US3338589A - Ski sled - Google Patents

Description

Aug. 29, 1967 P. M BARTON ETAL 3,338,589

SKI SLED Filed March 12, 1966 4 Sheets-Sheet l J II 23 50 INVENTOR. 1 Patrick M. Barton Henry Lefever ATTQRNEYS g- 29, 1967 P. M BARTON ETAL 3,338,589

SKI SLED 4 Sheets-Sheet 2 Filed March 12, 1965 v 3 m w wgm d MKW MYQ mm 0 9 PH /M f g 1967 P. M. BARTON ETAL SKI SLED 4 Sheets-Sheet :3

Filed March 12, 1965 \L INVENTORS Patrick M. Barton Henry Lefever aw z/a ATTORNEYS g- 29, 1967 P. M. BARTON ETAL 3,338,589

SKI SLED Filed March 12, 1965 4 Sheets-Sheet 4 Fig. 20

IN VENTORj Patrick M. Barton Henry Lefever R j ATTORNEYS United States Patent 3,338,589 SKI SLED Patrick M. Barton, 8143 Brooks Drive, Arvada, Colo. 80002, and Henry Lefever, Rte. 2, Longmont, Colo. 80501, assignors to said Barton and said Lefever, jointly Filed Mar. 12, 1965, Ser. No. 439,374 Claims. (Cl. 280-21) This invention relates to sleds, and more particularly to ski sleds of the general type which have adjustable runners for controlling the direction of movement of the sled. Accordingly, the invention will be called a ski sled and also will be referred to simply as a sled.

A primary object of the invention is to provide a novel and improved ski sled which is adapted to move along any selected course and be easily steered and controlled by tipping the edges of the runners into the snow surface.

Another object of the invention is to provide a novel and improved ski sled having adjustable runners adapted to tip into the snow surface to control the direction of movement of the sled, wherein the runners shift and.

adjust responsive to lateral shifting of the passengers body weight in a manner which is correlated with the natural balancing reflexes of the passenger, to permit him to turn the sled by leaning into the turn, as he would do in any turning vehicle to balance the centrifugal forces on his body.

Another object of the invention is to provide a novel and improved ski sled especially adapted to traverse a sloping side hill, the sled having adjustable runners which tip into the snow surface at the uphill side of the slope to eliminate downhill side slip, all responsive to lateral shifting of a passengers body weight in a manner which is correlated with the natural balancing reflexes of the passenger to hold the sled level as he moves across a sloping hillside and to maintain an upright posture in the same manner he would do if he were traversing the slope on skis.

Another object of the invention is to provide a novel and improved ski sled having individually shiftable runners which resiliently support the sled body and which are especially adapted to absorb shocks and to minimize the bouncing of the sled as it moves over a rough and irregular snow surface.

A further object of the invention is to provide a novel and improved ski sled having individually adjustable runners which shift to control the sled movement responsive to the shifting of the weight of the passenger on the sled, all in a manner which most nearly correlates the controlling of the sled by the natural balancing reflexes of the passenger and as such simulates the natural movements of a skier when turning, traversing a slope, or skiing over rough surfaces.

Other objects of the invention are to provide a novel and improved ski sled which is a simple, neat-appearing, low-cost, rugged and durable unit having considerable appeal to that segment of the public who participate in snow sports and desire to supplement skiing by sledding in a more versatile manner than now possible.

With the foregoing and other objects in view, all of which more fully hereinafter appear, our invention comprises certain constructions, combinations and arrangements of parts and elements as hereinafter described, defined in the appended claims and illustrated in preferred embodiments in the accompanying drawing in which:

FIGURE 1 is a plan View of a two-passenger sled constructed according to the principles of the invention.

FIGURE 2 is a side elevational view of the sled illustrated at FIG. 1.

FIGURE 3 is a front end elevational view of the sled.

FIGURE 4 is a front end elevational view of the sled with passengers thereon, with the sled being tipped as in turning in a curve and with a front portion of one runner being broken away to better illustrate the manner in which the edge of the runner bites into the snow when the sled is leaned sidewise.

FIGURE 5 is a front end elevational view of the sled, similar to the showing at FIG. 4, but without the passengers thereon, and with the sled traversing a hillside, the sled being leaned into the hillside to hold the body in a nearly horizontal position.

FIGURE 6 is a longitudinal sectional view as taken from the indicated line 6-6 at FIG. 1, but on a somewhat enlarged scale and with bro-ken lines indicating alternate positions which a sled runner may take when the sled is being tipped and when it is traveling over an irregular snow surface.

FIGURE 7 is a transverse sectional elevational view as taken from the indicated line 77 of FIG. 2, but on an enlarged scale.

FIGURE 8 is a transverse sectional elevational view, as taken from the indicated line 88 at FIG. 2, but on an enlarged scale.

FIGURE 9 is a fragmentary sectional detail as taken from the indicated line 99 at FIG. 6, but on a greatly enlarged scale.

FIGURE 10 is a fragmentary sectional detail as taken from the indicated line 10-10 at FIG. 6, but on a greatly enlarged scale.

FIGURE 11 is a fragmentary sectional detail as taken from the indicated line 1111 at FIG. 6, but on a greatly enlarged scale and with portions of the rod being broken away to conserve space.

FIGURE 12 is a plan view of the portion shown at FIG. 11.

FIGURE 13 is a side elevational view, similar to FIG. 2, but illustrating a modified embodiment of the sled constructed according to the invention and with broken lines illustrating an alternate position a runner may taken when the sled is in use.

FIGURE 14 is a plan view of the sled illustrated at FIG. 13.

FIGURE 15 is a front end elevational View of the sled illustrated at FIG. 13, but with the front portion of a runner being broken away to show constructions otherwise hidden from view.

FIGURE 16 is a fragmentary sectional detail as taken from the indicated line 16-16 at FIG. 15, but on an enlarged scale.

FIGURE 17 is a fragmentary detail View, partly in section, as taken from the indicated line 17-17 at FIG. 6.

FIGURE 18 is a fragmentary detail view, partly in section, as taken from the indicated line 18-18 at FIG. 12, but on an enlarged scale.

FIGURE 19 is -a fragmentary view, similar to a portion of FIG. 16, but showing another alternate construction thereof.

FIGURE 20 is a fragmentary view, similar to a portion of FIG. 17, but showing another alternate construction thereof.

The present invention was conceived and developed to provide a sled especially capable of being easily maneuvered to make turns and to traverse a sidehill slope without side slipping out of the curve or downhill. The improved sled comprises, in essence, a sled body having skitype runners mounted upon resiliently shiftable arms extending beneath the body. Each runner is restrained against twisting and turning, but it may move towards or away from the sled body in a longitudinal plane normal to the body surface as the passenger shifts his body weight sidewise.

This effects tipping of the sled with respect to the snow surface to cause the edges of the runners to bite into the snow to prevent side slipping, in the same manner as a skier uses the edges of his skis. At the same time an upturned, flared front portion of each runner facilitates pulling the sled into a curve on a fiat surface and in holding it in line when traversing a slope. In both instances, the passengers body weight shifts and tips the sled according to natural reflex movements, as into a curve to counteract the centrifugal force of his body weight or into the side of a hill to keep an upright posture and keep the body of the sled level. Each runner is also permitted to tip and rock in the longitudinal plane of its movement with respect to the sled body to minimize jolting action when sledding over a rough snow surface.

Referring more particularly to the drawing, a first embodiment of the sled is illustrated generally at FIGS. 1 to 3, its operative principles are illustrated diagrammatically at FIGS. 4 and 5, and its details of construction are further illustrated at FIGS. 6 through 12. This sled S includes a fiat, elongated body B which is shiftably supported upon up-right arms A. A pair of ski-type runners R support the arms with each being in a normal longitudinal alignment at each side of the sled. This unit is illustrated as being a two-man sled and the seats are conveniently located to form housing members for certain of the arms A.

The body B is a lightweight, longitudinally-extended rectangular frame formed by longitudinal bars at each side and at the center, which are held in spaced parallelism by transverse frame bars 21. These traverse bars 21 include front, intermediate and rear members located at suitable positions for holding the arms A. The longitudinal frame bars 20 are preferably lightweight, circular tubular members, while the transverse bars 21 are preferably larger, rectangular, tubular members having a width and height sufficient to permit the bars 20 to extend through holes in the sides of each bar for interconnection therewith, as shown, and other passageways through which the arms A extend, as hereinafter described.

Seats 22 are provided at an intermediate and rearward position on the sled. Each seat is formed with a flat seating portion 23 which extends across the longitudinal frame bars 20 and is secured thereto by clamps 24 and an upright backrest 25 which overlies and is secured to a transverse bar 21 by clamps 26. Each seat 22 is preferably a preformed member of fiberglass or like material and the backrest portion is hollow to receive and protectively encase arm portions extending through openings in the transverse bar, as illustrated at FIGS. 6 to 8. When the body is adapted to hold two passengers, the front seat is positioned to permit its passenger to rest his feet upon the front transverse bar 21 between the side frame bars 20. For the convenience of the rear-seat passenger, a foot rest 27 may be provided on each side bar 20, as in the manner illustrated at FIGS. 1 and 4.

The arms A are upright rods which extend through openings in the transverse frame bars 21, as illustrated. the arms are arranged as a pair of groups with each group, at a side of the sled, supporting one runner R. Each group includes a forward arm 30, an intermediate arm 31 and a rear arm 32. The forward and rearward arms and 32 are resiliently-mounted, load-supporting members while the intermediate arm 31 is a restraining, guide member adapted to keep the runners R in their proper position underneath the sled.

To connect the arms to the runners, each arm is formed with a transversely-disposed tubular bearing 33 at its base. The bearing 33 is carried upon a shaft 34 which, in turn, is mounted between the ears of a flat yoke 35, as clearly illustrated at FIG. 11. Each yoke 35 is affixed to the top of its runner R at its proper forward, intermediate or rear location on the runner, as by mounting screws 36,

with the axis of the shaft being parallel with the runner contact surface and transverse to the longitudinal axis of the runner. Accordingly, when the arms A are held in position, the movement of the runner R is restricted to pivoting about the axes of the shafts 34 and to movements in the direction of the vertical, longitudinal plane of symmetry of the runner as they move towards and away from the body of the sled.

The freedom of movement of the runner R is further restricted by the manner in which the arms are held on the body B. Each restraining guide arm 31 extends upwardly from its centrally positioned mounting on the runner and through orifices 37 in the top and bottom of the intermediate transverse frame bar 21. It is held in a position normal to the horizonal plane of the body by a pair of spaced bearing sleeves 38 secured above and below the frame bar 21 as by bolts 39. This intermediate guide arm 31 is formed as a rigid rod which telescopically slides in the sleeves 38 to hold the runner directly underneath the sled body and to resist longitudinal and side thrusts against the runner. Accordingly, the guide arm 31 is a comparatively strong member; however, the bearing sleeves 38 are preferably of a self-aligning type to prevent a binding action which could otherwise be caused by elastic flexing of the arm 31 as in the manner indicated by the broken line a at FIG. 10.

The forward and rear load-supporting arms 30 and 32 respectively, are substantially identical in construction. Each extends through an orifice 40 at the underside of its supporting bar 21 and through an enlarged opening 41 at the top side of the bar. Each is slidably held in a selfaligning bearing sleeve 42 which is bolted to the underside of the frame bar 21 by opposing bolts 43 which have hooks 44 upstanding from the bottom surface of the bar 21 and into the interior portion of the bar, to hold supporting springs as will be described.

Each supporting arm 30 and 32 extends upwardly from the deck surface of the body B to carry tension springs for supporting the body on the arms. In the illustrated arrangement, a double-crossbar 45 is secured to the upper portion of each arm as by a connector bolt 46 held in a mounting orifice 47 in the arm and extending through an orifice 47' in the cross bar 45. One end of a spring 48 is attached to each side of the cross bar 45 as in an orifice 49 in the bar, and the other end of the spring is connected to the hooks 44 attached to the frame bar 21. The springs are of a proper stiffness to support the loading imposed on the sled body and an array of orifices 47 are positioned along the axis of each arm to permit the cross bar 45 to be shifted and provide for height adjustments of each end of the sled.

It is to be noted that the upwardly projecting portions of the rear arms 32 are encased within the upright seat back 25 of the rearward seat, and that the upwardly projecting portions of the restraining guide arms are protectively encased within the forward seat back 25. The upwardly projecting portions of the forward arms 30 are illustrated as being exposed; however, it is contemplated that a suitable protective housing, not shown, may upstand from the sled body over the forward transverse frame bar 21. It is also contemplated that other arrangements may be used to enclose the upwardly projecting portions of the arms A whenever a different sled type is used, as where three or four seats are provided, such being within the contemplation of the invention.

The sled runners R are each formed as an elongated ski-like member, each having a longitudinally extended body 50 which has a flat, rectangular cross section and an upcurved, flared head 51. The side contact edges 52 of this head diverge at the upturn to provide lateral turning leads adapted to grip the snow whenever a runner is tipped sidewise in the snow. It was found that not only would such heads facilitate turning the sled, but that they would also facilitate holding the sled in position when traversing a steep sidehill.

To complete the unit, the sled is equipped with a braking system 53 such as that illustrated at FIGS. 2 and 9. A hand lever 54 is mounted upon each side frame member 20 at a position where it may be easily gripped by the rear passenger when he is riding the sled. Preferably, the lever is arranged to retract the brake when it is gripped and to extend the brake to stop the sled when the lever is released. Each lever connects with a full wire 55, encased within a tubing 56 and extends to the top of a tubular brake head 57 near the rear end of the runner. The head 57 includes a flange 58 at its base for attachment to the runner R. A drag cylinder 59 is carried within the head to project from the underside of the runner. This drag cylinder 59 is connected to the end of the pull wire 55 extending into the top of the head 57 and is thereby adapted to be pulled upwardly into the head 57 whenever the head lever is pressed. At the same time, a spring 60 within the head bears against the drag cylinder to resiliently urge it downwardly and below the runner whenever the head lever is released.

In use of the improved sled, it is to be noted that the combined restraining effect of the arms holds the runners below the sled body in such a manner as to limit the runner movements with respect to the sled body to two degrees of freedom. Each runner may move towards and away from the sled body, and it may rotate about a transverse axis parallel to the body. Such movements are illustrated in broken lines at FIG. 6. However, these restricted movements provide natural guiding controls of the sled simply by shifting the passengers weight from one side of the sled or the other in accordance with the passengers natural reflexes. Whenever a sled is to commence turning, the passengers will lean into the turn to counteract the centrifugal force of their body weight. This shifting causes the inner runner to move towards the body of the sled and to tilt the sled as in the manner shown in FIG. 4. This tilting causes the diverging contact edges 52 of the runner heads 51 to bite into the snow and commence a turn. A similar result is obtained when the sled is traversing a hillside. The natural tendency is for the passengers to tip the sled body into the hillside to hold the deck of the body level, as illustrated at FIG. 5. This causes the uphill runner to' be moved towards the sled body and the side edges of the runners to bite into the hill slope.

A' further desirable action is obtained whenever the sled is traversing a rough snow surface, for each runner may tip and tilt independently of the other, with the springs 48 acting as individual shock absorbers, the movements of an individual runner being indicated at FIG. 6 in broken lines.

An alternative embodiment of the present invention is illustrated at FIGS. 13 through 20. In this construction, the sled S is mounted upon runners R by arms A which are pivotally connected to the runners R and also to the underside of the sled body B. Accordingly, the arms A of each runner are articulated to swing in the longitudinal vertical plane of the runner, as hereinbefore described, and also the connections to the sled hold this plane of movement normal to the surface of the sled as will now be described.

The body B is formed as a rectangular frame having side members 20 and end members 21. These members support a deck surface which is illustrated as a woven webbing W, with the sled being especially adapted to support a single passenger riding it in a prone position. It is to be understood, however, that other variations of the deck structure are easily possible with this arrangement.

The arms connecting each runner to this body B include a forward arm 61 and a rear arm 62, each of which connect with a side member 20' of the sled, as hereinafter described, and extend therefrom rearw-ardly and downwardly at an approximate angle of 45 degrees for a pivotal connection on the upper surface of the runner to which it is attached. Each arm is preferably formed as a channel-like member having a flat web section 63 transversely disposed with respect to the longitudinal axis of the sled, and flanges 64 at each side thereof. The lower end of each arm A includes bearing orifices 33 in the flanges 64, through which a transversely disposed shaft 34 extends. This shaft is carried in a yoke 35 aflixed to the top surface of the runner as by holding screws 36, the same as hereinbefore described.

A lift spring 65 associated with each arm is adapted to hold the arm at a selected inclination, approximately 45 degrees, when the sled is supporting the weight of a passenger. This spring 6-5 is wound about the shaft 34 with one extended end 66 abutting against the underside of the arm web 63, and the other extended end 67 abutting against the upper surface of the runner, as shown at FIG. 16. A balanced, doubled arrangement of the spring is accomplished by using a doubly-wound member with the spring being folded at the end 66 to form a socket 68. A threaded washer 69 is secured in this socket to hold an adjusting screw 70 to shift the inclination of the arm 61, or 62, as desired.

The upper end of the rear arm 62 is directly connected to the frame member 20 above it. The upper end is formed with a cut-away portion of the web 63 to provide extended flange portions 64', each having an orifice forming a bearing 71 to receive a transverse shaft bolt 72. This bolt also extends through diametrical opposed orifices 73' in the longitudinal body member 20', and suitable spacer washers 74- are positioned between the flange ends 64 and the tubular body member 26, all as clearly illustrated at FIG. 18.

The front arm 61 is slidably connected to the frame member 20' by means of a collar 74. This arm is formed with a cut-away web portion 63 at the top to provide flange extensions 64". These extensions 64" are olfset adjacent to the web to be spaced from the body member 20' to better embrace the collar 74. The collar 74 is a simple tubular sleeve slidably carried upon the body member 20'. It includes diametrical opposing flat surfaces 75 whereagainst the arm extensions lie. Each arm exten sion is secured to the collar 74 by a pivot nut 76 having a shaft portion 77 fitting in a bearing orifice 78 in the arm extension 64", and a threaded stub 79' turned into threaded sockets 80 in the collar 74.

With the above described arrangement, it is manifest that the runners may move towards and away from the body of the sled B by pivoting of the arms 61 and 62, although this movement is accompanied by a comparatively insignificant amount of longitudinal shifting of the runner with respect to the body. Also, the runners may tip from a normal position parallel with the longitudinal body members 20, shown in full lines at FIG. 13, to an inclined position, shown in broken lines at FIG. 13, by the sliding of the collar 74 upon the member 20". Accordingly, the sled may be operated precisely the same as the sled S, as heretofore described.

FIGURE 19 shows a spring arrangement for holding modified arms 61' and 62' at the selected inclination. A portion of an arm 61 is illustrated as being mounted upon a shaft 34 on a yoke 35, as heretofore described. The modification consists of a spur 81 outstanding from the pivoted end of this arm 61 to connect with a tension spring 82 secured to the runner R by a clip 83. Adjusting means, not shown, may be included in this arrangement, and the functional operation of this arrangement is the same as that heretofore described.

A further modification to insure stability of the sled in rough use is illustrated at FIG. 20. As shown at FIGS. 13 through 18, the longitudinal body member 20' may be conveniently formed as a circular tube, and lateral rigidity of each runner R is assured by the manner in which the shaft bolt 72 connects the upper end of the rear arm 62 to the frame member 20'. This type of stability is not possible with the front arm 61 because the collar would rotate on the member 20. Should such stability be required, however, the forward end of the body member 20 may be modified to a square section as by fillets 83, and a square-sectioned collar 74' may slidably lit the body member over the filleted portion of the body member to prevent rotation of the arm about the axis of the body member 20.

We have now described our invention in considerable detail; however, it is obvious that other skilled in the art can build and devise alternate and equivalent constructions which are nevertheless within the spirit and scope of our invention. Hence, we desire that our protection be limited, not by the constructions illustrated and described, but only by the proper scope of the appended claims.

We claim:

1. A ski sled comprising:

(a) a body formed generally as an elongated, ,flat

structure wherethrough a reference plane may be extended which is substantially parallel to a supporting surface when the sled is set thereonwithout being loaded;

(b) a longitudinally-extended runner underneath each side of the body having a flat undersurface, normally parallel with said reference plane with the runners being adapted to. support the sled upon the snow;

(c) a plurality of posts upstanding from each runner in a longitudinal array and being pivotally connected thereto by pivot means having their axes transversely disposed and parallel to the undersurface of the runner and to said reference plane;

(d) a plurality of guide means at each side of the body in a longitudinal array through which the posts slidably extend, said guide means being adapted to restrict movements of the posts, and the runner attached thereto, to a longitudinally-disposed plane normal to said reference plane, one of said guide means at each side of the body being rigid to hold the post extending through that guide means substantially normal to said reference plane, and the other guide means at each side of the body being rotatable about an axis transverse of the longitudinally disposed plane, whereby to permit each runner to move towards and away from the body and to tip with respect to the body within said restricted plane and without twisting of the runner about its longitudinal axis and without frictionally binding the posts within their respective guide means whenever a runner is tipped with respect to the body; and,

(e) a supporting means associated with the posts adapted to support the body above the runners, but to permit the runners to be moved towards and away from the body responsive to shifting of the weight of the passengers on the sled.

2. In the organization set forth in claim 1, including a forward, center and rear post on each runner, with said guide means being adapted to hold the center post normal to said reference plane and being adapted to permit the forward and rear posts to tip in said longitudinal plane normal to the reference plane and thereby permit the runner to tip about a transverse axis parallel to the said reference plane.

3. In the organization set forth in claim 1, wherein the means adapted to support the body above the runners include springs adapted to yield responsive to the shifting of the Weight of the passengers on the sled.

4. rganization set forth in claim 1, wherein said runners vormed with upturned, outflared leading ends adapted tdIffacil itate turning of the same.

5. In the organization .set forth in claim 1, wherein said guide means ingl'tiifdeself-aligning bearings mounted upon the body through which said posts slidably extend and wherein the supporting meansfi inoltade a cross arm upon the extended end of a post and springs extending therefrom to the body.

References Cited UNITED STATES PATENTS 3,173,703 3/1965 Isenberger 280-25 XR FOREIGN PATENTS 173,615 1/1953 Austria. I 803,852 7/1936 France. 1,039,069 5/1953 France. 1,074,921 4/ 1954 France.

923,474- 2/1955 Germany. 453,644 12/ 1949 Italy.

BENJAMIN HERSH, Primary Examiner. M. S. SALES, L. D. MORRIS, Assistant Examiners.

Claims (1)

1. A SKI SLED COMPRISING: (A) A BODY FORMED GENERALLY AS AN ELONGATED, FLAT STRUCTURE WHERETHROUGH A REFERENCE PLANE MAY BE EXTENDED WHICH IS SUBSTANTIALLY PARALLEL TO A SUPPORTING SURFACE WHEN THE SLED IS SET THEREON WITHOUT BEING LOADED; (B) A LONGITUDINALLY-EXTENDED RUNNER UNDERNEATH EACH SIDE OF THE BODY HAVING A FLAT UNDERSURFACE, NORMALLY PARALLEL WITH SAID REFERENCE PLANE WITH THE RUNNERS BEING ADAPTED TO SUPPORT THE SLED UPON THE SNOW; (C) A PLURALITY OF POSTS UPSTANDING FROM EACH RUNNER IN A LONGITUDINAL ARRAY AND BEING PIVOTALLY CONNECTED THERETO BY PIVOT MEANS HAVING THEIR AXES TRANSVERSELY DISPOSED AND PARALLEL TO THE UNDERSURFACE OF THE RUNNER AND TO SAID REFERENCE PLANE; (D) A PLURALITY OF GUIDE MEANS AT EACH SIDE OF THE BODY IN A LONGITUDINAL ARRAY THROUGH WHICH THE POSTS SLIDABLY EXTEND, SAID GUIDE MEANS BEING ADAPTED TO RESTRICT MOVEMENTS OF THE POSTS, AND THE RUNNER ATTACHED THERETO, TO A LONGITUDINALLY-DISPOSED PLANE NORMAL TO SAID REFERENCE PLANE, ONE OF SAID GUIDE MEANS AT EACH SIDE OF THE BODY BEING RIGID TO HOLD THE POST EXTENDING THROUGH THAT GUIDE MEANS SUBSTANTIALLY NORMAL TO SAID REFERENCE PLANE, AND THE OTHER GUIDE MEANS AT EACH SIDE OF THE BODY BEING ROTATABLE ABOUT AN AXIS TRANSVERSE OF THE LOGITUDINALLY DISPOSED PLANE, WHEREBY TO PERMIT EACH RUNNER TO MOVE TOWARDS AND AWAY FROM THE BODY AND TO TIP WITH RESPECT TO THE BODY WITHIN SAID RESTRICTED PLANE AND WITHOUT TWISTING OF THE RUNNER ABOUT ITS LONGITUDINAL AXIS AND WITHOUT FRICTIONALLY BINDING THE POSTS WITHIN THEIR RESPECTIVE GUIDE MEANS WHENEVER A RUNNER IS TIPPED WITH RESPECT TO THE BODY; AND, (E) A SUPPORTING MEANS ASSOCIATED WITH THE POSTS ADAPTED TO SUPPORT THE BODY ABOVE THE RUNNERES, BUT TO PERMIT THE RUNNERS TO BE MOVED TOWARDS AND AWAY FROM THE BODY RESPONSIVE TO SHIFTING OF THE WEIGHT OF THE PASSENGERS ON THE SLED.

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