US3242895A

US3242895A - Automatic tow rope rewinder

Info

Publication number: US3242895A
Application number: US377649A
Authority: US
Inventors: Hornby James Clifford
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-06-24
Filing date: 1964-06-24
Publication date: 1966-03-29
Anticipated expiration: 1983-03-29

Description

March 29, 1966 J. c. HORNBY 3,242,895

AUTOMATIC TOW ROPE REWINDER Filed June 24, 1964 FIGI FIG.2 3 N '4 la/5W I I I E III" III" L \J I I I II m| IF IIIIIII R I I I I I i 91 l FIG?) I5 I: I I 4| 9 J" 'I II 22 I 36 V L4 I R I I w I F164 -jifi IW United States Patent Filed June 24, 1964, Ser; No. 377,649 6 Claims. Cl. 114-235 This invention relates to a tow rope re-winding device for boats.

As is known, a tow rope device is attached to the rear end of a motor boat and serves to pull a water skier behind the motor boat.

Several such devices have been proposed. For instance, see US. Patent 2,816,310, and Canadian Patent 600,526.

The device of the present invention is not only novel but it embodies features which make the device a very safe one and serve to cure manifest faults and weaknesses in the devices shown in the two patents aforesaid as well as all other devices of which I am aware.

The bad features of the known devices are well known to skiers, the more important of these beingand thus far not overcome or cured-that tow lines often become fouled or tangled when the motor boat changes its direction. It is also well known that the stability of the boat is seriously affected, if not endangered, by the use of the present-day devices.

The most important feature of my invention, and that which lends it so much merit, is that the tow rope, at its forward end, is anchored to and rolled on a drum which rides (slides) axially on a curved rod attached to the rear (transom) of the motor boat to lie in a horizontal plane, the radius of curvature of the rod being such, and the rod being so attached to the transom, that the curved portion or arc of the rod lies behind the engine and the centre of the arc lies in the longitudinal axis of the boat at a distance forwardly of the engine but as close as possible to the vertical axis (axis of rotation) on which the boat horizontally rotates when changing its direction of travel. This feature or principle provides stability to the motor boat at all times, regardless of the change of direction of the boat or of the relative position of the boat and the skier. In other words, the pulling force of the rope is always applied at a point along the longitudinal centre line of the boat and at a point closer amidships than has hitherto been attained by the known water skiing devices.

Thus, the advantages of this device are manifest, particularly in that they promote safety.

Another object or feature of the invention is that it provides a quick releasing mechanism attaching the device to the boat. If at any time it is required that the motor be tilted out of the water, the skiing device of the invention can be released quickly by a sharp blow, say with one hand, applied to each securing point.

In the drawing, wherein like numerals of reference indicate corresponding parts in various figures,

FIGURE 1 is a (more or less diagrammatic) plan view of the device attached to a conventional outboard motordriven water craft, the tow cable being shown as almost completely wound around the drum;

FIGURE 2 is a side elevation of FIGURE 1;

FIGURE 3 is a rear view of the water craft, on an enlarged scale;

FIGURE 4 is a section on line 4-4 in FIGURE 3;

FIGURE 5 is a fragmentary section on line 5-5 in FIGURE 3;

FIGURE 6 is a fragmentary section on line 66 in FIGURE 3; and

FIGURE 7 is a section on line 77 in FIGURE 6.

Referring now by numerals to the drawing B shows a typical boat including a rear flat transom R. Releasably Patented Mar. 29, 1966 mounted on the transom R, say by means to be described later, is a substantially U-shaped supporting guide device D including two parallel side portions or members) and an intermediate curved member 11 of rectangular or any other cross-section except circular. The radius of curvature of the member 11 and the distance between the curved member 11 where it intersects the longitudinal axis of the boat and the transom are such that the centre of the curved member 11 is as close to the vertical axis of rotation of the boat, when carrying its intended load, as may possibly be determined. Such axis is shown as C. In changing its orientation, the boat turns (pivots) on such vertical axis. Preferably, and as seen in FIGURE 1, stops W in the form of washers (say) welded to the guide D limit the sliding movement of the drum N on the guide.

Slidably supported on the guideD, more particularly on its intermediate curved portion or member 11 is a drum on which a cable F is adapted to be wound. To the rear, free end of the cable F is attached a handle 14 which may be of any kind, conventional or otherwise. Attached to the cable F, adjacent to the handle 14 is a stop 15 the function of which will be described later. The cable F, at its inner end, is Operatively anchored to the drum so that the cable may be wound around the drum. The inner end of the cable may be said to be resiliently attached to the drum as will be apparent later.

The drum N may include a one-piece drum proper 30 formed to present opposite flanges 16 and having its side walls 17 formed with aligned apertures 18. Retained within the aligned apertures is a two-piece core 19, in effect forming a non-rotatable supporting shaft on which the drum proper is adapted to rotaterotating in one direction when the cable F is being unwound or'played out, and rotating in the opposite direction to rewind the cable onto the drum.

Operatively connected between the rotatable drum proper 3i and the core 19 are two coil springs 28A, the springs encircling the core and being fixed or anchored at their opposite ends to the drum 30 and to the core 19, respectively. The tension in the springs increases as the drum rotates on the core to play out the cable, the springs operating to rewind the cable on the drum when the pull or tension on the end of the cable is relieved as when the skier has let go of the cable and the speed of the watercraft has been sufficiently reduced.

As already stated, the drum is adapted to slide on the curved portion of the guide D. The two halves 19A 19A of the two-part core 19 are formed with the two co-facing complementary notches (of any shape except circular) defining, when both halves are locked into a core-forming relationship, as clearly seen in FIGURE 6, a channel of cross-section other than circular adapted to slide over the correspondingly cross-sectioned portion 11 of the drum-supporting guide D. Preferably the crosssection should be square.

The inner end of the cable is attached to one end of a rod 23 sliding in one wall (the front wall 31) of a tube 24 housed within a bore 25 formed through the drum. The rod 23 is riveted behind a disc or plunger 26 sliding within the tube. A coil spring 28, encircling the rod 23, is tensioned between the front wall 31 and the disc 26. The front wall 31 is made to a diameter larger than that of the bore 25, so that it serves as a stop determining the longitudinal displacement of the tube rearwardly in the bore 25. A disc 33, of a diameter larger than that of the tube 24 and removably attached to the rear end wall of the tube 24 serves, in conjunction with the front wall 31 of the member 24, to retain the tube in its operative position within the bore, and therefore to lock the tube in operative position. The disc 33 is removably attached to the rear end Wall of the tube 24- as by a nut 46 threaded onto a stud 47 anchored in the rear wall.

The spring 28 serves as a bufier or shock-absorbing member when the cable has been completely played out.

The tube 24 is utilized conveniently to lock the twopiece core 19 in operative position within the drum N by providing on the periphery of the two-piece core a circumferentially extended raised portion or disc formed with a peripheral groove 53 in which the tube 24 is received, as best seen in FIGURE 7.

The cable automatically and gradually unwinds as the boat moves forward and the resistance offered by the water to the forward movement of the skier exceeds the tension in the spring Attached to the core 19 is a cable support in the form of a flat bar 35 slotted as at 36 and held behind the drum as by a pair of arms 37 secured to the core of the drum. Conveniently, the ends of the arms 37 are formed with a pair of fingers 38 secured to the respective halves of the core as by screws 39.

Readily to detach the guide from the transom of the boat, the inner ends of the parallel members 10 of the guide are pivotally attached as by screws 4% to brackets 41. Each such bracket 41 is provided with a slot 42 merging into a circular hole or recess 43 of a diameter larger than the width of the slot 42. The bracket is attached to and suspended from a screw 45 attached to the transom as best seen in FIGURE 4.

Operation As the boat increases its speed (after the motor has, been started), the resistance ofiered by the skier gradually causes the drum to rotateand to continue to rotate until the cable has been let out to its maximum length. However the drum, under the influence of its loaded spring, rewinds the cable when the pull on the cable has been sufficiently decreased as, for example, when the skier lets go of or releases the cable and the speed of the boat has been sufficiently reduced. This constitutes a very important safety feature of my device since once the skier has let go of the cable, and the speed of the boat has been sufficiently reduced, the cable is retrieved to the boat by being automatically rewound onto the drum. The trailing cable is thus prevented from constituting a hazard to the skier or to any one else or to any object in or near the water.

As will be readily appreciated, .the spring 28 acts as a buffer or shock-absorber as when the skis suddenly encounter a wave and a sudden though temporary increase in resistance results.

As already stated, the axis of the cable, when in tension, bisects the longitudinal axis of the boat or is coextensive therewith, according to whether the longitudinal axis'of the boat is at an angle to the longitudinal axis of the tow rope as when the boat is in the. process of negotiating a turn, or the axis of the boat and the axis of the tow rope coincide as when the boat is moving straight ahead.

If the boat is in the process of negotiating a turn, the axis of the tow rope bisects the longitudinal axis of the boat at a point well ahead of the engine and as much as possible and, ideally, bisects the longitudinal axis at the point on which the boat turns when changing its direction of travel.

As will be readily understood, the stop 15 serves to determine the rotation of the drum N in its cable-rewinding operation (clockwise as seen in FIGURE 2) as the stop engages the cable support (flat bar) 35.

What I claim is:

1. In combination with a water craft having a horizontal rail positioned at a distance rearwar-dly of the transom of the water craft, said rail having a non-circular cross-section, a core member mounted on said rail for longitudinal displacement thereon between two selected positions, said core member having a hole therethrough corresponding to the shape of said rail to prevent axial rotation of said core member around said rail, a drum supported on said core member for axial rotation relative thereto, spring means acting between said core member and said drum to tend to maintain the core member and drum in a predetermined rotational relationship, and a cable wound on said drum having an end resiliently-anchored thereto and carrying a handle at its opposite end to be grasped by the skier, said rail including a transversely-disposed curved middle portion the centre of the radius of which lies in the longitudinal axis of the water craft at a distance forwardly of the transom.

2. A combination as in claim 1, wherein a horizontal guide, supported by said drum rearwardly thereof and adjacent thereto, slidably supports said cable.

3. A combination as in claim 1, wherein said rail terminates in oppositely-disposed, parallel members to the ends of which are pivotally attached supporting transomengaging brackets.

4. In combination with'a water craft having a horizontal rail positioned at the rear of said craft, a core member mounted on said rail for longitudinal displacement therealong between two selected positions, said core member including means for preventing axial rotation of said core member around said rail, a drum supported on said core member for axial rotation relative thereto, spring means acting between saidcore member and said drum to tend to maintain the core member and drum in a predetermined rotational relationship, and a cable wound on said drum, said cable being connected to the drum at one end and carrying a handle at its opposite end to be grasped by a skier.

5. A combination as claimed in claim 4 including means resiliently anchoring said one end of the cable to I the drum.

References Cited by the Examiner UNITED STATES PATENTS 12/1959 Force 114-235 X 3/1961 Lang 114-235 MILTON BUCHLER, Primary Examiner. T. M. BLIX, Assistant Examiner.

Claims

1. IN COMBINATION WITH A WATER CRAFT HAVING A HORIZONTAL RAIL POSITIONED AT A DISTANCE REARWARDLY OF THE TRANSOM OF THE WATER CRAFT, SAID RAIL HAVING A NON-CIRCULAR CROSS-SECTION, A CORE MEMBER MOUNTED ON SAID RAIL FOR LONGITUDINAL DISPLACEMENT THEREON BETWEEN TWO SELECTED POSITIONS, SAID CORE MEMBER HAVING A HOLE THERETHROUGH CORRESPONDING TO THE SHAPE OF SAID RAIL TO PREVENT AXIAL ROTATION OF SAID CORE MEMBER AROUND SAID RAIL, A DRUM SUPPORTED ON SAID CORE MEMBER FOR AXIAL ROTATION RELATIVE THERETO, SPRING MEANS ACTING BETWEEN SAID CORE MEMBER AND SAID DRUM TO TEND TO MAINTAIN THE CORE MEMBER AND DRUM IN A PREDETERMINED ROTATIONAL RELATIONSHIP, AND A CABLE WOUND ON SAID DRUM HAVING AN END RESILIENTLY-ANCHORED THERETO AND CARRYING A HANDLE AT ITS OPPOSITE END TO BE GRASPED BY THE SKIER, SAID RAIL INCLUDING A TRANSVERSELY-DISPOSED CURVED MIDDLE PORTION THE CENTRE OF THE RADIUS OF WHICH LIES IN THE LONGITUDINAL AXIS OF THE WATER CRAFT AT A DISTANCE FORWARDLY OF THE TRANSOM.