A portion of the disclosure of this patent document contains material which is subject to copyright protection. This patent document may show and/or describe matter which is or may become trade dress of the owner. The copyright and trade dress owner has no objection to the facsimile reproduction by anyone of the patent disclosure as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright and trade dress rights whatsoever.
This patent claims priority from European Patent Application No.: 25153511.8 filed Jan. 23, 2025 entitled “QUICK CONNECT CHAIN TENSIONER FOR BICYCLES AND BICYCLE TRAINERS” and U.S. provisional patent application Ser. No. 63/624,021 filed Jan. 23, 2024 (which is incorporated herein by reference in its entirety) and entitled “QUICK CONNECT CHAIN TENSIONER FOR BICYCLES AND BICYCLE TRAINERS.”
This disclosure relates to exercise devices such as stationary bicycles and bicycle trainers and, more particularly, to a quick connect chain tensioner for cycling exercise devices and bicycle trainers.
There exist various types of exercise devices, many of which provide resistance to increase the intensity of the exercise. For example, dedicated indoor cycles and road cycles fixed to training devices (so-called “trainers”) enable a user to control or implement systems whereby resistance is added to the pedals by any number of methods to train the user to achieve an increase in endurance, power, and speed.
Some systems rely upon manual addition of resistance through gearing, the application of a fixed brake, or even wind-based resistance (e.g., blower-style flywheels on wheels of old-style exercise cycles). More complex systems began enabling computer control of electronic resistance devices in the 1980s and 1990s. These systems typically enabled users to ride through pre-programmed courses of simulated hills and flats and valleys with the associated increases and decreases in resistance controlled by a computer controller. Modern users can virtually experience these changes in terrain via a display that appears to show the user navigating through a particular virtual or real-world course.
These electronic controlled resistance devices are typically magnetic combined with a small or sometimes large flywheel. The most realistic feeling trainers and bicycles typically utilize large flywheels to simulate the mass of the rider and bike. Even more modern resistance devices rely almost exclusively on carefully controlled electromagnets. They do spin, so in some sense they can act as flywheels, but virtually all of the added resistance and momentum is simulated by software through electromagnetic application of current on the spinning axle. These systems are sufficiently sophisticated that they can simulate abrupt changes in gearing typical of road bicycles with many-geared cassettes using a single gear.
A bicycle trainer is a piece of equipment that enables a user to ride a bicycle while the bicycle remains stationary, for example, inside when riding conditions outside are not favorable. Direct drive smart bicycle trainers require a user to remove the rear wheel of the bicycle and place the bicycle on the trainer. A direct drive trainer typically includes a frame, a device to hold the connected bicycle (or bicycle frame) securely, and a mechanism that provides resistance when the pedals are turned, such as a flywheel or an electromagnetic resistance system. The direct drive trainer acts as a replacement for the rear wheel, and is used with a matching cassette, so that the user can shift gears during the simulated ride. This creates a potential barrier to users wishing to begin the process of using the trainer in the process of mounting the bicycle or bicycle frame. Specifically, the process of mounting the bicycle or bicycle frame to the trainer can require users to wrestle with or otherwise manage a chain tensioner that holds the chain tightly around the axle and the cassette for the bicycle.
Traditional bicycles use cassettes that incorporate a plurality of gears. Seven, eight, ten and twelve gears on a cassette are common, but other configurations are also used. Derailleur systems used with these cassettes typically incorporate chain tensioners to ensure that any slack in a chain (required to enable the chain to move from a low gearing to a high gearing which are quite different in diameter) is taken up and the teeth of the cassette gears remain engaged with the chain. Some system to maintain tension in the chain is necessary because as the gearing changes, the amount of the chain used by the gear changes as well. However, these chain tensioners are designed to always function and exert a tension force against the chain to keep it in place. This makes sense because bicycles operate on roadways, hit bumps, are jostled, or are otherwise moved about and a rider generally has no desire to unexpectedly lose tension in a chain and thereby lose the ability to gain speed by pedaling because the chain tensioner unexpectedly moved to a position where it stopped acting as a tensioner. But, as a result, these chain tensioners can be difficult to work with, and cumbersome to remove because they are always fighting against being moved with their tension.
Chains and cassettes are typically changed rarely on road bikes. So, it is more imperative to ensure continuous chain tension than it is to enable easy removal of a cassette or wheel, or the crank of a bicycle meant for the roadway.
In contrast, a bicycle or bicycle frame mounted on a trainer, and intended for indoor use would benefit from a chain tensioner able to easily take up slack on a chain (particularly when used with a single-sprocket system envisioned by the inventor of this patent, discussed below) while also enabling the bicycle or bicycle frame to be added to or removed from the trainer. Therefore, it would be beneficial to have a chain tensioner that retains its position providing chain tension, but also enables easy removal of that tension and remains fixed without tension to provide a user the opportunity to mount or un-mount a bicycle or bicycle frame to a bicycle trainer. Although particularly useful in the case of a single sprocket system, such a tensioner is also useful in the case of a traditional cassette-based system.
U.S. patent application Ser. No. 18/084,809 filed Dec. 20, 2022, by the assignee of the present patent and the entirety of which is incorporated herein by reference, discloses one such single sprocket system. Another application disclosing a similar, adjustable single sprocket system, also incorporated by reference, was filed under U.S. patent application Ser. No. 18/976,899 on Dec. 11, 2024. One of the primary benefits of a single sprocket is ease of use from the perspective of a consumer. Unlike a typical cassette, the user need only wind the chain around a single gear (e.g. single sprocket). The user need not engage with or use a derailleur system and the user need not select a particular or preferred cassette with the associated selection of a number of gears for use with the cassette. The single sprocket—mounted to the bicycle trainer—may operate to simulate “virtual gears” using software controlling the associated trainer.
U.S. patent application Ser. No. 18/976,899 filed Dec. 11, 2024, by the assignee of the present patent and the entirety of which is incorporated herein by reference discloses a variation on the application umber Ser. No. 18/084,809 above which provides for an adjustable single-sprocket system in which tiny adjustments may be made to the single sprocket when not in use to enable it to move freely without chain interference or needless noise. This system may likewise be used with the chain tensioner disclosed herein.
Throughout this description, elements appearing in figures are assigned three-digit reference designators, where the most significant digit is the figure number and the two least significant digits are specific to the element. An element that is not described in conjunction with a figure may be presumed to have the same characteristics and function as a previously-described element having a reference designator with the same least significant digits.
The chain tensioner pulley 104 takes up the slack in the bicycle chain 102 or belt that would otherwise be present. The slack is needed for installation of the chain 102 around the crank 112 (gearing not shown) and any gears (or a single gear) 114. But, once the chain 102 is engaged with the crank 112 and gears, the slack is no longer needed, and the chain tensioner pulley 104 should be put in place to take up that slack. The position of the crank 112 is shown above on the right side) while the position of the gear(s) 114 is shown on the left side. Without the tensioner 104, the chain 102 would be slack and would not adequately engage the gears of crank 112 or the gear(s) 114 or both and the cycling experience or trainer-based exercise experience would be poor.
Also present in this system are the tensioner arm 106 and a pulley arm 108 which act as a mount and actuator for the tension provided by the overall chain tensioner system 100. The indoor cycle 110 frame is visible as a mount point for the crank 112.
The various states of the chain tensioner system 100 may be seen in
The tensioner element (e.g. the spring 107) is mounted to a point just at or near the pulley 104 itself on the pulley arm 106 (e.g., in the vicinity of the point where the pulley 104 is mounted on the pulley arm 106) and to a point on the bicycle frame (See
The same pulley arm 106, tensioner arm 108, indoor cycle 110, and crank 112 are also present.
The tensioner arm 108 is shown mounted within or on the frame of the indoor cycle 110. The tensioner arm 108 or the mount point or both may be an integral part of a bicycle frame or a trainer frame or may be mounted thereto by a bolt or rivet. Or, a portion of the bicycle frame may be modified to accept connection to or engagement with the spring 107 or the tensioner arm 108 or both.
The inventors herein have determined that, with the proposed configuration of this example, a tensioner element having 15 newtons of initial tension force when in either the closed or open position will have approximately 61.4 newtons of force in the working position (position [2] above). The resulting load being applied to the chain engaged with the pulley when in the closed position is approximately 1.25 kilograms. Likewise, the force FY (see
These proposed numbers are merely the case with the design proposed and may be any suitable numbers so long as the spring load in the over center position exceeds the load applied by the open or closed position pulley arm/spring combination. The exact numbers may vary dependent upon the configuration of the elements, lengths of the pulley arm, the tensioner arm, and the spring. The user experience is better if the load allows the system to maintain the engagement in the closed position while still allowing the user to relatively easily move the chain tensioner system between the open and closed positions. Otherwise, some sufficient strength may be required to engage and disengage the chain tensioner, making it inaccessible to individuals with insufficient strength to open the chain tensioner system. Likewise, too much force on the chain will inadvertently increase friction and resistance on the chain's movement. It is preferable that tension should be sufficiently maintained, but only lightly.
Alternative embodiments of the various components, arm lengths, spring strength, and the like are possible as well. For example, another suitable set of measurements are presented in the chart below.
Turning now to
This configuration is simpler to install by having a single mount point and a single pivot point 109, but overall has the same function as the design described above with reference to
Appendix A, incorporated herein by reference in its entirety, includes still more information regarding the specifics of the chain tensioner and its operation.
Clause 1. A chain tensioner system comprising:
Clause 2. A chain tensioner system comprising:
Clause 2. The chain tensioner system of any preceding clause further comprising a bicycle frame to which the fixed tensioner arm is mounted, wherein the bicycle frame is optionally combined with handlebars, a saddle, a crank, and pedals to form a bicycle.
Clause 4. The chain tensioner system of any preceding clause further comprising an indoor bicycle designed for exercise use indoors.
Clause 5. The chain tensioner system of any preceding clause wherein the tensioner element is a spring.
Clause 6. The chain tensioner system of any preceding clause wherein:
The pulley arm mount point of Clause 6 may for example be the pivot point of Clause 2. The tensioner mount point of Clause 6 may be one of the first and second connecting point of Clause 2 and the pulley arm mount point may be the other of the first and second connecting point of Clause 2.
Clause 7. The chain tensioner system of clause 6 wherein the tensioner arm is made up of two sub-arms, the sub-arms forming a semi-rectangle to which the tensioner element is mounted at the tensioner mount point behind the pulley arm pivot point as the tensioner element is stretched and the pulley arm is moved from the closed position to the open position.
Clause 8. The chain tensioner of any preceding clause wherein when the pulley arm is in the closed position, the pulley is positioned to engage with the bicycle chain or belt to provide tension in the bicycle chain and belt so as to maintain the bicycle chain or belt in engagement with a crank and a gear.
Clause 9. The chain tensioner of any preceding clause wherein when the pulley arm is in the open position, the pulley releases engagement with the bicycle chain or belt to release tension in the bicycle chain and belt so as to end the bicycle chain or belt engagement with a crank and a gear.
Clause 10. A chain tensioner system comprising:
Clause 11. The chain tensioner system of clause 10 wherein the tensioner element is a spring.
Clause 12. The chain tensioner system of clause 10 or 11 further comprising a bicycle frame to which the pulley arm is fixed at the pulley arm pivot point.
Clause 13. The chain tensioner system of clause 12 wherein the tensioner element fixed point is on or within the bicycle frame at a point furthest from the pulley arm end in the direction beyond the pulley arm pivot point.
Clause 14. The chain tensioner system of any one of clauses 10 to 13 further comprising a bicycle including a bicycle frame, a saddle, handlebars, the bicycle chain or belt, a crank, and pedals, wherein the pulley arm is fixed to the bicycle frame.
Clause 15. The chain tensioner system of any one of clauses 10 to 14 wherein when the pulley arm is in the closed position, the pulley engages with the bicycle chain or belt to provide tension in the bicycle chain and belt so as to maintain the bicycle chain or belt in engagement with the crank and a gear.
Clause 16. The chain tensioner system of any one of clauses 10 to 15 wherein when the pulley arm is in the open position, the pulley releases engagement with the bicycle chain or belt to release tension in the bicycle chain and belt so as to end the bicycle chain or belt engagement with the crank and a gear.
Clause 17. A bicycle system comprising:
Clause 18. The bicycle system of clause 17 wherein the tensioner element is a spring.
Clause 19. The bicycle system of clause 17 or 18 wherein the tensioner element fixed point is on or within the bicycle frame at a point furthest from the pulley arm end in the direction beyond the pulley arm pivot point.
Clause 20. The bicycle system of any one of clauses 17 to 19 further comprising a saddle, handlebars, the bicycle chain or belt, the crank, and the pedals, wherein the pulley arm is fixed to the bicycle frame.
Clause 21. The bicycle system of any one of clauses 17 to 20 wherein when the pulley arm is in the closed position, the pulley engages with the bicycle chain or belt to provide tension in the bicycle chain and belt so as to maintain the bicycle chain or belt in engagement with the crank and a gear.
Clause 22. The bicycle system of any one of clauses 17 to 21 wherein when the pulley arm is in the open position, the pulley releases engagement with the bicycle chain or belt to release tension in the bicycle chain and belt so as to end the bicycle chain or belt engagement with the crank and a gear.
Clause 23. An exercise system comprising
Throughout this description, the embodiments and examples shown should be considered as exemplars, rather than limitations on the apparatus and procedures disclosed or claimed. Although many of the examples presented herein involve specific combinations of method acts or system elements, it should be understood that those acts and those elements may be combined in other ways to accomplish the same objectives. With regard to flowcharts, additional and fewer steps may be taken, and the steps as shown may be combined or further refined to achieve the methods described herein. Acts, elements and features discussed only in connection with one embodiment are not intended to be excluded from a similar role in other embodiments.
As used herein, “plurality” means two or more. As used herein, a “set” of items may include one or more of such items. As used herein, whether in the written description or the claims, the terms “comprising”, “including”, “carrying”, “having”, “containing”, “involving”, and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of” and “consisting essentially of”, respectively, are closed or semi-closed transitional phrases with respect to claims. Use of ordinal terms such as “first”, “second”, “third”, etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements. As used herein, “and/or” means that the listed items are alternatives, but the alternatives also include any combination of the listed items.
Number | Date | Country | Kind |
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25153511.8 | Jan 2025 | EP | regional |
Number | Date | Country | |
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63624021 | Jan 2024 | US |