Spring-assisted jack plate for outboard motor

A jack plate includes a mounting assembly having first and second spacing brackets connected by a transom plate adapted for mounting to the transom of a boat, each of the spacing brackets having inwardly facing channels at rearward sides of the spacing brackets. The jack plate further includes a motor lift including a lift plate extending between a first bearing and a second bearing, the channels adapted to conformingly receive the first and second bearings. An actuator is provided to raise and lower the lift plate relative to the transom plate. At least one spring is operably coupled between the mounting assembly and the motor lift, the spring unloading the lift plate to reduce load on the actuator. The spring is optionally a compression gas spring.

FIELD OF THE DISCLOSURE

The present invention relates to a mechanism for mounting outboard motors onto boats. More specifically, the present invention relates to a jack plate for vertically adjusting the trim and/or height of an outboard motor.

BACKGROUND OF THE DISCLOSURE

During operation of a boat powered by an outboard motor, it is often desirable to raise or lower the motor. For example, when operating a boat in shallow water or removing a boat from the water with a submersible boat trailer, it is often necessary to raise the motor so that the propeller and rudder are not damaged by the bottom of the body of water. In other instances, it may be desirable to raise the motor while operating the boat at high speeds to reduce the amount of drag created by the presence of the motor in the water.

Adjusting the trim or height of an outboard motor can be accomplished by manipulating a set of controls operably connected to a jack plate. Although meanings of the term jack plate can vary, for purposes of this application, jack plate refers to the interfacing apparatus between a boat and an accompanying outboard motor. Generally, a component of the jack plate is fixedly mounted to the transom of the boat, while another component is mounted to the outboard motor. By operating an actuator attached to the two components, the motor can be raised or lowered in relation to the transom. A number of different types of lift actuators have been incorporated into jack plates, such as, for example, hydraulic, electric, electro-mechanical, or strictly manually operated actuators.

Jack plates can accomplish raising or lowering the propeller of an outboard motor by pivoting the motor about a selected point, such as at or near the top of the transom. Pivoting an outboard motor to raise the motor, however, has several drawbacks. As the motor pivots, the angle at which the propeller displaces water changes, resulting in a decrease in the propulsive efficiency of the motor.

Because of the drawbacks associated with tilting outboard motors, jack plates have been developed that can raise or lower the entire outboard motor in a substantially vertical direction. For example, U.S. Pat. Nos. 8,627,779 and 8,267,025, both of which are incorporated herein by reference, show an actuator-powered jack plate having a transom plate mountable to a boat transom and a motor lift plate movable substantially vertically with respect to the transom plate. The larger the motor mounted to the motor lift plate, the greater the load that must be accommodated by the actuator to raise and lower the motor with respect to the boat. Accordingly, more powerful and/or more durable actuators have been called for to maintain performance over time with larger motors.

SUMMARY

In an embodiment, a jack plate comprises a mounting assembly comprising a first spacing bracket, a second spacing bracket, and a transom plate extending between the first spacing bracket and the second spacing bracket. The first spacing bracket defines a first channel and the second spacing bracket defines a second channel with the first channel and the second channel opening toward one another. The jack plate further includes a lift plate assembly that is movable relative to the mounting plate. The lift plate assembly comprises a first slider slidingly received in the first channel, a second slider slidingly received in the second channel, and a lift plate extending between the first slider and the second slider. The jack plate comprises an actuator operably coupled between the mounting assembly and the lift plate assembly for moving the lift plate assembly relative to the mounting assembly. The jack plate also includes a spring operably coupled between the mounting assembly and the lift plate assembly, the spring applying a biasing force between the lift plate assembly and the mounting assembly. The spring comprises a spring housing having a spring wall defining in a cylinder bore and a piston disposed inside the cylinder bore. The piston separates a first part of the cylinder bore from a second part of the cylinder bore. A pressurized gas is disposed in the first part of the cylinder bore. The second part of the cylinder bore is in fluid communication with the outside atmosphere A. The outside atmosphere A has an atmospheric pressure and the pressurized gas has a pressure that is greater than the atmospheric pressure so that there is a pressure differential across the piston. The spring housing also has an end portion comprising the female mounting thread that is co-axial with the cylinder bore. The actuator includes an actuator casing that defines a socket dimensioned to receive the end portion of the cylinder housing. In an embodiment, the end portion of the cylinder housing is disposed n the socket defined by the actuator casing. The end portion of the cylinder housing is fixed to the actuator casing by a mounting screw. The mounting screw disposed in threaded engagement with the female mounting thread.

In an embodiment, the piston further comprises a piston rod having a first end portion fixed to the piston and a second end portion fixed to a clevis. In this embodiment, the clevis is pivotally coupled to the transom plate by a lower pin extending through a clevis hole in the clevis and corresponding holes defined by a lower mounting bracket.

In an embodiment, the actuator casing is pivotally coupled to the lift plate by an upper pin extending through an upper mounting hole defined by the actuator rod and corresponding holes defined by an upper mounting bracket. In this embodiment, the upper mounting bracket is fixed to the lift plate.

In an embodiment, the actuator further comprises an actuator rod defining an lower mounting hole, the actuator rod being pivotally coupled to the transom plate by a lower pin extending through the lower mounting hole and corresponding holes defined by a lower mounting bracket. In this embodiment, the lower mounting bracket is fixed to the transom plate.

In an embodiment, the jack plate further includes a male washer and a female washer disposed inside the socket defined by the actuator housing with the mounting screw extending through the male washer and the female washer. The male washer and a female washer are disposed between an upward facing surface of the end portion of the spring housing and a downward facing surface of the actuator casing. The female washer comprises a female surface defining a cavity. The male washer comprises a male surface. The male surface of the male washer is received in the cavity defined by the female surface of the female washer. In an embodiment, the male surface of the male washer is seated against and in contact with the female surface of the female washer. In an embodiment the male surface of the male washer comprises at least one convex surface. In an embodiment the female surface of the female washer comprises a concave surface. In an embodiment the cavity defined by the female surface of the female washer has a shape corresponding to a cone.

In an embodiment, the spring of the jack plate is biased to expand in length and the spring is allowed to extend in length while the actuator is activated to raise the lift plate.

In an embodiment, the spring is biased to expand in length and the actuator prevents the spring from expanding in length when the actuator is not activated.

In an embodiment, the spring is biased to expand in length and the spring is forced to contract in length while the actuator is activated to lower the lift plate.

In embodiment, a boat comprises a hull having a transom, an outboard motor, and a jack plate disposed intermediate the hull and the outboard motor. In an embodiment, the jack plate includes a transom plate that is fixed to the transom of the hull. The outboard motor is fixed to a lift plate of the jack plate.

In an embodiment, a jack plate comprises a mounting assembly comprising a first spacing bracket, a second spacing bracket, and a transom plate extending between the first spacing bracket and the second spacing bracket. The first spacing bracket defines a first channel and the second spacing bracket defines a second channel with the first channel and the second channel opening toward one another. A lift plate assembly of the jack plate comprises a first slider slidingly received in the first channel and a second slider slidingly received in the second channel. A lift plate of the lift plate assembly extends between the first slider and the second slider. An actuator of the jack plate is operably coupled between the mounting assembly and the lift plate assembly for moving the lift plate assembly relative to the mounting assembly. A spring of the jack plate is operably coupled between the mounting assembly and the lift plate assembly, the spring applying a biasing force between the lift plate assembly and the mounting assembly.

In an embodiment, a jack plate includes a mounting assembly having first and second spacing brackets connected by a transom plate adapted for mounting to the transom of a boat, each of the spacing brackets having inwardly facing channels at rearward sides of the spacing brackets. The jack plate further includes a motor lift including a lift plate extending between a first bearing and a second bearing, the channels adapted to conformingly receive the first and second bearings. An actuator is provided to raise and lower the lift plate relative to the transom plate. At least one spring is operably coupled between the mounting assembly and the motor lift, the spring unloading the lift plate to reduce load on the actuator. The spring is optionally a compression gas spring.

DETAILED DESCRIPTION

Referring toFIG. 1, jack plate100comprises motor lift102and jack plate mounting assembly104. Jack plate100generally also includes actuator106. In one embodiment, actuator106is an electro-mechanical ball screw actuator driven by an associated motor and controlled by control switch. In other embodiments, actuator106is an electrical, a mechanical or other type of actuator106. Manual actuation is also contemplated, according to embodiments of the invention.

Motor lift102comprises lift plate110and bearings112,114, as depicted inFIGS. 1-3. Motor lift102generally also includes actuator mount116. In an embodiment, actuator mount116is formed from two actuator brackets118,120. In alternative embodiments, actuator mount116is formed from a single actuator bracket or from actuator mount116having several actuator brackets118,120and/or additional components. Lift plate110includes motor-mounting apertures134and actuator mounting apertures135.

Jack plate mounting assembly104also includes spacing brackets,160,162, transom plate164, and actuator mount165. Each spacing bracket160or162has jack plate rail166. Transom plate164is adapted to mount to the transom or other structure associated with a boat. Actuator mount165supports the opposite side of actuator106relative to actuator mount116. Actuator mount165is optionally formed from two actuator brackets230,232, as depicted inFIG. 2. In alternative embodiments, actuator mount165is formed from a single actuator bracket or from an actuator mount assembly having several actuator brackets and/or additional components.

Motor lift102is positioned within jack plate mounting assembly102by inserting bearings112,114into jack plate rails166. In an embodiment, a lubricant is also added to bearings112,114or jack plate rails166. By inserting bearings112,114into jack plate rails166, motor lift102is pressure fit within spacing brackets160,162of jack plate mounting assembly104. Actuator106is generally attached to motor lift102and jack plate mounting assembly104.

Actuator106is attached to actuator mount116of motor lift and actuator mount165of jack plate mounting assembly104. Actuator106is operably connected to a power source (not shown). As described earlier, in one embodiment, the power source provides electrical power. In other embodiments, the power source provides hydraulic power or other types of power.

Embodiments of the invention include one or more springs to compensate for the weight of outboard motor60. Larger, heavier motors can cause excessive load on actuator106, requiring actuator106to be larger, rated for larger loads, heavier, more durable, and/or otherwise suited for the extra weight associated with large motors. Such measures can increase the cost, maintenance, power requirements, rated wiring or piping, and other considerations associated with actuator106. Using springs according to embodiments of the invention to compensate for the weight of motor60eliminates a number of these requirements and provides other advantages.

According to one embodiment, spring300is provided to compensate for the weight of motor60and motor lift plate110. For simplicity of illustration, a single spring300is illustrated on the left-hand side of jack plate100as viewed inFIGS. 1 and 2, but it should be appreciated that embodiments of the invention optionally include a second, identical spring300, in a corresponding position on the right-hand side of jack plate100as viewed in those figures. Spring300is optionally a gas spring that includes piston305received in cylinder310in a telescoping arrangement. Gas spring300is filled with nitrogen or other inert gas, and is constructed as a compression gas spring to exert an outwardly directed force in the longitudinal direction upon compression, as will be appreciated by those of ordinary skill in the art upon reading this disclosure. Any number of different types of gas springs are contemplated according to embodiments of the invention, including off-the-shelf gas springs readily available in the marketplace. The level of force necessary to compress spring300, and the amount of outward force exerted by spring300upon compression, is optionally adjustable.

To mount each gas spring300, motor lift plate110includes one or more flanges315, disposed on opposite sides of lift plate110. Flanges315include mounting apertures320for receiving suitable mounting hardware325for the upper end of gas spring300. Although cylinder310is at the upper portion of spring300as viewed in the figures, it will be appreciated upon reading this disclosure that piston305can be placed as the upper end of spring300instead. The opposite end of each spring300is attached to respective apertures330disposed, for example, on the inner sides of spacing brackets160,162. Suitable mounting hardware335connects each spring300to apertures330.

Those of ordinary skill in the art will appreciate, upon reading this disclosure, that the upper end of spring300alternatively can be attached to the major plane of lift plate110(the plane perpendicular to flanges315). Suitable apertures can be provided in lift plate110to receive suitable mounting hardware for spring300. It will also be appreciated that the lower end of spring300can be mounted to other portions of jack plate mounting assembly104, including transom plate164, if desired.

To install jack plate100, transom plate164is attached to the transom of boat50and lift plate110is attached to outboard motor60, as depicted inFIGS. 4-5. Fastening members are inserted through transom-mounting apertures of spacing brackets160,162and transom plate164. Fastening members are also inserted through motor-mounting apertures134of lift plate110. Compression gas spring300or other type of spring is installed under compression loading between motor lift102and jack plate mounting assembly104, e.g. operably coupled between motor lift plate110and transom plate164or spacing brackets160,162. Other features and details related to and in combination with embodiments of the present invention are described in U.S. Pat. Nos. 8,627,779 and 8,267,025, incorporated by reference above.

In operation, jack plate100raises and lowers the depth of motor60within the water through the manipulation of controls operably connected to actuator106, such as, for example, to adjust the trim of boat50within a body of water. Jack plate100is generally mounted to the transom of boat50. Since jack plate mounting assembly104is fixedly attached to boat50, movement of actuator106causes a corresponding movement of motor lift102. Therefore, as actuator106is extended, motor lift102rises in relation to jack plate mounting assembly104, causing motor60to be raised toward the surface of the water. Similarly, as actuator106is retracted, motor lift102descends in relation to jack plate mounting assembly104, causing motor60to be lowered further below the surface of the water. Spring300reduces the amount of force that must be applied by actuator106to effect the raising and lowering of motor60. Embodiments of the invention thus provide spring force to unload the jack plate and allow for easier raising and lowering of outboard motors relative to associated boats or other watercraft. Embodiments of the invention provide for use of a less powerful, smaller, lighter weight, and/or less expensive actuator, or provide easier manual operation. Longevity of the actuator is enhanced, reducing the possibility of costly repair or replacement, untimely breakdowns, or other disadvantages.FIG. 4schematically illustrates spring300as a compression spring, as indicated by outwardly directed force arrows350. The upper end of spring300is attached or otherwise operably coupled with an upper portion of motor lift plate110at aperture or other feature320thereof, and the lower end of spring300is attached at aperture or other feature330of jack plate mounting assembly104. Embodiments of the invention also contemplate that spring300is an extension spring, which extends to create load instead of compressing to create load.FIG. 5schematically illustrates spring300as an extension spring, as indicated by inwardly directed force arrows355. In this example, the lower end of spring300is attached at aperture360(see alsoFIG. 3) of motor lift plate110, and the upper end of spring300is attached at aperture365to an upper portion of jack plate mounting assembly104. Extension gas spring300or other type of spring is installed under tension loading between motor lift102and jack plate mounting assembly104, e.g. operably coupled between motor lift plate110and transom plate164or spacing brackets160,162.

Referring toFIGS. 6 through 12, in an embodiment, a jack plate500comprises a mounting assembly502comprising a first spacing bracket504, a second spacing bracket506, and a transom plate508extending between the first spacing bracket504and the second spacing bracket506. The first spacing bracket504defines a first channel520and the second spacing bracket506defines a second channel522with the first channel520and the second channel522opening toward one another. The jack plate500further includes a lift plate assembly524that is movable relative to the transom plate508. The lift plate assembly524comprises a first slider528slidingly received in the first channel520, a second slider530slidingly received in the second channel522, and a lift plate526extending between the first slider528and the second slider530. An actuator532of the jack plate500is operably coupled between the mounting assembly502and the lift plate assembly524for moving the lift plate assembly524relative to the mounting assembly502. A spring564of the jack plate500is operably coupled between the mounting assembly502and the lift plate assembly524. The spring564applies a biasing force between the lift plate assembly524and the mounting assembly502. The spring564comprises a spring housing566having a housing wall572defining in a cylinder bore574and a piston576disposed inside the cylinder bore574. The piston576separates a first part578of the cylinder bore574from a second part580of the cylinder bore574. A pressurized gas582is disposed in the first part578of the cylinder bore574. A pattern of dots is used to illustrate pressurized gas582in the figures. The second part580of the cylinder bore574is in fluid communication with the outside atmosphere A. The outside atmosphere A has an atmospheric pressure and the pressurized gas582has a pressure that is greater than the atmospheric pressure so that there is a pressure differential across the piston576. The spring housing566also has an end portion568comprising the female mounting thread570that is co-axial with the cylinder bore574. The actuator532includes an actuator casing536that defines a socket538dimensioned to receive the end portion568of the spring housing566. In the embodiment shown in the figures, the end portion568of the spring housing566is disposed in the socket538defined by the actuator casing536. In the embodiment shown in the figures, the end portion568of the spring housing566is fixed to the actuator casing536by a mounting screw552. The mounting screw552is disposed in threaded engagement with the female mounting thread570.

Referring toFIGS. 6-10, the piston576further comprises a piston rod584having a first end portion fixed to the piston576and a second end portion fixed to a clevis586. In this embodiment, the clevis586is pivotally coupled to the transom plate508by a lower pin546extending through a clevis hole588defined by the clevis and corresponding holes defined by a lower mounting bracket550.

Referring toFIGS. 6-10the actuator casing536is pivotally coupled to the lift plate526by an upper pin544extending through an upper mounting hole540defined by the actuator rod534and corresponding holes defined by an upper mounting bracket548. In this embodiment, the upper mounting bracket548is fixed to the lift plate526.

Referring toFIGS. 6-10the actuator532further comprises an actuator rod534defining an lower mounting hole542, the actuator rod534being pivotally coupled to the transom plate508by a lower pin546extending through the lower mounting hole542and corresponding holes defined by a lower mounting bracket550. In this embodiment, the lower mounting bracket550is fixed to the transom plate508.

Referring toFIGS. 6 through 10, it will be appreciated that a jack plate500may including a spring mounted to the right of the actuator, a spring mounted to the left of the actuator, or both.

Referring toFIG. 11andFIG. 12, the spring564of the jack plate500further includes a male washer560and a female washer562disposed inside the socket538defined by the actuator casing536with the mounting screw552extending through the male washer560and the female washer. The male washer560and the female washer562are disposed between an upward facing surface of the end portion568of the spring housing566and a downward facing surface of the actuator casing536. The female washer562comprises a female surface556defining a cavity558. The male washer560comprises a male surface562. The male surface562of the male washer560is received in the cavity558defined by the female surface556of the female washer562. In an embodiment, the male surface562of the male washer560is seated against and in contact with the female surface556of the female washer562. In an embodiment the male surface562of the male washer560comprises at least one convex surface. In an embodiment the female surface556of the female washer562comprises a concave surface. In an embodiment the cavity558defined by the female surface of the female washer562has a shape corresponding to a cone.

Referring to allFIGS. 1-12, in an embodiment, the spring564of the jack plate500is biased to expand in length and the spring564is allowed to extend in length while the actuator532is activated to raise the lift plate526. In an embodiment, the spring564is biased to expand in length and the actuator532prevents the spring564from expanding in length when the actuator532is not activated. In an embodiment, the spring564is biased to expand in length and the spring is forced to contract in length while the actuator532is activated to lower the lift plate526.

Although gas springs are described for use with embodiments of the invention, the invention is not limited to gas springs. Other spring types are contemplated as well, for example helical springs, torsion springs, drawbar springs, and constant force springs, all optionally enclosed within a suitable casing, housing, or protective covering.

Although the present invention has been described with reference to particular embodiments, those skilled in the art will recognize that changes may be made in form and substance without departing from the spirit and scope of the invention. The embodiments described above are intended to be illustrative and not limiting.