This invention relates generally to a convertible dock ramp and stair assembly and more particularly to a convertible dock ramp which can be selectively place in a ramp configuration or a stair configuration.
It is often necessary to provide a bridging structure between two other structures, one of which is floating. For example, a gangway may be provided between a ship and a fixed dock, or a ramp may be provided between a fixed pier and a floating dock. As the water level rises or falls, the floating structure changes its height relative to the fixed structure, and accordingly the angle of the bridging structure relative to a horizontal reference plane changes.
A ramp-like structure is easier to traverse a relatively low angles, while a stair-like structure is easier to traverse at more steep angles. In the prior art, this fact is often accommodated by providing a bridging structure having pivotable stair treads which can remain level as the angle of the overall structure changes. Some of these units allow the treads to move into a position creating a ramp at very low angles. While these units provided the desired adjustability, they freely convert from one configuration to the other regardless of a user's wishes. Such units cannot be controlled from a remote location and can therefore be inconvenient. Furthermore, such units can create a safety hazard if a person's foot should be positioned between the stair treads as the unit is moving towards a ramp configuration.
Accordingly it is an object of the invention to provide a convertible dock ramp which can be locked in a stair configuration or a ramp configuration.
It is another object of the invention to provide a convertible dock ramp which can be remotely switched from a stair configuration to a ramp configuration.
It is yet another object of the invention to provide a convertible dock ramp which avoids injury to users' feet.
These and other objections are met by the present invention, which in one embodiment provides a convertible dock ramp having an upper end for being pivotally mounted to a mounting structure, and a lower end for resting on a second structure, the convertible dock ramp including: a pair of spaced-apart side frames each including substantially parallel upper and lower rails; and a plurality of steps each including a tread surface and a bottom surface connected by spaced-apart curved front and rear surfaces, the steps pivotally mounted between the side frames such that the tread surfaces are maintained substantially parallel to each other as the side frames pivot about the upper end, the steps further being pivotable between: a ramp configuration in which the tread surfaces collectively form a substantially flat ramp surface; and a stair configuration in which the tread surfaces collectively form a staircase-like structure; and a changeover mechanism for retaining the steps in a selected one of the ramp configuration and the stair configuration, while allowing the dock ramp to pivot about the upper end regardless of whether the steps are in the ramp configuration or the stair configuration, and further allowing the steps to pivot to remain substantially parallel to each other as the side frames pivot about the upper end, when the steps are in the stair configuration.
According to another aspect of the invention, the upper rails are mounted for pivotal motion about upper ends thereof, relative to the mounting structure, at a first hinge point; and the upper and lower rails are moveable between: a first position with the upper rails and the lower rails are in contact such that the tread surfaces are in the ramp configuration; and a second position with the lower rails spaced away from the upper rails such that the tread surfaces are in the stair configuration.
According to another aspect of the invention, the changeover mechanism includes: at least one actuator extending between the upper and lower rails, the at least one actuator selectively moveable between: a retracted position in which the upper and lower rails are disposed in the first position; and an extended position in which the upper and lower rails are forced to the second position.
According to another aspect of the invention, the actuator is electrically powered.
According to another aspect of the invention, the actuator resists deviation from a selected position when electrical power is removed from the actuator.
According to another aspect of the invention, the convertible dock ramp further includes: a battery operably connected to the actuator for supplying electric power thereto; and a solar cell operably connected to the battery for charging the battery.
According to another aspect of the invention, the convertible dock ramp further includes: a first switch disposed near an upper end of the convertible dock ramp and operably connected to the actuator for controlling motion of the actuator between the retracted and extended positions; and a second switch disposed near a lower end of the convertible dock ramp and operably connected to the actuator for controlling motion of the actuator between the retracted and extended positions.
According to another aspect of the invention, each of the steps includes spaced-apart end walls at laterally opposite ends thereof.
According to another aspect of the invention, each of the steps includes spaced-apart upper and lower tubes extending from each of the end walls.
According to another aspect of the invention, each of the steps is constructed from molded plastic.
The invention may be best understood by reference to the following description taken in conjunction with the accompanying drawing figures in which:
Referring to the drawings wherein identical reference numerals denote the same elements throughout the various views,
The upper ends of each of the upper rails 18 are pivotably mounted to the fixed pier 12 at first hinge points 36, and the upper ends of the lower rails are attached to the pier 12 at second hinge points 38. It should be noted that the side frames 16 may be directly attached to the pier 12, or they may be attached to an upper landing platform 40 having spaced-apart side members 42 which is in turn mounted to the pier 12 without affecting the operation of the convertible dock ramp 10. In either case, the pier 12 or the landing platform 40 forms a mounting structure for the convertible dock ramp 10 which is relatively stationary (that is, not pivotable relative to the outside environment). In the illustrated example, the second or lower hinge points 38 comprise upright slots 39 which receive hinge pins 44 carried by the lower rails 20, and thus allow the lower rails 20 to both pivot and translate relative to the pier 12. The lower ends of the lower rails 20 rest on the floating dock 14. A hinged dock board 46 may be provided to ease the transition between the convertible dock ramp 10 and the dock 14. In the illustrated example, one or more rollers 48 allow the convertible dock ramp 10 to freely translate relative to the dock 14.
The convertible dock ramp 10 has two basic configurations. When the upper and lower rails 18 and 20 are in contact, the tread surfaces 26 form a continuous, substantially planar ramp or walkway, as shown in
A changeover mechanism 48 allows a user to selectively determine whether the convertible dock ramp is in the ramp configuration or the stair configuration. In the example illustrated in
The upper ends of each of the upper rails 118 are attached to a fixed pier 112 or other relatively stationary structure at first or upper hinge points 136, and the upper ends of the lower rails 120 are attached to the pier 112 at second or lower hinge points 138. In the illustrated example, the lower hinge points 138 comprise upright slots 139 which receive a transversely-extending hinge rod 144 carried by the lower rails 120, and thus allow the lower rails 120 to both pivot and translate relative to the pier 112.
A changeover mechanism 148 comprises a control shaft 150 pivotably mounted relative to the pier 112. A first end of the control shaft 150 carries a control lever 152, and a second end of the control shaft 150 carries a control arm 154. When the control arm 154 is raised by rotating the control lever 152 towards the convertible dock ramp 110 as shown in
Appropriate controls are provided for the actuator 248. In the illustrated example, an upper switch 258 is mounted near the fixed pier 212 to which the convertible dock ramp 210 is mounted, and a lower switch 260 is mounted near the floating dock 214 on which the lower end of the convertible dock ramp 210 rests. The switches 258 and 260 are connected such that they can independently control the position of the actuator 248. This greatly improves the convenience in using the convertible dock ramp 210. For example, If a user departs the dock 214 in a boat and then returns several hours later, after the tide level has changed significantly, the convertible dock ramp 210 may be in the “stairs” configuration when the “ramp” configuration is desired. The lower switch 260 provides the ability to reconfigure the convertible dock ramp 210 without having to leave the dock 214. If desired, the convertible dock ramp 210 could also be provided with a wireless remote of a known type to control the actuator 248. When the actuator 248 is retracted, it forces the upper and lower rails 218 and 220 together into a ramp configuration, as shown in
An appropriate power source and controls of a known type are provided for the actuator 448. As shown in
This greatly improves the convenience in using the convertible dock ramp 410. For example, If a user departs the dock 414 in a boat and then returns several hours later, after the tide level has changed significantly, the convertible dock ramp 410 may be in the “stairs” configuration when the “ramp” configuration is desired. The lower switch 460 provides the ability to reconfigure the convertible dock ramp 410 without having to leave the dock 414. If desired, the convertible dock ramp 410 could also be provided with a wireless or wired remote of a known type to control the actuator 448.
The steps 422 may be constructed using various techniques; for example they could be machined from solid members our built up from sheet components. In the illustrated example, each step 422 is a hollow structure made from one or more pieces of molded plastic. An upper tube 433 (
The foregoing has described a convertible dock ramp. While specific embodiments of the present invention have been described, it will be apparent to those skilled in the art that various modifications thereto can be made without departing from the spirit and scope of the invention. Accordingly, the foregoing description of the preferred embodiment of the invention and the best configuration for practicing the invention are provided for the purpose of illustration only and not for the purpose of limitation.
This application is a continuation-in-part of application Ser. No. 10/907,556 filed Apr. 5, 2005 now U.S. Pat. No. 7,159,261.
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Number | Date | Country |
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8501769 | Apr 1985 | WO |
Number | Date | Country | |
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20070101516 A1 | May 2007 | US |
Number | Date | Country | |
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Parent | 10907556 | Apr 2005 | US |
Child | 11620780 | US |