DE9320268U1 - Seat post - Google Patents

Description

17.01.94 Su/Ka/Mu
G2294

Benn-Gürlevik & Partner GmbH. D-7000 Stuttgart 40

Seat post

State of the art

The invention relates to a seat post of a height-adjustable saddle for devices such as bicycles, exercise bikes and the like according to the type of the main claim.

In a known seat post of the generic type (DE-OS 35 36 012), the support rod can be fixed for two different heights of the saddle, i.e. for two different axial positions between the support rod and the guide tube, using a rotatable latch. The drive in the extension direction is via a gas spring tube, in the opposite direction by the weight of the person sitting on the saddle. This locking mechanism, which also serves as a control device, also prevents a relative rotation between the support rod and the

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Guide tube and can be operated via a cable from the longitudinal rod. The gas spring tube is arranged inside the telescope and is therefore protected against mechanical influences.

Such gas spring tubes are commercially available and have a working piston on which the lifting rod can be arranged on one side. Usually there are surfaces of different sizes on the two front sides of this working piston, namely a continuous surface and an annular surface (lifting rod side), whereby the gas chambers on both sides of the piston can be connected to one another via a valve. An additional coil spring creates a pressure difference in the two chambers. When the valve is open, the piston and thus also the lifting rod can be moved in the direction of the lifting rod, or it can also be moved in the other direction by overcoming the appropriate force. As soon as the valve is then closed again, the chambers on both sides of the piston are also closed and form a gas spring, i.e. the piston rod is air-sprung due to the piston being stretched between airtight chambers. The gas spring tube therefore has both a spring effect between the piston rod and the spring bearing acting on the casing tube and the possibility of an axial change in length between the end of the lifting rod and the casing tube of the gas spring tube, which can be controlled via the valve and after which the gas suspension is maintained when the valve is closed. Of course, there are a wide variety of designs for such gas spring tubes.

In another known seat post (DE OS 2900 780) the gas spring tube itself serves as a support rod, whereby the lifting rod extending downwards from the gas spring tube is directly connected to the frame tube via a corresponding device. Depending on the operation of the valve and depending on the axial load, the entire gas spring is

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The saddle attached to it is pushed up or down in the frame tube.

The disadvantage of this known seat post lies primarily in the direct use of the gas spring tube as a telescopic tube, since even minor damage, such as dents in the casing tube, leads to damage to the inner radial sliding surface of the piston, with the risk that the two gas pressure chambers on either side of the piston are connected to one another even when the valve is closed, and as a result the saddle is always moved to its maximum high position in an undesirable manner, which can be associated with considerable practical disadvantages when returning it back. In addition, the rider is constantly burdened by the saddle tending upwards, not to mention that the saddle again undesirably moves to its lower end position when the person puts pressure on it.

A further disadvantage is that additional devices can only be attached to a limited extent to such a sensitive component as the gas spring tube, not to mention the fact that there is a constant friction connection between the jacket tube of the gas spring tube and the guide tube, which can lead not only to wear but also to an increase in the temperature of the gas and thus to a change in the intended working values. There is also the risk of damage to the gas spring tube, e.g. by kinking, which can lead to an explosive discharge of the gas tube.

Advantages of the invention

The seat post according to the invention with the characterizing features of the main claim has the advantage over the generic seat post mentioned at the beginning that

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In addition to the drive by the gas spring tube for the height adjustment, the spring effect of the gas spring tube is retained, quite apart from the fact that the control device acts directly on the valve arranged in the gas spring tube, so that a prior relief of the locking point as with the generic seat support is not necessary. In addition, this locking control device is also arranged in a protected manner and can be individually designed, both via a manual intervention option arranged in the area of the saddle and via a remote control from a longitudinal rod. A decisive advantage is also that the support rod is designed as a support tube, since any additional mass (weight) is a considerable disadvantage, especially when the invention is used for bicycles.

But the other known seat post mentioned above (DE-OS 29 00 780), which allows for height adjustment and suspension of the saddle, also has disadvantages that are overcome primarily by the following advantages of the invention.

The gas spring tube is completely arranged inside the telescopic tube and is therefore protected against external damage and stress. In addition, no sliding fit between the gas spring tube and the guide tube is required. While it is extremely difficult to accommodate a relative rotation lock in the known seat post, since the diameter of the gas spring tube is almost completely the same as the inside diameter of the guide tube for reasons of radial space, in the design according to the invention the support tube can be secured against rotation in a variety of ways during its lifting movement relative to the guide tube. In this way, the seat cannot rotate relative to the

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Vehicle frame is guaranteed - in contrast to the known design. As can be seen from the patent literature, there is a large number of documents available, especially for bicycle seat posts. A seat post from 1937 is known in particular (DE-PS 651 151), in which the height of the seat can be adjusted while driving using a Bowden cable and which has a spring effect. However, this seat post cannot achieve the kind of damping that is possible with gas springs, nor is there a gas spring at all. If one wanted to compare this object, which works with hydraulic means, with a gas spring, the main disadvantage here would be that the clamp is also attached directly to this "gas spring" with the disadvantages mentioned above, and that the entire device is relatively heavy. Last but not least, the use of sufficiently strong coil springs requires a minimum diameter, which brings with it the disadvantages mentioned in terms of anti-twisting. As is well known, of the many proposals for spring-loaded, damping or height-adjustable seat posts, none has yet been introduced to the market due to the problems demonstrated by the advantages of the invention.

According to an advantageous embodiment of the invention, the gas spring tube is arranged in the support tube and engages the guide tube on the piston side. A piston rod can be used for this, which can be attached to the bottom of the guide tube, for example by screwing. In particular, compared to the second known seat post mentioned (DE-OS 29 00 780), the entire seat post can be pulled out of the frame tube of a bicycle or device, and the gas spring tube is protected accordingly against external influences. Similar to this known seat post, the valve is on the side of the gas spring tube facing away from the piston rod.

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arranged so that easy access is possible from the control device, which can be arranged, for example, in the saddle clamp.

According to an alternative advantageous embodiment of the invention, the gas spring tube is arranged on the side of the guide tube facing away from the saddle and engages the support tube on the piston side. For this purpose, a corresponding bushing for absorbing the piston forces can be arranged on the side of the support tube facing away from the saddle.

According to an advantageous embodiment of the invention, the lifting rod of the gas spring tube is firmly connected to the support tube via a nipple. In this way, both tensile and thrust forces are transferred directly from the gas spring tube to the support tube, whereby the gas spring tube can be fastened in the guide tube. Normally, a screw option is provided on the side of the gas spring tube facing away from the lifting rod in order to screw the latter to the base of the guide tube.

According to a further advantageous embodiment of the invention, a valve rod accessible from the front side of the lifting rod is provided coaxially in the gas spring tube in the lifting rod, with a control rod that works axially with the valve rod being mounted in the support tube so that it can move axially and is adjustable by the actuating device. Seeger rings that can be placed on appropriately provided ring grooves in the control rod can be used to guide the control rod radially in the support tube.

According to a further advantageous embodiment of the invention, the valve of the gas spring tube can be actuated from the direction of the saddle. This allows

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Advantageously, some of the implementation elements of the control device are arranged in the saddle clamp.
According to a further advantageous embodiment of the invention, the actuating device for the valve system has a lever which is pivotably mounted in the area of the saddle clamp, so that the person who wants to adjust the height only has to briefly reach under the saddle in order to carry out the height adjustment, for example while driving.

According to a further advantageous embodiment of the invention, the actuating device has a cable pull (Bowden cable), which can be actuated in particular from the handlebar.

According to a further advantageous embodiment of the invention, the actuating device is equipped with hydraulic means, in particular for amplifying other control variables, which interact with the cable pull or with the mechanical lever device or even with a hydraulic pressure transmission system. According to a corresponding embodiment for this purpose, a stepped blind bore is present in the saddle clamp, in the section with a larger diameter the support tube is conically fastened and the section with a smaller diameter accommodates a hydraulic piston which can be acted upon by oil under pressure, which can be fed via a stop bore in the saddle clamp.

According to a further advantageous embodiment of the invention, balls serve as anti-twisting devices between the guide tube and the support tube, which are radially mounted on the one hand in hemispherical recesses of one tube and on the other hand are guided in longitudinal grooves with a semicircular cross-section of the other tube.

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According to a further advantageous embodiment of the invention, as an anti-twist device between the guide tube and the support tube, the guide tube has a polygonal cross-section on its inside and at least on the end face facing the saddle, for example in the form of a guide bush, whereby the support tube guided in the guide bush has a corresponding polygonal cross-section on its outside. In this way, the support tube is guided with a minimum of frictional resistance with its edges on the inner surface of the guide tube and is secured against twisting by the polygon, for example the bush connected to the guide tube. A preferred embodiment here is the hexagonal cross-section. However, other forms of anti-twist device are also conceivable, for example with longitudinal beads that engage in corresponding grooves.

According to a further advantageous embodiment of the invention, interlocking longitudinal grooves or longitudinal elevations are provided between the anti-rotation tube and the support tube as an anti-rotation device. This takes into account, in particular, any tubes that may be present as standard, such as those available on the market for internal wedges.

According to a further advantageous embodiment of the invention, a bellows sleeve covering the free telescopic section of the support tube is provided between the guide tube and the support tube or saddle clamp. This sleeve prevents dirt from getting into the guide surface between the guide tube and the support tube.

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A further advantage of the invention is that the spring force in the gas spring can be adjusted or switched off completely.

Further advantages and advantageous embodiments of the invention can be found in the following description, the drawings and the claims.

drawing

Three embodiments of the subject matter of the invention are shown in the drawing and described in more detail below.
Show it:

Fig.l a seat post in longitudinal section as first

Embodiment operated by a lever;

Fig.2 is a section along line I-I in Figure 1;

Fig.3 Section along the line H-II in Figure 1;

Fig.4 is a section along the line III-III in Figure 1;

Fig.5 the second embodiment in longitudinal section,
with hydraulic actuation;

Fig. 6 is a section along the line IV-IV in Figure 5;

Fig.7 is a section along line V-V in Figure 5;

Fig.8 the third embodiment in longitudinal section

Fig.9 a section along line VI - V in Fig. 8 and

Fig.10 a section along line VII - VII in Fig. 8

Description of the execution examples

In the first embodiment shown in Figure 1, a guide tube 2 is inserted into a bicycle frame 1 and secured in the usual way with a lever clamping screw 3

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clamped. A gas spring tube 4 is anchored axially in the guide tube 2, the lifting rod 5 of which is connected to a support tube 6 on the side facing away from the gas spring tube 4. The support tube 6 is mounted axially displaceably in the guide tube 2 and is secured against twisting relative to the guide tube 2 by balls 7.

As can be seen particularly in Figure 2, these balls 7 are mounted in hemispherical recesses 8 arranged in the outer surface of the support tube 6 and guided in longitudinal grooves 9 with a semicircular cross-section provided in the inner wall of the guide tube 2. This allows the support tube 6 to be axially displaced in the guide tube 2 and at the same time secured against twisting. This is necessary because the saddle (not shown) is attached to the support tube 6 via a saddle clamp 11, which should not normally be twistable relative to the bicycle frame 1, unless it is a matter of pre-adjusting the saddle, although this is done by turning the guide tube in the frame 1 before the guide tube is then tightened using the rotary clamping screw. The longitudinal grooves 9 in the guide tube 2 are easier to see in Figure 3, since when the seat post is adjusted as shown in Figure 1, the lifting rod 5 and thus the support tube 6 are almost completely extended. In Figure 4, the section through the gas spring tube 4 is also shown, although the internal structure of this gas spring tube is not shown, but rather only shown as hatching.

The height adjustment of the saddle is carried out via a valve arranged in the gas spring tube 4, which is controlled by a valve rod 12, which is mounted coaxially in the lifting rod 5 (Figure 3) and can be actuated via a control rod 13 and a lever 14 mounted in the saddle clamp 11. As soon as the

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When the valve rod 12 is pushed downwards, two gas chambers in the gas spring tube 4 are connected to one another, so that the separating piston located there can be moved by the lifting rod 5. From the end position shown, the saddle can thus be pushed back down before the valve in the gas spring tube 4 is locked after the lever 14 is released and the set position is locked. Due to the specific function of the gas spring, the saddle springs up or down from this set position. As soon as the valve is opened, the lifting rod 5 pushes the saddle upwards due to the function given to such gas spring tubes, or due to external force or weight, the lifting rod 5 can be pushed into the gas spring tube 4 accordingly while simultaneously lowering the saddle.

In the second embodiment shown in Figures 5 to 7 and the third in Figures 8 to 10, individual components are designed differently, which is why functionally identical parts are designated with the same reference numbers as in Figures 1-3, but each increased by 100 or 200. The bicycle frame is also not shown in Figure 5, but the guide tube 102 is clamped into the bicycle frame in the same way as the guide tube 2 in Figure 1 or 202 in Figure 8.

The gas spring tube 104 is attached to the base 16 of the guide tube 102 via a screw 15. The lifting rod 105 can hardly be seen in this illustration, since it is almost completely retracted into the gas spring tube 104. The lifting rod 105 is here firmly screwed to the support tube 106 via a screw nipple 17. The valve rod 112 is actuated by a control rod 113, on the side of which facing away from the valve rod 112 a hydraulic piston 18 is arranged, which can be acted upon by hydraulic oil in a blind bore 19, which is fed via a feed bore 21

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The control rod 113 is guided radially via spring rings 22 on the inner wall of the support tube 106, which can be pushed onto corresponding annular grooves in the outer surface of the control rod 113. The saddle clamp 111 is, as in the first embodiment, wedged onto the end of the support tube 106 via a cone.

A guide bush 23, which is attached to the end of the guide tube 102 and has a hexagonal inner recess 24, serves as an anti-twisting device. The support tube 106, which is also hexagonal in its outer dimensions, is guided in this inner recess 24 with little play and slides with its edges on the inner wall of the guide tube 102 in its lower section.

The guide bush and the support tube can also have other suitable cross-sections to prevent rotation.

A bellows sleeve 25 is arranged between the cylindrical section of the saddle clamp 111 and the guide bush 23. Otherwise, this second embodiment works like the first, apart from the actuating device, which is hydraulic here.

In the third embodiment shown in Figure 8, the same reference numbers are again used, which are increased by 100 compared to the second embodiment.

In contrast to the first two embodiments, here the gas spring tube 204 is reversed, i.e. arranged in the support tube 206. A clamping ring 26 serves to lock it, the lifting rod 206 is attached to the base 16 of the guide tube 202 via nuts 27. A built-in rubber disk 28 serves as end position damping. The valve rod 212 is here on the side of the

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Gas spring tube 204 and interacts directly with the hydraulic piston 18 in the saddle clamp 211. Otherwise, this seat post works in the same way as the previously described ones.
All features presented in the description, the following claims and the drawings can be essential to the invention both individually and in any combination with one another.

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Reference number list

1, 201 202 Frame 2, 102, Guide tube 3, 203 204 Twist clamp screw 4, 104, 205 Gas spring tube 5, 105, 206 Lifting rod 6, 106, Support tube 7 Balls 8th hemispherical recess 9 Longitudinal grooves 10 211 - 11, 111, 212 Saddle clamp 12, 112, Valve rod 13, 113 Control rod 14 lever 15 screw 16 Floor 17 Screw nipple 18 Hydraulic piston 19 Blind hole 20 - 21 To guide bore 22 Spring ring 23 Guide bush 24 Inner recess 25 Bellows cuff 26 Clamp ring 27 Nuts 28 Rubber ring

Claims (16)

&PSgr; m · m * 17.01.94 Su/KaMu G 2294 Benn-Gürlevik & Partner GmbH, D-7000 Stuttgart 40 Seatpost Claims 1. Seat post from a height adjustable Saddle for equipment such as bicycles, exercise bikes, etc. - with a guide tube (2, 102, 202) which can be inserted into a frame tube (1, 201) that is open at the front and can be clamped there, - with a support rod (6, 106, 206) which is mounted in the guide tube (2, 202, 206) so as to be axially displaceable, forms a telescope with it and is secured against relative rotation, and at the end of which facing away from the guide tube (2, 102, 202) a saddle clamp (11, 111, 211) is arranged, to which the saddle can be fastened, and - with a gas spring tube (4, 104, 204) which is arranged inside the telescopic tube, on the casing side or piston side, on the one hand on the guide tube (2, 102, 17.01.94 Su/Ka/Mu
G2294 202) and on the other hand on the support rod (6, 106, 206) for adjusting the height of the saddle, and with a control device for height adjustment
characterized, - that the support rod is tubular in shape as a support tube (6, 106, 206), - that the telescopic tube consisting of the support tube and guide tube with the gas spring tube (4, 104. 204) acts as a spring element for the saddle, - that a valve (12, 112, 212) of the gas spring tube (4, 104, 204) that can be operated at will by an actuating device (13, 14, 18, 19, 113) is present as a control device for the height adjustment, and - that an interlocking longitudinal profile between the inside of the guide tube (2, 102, 202) and the outside of the support tube (6, 106, 206) serves to protect against relative rotation. 2. Seat post according to claim 1, characterized in that the gas spring tube (204) is arranged in the support tube (206) and engages the guide tube (202) on the piston side. 3. Seat post according to claim 1, characterized in that the gas spring tube (4, 104) is arranged on the side of the guide tube (2, 102) facing away from the saddle and engages the support tube (6, 106) on the piston side. 4. Seat post according to claim 3, characterized in that the lifting rod (105) of the gas spring tube (104) is firmly connected to the support tube (106) via a nipple (17). 17.01.94 Su/Ka/Mu
G2294 5. Seat post according to claim 3 or 4, characterized in that the gas spring tube (4, 104) is firmly connected coaxially in the lifting rod (17) to the support tube (106). 6. Seat post according to one of the preceding claims, characterized in that the valve can be actuated with the valve rod (12, 112, 212) of the gas spring tube (4, 104, 204) from the side of the saddle clamp (11, 111, 211). 7. Seat support according to one of the preceding claims, characterized in that the actuating device has a lever (14) which is pivotally mounted in the region of the saddle clamp (11). 8. Seat post according to one of claims 1 to 6, characterized in that the actuating device has a cable pull (Bowden cable) which can be actuated from another location, in particular the longitudinal rod. 9. Seat post according to one of the preceding claims, characterized in that the actuating device is equipped with hydraulic means (18, 19, 21), in particular for amplifying other control variables. 10. Seat post according to claim 9, characterized in that in the saddle clamp (111, 211) there is a stepped blind bore (19), in the section of larger diameter the support tube (106, 206) is conically fastened, and the section (19) of smaller 17.01.94 Su/Ka/Mu
G2294 diameter accommodates a hydraulic piston (18), and that this bore section (19) has a hydraulic bore (21). 11. Seat post according to one of the preceding claims, characterized in that as an anti-twist device between the guide tube (2) and the support tube (6) is conically fastened and the section of smaller diameter (19) thereof accommodates a hydraulic piston (18), and that this bore section (19) has a hydraulic connection bore (21). 12. Seat post according to one of claims 1 to 10, characterized in that as an anti-twist device between the guide tube (102, 202) and the support tube (106, 206) the guide tube (102, 202) has a mercantile cross-section on the inside (24) and at least on the end face facing the saddle (guide bushing 23), and that the support tube (106, 206) has a corresponding multi-cornered cross-section in its guide area on its outside. 13. Seat post according to one of claims 1 to 10, characterized in that interlocking longitudinal grooves or longitudinal elevations are provided between the guide tube and the support tube as an anti-twisting device. 14. Seat post according to one of the preceding claims, characterized in that a bellows sleeve (25) covering the free telescopic section of the support tube (106, 206) is provided between the guide tube (102, 202) and the saddle clamp (111, 211). 17.01.9 4 Su/Ka/Mu
G2294 15. Seat post according to one of the preceding claims, characterized in that the spring force in the gas spring tube is adjustable. 16. Seat post according to claim 15, characterized in that the spring force can be switched off completely.