Abstract:
An improved aquatic flotation device particularly useful for dogs. The preferred embodiment of the device includes a relatively flat rectangular platform supported by two floats located on opposite sides of the platform. Each float is connected by two or more straps to the platform. The device is designed so that it can be thrown from shore or from a boat, and land in a manner that the platform is submerged about 1 to 8 inches without a load, and approximately 2 to 15 inches with a load. When a person or a dog attempts to crawl onto the platform, the platform will tip toward the animal to permit the animal to climb aboard the platform. The platform will then stabilize in a level position. The device thus allows for mounting and dismounting with little or no assistance from an outside source.

Description:
FIELD OF INVENTION 
     This invention relates to an aquatic floatation device used to support a load such as a dog. The design of the device facilitates mounting and dismounting with little or no assistance from an outside source. 
     BACKGROUND 
     An object of the present invention is to support a load in a swimming pool, pond, or lake. The device is particularly useful for dogs, but is also appropriate for people and for other animals. 
     Most flotation devices are wearable, graspable or mountable. When the flotation device is intended to support an animal such as a dog, a mountable type of design is often preferable to a wearable or graspable design. 
     A principal disadvantage of mountable flotation devices is the difficulty of mounting the devices from the water. This difficulty is encountered by people and by animals such as dogs. An object of the present invention is to provide a device that permits easy mounting and dismounting from the device without outside assistance. 
     The prior art includes aquatic platforms for rescue and recreation. 
     U.S. Pat No. 5,421,757 issued Jun. 6, 1995, to Donald Basiliere discloses a rescue raft with a buoyant, elongated floor and a pair of parallel air chambers or pontoons on each side with graspable members extending across the floor to facilitate a victim&#39;s entry onto the raft. The platform may also serve as a ladder. An object of the present invention is to allow the floor to be submerged slightly under the water and to tilt slightly for easier mounting. The current invention can be mounted equally from either end. 
     U.S. Pat No. 5,374,211 issued Dec. 20, 1994, to Mitsuo Imazato discloses a lifesaving device including flotation cylinders, where victims may stand on a rope attached to the cylinders. An object of the present invention is to provide a rigid platform supported by flotation means. 
     U.S. Pat No. 4,019,214 issued Apr. 26, 1977, to Stewart Shaw discloses a floating standing platform supported by a pair of unshaped metal handles. The platform is submerged in a body of water and anchored in place to be used as a lifesaving device for swimmers. Shaw notes that the device could be modified by removing the safety belt and anchor chain to create a free floating platform for the possible rescue of pets from a pool. The present invention is an easily collapsible and transportable device which is more suited to occasional use, as well as being left indefinitely in the water. 
     U.S. Pat No. 4,662,852 issued May 5, 1987, to Stephen Schneider discloses a floating reclining lounge which can be adjusted in the aquatic environment. The present invention is two floatation or pontoons with a floor which is submerged under water and tilts for easy mounting and dismounting. 
     Another object of the present invention is to provide a floatation device which is easy to deploy from shore or from a boat. 
     Another object of the current invention is to provide a floatation device which is light weight, portable and collapsible to provide convenient storage. 
     Another object of the current invention is to be adjustable to accommodate various size loads. 
     Another object of the current invention is to be uncomplicated and inexpensive to produce. 
     In the preferred embodiment, the floatation device is comprised of two elongated buoyant blocks or air chambers. These blocks or air chambers are constructed from closed cell plastic foam such as polyethylene, polyurethane or vinyl. These blocks or air chambers are connected to the parallel sides of a rectangular platform by flexible, adjustable straps. This platform is non-buoyant and will not float without external support, and it has holes to allow for faster submersion and to provide a traction surface for easy mount and dismount by the animal. The platform is constructed from molded plastic, although metal, fiberglass reinforced plastic or a combination of materials may be used. The platform contains molded in hand holes for transport, and its floor is supported by a relatively ridged perimeter frame that has some flexibility. 
     The connecting devices are preferably composed of a cloth or nylon web strap with a buckle for adjusting strap length. One end of the strap connector is attached to the bottom of the floatation device, preferably at its longitudinal center-line. The other end of strap connector is attached to the platform by looping the strap loosely through slotted hole and threading it back through the adjusting buckle. This attachment provides a means to adjust the distance between platform and floats. Furthermore, the straps function as flexible connectors to allow the floats to be placed against the platform to reduce the size of the raft for easier transportation and storage. In addition, the end of the strap loops through slotted hole in a manner which allows the float to rotate around the platform 360 degrees. 
     The two floats are elongated buoyant blocks or air chamber which are preferably symmetric and of similar shape but are longer than they are wide. The bottom side of the floats are preferably less buoyant than the top side. This differential is preferably accomplished by creating a groove longitudinally along the bottom of the float material. The groove creates dual protrusions on either side of groove. The protrusions extend the length of the float. The protrusion aids in stabilizing the floats in an upright position. The floats are preferably longer than the side of the platform to which they are attached, this serves to prevent the raft from tipping too far when being mounted and while in use. 
     The floatation is designed to control the rate and amount of submergibility. The groove allows the raft to initially submerge and tip rapidly and easily for mounting. After mounting, the floats submerge beyond the top of groove. This allows for a reduced rate of submergibility and a greater liquid displacement, which supports the load. The ends of the floats are long enough to extend several inches beyond both the front and back of the platform. This extended float prevents the raft from being overturned as the raft is being mounted. The ends of the floats are preferably angled or slanted about 15 degrees to aid in quick and easy submergibility. 
     The floatation device may be constructed with rails, connecting straps, anchoring tabs and attachment slots. 
     SUMMARY 
     The invention is an improved aquatic flotation device comprised of at least two flotation means or pontoons, which are attached to two parallel sides of a relatively flat and rigid platform. The flotation means are attached by at least one attaching device such as an adjustable strap connecting each pontoon to the platform. The platform is of a design and material that will allow the platform to be non-buoyant when placed in water. The connecting members are configured to allow the platform to be supported in a submerged position ranging from the surface of the water to approximately eight inches below and parallel to the surface of the water. The platform and connecting devices maintain a spacing of the floatation on two parallel sides of the platform forming two openings at the ends of the platform. In the preferred embodiment, the device is designed to submerge in water at different rates—relatively quickly initially when the platform is empty and more slowly once the load is in place on the platform. This varying submergibility is accomplished with the shape, size and mounting of the floats. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other objects and advantages of the present invention are set forth below and further made clear by reference to the drawings, wherein: 
     FIG. 1 is a perspective view of the platform, flotation means, and connection means 
     FIG. 2 is an end view of the flotation means. 
     FIG. 3 is a side view of the flotation means and detail of embedded member. 
     FIG. 4 is a top view of the flotation means. 
     FIG. 5 is perspective view of the platform, flotation means, and connection means for a second embodiment featuring a foldable platform. 
     FIG. 6 is a detail of the hinge and latching device. 
     FIG. 7 is a detail of the adjustable, hinged attaching member for the second embodiment. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to FIG. 1, which is a perspective view of the preferred embodiment of the flotation device  10 , the device is comprised of two elongated buoyant blocks or air chambers  300  which are preferably symmetric. The floats  300  are preferably longer than they are wide. The bottom portion of the floats are less buoyant than the top. Preferably, the construction of the floats will be from a closed plastic cell, or foam such as polyethylene, polyurethane, vinyl, or other foam material. The floats are connected to parallel sides of a rectangular platform  100  by flexible, adjustable, strap connectors  200 . The platform  100  is constructed of a non-buoyant material, so that when it is placed in water, it does not float with out external support. The platform  100  is perforated with holes  130 , having a preferred diameter of approximately 0.5 inch. The holes allow for faster submersion of the platform, and supply a traction surface on the platform to assist in mounting the device. A preferred material for the platform is an injection molded plastic, although metal, fiberglass reinforced plastic, or a combination of suitable materials may be used. A plurality of hand holds  120  are integral to the platform to permit carrying the device. 
     A connection means such as cloth or nylon web straps  200  are used to support the platform. An adjustable buckle  210  is preferably used as means of adjusting the length of the connection means and the depth of the empty platform. The connector straps are perferably identically perforated to permit the straps to be adjustable in equal increments in order to keep the platform level. One end of each strap connector is attached to the bottom of a float  300  near the longitudinal center line of the float  300 . The other end of strap connector is attached to the platform, The preferred platform connection method is to loop each strap loosely through a slotted hole  150  in the platform, and thread it back through the adjusting buckle  210 . The buckle may then be used to adjust the distance between platform  100  and the floats  300 . The straps also function as hinge or flexible connectors to allow the floats to be placed against the platform to reduce the size of the raft for easier transportation and storage. When the strap is looped through a platform slot, the float is permitted to rotate around the platform so that the device may be thrown into the water without regard to the position of the floats—the platform will be supported whether it lands face up or face down. 
     The floats  300  are preferably symmetric and are preferably longer than they are wide. The bottom portion of a float is made relatively less buoyant than the top side by preferable creating a groove  320  longitudinally along the bottom of the float material so that the bottom portion of the float contains less flotation material than the top portion. Other means such as tapering the floats may be used to achieve this differential flotation. In one embodiment, the differential buoyancy between the top and bottom of the float is achieved by providing floats that resemble a large dog biscuit when the floats are stacked bottom edge to bottom edge for packaging the device. 
     Referring now to FIG. 2, which is an end view of the preferred flotation means, the groove  320  creates duel protrusions  360  on either side of groove. The protrusions  360  extend for the length of the float  300 . The protrusions aid in stabilizing the floats  300  in an upright position. The floats  300  are preferably longer than the side of the platform to which they are attached. Extending the floats  300  beyond the ends of the platform  100  serves to prevent the raft from tipping to far when being mounted or while in use. 
     The floatation means  300  are designed to control the rate and amount of submergence of the platform. This control is accomplished by the groove, which allows the raft to initially submerge and tip rapidly and easily for mounting. After mounting, the floats submerge beyond the top of groove  320  allowing for a reduced rate of submergibility and a greater water displacement which supports the load. The ends of the float are long enough to extend several inches beyond both ends of the platform. This extended float prevents the raft from being overturned as the raft is being mounted. The ends of the floats  350  are preferably angled approximately 15 degrees to aid in smoothing the submergence. 
     Referring to FIG. 3, FIG.  4  and FIG. 5, the floats are preferably fabricated from a closed cell foam flotation material. Preferably, the floats are molded with an embedded insert  370 . The insert may be of an injection molded plastic. The insert includes a rail  371 , and arms  372  perpendicular to the rail. There is an arm for each connecting strap, and each arm preferably extends into a groove on the float. Anchoring tabs  374  are provided for each arm. Attachment slots  373  are provided at the free end of arms  372 . The anchor arms are orientated to project from approximately the center line on the bottom side of the floats to allow each connecting strap  200  to thread through a slot  373 . The anchor tabs  374  are included to prevent the embedded insert  370  from being loosened or removed from its embedded position in the float. Perforations  375  are included in the anchoring tabs, arms, and rails to allow the float material to form through the embedded insert  370 , thereby improving the attachment or anchoring strength of the insert  370  inside the float  300 . 
     The preferred embodiment, which is suitable for medium to large dogs has a platform approximately 28 inches long, 24 inches wide, and ½ to ¾ inches thick. The corresponding float size is approximately 36 inches long, 7 inches high, and 4.5 inches thick. 
     In the following explanation, reference is made to a dog as user. The user may also be a human adult, child, or infant, disabled or not, or other animal. Any of these users would mount the raft in a similar manner. The mounting procedure is found to be a series of natural movements. 
     The raft is deployed by placing it or throwing it onto a body of water. The design of the raft allows it to automatically assume the desired position. The platform will typically sink a few inches below the water surface, and will be held at the proper depth by the floats and the straps. The preferred platform design has two open ends so that the user may approach the raft from either end. 
     Because of the submerged position of the platform, the dog is able to easily place a front paw on the end of the platform closest to it. As the dog forces its weight on the platform, the end of the platform closest to the dog begins to submerge as the floats support part of the weight of the dog. As the dog moves forward in mounting the platform, the platform travels toward and under the dog. 
     As the dog continues to travel forward, the raft end submerges further and supports more of the dog&#39;s weight. As the end of the raft closest to the dog submerges, the end of the floats submerge and move under the dog at a downward angle with respect to the surface of the water. This additional submergence allows the dog to place it&#39;s hind legs on the platform, thereby allowing the dog to propel itself forward and up the platform. As the dog moves forward, it continues to pull the raft back under itself. 
     As the dog brings himself to the center of the raft, the raft is brought back to a stable position approximately parallel to the surface of the water. The backward motion of the raft diminishes. 
     When the dog has completely mounted the raft the platform, the raft will automatically stabilize. The raft platform will remain relatively parallel to the water surface. The raft platform will submerge several inches under the dog&#39;s weight with the floats submerging proportionally. The raft is then at rest, and so is the dog. The dog is free to move about the platform area. Dogs will typically sit or stand on the platform. Although the raft will tip slightly as the dog moves or adjusts its position, the raft will not roll over and will remain stabile enough for the dog to feel secure. 
     Some dogs may exit the raft in an easy swimming dismount. Some dogs will leap from the raft. In the later case the inherent drag of the raft prevents it from being propelled too rapidly or forcefully in the opposite direction. 
     ALTERNATE EMBODIMENT-PLATFORM FRAME 
     Referring again to FIG. 1, as an alternative to a very rigid platform, a rigid perimeter frame  160  may be used as a support for the platform floor. 
     ALTERNATE EMBODIMENT-HINGED SUPPORTS 
     Referring now to FIG. 5, the figure illustrates an alternate embodiment in which the platform is constructed of a hollow tubular frame. The frame is preferably constructed of a light-weight and non-corroding material such as aluminum or plastic. The frame  410  may be formed by bending two lengths of tubing to form open ended rectangular sections, where each section supports a portion of the platform. The end sections of the frame are joined together by two hinge mechanisms  400  shown in detail in FIG.  6 . The hinges allow the frame  410  to be folded in half for transport and storage. A latching device shown in detail in FIG. 7 provides a means to latch the frame  410  in a unfolded or open position and prevents the frame from folding when latched and in use. In this embodiment, a strong fabric  460 , such as polyester or vinyl, may form the floor of the raft platform. The fabric  460  is stretched taught over the frame  400  when the raft is in the open and latched position. Cut out sections  451  are provided to prevent the fabric  460  from binding in the hinge and to allow access to the latch. Furthermore, cut outs  451  aid in reliving the tension in the fabric  460  when the platform is being folded. Cut outs  450  at each corner of the fabric  460  are provided to prevent the fabric  460  from bunching in the corners. Another function of the cut outs  450  is to provide handhold in the platform. An additional function of the cutouts  450  is to provide a means for the water to pass through the platform and there by aid in the submersion of the platform. Cut outs  430  in the fabric  460  on each side of the platform allows access to the tubular frame  410  for the attachment of the hinged float adjusters. An additional function of cut outs  430  is to aid in the submersion of the platform. 
     FIG. 7 shows the float attachment and the hinged adjuster comprised of two perforated adjuster strips  540  and  550 , adjuster latching collar  570  and hinging frame attachment  530 . These parts  540 ,  550 ,  370 ,  540 ,  530  may be made from the same injection molded plastic. The perforated adjusting strip  550  is attached to an embedded anchoring means as described in the first embodiment. Each arm may be lengthened to extended several inches (4 to 6 inches) beyond the bottom of float  200  to form strip  550 . Equally spaced perforations  580  are provided for the adjustment device. Strip  540  is formed into a loop  530  on one end. Loop  530  is of a diameter which will fit loosely around the frame tube  410  allowing loop  530  to rotate freely around frame tube  410 . The strip  540  is perforated with equally spaced holes  580  to match the holes in part  550 . Strip  540  and strip  550  are joined as illustrated in FIG. 9 by a movable adjuster  570  which contains a pin that corresponds in size with the perforations in strip  540  and  550 . 
     ALTERNATE EMBODIMENT—RESCUE DEVICE 
     An alternative embodiment of this invention is useful as a rescue device during flood disasters for large animals such as horses, cattle, or sheep. The raft is comprised of a platform  100  and two bouyant chambers  300  configured as in the first and second embodiments. The platform  100  of the raft is approximately 6 feet wide by 8 feet long. The platform is comprised of a perimeter frame  410  made from steel, aluminum, wood or other suitable material. Attached to the frame to form the floor of the raft is a flat metal sheet such as expanded steel or perforated aluminum. Alternately, a perforated wood or plywood material could also be used. The perforations should be approximately one inch in diameter. The flotation members  300  are inflatable air chambers constructed of a waterproof and air-tight fabric such as rubber coated canvas. The air chambers are in a tear drop shape when viewed from the end with the small end of the tear drop as the bottom side. The air chambers  300  measure approx 10 ½ feet long by 1 foot in diameter. The connecting members are a flexible cord, chain, cable, or nylon web strap  210 . In this embodiment a flexible cord or strap is used to secure the air chamber  300  to the attaching member  210 . A series of D-rings are secured to the lowest portion of float. Through the D-ring is secured one end of a strap connector. The other end of the strap is secured to the platform perimeter frame. The length of the strap can be changed to change the distance between the platform and air chambers. This embodiment can be attached to an anchor or moored to a permanent structure allowing the user to remain secure until rescued or until the flood waters recede sufficiently. 
     All embodiments scan be attached to a boat or structure as an aid in exiting the water.