# US 7,410,397 B2 · Outboard motor with bracket assembly > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,410,397 B2 - Document ID: US7410397B2 - Status: Granted - Kind: B2 - Application number: 11/125,823 - Filed: 2005-05-10 - Published: 2005-11-24 - Granted: 2008-08-12 - Earliest claimed: 2004-05-10 - Assignees: Yamaha Marine Kabushiki Kaisha - Inventors: Daisuke Nakamura; Isao Fujii; Masayuki Arito; Masayoshi Sawamura - Web page: https://patentgrep.com/patent/US7410397B2 ## CPC - B63H 20/12: Means enabling steering - B63H 20/06: on an intermediate support - B63H 20/08: Means enabling movement of the position of the propulsion element, e.g. for trim, tilt or steering; Control of trim or tilt (initiating means for steering B63H25/02) - B63H: MARINE PROPULSION OR STEERING (propulsion of air-cushion vehicles B60V1/14; specially adapted for submarines, other than nuclear propulsion, B63G; specially adapted for torpedoes F42B19/00) ## Abstract An outboard motor includes a bracket assembly that has a swivel bracket carrying a drive unit for pivotal movement about a steering axis that extends generally vertically. The swivel bracket has a tubular section that extends generally vertically. The drive unit has a steering member that includes a steering shaft section extending through the tubular section and defining the steering axis. The steering shaft section has top and bottom portions out of the tubular section. The steering shaft section further has an upper portion below the top portion within the tubular section, and a lower portion above the bottom portion within the tubular section. The tubular section has upper, lower and middle bushings. The upper and lower bushings pivotally support the upper and lower portions, respectively. The middle bushing pivotally supports a middle portion of the steering shaft section between the upper and lower portions. ## Claims ### Claim 1 An outboard motor comprising a drive unit, and a bracket assembly adapted to mount the drive unit on an associated watercraft, the bracket assembly including a swivel bracket carrying the drive unit for pivotal movement about a steering axis that extends generally vertically, the swivel bracket having a tubular section that extends generally vertically, the drive unit having a steering member that includes a steering shaft section, the steering shaft section extending through the tubular section of the swivel bracket and defining the steering axis, the steering shaft section having top and bottom portions that exposed beyond at least a portion of the tubular section, the top and bottom portions being attached to the drive unit, the steering shaft section further having an upper portion below the top portion within the tubular section, and a lower portion above the bottom portion within the tubular section, the tubular section including upper, lower and middle bushings, the upper bushing pivotally supporting the upper portion of the steering shaft section, the lower bushing pivotally supporting the lower portion of the steering shaft section, and the middle bushing pivotally supporting a middle portion of the steering shaft section between the upper and lower portions without any locking mechanism or clutch disposed between the tubular section and the steering shaft and between the upper and lower bushings. ### Claim 2 (depends on 1) The outboard motor as set forth in claim 1, wherein the tubular section of the swivel bracket and the steering shaft section of the steering member defines an upper space therebetween above the middle bushing, the tubular section of the swivel bracket and the steering shaft section of the steering member defines a lower space therebetween below the middle bushing, and at least the middle bushing defining a passage through which the upper and lower spaces communicates with each other. ### Claim 3 (depends on 2) The outboard motor as set forth in claim 2, wherein the middle bushing and either the tubular section or the steering shaft section together define the passage. ### Claim 4 (depends on 2) The outboard motor as set forth in claim 2, wherein the middle bushing, the tubular section and the steering shaft section together define the passage. ### Claim 5 (depends on 2) The outboard motor as set forth in claim 2, wherein the middle bushing has a slit that defines the passage. ### Claim 6 (depends on 2) The outboard motor as set forth in claim 2, wherein the tubular section of the swivel bracket having a lubricant inlet configured to permit lubricant to be supplied to at least one of the upper and lower spaces. ### Claim 7 (depends on 6) The outboard motor as set forth in claim 6, wherein the lubricant inlet is generally formed on a lateral side portion of the tubular section. ### Claim 8 (depends on 7) The outboard motor as set forth in claim 7, wherein the bracket assembly further includes a clamping bracket supporting the swivel bracket and the drive unit for pivotal movement about a tilt axis extending generally horizontally, and a hypothetical line generally intersecting the steering axis at right angles and generally extending parallel to the tilt axis passes through the lateral side portion of the tubular section. ### Claim 9 (depends on 1) The outboard motor as set forth in claim 1, wherein the steering shaft section has an inner surface that is tapered toward the middle portion from the upper or lower portion. ### Claim 10 (depends on 9) The outboard motor as set forth in claim 9, wherein the steering shaft section has an outer surface that is tapered toward the middle portion from the upper or lower portion. ### Claim 11 (depends on 9) The outboard motor as set forth in claim 9, wherein the inner surface is tapered toward the middle portion from both the upper and lower portions over a substantial portion of its length. ### Claim 12 (depends on 1) The outboard motor as set forth in claim 1, wherein the bracket assembly further includes a clamping bracket supporting the swivel bracket and the drive unit for pivotal movement about a tilt axis extending generally horizontally, the steering member further includes a steering lever section that extends generally forward from the top portion of the steering shaft section, and the steering lever section comprises a web portion extending generally parallel to the tilt axis and at least one portion extending generally normal to the web portion. ### Claim 13 (depends on 1) The outboard motor as set forth in claim 1, wherein at least one of the bushings is configured to be inserted into the tubular section. ### Claim 14 (depends on 13) The outboard motor as set forth in claim 13, wherein the bushings are sealed within the tubular section. ### Claim 15 An outboard motor comprising a drive unit, and a bracket assembly adapted to mount the drive unit on an associated watercraft, the bracket assembly including a swivel bracket carrying the drive unit for pivotal movement about a steering axis that extends generally vertically, the swivel bracket having a tubular section that extends generally vertically, the drive unit having a steering member that includes a steering shaft section, the steering shaft section extending through the tubular section of the swivel bracket and defining the steering axis, the steering shaft section including an upper portion, a middle portion and a lower portion, the middle portion being positioned between the upper and lower portions, and the steering shaft section having at least a first inner surface extending from the upper portion to the middle portion and at least a second inner surface extending from the lower portion to the middle portion, each of the first and second inner surfaces being tapered over approximately half of its length. ### Claim 16 (depends on 15) The outboard motor as set forth in claim 15, wherein the steering shaft section has an outer surface that is tapered toward the middle portion from the upper or lower portion. ### Claim 17 (depends on 16) The outboard motor as set forth in claim 16, wherein a thickness of the steering shaft section in a tapered area where the inner and outer surfaces are tapered toward the middle portion is generally constant. ### Claim 18 (depends on 15) The outboard motor as set forth in claim 15, wherein the steering member is produced in a vacuum die-casting process. ### Claim 19 An outboard motor comprising a drive unit, and a bracket assembly adapted to mount the drive unit on an associated watercraft, the bracket assembly including a swivel bracket carrying the drive unit for pivotal movement about a steering axis that extends generally vertically, the swivel bracket having a tubular section that extends generally vertically, the drive unit having a steering member that includes a steering shaft section, the steering shaft section extending through the tubular section of the swivel bracket and defining the steering axis, the steering shaft section including an upper portion, a middle portion and a lower portion, the middle portion being positioned between the upper and lower portions, and the steering shaft section having at least a first inner surface extending from the upper portion to the middle portion and at least a second inner surface extending from the lower portion to the middle portion, at least one of the first and second inner surfaces being tapered over at least half of its length, wherein the tubular section of the swivel bracket has upper, lower and middle bushings, the upper bushing pivotally supports the upper portion of the steering shaft section, the lower bushing pivotally supports the lower portion of the steering shaft section, and the middle bushing pivotally supports the middle portion of the steering shaft section. ### Claim 20 An outboard motor comprising a drive unit, and a bracket assembly adapted to mount the drive unit on an associated watercraft, the bracket assembly including a swivel bracket carrying the drive unit for pivotal movement about a steering axis that extends generally vertically, the swivel bracket having a tubular section that extends generally vertically, the drive unit having a steering member that includes a steering shaft section, the steering shaft section extending through the tubular section of the swivel bracket and defining the steering axis, the steering shaft section including an upper portion, a middle portion and a lower portion, the middle portion being positioned between the upper and lower portions, and the steering shaft section having at least a first inner surface extending from the upper portion to the middle portion and at least a second inner surface extending from the lower portion to the middle portion, at least one of the first and second inner surfaces being tapered over at least half of its length, wherein the bracket assembly further includes a clamping bracket supporting the swivel bracket and the drive unit for pivotal movement about a tilt axis extending generally horizontally, the steering shaft section further includes a top portion above the upper portion, the steering member further includes a steering lever section that extends generally forward from the top portion of the steering shaft section, the steering lever section comprises a web portion extending generally parallel to the tilt axis and at least one reinforcing portion extending generally normal to the web portion. ### Claim 21 An outboard motor comprising a drive unit, and a bracket assembly adapted to mount the drive unit on an associated watercraft, the bracket assembly including a swivel bracket carrying the drive unit for pivotal movement about a steering axis that extends generally vertically, the swivel bracket having a tubular section that extends generally vertically, the drive unit having a steering member that includes a steering shaft section, the steering shaft section extending through the tubular section of the swivel bracket and defining the steering axis, the steering shaft section having top and bottom portions that exposed beyond at least a portion of the tubular section, the top and bottom portions being attached to the drive unit, the steering shaft section further having an upper portion below the top portion within the tubular section, and a lower portion above the bottom portion within the tubular section, the tubular section including upper, lower and middle bushings, the upper bushing pivotally supporting the upper portion of the steering shaft section, the lower bushing pivotally supporting the lower portion of the steering shaft section, and the middle bushing contacting and pivotally supporting a middle portion of the steering shaft section between the upper and lower portions, without any clutch disposed between the tubular section and the steering shaft and between the upper and lower bushings. ### Claim 22 (depends on 21) The outboard motor as set forth in claim 21, wherein the steering shaft section has an inner surface, the inner surface tapering from the upper portion toward the middle portion over a majority of a distance between the upper portion and the middle portion, and the inner surface tapering from the lower portion toward the middle portion over a majority of a distance between the lower portion and the middle portion. ### Claim 23 An outboard motor comprising a drive unit, and a bracket assembly adapted to mount the drive unit on an associated watercraft, the bracket assembly including a swivel bracket carrying the drive unit for pivotal movement about a steering axis that extends generally vertically, the swivel bracket having a tubular section that extends generally vertically, the drive unit having a steering member that includes a steering shaft section, the steering shaft section extending through the tubular section of the swivel bracket and defining the steering axis, the steering shaft section having top and bottom portions that exposed beyond at least a portion of the tubular section, the top and bottom portions being attached to the drive unit, the steering shaft section further having an upper portion below the top portion within the tubular section, and a lower portion above the bottom portion within the tubular section, the tubular section including upper, lower and middle bushings, the upper bushing pivotally supporting the upper portion of the steering shaft section, the lower bushing pivotally supporting the lower portion of the steering shaft section, and the middle bushing pivotally supporting a generally circular middle portion of the steering shaft section between the upper and lower portions, without any clutch disposed between the tubular section and the steering shaft and between the upper and lower bushings. ### Claim 24 (depends on 23) The outboard motor as set forth in claim 23, wherein the steering shaft section has an inner surface, the inner surface tapering from the upper bushing toward the middle bushing over a majority of a distance between the upper bushing and the middle bushing, and the inner surface tapering from the lower bushing toward the middle bushing over a majority of a distance between the lower bushing and the middle bushing. ### Claim 25 An outboard motor comprising a drive unit, and a bracket assembly adapted to mount the drive unit on an associated watercraft, the bracket assembly including a swivel bracket carrying the drive unit for pivotal movement about a steering axis that extends generally vertically, the swivel bracket having a tubular section that extends generally vertically, the drive unit having a steering member that includes a steering shaft section, the steering shaft section extending through the tubular section of the swivel bracket and defining the steering axis, the steering shaft section having top and bottom portions that exposed beyond at least a portion of the tubular section, the top and bottom portions being attached to the drive unit, the steering shaft section further having an upper portion below the top portion within the tubular section, and a lower portion above the bottom portion within the tubular section, the tubular section including upper, lower and middle bushings, the upper bushing pivotally supporting the upper portion of the steering shaft section, the lower bushing pivotally supporting the lower portion of the steering shaft section, and the middle bushing pivotally supporting a middle portion of the steering shaft section between the upper and lower portions, wherein the tubular section of the swivel bracket and the steering shaft section of the steering member defines an upper space therebetween above the middle bushing, the tubular section of the swivel bracket and the steering shaft section of the steering member defines a lower space therebetween below the middle bushing, and at least the middle bushing defining a passage through which the upper and lower spaces communicates with each other, without any clutch disposed between the tubular section and the steering shaft and between the upper and lower bushings. ### Claim 26 (depends on 25) The outboard motor as set forth in claim 25, wherein the steering shaft section has an inner surface that tapers over approximately half of its length from the upper portion toward the middle portion, and over approximately half of its length from the lower portion toward the middle portion.