Safety Release for Water Skiing Tow Line

1. Field of the Invention

The present invention relates to a tow line release device and in particular to a safety release for water skiing tow lines which is adapted for quickly releasing the tow rope upon manual actuation of a trip rope from within the boat.

In many types of water skiing, it is desirable from a safety standpoint to be able to quickly release tension on the tow rope should the skier fall. In trick skiing, for example, one maneuver includes the placement of the skier's foot in the ski rope handle and he is towed without the use of his hands. Should the skier fall while in this position, he is susceptible to serious leg injuries such as pulled muscles, a twisted knee or a broken leg and may ever be dragged under water before the driver of the boat reacts and is able to stop the boat. Aside from the potential for injury, the necessity for the skier to be constantly on guard so that he is able to pull his foot out of the handle or tow strap in the case of a fall reduces his concentration on performing the maneuver.

In addition to accidents resulting because of a trick skier being unable to release his foot from the rope, many accidents occur as a result of the skier becoming entangled in the rope as it is towed from the boat even though he has released the handle. Also, in the case where two or more skiers are being towed at the same time and one skier falls, the loose rope jerks about in the water quite violently and is liable to strike one of the other skiers.

In order to avoid the type of accidents described above, it has been found advantageous to provide for quick release of the tow rope by means of a trip mechanism operated manually from within the boat. One class of prior art devices comprises a pivotally mounted finger which hooks a terminal loop in the ski rope and is retained in engaging position by means of a latch. When the latch is released, tension on the ski rope pulls the finger open thereby releasing the rope. Examples of this type of device include U.S. Pat. Nos. 3,110,331; 3,133,521; 52,385; 1,115,807; 3,205,545 and 2,721,088.

A disadvantage to this type of device is that the finger requires tension on the rope for it to open so that if the ski rope is momentarily slack, as is often the case in trick skiing, the finger will fail to open quickly. Furthermore, the open finger may present an obstacle which can catch the rope and continue to drag the skier. Although the finger in the aforementioned U.S. Pat. No. 2,721,088 is designed such that it drops by gravity to its open position when released, this renders it inherently slow to open in the case of a slack rope. In fact, the rope may even interfere with its opening.

A further example of a prior art tow rope release is shown in U.S. Pat. No. 3,583,355 which discloses a clamp for gripping the free end of the ski rope or bridle. When the release lever is pulled, the jaws of the clamp open thereby releasing the tow rope. Due to the fact that the tow rope is frictionally rather than positively engaged, it may pull loose during skiing, especially if the skier is performing meneuvers which result in a high degree of tension being applied to the rope. Furthermore, clamping of the rope in this manner is likely to result in premature rope wear.

A further drawback to pivoted finger type hitches is that the force exerted by the tow rope on the finger is in a direction which urges it towards its open position. Should the latch mechanism fail, the finger will open thereby releasing the rope and causing the skier to fall. Since this is most likely to occur when maximum tension to the rope is being applied by the skier, as in the case of slalom skiing, the sudden release of tension is more likely to cause injury.

The present invention overcomes the above-discussed disadvantages of the prior art and is an improvement over the release mechanism of prior Application Ser. No. 840,585, filed Oct. 11, 1977, now U.S. Pat. No. 4,173,196, inventors, Edward F. Casad, Thomas R. Casad and Richard E. Jones.

Specifically, the present invention is a safety release for water skiing tow ropes comprising: a body, a mounting bracket for securing the body to a towing boat, a rearwardly opening slot in the body adapted to receive a loop of rope therein, a bolt extending across the slot and closing the same so as to capture the loop of rope received in the slot, and a trip lever connected to the bolt for releasing the bolt out of the slot so that the loop of rope received therein is free to move out of the slot in an unobstructed manner. Quick release of the tow rope loop is provided by a predetermined short arcuate travel of a release arm actuated by a manual pull on the tripcord by a boat occupant. The loop of the tow rope is attached by manual actuation of a manually accessible lever protruding from the top surface of the body. The lever is pivotally attached to a shaft on the body and has a bolt arm which is pivotable from a first position substantially normal to the plane of the slot opening to a second position substantially free of the slot opening. In the second position of the bolt arm, the loop of the tow rope may be inserted in the slot opening, and by manual operation of the lever, the bolt arm caused to move from the second position to engage the loop and to move the loop to the first position. A release arm is manually pivotable about a second pivot mounted on the body abuttably to engage the free end of the bolt arm to hold it in the loop attaching position. The abuttable engagement between the bolt arm and the release arm is along a radius of the second pivot in a towing direction so that the towing force is substantially radial to the second pivot.

The loop of the towing rope is restricted by the slot to engagement with the bolt arm only, and cannot engage the release arm, so that there is no counter-moment exerted by the tow line to the release force moment exerted on the release arm. Further, there is no frictional drag on the release arm by the tow rope loop to interfere with release arm movement in a release direction. Thus, a complete and quick release is obtained in response to substantially the same release force irrespective of the force exerted by the pull of the tow line on the bolt arm. This is a safety feature since release is assured with a given release force and release arm movement. Further, spring biased detent means mounted in the body cooperate with an indentation in the release arm to resiliently hold the release arm in the engaged position until released by manual actuation of the trip cord.

It is an object of the present invention to provide an improved safety release for water skiing tow ropes having a pivotable bolt which completely clears the tow rope-receiving slot upon actuation so that the tow rope is able to clear the slot in an unobstructed manner.

A further object of the present invention is to provide a safety release for water skiing tow ropes wherein the rope engaging bolt is locked both in its open and closed positions by means of an adjustable detent mechanism.

Yet another object of the present invention is to provide an improved safety release for water skiing tow ropes which will release the rope quickly and positively regardless of whether the rope is taut or slack.

A further object of this invention is to provide in the release device of the previous objects a loop positioning bolt arm which, upon manual actuation thereof will engage the loop positioned in the slot.

The above-mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings.

FIG. 1 is a partly sectioned view showing the release mechanism of the present invention mounted to the ski pylon of a towing boat, wherein the mechanism is in the closed position and a tensioned tow rope is engaged thereby;

FIG. 2 is a similar view shown in the tow rope releasing position;

FIG. 3 is a top plan view of the embodiment of FIG. 1 shown in the tow rope attaching position;

FIG. 4 is a similar plan view showing the tow rope in the released position;

FIG. 5 is a section taken substantially at section line 5--5 of FIG. 3; and

FIG. 6 is a rear elevational view showing the tow rope in the attached position.

Referring to the drawings, a pylon 80 is securely mounted in the towing boat and the release mechanism is secured thereto by means of two arcuately shaped clamping elements 82 and 84 and bolts 86 and 88 passing through companion aperture in the pylon 80 and elements 82 and 84. A generally U-shaped body 94 has legs 94a and 94b forwardly extending from rearward bight 94c and are affixed, as by welding, at the ends to bracket 82. A horizontal rearwardly opening slot 96 is formed in body 94 and is dimensioned to receive loop 98a of ski tow rope 98 which is attached to a conventional handle, not shown. Edge beads 96a, 96b are affixed, as by welding, to the upper and lower edges of slot 96, respectively, to present rounded edges which will prevent wear or abrasion of loop 98a.

A pivot pin 100 is rotatably inserted in opposed openings in the legs 94a, 94b above slot 96 and is retained therein by snap washers 102, 104 which fit into circular grooves in the end portions of pin 100. A sleeve 106 is positioned between legs 94a, 94b and rotatably receives pin 100. Sleeve 106 has a length just slightly less than the spacing between the legs 94a, 94b. A lever 108 is welded or otherwise affixed to sleeve 106 and extends upwardly between legs 94a, 94b in manually accessible position. A bolt arm 110 is affixed, as by welding, to sleeve 106 and can be pivoted about pin 100 downwardly into slot 96 as shown. A notch 112 is formed in the lower end of arm 110. Lever 108 may be swung from position 108a, as shown by the dashed lines in FIG. 1 to position 108c wherein it bears against the upper edge of bight 94c which serves as a stop for lever 108 in rope attachment position. An intermediate position 108b is also shown in dashed lines. As is apparent, movement of lever 108 will cause a corresponding movement of arm 110 to corresponding positions shown at 110a, 110b and 110c.

A second sleeve 114, having a length slightly less than the distance between legs 94a and 94b is disposed transversely therebetween and rotatably receives a second pivot pin 116 pivotably inserted into corresponding openings in legs 94a, 94b, pin 116 being retained in position by means of snap washers 118, 119 which fit into circular grooves in the ends of pin 116. A release arm 120 is affixed, as by welding, to sleeve 114 centrally thereof and has a downwardly depending portion 121 provided with an eye 122 in the lower end through which loop 124 of release cord 126 is passed. Lower portion 121 is offset so that cord 126 will clear pylon 80 during swinging movement thereof. As will become apparent, release of rope 98 will occur upon jerking cord 126 toward the left as viewed in FIG. 1.

Arm 120 has an elongated notch 130 on the rearward edge in which is affixed, as by welding, a cylindrical bolt 132 having a forwardly facing notch 134 formed at the upper end thereof which is registrable with notch 112 when arms 110 and 120 are in the position shown in FIG. 1. In this position, the arms 110 and 120 form a straight arm or bar assembly for receiving thereabout the attaching loop 98a. For reasons which will be explained, the engagement of notches 112 and 134 is along a substantially horizontal radius from pin 116. Arm 120 has an upwardly extending portion 136 (FIG. 2), the forward edge 138 thereof being gently curved to abut the rearward facing surface of bracket 82 as a stop when the arm is swung to the position shown in FIG. 2.

Arm portion 136 is provided with a detent hole 140, FIG. 5, which is engaged by detents which include a pair of set screws 142, 144 threaded into legs 94a, 94b, respectively, and retained in an adjusted position by means of lock nuts 146 and 148, respectively. Screws 142 and 144 have inwardly facing spring sockets 150 and 152, for receiving springs 154 and 156 and detent balls 158 and 160, respectively. Balls 158 and 160 engage hole 140 when arm 120 is in the loop-attaching position shown in FIG. 1. Screws 142 and 144 may be adjusted to pre-load springs 150 and 152.

In operation, the loop 98a is inserted in slot 96. The lever 108 is in position 108a and arm 110 is in position 110a so that slot 96 is unobstructed. Arm 108a is then manually moved rearwardly, arm 110 being pivoted downwardly into slot 96 fitting inside of or engaging the forward end of loop 98a and positioning loop 98a in the attachment position shown by the solid lines in FIG. 1. This is an important feature of this invention since loop 98a may be just partially inserted in slot 96 and the rearward pivotable movement of lever 108 will automatically position loop 98a to the fully inserted attachment position. When lever 108 is in position 108c, which is determined by engagement with the upper edge of bight 94c, arm 110 assumes a substantially vertical position.

During positioning of loop 98a, arm 120 is in the position shown in FIG. 2 wherein bolt 132 is below slot 96 providing clearance for the vertical positioning of arm 110, after which arm 120 is rocked counterclockwise about pin 116 until balls 158 and 160 engage detent hole 140 under the force of springs 150 and 152, respectively, thus releasably and resiliently holding arm 120 in the loop-attaching position wherein notches 112 and 134 engage for holding arm 110 in position. Positive limits of rocking movement of arm 120 are provided by the abutment of edge 138 against bracket 82 at both the lower (FIG. 2) and upper portions thereof against bracket 82. In the released position the lower portion of edge 138 abuts bracket 82 and in the loop-attaching or closed position the upper portion engages bracket 82. In the closed position, a towing force on rope 98 forcefully engages the abutting surfaces of notches 112, 134 along a substantially horizontal radius of pivot pin 116, this radius being substantially normal to these abutting surfaces. Thus, the towing force exerts insufficient releasing moment force on release arm 120 to rock or rotate arm 120 to its release position. However, should the skier be in jeopardy, the boat occupant can jerk release cord 126 toward the left as shown in FIG. 1 rotating arm 120 in a clockwise direction against the detent force of balls 158 and 160 moving bolt 132 clear of slot 96 wherein arm 110 can freely pivot in a counterclockwise direction, as viewed in FIGS. 1 and 2. This completely frees slot 96 and permits ready withdrawal of loop 98a therefrom thus preventing the skier from being dragged in the water. It will be appreciated that the release is accomplished by the first portion of arcuate movement of arm 120 of approximately 10.degree. in the disclosed embodiment. Also, arm 120 is not in direct contact with loop 98a which can interfere with a quick and positive release of loop 98a.

The above described structural components are preferably made of high strength stainless steel which will resist corrosion and will provide a durable, strong construction.

While there have been described above the principles of this invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of the invention.