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US4765075A Expired / Lapsed US ⏱️ 0.0 years remaining

Water propulsion unit of water jet propulsion craft

Assignee: Yamaha Marine Co Ltd
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Filing: 1986-08-07
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Granted: 1988-08-23
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Expires: 2006-08-07
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Abstract

Abstract Several embodiments of water propulsion units for water jet propulsion crafts wherein an improved bearing support is provided for supporting an elongated drive shaft to permit the engine to be positioned well forwardly in the hull. In accordance with each embodiment, the bearing support member is elongated and is affixed rigidly to the jet propulsion unit in a radial direction for facilitating alignment.

Inventors

  • 👤 Ryoichi Nakase
  • 👤 Masayoshi Nanami

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 00:02
CPC Classifications
B; B63; B63H; B63H23/00; B63H23/32; B63H23/321; B63B; B63B34/00; B63B34/10; B63H2023/327

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 187 words
In a jet powered type of watercraft comprising a hull having an engine compartment containing an engine provided at the forward end thereof, a tunnel at the rearward end thereof, and a rider's area overlying said tunnel and adapted to accommodate a rider, a jet propulsion unit comprising an outer housing defining a water inlet, an impeller cavity and a discharge nozzle, an impeller journaled by said outer housing, said outer housing being carried by said hull and positioned at least in part in said tunnel substantially rearwardly of said engine compartment and rearwardly of said rider's area, a bulkhead separating said engine compartment from said tunnel, and means including a drive shaft driven by said engine for driving said impeller of said jet propulsion unit, the improvement comprising a bearing support tube radially fixed directly to said jet propulsion unit outer housing and extending forwardly therefrom through said bulkhead and into said hull and terminating adjacent said engine and bearing means fixed within said tube within said hull forwardly of said bulkhead and rotatably journaling said drive shaft contiguous to its drive connection to said engine.
Claim 2
Dependent Claim 187 words
In a jet powered type of watercraft comprising a hull having an engine compartment containing an engine provided at the forward end thereof, a tunnel at the rearward end thereof, and a rider's area overlying said tunnel and adapted to accommodate a rider, a jet propulsion unit comprising an outer housing defining a water inlet, an impeller cavity and a discharge nozzle, an impeller journaled by said outer housing, said outer housing being carried by said hull and positioned at least in part in said tunnel substantially rearwardly of said engine compartment and rearwardly of said rider's area, a bulkhead separating said engine compartment from said tunnel, and means including a drive shaft driven by said engine for driving said impeller of said jet propulsion unit, the improvement comprising a bearing support tube radially fixed directly to said jet propulsion unit outer housing and extending forwardly therefrom through said bulkhead and into said hull and terminating adjacent said engine and bearing means fixed within said tube within said hull forwardly of said bulkhead and rotatably journaling said drive shaft contiguous to its drive connection to said engine.
Claim 3
Dependent Claim 41 words
In a jet powered type of watercraft as set forth in claim 1 wherein the bearing support tube further supports a second bearing adjacent its connection to the outer housing for journaling said drive shaft contiguous to said jet propulsion unit.
Claim 4
Dependent Claim 26 words
In a jet powered type of watercraft as set forth in claim 1 wherein the jet propulsion unit is removable as a unit from the watercraft.
Claim 5
Dependent Claim 28 words
In a jet powered type of watercraft as set forth in claim 3 wherein the bearing support tube is removable as a unit with the jet propulsion unit.
Claim 6
Dependent Claim 43 words
In a jet powered type of watercraft as set forth in claim 1 and further including an elastic seal interposed between the bearing support tube and the bulkhead for preventing the ingress of water through said tunnel into the interior of said hull.
Claim 7
Dependent Claim 42 words
In a jet powered type of watercraft as set forth in claim 2 further including an elastic seal interposed between the bearing support tube and the bulkhead for preventing the ingress of water through said tunnel into the interior of said hull.
Claim 8
Dependent Claim 42 words
In a jet powered type of watercraft as set forth in claim 4 further including an elastic seal interposed between the bearing support tube and the bulkhead for preventing the ingress of water through said tunnel into the interior of said hull.

References Cited (Backward Citations)

US3324822A Cited
US3827392A Cited
US3859951A Cited
GB2061851A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1991-08-23 1992-02-22 1992-08-23 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1995-08-23 1996-02-22 1996-08-23 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1999-08-23 2000-02-22 2000-08-23 $7700.00 Window Closed / Lapsed

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