US3604388A

US3604388A - Releasable water ski towing device

Info

Publication number: US3604388A
Application number: US858685A
Authority: US
Inventors: Russell A Brown; Paul W Brown
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-09-17
Filing date: 1969-09-17
Publication date: 1971-09-14
Anticipated expiration: 1988-09-14

Abstract

A towing device for towing water skis in which the ski or skis are removably clamped, the device being retained in place when the ski or skis are in a static condition, by pressure exerted by a pair of spring mechanisms, clamping the device to the ski or skis. Further clamping force is applied by pressure on the handle of the towing device when the skis are initially towed, the device being releasable when the pressure is released from the handle momentarily, for a sufficient length of time to permit the towing force applied to the towrope to overcome the pressure exerted by the spring mechanisms on the device and thereby allowing the towrope to strip the towing device off the end of the ski or skis. The device is made of buoyant material and floats on the surface of the water.

Description

United States Patent inventors Rusell A. Brown 715 Yale Place. S.W., Atlanta, Ga. 30315: Paul W. Brown, 1831 Forrest Street,

Memphis, Tenn. 38112 Appl. No. 858,685 Filed Sept. 17, 1969 Patented Sept. 14, 1971 RELEASABLE WATER SKI TOWING DEVICE 17 Claims, 7 Drawing Figs.

Primary Examiner-Trygve M. Blix Attorney-Newton. Hopkins & Ormsby ABSTRACT: A towing device for towing water skis in which the ski or skis are removably clamped, the device being retained in place when the ski or skis are in a static condition, by pressure exerted by a pair of spring mechanisms, clamping the device to the ski or skis. Further clamping force is applied by pressure on the handle of the towing device when the skis are initially towed, the device being releasable when the pressure is released from the handle momentarily, for a sufficient length of time to permit the towing force applied to the towrope to overcome the pressure exerted by the spring mechanisms on the device and thereby allowing the towrope to strip the towing device off the end of the ski or skis. The device is made of buoyant material and floats on the surface of the water.

PATENTEU SEP] 4 l97| 3,604,388

sum 2 or 2 RELEASABLE WATER SKI TOWING DEVICE BRIEF SUMMARY OF THE INVENTION This invention relates to a towing device for towing skis and is more particularly concerned with a device which yieldably clamps the tow end of one or two skis so that a towing force may be applied to the skis until sufficient speed is achieved for the towing device to be released, at which time the towing force is applied to the handle held by the skier.

In the past, towing devices have been devised. U.S. Pat. Nos. 3,125,060; 2,946,220, and 2,938,220 are examples of such towing devices. The prior art towing devices, however, have been quite bulky and complicated and have been difficult to engage and disengage from the skis.

Briefly described, the present invention which obviates the difficulties described above, includes a clamping mechanism of suitable width to extend across one or two skis, as the case may be. In one embodiment, the clamping mechanism includes a pair of crossbars which are disposed parallel to each other. The ends of each crossbar are provided with parallel outwardly extending arms which are pivotally connected respectively by pivot pins so as to enable each of the crossbars to be swung in an arcuate path toward and away from each other. One pair of arms, connected to one of the crossbars, extends aft from their crossbar beyond the pivot pin and are provided at their outer end with holes which receive the control ropes of the towing device. The other ends of the control ropes are connected to a handle, the ropes being an appropriate length to fit a skier. Fingers pivotally connected to the pivot pins and to a bridle and towrope transfer the towing force to the device. The two crossbars are yieldably urged toward each other by a pair of spring mechanisms while stops on the longer arms prevent any more than limited movement of the two crossbars away from each other.

By this arrangement, the front-end portions of a ski or skis can be inserted between the two crossbars, the crossbar carried by the small or shorter arms being disposed on the bottom of the skis whereby a clamping action is exerted when the outer ends of the longer arms are urged upwardly and aft by the handle. Upon release of this pressure, and, provided there is force applied forwardly on the clamping mechanism by the towrope, the clamping mechanism will be stripped off the ski.

The second embodiment includes a pair of crossbars which are disposed parallel to each other. The ends of each crossbar are provided with parallel outwardly extending arms which are pivotally connected respectively by pivot pins so as to enable each of the crossbars to be swung in an arcuate path toward and away from each other. One pair of arms, connected to one of the crossbars, extends aft from pivot pins toward and beyond their crossbar and are provided at their outer end with holes which receive the control ropes of the towing device. The other ends of the control ropes are connected to a handle, the ropes being an appropriate length to fit a skier. The two crossbars are yieldably urged toward each other by a pair of spring mechanisms while the camming action of this embodiment limits the amount of movement of the two crossbars away from each other. At the pivot pins are a pair of fingers which are connected to ends of a bridle of the towrope.

By this arrangement, the front-end portions of a ski or skis can be inserted between the two crossbars, the crossbar carried by the small arms or shorter arms being disposed on the top of the skis whereby a clamping action is exerted by the spring mechanisms and further clamping action is exerted when the outer ends of the longer arms are urged upwardly and aft by the handle. Upon release of handle pressure, and provided there is force applied forwardly on the clamping mechanism by the towrope, the clamping mechanism will be stripped off the ski or skis.

DESCRIPTION OF THE DRAWING FIG. 1 is a side elevational view of a person using a slalom water ski, the water ski being towed by the towing device of the present invention;

FIG. 2 is a perspective view of the towing device disclosed in FIG. 1; it

FIG. 3 is a vertical sectional view on an enlarged scale showing the clamping mechanism of the towing device clamping the ski, which is illustrated in broken lines;

FIG. 3A is a view similar to FIG. 3 showing a modification;

FIG. 4 is an enlarged fragmentary plan view of one portion of the towing device disclosed in FIG. 1;

FIG. 5 is a plan view of the second embodiment of the present invention; and

FIG. 6 is a vertical sectional view of the device as illustrated in FIG. 5.

DETAILED DESCRIPTION OF THE INVENTION First Embodiment Referring now in detail to the first embodiment chosen for the purpose of illustrating the present invention, numerals l0 and 20 refer respectively to the two parallel complementary tubular clamping bars or crossbars of the ski-clamping mechanism. The front portion of a slalom water ski 30 is to be disposed between these two

bars

10 and 20 for initial towing and for subsequent release.

The

bars

10 and 20 in the present embodiment are of a length slightly longer than the width of the conventional slalom ski 30; however, it will be understood by those skilled in the art that, by making the

bars

10 and 20 of a length to receive, simultaneously, both skis of a conventional pair of skis (not shown) a skier can be towed wearing these skis and both skis can be released, when desired. In such an arrangement, the

bars

10 and 20 will act to hold both skis in proper alignment as well as to provide for the towing action.

In more detail, the

bars

10 and 20 are each lightweight, hollow, rigid tubular members which, if desired, can be filled with a foamed plastic. The purpose, of course, is to provide buoyancy as that the clamping mechanism will float. However, it will be understood by those skilled in the art that

clamping bars

10 and 20 could be made of other rigid buoyant materials, other than that described above, and not necessarily hollow, and also could be filled with other buoyant materials in place of foamed plastic. The hollow tubular members could be sealed airtight to provide buoyancy.

The peripheries of the

bars

10 and 20 must frictionally engage and hold the ski 30 or skis, as the case may be, and yet neither destroy nor mar the lacquered surfaces. To accomplish this; we have coated these peripheries with cork I], even though other yieldable materials, such as plastics, could be used for this coating 11. Cork 11 serves to increase the buoyancy of the clamping mechanism and increase the friction between the bars and ski, while at the same time, providing the protective surface.

The ends of the

bars

10 and 20 are crimped shut to provide flat flanges or

arms

12a, 12b, and 22a, 22b, these arms being bent perpendicular to the axes of

bars

10 and 20 to complete a pair of U-shaped yokes. Bar 20 is shorter than bar 10 so that arm 22a is disposed inwardly of arm 12a and arm 22b is disposed inwardly of arm 12b.

Arms

12a, 12b, 22a, 22b are parallel to each other and perpendicular to the axes of

bars

10 and 20. The outer ends of

arms

12a, 22a are overlapped as the ends of arms 12b, 22b, and these overlapped portions are pivotally pinned together by pivot pins 13a, 13b. When viewed along a radial plane, the common axes of pins 13a, 1312, form the apex of an isosceles triangle defined by the three axes, as shown at ABC in FIG. 3.

By the arrangement heretofore described, the

bars

10 and 20 may swing about the axis of pins 13a, 13b, toward and away from each other, while their parallelism is maintained. The movement away from each other, however, is limited by a pair of inwardly projecting stop pins P,,, P mounted on the inside surfaces of

extension plates

16a, 16b, which are riveted to inside surfaces of arms 12a and 12b for engagement with the edges of arms 22a and 22b, respectively.

it will be understood by those skilled in the art that by making arms 22a and 22b longer to form an obtuse triangle as shown in FIG. 3A the effect is to allow the device to be stripped off the ski easier but with more handle pressure required to clamp the device on the ski or skis. Shortening arms 22a, 22b, to form an acute triangle has the opposite effects. The isosceles triangle is shown in this embodiment.

Coiled springs 14a and 14b, anchored by anchor pins a and 15b to extension plates 16a, 1617, which are riveted to inside surfaces of arms 12a and 12b, are connected to arms 22a and 22b for urging the inner yoke against the outer yoke. Therefore, bar 10 is yieldably urged against bar by springs 14a, 14b.

The arms 12a and 12b are extended aft from crossbar 10 toward and beyond the pivot pins 13a, 13b. In the present embodiment, this is accomplished by a pair of

arm extension plates

16a, 16b, the outer ends of which are secured by rivets 17 to arms 12a, 12b. The ends of

extension plates

16a, 16b, are provided with holes 18a, 18b, to provide a means by which the ends of flexible ropes 19a, 19b are secured to the ends of a transverse handle 25.

Pivotally carried by pivot pins 13a, 13b, outwardly of arms 12a, 12b, are flat, generally rectangular towing lugs 21a, 21b. The distal ends of the lugs 21a, 21b, are provided with holes H H,,, through which the ends of a bridle rope 23 is secured, the bridle rope 23 being connected to one end of a towrope 24. The other end or distal end of towrope 24, of course, is adapted to be connected to the back of a suitable ski boat or other suitable towing means (not shown) which pulls the skier 3 1.

Second Embodiment The second embodiment is quite similar to the preceding embodiment in that it includes a pair of

crossbars l

10 and 120 which are lightweight tubular members which can be filled with foamed plastic or other flotation material. The periphery of these bars is covered with cork material and the bars are crimped shut to provide the flat flanges or arms 112a, l12b and 1220, and 122b. The ends of the arms 112a, 112b, 1220, 122b, are joined by pivot pins 1 13a and 11317.

According to the present invention, a coil spring 114a is wrapped around the pivot pin 113a twice, the coil spring 114a being disposed between the arms 1 12a and 122a. The ends of the spring project rearwardly and are contained within holes 115a and 1 15b in the arms 1 12a and 122a, respectively. in like manner, a coil spring 1141) is provided around the pivot pin 113b between the arms l12b and 122b, the ends of the spring 1 14b projecting through holes 1 150 and 115d in the arms 112b and 1221:. Thus, the

cylindrical crossbars

110 and 120 are urged together by springs 114a, 114b but can be yieldably moved apart, moving in an arcuate path about the pivot pins 113a and ll3b.

in the present embodiment, the extension plates or arms 116a and 116!) form lever arms which are disposed outwardly of and fixed flat against the outer surfaces of arms 112a and 112b, respectively. Thus the plates 116a, 116b and the crossbar 110 forms an l-l-shape, the pivot pins 113a and 1 13b being at one extremity of the arms 116a, 11611 and the holes 1181.1, 1 1817 being at the other extremity thereof.

The towrope 124 is attached by the bridle 123 to the towing lugs 1210, 121b, the bridle 123 being fixed through. the holes H and H in the towing lugs 121a, 121b, respectively. The other ends of the towing lugs 121a, l2lb are carried by the pivot pins 1130, 1 13b, outwardly ofarms 1 16a, 1 16b.

The handle 125 is similar to the handle 25 of the preceding embodiment and is attached by equal-length flexible ropes 119a, 119b, through holes 118a, 118b, to the free ends of the plates 116a, 116b. Thus, with the ropes 119a, 119k extended, the handle 125 is parallel to bars 1 10 and 120.

Operation From the foregoing description, the operation of the present invention should be apparent. The distal end of towrope 24 is secured to the ski boat (not shown). The forward end portion of the slalom ski 30 is inserted between the two opposed cross bars 10 and 20.

While our clamping mechanisms disclosed herein are capable of operation in other fashions, it is preferable, when installing the clamping mechanism of FIGS. l-4, to dispose the mechanism with the

arms

12a, 12b, 22a, 22b, projecting rearwardly. Also, the bar 20 should be beneath the ski 30 and the bar 10 on top of ski 30. Both bars 10 and 20 project transversely across the ski 30.

The springs 14a, 14b, cause the

bars

10 and 20 to be urged continuously toward each other to clamp the ski 30 therebetween. Once installed, the clamping mechanism remains in place on the ski 30 due to the clamping force exerted between the two

bars

10 and 20, as a result of the spring tension of springs 14a, 14b. However, this spring-clamping force is a minimal clamping force to maintain the clamping mechanism in place under essentially static conditions. This force alone is not sufficient to prevent the clamping mechanism to be stripped from the ski 30 when the boat is moving at skiing speed.

When the skier 31 has fitted the ski 30 to his feet and holds the handle 25, he pulls upwardly and rearwardly on the handle 25, thereby pivoting

extensions

16a, 16b in an upward direction. This causes the two

bars

10 and 20 to be urged apart due to the arrested conditions of the ski 30, until the arms 22:: and 22b strike stop pins P,,, P,,. Further urging of handle 25 therefore forces bar 10 and bar 20 firmly against their associated surfaces of ski 30. Hence, so long as handle 25 maintains the ropes 19a, 19b, taut, the clamping mechanism will be essentially locked in its rotated position of maximum clamping action and will frictionally hold the ski 30 for towing.

it will be understood by those skilled in the art that the natural tendency of the skier 31 is to pull back firmly on the handle 25 and thus pivot the clamping mechanism to its locked position or position of maximum clamping action. In such a position the skier may be pulled by rope 24 from a dead in the water condition to a planing condition in which the ski 30 is skimming over the surface of the water, traveling at skiing speed, and skier 31 is in a substantially upright position,

When skiing speed is attained, the skier 31 relaxes momentarily the holding of ropes 19a, 19b, in a taut condition. This reduces the clamping mechanism force exerted by the mechanism and enables towrope 24 to strip the clamping mechanism from the ski 30 so that towing action is transmitted directly from the boat, via rope 24, the clamping mechanism and ropes 19a, 19b, to the handle 25 and to skier 31.

The device of F I65. 5 and 6, the second embodiment of our invention, is used in very much the same manner as the preceding embodiment. The crossbar 110, however, is placed on the bottom of the ski 130 while the crossbar 120 is disposed on top of the ski 130. When the ski 130 is static in the water, i.e., when no appreciable pull is exerted on the towing device by rope 124, the spring tension of springs 114a, 114b, is sufficient to maintain the mechanism clamped transversely on the ski 130. When a force is applied to the handle 125, as when a skier pulls back and upward on the handle 125, the device is locked in place with a camming action which tends to urge the two crossbars and apart and the arms 112a, 1121: to a perpendicular position with respect to the arms 122a, 1221); however the force tends to rotate the device in a counterclockwise direction (as illustrated in FIG. 6) and is sufficient to lock the device on the end portion of the ski so that the ski 130 and its rider may be towed through the water sufficiently fast for the skier to go from the static condition to a planing condition.

When the ski 130 is planing, the skier is in an upright position on the ski, relaxation of the tension on ropes 119a, 119b, will reduce the clamping action of the mechanism and permit the bridle 123 to urge or strip the mechanism off ski 130.

It will be understood by those skilled in the art that when utilizing the clamping mechanisms of the present invention for a pair of skis, the clamping mechanism action is substantially the same with the added advantage that the mechanism will maintain the toe portion of the skis adjacent each other with the skis tending to trail therebehind, in parallel relationship. Therefore, using the device for a pair of skis aids a novice skier, materially, in getting up on the two skis.

What is claimed as the invention:

1. A towing device for water ski comprising:

a pair of crossmembers movable toward and away from each other for clamping a ski therebetween;

a towrope attached to said crossmembers; and

means for moving said crossmembers relative to each other into a clamping engagement with the ski during an initial period when said ski is to be pulled by said rope and for thereafter releasing said crossmembers sufficiently for the device to be stripped off the end of the ski by said towrope.

2. The towing device claimed in claim 1 wherein said means includes arms pivotally connected together and connected to the ends of said crossmembers.

3. The towing device claimed in claim 1 wherein said means includes a handle for urging the members into a position for clamping the ski therebetween.

4. The towing device claimed in claim 1 wherein said members are parallel bars longer than the width of a pair of skis.

5. The towing device claimed in claim 1 wherein said means includes:

a first pair of arms extending radially from the ends of said members;

a second pair of arms extending radially from the other of said members;

first pivot means for pivotally connecting one arm of said first pair of arms to one arm of said second pair of arms; second pivot means for connecting the other of said one pair of arms to the other of said second pair of arms; and said first and second pivot means being aligned for permitting swinging movement of said members with respect to each other while maintaining said members in parallel relationship.

6. The towing device claimed in claim 5 wherein said firstmentioned means includes a handle for urging the members into clamping engagement with a ski or skis.

7. The towing device claimed in claim 1 having a volume and weight ratio sufficient to float.

8. The towing device claimed in claim 5 including means for limiting the movement of said members away from each other.

9. The towing device claimed in claim 5 including spring means for urging the two members together with a force less than that which permits the stripping of the members from the ski.

10. The towing device claimed in claim 6 including flexible rope members extending from said handle and connected to one pair of said arms outwardly of the pivot means.

11. The towing device of claim 1 wherein said means for moving said crossmembers includes:

a pair of arms connected to the ends of said crossbars and extending radially therefrom;

aligned pivot pins respectively connecting one of each pair of arms together for permitting swinging movement of said crossmembers while maintaining said members in parallel relationship;

arms connected to and projecting radially from one of said crossmembers in a direction opposite to the direction in which the first-mentioned arms project; and

control means for said last-mentioned arms.

12. The towing device of claim 11 wherein said control means includes:

a pair of flexible control ropes connected by their ends to the ends of said last-mentioned arms; and

a handle maintained in parallel relationship with said crossmembers by said ropes when said handles are urged away from said crossmembers. 13. The towing device claimed in claim 2 wherein the arms connected to one of the crossmembers are longer than the arms connected to the other of the crossmembers, whereby an obtuse triangle is formed by the arms with the apex of the arms being at the pivotal connection between said arms.

14. The towing device claimed in claim 2 wherein the arms connected to one of the crossmembers are shorter than the arms connected to the other of the crossmembers, whereby an acute triangle is formed by the arms with the apex of the arms being at the pivotal connection between said arms.

15. The towing device claimed in claim 2 wherein the arms connected to one of said crossmembers is approximately equal in length to the arms connected to the other of the crossmembers whereby an isosceles triangle is formed with an apex at the pivotal connection between the arms.

16. The towing device claimed in claim 6 wherein said firstmentioned means also includes a pair of ropes of equal length connected respectively to the ends of said handle and to said first pair of arms for disposing said handles at an appropriate distance from a ski when said towing device is attached to a ski for the handle to be grasped by the skier.

17. The towing device claimed in claim 16 wherein said towing device is ofa width to receive a plurality of skis.

Claims

1. A towing device for water ski comprising: a pair of crossmembers movable toward and away from each other for clamping a ski therebetween; a towrope attached to said crossmembers; and means for moving said crossmembers relative to each other into a clamping engagement with the ski during an initial period when said ski is to be pulled by said rope and for thereafter releasing said crossmembers sufficiently for the device to be stripped off the end of the ski by said towrope.

5. The towing device claimed in claim 1 wherein said means includes: a first pair of arms extending radially from the ends of said members; a second pair of arms extending radially from the other of said members; first pivot means for pivotally connecting one arm of said first pair of arms to one arm of said second pair of arms; second pivot means for connecting the other of said one pair of arms to the other of said second pair of arms; and said first and second pivot means being aligned for permitting swinging movement of said members with respect to each other while maintaining said members in parallel relationship.

6. The towing device claimed in claim 5 wherein said first-mentioned means includes a handle for urging the members into clamping engagement with a ski or skis.

11. The towing device of claim 1 wherein said means for moving said crossmembers includes: a pair of arms connected to the ends of said crossbars and extending radially therefrom; aligned pivot pins respectively connecting one of each pair of arms together for permitting swinging movement of said crossmembers while maintaining said members in parallel relationship; arms connected to and projecting radially from one of said crossmembers in a direction opposite to the direction in which the first-mentioned arms project; and control means for said last-mentioned arms.

12. The towing device of claim 11 wherein said control means includes: a pair of flexible control ropes connected by their ends to the ends of said last-mentioned arms; and a handle maintained in parallel relationship with said crossmembers by said ropes when said handles are urged away from said crossmembers.

13. The towing device claimed in claim 2 wherein the arms connected to one of the crossmembers are longer than the arms connected to the other of the crossmembers, whereby an obtuse triangle is formed by the arms with the apex of the arms being at the pivotal connection between said arms.

16. The towing device claimed in claim 6 wherein said first-mentioned means also includes a pair of ropes of equal length connected respectively to the ends of said handle and to said first pair of arms for disposing said handles at an appropriate distance from a ski when said towing device is attached to a ski for the handle to be grasped by the skier.

17. The towing device claimed in claim 16 wherein said towing device is of a width to receive a plurality of skis.