube with the vector of the longitudinal axis of the locking pin. The degree of freedom of the locking pin can be achieved through suitable mounting of the locking pin or its guide.
According to a further advantageous embodiment of the invention, the locking pin has a first flattening or phase in the peripheral area of its front end. The locking pin can hence be latched in the bore more easily.
It is particularly advantageously if the locking pin in the partial regions of its periphery, on which the bores of the saddle support tube have the largest relative movement with respect to the locking pin, contains second larger flattenings so that latching is then secured when the deflection of the saddle support tube is maximum.
It is further advantageous if the contour of the locking pin on its front end matches the contour of the saddle support tube. The locking pin lies thereby already over its surface on the saddle support tube and can hence be brought in the latched position faster, not to mention the release which is also facilitated. All the more so if implemented in combination with the flattenings.
According to a further advantageous variation of the invention, the locking pin is arranged in such a way that it absorbs the load in direction of the longitudinal axis of the cladding tube (28) or of the saddle support tube over its surface in its guide. In the axial direction, the locking pin must absorb almost the whole weight force of the rider. The force should therefore be absorbed flatly as far as possible, preferably by a plane surface area.
The locking pin can hence advantageously be brought into the latched position and into the unlatched position. It is hence meaningful since the force which has to be exerted can be transformed with a lever.
The locking pin should consequently allow the movement of the bore which is caused by the load of the saddle pole.
In a further advantageous embodiment of the invention, the adjustment of the locking pin is done via a slotted guide mechanism. Such a mechanism allows on the one hand to achieve a particularly small design and on the other hand the distance-force curve can be set up and optimised via the design of the sliding path.
The size of the structure of the whole device can be reduced particularly advantageously in such a way that a portion of the mechanism for actuating the locking pin is arranged around the periphery of the cladding tube.
In an advantageous variation of the invention, the locking mechanism is actuated via a Bowden cable. According to the state of the art, shifters or similar actuating devices are provided for actuating such a Bowden cable, which can be fixed to the handlebar of a bicycle, so that the rider can release the height adjustment mechanism during riding. By reversing the actuation of the latching mechanism for example, by means of a curved disc, it is possible to bring the Bowden cable close to the cladding tube or the saddle tube from below, so that it does not interfere with the rider.
An advantageous variation of the invention consists in that the spring element acting upon the saddle support tube is a pneumatic spring. This enables to achieve a relatively flat spring characteristic and a practically constant extension force as well. Such pneumatic springs are commercially available at low cost.
In a further advantageous embodiment of the invention, the cladding tube is the saddle tube of a bicycle. There is consequently no need for an additional tube as a cladding tube and the design of the device can be easier. The saddle tube should indeed be prepared “in factory” accordingly.
According to another advantageous embodiment of the invention, means should be provided to prevent any twisting of the saddle support tube with respect to the cladding tube. This substantially facilitates the adjustment for the rider while riding, since otherwise the saddle might easily be twisted during the adjustment and the locking pin would not latch.
An advantageous variation of the invention consists in that a pinhole closure is provided for sealing the bores which opens in reaction to the force of the locking pin 61. This prevents the ingress of dirt through the bores.
It is further advantageous that the upper end of the external tube of the pneumatic spring or gas spring is fixed at the upper end of the saddle support tube. This hence prevents the saddle pole from falling out or being removed completely. This enables moreover to define the end stop of the maximum extended position of the saddle support tube, which is also adjustable in height through the setting of the pneumatic spring.
An advantageous variation of the invention consists finally in that a wiping device is provided, which contains a felt ring 3. This prevents the ingress of dirt. The felt ring can be soaked with oil so that the saddle support tube is coated with a thin oil film due to the up and down movement and thus absorbs less dirt. Better sliding properties can thus also be obtained.
An exemplary embodiment of the invention is described below using drawings. Wherein:
The locking device V, to which the saddle support tube 16 is fixable relative to the cladding tube, is installed at the upper end of the cladding tube 28. The locking device V can hence be formed in one piece, but it can be installed as a separate component on the cladding tube 28 for example by gluing. The Bowden cable 30 is fastened at the bottom of the locking device V. The locking device V is provided with the cover 5 of the base body GK.
The locking pin 61 is received by the guide 52 via the roller 8. The tilting lever 6 is articulated at the axle 65 of the locking pin 61. The axles 66 of the tilting lever 6 are received in a recess 71 of the base body GK via the rollers 7. The whole pin consists more advantageously of a high performance plastic, which on the one hand meets the requirements in terms of solidity and on the other hand has good sliding properties as regards its guiding means.
The Bowden cable holder 27 is mounted on the right side of the base body GK by means of the fastening screws 271. The Bowden cable holder 27 forms a cavity together with the base body GK, which serves as a guide for the slotted slider 9. It also receives the Bowden cable 26. The slider 273 is actuated via the Bowden cable 26 and engages with its roller 272 into the slotted guide 91 of the slotted slider 9.
The plastic bush 23 enables the saddle support tube 16 to slide in the cladding tube 28 easily. It also absorbs the radial forces of the saddle pole. The pre-wiper ring 1 is screwed on the clamping nut 4 and hence fixes the wiper ring 2 and the felt ring 3. The clamping nut 4 itself is screwed on the cladding tube 28 and hence fixes the plastic bush 23.
The section D-D shows a pinhole closure 22, whose three-dimensional representation is shown in
The exploded drawing according to
The pneumatic spring outer tube of the pneumatic spring GF (
The illustrated parts are listed below in the list of reference numerals.
Number | Date | Country | Kind |
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10 2010 044 356.5 | Sep 2010 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP11/04203 | 8/20/2011 | WO | 00 | 3/1/2013 |