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US4378748A Expired / Lapsed US ⏱️ 0.0 years remaining

Sailboat keel apparatus

Assignee: Individual
•
Filing: 1982-01-18
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Granted: 1983-04-05
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Expires: 2002-01-18
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Abstract

Abstract A sailboat carries a pair of opposed keel sections which are angularly positionable about a common hinge axis, either as a keel unit or individually, by means of compressed air biased hydraulic actuators connected via shock absorbers to the keel sections. An additional hydraulic actuator, adjusts the angle of elevation of the hinge axis, enabling the keel unit or sections, when inclined, to provide hydrodynamic lift. The keel sections, which are hollow and contain radially flowable ballast, are configured, when oppositely horizontally positioned to receive the axles of removable wheels, enabling the boat to be self-trailered.

Inventors

  • 👤 Joel Kurtz

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 16:29
CPC Classifications
B; B63; B63C; B63C13/00; B63B; B63B1/00; B63B1/16; B63B1/24; B63B1/28; B63B41/00; B63B35/00; B63B2035/009; B63B39/00; B63B39/06; B63B2039/065

Claims Analysis

Total Claims: 31
Claim 1
Independent Claim 105 words
In a boat, attitude control apparatus comprising a keel axis mounted for elevational angulation at a medial point on the underside of said boat; first positioning means coupled to said keel axis for adjusting the elevation angle between said keel axis and the longitudinal axis of said boat and for maintaining said keel axis in fixed orientation, after adjustment, relative to the longitudinal axis of said boat; a keel means pendant from said keel axis for angulation about said fixedly oriented keel axis; and second positioning means coupled to said keel means for adjusting the angular position of said keel means about said keel axis.
Claim 2
Dependent Claim 105 words
In a boat, attitude control apparatus comprising a keel axis mounted for elevational angulation at a medial point on the underside of said boat; first positioning means coupled to said keel axis for adjusting the elevation angle between said keel axis and the longitudinal axis of said boat and for maintaining said keel axis in fixed orientation, after adjustment, relative to the longitudinal axis of said boat; a keel means pendant from said keel axis for angulation about said fixedly oriented keel axis; and second positioning means coupled to said keel means for adjusting the angular position of said keel means about said keel axis.
Claim 3
Dependent Claim 60 words
The apparatus of claim 1 wherein said keel means comprises port and starboard facing angularly opposed keel sections each independently angularly positionable about said keel axis; and wherein said second positioning means includes a port keel section positioning actuator coupled to said port facing keel section and a starboard keel section positioning actuator coupled to said starboard facing keel section.
Claim 4
Dependent Claim 151 words
The apparatus of claim 2, wherein, said port and starboard keel section positioning actuators respectively comprise opposed port and starboard hydraulic slave cylinders; said apparatus further comprising port and starboard hydraulic master cylinders within said boat respectively hydraulically coupled to said port and starboard slave cylinders, each of said master cylinders having a piston, first control means coupled between the pistons of said port and starboard master cylinders for simultaneously increasing the hydraulic volume of a selected one of said master cylinders and decreasing the hydraulic volume of the other of said master cylinders for selectively causing said port and starboard facing keel sections to rotate angularly in the same direction about said keel axis and second control means comprising hydraulic pump means coupled hydraulically to each of said master cylinders for selectively causing said port and starboard facing keel sections to rotate angularly in opposite directions about said keel axis.
Claim 5
Dependent Claim 130 words
The apparatus of claim 2, wherein said port and starboard keel section positioning actuators comprise cylinders for receiving opposed hydraulic and air pressures, said cylinders being directed for angularly downwardly rotating said keel sections in response to an excess of hydraulic pressure with respect to air pressure and angularly upwardly rotating said keel sections in response to an excess of air pressure with respect to hydraulic pressure; control means within said boat coupled for applying selected hydraulic pressures to said cylinders; and air pressure storage tank means within said boat coupled for applying air pressure to said cylinders; whereby said keel sections may be raised in opposite directions by air pressure from said storage tank means upon the application of no or relatively small hydraulic pressures from said control means.
Claim 6
Dependent Claim 34 words
The apparatus of claim 2, wherein the end of each keel section is configured to carry the axle of a removeable tractive wheel to enable the boat to be supported and moved on land.
Claim 7
Dependent Claim 81 words
The apparatus of claim 1, wherein said keel means is hollow substantially throughout its radial extent and further comprising flowable ballast partially filling said keel means, wherein when said keel means is in a raised position with the radial extremity of said keel means above said keel axis, said ballast flows radially inward, in response to gravitational forces, toward said keel axis for reducing the forces required by said second positioning means for maintaining said keel means in said raised position.
Claim 8
Dependent Claim 87 words
The apparatus of claim 2, wherein each of said port and starboard facing keel sections is hollow substantially throughout its radial extent, and further comprising flowable ballast partially filling each said keel section, wherein when a keel section is in a raised position with the radial extremity of said keel section above said keel axis, said ballast flows radially inward, in response to gravitational forces, toward said keel axis for reducing the force required by the associated actuator for maintaining the keel section in said raised position.
Claim 9
Dependent Claim 55 words
The apparatus of claim 1, wherein said keel means has port and starboard facing sides and wherein said second positioning means comprises a port keel means positioning actuator coupled to the port facing side of said keel means and a starboard keel means positioning actuator coupled to the starboard facing side of said keel means.
Claim 10
Dependent Claim 104 words
The apparatus of claim 8, wherein said port and starboard keel means positioning actuators respectively comprise opposed port and starboard hydraulic slave cylinders, said apparatus further comprising port and starboard hydraulic master cylinders within said boat respectively hydraulically coupled to said port and starboard slave cylinders, each of said master cylinders having a piston, mechanical control means coupled between the pistons of said port and starboard master cylinders for simultaneously increasing the hydraulic volume of a selected one of said master cylinders and decreasing the hydraulic volume of the other of said master cylinders for rotating said keel means angularly in a selected direction.
Claim 11
Dependent Claim 105 words
In a boat, combined attitude control and trailering means comprising: a generally longitudinally directed keel axis mounted at a medial point on the underside of said boat, port and starboard facing angularly opposed keel sections mounted for independent angular positioning about said keel axis; port and starboard keel section positioning actuators respectively coupled to said port and starboard facing keel sections for independently angularly positioning said keel sections about said keel axis for attitude control of said boat; the end of each keel section being configured to engage the axle of removeable tractive wheel to enable the boat to be supported and moved on land.
Claim 12
Dependent Claim 105 words
In a boat, combined attitude control and trailering means comprising: a generally longitudinally directed keel axis mounted at a medial point on the underside of said boat, port and starboard facing angularly opposed keel sections mounted for independent angular positioning about said keel axis; port and starboard keel section positioning actuators respectively coupled to said port and starboard facing keel sections for independently angularly positioning said keel sections about said keel axis for attitude control of said boat; the end of each keel section being configured to engage the axle of removeable tractive wheel to enable the boat to be supported and moved on land.
Claim 13
Dependent Claim 151 words
The apparatus of claim 10, wherein said port and starboard keel section positioning actuators respectively comprise opposed port and starboard hydraulic slave cylinders; said apparatus further comprising port and starboard hydraulic master cylinders within said boat respectively hydraulically coupled to said port and starboard slave cylinders each of said master cylinders having a piston, first control means coupled between the pistons of said port and starboard master cylinders for simultaneously increasing the hydraulic volume of a selected one of said master cylinders and decreasing the hydraulic volume of the other of said master cylinders for selectively causing said port and starboard facing keel sections to rotate angularly in the same direction about said keel axis, and second control means comprising hydraulic pump means coupled hydraulically to each of said master cylinders for selectively causing said port and starboard facing keel sections to rotate angularly in opposite directions about said keel axis.
Claim 14
Dependent Claim 121 words
The apparatus of claim 10, wherein said port and starboard keel section positioning actuators comprise cylinders being directed for angularly downwardly rotating said keel sections in response to an excess of hydraulic pressure with respect to air pressure and angularly upwardly rotating said keel sections in response to an excess of air pressure with respect to hydraulic pressure; control means within said boat coupled for applying selected hydraulic pressures to said cylinders; and air pressure storage tank means within said boat coupled for applying air pressure to said cylinders; whereby said keel sections may be raised in opposite directions by air pressure from said storage tank means upon the application of no or relatively small hydraulic pressures from said control means.
Claim 15
Dependent Claim 82 words
The apparatus of claim 10, wherein each of said port and starboard facing keel sections is hollow substantially throughout its radial extent, and further comprising flowable ballast partially filling each said keel section, wherein when a keel section is in a raised position with the radial extremity of said keel section above said keel axis, said ballast flows radially inward toward said keel axis for reducing the force required by the associated actuator for maintaining the keel section in said raised position.
Claim 16
Dependent Claim 168 words
In a boat, attitude control apparatus comprising: a generally longitudinally directed keel axis mounted at a medial point on the underside of said boat, a keel means pendant from said keel axis for angulation about said keel axis; said keel means having port and starboard facing sides, port and starboard facing shock absorber means comprising port and starboard facing tracks respectively in the port and starboard facing sides of said keel means, said tracks being directed radially from said keel axis, and port and starboard facing sliders captured respectively in said port and starboard facing tracks, said tracks and sliders being configured to cooperate with ambient water about said keel means, to produce viscous frictional forces opposing movement of said sliders along said tracks; arising from ambient water displaced by the movement of said sliders being forced through relatively narrow openings in said tracks; and port and starboard actuators respectively connected to said port and starboard facing sliders for positioning said keel means angularly about said keel axis.
Claim 17
Dependent Claim 168 words
In a boat, attitude control apparatus comprising: a generally longitudinally directed keel axis mounted at a medial point on the underside of said boat, a keel means pendant from said keel axis for angulation about said keel axis; said keel means having port and starboard facing sides, port and starboard facing shock absorber means comprising port and starboard facing tracks respectively in the port and starboard facing sides of said keel means, said tracks being directed radially from said keel axis, and port and starboard facing sliders captured respectively in said port and starboard facing tracks, said tracks and sliders being configured to cooperate with ambient water about said keel means, to produce viscous frictional forces opposing movement of said sliders along said tracks; arising from ambient water displaced by the movement of said sliders being forced through relatively narrow openings in said tracks; and port and starboard actuators respectively connected to said port and starboard facing sliders for positioning said keel means angularly about said keel axis.
Claim 18
Dependent Claim 82 words
The apparatus of claim 14, wherein said keel means is hollow substantially throughout its radial extent and further comprising flowable ballast partially filling said keel means, wherein when said keel means is in a raised position with the radial extremity of said keel means above said keel axis, said ballast flows radially inward, in response to gravitational forces, toward said keel axis for reducing the force required by said port and starboard actuators for maintaining said keel means in said raised position.
Claim 19
Dependent Claim 45 words
The apparatus of claim 15, wherein said keel means comprises port and starboard facing angularly opposed keel sections each independently angularly positionable about said keel axis, said port and starboard facing shock absorber means being respectively carried by said port and starboard facing keel sections.
Claim 20
Dependent Claim 34 words
The apparatus of claim 16, wherein the end of each keel section is configured to carry the axle of a removeable tractive wheel to enable the boat to be supported and moved on land.
Claim 21
Dependent Claim 148 words
The apparatus of claim 16, wherein said port and starboard actuators respectively comprise opposed port and starboard hydraulic slave cylinders; said apparatus further comprising port and starboard hydraulic master cylinders within said boat respectively hydraulically coupled to said port and starboard slave cylinders each of said master cylinders having a piston, first control means coupled between the pistons of said port and starboard master cylinders for simultaneously increasing the hydraulic volume of a selected one of said master cylinders and decreasing the hydraulic volume of the other of said master cylinders for selectively causing said port and starboard facing keel sections to rotate angularly in the same direction about said keel axis, and second control means comprising hydraulic pump means coupled hydraulically to each of said master cylinders for selectively causing said port and starboard facing keel sections to rotate angularly in opposite directions about said keel axis.
Claim 22
Dependent Claim 127 words
The apparatus of claim 16 wherein, said port and starboard actuators comprise cylinders for receiving opposed hydraulic and air pressures, said cylinders being directed for angularly downwardly rotating said keel sections in response to an excess of hydraulic pressure with respect to air pressure and angularly upwardly rotating said keel sections in response to an excess of air pressure with respect to hydraulic pressure; control means within said boat coupled for applying selected hydraulic pressures to said cylinders; and air pressure storage tank means within said boat coupled for applying air pressure to said cylinders; whereby said keel sections may be raised in opposite directions by air pressure from said storage tank means upon the application of no or relatively small hydraulic pressures from said control means.
Claim 23
Dependent Claim 208 words
In a boat, attitude control apparatus comprising: a generally longitudinally directed keel axis mounted at a medial point on the underside of said boat; a keel means, comprising angularly opposed independently positionable port and starboard keel sections, pendant from said keel axis for angulation about said keel axis; port and starboard keel section positioning actuators respectively coupled to said port and starboard keel sections for independently angularly positioning said port and starboard keel sections about said keel axis, said port and starboard keel sections positioning actuators respectively comprising opposed port and starboard hydraulic slave cylinders; said apparatus further comprising port and starboard hydraulic master cylinders within said boat respectively hydraulically coupled to said port and starboard slave cylinders, each of said master cylinders having a piston, and control means coupled between the pistons of said port and starboard master cylinders for selectively simultaneously increasing the hydraulic volume of a selected one of said master cylinders and decreasing the hydraulic volume of the other of said master cylinders, for selectively causing said port and starboard keel sections to rotate in the same direction, and hydraulic means coupled hydraulically to each of said master cylinders for selectively causing said port and starboard keel sections to rotate angularly in opposite directions.
Claim 24
Dependent Claim 208 words
In a boat, attitude control apparatus comprising: a generally longitudinally directed keel axis mounted at a medial point on the underside of said boat; a keel means, comprising angularly opposed independently positionable port and starboard keel sections, pendant from said keel axis for angulation about said keel axis; port and starboard keel section positioning actuators respectively coupled to said port and starboard keel sections for independently angularly positioning said port and starboard keel sections about said keel axis, said port and starboard keel sections positioning actuators respectively comprising opposed port and starboard hydraulic slave cylinders; said apparatus further comprising port and starboard hydraulic master cylinders within said boat respectively hydraulically coupled to said port and starboard slave cylinders, each of said master cylinders having a piston, and control means coupled between the pistons of said port and starboard master cylinders for selectively simultaneously increasing the hydraulic volume of a selected one of said master cylinders and decreasing the hydraulic volume of the other of said master cylinders, for selectively causing said port and starboard keel sections to rotate in the same direction, and hydraulic means coupled hydraulically to each of said master cylinders for selectively causing said port and starboard keel sections to rotate angularly in opposite directions.
Claim 25
Dependent Claim 143 words
The apparatus of claim 20 wherein, said port and starboard slave cylinders are configured for receiving opposed hydraulic and air pressures, said slave cylinders being directed for angularly downwardly rotating said keel sections in response to an excess of hydraulic pressure with respect to air pressure and angularly upwardly rotating said keel sections in response to an excess of air pressure with respect to hydraulic pressure, said hydraulic pressures being supplied to said port and starboard slave cylinders respectively by said port and starboard master cylinders; and an air pressure storage tank means within said boat coupled for applying air pressure to said slave cylinders, whereby said keel sections may be raised in opposite directions by air pressure from said storage tank means in response to the supply to said slave cylinders of no or relatively small hydraulic pressures from said master cylinders.
Claim 26
Dependent Claim 34 words
The apparatus of claim 20, wherein the end of each keel section is configured to carry the axle of a removable tractive wheel to enable the boat to be supported and moved on land.
Claim 27
Dependent Claim 83 words
The apparatus of claim 20, wherein each of said port and starboard facing keel sections is hollow substantially throughout its radial extent, and further comprising flowable ballast partially filling each said keel section, wherein when a keel section is in a raised position with the radial extremity of said keel section above said keel axis, said ballast flows radially inward toward said keel axis for reducing the force required by the associated slave cylinder for maintaining the keel section in said raised position.
Claim 28
Dependent Claim 191 words
In a boat, attitude control apparatus comprising: a generally longitudinally directed keel axis mounted at a medial point on the underside of said boat, port and starboard facing angularly opposed keel sections mounted for independent angular positioning about said keel axis; port and starboard keel section positioning actuators respectively coupled to said port and starboard facing keel sections for angularly positioning said keel sections about said keel axis, said port and starboard keel section positioning actuators comprising cylinders for receiving opposed hydraulic and air pressures, said cylinders being directed for angularly downwardly rotating said keel sections in response to an excess of hydraulic pressure with respect to air pressure and angularly upwardly rotating said keel sections in response to an excess of air pressure with respect to hydraulic pressure; control means within said boat coupled for applying selected hydraulic pressures to said cylinders and air pressure storage tank means within said boat coupled for applying air pressure to said cylinders; whereby said keel sections may be raised in opposite directions by air pressure from said storage tanks upon the application of no or relatively small hydraulic pressure from said control means.
Claim 29
Dependent Claim 191 words
In a boat, attitude control apparatus comprising: a generally longitudinally directed keel axis mounted at a medial point on the underside of said boat, port and starboard facing angularly opposed keel sections mounted for independent angular positioning about said keel axis; port and starboard keel section positioning actuators respectively coupled to said port and starboard facing keel sections for angularly positioning said keel sections about said keel axis, said port and starboard keel section positioning actuators comprising cylinders for receiving opposed hydraulic and air pressures, said cylinders being directed for angularly downwardly rotating said keel sections in response to an excess of hydraulic pressure with respect to air pressure and angularly upwardly rotating said keel sections in response to an excess of air pressure with respect to hydraulic pressure; control means within said boat coupled for applying selected hydraulic pressures to said cylinders and air pressure storage tank means within said boat coupled for applying air pressure to said cylinders; whereby said keel sections may be raised in opposite directions by air pressure from said storage tanks upon the application of no or relatively small hydraulic pressure from said control means.
Claim 30
Dependent Claim 34 words
The apparatus of claim 24 wherein, the end of each keel section is configured to carry the axle of a removable tractive wheel to enable the boat to be supported and moved on land.
Claim 31
Dependent Claim 82 words
The apparatus of claim 24 wherein, each of said port and starboard facing keel sections is hollow substantially throughout its radial extent, and further comprising flowable ballast partially filling each said keel section, wherein when a keel section is in a raised position with the radial extremity of said keel section above said keel axis, said ballast flows radially inward toward said keel axis for reducing the force required by the associated actuator for maintaining the keel section in said raised position.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1986-04-04 1986-10-04 1987-04-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1990-04-04 1990-10-04 1991-04-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1994-04-04 1994-10-04 1995-04-05 $7700.00 Window Closed / Lapsed

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