Water ski training apparatus
United States Patent [191 Gentry [451 Apr. 15,1975  
 1 1 WATER SKI TRAINING APPARATUS [76] Inventor: Don C. Gentry, 1810 Southwest Blvd., Jefferson City, Mo. 65101 [22] Filed: Oct. 5, 1973 [21] Appl. No.: 403,926  
 [52] US. Cl. 9/310 G; 35/29 R [51] Int. Cl. A63c 15/00 [58] Field of Search 9/310 R,31OA,31O B,  
 9/310 G, 310 AA, 310 C, 310 D, 310 E; 114/235 WS; 35/29 A, 29 R; 272/57 B [56] References Cited UNITED STATES PATENTS 3,087,173 4/1963 Meyer 9/310 A 3.352.275 11/1967 Wilson 114/235 WS 3,599,259 8/1971 Shcwmon 9/310 A 3,716,880 2/1973 Sorenson 9/310 G Primary ExaminerTrygve M. Blix Assistant Examiner-Sherman D. Basinger Attorney, Agent, or FirmKoenig, Senninger, Powers and Leavitt 57 ABSTRACT Water ski training apparatus of this invention comprises a generally circular. dish-shaped ski board which enables a novice skier to be pulled by a towboat in water ski fashion and which has a relatively narrow central ski, and a plurality of sections removably secured to the central ski, whereby the sections may be progressively removed from each other and from the central ski until only the central ski remains. This allows a novice skier to make a gradual transition from skiing on a wide ski board to skiing on a narrow central ski as he acquires skills and gains confidence. Also provided on the central ski are movable fins which may be selectively raised or lowered thus providing a skiier learning single ski turnaround maneuvers a transition from a directionally stable slalom ski with fins or rudders on its bottom to an unstable finless trick or banana-peel ski on which turnarounds and other maneuvers are performed.  
 10 Claims, 10 Drawing Figures FATENTEDAFR I SIHTS SHEET 1 0F 3 FIG.3  
 WATER SKI TRAINING APPARATUS BACKGROUND OF THE INVENTION This invention relates to water ski training apparatus which allows a novice skier to make a gradual transition from skiing on a relatively wide circular ski board to skiing on a conventional width ski and from skiing on a conventional slalom ski with fins to a finless trick or banana-peel ski as the beginning skier acquires skill and gains confidence.  
  The process of learning to skillfully ski and to turn around on a single, regulation tournament trick ski has been long and arduous for most skiers. The first step in this process is to learn to ski on a single ski with the feet in a heel-to-toe relationship as opposed to using two skis with the feet side-by-side. The second and more difficult step is learning the single ski turnaround. The principal reason for the added difficulty is the lack of stability of the banana-peel or finless trick ski used to turn around. The lack of a fin permits the skier to break the ski out of its normal track and into a slide, and to complete a 180 turn so that the skiers back is toward the towboat.  
  Several types of water ski training apparatus have been suggested in the past. One type includes a single platform formed by clamping together two or four regular water skis, U.S. Pat. No. 3,626,529. However, such an arrangement does not assist the novice skier in learning to ski or turn around on a single ski. Another type includes an adjustable fin or skeg on a water ski or surfboard, U.S. Pat. Nos. 3,087,173 and 3,516,100. These devices do not allow the skier to retract the fin with his feet in the foot bindings as is required in the turnaround.  
  Conventional water ski disks, while providing a relatively stable platform for the skier, are somewhat difficult to properly tow behind a boat. Because the area of a disk is large as compared to conventional skis, the disk will plane at a much lower boat speed. In many instances the ideal towing speed for a disk is about the transition speed of many tow boats between a displacing and a planing attitude. Many towboats are difficult to control at their transition speeds. If these conventional ski boards are towed at higher speeds, their forward edge may dip into-the water and cause the skier to fall.  
 SUMMARY OF THE INVENTION Among the several objects of this invention may be noted the provision of water ski training apparatus enabling a novice skier to easily and rapidly learn how to ski on a single ski and to perform single ski tricks; the provision of such apparatus allowing the novice skier to make a gradual transition from skiing on a relatively wide, circular ski board to skiing on a relatively narrow single ski; the provision of such apparatus allowing the novice skier to make a gradual transition for skiing with his feet in a side-by-side relationship to skiing with his feet in a heel-to-toe relationship; the provision of such apparatus permitting the skier to control the amount of extension of fins while skiing thereby providing added stability while the skier is attempting single ski turnarounds or while landing after completing a jump on a ski ramp; the provision of such apparatus permitting the skier to control the magnitude of fin extension by movement of his feet in the foot bindings; the provision of such apparatus permitting the skier to independently LII vary the relative extensions of the front and back fins; the provision of such apparatus which may readily be towed by most conventional towboats and which provides a relatively stable platform for the skier at common skiing speeds; and the provision of such apparatus which is reliable, easy to use and economical to manufacture. Other objects and features will be in part apparent and in part pointed out hereinafter.  
  Briefly, water ski training apparatus of this invention comprises a relatively wide, circular ski board for supporting a novice skier so that the skier may be pulled by a towboat in water ski fashion. The ski board includes a relatively narrow central ski, a plurality of removable sections, and means for releasably securing the sections to one another and to the central ski to form the ski board. The releasable means permits the sections to progressively be removed from each other and from the central ski until only the central ski remains thereby allowing the novice skier to make a gradual transition from skiing on the wide ski board to skiing on the narrow central ski as the novice skier acquires skill and gains confidence.  
 BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the water ski training apparatus of this invention planing on the water with a skier in a slaloming position thereon with a front fin in a raised retracted position and with a rear fin in a lowered extended position;  
 FIG. 2 is a plan view of the disk with all slats in place:  
  FIG. 3 is a side elevation view of the apparatus illustrating the front fin raised and the rear fin extended;  
 FIG. 4 is a bottom view of FIG. 2;  
  FIG. 5 is a plan view of the apparatus with the outer three slats removed;  
  FIG. 6 is a plan view of the central ski with all slats removed;  
  FIG. 7 is an enlarged vertical section taken on line 77 of FIG. 2 showing means for releasably joining adjacent slats together;  
 FIG. 8 is an edge view of FIG. 7;  
  FIG. 9 is a plan view of a second embodiment of the apparatus utilizing a number of thin, stiff layers of sheet-like material stacked on top of one another, the layers being removably secured to one another so as to permit the lowermost layers to be progressively removed from one another so as to permit a gradual transition from a ski board to a single ski; and  
  FIG. 10 is a vertical section on line 10-10 of FIG. 9.  
  Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.  
 DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, a first embodiment of a water ski board of the present invention, indicated in its entirety at 1, includes a relatively narrow central ski 3, a plurality of removable sections SA-SF, each sec tion having a pair of slats including a righthand slat SAR and a lefthand slat SAL, etc., on opposite sides of the central ski, and means, as generally indicated at 6, for releasably securing the sections to one another and to the central ski. Slats SAL and SAR are attached directly to the sides of central ski 3 and are relatively narrow and have a curvature and length generally corresponding to the curvature and length of the lateral edges of the central ski. The remaining pairs of slats. attached to the outer lateral edges of a respective adjacent inner slat, gradually increase in both width and degree of curvature and decrease in length so. when assembled, form a generally circular disk. The ski board is generally circular in plan and has, as best shown in FIG. 3. an upturned peripheral edge 7 making the board generally dish-shaped with a generally flat bottom 8. The upturned peripheral edge makes the ski board relatively easy to ride since the upturned edge helps to prevent the front of the board from submerging underneath the surface of the water when the board is towed at normal skiing speeds. The flat bottom gives added stability to the ski board. The various slats and the central ski may be made of any suitable floatable material. such as wood or plastic, whereby the device will float in the event the skier falls while skiing.  
  Various means 6 are employed for releasably securing the slats to each other and to the central ski. As best shown in FIGS. 7 and 8, the relatively narrow inner slats SAL-SBL are releasably joined together by means of bolts B inserted widthwise through holes H in one of the slats (e.g., slat SBL) and threadably engaging an insert I in the inner adjacent slat (e.g., slat SAL) or central ski. The mating lateral edges of the slats and central ski are of tongue-and-grooves construction for added joint strength and for forming a disk of the desired shape. The relatively wide outer slats SDL, SFL and SDR and SFR are releasably joined by batten plates P (see FIG. 2) bolted to the slats. Thus it will be understood that the various slats and the central ski may be securely fastened together to form a rigid platform and that the various slats may easily be removed from one another with the use of only a screwdriver so that the slats may be progressively and readily removed until only the central ski remains.  
  The central ski 3 conforms generally to the shape of a conventional tournament trick ski and has foot bindings 9A,9B for reception ofthe feet of the skier. A plurality of mounting positions are provided for the foot bindings on the central ski and on adjacent slats. This allows the foot bindings to initially be mounted in sideby-side relationship (as shown in phantom in FIG. 2) and to be repositioned in intermediate positions (not shown) until a heel-to-toe relationship (shown in solid lines) is achieved thus providing the beginning skier with a gradual transition to the more difficult single ski foot position. The foot bindings, when in the heel-totoe relation. may be slidable relative to the central ski thereby allowing the skier to move his feet independently along the longitudinal axis of the central ski. Foot bindings 9A,9B are mounted on the central ski or on the various slots by means of clamping screws 11 insertable through longitudinal slats in the foot bindings and received in inserts 13 in the central ski and in the slats, the position ofinserts 13 corresponding to various and rear ends of central ski 3 are slots 14A and 14B through the ski for reception ofa pair of fins or rudders 15A and 158. These fins are pivotally mounted on the central ski and are attached by linkages l7A,l7B to respective adjacent foot bindings 9A and 98 so that by movement of the bindings. the skier may selectively position the fins even while skiing. More particularly, each fin is movable between a lowered extended position in which it is fully extended beneath the ski into the water and a raised retracted position clear of the water. It is to be undersood that the clamping screws 11 for the foot bindings constitute locking means and thus permit fins 15A,15B to be locked in any desired position. Furthermore, it will be understood that with clamping screws 11 loose, the skier may selectively raise or lower fins l5A,l5B while skiing by sliding the foot bindings fore and aft on the central ski.  
  In use, ski board 1 assists the novice skier in several ways. It helps him learn to ski on a single ski by providing a gradual transition from a relatively wide ski board to a relatively narrow single ski as the outermost slats are progressively removed. It aids him in learning to ski with his feet in a heel-to-toe relationship by providing a gradual transition from a side-by-side position for his feet to the heel-to-toe relationship required for single ski skiing. Finally, it helps in learning single ski turnarounds by allowing the beginner to use the back rudder before he enters a turn and then retracting the back rudder before starting the turn, and to again extend the front rudder for stabilizing himself once he attains a backward skiing position, thus avoiding many of the usual falls one undergoes while learning the turnaround on a conventional trick or banana-peel ski.  
  Referring to FIGS. 1, 2, 5 and 6, the novice skier begins learning turnarounds on the ski board I with all sections attached. After several turns and runs practicing skiing forward, side slips at generally right angles to the direction of the towboat, and skiing backwards, he should have acquired sufficient skill and confidence to allow removal of one of the outer pairs of slats 5FR,5FL. With a few runs at each intermediate stage,  
 can learn to execute a skillful turnaround with a minimum number of falls. In this manner the novice skier can learn the art of the single ski turnarounds rapidly and easily because the steps of the learning process are both gradual and progressive.  
  Referring now to FIGS. 9 and 10, a second embodiment of the water ski training apparatus of the present invention, indicated generally at 19, comprises a relatively narrow central ski 21 and a plurality of stacked sections or panels 23A-23D with ski 21 being on top of the stack. Panel 23D, the bottom panel of the stack, is generally circular in plan. The remaining panels are generally elliptical in plan having substantially the same major axis (i.e., length) as the bottom panel and having a minor axis (i.e., width) somewhat less than the adjacent panel therebelow.  
  A pair of foot bindings 27A,27B, similar to bindings 9A,9B, are slidably mounted in heel-to-toe relationship atop central ski 21 for reception of the feet of the skier. Adjacent each end of central ski 21 is a vertical slot 29A.29B for reception of a fin or rudder 31A.31B. respectively, each fin being pivotally mounted on the top of the central ski. It is to be understood that each panel has slots therethrough in alignment with slots 29A,29B. These fins are connected to their respective foot binding by linkages 33A.33B in a manner similar to fins A and 15B of ski board 1 to enable the skier to independently extend and retract the rudders by movement of his feet in a manner as heretofore described.  
  Panels 23A-23D are releasably attached to the central ski by any suitable means. such as by bolting. to provide a rigid structure. It is to be understood that the panels may be quickly and easily removed from one another thereby to progressively allow the skier to reduce the width of the ski board until only the central ski remains.  
  The novice skier may start the process of learning to ski and to do turnarounds on a single ski by using the ski board 19 with all panels attached. After a few runs behind the towboat, the novice may wish to ski on the board with the bottom panel 23D removed. As the skiers skill increases, other panels may be progressively removed until only the central ski remains. As heretofore explained in regard to water ski board 1, a novice skier may at any time gain added stability by selectively lowering or retracting the front or rear fins 3lA.3lB, respectively. Again the learning process is one of gradual and progressive transition.  
  In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.  
  As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.  
 What is claimed is:  
  1. Water ski training apparatus comprising a relatively wide ski board adapted to support a skier so that the skier may be pulled by a towboat in water ski fashion, said ski board comprising:  
 a central ski;  
 a plurality of sections removably secured to said central ski so as to form a dish-shaped ski board generally of the length of and substantially wider than said central ski; and  
 means for releasably securing said sections to one another and to said central ski, said sections being progressively removable from one another and from said central ski to constitute a series of water ski boards of progressively decreasing width as each said section is removed until only the central ski remains thereby allowing the novice skier to make a relatively gradual transition from skiing on said relatively wide ski board to skiing on said relatively narrow central ski as the skier acquires skill and gains confidence.  
 2. Water ski training apparatus as set forth in claim 1 wherein said ski board has an upturned peripheral edge.  
  3. Water ski training apparatus as set forth in claim 1 wherein each of said sections comprises a pair of slats, one of said pair of slats constituting the innermost pair of slats being releasably secured to said central ski,  
 said slats of said innermost pair being on opposite sides of said central ski, the others of said pairs of slats being removably secured to the outer lateral edge ofthe inner adjacent slat, one on each side of said central ski.  
  4. Water ski training apparatus as set forth in claim 1 wherein each of said sections comprises a plurality of panels stacked on top of one another and removably secured relative to one another, one of said panels being generally circular and constituting the bottom panel of said ski board, others of said panels each being generally elliptical in plan and having substantially the same major axis as said bottom panel and having a minor axis somewhat less than the adjacent panel therebelow. and said central ski comprising a top panel of said ski board.  
  5. Water ski training apparatus as set forth in claim 1 wherein said central ski conforms generally to the shape ofa conventional single ski and has a plurality of foot bindings for reception of the feet of the skier, said foot bindings being located at selected positions relative to each other thereby to permit the skier a gradual transition from skiing with his feet side-by-side to skiing with his feet in a heel-to-toe relationship.  
  6. Water ski training apparatus as set forth in claim 1 wherein said central ski has a slot therethrough. and a fin mounted on said ski for movement between an extended position in which said fin extends down through said slot into the water and a retracted position clear of the water. and means operable by the skiers feet for selectively varying the position of said fin to any desired position between its extended and retracted positions while skiing.  
  7. Water ski training apparatus as set forth in claim 6 wherein said central ski has two of said slots therethrough. said slots extending along the longitudinal axis of the ski, one of said slots being adjacent the front of the ski and the other being adjacent the rear of the ski. and a pair of said fins including a front fin pivotally mounted on said ski adjacent said front slot for movement between its extended and retracted positions and a rear fin pivotally mounted on said ski adjacent said rear slot for movement between its extended and retracted positions. each of said fins having means operable by the skiers feet for selectively varying the position of said fin to any desired position between its extended and retracted positions while skiing.  
  8. A water ski training apparatus as set forth in claim 7 further comprising a pair of foot bindings movably mounted on the central ski, said means for varying the position of said fin comprising a link interconnecting each of said fins to an adjacent foot binding whereby movement of said foot bindings relative to the central ski effects movement of said fin interconnected thereto between its extended and retracted positions.  
  9. Water ski training apparatus as set forth in claim 8 further including means for locking each said foot binding to said central ski thereby to lock said respective fin in position corresponding to the position of its respective foot binding.  
  10. Water ski apparatus comprising an elongate ski member having binding means for releasably holding at least one of the skiers feet in position on said ski, a front slot adjacent the forward end of the ski, a rear slot adjacent the rear end of the ski, said slots extending substantially along the longitudinal axis of the ski, a pair of fins including a front fin mounted on the ski adjacent said front slot, a rear fin mounted on the ski adjacent said rear slot, and means-interconnected between said binding means and said fins for selectively moving either of said fins independently of the other between a raised and a lowered position, said means being operable by the skiers feet while skiing.