Abstract:
The docking apparatus of the present invention is designed and configured to maintain a floating dock with a boat attached thereto within deep enough areas of a lake, river, or the like so that the boat or dock does not collide with land as it would if the water was shallow. The water level of lakes, rivers, and the like vary depending on the time of the year. A boat that is docked for an extended period of time may collide with the floor of the lake, river, or the like as the water level decreases. The docking apparatus of the present invention has a depth sensing system that senses the water depth directly underneath the floating dock and the boat. When the water depth decreases below a predetermined level, the docking apparatus of the present invention energizes an electric motor to move the floating dock and boat along a chain and away from shore onto deeper areas where the water depth is greater than the predetermined level.

Description:
BACKGROUND OF INVENTION 
       [0001]    1. Field of Invention 
         [0002]    The present invention is related to an apparatus and method of preventing a floating dock and a boat from being docked on areas of a lake, river, or the like where the water depth is below a predetermined value. More particularly, the invention relates to a docking apparatus having a depth sensing system that periodically senses the water depth directly underneath a floating dock and boat. When the water depth decreases below a predetermined value, the present invention energizes an electric motor to move the tloating dock and boat along a chain and onto deeper waters where the water depth is greater than the predetermined level. 
         [0003]    2. Description of Prior Art 
         [0004]    Large bodies of water, such as lakes and rivers, often have docks or docking systems for boats. People who own homes along the shore of lakes and rivers will often dock their boats for extended periods of time, for example, through the entire cold winter season. It is well known to those skilled in the art that docking boats along the shore of lakes and rivers creates problems caused by the expected variation in the water level. The amount of water or the water level in a lake or river varies throughout the year for many reasons. For example, the water level increases in the late winter and early spring months as the snow packs in the mountains melt and the rain season begins. On the other hand, the water level in lakes and rivers typically drop substantially in the summer months as the water is released to reservoirs for use by the public. 
         [0005]    These variations in the water level of lakes, rivers, and the like, have always presented difficulties for operators of small watercrafts. Boats are typically docked in areas along the shore of the lakes, rivers, and the like, that have shallower water depths. As the water level drops at certain times of the year, docked boats run the risk of being pushed down against land and damaging its propeller, hull, and other components. Additionally, as the water level drops, the docks to which the boats are attached are also pushed against land. Once a dock ends up on land, it is extremely difficult to push it back into the water. 
         [0006]    Several docking techniques and docking system designs have been developed to prevent or minimize the damage caused to boats and docks by the variation in water level. U.S. Pat. No. 3,088,287 teaches a device that utilizes rails that is secured to the shore and extended downwardly at an angle to the surface of the water. The rails are long enough to reach the lowest anticipated water level. A connecting bar is attached to the watercraft at one end and to the rails on the other end. The connecting bar is allowed to slide along the rails so as to allow the watercraft rise and fall with the change in the water level. Although this device allows the watercraft to be secure as the water level rises and falls, it fails to protect the watercraft from damage resulting from its collision with the floor of the lake or river when the water level falls too much. 
         [0007]    U.S. Pat. No. 5,138,965 also teaches another solution with a railing system to which the watercraft is attached and allows the watercraft to safely move up and down as the water level rises and falls. U.S. Pat. No. 4,697,538 teaches a similar solution but uses an extended arm that pivots up and down to allow the watercraft rise and fall safely with the water level. However, none of these solutions remotely address the issue of the watercraft being damaged by its collision with the floor of the lake or river when the water level drops too far. 
         [0008]    The most common solution to this problem currently practiced by those skilled in the art is a manual system consisting of attaching the watercraft to the side of a floating dock. The floating dock is tethered to the floor of the lake or river at one end and to the shore of the lake or river at the opposite end with a chain or a strong rope. As the water level drops and the lake or river becomes shallower, the owner of the watercraft uses the chain or rope to move the floating dock further away from the shore so that the watercraft would be in a deeper area of the lake or river. Thus, by pushing the watercraft further from the shore, its collision with the floor of the lake or river when the water level drops too much is averted. On the other hand, when the water level rises, the owner of the watercraft utilizes the chain or strong rope to pull the floating dock and watercraft closer to shore for easier access. 
         [0009]    Constantly having to move the floating dock and watercraft closer and away from the shore of a lake or river to prevent the watercraft from colliding with the floor of the lake or river as the water level varies is extremely burdensome. Some watercraft owners will often hire someone to periodically move their floating dock and watercraft as the water level rises or falls. However, hiring someone for this task can be a very expensive proposition. 
         [0010]    Unless these and other practical problems associated with these docking systems or methods are resolved, the risk of boats and other watercrafts from being damaged by their collision with the floor of the lakes or rivers as the water level drops will persist and any effective docking device will fail to be realized. 
       SUMMARY OF THE INVENTION 
       [0011]    Accordingly, the present invention has been made in view of the above-mentioned disadvantages occurring in the prior art. The present invention is a docking apparatus with a timer that periodically activates a depth sensing system to sense the water depth directly underneath the floating dock and boat. When the water depth is below a predetermined level, a strong electric motor is energized to move the floating dock and boat linearly along a chain and further away from the shore of the lake on to a deeper section of the lake. 
         [0012]    It is therefore a primary object of the present invention to provide automatic movement of the floating dock away from the shore and on to deeper waters whenever the water depth underneath the floating dock is low enough to risk the boat being damaged by a collision with land. 
         [0013]    Another object of the present invention is to provide an automatic and periodic measurement of the water depth directly underneath the floating dock so as to automatically move the boat away from harm way when the water level drops. 
         [0014]    Yet another object of the present invention is to reduce the installation and operation complexity of the docking apparatus so that the boat owner can install and operated it with ease. 
         [0015]    The above objects and other features of the present invention, as well as the structure and operation of various embodiments of the present invention, are described in detail below and with reference to the accompanying drawings. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0016]    The accompanying drawings which are incorporated by reference herein and form part of the specification, illustrate various embodiments of the present invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention. In the drawings, like reference numbers indicate identical or functional similar elements. A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: 
           [0017]      FIG. 1  is a sectional view of the docking apparatus of the present invention in its assembled state and installed on a floating dock to which a boat is attached. 
           [0018]      FIG. 2  is an exploded view of the docking apparatus of the present invention to show the long plate that slides down inside a structural tubular frame. 
           [0019]      FIG. 3  is a perspective view of the mechanical interaction between the pulley that is attached to the electric motor and the chain. 
           [0020]      FIG. 4  is a side view of the chain anchored at both the front end and the back end while running over and around the pulley. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0021]    Reference will now be made to the drawings in which various elements of the present invention will be given numerical designations and in which the invention will be discussed so as to enable one skilled in the art and make use the invention. 
         [0022]    The present invention comprises a docking apparatus  100  with a timer  10 , a depth sensing system  20 , and an electric motor  30  that is attached to a pulley  40  that pulls a chain or cable  50 . The docking apparatus  100  has a primary source of electrical power which can be a heavy duty battery, direct connection to high-voltage power line, a regular electrical wall outlet, or even solar panels. The docking apparatus  100  is rigidly attached to a floating dock  200  and the chain  50  has a front end  51  that is rigidly attached to the floor of the lake while the back end  52  is rigidly attached to the shore. The timer  10  activates the depth sensing system  20  to periodically check the water depth directly underneath the floating dock. When the depth sensing system  20  determines that the water depth is less or greater than a predetermined amount, the electric motor  30  is energized to rotate the pulley  40 . As the pulley  40  rotates, it begins moving the floating dock  200  along the chain  50  away from the shore on to a deeper section of the lake. Once the depth sensing system  20  determines that the water depth underneath the floating dock  200  is greater than a predetermined amount, the motor  30  stops, and the floating dock  200  stays at its new location. 
         [0023]    Application of the present invention is with floating docks to which various watercrafts can be attached. The watercrafts can range from small boats to large ships, submarines, house boats, and even jet-skis. In addition, instead of being rigidly attached to a floating dock, the present invention can be rigidly attached to the watercraft. Finally, the present invention can be used in any body of water, such as lakes, rivers, oceans, water reservoirs, and the like. However, the preferred embodiment described herein has been configured to be used on a floating dock that is on a lake and to which a boat is attached. It will be appreciated by those skilled in the art that the principles of this invention may be applied to any of the abovementioned configurations without departing from the spirit of the present invention. 
         [0024]      FIG. 1  shows a perspective view of the docking apparatus  100  of the present invention in its assembled state and installed on a floating dock to which a boat is attached.  FIG. 2  shows an exploded view of the docking apparatus  100  of the present invention to depict in greater detail the various components that comprise the docking apparatus  100 . A principal component of the present invention is the depth sensing system  20  which, in the preferred embodiment of the present invention, comprises an air pump  21 , a pressure sensor  22 , and a hose  23 . The hose  23  is connected to the air output nozzle  21   a  of the air pump  21 . The pressure sensor  22  is hydraulically connected to the hose  23  so as to be able to sense the pressure inside the hose  23 . When the depth sensing system  20  is energized, the pump  21  injects air directly into the hose  23  to which it is connected. Then the pressure sensor  22  senses the pressure inside the hose  23 . When the pressure inside the hose  23  is less than a predetermined value, the pressure sensor  22  allows the depth sensing system  20  to output an electrical current that then energizes a relay  26  to allow a large electrical current to energize the electric motor  30 . 
         [0025]    As the electric motor  30  is energized, it generates high torque to rotate a pulley  40 . Both the electric motor  30  and the pulley  40  are heavy duty items designed to support and pull heavy loads. The pulley  40  has a small diameter to operate under high torque and slow speeds. The pulley  40  is preferably cast from a strong material, such as metal, and has a series of pockets  41  that allow the links  51  of the chain  50  to nest in them as the pulley  40  is rotated. The exact number of pockets  41  depends on the size of the chain  50 . The preferred embodiment of the present invention uses a pulley  40  having 5 pockets  41 . The pockets  41  mechanically engage with the chain  50  that is wrapped partially around the pulley  40 , as shown in  FIG. 3 . As the pulley  40  is rotated, the pockets  41  pull against the chain links  51  so as to move the chain  50  in the direction of the rotation of the pulley  40 . 
         [0026]    As shown in  FIG. 4 , the chain  50  used in the preferred embodiment of the present invention can be several yards in length. The chain  50  is arranged longitudinally along the floating dock  200  with the front end  51  rigidly attached to the floor or bottom surface of the lake at a predetermined distance away from the shore. Similarly, the back end  52  of the chain  50  is rigidly attached to the shore of the lake outside of the water. As such, as the motor  30  is energized to rotate the pulley  40 , the pockets  41  pull against the chain  50 . Since the chain  50  is rigidly attached at both its ends  51  and  52 , the resulting force moves the pulley  40  and anything attached to it linearly along the length of the chain  50 . Since the pulley  40  is attached to the motor  30  which is then attached to the floating dock  200 , the entire floating dock  200  moves linearly along the chain  50  as the pulley  40  is rotated by the motor  30 . 
         [0027]    In essence, the chain  50  that is rigidly attached to the shore and the floor of the lake serves as a railing system to guide the movement of the floating dock  200 . The chain  50  functioning as a railing system may appear similar to the rails used in U.S. Pat. No. 3,088,287 and U.S. Pat. No. 5,138,965. However, a substantial difference with the present invention is that the chain  50  does not extend along the shore or the floor of the lake. The front end  51  of the chain  50  in the present invention is rigidly attached to the floor of the lake at a substantial distance away from the shore. On the other hand, the back end  52  of the chain  50  is rigidly attached to the shore of the lake. This is a very important distinction because the boat  300  in the present invention is moved away from the shore of the lake and on to deeper areas of the lake as the water level drops. On the other hand, the prior art listed above moves the boat along a fixed distance from the shore of the lake rather than away from the shore as the water level of the lake drops. This is an important distinction because the shore of a lake rarely ever has a consistent steepness and shape. Hence, as the boat is moved along a fixed distance from the shore, there is a high likelihood that it will collide with the floor of the lake due to the inconsistent steepness and shape. The prior art listed above does not have any system that senses the water depth to ensure that the boat does not collide with land. Rather, the prior art blindly moves the boat along a fixed distance from the shore of the lake. 
         [0028]    As shown in  FIG. 4 , the chain  50  in the present invention must be attached to the floating dock  200  in an orderly fashion so that it is kept longitudinally in a straight line along or underneath the floating dock  200  without any entanglements and with a natural catenary curve at the ends of the dock  200  so that the chain  50  will not interfere with a boat or its propeller as the boat passes close to the floating dock  200 . 
         [0029]    Finally, the docking apparatus  100  of the present invention has a timer  10  that is used to periodically activate the depth sensing system  20 . The timer  10  can be of the type that is commonly used in sprinkler systems or household appliances. It simply has a clock that can be programmed to release an electrical current once a day or even once a week. The electrical current that is released would traditionally be used to energize a sprinkler system, an appliance, or some house lights. But instead, in the present invention, the electrical current periodically released by the timer  10  at predetermined times is used to energize the depth sensing system  20 . 
         [0030]    In the preferred embodiment of the present invention, however, the timer is within a microprocessor that is programmed to periodically energize the depth sensing system  20 . The microprocessor is also part of the depth sensing system  20  as the component that calculates or estimates the water depth underneath the floating dock  200 . The microprocessor, as part of the depth sensing system  20 , calculates the water depth based on the pressure inside the hose  23  as sensed by the pressure sensor  22 . 
         [0031]    Hereinafter, the method of installing the docking apparatus  100  of the present invention to a floating dock  200  and the operating method thereof will be given. 
         [0032]    The docking apparatus  100  of the present invention is installed by directly attaching it to a floating dock  200 , preferably to a rigid post  210  that is part of the floating dock  200 . The timer  10  and the depth sensing system  20  are attached to a long plate  75  that slides down inside a structural tubular frame  70 . Although the timer  10  and the depth sensing system  20  are attached to the same plate  75 , they are spaced apart with sufficient distance to allow an operator to access each without disturbing the settings of the other. In addition, although separate from each other, the timer  10  and depth sensing system  20  always maintain an electrical connection with each other. The tubular frame  70  with the plate  75  inside is rigidly attached to the post  210 . Thereafter, the electric motor  30  is rigidly attached to the floating dock  200 , preferably on to the floor  220  and adjacent to the post  210  for greater stability and accessibility. With the motor  30  rigidly attached to the floating dock  200 , the pulley  40  is attached to the rotating shaft  31  of the motor  30 . Then the motor  30  is electrically connected to the depth sensing system  20 . Alternatively, the depth sensing system  20  can be in communication with the motor  30  via Radio Frequency (RF) waves. In essence, when appropriate, the depth sensing system  20  would emit an RF signal that closes the relay  26  that is integral with the motor  30  allowing electrical current to energize the motor  30 . 
         [0033]    Once the docking apparatus  100  of the present invention is attached to the floating dock  200 , the floating dock  200  is placed on the water near the shore and positioned with its longitudinal section being perpendicular to the shore. The back end  52  of the chain  50  is then rigidly anchored to the shore outside the water. On the other hand, the front end  51  of the chain  50  is rigidly anchored to the floor of the lake in a deep section of the lake and far enough from shore to be past the farthest extension of the floating dock  200 . Rather than anchoring the chain directly to the shore and floor of the lake, the anchor points of the chain  50  may be large blocks of concrete that are heavy and stable enough to hold the floating dock  200  at a fixed location and secured against wind and waves. As the chain  50  is anchored, it is passed over and around the pulley  40  that is attached to the motor  30  so that it mechanically engages the pockets  41  of the pulley  40 , as shown in  FIGS. 3 and 4 . Finally, the chain  50  is pulled taut before fully being anchored in place so as to build tension thereon but ensuring that the chain&#39;s  50  natural catenary curve lay will not interfere with a boat propeller as it passes close to the floating dock  200 . 
         [0034]    Once the chain  50  is fully taut and anchored, the depth sensing system  20  needs to be calibrated and programmed. First, a hose  23  is connected to the outlet  21   a  of the pump  21 . The hose  23  must be longer than the lowest level that the water underneath the floating dock  200  can reach without letting the boat collide with land. It is preferred that the hose  23  be long enough to reach the floor of the lake at the deep section at which the front end  51  of the chain  50  is anchored. With the hose  23  connected to the outlet  21   a  of the pump  21 , the hose  23  is dropped into the water. Secondly, the hose  23  is slowly lifted out of the water until the end of the hose  23   a  is at the lowest depth that the water level can reach before the boat runs the risk of colliding with land. Holding the hose  23  at this position, the pressure sensor  22  is used to sense the pressure inside the hose  23 . The pressure sensor  22  is adjusted to the predetermined pressure value at which the motor  30  must be energized to move the floating dock  200  further away from the shore and on to deeper water. With the pressure sensor  22  calibrated and programmed, the entire hose  23  is allowed to drop into the water. The preferred embodiment includes a screen  23   b  attached to the end of the hose  23   a  so as to prevent the hose from being clogged with debris which may result in false readings by the pressure sensor  22 . 
         [0035]    With the depth sensing system  20  properly set and programmed, the operator uses the timer  10  to program the times at which the depth sensing system  20  needs to sense the water depth directly underneath the floating dock  200 . The timer  10  can be set to activate as often as 52 times per week although it is often not necessary to sense the water level more than once, or two times per day. 
         [0036]    Once the docking apparatus  100  of the present invention is properly installed and programmed, the operator and owner of the boat no longer needs to manually move the floating dock when the water level drops. Instead, at the predetermined times programmed in the timer  10 , the depth sensing system  20  will sense the water depth directly underneath the floating dock  200  by sensing the pressure inside the hose  23  after the air pump  21  injects air into the hose  23 . When the water level or water depth underneath the floating dock  200  is high, the end of the hose  23   a  that is resting on the floor of the lake will allow for high levels of pressure within the hose  23 . In essence, the amount of water inside the hose  23  will extend from the floor of the lake up to the water level. The higher the water extends up or the greater the water column, the more force or pressure is required by the pump  21  to inject air through the hose  23 , thus the higher the pressure inside the hose  23 . As the water level or water depth underneath the floating dock  200  decreases, the pressure inside the hose  23  decreases because the height extension or water column inside is reduced and less pressure is required by the pump  21  to inject air through the hose  23 , thus the pressure inside the hose  23  decreases. When the pressure inside the hose  23  drops to the predetermined value, the motor  30  is energized because the water depth has dropped too much and the boat is in jeopardy of colliding with land. When the motor  30  is energized, the floating dock  200  is moved along the chain  50  further away from shore until the pressure inside the hose  23  is raised back to acceptable levels according to the adjustable pressure sensor ensuring that the boat is on deeper and safer waters. 
         [0037]    It is also recognized by one skilled in the art that the operator can stand on the floating dock  200  and manually activate the motor  30  to rotate the pulley  40  in a direction toward the shore. This is done when the operator wishes to move the floating dock  200  out of the water and on to the shore. It is customary to attach wheels to the bottom of the floating dock  200 , thus, making it easier to roll the floating dock  200  on to shore for storage or repair. 
         [0038]    An alternative embodiment of the docking apparatus  100  of the present invention connects the timer  10  to a daylight sensor so that the depth sensing system  20  is activated once per day in the morning when daylight appears over the sky. 
         [0039]    Another alternative embodiment of the docking apparatus  100  of the present invention utilizes a depth sensing system  20  that senses the depth of the water with sonar or sonic waves rather than by measuring the pressure inside the hose  23 . 
         [0040]    Another alternative embodiment of the docking apparatus  100  of the present invention replaces the pressure sensor  22  with a mercury reed switch that hangs on the floor of the lake such that when the water level changes, the switch is activated as it becomes suspended vertically above the floor of the lake or lays down flat on the floor of the lake. 
         [0041]    Yet another alternative embodiment of the docking apparatus  100  of the present invention replaces the pressure sensor  22  with a float switch attached to a wheel at the bottom end of a sliding pole and positioned to roll or slide on the floor of the lake. The sliding pole is designed to slide freely in the vertical direction. Thus, as the water depth decreases, the wheel is pushed upward to activate a switch that would then energize the motor. 
         [0042]    Yet another alternative embodiment of the docking apparatus  100  of the present invention uses a microprocessor for more demanding applications and for a higher level of accuracy. In addition, with a microprocessor, the depth sensing system can be configured to activate the motor away from shore when the water level decreases and toward the shore when the water level increases. 
         [0043]    It is understood that the described embodiments of the present invention are illustrative only, and that modifications thereof may occur to those skilled in the art. Accordingly, this invention is not to be regarded as limited to the embodiments disclosed, but to be limited only as defined by the appended claims therein.