US 6,546,889 B1 · Steering system

Abstract

A steering transmission transmits steering forces that must be transmitted from a steering mechanism, such as a steering wheel or handlebars, to a steered mechanism, such as the rudder of a boat or the steered wheel(s) of an off-road vehicle. The steering transmission includes one and preferably both of a multi-ratio speed changer and a torque gate. The multi-ratio speed changer preferably takes the form of one or more planetary gear sets coupling an input shaft of the transmission to a rotary output of the transmission. The speed changer is shifted by manually operating a shifter to switch between two or more distinct speed change ratios, thereby permitting the operator to select the combination of responsiveness and steering effort desired for the prevailing operating conditions. The torque gate preferably takes the form of a release driver, a locking driver, and a wrapped spring disposed between the release driver and the locking driver. The spring moves relative to a housing or other stationary surface upon the transmission of steering forces to the clutch from the steering mechanism but grips the stationary surface upon the imposition of external backdrive forces on the steering system so as to prevent the transmission of those forces back to the steering wheel and other upstream components of the steering system.

Claims47

Dependent claims

A steering system comprising:

(A) a manually operated steering mechanism;
(B) a steered mechanism;
and
(C) a steering transmission coupling said steering mechanism to said steered mechanism, said steering transmission including
(1) a multi-ratio speed changer having an input element that is coupled to said steering mechanism, an output element that transmits steering forces to said steered mechanism, and a shifter that is movable between at least first and second shifted positions to release a first rotatable gear of said speed changer and arrest a second rotatable gear of said speed changer from rotation and, thereby, vary a speed change ratio of said speed changer between at least first and second distinct speed change ratios;
and
(2) a torque gate coupling said output element of said speed changer to said steered mechanism so as to permit steering forces to be transmitted to said steered mechanism from said speed changer while preventing backdrive forces from being transmitted to said speed changer from said steered mechanism.

4 more elements

A steering system comprising:

(A) a manually operated steering mechanism;
(B) a steered mechanism;
and
(C) a steering transmission coupling said steering mechanism to said steered mechanism, said steering transmission including
(1) a multi-ratio speed changer having an input element that is coupled to said steering mechanism, an output element that transmits steering forces to said steered mechanism, and a shifter that is movable between at least first and second shifted positions to vary a speed change ratio of said speed changer between at least first and second distinct change ratios;
and
(2) a torque gate coupling said output element of said speed changer to said steered mechanism so as to permit steering forces to be transmitted to said steered mechanism from said speed changer while preventing backdrive forces from being transmitted to said speed changer from said steered mechanism, wherein said speed changer includes
an input shaft coupled to said steering mechanism and forming said input element of said speed changer;
a first planetary gear set comprising a first sun gear mounted on said input shaft, a first ring gear, and a first plurality of planet gears disposed between said first ring gear and said first sun gear;
a second planetary gear set comprising a second sun gear mounted on said input shaft, a second ring gear, and a second plurality of planet gears disposed between said second ring gear and said second sun gear, wherein said first and second sun gears are of first and second different diameters;
and
a common carrier for all of said planet gears, said carrier being coupled to an input element of said torque gate and forming at least part of said output element of said speed changer;
wherein
movement of said shifter between said first and second shifted positions selectively arrests one of said first and second ring gears from rotation to select the associated planetary gear set for torque transfer to said driven pin from said input shaft.

11 more elements

A steering system comprising:

(A) a manually operated steering mechanism;
(B) a steered mechanism;
and
(C) a steering transmission coupling said steering mechanism to said steered mechanism, said steering transmission including
(1) a multi-ratio speed changer having an input element that is coupled to said steering mechanism, an output element that transmits steering forces to said steered mechanism, and a shifter that is movable between at least first and second shifted positions to vary a speed change ratio of said speed changer between at least first and second distinct change ratios;
and
(2) a torque gate coupling said output element of said speed changer to said steered mechanism so as to permit steering forces to be transmitted to said steered mechanism from said speed changer while preventing backdrive forces from being transmitted to said speed changer from said steered mechanism, wherein said torque gate comprises
(A) a stationary surface;
(B) a release driver that is coupled to said output element of said speed changer and that is rotatable relative to said stationary surface;
(C) a locking driver that is coupled to said steered mechanism and that is rotatable relative to said stationary surface, wherein said release driver and said locking driver have axially-extending drive surfaces that face one another with a circumferential gap therebetween;
and
(D) a wrapped spring that has at least one coil that is disposed adjacent said stationary surface, wherein said spring, said release driver, said locking driver, and said stationary surface are dimensioned and configured relative to one another such that, (1) upon rotation of said release driver in either direction under torsional forces imposed on said torque gate by said speed changer, said spring rotates relative to said stationary surface so as permit rotation of said release driver and said locking driver, thereby permitting torque transfer to said steered mechanism from said output element of said speed changer, and (2), in the absence of the imposition of an overpowering steering forces on said release driver from said speed changer, and upon rotation of said locking driver in either direction under torsional forces imposed on said torque gate by said steered mechanism, said spring locks against said stationary surface so as prevent said drive surface of said locking driver from driving said release driver to rotate, thereby preventing torque transfer to said speed changer from said steered mechanism.

9 more elements

An outboard motor steering system comprising:

(A) a speed changer including
(1) an input shaft configured for rotational coupling to a steering wheel of a boat,
(2) at least one output element,
(3) at least one planetary gear set including a sun gear mounted on said input shaft, a ring gear, and a plurality of planet gears disposed between said sun gear and said ring gear, and
(4) a shifter that is manually movable into a shifted position thereof to selectively arrest a component of said planetary gear set from rotation to alter a speed change ratio of said speed changer;
and
(B) a torque gate including
(1) a housing having an inner peripheral surface,
(2) a release driver that is located within said housing, that is coupled to said output element of said speed changer, and that is rotatable relative to said housing,
(3) a locking driver that is located within said housing, that is configured for rotational coupling to a steered mechanism for a rudder of the boat, and that is rotatable relative to said housing, wherein said release driver and said locking driver have axially-extending drive surfaces that face one another with a circumferential gap therebetween, and
(4) a wrapped spring that is located within said housing and that is engageable by both said release driver and said locking driver, wherein said spring, said release driver, said locking driver, and said housing are dimensioned and configured relative to one another such that, (1) upon rotation of said release driver in either direction under torsional forces imposed on said torque gate by said speed changer, said spring rotates relative to said housing so as permit said rotation of said release driver and said locking driver, thereby permitting torque transfer to the steered mechanism from said output element of said speed changer, and (2), in the absence of the imposition of overpowering steering forces on one of said release driver from said speed changer, and upon rotation of said locking driver against said spring in either direction under torsional forces imposed on said torque gate by the steered mechanism, said spring locks against said inner peripheral surface of said housing so as prevent said drive surface of said locking driver from driving said release driver to rotate, thereby preventing torque transfer to said speed changer from the steered mechanism.

8 more elements

A torque gate for use in an anti-feedback steering system, comprising

(A) a housing having an inner peripheral surface;
(B) a release driver that is located within said housing, that is configured for coupling to a steering mechanism of the steering system, and that is rotatable relative to said housing, under the imposition of steering forces thereon by the steering mechanism, from a neutral position, through a release position, and into a drive position;
(C) a locking driver that is located within said housing, that is configured for coupling to a steered mechanism of the steering system, and that is rotatable relative to said housing, under the imposition of external forces thereon by the steered mechanism, from a neutral position and to a locking position, wherein said locking driver and said release driver have drive surfaces that overlap one another axially and that are spaced from one another circumferentially;
and
(D) a wrapped spring that is located within said housing and that is engageable by both said release driver and said locking driver, wherein said spring, said release driver, said locking driver, and said housing are dimensioned and configured relative to one another such that, (1) upon rotation of said release driver through said release position and into said drive position in either direction under torsional forces imposed on said torque gate by the steering mechanism, said spring rotates relative to said housing so as permit rotation of said release driver said locking driver, thereby permitting torque transfer to the steered mechanism, and (2), in the absence of the imposition of overpowering steering forces on said release driver from the steering mechanism, and upon rotation of said locking driver to said locking position thereof in either direction under torsional forces imposed on said torque gate by the steered mechanism, said locking driver engages said spring so as to cause said spring to lock against said inner peripheral surface of said housing so as to prevent said locking driver from driving said release driver to rotate, thereby preventing torque transfer to the steering mechanism from the steered mechanism.

2 more elements

A method comprising:

(A) imposing a steering force on a steering mechanism;
(B) transmitting said steering force to a rotary speed changer at a first rotational velocity;
(C) transmitting said steering force from said speed changer to a torque gate at a second rotational velocity, a ratio between said first and second rotational velocities being determined by a speed change ratio of said speed changer;
(D) transmitting said steering force to a steered mechanism from said torque gate;
(E) shifting said speed changer to alter said speed change ratio, the shifting step comprising moving a shifter 1) from a first shifted position arresting a first rotatable gear of said speed changer from rotation and permitting a second rotatable gear of said speed changer to rotate 2) to a second shifted position arresting said second gear of said speed changer from rotation and permitting said first gear of said speed changer to rotate;
and
(F) preventing forces imposed on or by said steering mechanism from being transmitted back to said speed changer through said torque gate.

4 more elements

Dependencies are inferred from the claim text.

Steering system

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Steering system

Life of this patent

Abstract

Claims47