GB2295805A - Counter-rotating surfacing marine drive with reduced drag water line - Google Patents

Counter-rotating surfacing marine drive with reduced drag water line Download PDF

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Publication number
GB2295805A
GB2295805A GB9604560A GB9604560A GB2295805A GB 2295805 A GB2295805 A GB 2295805A GB 9604560 A GB9604560 A GB 9604560A GB 9604560 A GB9604560 A GB 9604560A GB 2295805 A GB2295805 A GB 2295805A
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United Kingdom
Prior art keywords
propeller shaft
propeller
bore
plane
housing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB9604560A
Other versions
GB9604560D0 (en
GB2295805B (en
Inventor
Jr Charles F Alexander
Daniel F Mccormick
Gary L Meisenburg
Phillip D Magee
Edward C Eick
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Brunswick Corp
Original Assignee
Brunswick Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Brunswick Corp filed Critical Brunswick Corp
Priority claimed from GB9412860A external-priority patent/GB2279308B/en
Publication of GB9604560D0 publication Critical patent/GB9604560D0/en
Publication of GB2295805A publication Critical patent/GB2295805A/en
Application granted granted Critical
Publication of GB2295805B publication Critical patent/GB2295805B/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63H—MARINE PROPULSION OR STEERING
    • B63H20/00—Outboard propulsion units, e.g. outboard motors or Z-drives; Arrangements thereof on vessels
    • B63H20/08—Means enabling movement of the position of the propulsion element, e.g. for trim, tilt or steering; Control of trim or tilt
    • B63H20/10—Means enabling trim or tilt, or lifting of the propulsion element when an obstruction is hit; Control of trim or tilt
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63H—MARINE PROPULSION OR STEERING
    • B63H20/00—Outboard propulsion units, e.g. outboard motors or Z-drives; Arrangements thereof on vessels
    • B63H20/14—Transmission between propulsion power unit and propulsion element
    • B63H20/22—Transmission between propulsion power unit and propulsion element allowing movement of the propulsion element about at least a horizontal axis without disconnection of the drive, e.g. using universal joints
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63H—MARINE PROPULSION OR STEERING
    • B63H5/00—Arrangements on vessels of propulsion elements directly acting on water
    • B63H5/07—Arrangements on vessels of propulsion elements directly acting on water of propellers
    • B63H5/08—Arrangements on vessels of propulsion elements directly acting on water of propellers of more than one propeller
    • B63H5/10—Arrangements on vessels of propulsion elements directly acting on water of propellers of more than one propeller of coaxial type, e.g. of counter-rotative type
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63H—MARINE PROPULSION OR STEERING
    • B63H20/00—Outboard propulsion units, e.g. outboard motors or Z-drives; Arrangements thereof on vessels
    • B63H20/001—Arrangements, apparatus and methods for handling fluids used in outboard drives
    • B63H20/002—Arrangements, apparatus and methods for handling fluids used in outboard drives for handling lubrication liquids
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63H—MARINE PROPULSION OR STEERING
    • B63H20/00—Outboard propulsion units, e.g. outboard motors or Z-drives; Arrangements thereof on vessels
    • B63H20/24—Arrangements, apparatus and methods for handling exhaust gas in outboard drives, e.g. exhaust gas outlets
    • B63H20/26—Exhaust gas outlets passing through the propeller or its hub
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63H—MARINE PROPULSION OR STEERING
    • B63H20/00—Outboard propulsion units, e.g. outboard motors or Z-drives; Arrangements thereof on vessels
    • B63H20/28—Arrangements, apparatus and methods for handling cooling-water in outboard drives, e.g. cooling-water intakes
    • B63H20/285—Cooling-water intakes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63H—MARINE PROPULSION OR STEERING
    • B63H1/00—Propulsive elements directly acting on water
    • B63H1/02—Propulsive elements directly acting on water of rotary type
    • B63H1/12—Propulsive elements directly acting on water of rotary type with rotation axis substantially in propulsive direction
    • B63H1/14—Propellers
    • B63H1/18—Propellers with means for diminishing cavitation, e.g. supercavitation
    • B63H2001/185—Surfacing propellers, i.e. propellers specially adapted for operation at the water surface, with blades incompletely submerged, or piercing the water surface from above in the course of each revolution
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63H—MARINE PROPULSION OR STEERING
    • B63H20/00—Outboard propulsion units, e.g. outboard motors or Z-drives; Arrangements thereof on vessels
    • B63H2020/005—Arrangements of two or more propellers, or the like on single outboard propulsion units
    • B63H2020/006—Arrangements of two or more propellers, or the like on single outboard propulsion units of coaxial type, e.g. of counter-rotative type

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • Ocean & Marine Engineering (AREA)
  • Sliding-Contact Bearings (AREA)

Abstract

In a marine drive 10 having two counter-rotating surface operating propellers 12 and 14, a drive housing 20 having upper and lower horizontal bores 22 and 24 and an intersecting vertical bore 26 therebetween, the housing 20 has a lower horizontal torpedo portion 188 around the lower horizontal bore 24. The housing 20 has a skeg 194 extending downwardly below the torpedo 188, and a water intake 192 is provided in the skeg 194. The water line is above the water intake 192, and the bottom of the torpedo 188 is at or above the plane 230 of the bottom 190 of the boat 18. In a given trimmed-in condition (Fig. 5) the torpedo 188 extends at an upward angle from the aft end thereof, and the bottom of the propeller hubs 232, 234 define a horizontal line at or above the noted plane 230. <IMAGE>

Description

COUNTER-ROTATING SURFACING MARINE DRIVE WITH REDUCED DRAG WATER LINE CROSS REFERENCE TO RELATED APPLICATIONS This application is related to allowed U.S. patent applications S.N. 07/889,495 and S.N. 07/889,530, corresponding to GB-A-2267264 and GB-A-2267686 respectively, incorporated herein by reference.
BACKGROUND AND SUMMARY The invention relates to a marine drive having two counter-rotating surface operating propellers.
The present invention arose during development efforts directed toward a marine drive enabling increased top end boat speed. This is achieved by raising the torpedo or gear box out of the water to reduce drag, and by using two counter-rotating surface operating propellers. Surfacing drives are known in the art, for example U.S. Patent 4,871,334, column 3, lines 35+.
The present invention provides structure enabling a reduced drag dual propeller surfacing drive by operating the gearcase torpedo completely above the water surface at high speed.
BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a side elevation view of a marine drive in accordance with the invention.
Fig. 2 is a partial sectional view of a portion of the structure of Fig. 1.
Fig. 3 is an enlarged view of a portion of the structure of Fig. 2.
Fig. 4 is an exploded perspective view of a portion of the structure of Fig. 1.
Fig. 5 is like Fig. 1 but shows a trimmed-in condition.
DETAILED DESCRIPTION Fig. 1 shows a marine drive 10 having two counter-rotating surface operating propellers 12 and 14.
The drive is mounted to the transom 16 of a boat 18 in the usual manner for a stern drive. The drive includes a housing 20, Fig. 2, having upper and lower spaced horizontal bores 22 and 24, and an intersecting vertical bore 26 extending therebetween. An upper input shaft 28 is in upper horizontal bore 22 and is coupled through a universal joint 30 to an input shaft 32 driven by the engine (not shown) in the boat. The universal joint enables trimming and steering of the drive. The input shaft drives an upper gear assembly 34 which is known in the art, for example as shown in U.S. Patents 4,630,719, 4,679,682, and 4,869,121, incorporated herein by reference. A downwardly extending driveshaft 36 in vertical bore 26 is driven by input shaft 28 through upper gear assembly 34 operatively connected therebetween.Input gear 38 on shaft 28 rotates about a horizontal axis and drives gears 40 and 42 to rotate in opposite directions about a vertical axis. Shift and clutch assembly 44 causes engagement of one or the other of gears 40 and 42, to in turn cause rotation of driveshaft 36 in one or the other direction, to provide forward or reverse operation, all as in the noted incorporated patents.
Vertical bore 26 has an upper threaded portion 46, Fig. 3. An upper adaptor spool 48 has a lower threaded outer portion 50 mating with threaded portion 46 of vertical bore 26 and supporting gear 42 for rotation about driveshaft 36. Adaptor spool 48 has an upper outer surface 52 supporting an upper outer needle bearing 54 which supports gear 42 for rotation about adaptor spool 48. Adaptor spool 48 has an upper inner surface 56 supporting an upper inner needle bearing 58 which supports driveshaft 36 for rotation in adaptor spool 48.
Adaptor spool 48 has a lower outer section 60, Fig. 3, of a first outer diameter 62 and threaded as noted at 50 and mating with upper threaded portion 46 of vertical bore 26. Adaptor spool 48 has a central outer section 64 above lower outer section 60 and of a central outer diameter 66 larger than lower outer diameter 62.
Adaptor spool 48 has an upper outer section 68 above central outer section 64 and of an upper outer diameter 70 less than central outer diameter 66 and less than lower outer diameter 62. Adaptor spool 48 has a lower inner section 72 of a lower inner diameter 74 within vertical bore 26. Adaptor spool 48 has an upper inner section 76 above lower inner section 72 and of an upper inner diameter 78 less than lower inner diameter 74.
Upper outer needle bearing 54 is between gear 42 and upper outer section 68 of adaptor spool 48 and supports gear 42 for rotation about adaptor spool 48. Upper inner needle bearing 58 is between driveshaft 36 and upper inner section 76 of adaptor spool 48 and supports driveshaft 36 for rotation in adaptor spool 48. Lower outer section 60-and central outer section 64 of adaptor spool 48 meet at a downwardly facing annular shoulder 80 at the top end 82 of housing sidewall 84 forming vertical bore 26. Upper outer diameter 70 is substantially equal to lower inner diameter 74 of adaptor spool 48.
Vertical bore 26 has a first section 86, Fig.
3, of a first inner diameter 88. Vertical bore 26 has a second section 90 above first section 86 and of a second inner diameter 92 larger than inner diameter 88. Sections 86 and 90 meet at an upwardly facing annular shoulder 94. Vertical bore 26 has a first thread 96 above second section 90 and of an inner diameter 98 at least as great as second inner diameter 92. Vertical bore 26 has a third section 100 above first thread 96 and of a third inner diameter 102 greater than second inner diameter 98.
Vertical bore 26 has a second thread, provided by the noted thread 46, above third section 100 and of an inner diameter 104 at least as great as third inner diameter 102. A central tapered roller thrust bearing 106 is seated against shoulder 94 of vertical bore 26. An annular ring 108 has a threaded outer portion 110 mating with thread 96 of vertical bore 26 and retains bearing 106 against shoulder 94. Vertical bore 26 has a fourth section 112 below first section 86 and of a fourth inner diameter 114 larger than first inner diameter 88. First and fourth sections 86 and 112 meet at a downwardly facing annular shoulder 116. A lower needle bearing 118 is seated against downwardly facing shoulder 116 and supports driveshaft 36 for rotation. Central and upper bearings 106 and 58 are inserted into vertical bore 26 from above, Fig. 4.Lower bearing 118 is inserted into vertical bore 26 from below.
Driveshaft 36, Fig. 3, is a two piece member formed by an upper driveshaft segment 120 and a lower driveshaft segment 122 coupled by a sleeve 124 in splined relation. Central bearing 106 and lower bearing 118 support the lower driveshaft segment 122. Upper bearing 58 supports the upper driveshaft segment 120. The upper driveshaft segment is also supported by another upper needle bearing 126, Fig. 2, as in the noted incorporated patents.
Driveshaft 36 has a lower pinion gear 128, Fig.
3, mounted thereto by bolt 130 and washer 132. Needle bearing 118 is above pinion gear 128 and is supported between inner and outer races 134 and 136. Outer race 136 engages shoulder 116, and inner race 134 engages shoulder 138 on lower driveshaft segment 122. Bearing 106 has an inner race 140 engaging shoulder 142 on lower driveshaft segment 122. Bearing 106 has an outer race 144 stopped against shoulder 94 in bore 26. One or more shims 146 may be provided between outer race 144 and shoulder 94 to adjust axial positioning if desired. Gear 42 rotates on bearing 148 on race 150 seated on shoulder 152 of housing sidewall 154.
A pair of lower concentric counter-rotating inner and outer propeller shafts 156 and 158, Fig. 2, in lower horizontal bore 24 are driven by driveshaft 36.
Inner propeller shaft 156 has a fore gear 160 driven by pinion gear 128 to drivingly rotate inner propeller shaft 156. Outer propeller shaft 158 has an aft. gear 162 driven by pinion gear 128 to drivingly rotate outer propeller shaft 158 in the opposite rotational direction than inner propeller shaft 156. Reference is made to allowed incorporated U.S. application S.N. 07/889,530, filed May 27, 1992. The dual propeller shaft assembly is mounted in horizontal bore 24 by a spool assembly 164 at right hand threads 166 and retaining ring 168 having left hand threads 170. The right hand threads prevent right hand rotational loosening of the spool assembly, and the left hand threads 170 prevent left hand rotational loosening of the spool assembly.Forward thrust is transferred from the outer propeller shaft 158 to the inner propeller shaft 156 at thrust bearing 172 against annular shoulder 174 on inner propeller shaft 156. Propeller 12 is mounted on inner propeller shaft 156 in splined relation at 176 between tapered ring 178 and threaded nut 180. Propeller 14 is mounted on outer propeller shaft 158 in splined relation at 182 between tapered ring 184 and threaded nut 186.
The vertical distance between adaptor spool 48 and lower bearing 118 is about equal to the radius of propellers 12 and 14. Lower horizontal bore 24 of housing 20 is in the portion commonly called the torpedo 188, FIGS. 1 and 4. Torpedo 188 is slightly above the bottom 190 of boat 18 and hence is slightly above the surface of the water, thus reducing drag. This raising of the torpedo above the surface of the water is accomplished without a like raising of the engine in the boat nor the usual transom mounting location for the drive. In the preferred embodiment, the engine is raised 2 to 3 inches above its standard location. Housing 20 is a one-piece unitary integrally cast housing replacing prior two piece housings. Propeller shafts 156, 158 are spaced from upper input shaft 28 by a distance along driveshaft 36 in the range of about 8 to 15 inches.
Cooling water for the engine is supplied through water intake 192 in skeg 194, and flows through skeg passage 196 and then through torpedo nose passage 198 and then through housing passage 200 to the engine in the usual manner. After cooling the engine, the water and engine exhaust are exhausted in the usual manner through an exhaust elbow and exhausted through the housing and discharged at exhaust outlet 202 above torpedo 188 and into the path of the propellers in the upper portion of their rotation, as in U.S. Patent 4,871,334.
Oil is circulated from the lower gears upwardly through passage 204 and passage 206 to the upper gears, and returned to the lower gears at passage 208 feeding passages 210 and 212. Oil is supplied from passage 210 through spool assembly passage 214 to bearings 216 and 218, and through outer propeller shaft passage 220 to bearing 222. Passage 212 supplies oil to the front of bearing 218. Central outer section 64 of adaptor spool 48 closes off oil passage 204, to divert flow to passage 206.
In the preferred embodiment, torpedo or gear box 188 is raised such that it is entirely above the water surface during high speed operation with the boat on plane. Torpedo 188 is entirely above the plane 230 of the bottom of boat 18 when propeller shafts 156 and 158 are parallel to plane 230. The bottom of torpedo 188 is at or above plane 230 during high speed operation.
Respective propellers 12 and 14 are mounted by respective propeller hubs 232 and 234 to respective propeller shafts 156 and 158. The bottom of each propeller hub 232 and 234 is at or above plane 230, and each propeller hub is entirely above the water surface, when propeller shafts 156 and 158 are parallel to plane 230.
Housing 20 has the noted skeg 194 extending downwardly below torpedo 188. During normal running operation with the boat on plane, the water line is above water intake 192. The water line is at or below the bottom of torpedo 188. Each propeller has a plurality of blades extending radially from the respective hub and defining a propeller diameter across the circumference defined by the outer tips of the blades during rotation. In the preferred embodiment, one-third to one-fifth propeller diameter is below plane 230. In one implementation, the dimension of propeller diameter below plane 230 is about 3 inches, and rotational axis centerline of propeller shafts 156 and 158 is about 5 inches above plane 230 when propeller shafts 156 and 158 are parallel to plane 230.
As above noted, drive 10 is trimmable in and out.
When the drive is trimmed in, the aft end of torpedo 188 moves downwardly. When the drive is trimmed out, the aft end of torpedo 188 moves upwardly. The drive has a given trimmed-in condition, Fig. 5, wherein torpedo 188 extends at an upward angle from the aft end thereof, and the bottom of propeller hubs 232 and 234 define a horizontal line at or above plane 230.
This reduces drag, including in the trimmed-in condition, by keeping both hubs and the torpedo above the water line.
It is recognized that various equivalents, alternatives and modifications are possible within the scope of the appended claims.
Attention is directed to the claims of Application No. 9412860.0 (Publication No. 2279308) from which the present application is divided.

Claims (11)

1. A marine drive for propelling a boat comprising: a housing having a generally horizontal bore and an intersecting generally vertical bore therein, said housing comprising a lower generally horizontal torpedo portion around said horizontal bore; a first inner propeller shaft; a second hollow outer propeller shaft positioned around said first propeller shaft to form a dual propeller shaft assembly, said dual propeller shaft assembly posi tioned in said horizontal bore, said first propeller shaft counter-rotat ing with respect to said second propeller shaft; a generally vertical driveshaft positioned in said vertical bore; a pinion driving gear mounted on the lower end of said vertical driveshaft; a fore driven gear on said first propeller shaft and engaged by said pinion gear to drivingly rotate said first propeller shaft in a first rotational direction;; an aft driven gear on said second propeller shaft and engaged by said pinion gear to drivingly rotate said second propeller shaft in a second rotational direction; a pair of counter-rotating surface operating propellers each mounted to a respective one of said propeller shafts; said torpedo portion being entirely above the plane of the boat bottom when said propeller shafts are parallel to said plane.
2. The invention according to claim 1 wherein the bottom of said torpedo portion is at cr above said plane during high speed operation.
3. The invention according to claim 1 wherein said torpedo portion is entirely above the water surface during high speed operation.
4. The invention according to claim 1 wherein each said propeller is mounted to its respective said propeller shaft by a respective propeller hub, and wherein the bottom of each propeller hub is at or above said plane when said propeller shafts are parallel to said plane.
5. A marine drive for propelling a boat comprising: a housing having a generally horizontal bore and an intersecting generally vertical bore therein, said housing comprising a lower generally horizontal torpedo portion around said horizontal bore; a first inner propeller shaft; a second hollow outer propeller shaft positioned around said first propeller shaft to form a dual propeller shaft assembly, said dual propeller shaft assembly posi tioned in said horizontal bore, said first propeller shaft counter-rotat ing with respect to said second propeller shaft; a generally vertical driveshaft positioned in said vertical bore; a pinion driving gear mounted on the lower end of said vertical driveshaft; a fore driven gear on said first propeller shaft and engaged by said pinion gear to drivingly rotate said first propeller shaft in a first rotational direction;; an aft driven gear on said second propeller shaft and engaged by said pinion gear to drivingly rotate said second propeller shaft in a second rotational direction; a pair of counter-rotating surface operating propellers each mounted to a respective one of said propeller shafts; said housing having a skeg extending downwardly below said torpedo portion, said skeg having a water intake therein, and wherein the water line during normal running operation with the boat on plane is above said water intake.
6. The invention according to claim 5 wherein the water line is at or below the bottom of said torpedo portion.
7. A marine drive for propelling a boat comprising: a housing having a generally horizontal bore and an intersecting generally vertical bore therein, said housing comprising a lower generally horizontal torpedo portion around said horizontal bore; a first inner propeller shaft; a second hollow outer propeller shaft positioned around said first propeller shaft to form a dual propeller shaft assembly, said dual propeller shaft assembly posi tioned in said horizontal bore, said first propeller shaft counter-rotat ing with respect to said second propeller shaft; a generally vertical driveshaft positioned in said vertical bore; a pinion driving gear mounted on the lower end of said vertical driveshaft; a fore driven gear on said first propeller shaft and engaged by said pinion gear to drivingly rotate said first propeller shaft in a first rotational direction;; an aft driven gear on said second propeller shaft and engaged by said pinion gear to drivingly rotate said second propeller shaft in a second rotational direction; a first surface operating propeller mounted by a first propeller hub to said first propeller shaft, and a second surface operating propeller mounted to said second propeller shaft by a second propeller hub, one of said propellers being a right hand rotating propeller, the other of said propellers being a left hand rotating propeller, each propeller having a plurality of blades extending radially from the respective hub and defining a propeller diameter across the circumference defined by the outer tips of the blades during rotation, wherein less than one-third propeller diameter is below the plane of the bottom of the boat.
8. The invention according to claim 7 wherein the dimension of propeller diameter below said plane is about 3 inches.
9. The invention according to claim 7 wherein the rotational axis centerline of said propeller shafts is about 5 inches above said plane when said propeller shafts are parallel to said plane.
10. A marine drive for propelling a boat comprising: a housing having a generally horizontal bore and an intersecting generally vertical bore therein, said housing comprising a lower generally horizontal torpedo portion around said horizontal bore;; a first inner propeller shaft; a second hollow outer propeller shaft positioned around said first propeller shaft to form a dual propeller shaft assembly, said dual propeller shaft assembly posi tioned in said horizontal bore, said first propeller shaft counter-rotat ing with respect to said second propeller shaft; a generally vertical driveshaft positioned in said vertical bore; a pinion driving gear mounted on the lower end of said vertical driveshaft; a fore driven gear on said first propeller shaft and engaged by said pinion gear to drivingly rotate said first propeller shaft in a first rotational direction;; an aft driven gear on said second propeller shaft and engaged by said pinion gear to drivingly rotate said second propeller shaft in a second rotational direction; a first surface operating propeller mounted by a first propeller hub to said first propeller shaft, and a second surface operating propeller mounted to said second propeller shaft by a second propeller hub, one of said propellers being a right hand rotating propeller, the other of said propellers being a left hand rotating propeller, said drive being trimmable in and out, such that when said drive is trimmed in, the aft end of said torpedo portion moves downwardly, and when said drive is trimmed out, the aft end of said torpedo portion moves upwardly, wherein said drive has a given trimmed-in condition wherein said torpedo portion extends at an upward angle from said aft end thereof, and the bottom of said propeller hubs define a horizontal line at or above the plane of the bottom of the boat.
11. A boat having a marine drive as claimed in any one of the preceding claims.
GB9604560A 1993-06-25 1994-06-27 Counter-rotating surfacing marine drive with reduced drag water line Expired - Fee Related GB2295805B (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US8370393A 1993-06-25 1993-06-25
GB9412860A GB2279308B (en) 1993-06-25 1994-06-27 Counter-rotating surfacing marine drive with reduced drag water line

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Publication Number Publication Date
GB9604560D0 GB9604560D0 (en) 1996-05-01
GB2295805A true GB2295805A (en) 1996-06-12
GB2295805B GB2295805B (en) 1997-02-19

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GB9604560A Expired - Fee Related GB2295805B (en) 1993-06-25 1994-06-27 Counter-rotating surfacing marine drive with reduced drag water line

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4871334A (en) * 1988-08-04 1989-10-03 Brunswick Corporation Marine propulsion device with improved exhaust discharge
GB2267264A (en) * 1992-05-27 1993-12-01 Brunswick Corp Counter-rotating surfacing marine drive
GB2267686A (en) * 1992-05-27 1993-12-15 Brunswick Corp Dual propeller marine drive

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4871334A (en) * 1988-08-04 1989-10-03 Brunswick Corporation Marine propulsion device with improved exhaust discharge
GB2267264A (en) * 1992-05-27 1993-12-01 Brunswick Corp Counter-rotating surfacing marine drive
GB2267686A (en) * 1992-05-27 1993-12-15 Brunswick Corp Dual propeller marine drive

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Publication number Publication date
GB9604560D0 (en) 1996-05-01
GB2295805B (en) 1997-02-19

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PCNP Patent ceased through non-payment of renewal fee

Effective date: 19980627