US3826323A

US3826323A - Propelling apparatus for skiers

Info

Publication number: US3826323A
Application number: US00350371A
Authority: US
Inventors: A Mehne
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-04-12
Filing date: 1973-04-12
Publication date: 1974-07-30
Anticipated expiration: 1991-07-30

Abstract

Motor powered apparatus for propelling a skier on skis and which is portable on the skier''s back in which a motor powered unit having an endless track has pivotally connected thereto a frame which extends upwardly and forwardly of the unit. The skier is partially supported by the end of the frame and by his skis, and separation of the skis and the unit is limited by straps attached to the unit and the skier''s ankles. The frame can be detached from the unit and can be used in its inverted position to carry the unit on the skier''s back.

Description

United States Patent [1 1 Mehne PROPELLING APPARATUS FOR SKIERS [76] Inventor: Albert R. Mehne, 9 Susquehanna Rd., Ossining, NY. 10562 [22] Filed: Apr. 12, 1973 [21] Appl. No.: 350,371

[52] U.S. Cl 180/5 R [51] Int. Cl B62m 27/02 [58] Field of Search ISO/9.22, 5 R

[56] References Cited UNITED STATES PATENTS 3,509,955 5/1970 Lichfield 180/5 3,568,787 3/1971 Gremcretm. 180/5 R 3,610,355 lO/197l Buck 180/5R 3,645,348 2/1972 Thompson 180/5 R- FOREIGN PATENTS OR APPLICATIONS 479,495 3/1953 Italy 180/5 R l7 1 1e b f 11] 3,826,323 [451 July 30,1974

1,042,943 9/1966 Great Britain 180/5 R 1,169,880 9/1958 France 180/5 R Primary Examiner-Richard J. Johnson Attorney, Agent, or Firm-Brooks Haidt & Haffner [57 ABSTRACT wardly and forwardly of the unit. The skier is partially supported by the end of the frame and by his skis, and

separation of the skis and the unit is limited by straps attached to the unit and the skiers ankles. The frame can be detached from the unit and can be used in its inverted position to carry the unit on the skiers back.

11 Claims, 6 Drawing Figures- PAIENTEU JULSOIQH SHEET 1 BF .3

PATENTED JUL 3 0 I974 SHEET 2 BF 3 PATENTEU Jul 3 0 I974 SHEEI 3 0F 3 PROPELLING APPARATUS FOR SKIERS This invention relates to motor powered, skier propelling apparatus and particularly to apparatus including a self-contained, motor driven tractor which is portable on the back of a skier and which may be used to propel a skier up hills.

It is accepted in the art that motor powered propelling apparatus for skiers is desirable, particularly in the absence of a ski lift or for cross-country use. See, for example, U.S. Pat. Nos. 3,509,955; 3,610,355; 3,568,787 and 3,645,348.

One of the problems in the design of such apparatus is to provide sufficient propelling power while keeping the apparatus as compact and light in weight as possible. It is required that the apparatus be transportable on the back of the skier during downhill runs, and therefore, it is essential to keep the apparatus both compact and light in weight and to make it easy to secure it to the back of the skier. v A On the other hand, if the apparatus is too light in weight, it does not dig into the snow sufficiently to provide the necessary traction. Attempts have been made to overcome this problem by having the skier sit on the tractor, but usually, the weight of the skier is far more than is necessary for the required traction. In addition, when it is possible to sit on the tractor, the skier usually maintains all his weight on the tractor even if part of his weight could be placed on his skis, particularly since it is difficult, from a sitting position, to place some of the skiers weight on the skis for any length of time.

I have found that if the weight of the skier is borne almost entirely by the apparatus, then a relatively large and heavy gasoline fuelled engine is required to drive the apparatus even at relatively low speeds, because the tractor sinks too far into the snow. However, if the weight of the skier is distributed properly between the apparatus and his skis, e.g., 40-60 percent on the skis and 60-40 percent on the apparatus, preferably about onehalf on each, then, a relatively light weight gasoline fuelled engine can be used to drive the apparatus satisfactorily at higher speeds. Since the engine makes up a substantialproportion of the weight of the apparatus, it will be apparent that if the apparatus is such that it will be convenient, and used naturally, with the proper weight distribution, the apparatus can be made relatively small in size and weight without sacrificing performance.

One object of the invention is to provide apparatus for propelling a skier on skis which is lighter in weight and smaller insize than similar apparatus previously known.

Another object of the invention is to provide apparatus of the aforesaid type which has sufficient traction in spite of the relatively light weight thereof to propel a skier on skis at higher speeds without traction problems.

In accordance with the preferred embodimentof the invention, a self-contained, propelling or motive unit comprising an endless track driven by a motor or'engine supported by the track has a longitudinally rigid frame pivotally connected thereto, so that, in use, the frame extends upwardly from the unit and in the direction of propulsion. The frame, at a portion remote from the unit, has means for receiving a portion of the skiers body, e.g., the lower portion of his buttocks, when the skier is standing on his skisin front of the unit but leaning backward toward the unit and when the longitudinal plane of the frame isat an angle of substantially less than 90, e.g., 40-75, to the direction of movement of the unit. Preferably, the frame is designed to be usable as a pack frame for the unit when it is carried on the skiers back, and a belt, which may be used in securing the frame on the skiers back, extends from said portion of the frame to secure said portion to the skier, e.g., at his hips, during use of the unit for propelling purposes. To limit separation of the skis and the unit when the skier is so leaning backward against the frame, limiting means, such as a pair of straps, each secured at one end to the unit and secured at the opposite end to the skier, e.g., his ankles, or the skis, is provided.

Other objects and advantages of the inventiontwill be apparent to those skilled in 'theart from the following detailed description of the presently preferred embodiment thereof, which description should be considered in conjunction with the accompanying drawings 'in which:

FIG. 1 is a perspective view illustrating a preferred embodiment of the apparatus of the invention asit is used to propel askier on skis; 7

FIG. 2 is a side elevation view of the embodiment in FIG. 1;

FIG. 3 is a side elevation view illustrating the apparatus of FIGS. .1 and 2 as it is carried by a skier;

FIG. 4 is an enlarged, perspective view of the frame forming part of the apparatus shown in the preceding figures; and

FIGS. 5 and 6 are, respectively, enlarged side elevation and plan views of the motive or tractor unit form ing part of the apparatus of the invention.

In the embodiment of the invention illustrated in FIGS. 1 and 2, a skier l is standing on skis 2 and 3 supported on snow and is leaning backward with respect to the vertical so that the buttocks of the skier are resting on a wide band 4 of reinforced flexible material extending between and secured to a pair of longitudinally, rigid,

tubular members

5 and 6 forming part of a frame 7. The

tubular members

5 and 6 are held in spaced, parallel relation by a pair of tubular cross members-8 and 9 which are secured at their ends to the

tubular members

5 and 6. The

upper ends

10 and 11 of the

members

5 and 6 are secured to the ends of a-flexible bet 12, which extends around the waist of the skier 1 for securing the upper end of the frame 7 to the skier.

The lower ends of the

members

5 and 6 are received in sockets l3 and 14 which are pivotally secured to the midportions of a pair of

side members

15 and 16 forming part of the chassis of the motive unit designated generally by the reference numeral 17. It will be noted that the frame 7 extends upwardly of the motive unit 17 and forwardly thereof, the direction of propulsion being indicated by the arrow 18. By reason of the pivotal connection of the frame 7 to the motive unit 17,

the plane of the frame 7, i.e., a plane containing the

members

5 and 6, can be adjusted relative to the ground plane, i.e., the plane of the skis 2 and 3, and therefore, the proportion of the weight of the skier 1 applied in the vertical direction to the motive unit 17 with respect to the amount of weight of the skier 1 carried by the skis 2 and '3, can be adjusted, the greater the angle of the plane of the frame 7 with respect to a line perpendicular to the ground plane the smaller the vertical component of force applied to the motive unit 17.

3 The weight on the motive unit l7, and hence the weight on the skis 2 and 3, can also be adjusted, even when the skier is in motion, by movement of the skiers torso forward or backward with respect to the skiers waistline,

as indicated in dotted lines in FIG. 2. Furthermore, it will be noted that as the grade up which the skier is being propelled increases, the weight on the motive unit 17'will increase, which is desirable, and the weight on the skis 2 and 3'will decrease, if the angle of the frame 7 with respect to the direction of movement is maintained constant.

The motive unit 17 comprises an endless track 19 having cleats 20 for biting into the snow, and the track 19 is supported by pairs of

sprockets

23 and 23a and 24 plus a sprocket similar to sprocket 24 but in line with the sprocket 23a having teeth extending through openings in the track or belt 19. The sprockets are mounted on

shafts

21 and 22, and the shaft 21 is the driving shaft. As described hereinafter, the shaft 21 is interconnected with a gasoline engine 25 mounted on a cross-bar 26 of the chassis, the mechanism which interconnects the engine 25 and the shaft 21 being described hereinafter. I

It will be apparent from an examination of FIGS. 1 and 2 that when the skier leans backward and rests on the band 4, on the frame 7, the motive unit 17 and the skis 2 and3 will tend to move away from each other,

the skis-.2 and 3 moving to the right and the motive unit 17 moving to the left as viewed in FIG. 2.'To limit the separation of the-skis 2 and 3 and the motive unit 17, a pair of flexible straps 27 and 28 is provided, One end of each of the straps 27 and 28 is connected to one of the side members 1.5 and 16 by loops 29 and 30 (see FIG. 6)' which are loosely received in holes at the ends of the side members and 16. Preferably, the straps 27 and 28 are secured to the

loops

30 and 29 by readily releasable. snaps so that the straps 27 and 28 can be removed from the, unit 17 when it is being carried on the back of the skier.

The opposite end of each strap 27 and 28 has an adjustable loop, such as the

loops

31 and 32, each of which preferably encircles the ankle portion of the legs of theskier. Such connection of the

loops

31 and 32 to the ankles, rather than to the skis, allows freedom for individuaL'or simultaneous, movement of the skis 2 and 3'for balancingyand/or steering purposes. However, if desired,the ends of the straps 27 and 28 remote from the endsthereof attached to the unit 17 may be fastened to the skis themselves, preferably near the skiers heels, in any conventional manner. By means of such straps 27 and 28, the skis 2 and 3 and the unit 17 are permitted to separate only to the extent permitted by the lengths of the straps 2 7 and 28, which may be adjustable-many well-knownmanner. Accordingly, the

skiers legs, the'straps 27 and 28 andtheir connection to'the lower end of the frame 7 and the frame itself" form a triangle as viewed in side elevation.

As mentioned hereinbefore, it is desirable to make the position of the frame-7 such that it is convenient for the skier to use. and such that the weight of the skier is properly distributed between the motive unit 17 and the skis 2 and 3. lthas been found that the objects of the invention have been accomplished when approximately 50 percent of the weight of the skier is borne 'by the motive unit 17 and 50 percent of the weight of the skier is borne by the skis 2 and 3, although the proportions arev variable depending upon the weight of the 4 skier, snow conditions, skis used, etc., but, generally speaking, between 40-60 percent of the weight of the skier should be borne by the motive unit 17 and 60-40 percent of the weight of the skier should be borne by the skis 2 and 3.

As illustrated in FIG. 2, the frame 7, the straps 27 and 28 and a line 33 extending from the point of intersection of the skiers body with the upper portion of the frame 7 to the point of engagement of the straps 27 and 28 with the skiers legs, preferably form approximately an equilateral triangle, so that the angle 34 between the line 35 extending perpendicularly to the ground plane and the frame 7 would be approximately 30, and the angle 36 between the line 35 and the line 33 would also be approximately 30. Thus, the angle between the frame 7 and the ground plane is approximately 60.

The respective angles, and the weight distribution between the unit 17 and the skis 2 and 3, are, of course, variable by adjusting the length of the straps 27 and 28, by adjusting the length of the

members

5 and 6, or by adjusting the position of the band 4 on the

members

5 and 6. Of course, the angles will also vary with the height of the skier and the point at which the band 4 engages the body of the skier, but it will be apparent that with normal skier sizes, the angles can be adjusted to the desired values by adjusting the length of the straps 27 and 28, the position of the band 4 on the

members

5 and 6, or the portion of the body of the skier which is engaged by the band 4, the length of the

members

5 and 6 normally being kept the same for different skiers. For example, it has been found that the length of the

members

5 and 6 may be approximately 30 inches for i almost all conditions when the distance from the pivot points of the sockets l3 and 14 to the ground contacting portion of the track 19 is approximately 6 inches.

As an example of the numbers involved, let it-be assumed that the skier weighs 180 lbs., his-center of gravity being along the line m in FIG. 2, that the weight of the skis 2 and 3 can be neglected, that the motive unit 17 exerts a vertical force of 25 lbs, at its center of gravity 3 (FIG. 2) and that'th'e angle h of the slope is 20 Assume also that the angles of the triangle formed by the frame 7, the skiers legsand the straps 27 and 28, are each 60. Under these conditions, lbs. of the skiers weight would be supported by the motive'unit l7 and 80 lbs. bythe skis 2 and 3. The total vertical force is 180 lbs. plus 25 lbs, or 205 lbs., and the component thereof parallel to the ground plane, i.e., the weight to be driven up the slope, is 92.5 lbs.

It has been determined experimentally that the coefficient of friction for the skis on the snow may beabout 0.125 and the coefficient of friction for the motive unit 17 maybe about 0.30. Thus, the friction force to be overcome is:

' 0.125 X 80 0.30 X =47.5 lbs;

Therefore, the power required to move the motive unit 17 and the skier with his skis 2 and 3 up the 20 must be sufficient to provide a driving force of lbs. (92.5 47.5) at the desired speed. If the effective diameter of the

sprockets

23 and 23a is 6 inches, the motive unit 17 will move L57 feet for each revolution of the

sprockets

23 and 23a, and if

such sprockets

23 and 23a rotate at 225 revolutions per minute, the movement of the unit 17 would be 5.9 feet per second or approxi mateiy four miles per hour which would require 1.5

horsepower (140 lbs. X 5.9 feet per second) at the

sprockets

23 and 23a. Therefore, the engine 25 can be relatively small, e.g., an engine of about two horsepower. 7

Referring now to FIGS. 5 and 6 which show the motive unit 17 in greater detail, the driving shaft 21 drives the endless track 19 by means of the teeth on the periphery of the sprocket 23, which extend through openings in the track 19. The shaft 21 is interconnected with the output shaft 37 of a centrifugal clutch 38 mounted on the output shaft 39 of the gasoline engine 25 by means of

sprockets

40, 41, 42 and 43 and

chains

44 and 45, the various sprockets and shafts being mounted on the chassis of the unit 17 in any conventional manner.

The centrifugal clutch 38 is of a conventional type which disconnects the output shaft 39 of the engine 25 from the clutch output shaft 37 when the rotational speed of the shaft 39 is below a predetermined level, such as 500 revolutions per minute. However, when the rotational speed of the shaft 39 increases above such value, then the output shaft 37, and hence the shaft 21 and the track 19, are driven by the engine 25 causing the unit to be propelled to the right as viewed in FIGS. 5 and 6.

The engine 25 is a conventional gasoline fuelled engine having a carburetor, and the rotational speed of the shaft 39 is controlled by controlling the carburetor through a cable 46 (FIG. 1), one end of which is held by the skier. Thus, when the apparatus is at rest with the engine operating at low speed, the motive unit 17 will remain stationary and when the skier desires to be propelled by the unit 17, he pulls on the cable 46. It will also be apparent that when the skier desires to stop, or if he falls, the cable 46 will be released, stopping the movement of the unit 17.

In the preferred embodiment of the invention illustrated, the frame 7 can be used for the purpose of carrying the motive unit 17 on the back of the skier as illustrated in FIG. 3. Thus, the frame 7 serves the dual purpose of supporting the skier while he is being propelled on skis, and of supporting the motive unit 17 on I the back of the skier. The frame 7 is shown in enlarged perspective in FIG. 4, and it comprises a second flexible band 47 which bears against the back of the skier when the frame is in the inverted position shown in FIG. 3. A pair of

adjustable shoulder straps

48 and 49 are securedat one end to the cross member 9 and at their opposite ends to the

portions

10 and 11 of the

tubular members

5 and 6. The motive unit 17 is supported from the frame 7 by means of the

loops

29 and 30 which are placed over the ends of the

tubular members

5 and 6 as illustrated in FIG. 3.

In one embodiment of the invention corresponding to the embodiment illustrated in the drawings in which the engine 25 was a 2 /2 horsepower engine, the entire apinches wide. In such embodiment, steel and aluminumwas used for the chassis of the motive unit, and it is believed that the weight of the apparatus can be reduced to at least as low as 22 lbs. (12 percent of the weight of a lb. skier) by use of lighter metals, such as magnesium alloys, for the chassis, and by the use of a lighter, more compact reducing drive between the engine 25 and the shaft 21.

Although a preferred embodiment of the present invention has been described and illustrated, it will be understood by those skilled in the art that various modifications may be made without departing from the principles of the invention.

What is claimed is:

1. Apparatus for propelling a skier on skis over snow and of a size capable of being supported on theback of a skier comprising:

a self-contained motive unit for supplying propulsive energy for said apparatus, said motive unit comprising an endless track means engageable with the snow, a motor, means interconnecting said motor and said endless track for driving said track by said motor and means for mounting said motor and said interconnecting means on said track means;

a longitudinally rigid frame .pivotally connected at one end to said motive unit and extending upwardly therefrom and in the direction of propulsion, said frame having means at the other end thereof for receiving and supporting a portion of the body of a skier spaced from his skis and thereby propelling said skier on his skis;

and means secured at one end to said motive unit and engageable at the other end thereof with the skier or his skis below and spaced from said portion of the skiers body for limiting separation of said skis and said motive unit.

2. Apparatus as set forth in claim 1, wherein said means'for receiving and supporting a portion of the body of a skier comprises means for receiving a portion thereof intermediate the knees and neck of the skier and said means for limiting separation of said skis and said motive unit is engageable with the skier or his skis below the knees of the skier.

3. Apparatus as set forth in claim 2, wherein said frame comprises a pair of spaced rigid members extending from said one end of said frame to said other end thereof and said receiving and supporting means comprises a flexible member extending between said spaced members and adapted to receive a portion -of the body of the skier intermediate the thighs and shoulders of the skier and wherein said limiting means comprises a pair of spaced, adjustable and flexible members, each having at said other end thereof portions for encircling a leg of the skier.

4.'Apparatus as set forth in claim 1, wherein said interconnecting means comprises a centrifugal clutch operable to interconnect said motor and said track, for driving the latter, when the speed of said motor exceeds a predetermined number of revolutions per minute.

5. Apparatus as set forth in claim 1, wherein said frame includes a pair of rigid members extending from said one end of said frame to said other end thereof and spaced from each other transversely of the length of said frame, at least one further rigid member extending between and connected to said pair of members for maintaining the latter in spaced relation, said pair of members are connected at said one end of said frame by readily releasable means to permit easy detachment of said frame from said unit, and further comprising first securing means at said other end of said frame for -7 securing the latter to the body of a skier, and second second for securing a portion of said frame spaced from said other end of said frame to the back of a skier comprising strap means attached to said frame for receiving the shoulders of a skier.

6. Apparatus as set forth in claim 5, wherein said limiting means comprises means for securing said motive unit to said frame when the latter is secured to the back of a skier.

7. Apparatus as set forth in claim 1, wherein said mounting means comprises a chassis mounted on said track, wherein said frame comprises a pair of rigid tubular members spaced apart a distance substantially equal to the width of said track and extending from said one end of said frame to said other end thereof and said frame is pivotally connected to said unit by a pair of sockets pivotally mounted on said chassis, one socket being mounted on said chassis at one side of said track and receiving an end of one of said tubular members and the other socket being mounted on said chassis at the other side of said track and receiving an end of the other of said tubular members, and cross members extending between and connected to said tubular members for maintaining them in spaced relation and wherein said receiving and supporting means comprises a band of flexible material extending between said tubular means at said other end of said frame.

8. Apparatus as set forth in claim 7, further comprising belt means at said other end of said frame for securing said other end to the body of a skier.

9. Apparatus as set forth in claim 8, further comprising flexible strap means attached to a portion of said frame spaced from said other end thereof for securing said last-mentioned portion to the shoulder region of a skier.

10. Apparatus as set forth in claim 9, wherein said limiting means comprises a pair of flexible strap means and a pair of attaching means, one of said attaching means being movably secured to said chassis at one side of said track and the other of said attaching means being movably secured to said chassis at the other side of said track, each of said strap means having one end thereof secured to an attaching means and the other end thereof formed into a loop to receive a leg of a skier.

11. Apparatus as set forth in claim 10, wherein said attaching means are engageable with said frame when the latter is on the back of a skier for securing said motive unit to said frame.'

Claims

1. Apparatus for propelling a skier on skis over snow and of a size capable of being supported on the back of a skier comprising: a self-contained motive unit for supplying propulsive energy for said apparatus, said motive unit comprising an endless track means engageable with the snow, a motor, means interconnecting said motor and said endless track for driving said track by said motor and means for mounting said motor and said interconnecting means on said track means; a longitudinally rigid frame pivotally connected at one end to said motive unit and extending upwardly therefrom and in the direction of propulsion, said frame having means at the other end thereof for receiving and supportinG a portion of the body of a skier spaced from his skis and thereby propelling said skier on his skis; and means secured at one end to said motive unit and engageable at the other end thereof with the skier or his skis below and spaced from said portion of the skier''s body for limiting separation of said skis and said motive unit.

2. Apparatus as set forth in claim 1, wherein said means for receiving and supporting a portion of the body of a skier comprises means for receiving a portion thereof intermediate the knees and neck of the skier and said means for limiting separation of said skis and said motive unit is engageable with the skier or his skis below the knees of the skier.

3. Apparatus as set forth in claim 2, wherein said frame comprises a pair of spaced rigid members extending from said one end of said frame to said other end thereof and said receiving and supporting means comprises a flexible member extending between said spaced members and adapted to receive a portion of the body of the skier intermediate the thighs and shoulders of the skier and wherein said limiting means comprises a pair of spaced, adjustable and flexible members, each having at said other end thereof portions for encircling a leg of the skier.

4. Apparatus as set forth in claim 1, wherein said interconnecting means comprises a centrifugal clutch operable to interconnect said motor and said track, for driving the latter, when the speed of said motor exceeds a predetermined number of revolutions per minute.

5. Apparatus as set forth in claim 1, wherein said frame includes a pair of rigid members extending from said one end of said frame to said other end thereof and spaced from each other transversely of the length of said frame, at least one further rigid member extending between and connected to said pair of members for maintaining the latter in spaced relation, said pair of members are connected at said one end of said frame by readily releasable means to permit easy detachment of said frame from said unit, and further comprising first securing means at said other end of said frame for securing the latter to the body of a skier, and second second for securing a portion of said frame spaced from said other end of said frame to the back of a skier comprising strap means attached to said frame for receiving the shoulders of a skier.

11. Apparatus as set forth in claim 10, wherein said attaching means are engageable with said frame when the latter is on the back of a skier for securing said motive unit to said frame.