Sprocket carrier assembly

Abstract

A sprocket carrier assembly 10 for engaging with a go-kart sprocket (26; fig. 10-13). The assembly comprises: a sprocket carrier 12; a nut 20; and at least one locator lug 76 for aligning a sprocket with the sprocket carrier 12 and the nut 20. The sprocket carrier 12 comprises: an inner body portion 14 including an integrally formed first threaded connector 16 (easiest to see in fig. 3); and a radially outer body portion 18, at which the locator lug(s) 76 are located, e.g. selectively engageable via apertures 74. The lug(s) 76 are dimensioned to engage with apertures (96; fig. 10) on the sprocket. The nut 20 (easiest to see in fig. 7) comprises a second threaded connector 24, engageable with the first threaded connector 16 to hold a sprocket therebetween. The first and second threads may have a diameter wider than a central axle engagement bore 62. There may be secondary locking via a slot 44 in the first threaded connector and a locking fastener (e.g. nut, bolt, screw 46 re aperture 48; fig. 2) to tighten the slot. The assembly may also include wear shim 86 and sprocket protector (54; fig. 13).

Description

The present invention relates to a sprocket carrier assembly for holding a sprocket, particularly a sprocket as used on a kart. Kart racing or karting is a motorsport discipline using four-wheeled vehicles known as go-karts or shifter karts. It is often the first experience of motorsports available to young drivers, as karts can be driven from a younger age than traditional motor cars. All karts require gearing mechanisms to enhance a driver’s speed. There is a variety of engine types and chassis types that are used by kart racers, but the most common arrangement involves providing drive to the rear axle via a gearing mechanism using standard sprocket carriers, sprockets, and chains. With a traditional sprocket and carrier, a mechanic needs to remove the sprocket by undoing up to six nuts and bolts which can be awkward to access and time-consuming. The current standard sprocket carrier has gaps between the bolt holes which can result in warping of the sprocket which in turn could throw off the chain to the engine leaving the kart at a standstill. Furthermore, the arrangement of current sprocket carriers means that all securing friction and tension is directed towards the small surface area of the securing bolts, rather than across the whole sprocket. This promotes warping and gradual diminishment of the bolt holes of the sprocket, and ultimate wear to a point beyond useability, even if the outer sprocket spokes are still in a useable condition. Furthermore, any technologies that may reduce the time taken to change a sprocket in the art do not account for universality and can only be performed with proprietary sprockets and sprocket protector plates, severely reducing the flexibility to the user when at different event locations. It is an object of the present invention to reduce or substantially obviate the aforementioned problems. According to a first aspect of the invention, there is provided a sprocket carrier assembly for a kart, the sprocket carrier assembly comprising: a sprocket carrier having an inner body portion comprising an integrally formed first threaded connector and an outer body portion positioned radially outwardly of the inner body portion; at least one locator lug located on the outer body portion of the sprocket carrier, the or each locator lug being dimensioned to engage with an aperture of a sprocket to be carried; and a nut having a second threaded connector engageable with the first threaded connector to secure a sprocket to be carried in place. This is advantageous as it allows the user to change kart gears more rapidly than with sprocket carriers currently available in the art, particularly those that use several nut and bolt type fasteners to connect the sprocket to the carrier. The design allows the sprocket carrier to be connected at the centre with minimal difficulty and comprises fewer overall parts that can become lost or damaged during the procedure. The integral formation of the first threaded connector also provides reduction in device footprint and weight by preventing the need for multiple parts. Optionally, the sprocket carrier may have an axle engagement bore, the first and second threaded connectors having a diameter greater than that of the axle engagement bore. This is advantageous as it permits stable connection of the sprocket carrier to the axle of a vehicle such as a kart or other motorised vehicle that utilises sprocket mechanisms. The larger diameter of the threaded connectors allows for threaded engagement therebetween, so that engagement can be coaxial with the axle of the kart. Preferably, the first threaded connector may be a male threaded connector having an external thread and the second threaded connector is a female threaded connector having an internal thread. This is advantageous as it permits a rapid securing means without the need of additional parts or guides. The first and second threaded connectors can shape-matingly come together to form a strong, stable connection with minimal user input or exertion. Optionally, the at least one locator lug may be releasably engageable with the sprocket carrier. This is beneficial, as it allows lugs to be replaced when certain parts of the lug are worn from use. If the lugs were exclusively attached to the sprocket carrier assembly, then the whole unit would need replacing if any damage or wear occurred. As the lugs are used constantly as a way to guide the sprocket into the correct position, and remain attached whilst the sprocket is attached, they will suffer from frictional wear and other damage. Furthermore, it allows there to be an exchange of lugs for lugs of different sizes to fit different shapes and types of sprockets, increasing flexibility to the user. Preferably, the at least one locator lug may be threadingly engageable with a corresponding receiver of the outer body portion of the sprocket carrier. This is advantageous as it provides a simple and rapid secure means to fasten the locator lugs to the outer body portion of the sprocket carrier. This fit also prevents the locator lugs from accidental displacement during use. Optionally, a plurality of different locator lugs may be provided, the plurality of locator lugs being selectably engageable with the sprocket carrier depending on the sprocket to be carried. This is advantageous as a number of different sprockets may only be available at certain locations, rather than specific proprietary ones that only fit certain sprocket carriers. The different locator lugs of different sizes and selectable engageability allows a unique user-tailored experience for selecting universal sprockets depending on requirement. Preferably, the nut may have an ergonomic outer perimeter. This is beneficial as it provides the user with a comfortable and ergonomic shape to permit easy securing and release of the sprocket carrier assembly. The nut is shaped so as to allow the nut to be removed quickly and without undue force which increases longevity of the nut itself and does not burden the user with any potential injuries. Furthermore, the shape allows the nut to be initially adjusted by the user without any additional tools or components. Optionally, the sprocket carrier may be a split sprocket carrier. This is advantageous as it provides a way to remove the sprocket during vehicle arrangements where the sprocket carrier must be mounted between the axle bearings and is subsequently irremovable without disassembly of the axle from the vehicular body. The split sprocket carrier permits removal of the sprocket carrier and sprocket without necessitating the removal of the axle or any other parts, rapidly increasing the sprocket exchange process, even in situations where it would typically take substantially longer. Preferably, the sprocket carrier assembly may further comprise a secondary locking means for locking the nut to the sprocket carrier, wherein the secondary locking means is operable in a direction parallel to a direction of rotation of the sprocket carrier assembly in use and the secondary locking means comprises a slot in the first threaded connector and a locking fastener for tightening the slot. This is beneficial as it provides a way to secure the nut to the sprocket carrier in a way that prevents accidental disassembly. Movement of the sprocket carrier during operation may lead to gradual warping of the threaded connectors and / or eventual disassembly of the first and second threaded connectors causing the sprocket carrier to come apart. Furthermore, the secondary locking means allows consistent pressure to be applied around the sprocket, preventing any warping, or scuffing that may occur should the first securing means loosen in any capacity. Optionally, the sprocket carrier may be formed from a non-ferrous material. Advantageously, non-ferrous materials are impervious to rust and are typically more lightweight. This is beneficial in two ways, as it prevents the sprocket carrier assembly from requiring cleaning, replacement, or other maintenance as a result of typical oxidation. Furthermore, by using lightweight materials, the sprocket carrier assembly does not add additional weight burdens that may reduce speed, torque, or control of the vehicle when in use. Preferably, a centre of rotation of the nut may be coincident with a central axis of the sprocket carrier. This is beneficial, as it permits the nut to align with the sprocket carrier in a way that is not difficult to achieve and provides a tight connection across the whole diameter of the sprocket carrier. Having the alignment on the same axis also means that all apertures for any further securing means or protector plates are able to be aligned in a more straightforward fashion. Optionally, the nut may define a continuous annular contact surface for engagement with a sprocket, wear shim, or sprocket protector when carried by the sprocket carrier assembly. Advantageously, the continuous annular contact surface provided prevents substantial wear when the sprocket is in use and is in contact with the various metal surfaces. This prevents warping occurring at single stress points and distributes the forces across the whole sprocket object. Preferably, the sprocket carrier assembly may comprise a wear shim receivable between the sprocket carrier and the nut This is advantageous because the wear shim can be made of a more lightweight material that generates less friction upon contact with the sprocket when it is held between the sprocket carrier and the nut. This prevents wear to the sprocket and can increase sprocket longevity. Furthermore, inclusion of an additional wear shim that is cheaper to manufacture means that damage and frictional wear from the sprocket to the sprocket carrier and nut is redirected towards a part that can be replaced easily, rather than necessitating costly replacement of the sprocket carrier and / or nut. Optionally, the sprocket carrier assembly may comprise a sprocket protector. This is beneficial as it can prevent wear and damage occurring to the sprocket itself, but also the sprocket carrier, the nut, and any other associated parts with the sprocket carrier assembly. The sprocket protectors can protect from environmental damage, prevent small connection elements being lost and may improve the overall aesthetic for the user. Furthermore, sprocket protectors actively prevent the sprocket chain from becoming displaced from the sprocket during use. For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made by way of example only to the accompanying drawings, in which: Figure 1 shows an exploded view of a first embodiment of a sprocket carrier assembly, in accordance with the first aspect of the invention; Figure 2 shows a front view of the sprocket carrier assembly of Figure 1; Figure 3 shows a perspective view of the sprocket carrier of the sprocket carrier assembly of Figure 1; Figure 4 shows a front horizontal view of the sprocket carrier of Figure 3; Figure 5 shows a side vertical view of the sprocket carrier of Figure 3; Figure 6 shows an alternative side vertical view of the sprocket carrier of Figure 3; Figure 7 shows a perspective view of a first embodiment of a nut of the sprocket carrier assembly of Figure 1; Figure 8 shows a side view of the nut of Figure 7. Figure 9 shows a side view of a sprocket locator lug for use with the sprocket carrier assembly of Figure 1; Figure 10 shows a front perspective view of the sprocket carrier assembly of Figure 1 in an in-use arrangement with a sprocket; Figure 11 shows a back perspective view of the sprocket carrier assembly of Figure 10; Figure 12 shows a side view of the sprocket carrier assembly of Figure 10; Figure 13 shows a perspective view of the sprocket carrier assembly of Figures 10 to 12 further engaged with sprocket protector plates; Figure 14 shows a perspective view of a wear shim that is seated therebetween the sprocket carrier and the sprocket; and Figure 15 shows a side view of a second embodiment of the nut of a sprocket carrier assembly in accordance with the first aspect of the invention. Referring firstly to Figures 1 and 2, there is shown a sprocket carrier assembly referenced globally at 10 comprising a sprocket carrier 12 with an inner body portion 14 that has an integrally formed first threaded connector 16, and an outer body portion 18 and a nut 20. The nut 20 has a central aperture 22 for engaging with the sprocket carrier 12. The nut 20 specifically has an integrally formed second threaded connector 24 that is engageable with the first threaded connector 16 to secure a sprocket 26 therebetween. The nut 20 has a nut inner body 28 and a nut outer body 30. Both the outer body portion 18 of the sprocket carrier 12 and the nut outer body 30 of the nut 20 have a series of ergonomic recesses 32 that are ergonomically designed for user contact, that is, for ease of gripping by one hand. The nut inner body 28 has an inwardly-facing nut surface 34 and an outwardly-facing nut surface 36. The second threaded connector 24 is located on the inwardly-facing nut surface 34 of the nut inner body 28. The outwardly-facing nut surface 36 provides a clearance relative to the outer body portion 18 when in-use. This further provides a space for the sprocket 26 to be seated. The nut inner body 28 also has a nut clamping surface 38 which is formed as a surface of part of the nut inner body 28 and is positioned outwardly on a bottom surface of the nut inner body 28. The inner body portion 14 of the sprocket carrier 12 further comprises a carrier clamping support portion 40 which forms a base for inner body portion 14. Said carrier clamping support portion 40 is proud relative to the outer body portion 18. A space between the circumferential sides of the inner body portion 14 of the sprocket carrier 12 and the circumferential edges of the top edge of the carrier clamping support portion 40, relative to the outer body portion 18, forms a carrier clamping surface 42 thereon. The purpose of the comparatively small dimension of the carrier clamping surface 42 is to provide a clearance to prevent the sprocket from wearing against a large surface area. When the nut 20 and the sprocket carrier 12 are brought together either in-use with a sprocket 26 or without a sprocket, the carrier clamping surface 42 and the nut clamping surface 38 come together to form a clearance space to prevent sprocket wear. Both the first threaded connector 16 of the sprocket carrier 12 and the second threaded connector 24 of the nut 20 are positioned circumferentially on the inner body portion 14 and the nut inner body 28, respectively, and are releasably engageable across the whole of these circumferences. The primary locking means is provided by the releasable engagement of the first threaded connector 16 of the sprocket carrier 12 with the second threaded connector 24 of the nut 20. Shown in particular detail in Figures 1 to 4, a slot 44 is provided in the first threaded connector 16 of the inner body portion 14 of the sprocket carrier 12 which provides a secondary locking means. The secondary locking means is achieved through the action of a locking fastener 46 which may be a nut, bolt, screw, or another securing item. The locking fastener 46 is insertable into a securing aperture 48, of which is formed on one of the bridging members 50 and positioned so as to be engageable with the slot 44. The locking fastener 46 provides a way to tighten the complementary threaded connection between the first threaded connector 16 and the second threaded connector 24 when engaged and in-use. The secondary locking means is achieved in the exemplified embodiment by tightening and deformation of the metal slot 44 around the threaded connection imparted by the first threaded connector 16 and the second threaded connector 24. This deformation is induced by insertion of the locking fastener 46 into the securing aperture 48. The outer body portion 18 of the sprocket carrier 12 has a plurality of circumferentially spaced outer body apertures 52a, whilst the nut outer body 30 also provides a plurality of circumferentially spaced nut body apertures 52b. These apertures 52a, 52b are available to secure optional sprocket protector plates 54 on the external diameters provided by the outer body portion 18 and the nut outer body 30. Further shown, with particular reference to Figures 2 and 3, is the axle engagement sleeve 56 which has a head portion 58 and a neck portion 60. The axle engagement sleeve 56 is a circular aperture formed as a protruding hollow member upstanding from the centre of the sprocket carrier 12. The void space in the centre of the axle engagement sleeve 56 thereby forms the axle engagement bore 62. The axle engagement sleeve 56 is connected to the inner body portion 14 of the sprocket carrier 12 through a plurality of bridging members 50 that protrude outwardly from the outer surface 64 of the axle engagement sleeve 56 that forms the axle engagement bore 62. The inner surface 66 of the axle engagement sleeve 56 has an axle engagement groove keyway 68 for securing to a corresponding alignment member of a kart axle. The axle engagement sleeve 56 of the sprocket carrier 12 forms a split sprocket carrier. Splits 70a in the axle engagement sleeve 56 can be used to apply a clamping force onto the kart axle using one or more fasteners 70b, such as bolts. The bolts are placed in boltreceiver apertures 72. The outer body portion 18 of the sprocket carrier 12 has a plurality of locator lug apertures 74 for engaging with a locator lug 76. In the embodiment shown, the locator lugs 76 releasably engage with the locator lug apertures 74. The locator lugs 76 are formed as a single piece with three parts of different dimensions. The carrier-engaging portion 78, the flange portion 80 and the sprocket-engaging portion 82. These are arranged in a way that allows the carrier-engaging portion 78 to releasably engage with the lug apertures 74 of the outer body portion 18 of the sprocket carrier 12. It further allows the flange portion 80 to provide extra stability, and a means of supporting the sprocket-engaging portion 82 which engages with the sprocket 26 itself. Each locator lug 76 may have a thread, located on the outer surface of the carrierengaging portion 78 which may connect with a complementary thread present within the inner circumferential surface of the locator lug apertures 74 of the outer body portion 18. These fit together through a screw-fit mechanism. It may also be envisioned that a different type of connection mechanism is used, such as a push-fit, wedge-fit, or bolt-fit. In this particular embodiment, there are no threads on the locator lugs or the locator lug apertures, and it is simply a friction fit. The locator lug apertures 74 on the outer body portion 18 are larger in diameter than the apertures of an associated sprocket 26. Further, the flange portion 80 allows the locator lug 76 to sit flush relative to the surface of the outer body portion 18. With this design, the sprocket-engaging portion 82 is positioned so as to protrude outwardly and engage with a sprocket 26. The sprocket-engaging portion 82 is of a diameter suitable for engaging with a sprocket 26 and not the lug apertures 74 of the outer body portion 18. This allows the locator lugs 76 to only be inserted the correct way. The locator lug apertures 74 also have a fitting lip 84, to prevent the locator lug 76 from falling straight through and to provide extra stability, strength, and support. A wear shim 86 is shown between the sprocket carrier 12 and the nut 20 that has a series of shim apertures 88 that can engage with the sprocket-engaging portion 82 of the locator lugs 76 and has the same shape as the outer body portion 18 of the sprocket carrier 12. The shim apertures 88 are complementarily-dimensioned to the sprocketengaging portion 82 of the locator lugs 76 so that the locator lugs 76 are able to connect to a sprocket 26. The wear shim 86 may be formed of a polymer, plastic, or other resiliently flexible and wearable material. Specifically, the wear shim 86 is designed from a polymeric or plastic material as this is less rigid and hard, providing a surface with less tensile strength, providing an interactive surface that is less harsh and generates less friction against the sprocket 26 when moving in-use. The front of the sprocket carrier assembly 10 is shown in Figure 2, showing the different shapes of the outer body portion 18 of the sprocket carrier 12, and the nut outer body 30 of the nut 20. There is a greater number of apertures 52b on the nut outer body 30 than apertures 52a on the outer body portion 18. This is because when in-use, the sprocket carrier 12 is not the moveable part, but the nut remains the primary moveable element. As such, having a plurality of nut body apertures 52b on the nut outer body 30 means there is more likely to be a nut body aperture 52b available to align without undue force or loosening of the nut 20 with complementary holes in the sprocket 26. Referring to Figures 3 to 6, there is shown the sprocket carrier 12 of the sprocket carrier assembly 10 without the nut 20. Visible is the presence of the axle engagement groove keyway 68 formed as a channel extending from the edge of the circumference of the inner surface 66 of the axle engagement sleeve 56. Also shown are the splits 70a that form a partial slot between two opposing sides of the axle engagement sleeve 56, thereby forming two pseudo-semicircles of the circumference of the axle engagement sleeve 56. The splits 70a function as a securing means which are tightenable when the axle engagement bore 62 of the axle engagement sleeve 56 is positioned on an axle. The splits 70a are tightenable through a fastener 70b, accessible from the bolt-receiver apertures 72 as detailed in Figure 5. With particular reference to Figures 3, 5, and 6, the axle engagement sleeve 56 is shown as having a head portion 58 and a neck portion 60. The threaded base of the fastener 70b is also shown as pending from the bolt-receiver aperture 72 of Figure 6 which is the means in which the splits 70a are tightened to secure the axle engagement bore around an axle. The purpose of the neck portion is to reduce overall weight of the sprocket carrier assembly 10, whilst still maintaining sufficient clearance space to prevent sprocket wear. Referring to Figure 7 and 8, there is shown the nut 20 in one exemplary embodiment. Visible is the nut inner body 28 and the nut outer body 30 with the series of nut body apertures 52b. The side view of Figure 8 shows the nut inner body 28, of which the inner circumferential surface is the inwardly-facing nut surface 34 and comprises the second threaded connector 24 used to attach the nut 20 to the sprocket carrier 12. Visible in Figure 8 is the outwardly-facing nut surface 36 and the nut clamping surface 38 which is formed as part of the nut inner body 28. In reference to Figure 9, there is shown a locator lug 76 with the interior void space 90 marked by dashed lines. Further visible is the carrier-engaging portion 78, the sprocketengaging portion 82 with the flange portion 80 therebetween. The interior void space provides access to the carrier-engaging portion 78 as a means of tightening the threaded connection or any other form of securing means that may have been employed to tighten the locator lugs 76. The void space permits access to a tightening element of some form. In this particular embodiment, the locator lug may have a thread located on the outer surface of the carrier-engaging portion 78 which connects with a complementary thread present within the inner circumferential surface of the locator lug apertures 74. However, in this particular embodiment, no thread is used, but rather a friction fit. In reference to Figures 10 to 13, there is shown an in-use arrangement of the sprocket carrier assembly 10. The sprocket 26 is shown as having a plurality of radial spokes 92 facing outwardly and a plurality of outer sprocket apertures 94 and inner sprocket apertures 96. Specifically in this particular embodiment, the sprocket carrier 12 and nut 20 are shown with a sprocket 26 therebetween, the sprocket carrier 12 and the nut 20 are aligned to the sprocket through the inner sprocket apertures 96 engaging with locator lugs 76.The sprocket carrier assembly 10 in this arrangement is securing the sprocket 26 through the securing engagement of the first threaded connector 16 and the second threaded connector 24 of the sprocket carrier 12 and the nut 20, respectively. With specific reference to Figure 12, the outwardly-facing nut surface 36 is visible which provides a clearance space between the nut outer body 30 and the sprocket 26. In reference to Figure 13, there is shown the sprocket carrier assembly 10 engaged with a sprocket 26 and optional sprocket protector plates 54. The sprocket protector plates 54 can be affixed to the sprocket carrier assembly 10 via the complementary protector plate apertures 98 that are formed as part of the sprocket protector plates 54 that in-use align with the nut body apertures 52b in the nut outer body 30, and the outer body apertures 52a in the outer body portion 18 which may align with the outer sprocket apertures 94 or the inner sprocket apertures 96 depending on what exemplary sprocket 26 is provided. Referring to Figure 14, there is shown the wear shim 86 for reducing wear between the sprocket and the constituent parts of the sprocket carrier assembly 10. The wear shim 86 also has a series of shim apertures 88 to fit to the locator lugs 76 and align with the inner sprocket apertures 96, outer sprocket apertures 94 and both the nut body apertures 52b in the nut outer body 30 and the outer body apertures 52a in the outer body portion 18, so that the locator lugs 76 may also secure the wear shim 86 in the correct position and to keep it aligned with the other elements necessary for securing the sprocket 26 in place. The wear shim 86 is formed to be as lightweight as possible, by using a lightweight material for instance, or minimising the thickness thereof. The wear shim is shaped the same as the outer body portion 18 of the sprocket carrier 12 as this is the surface with which the sprocket 26 remains in direct contact. Referring to Figure 15, there is shown an alternative embodiment of the nut 20’ of the sprocket carrier assembly 10 when sprocket protector plates 54 are not required. There is still a nut inner body 28’ and a nut outer body 30’, however, the nut inner body 28’ is substantially reduced in diameter, providing a narrower outwardly-facing nut surface 36’, whilst still comprising the second threaded connector 24’ and a nut clamping surface 38’. However, a large outer diameter is not required in order to reduce excess weight. A wider outer circumference of the nut outer body 30’ is not necessary when sprocket protector plates 54 are not required. As such, this nut outer body 30’ width can be reduced into a streamline nut 20’. Although in the particular embodiments exemplified herein the locator lugs are stated as having threads at the carrier-engaging portion to provide a threaded connection between the locator lugs and the locator lug apertures. It may be envisaged that this is a push-fit connection, or some other form of wedging fit that interacts with a bolt or screw in the interior void space. It may also be that the locator lugs are not tightened or secured in any form and are simply used as locators rather than specific locator lugs. It may also be that the locator lugs are integrally formed as part of the outer body portion of the sprocket carrier or even as part of the nut outer body of the nut. Provided herein is a sprocket carrier assembly for carrying a sprocket. The sprocket carrier assembly comprises a sprocket carrier, locator lugs and a nut, the sprocket carrier and nut being releasably engageable to hold a sprocket therebetween, with the locator lugs being used to align the sprocket in the correct location. The sprocket carrier assembly also has an axle engagement sleeve for mounting to a vehicle axle, particularly a kart or other small recreational vehicle. The words ‘comprises / comprising’ and the words ‘having / including’ when used herein with reference to the present invention are used to specify the presence of stated features, integers, steps, or components, but do not preclude the presence or addition of one or more other features, integers, steps, components, or groups thereof. It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single 5 embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination. The embodiments described above are provided by way of example only, and various changes and modifications will be apparent to persons skilled in the art without departing 10 from the scope of the present invention as defined by the appended claims.

Claims

1. A sprocket carrier assembly for a kart, the sprocket carrier assembly comprising:a sprocket carrier having an inner body portion comprising an integrally formed first threaded connector and an outer body portion positioned radially outwardly of the inner body portion;at least one locator lug located on the outer body portion of the sprocket carrier, the or each locator lug being dimensioned to engage with an aperture of a sprocket to be carried; anda nut having a second threaded connector engageable with the first threaded connector to secure a sprocket to be carried in place.

2. A sprocket carrier assembly as claimed in claim 1, wherein the sprocket carrier has an axle engagement bore, the first and second threaded connectors having a diameter greater than that of the axle engagement bore.

3. A sprocket carrier assembly as claimed in claim 1 or claim 2, wherein the first threaded connector is a male threaded connector having an external thread and the second threaded connector is a female threaded connector having an internal thread.

4. A sprocket carrier assembly as claimed in any one of the preceding claims, wherein the at least one locator lug is releasably engageable with the sprocket carrier.

5. A sprocket carrier assembly as claimed in claim 4, wherein the at least one locator lug is threadingly engageable with a corresponding receiver of the outer body portion of the sprocket carrier.

6. A sprocket carrier assembly as claimed in claim 4 or claim 5, wherein a plurality of different locator lugs is provided, the plurality of locator lugs being selectably engageable with the sprocket carrier depending on the sprocket to be carried.

7. A sprocket carrier assembly as claimed in any one of the preceding claims, wherein the nut has an ergonomic outer perimeter.

8. A sprocket carrier assembly as claimed in any one of the preceding claims, wherein the sprocket carrier is a split sprocket carrier.

9. A sprocket carrier assembly as claimed in any one of the preceding claims, further comprising a secondary locking means for locking the nut to the sprocket carrier.

10. A sprocket carrier assembly as claimed in claim 9, wherein the secondary locking means is operable in a direction parallel to a direction of rotation of the sprocket carrier assembly in use.

11. A sprocket carrier assembly as claimed in claim 9 or claim 10, wherein the secondary locking means comprises a slot in the first threaded connector and a locking fastener for tightening the slot.

12. A sprocket carrier assembly as claimed in any one of the preceding claims, wherein the sprocket carrier is formed from a non-ferrous material.

13. A sprocket carrier assembly as claimed in any one of the preceding claims, wherein a centre of rotation of the nut is coincident with a central axis of the sprocket carrier.

14. A sprocket carrier assembly as claimed in any one of the preceding claims, wherein the nut defines a continuous annular contact surface for engagement with a sprocket, wear shim, or sprocket protector when carried by the sprocket carrier assembly.

15. A sprocket carrier assembly as claimed in any one of the preceding claims, further comprising a wear shim receivable between the sprocket carrier and the nut.

16. A sprocket carrier assembly as claimed in any one of the preceding claims, further comprising a sprocket protector.Application No: GB2404832.4Examiner: Mon WrightClaims searched: 1-16Date of search: 2 October 2024Patents Act 1977: Search Report under Section 17Documents considered to be relevant:Category Relevant to claims Identity of document and passage or figure of particular relevance X 1-9, 12-16 US 2007 / 0152420 Al (DELONG et al.) See whole document, noting sprocket carrier 10 with outer sprocket connection holes 12 for bolt / studs and inner connector neck portions 18, 19; and locking collar 30 which locks with neck portions by rotation (i.e. similar to a nut, but not threaded). A US 2024 / 0101214 Al (JASPER et al.) See in particular figure 22 and paragraphs [0041 ]-[0042], noting sprocket 328 with holes 342 for fasteners 340; sprocket carrier 338 with holes 346 and threaded connector 326 and nut 336 with threads 304. Not for go-kart, and threads don't seem to secure sprocket. A speedlockkart, 17 March 2008, "speed lock go kart sprocket hub", Youtube.com video, [online], Available from: https: / / www.youtube.com / watch?v=D-3F_yUUfoI [Accessed 2 Oct 2024] See in particular: at 0:14 sprocket hub with outer holes and an inner connector (possibly threaded?); at 0:18 blue sprocket with holes to align with outer holes, and from 0:20 onwards an annular connector part (possibly threaded?). [Note - video deemed too pixelated for clear X citation.] A enviolo, 1 May 2024, "How to install sprockets on enviolo hubs with a threaded freewheel", Youtube.com video [online], Available from: https: / / www.youtube.com / watch?v=MWXY_HzTiyA [Accessed 2 Oct 2024] See from 0:22 to 0:33: sprocket placed over a threaded section and then lock ring screwed onto this to hold sprocket in place. This is an example of a well-known lock-ring configuration for mounting sprockets in the art.Categories:X Document indicating lack of novelty or inventive step A Document indicating technological background and / or state of the art. Y Document indicating lack of inventive step if combined with one or more other documents of same category. P Document published on or after the declared priority date but before the filing date of this invention. & Member of the same patent family E Patent document published on or after, but with priority date earlier than, the filing date of this application.Field of Search:International Classification:Subclass Subgroup Valid From B60B 0027 / 04 01 / 01 / 2006 F16D 0001 / 076 01 / 01 / 2006 F16D 0001 / 08 01 / 01 / 2006 F16H 0055 / 30 01 / 01 / 2006

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