None
The present invention generally relates to systems for marine boat ladders generally. More specifically, the present invention relates to systems enabling retractable marine boarding ladders.
Generally, various embodiments of the present invention comprise an improved marine boarding ladder. As the skilled artisan will recognize, marine boarding ladders, e.g., swim ladders, and the like, are well known.
However, the known marine ladders do not incorporate mechanisms to hold the ladder in the deployed position nor do they reduce the force required to raise the ladder into a stowed position or automatically retract the ladder into the stowed position.
For example, some known ladders rotate at a point near the top of the ladder to stow or deploy. This requires application of force by the user throughout the process and may be quite awkward and difficult for some users. Some ladders also comprise a telescoping lower section that must be manually extended in order to achieve the deployed position and manually retracted. Still other ladders are permanently affixed to the boat. One feature all known non-permanent ladders have in common is that they all require a user to apply force throughout the processes of stowing and deployment sufficient to move the ladder into a stowed or deployed position.
Thus, a need exists in the art generally for a marine ladder that provides movement assistance for the transition from a deployed position to a stowed position. A further need exists in the art for a deployed marine ladder that, following an initial application of force, automatically stows without further user intervention.
The present invention addresses these, among other, needs.
The present system is directed in various embodiments to marine ladders comprising movement assistance for the transition from a deployed position to a stowed position and from the stowed position to the deployed position. In certain embodiments, the gas springs and associated pivot point brackets hold the deployed ladder biased in the deployed position with a biasing force that may be overcome by application of force by the user to initiate an automatic stowing process. Alternatively, and most preferably, the initial force to initiate the automatic stowing process is provided by the force of water flowing against an aft-mounted ladder as a result of the boat moving forward. The remainder of the force required to complete the automatic stowing process is provided by the gas springs. In the case of movement assistance from the stowed to deployed position, the user applies force to initiate the transition while the gas springs apply an opposing force that slows the transition for safety.
While the invention is amenable to various modifications and alternative forms, specifics thereof are shown by way of example in the drawings and described in detail herein. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.
The present invention provides a marine ladder 100 that is connected to a boat for boarding and disembarking and comprising a fixed section 200 and a rotatable section 300. As illustrated in Figures, the ladder 100 is preferably fixedly mounted to the aft portion of boat, however, alternate locations for the ladder 100 mounting are within the scope of the present invention. Mounting bracket 102, having a right side, a left side, a front side and a rear side is mounted to the boat surface by a variety of means, including bolting, screwing and the like, all of which will be well known to the skilled artisan.
Fixed section 200 of ladder 100 comprises first 110 and second 120 handrails. First handrail 110 is shown with a first fixed proximal section 112 that is mounted or otherwise affixed to the left side of mounting bracket 102 at point A, proximate the rear side of bracket 102, a first fixed curvilinear section 114 connected to the first proximal section 112 and a first fixed extension section 116 connected to the fixed curvilinear section 114.
The second handrail 120 is illustrated with a second fixed proximal section 122 mounted or otherwise affixed to the right side of mounting bracket 102 at point B, proximate the rear side of bracket 102, a second fixed curvilinear section 124 connected to the fixed proximal section 122 and a second fixed extension section 126 connected to the fixed curvilinear section 124. Fixed section 200 further comprises brackets 118 and 128 fixedly attaching fixed extension sections 116, 126, respectively, to the front side of mounting bracket 102. Certain embodiments of fixed section 200 may comprise, as illustrated, one or more step elements 150 fixedly connected between the first and second handrails 110, 120.
Fixed extension sections 116 and 126 comprise distal ends 117, 126, respectively, where channels C1, C2 are defined.
Rotating section 300 of ladder 100 is a rigid structure that rotates in a single plane relative to fixed section 200. Rotating section 300 comprises a left handrail L, capable of aligning with first handrail 110 of fixed section 200; a right handrail R, capable of aligning with second handrail 120 of fixed section 200 and with one or more step elements 150 disposed therebetween as in the Figures. Left and right handrails L, R each comprise a proximal end P, P′, that are rotatingly disposed within channels C1, C2, respectively, of first and second handrail 110, 120. As illustrated, proximal ends P, P′ of left and right handrails L, R are rotatingly affixed within channels C1, C2 by a fastener 147, e.g., a nut and bolt system or the equivalent as the skilled artisan will readily recognize, each such equivalent fastener is within the scope of the present invention.
Rotating section 300 further comprises two pivot point brackets B, B′ fixedly attached to the top T of each of proximal ends P, P′, respectively, of left and right handrails L, R. As can be seen in the Figures, when rotating section 300 is transitioning to the straightened, deployed position, the pivot point brackets B, B′ engage channels C1 and C2, respectively, extending partially therethrough in certain embodiments. Pivot point brackets B, B′, are attached to the top T of each of proximal ends P, P′ of left and right handrails L, R, with an angle α therebetween. Angle α is illustrated as obtuse and approximately 135 degrees, though other angle degrees may be functionally equivalent and are also within the scope of the present invention.
Identical first and second gas springs 400, 400′, comprising a gas-filled cylinder 402, 402′ and a rod 404, 404′, wherein the rod 404, 404′ is subject to the force of the gas within cylinder 402, 402′ and is translatable into and out of the cylinder 402, 404′ depending on the magnitude of the opposing forces that the rod is subjected to. As shown in
Having described the structure of the present invention, we now turn to the operation of the subject ladder.
At a point in the transitional downward process, the mass of the rotating section 300 provides a force sufficient to overcome force F1, without aid of the user's added downward force on rotating section 300 as seen in
The continued freely downward transition of rotation section 300, i.e., without need of any additional downward force provided by, e.g., a user, results in the deployed position which is illustrated in
Once the deployed position of
Turning now to
At a point in the upward transition from deployed to stowed, the force F1 will overcome the downward forces, i.e., the mass of, on the rotating section. At this point, the forces F1 provided by gas springs 400, 400′ work to extend the rods 404, 404′ from the gas cylinders 402, 402′ with concurrent and smooth upward rotation of the rotating section as in
The present invention should not be considered limited to the particular examples described above, but rather should be understood to cover all aspects of the invention. Various modifications, equivalent processes, as well as numerous structures to which the present invention may be applicable will be readily apparent to those of skill in the art to which the present invention is directed upon review of the present specification.