WO2020053827A1

WO2020053827A1 - Hydraulic cartridge for a telescopic saddle post and telescopic saddle post provided with said cartridge

Info

Publication number: WO2020053827A1
Application number: PCT/IB2019/057736
Authority: WO
Inventors: Andrea Chiesa
Original assignee: Yep Components Sagl
Priority date: 2018-09-14
Filing date: 2019-09-13
Publication date: 2020-03-19
Also published as: CH715335B1; CH715335A2

Abstract

A hydraulic cartridge for a telescopic saddle post (1) and a telescopic saddle post (1) comprising the cartridge, wherein the oil and the gas are contained in physically separate chambers.

Description

HYDRAULIC CARTRIDGE FOR A TELESCOPIC SADDLE POST AND TELESCOPIC SADDLE POST PROVIDED WITH SAID CARTRIDGE

The present invention relates to a hydraulic cartridge for a telescopic saddle post (1) and to a telescopic saddle post (1) which comprises said telescopic saddle post cartridge for bicycles and the like.

In the technical field of reference, i.e., cycling, it is known to vary the height of the saddle from the frame as a function of the conditions of use of the bicycle: for example, when traveling downhill it is convenient for the saddle to be lowered (i.e., moved closer to the frame) so as to ensure that the user has maximum maneuverability and backward movement of the body; vice versa, on level ground and uphill the saddle must be returned to an adequate and ergonomic position in order to not hinder the user in the pedaling stroke.

The movement for lowering and lifting the bicycle saddle can be provided by acting on the supporting structure of the saddle itself, commonly known as saddle post, which comprises a telescopic tube which engages in a corresponding tubular seat of the actual frame of the bicycle.

In order to facilitate the maneuvers for lifting and lowering the saddle, adjustable telescopic saddle posts have arisen over time; the adjustment can be obtained mechanically or by means of an actuator (e.g., hydraulic, pneumatic, or mixed).

The purely mechanical solution, for example with springs, while being inexpensive is not entirely satisfactory, since it has a relatively modest functionality and does not lend itself to installation on premium bicycles.

Solutions with an actuator usually comprise a pressurized sealed cartridge connected to the two telescopic tubular portions (one connected to the frame, the other to the saddle) that form the supporting structure of the saddle post; the user, without dismounting from the bicycle, by acting on an appropriate control opens or closes the passages for the oil or gas and causes the rapid lowering or lifting of the saddle. This solution has greater functionality; however, it is not free from limitations. In some known solutions the oil and the gas are contained in the same chamber and are separated only due to the force of gravity as a consequence of which the oil accumulates on the bottom of the chamber; although generally speaking this solution is functional, it however has the drawback that the oil and the gas tend to mix when the bicycle is tilted with respect to the vertical axis (e.g., due to a fall or to transport in a horizontal condition or the like); in this case it is necessary to perform draining in order to restore correct operation.

Another limitation is related to the fact that the cartridges cannot be overhauled by an ordinary user, i.e., the gas and/or the oil cannot be replaced or topped up when necessary.

The gas of the cartridges is in fact contained in a dedicated tank which cannot be accessed from the outside or is accessible only with difficulty or with the aid of specialized workers and/or with special tools.

The aim of the present invention is to provide a cartridge for a telescopic saddle post and a telescopic saddle post comprising said cartridge that is capable of improving the background art in one or more of the aspects indicated above.

Within the scope of this aim, an object of the invention is to provide a cartridge and a telescopic saddle post that can be easily overhauled by a user without requiring specialist interventions.

Another object of the invention is to provide a cartridge and a telescopic saddle post the parts of which can be easily replaced, even individually, in case of malfunction or wear.

A further object of the invention is to provide a cartridge and a telescopic saddle post that are relatively compact, having a modest longitudinal extension.

Furthermore, an object of the present invention is to overcome the drawbacks of the background art in a manner that is alternative to any existing solutions.

Another object of the invention is to provide a cartridge and a telescopic saddle post that are highly reliable, relatively easy to provide and at competitive costs.

This aim, as well as these and other objects which will become better apparent hereinafter, are achieved by a cartridge for a telescopic saddle post according to claim 1 , optionally having one or more of the characteristics of the dependent claims, and by a telescopic saddle post comprising said cartridge according to the corresponding independent claim, optionally having one or more of the characteristics of the claims that depend from it.

Further characteristics and advantages of the invention will become better apparent from the description of a preferred but not exclusive embodiment of the cartridge and of the telescopic saddle post according to the invention, illustrated by way of nonlimiting example in the accompanying drawings, wherein:

Figures 1 and 2 are a side view and a sectional view of a saddle post according to the invention, in a completely retracted condition;

Figures 3 and 4 are a side view and a sectional view of the saddle post of the preceding figures, in a fully extended condition;

Figures 5 and 6 are a side view and a sectional view of the saddle post of the preceding figures, in a partially extended condition;

Figures 7 and 8 are sectional views of the valve of the saddle post of the preceding figures, respectively in the open and closed condition;

Figure 9 is an exploded sectional view of the saddle post of the preceding figures;

Figure 10 is a sectional view of a lower portion of the saddle post of the preceding figures;

Figure 11 is a sectional view of an upper portion of the saddle post of the preceding figures.

With reference to the cited figures, the hydraulic cartridge is designated by the reference numeral 6.

The cartridge 6 is of the type suitable to be installed in a telescopic saddle post 1 of the type that comprises a hollow upper seat tube 2 which is coupled to a saddle supporting assembly 5 and a hollow lower seat tube 3 configured to be coupled to a frame of a bicycle or the like, in which the upper seat tube 2 and the lower seat tube 3 can be engaged telescopically with each other and accommodate said cartridge 6.

The details of the saddle post 1 will be discussed again later on.

Going back now to the cartridge 6, according to the invention, it comprises a cartridge body 63, inside which a first chamber 61 and a second chamber 62 for a hydraulic fluid are provided, and a piston shaft 5 which can move with respect to said cartridge body 63.

The cartridge 6 furthermore comprises a valve 7 which is coupled to the piston shaft 5 and is configured to selectively connect the first chamber 61 and the second chamber 62, in order to enable or interrupt the passage of the hydraulic fluid between them.

As will become apparent hereinafter, according to the invention the first and second chambers 61, 62 have respective variable volumes; preferably, the volumes are variable in an inversely proportional manner, i.e., while the volume of one chamber increases, the other one decreases.

The first and second chambers 61, 62 according to the invention are configured to provide a closed volume for the hydraulic fluid: this means that the total volume of fluid of the cartridge occupies the entire volume of the first and second chambers without gas being contained therein; the volume variation of one chamber therefore entails a transfer of an equivalent quantity of hydraulic fluid into the other chamber, which therefore sees its own volume very accordingly.

The relative motion between the valve 7 and the body 63, in the condition in which the valve 7 is open, entails the volume variation and the transfer of the fluid into one chamber or the other. Preferably, the cartridge 6 comprises a floating piston 10, which can move along the piston shaft 5; the second chamber 62 is partly delimited by the floating piston 10, the function of which will be clarified better hereinafter; for the time being it is sufficient to note that the movement of the floating piston along the piston shaft 5 produces a volume variation of the chamber 62.

Preferably, the first chamber for the oil 61 extends up to a removable closure plug 21; after removing it, it is possible to access the first chamber 61, for example to replace the hydraulic fluid contained therein.

Preferably, according to the invention, the valve 7 comprises a flow control element 72 and an elastic return element 71 which acts on the flow control element 72 in order to keep it stably in a position in which it affects a port for the passage of the fluid between the first chamber 61 and the second chamber 62.

The valve 7, therefore, is intended to enable or interrupt the passage of the hydraulic fluid between the first and second chambers and vice versa.

The flow control element 72 then passes to an open position (in which it connects the two chambers 61 and 62) by means of the application of a contrast force which overcomes the force of the elastic element, for example provided as a spring.

The cartridge preferably comprises a hermetic accommodation chamber 90 in which the elastic return element 71 is accommodated; preferably, the hermetic accommodation chamber 90 is formed by a cap 91.

The chamber 90 contains air; this entails that the contrast force required to bring the flow control element 72 to the open condition depends substantially only on the elastic constant of the elastic return element 71.

This force is applied by means of an actuation element of the valve 7 which extends from the flow control element 72 up to an actuation assembly 73 which is configured to act on the valve 7 in an antagonistic manner with respect to the elastic return element 71. The valve 7 is preferably of the ON/OFF type.

Further additional details of these aspects will be provided hereinafter.

Moving on now to describe the telescopic saddle post according to the invention as a whole, it is designated generally by the reference numeral 1 and comprises a coupled hollow upper seat tube 2 and a hollow lower seat tube 3, which are configured to be mutually engaged telescopically.

The upper seat tube 2 has an end connected to a saddle supporting assembly 50, for example of the type with a double clamp, in which the frame of a bicycle saddle is engaged in the installed condition.

The opposite end of the upper seat tube 2 in this example is engaged inside the lower seat tube 3, the two diameters being compatible for this functionality; in embodiments which are alternative but equivalent from this point of view, the end of the upper seat tube 2 accommodates inside it the lower seat tube 3.

The latter is in turn configured to be coupled to a bicycle frame or the like, for example engaged in a tubular seat with a locking means provided on the frame, which is to be considered per se known, and on which one does not dwell further.

The saddle post 1 accommodates the cartridge 6 for hydraulic fluid of the type described above; in particular, the cartridge 6 is accommodated in the cavity formed by the upper seat tube 2 and the lower seat tube 3, which are hollow.

The cartridge 6 is coupled both to the upper seat tube 2 and to the lower seat tube 3, so that the movement of the upper and lower seat tubes is tied to a relative movement between the body 63 of the cartridge and the valve 7 (moved into a fixed position on the piston shaft 5), with the consequent volume variation of the chambers 61, 62.

Preferably, the piston shaft 5 is coupled to the lower seat tube 3 and the cartridge body 63 is coupled to the upper seat tube 2. The saddle post 1 furthermore comprises a tank 9 for pressurized gas (preferably compressed air), which is advantageously external to said cartridge 6.

Preferably, the pressurized gas tank 9 is provided between the cartridge 6 and at least part of the upper seat tube 2, in the interspace that exists between them.

Going back to the floating piston 10, it separates the second chamber 62 for the hydraulic fluid from the pressurized gas tank 9, so that a movement of the floating piston 10 along the piston shaft 5 entails a volume variation both of the second chamber 62 and of the pressurized gas tank 9.

In the context of the cartridge 6, the chamber 61 is located in a first upper cartridge portion 68 while the second chamber 62 is located partly in a second lower cartridge portion 69, as visible in the detail of Figure 9 and partly in the free volume between the valve 7 and the floating piston 10.

For example, by viewing Figure 2 it is possible to notice the saddle post 1 in a fully retracted (minimum length) condition: the first chamber 61 in this case has a minimum volume, while the second chamber 62 has the maximum volume; a diametrically opposite situation is instead provided in the fully extended configuration of Figure 4, wherein the first chamber 61 has the maximum volume while the second chamber 62 has the minimum volume; an intermediate situation is the one of Figure 6.

Preferably, the cartridge portions 68, 69 are substantially cylindrical (or equivalently prismatic) and are coupled to each other.

In the preferred and illustrated embodiment, the cartridge portions 68, 69 have different diameters and are connected by an adapter 67 which blends the different dimensions and at the same time ensures the hermetic fluid tightness of the chambers 61, 62.

The movement of the cartridge 6 with respect to the piston shaft 5 (and therefore with respect to the valve 7) produced by the relative movement of the upper and lower seat tubes (as a consequence of the elongation or shortening of the saddle post 1 , for example in the transition of the saddle post between the conditions of Figures 1 and 2 for elongation and vice versa for shortening) causes the volume variation of the first chamber 61. The valve 7 is in fact connected to the lower seat tube 3 and is fixed with respect to it, while the cartridge 6 is connected to the upper seat tube 2 and is fixed with respect to it: in the shortening or elongation movement of the seat tubes 2, 3, therefore, the cartridge portions 68, 69 translate with respect to the valve 7.

The chamber 62, and therefore the chamber 61, thus vary their respective volume in the shortening or elongation motion.

The volume variation of the chamber 62 is influenced also by the movement of the floating piston 10 with respect to the piston shaft 5.

The floating piston 10 in fact provides a movable wall which separates the second chamber 62 and the tank 9, so that the movement of the floating piston 10 causes a variation of the respective volumes.

Preferably, the tank 9 is formed by walls which comprise at least part of the internal walls of the upper seat tube 2, part of the external walls of the cartridge 6, a centering and sealing plug 15 coupled hermetically to the end of the upper seat tube 2 that is associated with the saddle supporting assembly 5, and the above-mentioned floating piston 10.

The centering and sealing plug 15 separates hermetically the outside environment from the tank 9 in order to ensure that the latter remains pressurized.

For this purpose, furthermore, advantageously there is a filling valve 16, which is preferably coupled to the upper seat tube 2 and is functionally connected to the tank 9 and by means of which a pressurized gas, for example compressed air, can be sent to the tank 9 or by means of which the latter can be discharged (by opening the valve 16, the gas contained in the tank 9 discharges into the outside environment until equalization of the pressure between the environment and the tank occurs). In other equivalent embodiments, the valve 16 is provided on the centering and sealing plug 15, so that in case of malfunction it is possible to replace the entire plug together with the filling valve 16.

Advantageously, as clearly shown in Figure 11 , the first chamber for the oil 61 extends up to a corresponding closure plug 21 which is coupled to the first cartridge portion 68 and on which a filling channel 17 is provided which in turn is closed by a second plug 18 which is coupled to the closure 21.

The closure plug 21 and the end of the first cartridge portion 68 are engaged on the centering plug 15, which is also provided with a protection element 22, also in the form of a plug, which opens and closes a passage of the centering plug 15 which is aligned with the closure plug 21.

In this manner, by removing the protection element 22 and the closure plug 18 it is possible to empty/fill with hydraulic fluid (oil) the first chamber 61 and, by keeping the valve 7 open, also the second chamber 62: the maintenance procedure which provides for the replacement or topping up of the oil in the cartridge 2 is thus simplified.

As a whole, therefore, maintenance of the saddle post is facilitated: even an ordinary user can autonomously replace/change both the pressurized gas and the oil of the cartridge 2 quickly and by acting without removing the saddle post 1 from the bicycle.

Going back now to the valve 7 which, coupled to the end of the piston shaft 5, separates or connects the chambers 61 and 62, said valve is shown in the detailed view of Figures 7 and 8 in the open and closed positions respectively.

Preferably, as mentioned earlier, the stable position is the closed one (Figure 8).

This is achieved by virtue of the elastic return element 71, such as a return spring or a an elastomer, which acts on the flow control element 72, pushing it into a position for closing the oil passages provided in the valve body, which (when open) connect the chambers 61 and 62.

The spring 71 ensures high reliability in operation and is not affected by any decreases of the pressure of the gas in the tank; however, in alternative embodiments the spring 71 can be replaced with a different but equivalent elastic means.

For the actuation of the flow control element 72 there is furthermore an element for the actuation of the valve 7 which preferably comprises an actuation rod 77 which is accommodated inside the piston shaft 5 and extends from the flow control element 72 of the valve 7 to the actuation assembly 73, which is associated with the lower seat tube.

The actuation assembly 73 is shown in detail in Figure 10 and acts in an antagonistic manner with respect to the return spring 71 , so as to actuate the opening of the flow control element 72. The actuation assembly 73 is actuated by the user, by virtue of actuation means which can be of different types, for example mechanical (such as cable-operated or hydraulic ones) or actuated electrically (such as those with an electric actuator or the like), and are not shown in detail.

In the embodiment shown, the actuation assembly 73 comprises a cam 75 which is coupled to the rod 77 and to an actuation lever 76, so as to push the rod 77, and therefore the flow control element, into a condition for opening the oil passages between the chambers 61 and 62, overcoming the antagonistic force of the spring 71.

Moving on now to the floating piston 10, it moves in the second portion 69 of the cartridge 6, along the shaft 5.

The primary function of the piston 10 is to compensate the difference in transverse cross-section that exists between the first chamber 61 and the second chamber 62, which is determined by the fact that while the first chamber 61 is (in transverse cross-section) substantially empty, the second chamber 62 accommodates inside it the piston shaft 5, which in addition to supporting the valve 7 accommodates inside it the actuation rod 77. During the longitudinal shortening of the saddle post, a portion of the oil volume contained in the first chamber 61 passes (by virtue of the open valve 7) into the second chamber 62; due to the piston shaft 5 that is present in this chamber, the volume available in the two chambers for an equal axial movement is different; this causes the axial movement of the floating piston 10 along the piston shaft 5 in the direction away from the valve 7, which is necessary in order to recover the volume of the second chamber 62 that is occupied by said piston shaft 5.

Since the floating piston 10 separates the variable volume gas tank 9 from the second chamber 62, accordingly the volume available for the gas in the tank decreases, with a consequent compression of the gas; the pressure of the gas in the tank 9 accordingly rises; as shown hereinafter, in order to cause the shortening it is necessary to open the valve 7 and apply to the upper seat tube such a force as to overcome the force produced by the pressure of the gas on the floating piston 10.

When instead the saddle post 1 is extended, the pressure of the gas in the tank 9 acts on the floating piston 10 and causes its movement toward the valve 7 (which is open), with a consequent volume reduction of the chamber 62 and therefore (since the hydraulic fluid is substantially incompressible) the passage of the fluid into the first chamber 61; as will become apparent hereinafter, this motion for return to the extended condition of the saddle post 1 is automatic, in that it is sufficient for the user to open the valve 7 and remove the load on the first seat tube 2 in order to obtain the extension movement.

Moving on now to describing the operation of the telescopic saddle post according to the invention, it is as follows.

When the saddle is in the stable raised or partially raised or extracted position (Figures 2, 3), the upper seat tube 2 and the lower seat tube 3 are at least partly extracted from each other and the valve 7 is kept in the closed condition by the corresponding return spring 71; the passage of the hydraulic fluid between the first chamber 61 and the second chamber 62 is therefore inhibited. The user can thus load his own weight on the saddle, for example by sitting and pedaling, and the saddle remains in position due to the fact that the hydraulic fluid cannot pass from one chamber 61, 62 to the other.

When the user wishes to lower the saddle, he actuates the actuator 73 by means of which the rod 77 acts on the flow control element 72 of the valve 7, opening the passages between the chambers 61, 62; the user then applies a certain force to said saddle downward (i.e., a force applied to the upper seat tube and directed from there toward the lower seat tube); for example, the user remains sitting on the saddle and thus applies thereto his own weight. This produces a shortening motion of the saddle post and a retraction of the upper seat tube 2 into the lower one 3 ; since the cartridge 2 is connected to the upper seat tube 2, accordingly the motion produces a reduction in volume of the first chamber 61, the oil of which passes, through the valve 7, which is open, into the second chamber 62.

The pressure of the gas in the tank (preferably approximately 10 bar in this condition) that acts on the floating piston 10 is not sufficient to withstand the force applied by the user and therefore an increase in the volume of the second chamber 62 is determined and occurs both by virtue of the movement of the portion 69 with respect to the valve and by virtue of the movement of the floating piston 10, which compresses the gas of the tank 9, reducing its volume.

When the user releases the actuator for opening the valve 7, the chambers 61 and 62 close, inhibiting the passage of the oil, and the saddle post returns to a stable condition.

When the user wishes to extend the saddle post in order to return the saddle to a raised position, it is sufficient for him to remove his own weight from the saddle (for example by standing on the pedals, without dismounting from the bicycle) and actuate the opening of the valve 7: the pressurized gas 9, by acting on the floating piston 10, moves it toward the second chamber 62; the oil contained in the latter is free to pass through the valve 7 into the first chamber 61, with a consequent reduction in volume of the second chamber 62 and an increase of the first chamber 61.

This increase in volume of the first chamber 61 displaces upward (i.e., toward the saddle) the upper seat tube 2, which is thus partly extracted from the lower seat tube 3, with a consequent elongation of the saddle post and, ultimately, return of the saddle to the raised position.

Once the desired saddle position has been reached, the user releases the actuation of the valve 7, which again passes to the closed condition, inhibiting the passage of oil between the chambers and restoring the desired stable position to the saddle post.

It should be noted that preferably the transverse area of the first chamber 61 is smaller than that of the second chamber 62; if the cartridge comprises cylindrical bodies 68, 69, as in the illustrated example, the diameter of the first chamber 61 is smaller than the diameter of the second chamber 62, so as to obtain a cartridge that as a whole has modest longitudinal dimensions.

In practice it has been found that the invention achieves the intended aim and objects, providing a telescopic saddle post that is simple to maintain and easy to use.

The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the inventive concept; all the details may furthermore be replaced with other technically equivalent elements.

In practice, the materials used, as well as the contingent shapes and dimensions, may be any according to the requirements and the state of the art.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. A hydraulic cartridge (6) for a telescopic saddle post (1) of the type comprising a hollow upper seat tube (2) coupled to a saddle supporting assembly (50) and a hollow lower seat tube (3) configured to be coupled to a bicycle frame or the like, wherein the upper seat tube (2) and the lower seat tube (3) can be mutually engaged telescopically and accommodate said cartridge (6),

said cartridge (6) being characterized in that it comprises

a cartridge body (63), inside which a first chamber (61) and a second chamber (62) for a hydraulic fluid are provided,

a piston shaft (5), which can move with respect to said cartridge body (63)

a valve (7) which is coupled to the piston shaft (5) and is configured to selectively connect the first chamber (61) and the second chamber (62), in order to enable or interrupt the passage of the hydraulic fluid between the first and second chambers and vice versa

said first and second chambers (61, 62) having respective variable volumes,

said first and second chambers (61, 62) being configured to provide a closed volume for the hydraulic fluid.

2. The hydraulic cartridge (6) according to claim 1, characterized in that it comprises a floating piston (10) which can be moved along said piston shaft (5), wherein said second chamber (62) is delimited partly by the floating piston (10).

3. The hydraulic cartridge (6) according to claim 1 or 2, characterized in that the first chamber for the oil (61) extends to a removable closure plug (21).

4. The hydraulic cartridge (6) according to one or more of the preceding claims, characterized in that the valve (7) comprises a flow control element (72) and an elastic return element (71) which acts on the flow control element (72) in order to keep it stably in a position in which it close a port for the passage of the fluid between the first chamber (61) and the second chamber (62).

5. The hydraulic cartridge (6) according to the preceding claim, characterized in that it comprises a hermetic chamber (90) for the accommodation of said elastic return element (71).

6. The hydraulic cartridge (6) according to claim 4 or 5, characterized in that it comprises an element for the actuation of the valve (7) which extends from the flow control element (72) of the valve (7) to an actuation assembly (73) which is configured to act on the valve (7) in an antagonistic manner with respect to the elastic return element (71).

7. A telescopic saddle post (1), comprising:

- a hollow upper seat tube (2), coupled to a saddle supporting assembly (50),

- a hollow lower seat tube (3), configured to be coupled to a bicycle frame or the like,

the upper seat tube (2) and the lower seat tube (3) being mutually engageable telescopically,

characterized in that it comprises a hydraulic cartridge (6) according to one or more of the preceding claims, the piston shaft (5) of which is coupled to the lower seat tube (3) and the cartridge body (63) of which is coupled to the upper seat tube (2).

8. The telescopic saddle post (1) according to the preceding claim, characterized in that it comprises a pressurized gas tank (9) which is external to said cartridge (6).

9. The telescopic saddle post (1) according to claim 7 or 8, characterized in that said pressurized gas tank (9) is provided between said cartridge (6) and at least part of the upper seat tube (2).

10. The telescopic saddle post (1) according to one or more of claims 7 to 9, characterized in that the floating piston (10) separates the second chamber (62) for the hydraulic fluid from the pressurized gas tank (9), so that a movement of the floating piston (10) along the piston shaft (5) corresponds to a volume variation of said second chamber (62) and of said pressurized gas tank (9).

11. The telescopic saddle post (1) according to one or more of claims

8 to 10, characterized in that it comprises a centering and sealing plug (15) which is coupled hermetically to the end of the upper seat tube (2) that is associated with the saddle post assembly (5) and is configured to form a wall of said pressurized gas tank (9).

12. The telescopic saddle post (1) according to one or more of claims

8 to 11, characterized in that it comprises a filling valve (16), which is functionally connected to the pressurized gas tank (9) in order to send/discharge to/from the tank (9) a volume of gas.