US2339886A - Motor toboggan - Google Patents

Description

J` R. SHANNON MOTOR TOBOGGAN Jan. 25, 1944.

Filed May 12, 1941 s shets-sheet 1 r r f f Jan. 25, v1944.

J. R. sHANNoN MOTOR ToBocvrGAN Filed May l12. 1941 5 'Sheets-Sheet 2 INVENToR JEP/v f?. JHHN/vo/v AJM, MMM

, ATTORNEY;

Jan. 25, ,1944. .1, R. SHANNON MOTOR ToBoGGAN Filfed May 12, 1941- 3 Sheets-Sheet '3 Patented Jan. 25, 1944 UNITED sin;ci"'Esv rrrsu'r OFFICE Application May iz, 1941,v serial No. 393,045

21; Claims.

This invention relates to improvemexfuzs4 in mof tor toboggans. f

It is the primary object of the invention topwvide a motor toboggan withl a propulsion cl'evtccl operating on a new and improved principle@- to s deliver considerably increased traction with much reduced power consumption. In` thisfoninection it is my object to substantially reiieveV the propulsion device of the mere` dead weight ofv the vehicle or its occupants and',v instead; to apply to the propulsion device pressure which. is concentrated at the rear of the transverse line thereof so that the propulsion devicek has* a climbing action as distinguished from' the mere endless track operation of a conventional.` tractor` or tank. It is further my purpose to provide means' whereby the downward' pressure onf-the propulsion device may be concentratedon either end thereof, according to the direction of.' movement'. of the vehicle and to provide in' conjun'c- 20 tion therewith means for reversing the: motion of the propulsion device and means whereby the vehicle is enabled to function in reverse:

A further object of the invention: s-t'o providel a: novel and improved frame structureffor a pulsion device, with a novel arrangementaior maintaining the` propulsiond-evioe under' nominal pressure andvproviding for the increase of suchA pressure at the.. desired. endi of' the-pro pulsion device by supplementar` manualpressure. when desired. fr

It is aiurther` object of the invention toiprovide a novel and improvedsupporting: runner structure which, instead-i ofv beingl` maderelativelic rigid as heretofore,.made1 extremelyfil ble,v thereby further" improving the efliciency of its: operation and minimizing the: resistance-#fof obstacles encountered by the vehicle: en.- lrr thus increasingthe exibilityA olil'tle runner structure it is my purpose incidentallytapro de' for exibility of4 all controls and. oonnectlonsl- Another object of' the invention; iste; pro de snow lubrication for-the steering-sltiandtth K' porting runner and'4 t'osolocatethe; pivo of steering ski as' tomake' thel ski' self-rect tol a forward steering position after* it has;

turned. y

A further object is generally` to simplify a improve the construction, arrangementand erationV for one or morev of the purposes-I me tioned, and still other objects willlfliel appareil from the specification- This: applicationv is a companion teitlie-fappliicationof Carl`A J El Eliasonl forl nt'ediStatels Batters Patent onpropulsionL meclinisxnfuif "Sir 1 engine I1.

motor toboggans, filed May4 12, 1941, Serial No.

393,053', and issued as PatentNo. 2,323,526, July 6; 1943, said companion application embodying some of the features hereinafter referred to.

1inl the drawings: l 'f Fig. 1. is a view in side elevation of a motor toboggan embodying the improvements I claim.

Fig. 2 is a view 0f the motor toboggan in plan.

Fig. 3 is an enlarged detail view of the propulsion mechanism partially' in side elevation and' partially in. section.

Fig. 4 isV an enlarged detail view'of the motor toboggan in cross sectionA on'` the line `4---4'y of Fig. 12

Fig. 5` is a fragmentary detail view in plan. of the endA of the propulsion mechanism shown in Fig. 3;

Fig. 6, is an enlarged fragmentary detail in. perspective showing a portion of the vpropulsion conveyor and associated track parts;

Fig; 'I is an enlarge-dv detail view in perspective of. oneofi the conveyor cleats shown in a position inverted from the position; which the cleats are illustrated in Fig. 6. 1

Fig.A 8 isl an enlarged fragmentary detail view plan of the interior surface of the propulsion conveyor shown in Fig. 6.

Fig.` 9`isv a fragmentary detail view in plan of ,the forward seat support, thef-seat being partially broken away to expose the support.`

Figs. 10 and 11 are: viewsinL transverse section onlthei side elevation of a modied forward seat supportl- Fig. 12 is a` fragmentary-detail in perspective 'I otliatportion of thev supporting runner structure, immediately at the. rear of the-,engine mounting,

Likeparts are identified the same reference: characters throughoutthe. several views.

The. device has for itsy fundamental support aisled'geor. toboggan structure. generically designatediby vreference character L5. Atits forward eudLthe/sledge or toboggan structure I5 has at I'If a continuous, full-width, toboggan-like portion upwardly curved as shown in Fig. 1. Mounted' upon this toboggan-like forward end is the Rearwardly of thev engine the entire central area ofthe sledge is. open between a pair of laterally spaced ski-like runners I8 and W ('Fig; 2)` which are rearwardextensions of the forward toboggan surface ISL Between the runners I8. and I9 the rear margin of the toboggan surface I6 is turned upwardly at I'6, while the: rear' ends of the runners" .themselves are tumedupwardlyat |80 and I'9'0". These upwardly turned portions at the rear of the supporting surfaces only represent a portion of the arrangements which make it possible for the device to be propelled under power rearwardly as well as forwardly.

The runners I8 and I9 are joined in uniformly spaced relation by a series of brackets 20, 2 I, and 22, all of which are made as shownin Fig.l4, comprisingv vertical, legs 23 terminating i'n` laterv ally projecting feet 24 secured to the respective runners I8 and I9 and joined, well above the runners, by a supporting bar 25 upon which-the` padded seat board 26 is mounted.

The forward toboggan portion I of the sledge` l is provided with cross cleats, across two of whichthe engine I'I is connected. To avoidrigidifyi'n the sledge the engine is made fast -only to the E rearmost of the cleats upon which it rests.; Throughout its length, the entire sledge, in-

cluding the toboggan portion I5 at its front" end' and the longitudinally extending supporting runners I8 and I3, is extremely flexible. In this regard it differs from previous devices of the type in which the seat and its mounting .and the engine and its mounting have somewhat rigidied the runners. i

,. In the present apparatus the seat board 26 `(itself flexible if desired) is connected rigidly only with` bracket-20. Where it crosses brackets 2|and 22 to receive support therefrom, the connection is such as to permit free `movement be- -tween the seat and the supporting bracket. This kis done either in the manner shown in Fig. 1 and Fig. 9, or in the manner shown in Fig. '10 and kFig.`11. In Fig. 1 and Fig. 9 the bracketsll .and 22 are provided with slotted. arms-,21. and the bolts 28 connected to the seat board 2,6 are :free to move in the slots of said arms. In the construction shown in Figs. 1l) and 11 the bracket 22 has upwardly` extending arms at 29 `from :which pivoted'links.,290 suspend the seatl board.

Ineither case'the seat has such free movement `withrespect to the supporting brackets as to permit of great flexibility in the runners.

' This represents. a new concept of the function oflthe runners. vParticularly in crosscountry travel through deep snow, the machine is frequently` called upon to traverse falln logs,

stumps,`stones,and other obstacles. The sledge,.

including the front toboggan surface andthe runners, carries the weight somewhat as a boat carriesits load in water. The softer the supporting snow, the deeper the runner surfaces will sinkinto the snow untily the Weight is sustained. However, if the 'runnersurfaces are operating in relatively deep snow and a submerged obstacle is encountered, the functioning of the vpresent 'devicejdiffers" from the operation of a boat in that'a/'boat is rigid Vand must in its entirety rise to clear the submerged yobstacle whereas the present device, due to its great flexibility, will yieldv Yto the obstacle while -only slightly-supportedlby the obstacle and elsewhere supported still by the snow.l l As a result, the ,imlactis greatly reduced andthe power greatly reduced.

Steering is effected'thrcugh manipulation of a pair of ski-like runners 30 and 3|, individually pivoted to the forward section I6 of the supportingsledge by king- pins 32 and 33 respectively.I The runners 30 and 3| may be held in parallelism f by a link 34 at their forward ends, and they. may be` steered in any desired manner as by -means of the lever 35 connected to king-pin l3Iland acdemands are tuated by link 36 from an upright hand lever 38 (Fig. 2).

The steering skis 30 and 3| taper rearwardly in thickness. 5 clined slightly downwardly at the rear, while their under surfaces are inclined upwardly at the rear as indicated at 3| I. Their king-pins 32 and -v33 are l,located forwardly of the center of the '-eii'ectiv vContact surfaces tomake the skis tend tostraighten themselves, during forward propulsion, after a turn has been made.

A washer 3| 2 is interposed between each of the skis 3| and the sledge. While this might be thought objectionable, in that any increase in {dimensions embeds the steering skis more deeply 'the'fshow, it has been found that the space provided by such a washer, together with the f `space provided by the rearward tapering of the upper surfaces at 3|0, greatly facilitates steering "zoby--permitting snow to accumulate between the .steering skis and the under side of the Sledge, such snow acting as a lubricant. Wooden surfaces are .very freely movable with respect to each otherwhen snow intervenes. The upward inclination of th under surfaces of the respective skis at 3||l permits the vehicle'to be operated in reverse, 'which is a major advantage when it is Y necessary to turn it around in limited space, i a Power from engine II passes through a transmission case 39, preferably containing a reverse gear `v(not. shown). Power output is delivered by sprocket Illto a chain 5| which drives sprocket :L 52.,l on .tubular shaft 53 at the forwardV end of a `sub-f1fua11f1e 55.for the propelling mechanism herel-inafter to be described.- The engine supporting means-includes a rear bracket 56, to which the engine is` pivotally connected, and a forward lbracket-Mill (Fig. 1 and Fig, 2), fromfwhich the ,engineis flexibly suspended by links 56|. j 0, A pair of links 51, adjustable as to length for ,the purpose of tightening chain 5|, and cross connecteduto move in unison, are pivoted co-axially with pinion 4|] to brackets 5I0vrigidly connected .to the transmission case. At their rear ends these links are pivoted to the sub-frame by means oftheA pintle bolt 58 upon which the tubular shaft 53 is-rotatably mounted. The links 51 transmit the-l thrust of the propulsion device to the .toboggan while permitting the propulsion, device in its entirety to have Afreedom of vertical movement with respect to the toboggan. The.- sub-frame is preferably a truss-like structure provided at each side with upper and lower guide members 60 and 6I (Figs. 3 and 4) 55 spaced'at. suitable intervals by vertical posts 63, 64 and 65. l Upper and lower guide members 6|) 'and-61 are preferably made of wood, but the posts 63,64and 65 are made of metal diagonally braced by-metal tubesfwelded thereto as best Asl'iowndn--'F igs.l and 3. i L The trussv'like structure comprising 'the 'posts 5163, 64 and 65,-the diagonal tubular bracing, and the toma-nd bottom guide members of wood, is a novelorganization particularly developed for this machine... lIt is'strong and yet has the necessary degree of flexibility and at the same time the metal cleats of the track hereinafter tobe described move freely over the wooden guide memb ers l6|) and 6I without freezing thereto andwith 30.. practically no resistance due to a provision of .means hereinafter mentioned, whereby snow-may be' trapped in recesses of the'cleats for lubrication. .between the metal cleats and the wooden guide. members. The wooden guide members are 15 readily;V replaceable, being detachably -bolted to Their upper surfaces 3|0 are inthe; posts to whichthe, diagonal bracing: isf welded;

At the forward end of the sub-frame the driv- 'ing tubular shaftSS carries taz-pair'offsprockets 6 1 and;` 63' over which. operateichains.: 69 arrdfV 7.9" for vwhich sprocketsV 'Il are rotatably,r mountedr on shaft 12a at the rear' of" the. propulsion. sub@- frame 55'.

Adjacent the. driving sprockets attheiforward end of the sub-frame, and also adjacentthe,idling sprockets at. the rear'end ofv the subi-frame; the

4wooden guide members 6U' and B l" are preferably curved inwardly to-ward the=axesofl the-- several -sprocketsas best shown in Fig. 3:

Spanning the space between the guide :members in the manner best shown` in Figsli: and 5;-are

cleats T5, preferably of' the.formrbestillustrated in Figs. 6 and 7. At each end; eachcl'eat 15 has the general form of an angle iron with.' anormally horizontal fla-nge F91 anda normally' vertical flange V5 The-horizontal flange: hasar groove rvor channel 'iS-in cnet-face; suchi face having sliding bearing contact. with therwooden guide: members ASily and 61 of the sub-frame. In practice .the

groove orV channelSLwill catch snowand pac-k' it to form an icy supportupon*which-theA -cleat'will 'ride' upon the wooden: guide-surface;V The ice or 'packed snow which willv collect' in such a channel :Willi move over the. wooden guide surface with practically no wearl whatever;

The cleats havel ears- 19 spaced toreceive.y the respective chains. The space betweenethechains is spanned by: an intermediate portion of each cleat in which the rlanger'l of'theA cl'eatiis dis.- placed to form an apex rearwardly directed' with respect to the path off'conveyor movement, suc-h apex being designated by reference character 89 in Fig. 6 and'Fig. 7.-

At opposite ends, of alternate cleats one-cfr the ears H9 is extended to provide a guide shoel 199.

'The staggered guide shoesbear'lateral-ly against the sides of the upper and lower wooden guide 4members 99 and 6l to maintain tlfle`V chainsA in alignment with the sprockets, the staggered arrangement of" the shoes permitting accurate 'alignment without cramping. regardless of expan- ,i

into the chains to.l allow snow to be forced out from between the sprocket. and theside plates of the chain so thatsnow will not-'betrapped beneath the rollers.Vv

- Held by clamp plate 9i to the inner surfaces of flanges 16 of thesuccessive cleats, is endless -belt 85 having' center slack betweensuecessive cleats to form deep pockets as indicated,at-t5,r the depth of which should preferablycbetwo or three times the height ofthe-unangei portions. li; of: the jcleats. When the device is operating., in soft snow the snow is penetrated not only by' vthe anges il of the-cleats, but` aisov by the entire conveyorv system to the: full: depth. permitted: by the pockets at of thebelt 85. Asi eoresult, considerably increased-traction is aiorded and :at the same time the propulsion is more efficient', less power beingwasted.

, As best shown in Fig; 4, Vthere is a guideway between the: runnersA I8 and i9 in: whichy the entire sub-frame 55 and the conveyor.n system mounted thereon is, movable upwardly andv downivvardly between the legs..23 ofthe ushaped bracketfwhichsupnprts tha-seat-fZB. AThefsub; frame. and; corr,vermel systeme. arav biased-1, down#` wardly not; only bmgravity but bythe compres; sion of the springs 81 and 8,8:l which action rock shafts 891.and, 89,91 respectively, these being-r provided withv suitablabearingson the sub-drame and, provided witharms Sil-and; 9i secured; by

The. downiward bias provided bythe springs 81 and 89 may be supplemented. by: manual pressure exerted through a hand lei/ter: 95 oscillatableY about the axis of-rockrshaftilil.l

The'arms190farefastupon the rock shaft 89 but the hand lever4 9534s.. free ofthe shaft and?` does not operate the arms 99 except insofar as motion is' transmitted"I to the'shaft and to the` armsv 9.0 by meansfofiafnger9ll0 mounted'on the hub-901| to which the-handlever 95is connected, as best show-n in IEig-.v 4f. When the hand 1ever'95 is pushed manuallyy in. a clockwise direction as viewed in Fig. 1, the finger 99|] engages the arm Whichthereuponfacts'as anvextension of hand lever Beingd'xed byv link. 92,r the compound lever exertsrdownwardpressure on the sub-frame of the: propulsivamechanisml at rock shaft 89,

which is well'to the rear of the transverse cen'- ter line of fthe sub-frame.- This forces the entire propulsion mechanism to an inclined position in- :dicated' in1 dottedlines'in` Fig. 1, the exact angle propulsion mechanism will readily climb onto the snow and graduall'ycompact it with-out pushing the snow` ahead of the conveyor system inthe manner previouslyexperienced. It is found that the effectiveness and: efliciency of the vpropulsiva mechanism in termsf of` its traction effort are very marked-lyvv increased by this diierential application ofY pressure. under manual controly to that.` end of.l the propulsion system which isl at therear. v

However, such-manual application ofipressu-re at the: point represented" by rock shaftzil would -beV Wholly-Wrongvhen the device was being operated-.in reverse.` Accordingly, the rock shaft 899 carries `looselyahubelement 89| similar to that upon which hand lever 95 is xed, such hub element having anger 892 engageable with one of the arms-9| ofrockshaft 899. This hub element is` connected-by acorn-pression link 893 to the hub elementy 9M and the arrangement is such-that when the hand lever 95- is draw-n counter-relooke Wiseby the operator, rock shaft 89 will be left idle but the motionwill be transmitted through lin-ger 892 to oscillate the. arms 9| about their connections with links92, thereby exerting. pressure downwardly on the. sub-frame 55 forwardly of its .transverseicenter line. Thisis usedirrre'.-

Aversing to produce a similar eifect during reverse traversed; The. weight is carriedv by the sledge andthe runners. As previously noted, this principle is responsible for a great increase in efiiciency of propulsion.

Where it is desired to coast, it is possible to lift the entire sub-frame. On the under side of the seat 2E are journaled rock shafts 93 and 94 connected by a link 950 and actuated by a hand lever 96 on rock shaft 93. Each of the rock shafts is provided with an arm 91. and the respective arms are connected by the exible tension elements 98 with the sub-frame, such elements having adequate slack to permit free downward' movement of the sub-frame toward the dotted line position of Fig. 1 for normal propulsion, but nevertheless being so designed that when the lever 96 is pulled counter-clockwise about the axis of rock shaft 93, the entire sub-frame and conveyor system can be lifted clear of the supporting surface, leaving the vehicle free to coast.

Fuel and oil are preferably carried in the tank at the forward end of the vehicle seat, such tanks being connected by suitable flexible pipes IOI and |02 to the engine. A hand lever |03 is connected by link |04 to a, bell crank connected with the gear shift lever |05 ofthe engine, while the clutch lever |06 of the engine is operated by link |0'I from clutch pedal |08. A similar pedal at |09 on the runner I9 operates the throttle lever |I0 or other speed control of the engine.

As explained above, the whole supporting surface of the sledge is hi-ghly flexible. It is this flexibility that makes it necessary to provide ilexible pipes for fuel and oil and to accommodate relative movement in all of the various control levers. The pivotal connection of link |04 from hand lever |03 to the bell crank which actuates the gear shift is made in substantial alignment with the aXis upon which the engine pivots in the flexing of the runner system, thereby minimizing the effect of such flexing upon the position of hand lever |03. The throttle pedal |09 has less freedom of movement, due to its short length, but the linkage which connects it to the speed control lever on the engine passes approximately through the axis upon` which the engine is pivotally mounted, and consequently there is very little displacement of the throttle pedal when the runners flex,

The gear shift or transmission of the engine includes a reverse mechanism which, being conventional, is not illustrated in detail, the present application being concerned only with those features of the device which make it feasible to operate it in reverse, and the particular gearing connections being conventional.

In deep snow it is necessary, or at least desirable, .to provide for considerable accuracy of balance. The center of gravityof the motor I'I is conveniently placed materially to the right of the center line of the toboggan.

The c enter line of the toboggan is indicated at C in Fig. 2, while the center line of the engine is located at D.

In order to equalize or balance the load upon the runners I8 and I9, the seatiis disposed materially to the left of the center line of the toboggan looking forwardly inFig. 2, the center line of the seat being indicated at A. The oiset to the left is well illustrated in Fig. 4, where it appears at the right hand side and Where it will be observed that the foot 24 of one of the supporting legs 23 of bracket 20 is so placed as materially to overhang runner I8, whereas the vother foot 424 does not Iso greatly overhang beyond the edge of runner 9.

This offset of the bracket legs 23 with respect to the' runners I8 and I9 brings the propelling conveyor center line to a position where it is slightly offset from the center line of the toboggan as a whole, as indicated at B. The center line of the seat is even farther offset, as indicated at A in Fig. 2.

In normally forward propulsion in soft snow, forv which the vehicle is particularly adapted, the propulsion conveyor and sub-frame will normally depend at the approximate angle illustrated in dotted lines in Fig. 2.

The amount of resistance to displacement which is offered by snow will be increased according to the amount of snow engaged by the traction surface of the propelling conveyor. Accordingly, the pockets provided by the bagginess of the belt between successive cleats of the conveyor system are of great assistance in increasing propulsive effort. The device is capable not only of carrying all of the men who are able to ride upon the seat 26, but also capable of towing behind it several heavily loaded toboggans.

When a hard surface is encountered by the cleats, the shock of impact is materially reduced by the Wedge-shaped disposition of the flanges 'I5 at 80. Such shock is further reduced by the fact that the cleats are rigidly supported only at their ends upon the lower wooden guide members 6| which, with the whole sub-frame, 'are free to yield. While the sub-frame has considerable Weight and inertia and does not yield readily, the fact that the intervening portions of the flanges 'I'I-of the cleats are not directly supported is of great value in reducing shock upon impact -with a stone or icy surface, particularly at high speeds.

With the improvements herein described, the chains are self-clearing and do not accumulate ice. Moreover, they are so guided between the -wooden members 60 and 6I that they are no longer dependent upon the sprockets for guidance, but are held by the guide members in the proper alignment with the sprockets.

Iclaim:

1. In a device of the character described, the combination with a sledge having supporting runners, of a propulsion mechanism bodily movable vertically respecting the sledge and bodily tiltable in a vertical longitudinal plane and including an endless track between said runners and floating with said mechanism for bodily vertical movement at both ends of said mechanism respecting said runners, freely responsive manually operable lever means for actuating the track, and means for applying downward pressure to said propulsion mechanism nearer to one end than to the other.

2. A device of the character described comprising the combination with supporting runnersgof substantial width whereby to be adapted to operate in deep snow, a propulsion mechanism disposed between said runners and comprising a floating sub-frame vertically movable bodily respecting said runners, link means pivoted to the sub-frame and to the runners for transmitting propulsion from said mechanism, rotors mounted adjacent the ends of said sub-frame to partake of the bodily vertical movement of the sub-frame respecting the runners, an endless propulsion track operating over said rotors, means for actuating `said track, and lever means freely responsive to operator manipulation for exerting a downward pressure upon the subfirame at a. point nearer theefmntend thereoiaandtoeiorcasaidConverter the rearward end thereof than therforwardiend 'consacrate 'nj snow een. anlupward,finclinevrethereof as viewed `from thev standpoint rof .thefdi-f smelling Sadfsllla:N/bhQU-rplellldillg:ite lQajf rection of propulsion. `tenc le.r1l\,. 'itoselfffconformation with a hard 3. `In a device of the character describedfthe 52 Suraeblfaverse@ combination with supporting runner means,of, 7. 'ff-@11; @M0319 Ye Yhle.;.thescombnatm endless track propulsion means, a floatingsube Wit/1.1,.zslllpolitingmeansV adapted.- ov sustainj'the f and highly, :flexible linea lungi.

frame upon which said propulsion means.,is mounted and vertically movable respecting the; runner means, both ends being free: for self-.ad- 1 0' justment in conformity with the surfacetravf ersed, driving connections for the propulsion means, linkmeans pivoted to the subi-'frame and the supporting runner -means for `the;'.transl'nssion of propulsion through the runnervmeans while accommodating bodilyiioating movement of the sub-frame, means for biasing' saidfsub-f; frame and propulsion means bodily downwardly respecting said runner means, and means include ing a lever constantly dependent onand subject, 2n highly," to an operators control for increasing the down? ward bias to which one end of said 'subgiramej is subject. f. 4. In a device of the character described, the combination with runner means, of endlesstr ck propulsion means provided with outwardlyedri ing connections, sub-frame means bodilytiltable: in a vertical longitudinal plane and upon whichu said endless track means is operatively mounted',;A mechanism connecting said sub-trarne` means vrto said runner means for bodily Vrelative vertical movement, and mechanism constantlyy dependent on manual control for inclining said Sub-frame' means and said endless track means upwardlyat its forward end with respect to said runnerY means. r 5. A device of the character described2corn, prising the combination with a toboggan.surfaceL adapted to receive support substantially,hori- `V zontally in soft snow, of a propulsiondevice come prising a floating sub-frame and-anendlesscona, veyor operable thereon and provided with,,-snow., engaging track means, a link connecting said subframe with said toboggan surface for thetransf mission of traction thereto, said sub-framebeing bodily movable vertically with respect to saids face, biasing means spaced longitudinallypfs sub-frame and exerting dowrnzvard.v `llirs thereon with respect to said surface,vv andan acn tuating device including a freely movable leverr'gr` dependent on manual control for its position operatively connected with one offsaid'bias means for augmenting the bias tliereof"` wher neateds 0 b an engine supports;

@estrema pra-f ng endless conveyor nel trask meahsrand. a .sube ,h r reigns ,over Whichsaicl cop- Y :e said sulfi- S- I L. ariel 'g fthe, .Gema

to incline said propulsion device with respect or IlS-CQQS for Unir/e3 ngthe bfQIi-saidsub-frame said surface and to press one end otsaidgprd-w pulsion device more deeply than th'elr'gther,ir'r't'riA snow traversed by said surface. A i 6. A vehicle comprising the combination with, a supporting surface adapted to, sustain the hiclein soft snow, of an engine mounted ons surface, a seat carried by said surfacema float propulsion device comprising an endlessconve having snow engaging track means ,and a ub frame .having rotors over which said conveyoriigsz makerriguid sub-framefuni bearings 1a, Q end operable, link means connecting the subeframeI with the vehicle for the propulsion offthe vehicle, said link means permitting said sub-frameand7 conveyor bodilyvertical movement n respecting said wooden said surface, driving connections from said enthe aforesaid `vcurved ends' of the wooden.guide gine to said conveyor, a lever adjacent said seat, 70 members being disposed adjacent the rotors to and biasing connections from said lever to said pick up said traction devices as such devices leave sub-frame operable thereon at a point nearer the the rotor.

rear than the forward end of the sub-frame 11. The combination with vehicle runner whereby to dierentially bias the rear end of the means, of floating sub-frame means, endless tracrear frame downwardly with more pressure than 75 tion conveyor means operable upon said subrrame means, a reversible driving Vconr'ietion to said conveyor means, and a selective biasing mechanism provided with selectively operable donnee#` tions constantly dependent for position i-up'onmanual operation for exerting downward bias on saidsub-frameimeans at either end thereof.

1'2."The combination with supporting runner structure, of sub-frame means mounted for ver-y tical and tiltingV movement respecting said runner structure,traction conveyor meansoperable over-said sub-frame means, biasing means dis; posed at points longitudinally spaced on said subframe means for the bias thereof downwardly respecting said runner means, and lever means constantly dependent for its biasing eifect upon manual operation and provided with connections to the respective biasing means for the selective operation thereofto augmentl theirbias. --13. The device of the claim 12 in whichthe biasing means comprise rock shafts mountedon the lsub-frame and having arms linked to therunner means, and said lever means has fingers `selectively engageable with'the arms of differing roel; shafts in 'they diifering directions of lever movement forfvactuating the rock shafts in thev same direction in which they are biased by said biasing means, said biasing means includin springs acting upon said rock shafts.

14.- A vehicle `oi`- the character described comprisingva forward toboggansurface and lateral runners comprising-1 ski-like rearward extensions ofV said surfacas'aid forward toboggan surfacey being upwardlycurved at its forward end and havingy an upwardly curved portion between saidl runners at its rearwardend and said-runnersv beinglikewise upwardly curved at their rearwardends remote from'said tobogganportioma pro-f pulsiondevice disposed-between said runners; andV po'wer operated means for the actuation ofsaid' device in either direction', together withjmeans for selectively exerting downward blas'upon either` end'of said propulsion `'device for inclining it up` wardly with respect toeither direction of vehicleV movement.

`A-vehicle of thecharacter described 'com-1" prising the-combination with asupporting runner surface, of a steering-runner pivoted beneath said surface and upwardly curved, thel pivotal-.con-

nection of *said runner with saidv surface disposed forwardly of-jthe centerof the effective supporting area -"of said runner whereby saidsteering runnenis substantially self-straighten?? ing-afterbeing'fturned for steering. f

-16. .en` Vautomotive snow-traversing. ,vehicle comprising the combination with a-ftoboggan of arpropulsion device comprising anendless'conf veyor having tractionfrmeans thereon, an engineY operatively connectedH to actuate said conveyor'l and mounted oir-said toboggan with its center ol" gravity at' one side 'of the longitudinal centerline of the toboggan, a seat mounted on said toboggan andsufficientlyV offset at the other side ofsaid center line sothat the occupants of-said seat tend tobalance theweight-of the engine about the longitudinal centerline of- Vsaid toboggan. 'the center line of the traction means of said'propub siondevice being disposed between the center line of theseat and thecenter of gravity of thev kengine.vi.. .A

las

`1v. A vehicle of the character described com pris'ing the combination with elongated flexible snowtraversing supportingmeans, of an engine sub-frame both ends of which are independently movable vertically respecting said runner means, guides near the respective ends of the sub-frames, an endless Vpropulsion belt operating over said guides, a rotor connected with one of said guides for fthe actuation of said belt, a second rotor mounted upon said runner means and connected withfsaid prime mover, an endless driving means operating over the respective rotors for the transmission of motion from the prime mover on said runner means to the propulsion belt on said subframe,v and a link pivoted to the sub-frame near the axis of the rotor mounted thereon and pivotedfto said vehicle near the axis of the rotor mounted thereon, whereby to `ma intain approximately constant tension on said endless driving means while accommodating full iloatingxmovementof said sub-frame andA propulsion belt respeting said runner means.

lilrlThe device of claim 18 in further combination with means exerting a downward bias from said- `vehicle upon said sub-frame while accommodating floating bodily movement of said subframe vertically respecting the runner means and also accommodating bodily tilting movement of said 'sub-frame. I

20.1,"I'he device of claim 18 in further combination with means exerting a downward bias from saidfyehicle upon said sub-frame while accommod'ating floating bodily movement of saidsubfr'anevertically respecting the runner means and also accomniodating bodily tilting movement of saidv sub frame,vsaid biasing means including a spring v'constantly operable upon said sub-frame, and a lever/dependent foriits' biasing eifect upon,

manual operation:

2i.- The deviceof claim 18 in' further combina-- tionjwith means exerting a ,downward bias from' said 1vehicleupon said sub-frame while accommodatingiloating bodily `movernent'of said subframe vertically respecting the runner means andiV alsglfaccommodating bodily tilting movement 'of saidfs'ub-frame, said biasing means rincluding a spring constantly operable upon said sub-frame and a lever dependent for its biasing effect upon manual operation, saidrlevercomprising manually-selectively operablev connections whereby the bias of said lever `is applicable 4selectively to press downwardly on eitherend of said sub-,frame to adegree manually determinable in the manip...

ulation'of the lever.

JEAN R. SHANNON.

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