STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
(NOT APPLICABLE)
BACKGROUND
The invention relates to a shallow water anchor and, more particularly, to an electrically driven shallow water anchor system incorporating a four-bar linkage and a ground spike.
Typical shallow water anchors are rigidly affixed to a marine vessel. When retracted, the shallow water anchor is positioned above the waterline and allows the vessel to function normally. When deployed, a ground spike is driven into the sea floor to anchor the vessel in place. Shallow water anchors typically function in less than 12 feet of water depth, though some extend as far as 15 feet.
Existing systems utilize hydraulic actuators that drop below the waterline during full deployment, which can result in corrosion and associated degradation of the system. Furthermore, these systems typically require the use of a powered hydraulic pump, which must be installed in the vessel, taking up valuable space.
Existing systems also lack a break away safety feature. Some utilize an audible alarm to indicate that the system is deployed on vessel power up, but there are many instances where users still drive away with the anchor deployed, which results in damage to the anchor as well as the vessel. When a hydraulic system fails, pressure relief must be activated to manually move the system. In some existing products, the system requires a total disassembly to recover from a failure of the hydraulic system.
Shallow water anchors are typically connected to vessels via bolts or the like, often requiring direct drilling through the transom of the vessel. Alternatively, existing anchors may attach to brackets via traditional bolts where the brackets are fixed to the vessel via transom drill holes. These designs are permanently affixed to the vessels and can cause issues for trailering and storing the vessel in covered storage.
Current anchors typically have a fixed maximum deployment depth, which is directly correlated to the retracted height on the vessel. Taller retracted heights allow for deeper deployment depths, but these systems experience issues with trailering and covered storage.
Current anchors often utilize a check valve to try to absorb boat movement. Due to the orientation of the hydraulic ram and check valve, however, most of the motion is lost in the linkage, causing the vessel to become unanchored. Existing designs typically also have no provision for bottom seeking or wake mitigation due to the rigid link between the linear actuator and the linkage arms.
SUMMARY
It is desirable to keep constant downward pressure on the anchor spike in the event that the vessel moves or is dislodged. With this configuration, the spike will be driven downward automatically to maintain vessel holding. It is also desirable to accommodate wake absorption, which allows the system to absorb wakes without causing damage to the system or vessel.
In an exemplary embodiment, a shallow water anchor system includes a four-bar linkage displaceable between a stowed position and a deployed position. The four-bar linkage has a drive arm pivotally secured at a proximal end on a first fixed pivot point, a pivot arm pivotally secured at a proximal end on a second fixed pivot point spaced from the first pivot point, and a link pivotally connected between distal ends of the drive arm and the pivot arm. A telescopic connector is secured between the drive arm and the pivot arm, and a ground spike is coupled with the link. The four-bar linkage maintains an orientation of the ground spike regardless of a position of the four-bar linkage.
The telescopic connector may include a linear actuator that may be displaceable between a retracted position in which the four-bar linkage is displaced to the stowed position and an extended position in which the four-bar linkage is displaced to the deployed position. A gas spring may be connected at one end to the linear actuator and at an opposite end to one of the drive arm and the pivot arm. The gas spring may be interposed between the linear actuator and the one of the drive arm and the pivot arm.
The telescopic connector may include a gas spring that is biased toward an extended orientation such that the four-bar linkage is biased toward the deployed position. The four-bar linkage may be displaced manually between the stowed position and the deployed position. The system may additionally include a latch that secures the four-bar linkage in the stowed position.
The telescopic connector may include a linear actuator having a distal end, where the system further includes a rigid housing fixed to one of the drive arm and the pivot arm, and a spring disposed in the rigid housing, where the distal end of the linear actuator engages the spring. The rigid housing may be interposed between the linear actuator and the one of the drive arm and the pivot arm. A compression rate of the spring may be constant or progressive. The compression rate may be greater in compressive force than the linear actuator.
In another exemplary embodiment, a shallow water anchor system includes a four-bar linkage displaceable between a stowed position and a deployed position. The four-bar linkage has a drive arm pivotally secured at a proximal end on a first fixed pivot point, a pivot arm pivotally secured at a proximal end on a second fixed pivot point spaced from the first pivot point, and a link pivotally connected between distal ends of the drive arm and the pivot arm. A connector is secured between the drive arm and the pivot arm, and a ground spike is coupled with the link. The connector is configured to bias the ground spike downward.
In yet another exemplary embodiment, a shallow water anchor system includes a four-bar linkage displaceable between a stowed position and a deployed position, a ground spike coupled with the four-bar linkage, and a shock absorber cooperable with one of the ground spike and the four-bar linkage and configured to absorb external forces on the ground spike.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other aspects and advantages will be described in detail with reference to the accompanying drawings, in which:
FIG. 1 shows the shallow water anchor system in a stowed position;
FIG. 2 shows the shallow water anchor system in a part-deployed position;
FIG. 3 shows the shallow water anchor system in a part-deployed position;
FIGS. 4 and 5 are a close-up view of the actuator for deploying and stowing the shallow water anchor system;
FIG. 6 shows a ramped interlock mechanism for securing the ground spike at a user-defined angle;
FIG. 6A is an end view of the link showing components of the interlock mechanism;
FIGS. 7 and 8 show the connection between a drive arm and a spur gear via a quick disconnect pin;
FIG. 9 shows an exemplary clamp for securing the system to a vessel;
FIG. 10 shows a variation of the ground spike incorporating an inline embedded gas shock;
FIG. 11 shows an alternative embodiment of the shallow water anchor actuator in a part-deployed position;
FIG. 12 shows the shallow water anchor of FIG. 11 in a stowed position;
FIG. 13 shows the shallow water anchor of FIG. 11 in a fully deployed position;
FIGS. 14 and 15 show a variation of the shallow water anchor incorporating a progressive spring;
FIGS. 16 and 17 show a variation with a gas spring connected between the linear actuator and the linkage;
FIG. 18 shows a variation using a gas spring instead of a linear actuator;
FIGS. 19 and 20 show a variation incorporating a constant K-rate spring;
FIG. 21 shows a variation without a gas spring or linear actuator; and
FIG. 22 shows a variation incorporating a clutch.
DETAILED DESCRIPTION
FIGS. 1 and 2 show a shallow water anchor system 10 of the described embodiments secured on a marine vessel MV. An actuator drives a four-bar linkage 12 between a stowed position (FIG. 1) and a deployed position (part-deployed position shown in FIG. 2).
A ground spike 14 is coupled with the four-bar linkage 12. When deployed, the ground spike 14 is driven into the sea floor to anchor the vessel MV in place. The four-bar linkage 12 maintains an orientation of the ground spike 14 regardless of a position of the four-bar linkage 12.
With reference to FIG. 3, the four-bar linkage 12 includes a drive arm 16 that pivots on a first fixed pivot point 18, and a pivot arm 20 that pivots on a second fixed pivot point 22 spaced from the first pivot point 18. A link 24 is pivotally connected between distal ends of the drive arm 16 and the pivot arm 20, and the ground spike 14 is connected to the link 24. With this configuration, an orientation of the ground spike 14 relative to the four-bar linkage 12 is kept constant regardless of a position of the four-bar linkage 12. The four-bar linkage 12 is coupled to a frame member 25.
FIGS. 4 and 5 show details of an exemplary actuator for driving the shallow water anchor system 10 between the stowed position and the deployed position. The exemplary actuator is similar to the actuator described in U.S. Pat. No. 8,752,498, the contents of which are hereby incorporated by reference. A motor 26 is connected to a power source via a wire harness (not shown) and connects to the vessel MV via two power leads allowing for simple installation and effective use of space. A singular switch may be provided to activate the system. In an exemplary construction, there is no circuit board or chip controlling the system. In other embodiments, Bluetooth or Wifi systems incorporating a circuit board may be used to control the system.
The motor 26 is configured to reciprocate a rack 28 between a retracted position and an extended position. As would be appreciated by those of ordinary skill in the art, reciprocation of the rack 28 can be achieved using various means. In the exemplary construction shown in FIG. 4, the motor 26 drives a lead screw 30 via a gearbox 32. A lead screw nut 34 is fixed to or otherwise embedded in the rack 28 and engages threads of the lead screw 30. As such, as the lead screw 30 is rotated by the motor 26, the lead screw nut 34 and thereby the rack 28 are displaced linearly.
The rack 28 engages with a spur gear 36 that is connected to a proximal end of the drive arm 16. With particular reference to FIG. 5, as the rack 28 is extended (downward in FIG. 5), the drive arm 16 is displaced clockwise about the first pivot point 18. Displacement of the drive arm 16 displaces the entire four-bar linkage 12.
The drive system including the motor 26, the rack 28 and the spur gear 36 are mounted to the vessel MV above the waterline, which reduces the potential for corrosion-related damage. As shown, the drive system is compact and fully self-contained, allowing for effective and efficient use of space.
In some embodiments, with reference to FIGS. 7 and 8, the drive arm 16 is connected to the spur gear 36 via a quick disconnect pin 38. Decoupling of the drive arm 16 from the spur gear 36 allows the user to easily reposition the system in the event of a motor failure or power loss. Removing the pin 38 also enables the user to manually extend or retract the system.
FIGS. 11-13 show details of another exemplary actuator for driving a shallow water anchor system 110 between the stowed position and the deployed position. A motor 126 is connected to a power source or may be battery-powered. The motor 126 is mounted to the system such that it remains above the waterline, which reduces the potential for corrosion-related damage. The motor 126 is configured to extend and retract a strut 148 that is pivotally connected to both the drive arm 116 and the pivot arm 120. The anchor system 110 is shown in the retracted position in FIG. 12 when the strut 148 is fully retracted. The anchor system 110 is shown in the extended position in FIG. 13 when the strut 148 is fully extended. The strut 148 may be mounted by removable pins 138 to both the drive arm 116 and the pivot arm 120 so that either pin can be removed so that the user can easily reposition the system in the event of a motor failure or power loss. As shown, the drive system of anchor system 110 is also compact and fully self-contained, allowing for effective and efficient use of space. Other features of the shallow water anchor system 110 are substantially similar to corresponding features of the shallow water anchor system 10 described above and below.
With reference to FIG. 6, the ground spike 14 may be connected to the link 24 via a ramped interlock mechanism 40 that is configured to secure the ground spike 14 at a user-defined angle relative to the four-bar linkage 12. The ramped interlock mechanism 40 is provided with a plurality of ramp features at discrete angular positions. In the event that an excessive lateral load is applied to the ground spike 14, the ramped interlock mechanism 40 will allow the ramps to skip, thereby protecting the system as a whole and the vessel MV at the attachment point. FIG. 6A is an end view of the link 24 showing components of the interlock mechanism 40. A plurality of radius splines 40a (eight in FIG. 6A) prevent two splined hubs containing locking teeth 40b from rotating within their respective parts. The locking teeth 40b provide a holding force under normal loads. A stack of Belville spring washers may be positioned on a post 40c that serve to keep constant force on the locking teeth 40b. Once a great enough force is seen in the anchoring spike 14, the springs would compress and allow the teeth 40b to disengage, thereby allowing the spike 14 to rotate upward out of the way.
FIG. 9 shows a clamp 42 that is configured to secure the system 10, 110 to the vessel MV. The clamp 42 may be secured to the frame member 25. In some embodiments, the clamp 42 utilizes thumb screws 44 for securing the system 10, 110 to the marine vessel MV. The clamp 42 enables the system 10, 110 to be rapidly rigidly affixed to the vessel MV without requiring tools. The clamp 42 similarly allows for rapid removal of the system for transport or storage. The clamp 42 thus allows for smaller lower-cost vessels to utilize the system and allows for the system to only be installed and utilized when needed.
In some embodiments, the drive arm 16, 116 and the pivot arm 20, 120 may include telescoping sections so that links of the drive arm 16, 116 and the pivot arm 20, 120 can be adjusted. The telescoping structure allows for the retracted height of the system to be adjusted on the fly, which enables the user to increase or decrease the maximum deployment depth. The retracted height of the system can thus be minimized for trailering and storage. In the event that the user requires a deeper deployment depth while using the system, the user can rapidly and easily extend the length of the system without requiring tools.
As shown in FIG. 10, the ground spike 14 may be provided with an inline embedded gas shock 46. The gas shock 46 provides for maximum vessel holding during rough sea conditions due to the shock being in line with the ground spike 14. That is, as the vessel is shifted in use by wind or rough seas or the like, the gas shock 46 can absorb boat movement to maintain a secure ground connection and improve functionality. In some embodiments, the gas shock 46 may be located between upper and lower portions of the spike. The shock absorber may alternatively be a hydraulic shock or a resilient material such as rubber or foam.
FIGS. 14-22 show variations of the shallow water anchor system that endeavor to keep constant downward pressure on the ground spike and/or accommodate wake absorption. With reference to FIGS. 14 and 15, the anchor system 210 interposes a rigid housing 252 at a distal end of a strut or linear actuator 248 connected between the drive arm 216 and the pivot arm 220. The linear actuator 248 includes a telescopic or extension arm 248a. The rigid housing 252 houses a progressive spring 254, and the extension arm 248a engages the spring 254 in the housing 252. The housing 252 includes a slot 256 that enables displacement of the extension arm 248a in the housing 252. The extension arm 248a is retained in the slot 256 via a concentrically mounted pin 258.
The illustrated variation allows for wake absorption and bottom seeking benefits without the need for constant power. The use of a progressive spring allows the weaker portion of the spring to be initially compressed and stay compressed during anchoring. In the event of the ground spike becoming dislodged from the seafloor, the compressed portion of the spring will expand and cause the spike to re-lodge in the seafloor. The stronger portion of the spring is intended to not be initially compressed. In the event that the vessel is subject to wake, the weight of the vessel will compress the spring rather than cause damage to the system or vessel.
FIGS. 16 and 17 show a variation where a rigid linkage is used to adapt a gas spring to the linear actuator 348 of the anchor system 310. In this variation, a gas spring 360 is connected at one end to the linear actuator via a gas spring coupler 362 and at an opposite end to one of the driver arm 316 and the pivot arm 320 (driver arm 316 in FIGS. 16-17). That is, as shown in FIGS. 16 and 17, the gas spring 360 is interposed between the linear actuator 348 and the one of the driver arm 316 and the pivot arm 320. Like the variation shown in FIGS. 14 and 15, the variation shown in FIGS. 16 and 17 is fully mechanical and low-cost. The use of a progressive gas spring could provide both active bottom seeking and wake absorption.
FIG. 18 shows a variation using a gas spring 464 instead of a linear actuator to deploy the shallow water anchor system 410. The gas spring 464 is connected between the drive arm 416 and the pivot arm 420 as shown. In some embodiments, the gas spring 464 is biased toward an extended orientation such that the four-bar linkage 412 is biased toward the deployed position. In this variation, the four-bar linkage 412 is displaced manually between the stowed position and the deployed position. The system may include a latch 466 that secures the four-bar linkage 412 in the stowed position. That is, the system can be retained in the retracted position through the use of a positive engaging mechanical latch 466. The latch 466 may be made of a resilient or semi-rigid material for being stretched around the shallow water anchor system and engaged by a catch to retain the anchor in the stowed position. The system can also be interfaced with a length of rope and cleat for quick deployments/retractions.
By using a gas spring in lieu of a linear actuator, a substantial weight reduction is achieved. Additionally, the customer install as well as regular removal of the system is simplified due to the lack of electronics. Due to the nature of the gas spring, the system will constantly seek bottom and be able to absorb wakes proportional in size to the entire travel depth of the system.
FIGS. 19 and 20 show a variation similar to that shown in FIGS. 14 and 15. The system 510 incorporates a rigid housing 552 between the extension arm 548a of the linear actuator 548 and one of the drive arm 516 and the pivot arm 520. A distal end of the linear actuator 548 such as the extension arm 548a engages the spring 554, and the extension arm 548a of the actuator is retained in the slot through use of a concentrically mounted pin 558.
In this variation, a compression rate of the spring 554 may be constant and may be greater in compressive force than the linear actuator 548. When the system/vessel is exposed to wake, the spring compresses, which mitigates the impact of loading the system has to sustain.
FIG. 21 shows a variation without any gas spring or a linear actuator. Instead, the system 610 utilizes the weight of the linkage arms and spike to deploy. Once deployed, the system can be manually retracted by the user. The system 610 can then be retained in the retracted position through the use of a positive engaging mechanical latch. The system 610 can also be interfaced with a length of rope and cleat for quick deployments/retractions. This variation provides a low-cost fully manual system without rigid links in the infrastructure, enabling the system to have full range of free motion to absorb wake.
FIG. 22 shows a variation incorporating a clutch that will release to allow the system to extend/deploy. The system includes a motor 726 that is configured to reciprocate a rack 728 between a retracted position and an extended position. The rack 728 engages with a spur gear 736 that is connected to a proximal end of the drive arm 716.
When the clutch 768 releases to allow the system to extend/deploy, the weight of the assembly is inherently bottom seeking. The clutch can be engaged allowing electronic drive when desirable to retract the system. By use of the clutch, the system can inherently mitigate wake and perform similar to a hydraulic system.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
Patent Application
20250026450
