US3473486A

US3473486A - Method and apparatus for towing skiers and the like

Info

Publication number: US3473486A
Application number: US453936A
Authority: US
Inventors: James V Harmon
Original assignee: Individual
Current assignee: Individual
Priority date: 1965-05-07
Filing date: 1965-05-07
Publication date: 1969-10-21
Anticipated expiration: 1986-10-21
Also published as: US3405651A

Description

0d. 21, 1969 J v, HARMON 3,473,486

03 AND APPARATUS FOR IOWING SKIERS AND THE LIKE 6 5 SheetsSheet l IXVEXTOR.

38 Jim-45s K l/ mwozv J. V. HARMON Oct. 21, 1969 DIE-THO} AN) APPARATUS FOR TOWING SKIERS AND THE LIKE 3 Sheets-Sheet 2 INVENTOR; Jhvss M l/menwv (Jet. 21, 1969 J. v. HARMON 3,473,486

METHOD ANQ APPARATUS FOR TOWING SKIERS AND THE LAKE 3 Sheets-Sheet 3 mullljh] United States Patent 3,473,486 METHOD AND APPARATUS FOR TQWING SKERS AND THE LIKE James V. Harmon, 227 Emerald, New Brighton, Minn. 55112 Filed May 7, 1965, Ser. No. 453,936 Int. Cl. B61b 7/06; B61c 11/02 US. Cl. 104-173 1.7 Claims ABSTRACT OF THE DISCLOSURE This invention relates to towing devices and more particularly the invention relates to relative inexpensive, highly portable towing devices and to a method for safely transporting skiers and others engaged in winter sports over snow covered ground. The invention is especially suited for temporary installations but is also useful in permanent installations as will be apparent from the following specification.

Numerous towing devices have been previously proposed for use by skiers and others engaged in winter sports. These prior devices have not been entirely successful when an attempt has been made to employ them for portable use. The most common type previously proposed includes an endless rope wrapped over sheaves at the top and bottom of the hill and a motor for driving one of the sheaves. One important reason ski tows of this type have been unsuitable as a portable unit is the necessity for a pair of supports or towers, one at each end of the rope to hold the sheaves at a sufiicient height, usually from about five to about eight feet, to prevent the center portion of the rope from contacting the ground. Trees at the right locations can, of course, be used in place of such supports but they are frequently unavailable. Furthermore, a tower of the type required is far too bulky and expensive to be used in applications for which the present invention is very well suited, viz. a device that can be easily lifted by one person and packed in an automobile trunk or pulled by hand to a nearby hill where it is to be used. Such towers, moreover, require a certain amount of time to erect which is a further disadvantage encountered in their use.

There is still another more serious disadvantage to conventional rope tows -they present a significant safety hazard particularly for inexperienced skiers, young people and children. This results from the fact that a person using a tow of this kind sometimes become entangled with the tow rope. ()ccasionally when this happens the person will fall and be dragged along the ground a substantial distance before the tow can be stopped. Tows of this type are illustrated in US. Patents 3,166,021, 2,608,935 and 2,646,- 005. The last of these patents proposes a system for moving the tow cross-country to a selected skiing site where the tow is to be set up for use. This system consists of tying one end of a rope to a tree. placing a running 100p over a gypsy spool then manually pulling the loose end of the rope tight around the spool so that the drum runs along the rope. If one desires to go in a different direction, the tow must be turned around, the rope moved and tied to another tree.

Towing vehicles of the type which can be steered in any direction by a driver have been proposed as illustrated in US. Patent 3,059,711. These devices, however,

3,473,486 Patented Oct. 21, 1969 require elaborate traction members such as screws and have to be driven to the base of the hill by an operator when others are to be brought to the top.

A variety of cable towed vehicles have been previously proposed for use in other arts. These vehicles can be divided into two types; first, those which are provided with a cable that extends away from them in one direction only. These devices, exemplified by US. Patents 2,583,557 and 2,219,515, are characterized by the ability to travel in one direction only. The second type are those which have cables extending in two directions as illustrated in U.S. Patents 2,859,704 and 2,863,399 which describe: bogies used for pulling box cars with traction being provided by a stationary electric motor mounted beneath a railroad track and US. Patents, 681,632 and 900,060 which disclose wheel supported tractors mounted upon a cable secured to a moveable trolley at each end. During operation each trolley slides the length of a stationary cable as the tractor is steered by means of the wheels over a field lying between the two stationary cables. Because the steering mechanism does not perform well in reverse, the cable is detached and the vehicle is turned around at each end of the field.

A variety of other towing devices have been previously proposed. These are either prohibitively expensive, ineffective for towing individuals over snow-covered ground or cannot be considered portable. In view of these and other defects in the prior art it is one object of the present invention to provide for skiers and the like an improved method and towing device which is inexpensive enough to be purchased by many individuals for private use.

Another object of the invention is to provide a portable ski tow which will have good traction under all ground conditions.

Still another object is to provide a ski tow which can be easily pulled to a ski location by hand or carried in the trunk of an automobile.

Another object of the invention is the provision of an improved ski tow which is capable of being manufactured at a reduced cost through the elimination of a number of parts and through the requirement for only half as much rope or cable as is normally used.

Another object is the provision of an improved ski tow which can be quickly set up for operation merely by securing two retaining elements to the ground at spaced locations.

It is a further object of the invention to provide an improved ski tow which is safer to use than previous devices of the type described through the provision of a system that enables the person being towed to control the motion of the tow and his own motion throughout operation.

It is another object to provide an improved ski tow of the type described wherein the motion of the tow and the person being towed is quickly halted should the tow strike a foreign object or other obstruction.

Yet another object of the invention is the provision of an improved ski tow with a movable motive power means, a flexible guide for steering the power means wherein the guide serves to provide driving traction for the motive power means in addition to steering it.

A more specific object of the invention is the provision of an improved tow apparatus for winter sports including a stationary cable with a motive power device mounted for movement along the cable for towing a person to the top of a hill and a further provision for allowing the motive power means to travel back to the bottom of the hill without the attention of an operator and remain at the bottom of the hill until it is to be used again.

The invention is illustrated by way of example in the drawings wherein:

FIGURE 1 is a perspective view of the invention with the upper portion of the housing removed.

FIGURE 2 is a partial plan view of the tow apparatus, the FIGURE 1, on a larger scale.

FIGURE 3 is a plan view of another embodiment of the invention as on a smaller scale than in FIGURES 1 and 2.

FIGURE 4 is a vertical sectional view on line 4-4 of FIGURE 2 but on a somewhat larger scale than FIG- URE 2.

FIGURE 5 is a perspective view of another form of the invention.

FIGURE 6 is a side elevational view of another embodiment of the invention.

FIGURE 7 is a semidiagrammatic partial plan view of yet another embodiment of the invention.

FIGURE 8 is a semidiagrammatic partial view of another form of the invention.

FIGURE 9 is a semidiagrammatic partial plan view of still another form of the invention.

FIGURE 10 is a side elevational view of another form of the invention; and

FIGURE 11 is a partial plan view of the drive assembly of FIGURE 10 on a slightly reduced scale.

Briefly stated, the method employed in accordance with a preferred form of the invention includes the following steps. It will be assumed that the apparatus is assembled generally as shown in FIGURES 1, 2, and 4 for purposes of illustration. First, the vehicle and skier are driven to a higher ground elevation in a forward direction along the cable with the cable steering the vehicle. The skier is then unloaded. Next, the vehicle is caused to reverse directions and to travel rearwardly to the starting point unattended. It is stopped when the starting point is reached and allowed to remain there until used again. In a preferred form of the invention, when traveling forwardly the cable and motor are placed in driving engagement with the driving force on the cable oriented to propel the vehicle toward the higher elevation and when the reverse direction is taken, the motor is placed in driving engagement with the line for reverse motion of the vehicle to propel the vehicle back to the starting point. The cable preferably steers the vehicle in both directions. These steps can be performed by any suitable automatic actuating means :or by hand, but they are preferably performed as described hereinbelow in connection with the figures.

The tow apparatus shown in FIGURES 1, 2 and 4 includes a base 10 consisting of a skid which serves as a ground support and is formed from sheet metal curved upwardly at the front and rear ends 10a and 10b enabling the apparatus to move easily over the surface of the ground in forward and rearward directions toward the right and left respectively as seen in FIGURE 1. Side walls 100 or the equivalent, are provided for preventing snow from spilling over the moving parts described below. As shown in FIGURE 4, a cover 11 is mounted on the base 10 to enclose the moving parts of the drive mechanism as will be described below. An opening 11a is provided for the motor which is also described below. The cover has been removed from the device in FIG- URES 1 and 2 so that the parts can be clearly seen.

A motive power means such as an internal combustion engine is mounted upon the base 10. The motor 12 has an output shaft 14 secured to a transmission means including a speed reducing and reversing unit 16 which in this case consists of a reversing planetary shaft mounted transmission manufactured by the Fairbanks Morse Company of Beloit, Wis. The transmission 16 includes a brakeband 160: which when tightened 'will cause an endless belt 18 entrained over the transmission 16 to turn in one direction and when loosened to turn in the opposite direction but at twice the rotational speed. The transmission 16 also has in it a centrifugal clutch (not shown) which becomes engaged at higher engine speeds and disengages at lower engine speeds. The brakeband 16a is secured by a pivot 20 to a bar 22 which is itself connected to a stationary block 24 by means of a pivot 26. The end of the bar 22 is secured to a rod 28 which is fastened at the other end to a tube 30. The tube 30 is in turn welded to an operator support means, rest or restraining means which consists of the handle 32 that projects rearwardly and upwardly on an incline and is provided at its rearward end with handle grips 34. A rope 33 is secured to the free end of the handle. Pivotally connected at each end between the ends of the tube 30 and the base 10 are a pair of

parallel links

36 and 38 to support the handle 32 and rod 28 for movement between forward and rearward positions. A stop 39 welded to the tube 30 limits the downward movement of the handle 32 by contact with link 36. A tension spring 40 is secured between the tube 30 and the base 10 for yieldably biasing the handle 30 toward a forward position. A dashpot 42 similarly connected limits the speed with which the handle can move. This speed can be controlled by changing the setting of an adjustment knob 44.

The rearward end of the belt 18 is entrained over a sheave 46 which is secured to a shaft 48 mounted for rotation upon bearings 50 and 52. Also secured to shaft 48 is a sprocket 54 engaged by means of a chain 56 to a sprocket 58. The sprocket 58 is connected rigidly to a shaft 59 which is in turn supported by bearings 60 and 62. Attached to the center of the shaft 59 is a drive means consisting of a hub or drum 64 having three circumferential grooves thereon. A similar drum 66 is secured to a shaft 68 mounted for free rotation on

stationary brackets

70 and 72. The transmission 16, belt 18, sheave 46, the sprockets and chain 36 can be considered a means for operatively connecting the motor and the drive means.

Entrained over the

drums

64 and 66 is an elongated flexible steering line 74 which consists in this instance of /8" diameter galvanized steel aircraft cable. The forwardly extending section of the cable passes through a holder consisting of a steel tube 76 secured to the base 10. A similar holder 78 is secured to the rear of the base 10. The term steering as used herein means capable of holding to a predetermined course. The term steering means refers to a device which will restrict the direction of movement of a vehicle over the ground to a predetermined course.

As is clearly shown in FIGURE 4 a fixed retaining means such as a clamp or knot 77 is secured to the end of cable 74 for fastening the cable to a stationary element such as a stake 78 which serves to hold the upper end of the cable 74 in a predetermined and fixed position. A similar retaining means 80 is used for securing the lower end of the cable 74 to a stake 82 to hold it also in a fixed and predetermined position. A guard such as pipe 83 is mounted over the cable 74 adjacent stake 82 to prevent the stake 82 from contacting the bumper described below.

The motor 12 is provided with a speed control means comprising a throttle lever 88 connected directly to the butterfly valve of the carburetor 90. The lever 88 extends laterally beyond the side of the base 10. In the solid line position of FIGURE 2, the throttle lever 88 will operate the motor 12 at low speed and in the dotted line position the motor will run at a higher speed. The lever 88 is mounted such that it will remain in either extreme position when so placed. At the bottom of the hill is mounted a stationary element such as a stake 89 in the path of lever 88. A manually operated hand throttle lever 92 is mounted upon the handle 34 in position to be used by the operator. The lever 92 is yieldably biased to a throttle closing position in any well-known manner and is connected to the throttle 88 by a cable 94.

A pair of bumpers 96 "and 98 formed from wire are mounted on the front and rear of the base 10 and are yieldably biased toward outward positions by springs 96a and 9811 respectively. The bumpers each include laterally extending segments 96b and 98b which serve to hold in place and in closed condition switches wired in series with the motor ignition. If any of the segments 96b and 98b are moved centrally, corresponding switches will fall, then open the circuit and the motor will stop. It will be apparent that both of

drums

64 and 66 can be driven if desired. When traction is provided by the cable 74 as here, the cable can 'be considered a part of the drive means.

The operation of the device of FIGURES 1, 2 and 4 will now be described. After the device is removed from storage, it is either pulled to a location where it is to be used by means of the handle 32 or the handle removed and the entire apparatus placed in a vehicle such as an automobile trunk for transportation to the desired location. The

stakes

78 and 82 are then driven into the ground with a hammer. The cable 74 is tightened and the ends are secured to the stakes. The motor 12 is then started. The operator should then grasp the handle 32, pull back and simultaneously depress the hand throttle lever 92. As the motor 12 picks up speed, the centrifugal clutch will become engaged and the entire unit 16 will begin to turn in a clockwise direction as seen in FIGURE 4 thereby imparting motion to the belt 18, chain 56 and drum 64 in the proper direction to pull the motive power means, base and operator along the cable 74 toward the top of the hill. When the top of the hill is reached, the operator should release the handle 32 and throttle lever 92. The engine will then slow down to idling speed. This will disengage the clutch causing forward motion of the device to be terminated. The spring 40 will draw the handle 32 forwardly at the speed determined by dashpot 42. This will cause the rod 28 and bar 22 to move forwardly releasing the brake 16:: thereby reversing the unit 16. The base 10 will remain in place until the operator moves lever 88 with his hand or ski pole to the rearward dotted line position as seen in FIGURE 2. The higher engine speed will then engage the clutch causing the unit to be steered by the cable 74 back to the bottom of the hill. When the unit reaches the lower end of the hill, the throttle lever 88 will strike the stationary element 89 and move it to the solid line position in FIGURE 4. This will cause the engine to idle thereby disengaging the clutch. The unit will remain in this condition until it is to be used again. One, two or more people can be towed at the same time by holding either the handle 34 or the rope 33. The disengagement of the clutch at the lower end of the cable, can be thought of as a means for stopping the device without damage to the engine drive means or cable.

It should be noted that if the hand throttle 92 is released at any time, the engine 12 will idle and the tow will stop thereby insuring safe operation of the unit under all conditions. The apparatus will also stop if an obstruction strikes either of

bumpers

96 or 98. With the transmission 16 in forward drive it will operate at relatively low speed thereby providing higher torque for pulling the operator up hill when power is most needed. When operated in reverse, it will provide greater speed of movement over the ground thereby enabling the base 10 to reach the bottom of the hill in the shortest possible time. The high reverse speed thus provides a more etiicient device than one having the same speed in both forward and reverse operation. When a dip in the ground is traversed by the unit, it will be supported in whole or in part by the cable 74 rather than the base 10.

The apparatus of FIGURE 3 is generally similar to the unit illustrated in FIGURES l, 2 and 4 and the same parts are given corresponding numbers except as will now be described. A spring 91 is moun.ed loosely over the rope 74 and at the free end of the spring 91 is mounted a ball 93 adapted to slide freely on the rope 74. Moveably mounted upon the base 10 by means of a pivot 95 is a speed control member such as a lever 97, one of the ends is connected to a spring 99 mounted slidably over the cable 74. The operation of the unit of FIGURE 3 is similar to that of FIGURES 1, 2 and 4 except that it is unnecesary to mount the stationary element such as post 89 in the ground in the path of a throttle lever. Instead, when the base 10 and the engine 12 travels toward the lower end rope 74, the distal end of the spring 99 will engage the ball 93 thereby moving the speed control 97 which in turn will reduce the speed of the motor. While the speed control member 97 is preferably connected to the throttle of the engine 12 it can also be connected for disengaging a clutch or engaging a brake.

Refer now to FIGURE 5 which shows another form of the invention consisting of a movable unit or car 101 with a flat base 102 having upwardly turned front and rear ends, a motor 104 and a sheet metal enclosure 106 upon which is mounted an operator rest or restraining means consisting of a seat 108 with a back 110. A speed control consisting of a handle 112 is operatively connected to the motor for regulating the speed of the unit 101 along the length of a steering cable 114, one end of which is secured at the top of the hill and the other end of which is secured at the bottom of the hill.

Within the enclosure 106 is a suitable drive means (not shown) of known construction such as that of FIG URES 1 and 2, which connects the motor 104 to the cable 114. The car also includes a direction reversing means of any conventional construction connected to handle 112 for reversing the direction of car 101 when the handle 112 is moved to its extreme forward position.

The upper end of the cable 114 is secured to a retaining means which consists in this case of a winch 116 having a suitable locking provision such as a sprag 118 for preventing reverse rotation of the winch after it has been tightened. The winch 116 provides a means for conveniently storing the cable as well as a means for effectively tightening the cable 114. While the force exerted upon the cable can be varied greatly depending upon the size of the unit and operating conditions, it has been found that satisfactory operation can be obtained under many circumstances with a force of from about twenty to abo t two hundred pounds exerted upon the cable. If an auxiliary cable tightener is provided upon the vehicle for maintaining the cable wrapped tightly over the drive means, no tension need be present between the end of the cable. The winch 116 is secured in place by means of a stake 120.

Refer now to FIGURE 6 which illustrates another form of the invention including a movable car or unit 120 having a restraining means consisting of a seat 122 on the upper surface thereof with a back rest 124. The unit 120 also includes a base or framework 126 upon which the seat is mounted. Also mounted upon the framework 126 is a motor 128 operatively connected as by belt 130 to a drive means which in this instance consists of an endless track 132 entrained over a pair of spaced apart rolls 124 and 135 supported for rotation on parallel horizontally disposed axles at the front and rear of the framework 126. The endless track includes a plurality of longitudinally spaced and transversely extending flights 138 which engage the ground. The unit 120 also includes a handle 140 operatively connected to the drive means 128 for reversing the direction of the belt 130 when desired.

Extending through holders mounted on the unit 120 but not directly connected thereto is an elongated flexible guide means such as a cable 142, the ends of which are fastened to the ground with stationary elements such as

stakes

144 and 150. The unit 120 is free to move on the cable 142 in either direction since there is no mechanical coupling between the cable 142 and the framework 126 or the drive means 128. At the rear of the unit there is provided a rearwardly extending lever 148 that is connected to the drive means for stopping the drive means when moved forwardly. A stationary element, in this case the stake 150, is positioned to strike the rearward end of the lever 148 and move it forwardly when the 7 unit 120 approaches the stake from the right as seen in FIGURE 6.

The operation of the apparatus illustrated in FIGURE 6 will now be described. The unit 120 is first placed in position for operation as shown in FIGURE 6 and the motor 128 is started. The control lever 140 is then moved to the solid line position of the figure causing the drive means to move the belt 130 and roll 136 in a clockwise direction as seen in the figure. The movement of the roll 136 is imparted to the track 132 which will in turn move the entire unit 120 toward the right of the figure, its motion being guided by the cable 142. When the stake 144 is reached, the lever 140 is pulled rearwardly a sufiicient distance to stop the drive means. The operator should then get off. When the lever 140 is in the dotted line position of the figure, the unit will be driven in the reverse direction (toward the left of FIGURE 6). The unit will travel along the cable 142 toward the left until the lever 148 strikes the stationary stake 150 so as to stop drive means. The unit will remain in this position until it is ready to be used again at which time the cycle is repeated. This embodiment of the invention has the advantage that no load is placed on the cable 142. The drive means must however be somewhat greater in size and complexity than that of the other forms of the invention.

Refer now to FIGURE 7 which illustrates another form of the invention generally similar to that illustrated in FIGURES 1, 2, 3 and 4 with the same numbers given to corresponding parts. The unit of FIGURE 7 includes a somewhat different form of control system which will now be described. Connected to the engine shaft is a clutch C and to the output shaft of the clutch C is secured a reversing transmission T. The transmission T includes an output shaft which is connected directly to the drum 66. Drum 64 in this case idles. The transmission T includes forwardly extending control rod 160 having a laterally extending segment 162. Secured to the ground near the top of the hill in front of the vehicle and in position to strike the segment 162 is a stationary element such as a stake 164. A lever 166 is mounted upon the base by means of a pivot 168 and is connected to the rod 160 by means of a pin 170. The throttle 172 is connected by means of a link 174 with a control rod 176 which is pivoted at 178 for movement between a solid line position adapted to run the engine at a low speed and a dotted line position adapted to run the engine at a higher speed. The handle 32 in the embodiment of FIG- URE 7 is not mounted on the base 10 for movement between forward and rearward positions but instead is pivoted thereto by means of

pins

180 and 182. A cable 184 extends between the clutch and the top of the handle so that the clutch C can be controlled by an operator grasping the handle.

The operation of the unit illustrated in FIGURE 7 will now be described. With the motor 12 in operation and the clutch engaged, the lever 166 and the rod 160 moved forwardly, the entire unit will travel along the cable 74 toward stake 164 at the top of the hill. When the top of the hill is reached, the operator disengages the clutch C by pulling on the cable 184 and allows the throttle lever to remain in the high speed or dotted line position of FIGURE 7. The clutch is then reengaged. Under these conditions, the unit will continue to travel upwardly toward the stake 164. Alternatively, the operator can merely release the handle 32 and allow the unit to continue to travel toward the stake 164. When the segment 162 of the rod 160 strikes the stake 164, the transmission T will be reversed thereby reversing the direction of movement of the entire unit along the cable 74. The unit will then travel toward the lower end of the cable. Before the lower end of the cable 74 is reached, the rod 176 will strike a stationary object such as a stake (not shown) adapted to move it from the dotted line position to the solid line slow speed position causing the engine to idle.

When the unit is ready to be used a second time, the handle 166 is moved forwardly by hand thereby shifting the transmission T to forward drive.

Refer now to FIGURE 8 which illustrates still another embodiment of the invention wherein corresponding parts have the same numerals as in FIGURES 1, 2, 3 and 4. To the motor 12 is connected a clutch C and a reversing transmission T, the latter being connected by means of a bar to the tube 30 such that forward movement of the handle 32, tube 30 and rod 190 will place the transmission in reverse drive (movement will then be along an axis extending toward the base of the figure). Forward drive will be provided when the handle 32 is pulled toward the bottom of the figure. In the apparatus of FIGURE 8 as in FIGURE 7, traction is provided by the drum 66 rather than drum 64. A lever 192 extends laterally from the clutch C in position to strike a stationary object such as a stake 194 which is driven into the ground near the lower end of the hill adjacent to cable 74. A throttle cable 196 is connected between the engine and the free end of the handle 32 for allowing the operator to change speeds as required.

In operation, a person using the tow of FIGURE 8 should first push the entire unit away from the stake 194 to engaging the clutch. Next, the operator should pull back on the handle 32 to shift the transmission into forward drive. As this is done, the operator should also move the throttle cable 196 in the direction adapted to open the throttle. The entire unit will then travel along the cable 74 to the top of the hill with the operator holding the handle 32. The operator should then release the handle and allow it to move forwardly under the control of the spring 40 and dashpot 42. The transmission T will then reverse directions and begin to travel toward the lower end of the cable 74. When the unit reaches the bottom of the hill, the clutch will be disengaged as lever 192 strikes the stake 194. The unit will remain in this position with the engine idling until it is to be used again.

This embodiment of the invention has the advantage of being capable of reversing direction without attention and traveling back to the bottom of the hill from any point on the hill unlike the embodiment illustrated in FIGURE 7. Any of a wide variety of clutches can be used and any one of numerous revresing transmissions can be employed. Moreover, only one stake or other stationary element is required in addition to those at the ends of the cable whereas two are needed in the apparatus in FIGURE 7.

Refer now to FIGURE 9 which illustrates still another form of the invention. As can be clearly seen in the figure, a cable 203 is connected to the carburetor of the engine 12 to allow regulation of the throttle from the rearward end of the handle 32. Connected to the shaft of the motor 12 is a speed reducing transmission 204 adapted to drive the unit in one direction only viz. toward the top of the hill (forward drive). Connected between the transmission 204 and the drive drum 66 is a centrifugal clutch 206 constructed to disengage at low speeds and to become engaged at higher engine speeds. In this embodiment of the invention as in FIGURES 7 and 8 the unit is driven by drum 66 rather than the drum 64.

During operation, the user first opens the throttle by pulling on cable 203 thereby engaging the clutch 206 which in turn causes the unit to move towards the top of the hill (the top of FIGURE 9). When the top of the hill is reached, the operator releases the cable 203 to slow the motor and thereby disengage the clutch 206. With the clutch disengaged, the unit is free to travel back toward the bottom of the hill under the influence of gravity. The unit will stop when its momentum is lost or when it strikes the stake or other fastener which the bottom of the cable 74 is afiixed. This embodiment of the invention has several advantages among them being simplicity of construction, low cost and the lack of a requirement for a reversing mechanism or control for reversing the drive. In addition, no stakes or other stationary elements are required at the top or bottom of the hill aside from those at the ends of the cable. This embodiment of the invention will perform satisfactorily where there is a relatively steep slope or where the slope is either icy or particularly smooth.

Refer now to FIGURES l and 11 which illustrate another form of the invention comprising a flexible guide such as a cable 220, the ends of which are secured at the top and bottom of the hill in any convenient manner and a towing unit indicated generally at 222 which is mounted for movement along the cable with the cable steering the unit 222 in both directions. The towing unit 222 includes a base consisting of a pair of parallel horizontally

disposed skis

224 and 226 having upturned sections at each end. A pair of laterally aligned and abutting

pulleys

225 and 227 are mounted upon each end of the base, only one of each pair being shown. The cable 220 passes between each pair during operation.

Secured between the

skis

224 and 226 is a sheet metal riser 228 having the form of an inverted U when seen from the front. Mounted upon the riser 228 is an engine 230 including a speed reducer 232 with an output shaft 234 to which a sheave 236 and a gear 238 are affixed. When the unit travels in a forward direction (toward the left in FIGURE power is conveyed from sheave 236 through a belt 239 to a sheave 240 affixed to a drive means consisting of a circumferentially grooved spool 242. A section of the cable 220 is wrapped around the spool 242, and extends in either direction beneath a pair of

pulleys

239 and 241 supported for rotation between two identical vertically disposed and parallel plates 144 and 146 suitably fastened at their lower ends to riser 228. A lever 250 having two parallel legs 250a and 25% is supported between the plates upon a pivot 252. The sheave 240, spool 242 and a gear 254 are all afiixed to a shaft 256 mounted for rotation at each end upon legs 250a and 25017.

A pin 258 which is rigidly connected to the lever 250 engages a rod 260 welded to an angle iron 262 which is itself yieldably biased by a spring 264 to force the sheave 240, gear 254 and spool 242 forwardly to a neutral position indicated by a dotted line 266 representing the new position taken by the gear 254. In this position no power will be transmitted from the engine 230 to the cable and the unit 222 will remain stationary.

When the motion of the unit is to be reversed, a handle 267 (only a part being shown) secured to the free end of lever 250 is moved forwardly by the operator until the gear 254 reaches dotted line position 269 and becomes engaged with gear 238. The friction of pivot 252 will maintain the gears in engagement until the unit 222 reaches the bottom of the hill and extension 268 of the lever 250 strikes a stationary element such as a stake 270 driven into the ground near the lower end of the cable in the path of the extension 268. The sheave 240 and gear 254 will then move to the neutral dotted line position 266 and the unit 222 will stop.

When the tow of FIGURES 10 and 11 is to be used again, the operator should grasp the handle 267, pull it rearwardly against the tension of spring 264 until the belt 239 is tight. The throttle is simultaneously advanced by operating a throttle cable 272.

It will be apparent to those skilled in the art that many modifications and variations of this invention as hereinbefore set forth may be made once the principles of the invention are understood without departing from the spirit and scope thereof.

I claim:

1. A portable tow for transporting persons engaged in winter sports over snow covered ground comprising an elongated flexible steering line adapted to be secured at each end to the ground in a stationary position, a motive power means for movement along the line toward either end thereof, a drive means connected between the motive power means and the flexible steering line for moving the power means in a first direction along the line, and operator restraining means connected to the motive power means to carry a person with the motive power means as the motive power means travels toward one end of the line and means operatively associated with the motive power means and the drive means including a selectively operable means for causing the motive power means to be free to move opposite said first direction until the other end of the line is reached without said operator on the estraining means.

2. A portable towing apparatus for transporting persons on snow covered ground comprising a vehicle including a base, a ground support on the base for allowing the vehicle to travel easily on the surface of the ground, a motor mounted on the base, a reversing transmission operatively connected to the motor, said transmission having an output shaft, a moveable control element connected to the transmission for changing the direction of rotation of the shaft, a drive means connected to the shaft, an operator restraining means on the vehicle for supporting said persons in a predetermined position relative to the vehicle, a flexible line having an upper and lower end, said line being connected to the drive means to provide traction for the vehicle, a speed control element moveably mounted on the vehicle for starting and stopping the drive means, and a stationary element adapted to be placed adjacent the lower end of the line in position for engagement with the moveable speed control element to stop the drive means when the vehicle approaches the lower end of the line and the speed control element contacts the stationary element.

3. A towing apparatus for skiers and the like comprising a stretched steering and traction cable, a retainer member connected to each end of the line for securing the ends of the line in stationary positions on the ground, one end being positioned at a higher ground elevation than the other end, a vehicle mounted upon the cable, a motor on the vehicle, a reversing transmission connected to the motor, said transmission having an output member, a moveable control element on the transmission for changing the direction of rotation of the output member, and a drive means connected to the output member for moving the vehicle longitudinally of the line whereby the vehicle will be steered by the line along a predetermined course when moving toward either end of the line and a means for causing the vehicle to stop without damage to the cable or drive means when the vehicle reaches said other end of the cable.

4. A reversible tow device for transporting skiers up a hill comprising a vehicle, a stationary cable operatively connected to the vehicle for steering the vehicle, a motor mounted on the vehicle for driving the vehicle along a path which is coextensive with the cable, a reversing transmission connected to the motor and having an output shaft in driving engagement with the cable for controlling the direction of movement of the vehicle along said path, said transmission having a forward position for driving a vehicle up the hill and a reverse position for driving the vehicle down the hill, a moveable control means connected to the transmission for shifting the transmission between said forward and reverse positions, a biasing means connected to the control means for urging the control means toward said reverse position whereby the vehicle will be driven toward the bottom of the hill when the control means is released.

5. The apparatus according to claim 4 wherein the control means comprises a handle extending from the vehicle and moveably mounted thereon to be grasped by a skier for supporting the skier in a predetermined position relative to the vehicle.

6. The apparatus according to claim 4 wherein said transmission includes a speed changing means connected to operate the output shaft at a higher rotational speed when in the reverse than when in the forward drive.

7. A ski tow device comprising a cable, a vehicle mounted for movement along the cable, a motor on the vehicle, a drive means connected to the motor, a retaining means at each end of the cable for securing the respective ends of the cable to the ground to hold the cable in a stationary position adjacent to the ground, a safety bumper on the vehicle operatively connected to the drive means for halting the motion of the vehicle when the bumper is struck by an object at any position of the vehicle on the cable.

8. The apparatus of claim 7 wherein the drive means is constructed to propel the vehicle in either direction along the cable and two said bumpers are provided on the vehicle, one said bumper on a side of the vehicle facing toward one end of the cable and the other bumper on the side of the vehicle facing the other end of the cable.

9. A ski tow comprising a vehicle, a flexible elongated steering means, a means for connecting each end of the steering means to the ground, a motive power means, a drive means connected to the motive power means for propelling the vehicle along the path defined by the steering means, a handle on the vehicle adapted to be grasped by a skier when the skier is to be pulled up the hill and the throttle control lever on the handle in position to be moved by the operator to permit the operator to control his speed, said handle being connected to the vehicle for movement between first and second positions and the handle is connected to the drive means to reverse the direction of the driver means when the handle is moved from said first to said second position.

10. A ski tow comprising a vehicle, a flexible elongated steering means, a means for connecting each end of the steering means to the ground, a motive power means, a drive means connected to the motive power means for propelling the vehicle along the path defined by the steering means, a handle on the vehicle adapted to be grasped by a skier when the skier is to be pulled up the hill and the throttle control lever on the handle in position to be moved by the operator to permit the operator to control his speed, a fixed member adapted to contract the drive means when the vehicle approaches the upper end of the flexible steering means and thereupon reverse the direction of movement of the vehicle.

11. A ski tow device for winter sports comprising a vehicle, a motive power unit on the vehicle, a cable connected to the vehicle, a means at the ends of the cable for rigidly aflixing the ends of the cable to the ground, a drive means connected to the motor, a handle on the vehicle to hold a person in a selected position on the vehicle, a manually operable control means on the vehicle for regulating the speed of the vehicle, a clutch connected between the drive means and the motor, a control lever for the clutch and a stationary member adapted to engage the lever when the vehicle reaches the lower end of the hill.

12. A ski tow comprising a vehicle, a motor mounted on the vehicle, a drive means connected to the motor, a stationary cable engaged upon the drive means to provide traction for the vehicle, means at each end for securing the ends of the cable to the ground and a tightener means at one end of the cable for placing the cable under tension, said tightener comprising a winch with a means for maintaining the winch in a selected rotational position.

13. The apparatus of claim 11 including a belt drive between the power unit and the drive means and wherein the clutch comprises a tightener for the belt.

14. The apparatus of claim 13 wherein the handle is connected to move to a first position wherein the belt is tightened and to a second position for releasing the belt and for connecting the motive power means to run the drive means in a direction opposite that imparted by the belt.

15. The apparatus of claim 14 wherein said reversing means comprises a first gear mounted coaxially of the drive means and a second gear connected to the engine and mounted in a fixed position upon the vehicle, said drive means and first gear being mounted upon the vehicle for movement along an axis extending toward and away from the second gear and said handle being connected to move the drive means along said axis.

16. A method for transporting skiers and the like over snow covered ground from a starting point to a higher elevation with a flexible line and a vehicle having a motor, said method comprising placing the motor and line in driving engagement with the driving force on the line oriented to propel the vehicle to said higher elevation, steering the vehicle with the line while the vehicle is thus propelled, interrupting the driving force between the motor and the line, unloading the skier from the vehicle, next placing the motor into driving engagement with the line for reverse motion of the vehicle to propel the vehicle back to the starting point, steering the vehicle with the line while traveling toward the starting point, stopping the vehicle when the starting point is reached and allowing the vehicle to remain at the starting point until it is to be used again.

17. A towing apparatus comprising a stationary cable positioned with one end at a higher ground elevation than the other, a vehicle mounted for movement along the cable, a motor on the vehicle, a drive means, a centrifugal clutch connected between the motor and the drive means for propelling the vehicle toward said higher elevation when the clutch is engaged, a throttle connected to the motor, whereby the slowing of the motor will disengage the clutch and thereby free the motor from the drive means to allow movement of the vehicle toward the lower end of the cable.

References Cited UNITED STATES PATENTS 2,542,374 2/ 1951 Torrani 104-169 2,608,935 9/1952 Moore 104173 2,646,005 7/ 1953 Swenson 104-173 916,081 3/1909 Williams 104l 17 1,201,206 10/ 1916 Lewis 104--88 FOREIGN PATENTS 1,155,822 5/1958 France.

ARTHUR L. LA POINT, Primary Examiner D. F. WORTH, III, Assistant Examiner U.S. Cl. X.R. 104-178 Disclaimer 3,473,486.James V. Harmon, New Brighton, Minn. METHOD AND AP- PARATUS FOR TOWING SKIERS AND THE LIKE. Patent dated Oct. 21, 1969. Disclaimer filed May 15, 1969, by the inventor. Hereby disclaims the terminal portion of the term of the patent subsequent to Oct. 15,1985.

[Ofiicial Gazette January 13, 7970.]