TECHNICAL FIELD

The present disclosure relates to a drivetrain guard, and in particular to a drivetrain guard for use on different chain, belt or string-driven machines, e.g. bicycles or

tricycles .

BACKGROUND

Drivetrain guards such as chain guards and drive belt guards are well known for protecting the (moving) chain or belt and drive wheels, respectively, and the environment from each other. Typical examples are chain guards for bicycles. Such chain guards are manufactured to fit the respective bicycle and do not, or at least not properly, fit other dimensions and/or geometries of the frame and/or of the drive train. Different dimensions and/or geometries of (parts of) the drivetrain may also be due to different diameters of one or both drive wheels and/or different distances between the drive wheels, which may occur when changing a configuration on the chain or belt driven machines .

It is noted that bicycle chain guards that are

adjustable in one form or another are known in the art. E.g.: DE 10 2007 028 271 discloses a flexible chain guard. The guard has a drive pinion gear, where a chain partially entangles the drive pinion gear. A movement zone is provided in a transition area in lump protection and a pinion gear protection. Resilience of the movement zone against the movement of the chain transverse to a chain direction is larger than the resilience of the lump protection and the pinion gear protection. The lump protection and the pinion protection are connected with one another in the movement zone in an articulated manner. EP 1 623 916 discloses a protective cover to shield a bicycle drive chain. The protective cover is provided with an opening) along its inner curve, for receiving the drive

sprocket, so that the part of the drive chain to be protected is covered by the protective cover. The cross-section of the protective cover is dimensioned so that it is held and centered on the drive chain.

DE 20 2014 005 667 discloses a chain guard for a bicycle, comprising at least one click connection element for attaching the chain guard to a bicycle, characterized in that the chain guard is provided with attachment means to fasten each click connection element arbitrarily to one of at least two different fastening points on the chain guard.

US 596,616 discloses a gear-case comprising a pair of spaced circular hoods adapted to respectively incase therein the front and rear sprockets of a bicycle, and each provided with a pair of tangential tubular extensions having a telescopic engagement with the similar extensions of the other hood to provide upper and lower casings for the sprocket-chain, each of said hoods being further provided with an inner flange disposed inside of and parallel with the outer rim, a detachable cover for each hood having a rim registering in the pocket formed between the flange and rim of the hood and also having a

tangential flanged extension adapted to embrace one of the tubular extensions of the hood, and bolts detachably clamping each cover in place.

US 610,313 discloses a chain guard. In the chain guard, a front casing is adapted to inclose the front gear and

comprising an inner section having an annular flange and two necks opening therethrough, and an outer section comprising a plate to close the outer side of the inner section, and provided with an annular flange to fit within the inner section and cut away at points opposite the necks. The outer section will be held securely to the inner section by friction, the cut-away portions of the flange permitting of the extension of the chain inclosing tubes within the casing.

However, further improvements in drivetrain guards are desired .

SUMMARY

In view of the above a drivetrain guard as specified herein is provided.

In an aspect, the drivetrain guard is for covering at least part of a drive wheel and an endless drive member operably supported on the drive wheel. The drivetrain guard comprises a drive wheel guard for at least partly housing and covering the drive wheel. The drivetrain guard further comprises at least two drive member guard sections for each at least partly housing and covering a running section of the endless drive member along a respective direction of extension of the respective running section. The drive wheel guard comprises at least two shells connectable or connected to each other, and the drive member guard sections are operably connectable or connected to the drive wheel guard. In a connected state of the shells and the drive member guard sections, the shells are rotatable with respect to each other between at least two configurations differing with respect to at least one of a mutual separation of the drive member guard sections and a mutual angle between the directions of extension of the drive member guard sections.

Thus, the provided drivetrain guard is adaptable to different drivetrain geometries. The direction of extension of the endless drive member guard may correspond to the directions of extension of the respective running sections of the drive member; here, "running section" means a section of the drive member not in contact with a drive wheel, typically a drive member section extending substantially straight between drive wheels (possible sagging of the running section being dependent on local drive member tension and direction of extension between adjacent drive wheels) .

Note that endless drive members running off and/or onto a drive wheel follow a path substantially tangential to the drive wheel circumference with which the drive member operably interacts; the circumference generally being circular with or without engagement portions, e.g. teeth, superimposed on the circumferential shape for with corresponding engagement portions of the endless drive member. The provided drivetrain guard enables adaptation to such tangential direction. E.g. the drivetrain guard is adaptable to drivetrain geometries differing with respect to sizes of drive wheels, and/or differing with respect to separation of drive wheels such that an angle defined by adjacent respective running sections of the drive member under consideration differs. In particular, the drive wheel guard is configured to closely conform and follow a drive wheel circumference and a tangential direction thereof and/or the shape of the associated drive member.

The drive member guard sections may be part of or separate from drive member guards. The drive member guards may be separate drive member guards facilitating providing a space between the drive member guards which could correspond to a space between running sections of the endless drive member for other purposes. This may reduce bulk of the drivetrain guard and it allows use of the space between the separate drive member guards for other purposes.

The rotation of the shells may preferably be about an axis, in use, coinciding with or at least parallel with an axis of rotation of the drive wheel to be covered. Thus, the

directions of extension of the drive member guard sections may be or correspond to tangential directions of the drive wheel to be covered.

The drivetrain guard may be configured to cover at least part of two drive wheels and an endless drive member operably supported on the drive wheels; wherein the drive wheel guard may be a first drive wheel guard and the drivetrain guard comprises at least a second drive wheel guard, the first and second drive wheel guards being for each at least partly housing and covering a respective one of the drive wheels, and at least one of the drive member guards extending between and connecting the first and second drive wheel guards.

Such drivetrain guard is particularly suitable for most common drivetrain geometries of two drive wheels opposite each other and connected by the drive member. In particular one of the drive wheels may have a relatively large diameter and the other drive wheel may have a relatively small diameter, so that a gear ratio other than 1:1 is provided for parallel axes. A typical example is a drivetrain for a transport apparatus such as a bicycle or a motorbike. However, both drive wheels may have equal sizes.

At least one of the shells may comprise an opening for accommodating an axle associated with the drive wheel to be covered. Optionally at least one of the shells comprises at least one side wall having a circumference, and a

circumferential wall section, and the opening extends from a circumference to a central portion of the side wall for mounting the shell sideways onto the axle, e.g. by sliding.

Thus, an axle onto which the drive wheel is mounted can enter the drivetrain guard so that only the drive train itself need be enclosed.

In a particular case, at least one of the shells comprises at least one side wall having a circumference, and a circumferential wall section, and the opening extends from a circumference to a central portion of the side wall for mounting the shell onto the axle, e.g. by sliding the shell onto the axis parallel to the drive wheel and in radial direction relative to the axis. This facilitates mounting the shell, and thus the entire drivetrain guard, onto (an object comprising) the drivetrain without dismantling the drivetrain.

Note further that the shell may be sized such that it can be mounted, e.g. by sliding, onto the drivetrain with the drive member operably mounted onto the drive wheel or -wheels unaltered. This may be particularly useful for an unbreakable drive member such as a belt or a string.

The drive train guard may further comprise one or more covers connectable or connected to the drive wheel guard and arranged to close an opening in a side wall and/or in a

circumferential wall section of a drive wheel guard.

This facilitates provision of a closed, possibly substantially fully closed drivetrain guard. A closed drivetrain guard protects (moving portions of) the drivetrain and an outside environment / persons from each other.

Each cover may comprise at least two connectable or connected shells that, in a connected state, are rotatable with respect to each other to vary a size and/or shape of the cover in accordance with a size and/or shape of the opening.

This facilitates adaptation of the drivetrain guard, as set out above, when assembled and closed.

Optionally, the cover is complementary to the drive wheel guard and/or the drive member guard section for providing a closed guard. This may further facilitate assembly of the drivetrain guard and/or improve that the drivetrain guard is closed .

At least one of the shells and/or a cover, if applicable, may comprise a drive member guard connector for fixing a drive member guard to a shell of the drive wheel guard such that the drive member guard rotates with said shell.

This facilitates adaptation of the drivetrain guard, as set put above, when assembled and closed. Further, this

facilitates aligning the drive member guard sections and

connected drive member guards to running sections of the drive member. The connector on the shell may be adjusted to be in line with the drive member, and in turn allowing the one or more drive member guards, when connected, to run tangentially to the drive wheels and parallel to the drive member. The connector may be arranged to at least partly cover the endless drive member running off and/or onto the drive wheel.

At least one of the shells of the drive wheel guard may comprise a locating element, preferably reversibly detachable, arranged to operably hold the shell generally concentrically to the centre of the drive wheel when said drive wheel cover is arranged for at least partly covering and housing said drive wheel .

Thus, the drivetrain guard may be located reliably about the axle of the drive wheel. This may facilitate aligning the directions of extension of the drive member guards to directions of extension of running sections of the drive member.

At least one of the drive member guards and/or drive member guard sections comprises at least two open channel sections connectable together to form a closed channel around a drive member section.

This facilitates mounting the drive member guard or drive member guard section (s) to the drive member when in place and/or mounting the drive member guard sections to an

unbreakable drive member such as a belt or a string; note that a bicycle chain may generally be opened and closed without loss in strength and/or function.

The guard may be fully closed or comprise openings wherein the largest open size is less than 5 mm, in particular when mounted onto one or more axles of respective drive wheels to be covered, in addition, any other opening may be effectively closed by a corresponding part, e.g. a connection to a pedal or to a drive engine operably connected with a drive wheel. Thus, the drivetrain guard, in particular when operably installed on an apparatus comprising a drivetrain covered by the drivetrain guard, may be considered safe according to the European Standard NEN EN 71. Also, the drivetrain guard itself and/or in operable combination with one or more parts of the drivetrain to be covered may adhere to any and all requirement of that Standard NEN EN 71.

The drivetrain guard may be supported by the drive wheel and/or on the drive member. However, since this may cause friction and/or wear of at least one of the drivetrain guard, the drive wheel and the drive member, the drivetrain guard may comprise a connector for attachment of the drivetrain guard to an apparatus comprising the drivetrain, e.g. a frame.

Preferably, the drivetrain guard comprises a connector for attachment of the drivetrain guard to at least part of the drivetrain itself, in particular a rotary connector which may take the form of a bearing, e.g. an axle connector. The bearing may be of a different material than the shells and/or the drive member guard sections and/or the drive member guards.

The drivetrain guard may be self-supporting. In particular, the drivetrain guard may be mountable or mounted self-supporting on at least part of the drive train, e.g. on one or more axles of (one or more drive wheels of) the drivetrain. E.g., the drivetrain guard may be mountable or mounted self- supporting on a connector as mentioned above. Here, "self- supporting" is intended to indicate that the drivetrain guard can maintain its shape, position and orientation without

requiring additional structures and/or connections to a frame of an apparatus from which the drivetrain guard is suspended and/or against which it is propped.

In the connected state of the shells and the drive member guard sections, the shells may be rotatable with respect to each other about an axis of rotation and the drive wheel guard may be operably mountable about the drive wheel to be covered, such that the axis of rotation of the shells

substantially coincides with an operable axis of rotation of the drive wheel and/or of the axle. E.g., at least one of the shells may comprise an opening for accommodating an axle associated with the drive wheel. This may ensure that the drive member guard sections maintain a constant direction relative to the drive wheel relative to the particular drive wheel under

relative rotation of the shells. The constant direction of the drive member guard section may be or approximate a tangential direction relative to the drive wheel.

An aspect of this disclosure is an assembly of an apparatus comprising a drivetrain which comprises at least one drive wheel and an endless drive member operably supported on the drive wheel, further comprising a suitable variant of the drivetrain guard disclosed herein. The drivetrain guard can accommodate adaptation of the geometry of the drivetrain.

The drivetrain may comprise two or more drive wheels. The drivetrain may be adjustable with respect to the sizes of the drive wheels and/or a separation of two drive wheels. The drivetrain guard can accommodate such adaptation of the geometry of the drivetrain.

The drive member may be a belt, a string, a chain or any combination.

The apparatus may be a transport apparatus, in

particular a muscle-driven transport apparatus, e.g. a bicycle, a tricycle, a quad or the like. The apparatus may be muscle- driven and/or engine driven.

The apparatus may be a modular apparatus, constructed of building modules. This may facilitate adaptation of the apparatus size and/or shape leading to adaptation of the

geometry of the drivetrain.

The apparatus, or rather the assembly, may be constructed from a kit of parts comprising a number of rods, a number of bends and/or hinges, a number of wheels, a number of connectors for connecting the rods, hinges and wheels together to form the transport apparatus. The kit further comprises a number of drive wheels and an endless drive member for forming a drivetrain for driving the transport apparatus, and a drivetrain guard as disclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-described aspects will hereafter be more explained with further details and benefits with reference to the drawings showing a number of embodiments by way of example.

Fig. 1 is a perspective view of a drivetrain guard, covering a drivetrain;

Fig. 2A and 2B are a partial cross section view and, respectively, a partial exploded view of the drivetrain guard covering the drivetrain, the drivetrain comprising a drive belt as an endless drive member;

Fig. 3 is an exploded view of the drivetrain guard of Figs. 1A-2B, without the drive member;

Fig. 4-6 are exploded views of (parts of) a drive wheel guard indicating assembly thereof;

Figs. 7-8 show the drive wheel guard in two different configurations ;

Figs. 9A-9D show different drive wheel guard geometries .

DETAILED DESCRIPTION OF EMBODIMENTS

It is noted that the drawings are schematic, not necessarily to scale and that details that are not required for understanding the present invention may have been omitted. The terms "upward", "downward", "below", "above", and the like relate to the embodiments as oriented in the drawings, unless otherwise specified. Further, elements that are at least

substantially identical or that perform an at least

substantially identical function are denoted by the same

numeral, where helpful individualised with alphabetic suffixes. Further, unless otherwise specified, terms like

"detachable" and "removably connected" are intended to mean that respective parts may be disconnected essentially without damage or destruction of either part, e.g. excluding structures in which the parts are integral (e.g. welded or moulded as one piece) , but including structures in which parts are attached by or as mated connectors, fasteners, releasable self-fastening features, etc.

Fig. 1 shows a drivetrain guard 1 as provided herein. Fig. 2A also shows the drivetrain guard 1, partly cut away as indicated by the cutting plane II indicated in Fig. 1; Fig. 2B is a partial exploded view of the drivetrain guard 1. The shown guard 1 may fit a traditional bicycle drivetrain with a

relatively large front drive wheel 2A (typically a pedal sprocket as a driving wheel) and a relatively small rear drive wheel 2B (typically an axle sprocket as a driven wheel) operably supporting an endless drive member 3 such as a belt. The drive wheels 2A, 2B are each operably mounted on an axle 4A, 4B, respectively. However, the present disclosure is in no way limited to such design and/or use. E.g. the drivetrain could be of or for another apparatus, which could be a stationary

machine; the endless drive member could be a string or a

combination of chain, belt and/or string; the drive wheels could be toothed or not; also, the drive train could comprise more drive wheels and/or drive member guides.

The drivetrain guard 1, configured for covering at least part of the drive wheels 2A, 2B of mutually different sizes and the endless drive member 3 operably supported on the drive wheels 2A, 2B. The drivetrain guard 1 comprises a first drive wheel guard 5 and a second drive wheel guard 7 for each at least partly housing and covering a respective drive wheel 2A, 2B. The drivetrain guard 1 further comprises drive member guards 9, 11 for each at least partly housing and covering a running section 15, 17 of the endless drive member 3 along a respective direction of extension E15, E17 of the respective unsupported section 15, 17.

The first and second drive wheel guards 5, 7 are of the same construction, but differing by size. The following

discussion relating to the first drive wheel guard 5 therefore equally applies to the second drive guard 7.

The drive wheel guard 5 comprises an outer guard 18 which comprises shells 19 that are connectable (Fig. 4) to each other to form, when connected (e.g. Figs. 5, 6), a portion of the drive wheel guard 5. The drive member guards 9, 11 are operably connectable to the drive wheel guard 5.

The (shells 19 of the) outer guard 18 each comprise an opening 21 for accommodating the axle 4A associated with the drive wheel 2A to be covered. In the shown embodiment, the shells 19 comprise a side wall 23 having a circumference 25 and a circumferential wall section 26, and the opening 21 extends from the circumference 25 to a central portion of the side wall 23 for mounting the shell 19 sideways onto the axle, e.g. by sliding. Thus, the shell 19 can be mounted to the axle 4A

parallel to the drive wheel 2A and perpendicular to the axle 4A. Note that such mounting can be done also when the drive wheel 2A (or even the entire drive train) is mounted to a frame of an apparatus (not shown) ; wherein the shell 19 may fit between the drive wheel 2A and the frame.

One or more covers such as inner guard 27 are connectable or connected to the shells 19 and arranged to close the opening 21 in the side wall 23 and/or in the circumferential wall section 26 of the drive wheel guard 5. Further covers arranged to close further openings may be provided as well, see below .

The inner guard 27 comprises at least two connectable (Fig. 5) shells 29 that, in a connected state (Fig. 6), are rotatable with respect to each other to vary a size and/or shape of the guard 27 in accordance with a size and/or shape of the opening 21 in the shells 19 of the drive wheel guard 5. In particular, the size and shape of fins 28 of the inner guard 27 are complementary to the size and shape of the opening 21 in the shells 19 of the drive wheel guard 5. Thus, when inserted into the shells 19, a closed drive member guard 5 is provided (Fig.

7) .

The shells 19 and respectively 29 of the drive wheel guard 5 may be, as here, mutually identical, e.g. being moulded in the same mould.

Best seen in Fig. 3, each drive member guard 9, 11 comprises at least two open channel sections 30, 31 connectable together to form a closed channel around a running drive member section 15, 17 (e.g. see Fig. 2) .

The shells 19 comprise a drive member guard section 33 formed as a connector for fixing a drive member guard 9, 11 to a shell 19 of the drive wheel guard 5. Here, the fixation is by sliding and/or snapping channel sections 30 of the drive member guard 9, 11 onto the connector 33. The fixation may be, as here, releasable. When thus connected, the drive member guard section

33 and thus the drive member guard 9 or 11 can rotate with the respective shell 19, see below.

The shells 29 of the inner guard 27 comprise side walls

34 and a complementary connector 35 with which each shell 29 is releasably connectable to a respective drive member guard connector 33. Further fixation measures of the inner guard 27 to the shells 19, e.g. latches, bolts, screws, additional

connectors, etc. may be provided but are not needed in the shown embodiment. The connector 35 further closes off the drive member guard connector 33 towards the inside (i.e. a side of the drive train where the drive member is unsupported by a drive wheel) the drive member guard connector 33 here being formed as an open channel . For connecting the shells 19 of the outer guard 18 together, the shells comprise mated connection portions. In the shown embodiment, each shell 19 comprises a cup 37 into which a corresponding portion of the other shell 19 fits (generally indicated with 39 in Fig. 4) . A protrusion 41 and a mated recess 43 (here, the recess is open to an outside and forms a curved slot) interlock the shells 19 and secure the connection (Figs. 4-5) .

Best seen from Figs. 7 and 8, in a connected state the shells 19 and 29 are rotatable with respect to each other about a common axis A substantially perpendicular to a plane in which the drive wheel guard 5 and drive member guards 9, 11 extend, corresponding to a plane of the drivetrain. Thus, the shells 19 are rotatable with respect to each other between at least two configurations (compare Figs. 7, 8) differing with respect to at least one of a mutual separation S of the drive member guard sections 33 and therewith of the drive member guards 9, 11 and a mutual angle ex between the directions of extension of the drive member guard sections 9, 11. Portions of the sidewalls 26 of the shells 19 and, respectively, the side walls 34 of the shells 29, slide along and over each other during such rotation so that the drive wheel guard 5 remains closed in both configurations. More than two configurations may be possible and adjustment between different configurations may be continuous or stepwise, e.g. via ratchets in or on the shells and/or via width variations of the recess 43 engaging the protrusion 41. The angle of rotation a may be limited by interaction of parts of the shells 19, e.g. protrusion 41 and recess 43; the curvature of the recess 43 facilitates the rotation.

Each shell 19 is further provided with a locating element, here being in the form of a clamp 45, reversibly detachably arranged to operably hold the shell 19 generally concentrically to the axle 4A operably (concentric) attached to the drive wheel 2A to be housed and covered by the drive wheel guard 18. The locating element may fit the optional adapter 24 (cf. Figs. 1 and 2B) . However, optionally locating element like clamps could be also and/or alternatively be connected or connectable to the inner guard 27 and/or be at least partially integrated in (shells 19, 29 of) the inner and/or outer guard 18, 27. The clamp connection may be snapping.

When connected to the axle 4A, the axis of rotation A of (the shells 19, 29) of the drive wheel guard 5 substantially coincides with an operable axis of rotation of the axle 4A and thus of the covered drive wheel 2A. By providing the connectors 45 as separate members, the connectors may be provided of suitable materials and/or be readily replaceable; the same holds for the adapter 24. This may be particularly useful in case of mounting to an axle in view of wear against a moving element.

In case the axle is not circular about the axis of rotation (e.g. the shown axles 4A, 4B being hexagonal in cross section) , an axle connector 47 may be proved to the axle

providing a circular circumference about the axis of rotation of the axle (Fig. 2B) . Thus, the locating element 45 may be part of a connector mated to the axle connector 47, together forming a bearing. The bearing may be of a different material than the shells and/or the drive member guards. E.g. the clamp 45 and/or the axle connector 47 may be at least in part of Nylon or

Teflon, because of their elastic and/or low-friction properties whereas the shells may be of a ABS, ASA polyvinyl, HDPE, polypropylene, PET and/or an (meth- ) acrylate material, because of their manufacturability and robustness properties.

Also, when thus connected to an axle, all openings of the drivetrain guard 1 may be closed and/or covered to provide a largest open size of less than 5 mm or 4,6 mm (0,2 inch) so that moving elements inside and users outside the drivetrain guard 1 are protected from each other.

Figs. 9A-9D show different drive wheel guard geometries. Figs. 9A-9B show that one set of drive wheel guards as discussed herein with a given diameter size f _$ , fh , and drive member guards of different lengths LA, LB, drivetrain guards of different geometries (in particular: different angles a _A , <¾) may be constructed for drivetrains with different drive member lengths. Since drive member guards may be manufactured at relatively low cost, the drivetrain guard can be (made to) fit to different drivetrain geometries cost-effectively. Also, two same-size drive wheel guards, here having diameters f _c , fh, respectively, may be combined to a drivetrain guard with

parallel drive member guards of equal lengths L _c , L _D , spaced by separations S _c , S _D , respectively (Figs. 9C-9D) .

The disclosure is not restricted to the above described embodiments which can be varied in a number of ways within the scope of the claims. For instance, different sizes and shapes may be provided. Further, it should be noted that in the

embodiments discussed above and shown in the Figures, all shells and drive member guard channels are open so that they can be fit to an existing drivetrain mounted onto a frame without

disassembly of that drivetrain.

Further, the drivetrain guard can be fit to a drivetrain comprising an "unbreakable" drive member. As an alternative, a drive member guard and/or a drive wheel guard may be formed with an enclosed section (e.g. an inner guard

connector 35 being ring-shaped instead of comprising clamping arms as shown) so that the drive member must be opened and fed through the enclosed section. This is feasible for openable and reclosable dive members like common bicycle chains and/or drive members comprising a connector. Such alternative drivetrain guard may provide further increased strength and/or robustness.

The drive member guards may be modular along the length of the running drive member section; such modules may be

mutually interconnectable, e.g. by comprising a diameter

variation like a conical portions such that one such module may be inserted partially into an adjacent module telescopically. Elements and aspects discussed for or in relation with a particular embodiment may be suitably combined with elements and aspects of other embodiments, unless explicitly stated otherwise .