# US 2021/0277986 A1 · Apparatus for securing a sprocket to a sprocket carrier > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0277986 A1 - Document ID: US20210277986A1 - Status: Published application - Kind: A1 - Application number: 17/264,285 - Filed: 2019-08-09 - Published: 2021-09-09 - Earliest claimed: 2018-08-09 - Inventors: James HOBBS; Lee Michele CIARDI - Web page: https://patentgrep.com/patent/US20210277986A1 ## CPC - F16D 1/076: by clamping together two faces perpendicular to the axis of rotation, e.g. with bolted flanges - F16H 55/30: Chain-wheels - F16B 35/041: {Specially-shaped shafts (shape of thread F16B33/02)} - F16H 55/10: Constructively simple tooth shapes, e.g. shaped as pins, as balls - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES - F16H: GEARING - F16B: DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING (couplings for transmitting rotation F16D) ## Abstract A sprocket assembly (101) comprises a sprocket carrier (102), a sprocket (103), and a plurality of fixing devices (104) for use in securing the sprocket (103) to the sprocket carrier (102). Each fixing device (104) comprises a bolt (601) and a nut (602), the nut (602) engageable with a threaded shank portion (604) of the bolt (601), and the bolt (601) insertable through a fixing aperture (401) of the sprocket carrier (102) into a fitted condition in which the bolt (601) is retained within the sprocket carrier (102) by an interference fit between a knurled shank portion (605) of the bolt (601) and the sprocket carrier (102). A sprocket (103), a sprocket carrier (102), and a sprocket protector (106) for use within the sprocket assembly (101). ## Claims ### Claim 1 A sprocket assembly, comprising: a sprocket carrier, the sprocket carrier defining a plurality of fixing apertures for use in securing a sprocket to the sprocket carrier, a sprocket, the sprocket defining a plurality of fixing apertures for use in securing the sprocket to a sprocket carrier, and a securing arrangement for releasably securing the sprocket to the sprocket carrier; wherein said securing arrangement comprises a plurality of fixing devices; each of said plurality of fixing devices comprises a bolt and a nut, the bolt having a head portion, a threaded shank portion and a knurled shank portion, the knurled shank portion disposed between the threaded shank portion and the head portion, and the nut engageable with the threaded shank portion of the bolt; the bolt of each of said plurality of fixing devices insertable through one of the plurality of fixing apertures of the sprocket carrier into a fitted condition in which the bolt is retained within the sprocket carrier by an interference fit between the knurled shank portion of the bolt and the sprocket carrier. ### Claim 2 (depends on 1) The sprocket assembly of claim 1, wherein said sprocket defines a plurality of first fixing apertures for use in releasably securing the sprocket to the sprocket carrier, each of said plurality of first fixing apertures of the sprocket comprises a first portion and a second portion, the second portion extending in a first circumferential direction from the first portion, the first portion shaped to allow the passage of a nut of one of the plurality of fixing devices therethrough and the second portion shaped to prevent the passage of said nut of said one of the plurality of fixing devices therethrough. ### Claim 3 (depends on 2) The sprocket assembly of claim 2, wherein said first portion is a generally round portion and said second portion is a generally linear portion. ### Claim 4 (depends on 2) The sprocket assembly of claim 2, wherein said sprocket defines a plurality of second fixing apertures, each of said plurality of second fixing apertures comprising a single circular portion. ### Claim 5 (depends on 4) The sprocket assembly of claim 4, wherein said plurality of first fixing apertures comprises three first fixing apertures, said plurality of second fixing apertures comprises three second fixing apertures, and the three first fixing apertures and the three second fixing apertures are spaced about a virtual circumference of said sprocket and are distributed around the virtual circumference in an alternating pattern. ### Claim 6 (depends on 1) The sprocket assembly of claim 1, wherein said sprocket is a split sprocket. ### Claim 7 (depends on 1) The sprocket assembly of claim 1, further comprising a sprocket protector, wherein said sprocket protector defines a plurality of fixing apertures for use in releasably securing the sprocket protector to the sprocket carrier, each of said plurality of fixing apertures of the sprocket protector comprises a first portion and a second portion, the second portion extending in a first circumferential direction from the first portion, the first portion shaped to allow the passage of a nut of one of the plurality of fixing devices therethrough and the second portion shaped to prevent the passage of said nut of said one of the plurality of fixing devices therethrough. ### Claim 8 (depends on 7) The sprocket assembly of claim 7, further comprising a second sprocket protector, wherein: the sprocket carrier has a first side and a second side, the second side opposite the first side; the sprocket is configured to be mounted to the sprocket carrier from the first side thereof, the sprocket protector is configured to be mounted to the sprocket carrier from the first side thereof, and the second sprocket protector is configured to be mounted to the sprocket carrier from the second side thereof. ### Claim 9 (depends on 1) The sprocket assembly of claim 1, wherein each of said plurality of fixing devices comprises a second nut, said threaded shank portion is disposed on a first side of the head portion and the bolt further comprises a second threaded shaft portion that is disposed on a second side of the head portion, the second side opposite said first side, said second nut engageable with the second threaded shaft portion of the bolt. ### Claim 10 (depends on 1) The sprocket assembly of claim 1, wherein the sprocket carrier is a sprocket hub for the rear sprocket of a racing kart. ### Claim 11 (depends on 1) A sprocket for use in the sprocket assembly of claim 1, wherein said sprocket defines a plurality of first fixing apertures for use in releasably securing the sprocket to a sprocket carrier, and further defines a second plurality of second fixing apertures, each of said plurality of first fixing apertures is generally key-hole shaped and comprises a first generally round portion having a centre and a second generally linear portion, the second portion extending in a first circumferential direction from the first portion, the first portion shaped to allow the passage of a nut of one of the plurality of fixing devices therethrough and the second portion shaped to prevent the passage of said nut of said one of the plurality of fixing devices therethrough, each of said plurality of second fixing apertures is generally circle-shaped and comprises a single circular portion having a centre, and the centres of the generally round first portions of the first fixing apertures and the centres of the generally circular portions of the second fixing apertures are spaced equidistantly around a virtual circumference of the sprocket, with the first fixing apertures and the second fixing apertures distributed around the virtual circumference in an alternating pattern. ### Claim 12 (depends on 1) A sprocket protector for use in the sprocket assembly of claim 1, wherein said sprocket protector defines a plurality of fixing apertures for use in releasably securing the sprocket protector to the sprocket carrier, each of said plurality of fixing apertures of the sprocket protector comprises a first portion and a second portion, the second portion extending in a first circumferential direction from the first portion, the first portion shaped to allow the passage of a nut of one of the plurality of fixing devices therethrough and the second portion shaped to prevent the passage of said nut of said one of the plurality of fixing devices therethrough. ### Claim 13 (depends on 1) A sprocket carrier for use in the sprocket assembly of claim 1, wherein the sprocket carrier defines a plurality of fixing apertures for use in securing a sprocket to the sprocket carrier, and the sprocket carrier is provided with a plurality of fixing devices; each of said plurality of fixing devices comprising a bolt and a nut, the bolt having a head portion, a threaded shank portion and a knurled shank portion, the knurled shank portion disposed between the threaded shank portion and the head portion, and the nut engageable with the threaded shank portion of the bolt; and the bolt of each of said plurality of fixing devices inserted through one of the plurality of fixing apertures of the sprocket carrier into a fitted condition in which the bolt is retained within the sprocket carrier by an interference fit between the knurled shank portion of the bolt and the sprocket carrier. ### Claim 14 (depends on 1) A vehicle provided with the sprocket assembly of claim 1. ### Claim 15 (depends on 14) A vehicle as claimed in claim 14, wherein said vehicle is a racing kart. ### Claim 16 (depends on 2) The sprocket assembly of claim 2, wherein said sprocket is a split sprocket. ### Claim 17 (depends on 3) The sprocket assembly of claim 3, wherein said sprocket defines a plurality of second fixing apertures, each fixing aperture of said plurality of second fixing apertures comprising a single circular portion. ### Claim 18 (depends on 17) The sprocket assembly of claim 17, wherein said plurality of fixing apertures comprises three fixing apertures, said second plurality of fixing apertures comprises three fixing apertures, and the three fixing apertures of said plurality of fixing apertures and the three fixing apertures of said second plurality of fixing apertures are spaced about a virtual circumference of said sprocket and are distributed around the virtual circumference in an alternating pattern. ### Claim 19 (depends on 11) The sprocket of claim 11, wherein said plurality of first fixing apertures comprises three fixing apertures and said plurality of second fixing apertures comprises three fixing apertures. ### Claim 20 (depends on 11) The sprocket of claim 11, wherein said sprocket is a split sprocket.