NOV. 26, 1946. p_ E_ HAWKlNs 2,411,570 STEERING GEAR FOR VEHICLES Filed Nov. 27,_ 1943 5 Sheets-Sheet l ’ w‘ \ g v /. / PAUL E-HAWKINS. my 5 Nov. 26, 1946. P. E. HAWKINS 2,41 l ,570 STEERING GEAR FOR VEHICLES . Filed Nov. 27, 1943 11,114,111‘ :s Sheets-Shéet 2 Nov. 26, 1946. P. E. HAWKINS 2,411,570 STEERING GEAR FOR VEHICLES Filed Nov. 27, 1943 ‘s Sheets-Sheet 5 _ FIG. 9 BY M Patented Nov. 26,1946 2,411,570 UNITED STATES PATENT OFFICE 2,411,570 ‘STEERING GEAR FOR VEHICLES Paul E. Hawkins, Lakewood, Ohio, assignor to '\ The Baker-Rauiang Company, ‘Cleveland, a corporation of Ohio Ohio, Application November 27, 1943, Serial No. 511,997 12 Claims. (01. 280-787) This invention relates to wheel-mounted ve hicles, more particularly to the steering gear mechanism therefor. The invention is particular ly applicable to motor driven vehicles, although it is not to be limited to vehicles having a motor 5 traverse paths about a common ‘center during turning movements of the vehicle. Another object of the invention is to provide in a vehicle having a pair of dirigible supporting wheels, improved connections between these or pneumatic type) and the pavement or road in Another object of the invention is to provide in a vehicle having a pair of dirigible supporting "and powered thereby. ’ , wheels having an automatic compensating or In all vehicles employing a pair of dirigible differential mechanism operable to position the wheels to e?ect steering thereof, of ‘which I have dirigible wheels in di?erent angular relation for knowledge, operation of the vehicle along curvi steering the vehicle whereby in each steering po linear paths has caused slippage between the 10 sition these wheels traverse paths about a com treads of‘ the tires (whether of the solid, cushion mon center. directions laterally of or at angles to the plane of each wheel, such‘ slippage resulting in wear on wheels, improved connections between the the tire treads, stresses on the wheel mountings 15 dirigible mounted wheels and related to the axis as well asiwear of the pavement or road; and ob of the non-dirigible wheel or wheels, operable in viously th’ese disadvantageous conditions are in any steering position of the dirigible wheels to creased in proportion to the weight of the vehicle eiTect traverse of all of the supporting wheels and its load. This wear takes place to a greater ‘ about a common center. extent on the tires' for the dirigible wheels as 20 Another object of the invention is to provide compared to the non-dirigible wheels of the ve in a vehicle having at each end thereof a pair of hicle, for which reason it is customary to shift the tires on the wheels. Also, greater wear takes dirigible mounted wheels, improved connections between each pair of wheels operatively connected place on the tires of vehicles having shortened to simultaneously swing all of the wheels and ar wheel bases and/or narrowed treads as compared 25 ranged to ‘ell’ect differential movement of the to tires on vehicles having'long bases and/or wide wheels of each pair, whereby all of the wheels in treads. each steering position thereof traverse paths While such wear may be reduced to a limited extent by maintaining perfect alinement of the about a common center. Other objects of the invention will be apparent wheels and adequate pressure in the tires (if 30 to those skilled in the art to which my invention pneumatic tires are used), such wear is always relates from the following description taken in present due to the fact that when the dirigible wheels are operated about their respective trun ' nions or steering knuckles, they as well as the other supporting wheels for the vehicle do not traverse paths concentric to a common center. One object of'the invention is to provide an improved steering mechanism for a wheel mount ed vehicle wherein wear on the wheel tires due to slippage thereof in steering .the vehicle is 40 eliminated. connection with the accompanying drawings, wherein ‘ Fig. l is a side elevation of a vehicle embodying Q my invention. Fig. 2 is a plan view showing'the wheels for the vehicle and steering gear. Fig. 3 is a fragmentary view of the steering gear, enlarged. ' Figs. 4 and 5 are sections on the lines 4-4 and 5-5, respectively, of Fig. 3. Another object of the invention is to provide Fig. 5a is a fragmentary plan view of parts in a vehicle having dirigible supporting wheels shown in Figs. 2 to 5, inclusive. improved connections between them for simul Figs. 6 and 7 are diagrammatic views illustrat taneously swinging the wheels about their respec 45 ing the method of relating the steering connec tive knuckles into di?erent angular relation, tions to the steerable wheels; Fig. 6 also showing whereby the wheels traverse paths about a com in dotted lines one steering position of the steer mon center to effect steering of the vehicle. able wheels. Another object of the invention is to provide Fig. 8 is a plan view (partly diagrammatic) in a vehicle having one or more non-dirigible 50 showing a modi?cation wherein all four wheels supporting wheels and a pair of dirigible sup of the vehicle are steerable. porting wheels, improved connections between the latter wheels for simultaneously swinging '_ them about their respective knuckles into di?er Fig. 9 is a section on the line 9-9 of Fig. 8 In the drawings, I indicates as an entirety a vehicle embodying a steering gear ashereinafter ,ent angular relation, whereby the dirigible wheels 55 set forth. The vehicle I shown for illustrative 2,411,570 ' 3 . common center or centers which lie in the axis a. The differential mechanism I3 comprises the following; I4, 14a, indicate a pair of links pivot ally connected at their outer ends to the outer ends of the arms 8, a connector I5 pivotally con nected to and arranged to ?oat between the in elevating mechanism 4 are non-steerable and power driven and the driver’s station 5 is,also adjacent to and faces the elevating mechanism 4, so that the wheels 2 may be referred to as the front wheels and the wheels 3 may be referred to as the rear wheels. It is to be observed that in industrial trucks it is the practice to provide 4 wheels 2, 3, will always traverse paths about a purposes is of the industrial type having a pair of power driven wheels 2, dirigible steering wheels 3 and a suitable elevating mechanism 4. In the arrangement shown the wheels 2, adjacent the ' _ ner ends of the links and guides I6, IGa, for con " trolling the movement of the connector I5. The 10 link I4 is pivotally connected on an axis 1) at its inner end to the connector l5, whereas the inner ‘ dirigible steering wheels at either end of the-truck , end of the link No is pivotally connected on an axis b’ to the connector I5 at one side of the axis irrespective of whether it embodies an elevating b of the pivotal connection of the link I4 with mechanism and also to position the driver's sta tion remotely from the elevating mechanism or 15 the connector I5, the axes b, b’ preferably being in a plane parallel to the planes of the wheels what may be termed the front end of the truck. Since the improved steering gear herein disclosed ‘ 2, 3, whenrthe latter are in normal position for vehicle travel in a straight line forward or back is applicable to all wheel mounted vehicles and ward, and the connector I5 is provided with a vehicles having front or rear steerable wheels, such disclosure is merely illustrative of the pre 20 device I‘I (preferably consisting of a stud shaft provided with a roller I193) which is disposed lat ferred application of the invention. erally of the plane intersecting the axes b, b’, and The wheels 3 are mounted On suitable spindles has pivotal and slidable engagement with the op 3a, having knuckles pivoted on pins 8 mounted posed walls of the guide I6. By preference, the in the opposite ends of the axle ‘I and integrally connected steering arms 8 preferably extending 25 connector I5 consists of a bell-crank having a short arm I5a, which is disposed parallel to the forwardly from the axle ‘I. The axle 'I is con wheels 3 when the latter are in normal position, nected in a well known manner to the vehicle and a long arm I5b preferably disposed at right frame by springs ‘Ia. One spindle knuckle is pro angles to arm I5a, the link I4 being pivotally vided with an arm 9, the outer end of which is connected by a stud shaftv I4’ on the axis b to the connected by a rod Ill to a suitable gearing I I, the bell-crank at the angle between its arms I5a, 15b, latter in turn being connected through the steer so that the lever arm I5b forms, in effect, an ing column IIa to an operating member, prefer extension of the link I4, and the lever arm I‘Sa ably consisting of a wheel I2, whereby the arm serves as a connection between links I4, Illa, 9 may be operated to effect steering, as later set 35 whereby the power transmitted from the wheel forth. I2 through the arm 9 and adjacent arm 8 to the I3 indicates as an entirety a differential or com link I4a will move the link I4 substantially end pensating mechanism connected to the arms 8 wise but differentially as later set forth. The and arranged, upon operation of the wheel I2 outer end of the short lever arm I5a is provided during vehicle travel, simultaneously to swing the wheels 3 in either direction into different rela 40 with a device I‘Ia (preferably a stud shaft pro tive positions, whereby the wheels 3 traverse ' vided with a roller "12’) slidably engaging the opposed walls of the guide Ilia, which preferably arcuate paths about a common center, which consists of an elongated slot extending substan center in any operated position of the wheels is tially parallel to the axle 1, formed in a plate I8, intersected by an imaginary line a extending par whereas the roller I‘Ia: on the device I‘! on the allel to the normal axis of the wheels 3, shown outer end of the long arm I5b of the bell-crank at a’ .(Fig. 6). By preference, the mechanism I3 I5 slides in the guide I6, which consists of a cam is related to the axis of the wheels 2, as later set shaped elongated slot formed in the plate I 8, forth, that is the imaginary linea is co-incident Each of the links I4, I4a, is of sectional con with the axis about which the wheels 2 rotate. Accordingly, in any turning movement of the ve 50 struction to provide for their adjustment in length endwise. The outer end of each link ter hicle, due to operation of the wheel I2, all four minates in a yoke MD to receive the outer end wheels 2, 3-, will traverse paths about a common center. Where the steerable wheels have a di ameter larger or smaller than the diameter of the non-steerable wheels (as shown), this imagi nary axis or line a will be disposed in a plane per pendicular to but above or below the axis of the of the adjacent arm 8 and likewise the inner end of each link I4, I4a, terminates in a yoke I4b’ 55 which straddles the bell-crank I5 (see Figs. 4 _ I8 5). I preferably provide two plates spaced by sleeves I8a surrounding bolts I8b, which clamp the plates in rigid relation, both plates being formed with guide slots I6, Ilia; and wheels 2; since the diameter of the wheels 3 is less than that of the wheels 2, the center of the arcuate paths traversed by the wheels 2 and 3 will 60 In this arrangement, the device I'Ia on the end lie on a line (1 below the axis on which the wheels 2 rotate. While the range of swinging movement of the wheels -3 about their respective pins 6 relative of the lever arm lid is provided on the opposite sides thereof with rollers I‘Irr' engaging the side walls of the slots Isa and the device I‘! on the lever arm I5b is provided on the opposite sides to the axis a’ (see Fig, 6) may vary, as it is cus 65 thereof with rollers Ila: engaging the side walls of the slot I6. tomary in maneuvering turns to decrease or in In the disclosed arrangement the plates I8 crease the turning radius and in bringing the are disposed on the outer side of the axle ‘I; by vehicle into a forward or backward straight di preference the inner U-bolts (also designated operation will obviously move the common center 70 I8b) which secure the springs ‘Ia to the axle ‘I are utilized to secure the plates together along for the wheels 2, 3, along the imaginary axis a, their inner sides and to rigidly mount the plates in one direction or the other, dependent on the on the axle ‘I. The plates I8 and parts there direction of swinging movement of the wheels 3, between are preferably enclosed in a suitable cas so that during any right or left turning move ment of the vehicle on a ?xed or varying radii, the 76 ing I9, which is also secured in position by the I rection of travel, such variations in the steering , 2,411,570 , b its llb, as-shown in Figs.‘ 3 and 5, the end walls always move in paths about a common center of the. casing being formed with openings or in each operated position of the wheels 3, slip cut-aways l9a (see Fig.5a) through which the page of the vehicle wheels relative to the pave-' links ll, Ila, extendto permit movement thereof. mentor road is eliminated and that therefore In view of the fact that the rollers. llx, I13’, wear on the tires due to slippage of this character are mounted on vertical axes and provided‘, with is avoided. ' s flat peripheries and the side walls of the guide |_ From the foregoing description it will be appre slots l6, l6a, are flat, the bottom wall- of the ciated that the shape of the cam slot It to con--. casing I9 is utilized to slidably support. these trol the di?erential movement of the wheels 3. rollers and inner ends of the links M, Ma, during 10 whereby in any and all operating positions for the vehicle laterally, they and the wheels As shown in Figs. 3 and‘ 5a, the guide slots. steering 2 may traverse paths about a common center, de-v 16a for the lever arm lia extend transversely of v pends on certain dimensions of the vehicle, such the vehicle, whereas the cam-shaped guidejslots as its wheel base, the treads of its wheels, the It for the lever arm libhave opposite end por length of the arms 8 and the angle thereof rel tions l6’, It", at either side of their mid or peak ative to the wheel spindles 3a and lengths of portion, the angle, of the portion l6" relative to the bell-crank arms l5a, l5b', the distance be the slots [6a being greater than that of the por tween the axes of the pins 8, also the links ll, tion l6’. When the. wheels 3 are in normal posi Ha, must be adjusted to the proper lengths. tion for forward or backward rectilinear travel 20' When these factors are known, the wheel spindles the roller I11: is at the peak positions of the" cam . 3a,‘ arms 8, links H, “a, the bell-crank I 5, a slot slots, whereby it may move ineither direction I 6.1:, the roller Hz’ in the slot Ilia: as shown in and the roller' Hz’ is disposed intermediate the Fig. '7, the roller Ila: and a line (not shown) ‘ends of the slots lGa, whereby it may move in spaced from the axle ‘I representing the axis a either direction. Accordingly, when operation of of the wheels 2 are drawn or developed on a sheet the wheel l2 to swing the wheels 3 in either di of suitable material, these parts being shown in ‘ rection takes place, for example, to the right, as normalposition (this position being illustrated indicated at C (Fig. 3), the rod Hawill transmit in full lines in Fig. 7). With the parts shown movement thereof. ' ‘ ’ ' such operation through the bell-crank l5 to the rod l4, thereby bodily moving the bell-crank and endwise moving the link l4. During such move ment of the bell-crank l5, theroller I‘Izc' moves rectilinearly transversely of the vehicle in the , guide slots l6a, whereas the roller I‘Ia: traverses in this’ relation, the position of the roller I1 is ?rst plotted to indicate the peak position of the cam guide slot. Next, the arms 8 are moved to different positions (that is, plotted on the mate rial as shown in dotted lines) to show the spindles lie on radii common to a center on the line a and the cam port-ion l6" of the guide slot I6 in a 35 the position'of the roller Ila: is then plotted on direction outwardly and laterally (the pivotal I the“ material. This plotting process is repeated connections between the links M, Ma, and bell for successive positions of the spindles 3a (three crank l5 permitting movement of the latter rela positions being shown in Fig. 7,) throughout the tive to the links), the result being that a reduc steering range for the wheels 3 at either side of ing di?erential movement of the link I 4 relative 40 the peak position. As. the diameter of the roller ‘to that of the link Hz: is effected due to the Ila: is shown, the cam slot lBx' may be. ‘plotted inclination of the cam portion 16" of the guide from .the successive positions of the axis of the slot I6, and accordingly in any steering opera roller I 1x. tion toward the right the range -of movement of It will be observed that the arm 3 may be con- . the left side wheel 3 will be less than that of 45 nected to the spindle 3a of either wheel and that the right side wheel 3. On the other hand, in the differential mechanism may be positioned any steering operation toward the left, the roller rearwardly of the axle ‘I. I12: traverses the guide slot cam portion IS’, the It will be observed from the foregoing descrip angle of which relative to‘the guide slot is less tion_that the cam slot It may be plotted from‘ than that of the cam portion l6", so that the 60 centers on any line parallel to the normal axis movement transmitted by the link Ila through a’; accordingly, in a vehicle having one or a pair the bell-crank l5 to the link [4, will effect an of rigid supporting wheels 2, if this line is for increasing differential movement to the latter ward or rearward of the axis a, only the wheels link so that the range of movement of the left 3 will traverse paths about a common center dur side wheel 3 will be greater than that of the right 55 ing steering operations. By preference the cam side wheel 3. ' slot IQ is plotted from the axis a, so that all of Fig. 6 diagrammatically shows the angular the wheels will traverse paths about a common steering relation of the wheels 3, on the radii center in the operation of the vehicle and since ‘d, d’, struck from the center :03 when the right» this plotting is on or relative to the axis a, one or , side wheel 3 is disposed at an angle of 50 de 60 a pair of non-steerable wheels may be provided grees relative to the axis a’, whereby the wheels at that end of the vehicle opposite to the steer 2, 3,, traverse paths about this center; radii e, e’, able wheels. struck from the center x2, indicate the position Flg. 8 illustrates the application of my inven of the wheels 3 when the right side wheel is , tion to a vehicle having four steerable wheels 2', swung to a 30 degreeangle relative to the axis c5 3', knuckle mounted on axles 1', 1", respectively, a’; and radii J‘, J", struck from the center :11’, as shown in Figs. 3 and 4. The spindle for one indicate the position of the wheels 3 when the of the wheels 2' and the spindle for one‘ of the right side wheel‘ 3 is swung to a 20 degree angle wheels 3' are provided with arms 9' which are relative to the axis a’. Accordingly, it will be operatively connected, as later set forth. observed that when a steering operation takes 70 I 3’ indicates as an entirety, a differential steer place,‘the compensating or differential mecha ing mechanism between and connected to the nism l3 serves to position the wheels 3 in such wheels 2’ and I3" indicates as an entirety a dif relation that they and the wheels 2 move along‘ ferential steering mechanism between and con paths about a common center. . nected to the wheels 3', each of these mechanisms It ‘will be observed that since the wheels 2, 3, 76 being similar in construction and operation to 2,41 1,570 . 7 ' ' 8 . the mechanism l3, already described, except the shape of the guides or cam slots lib, l6c, and the arrangement thereof, for which reason a de tail description of the mechanisms l3’, [3", will _ not be necessary to an understanding of the in-' 'vention and its application to the simultaneous connected to said swingable means and the other wheel for swinging the other wheel from normal position in either direction, whereby both wheels swing in the same direction when operated for steering the vehicle on curvilinear lines of travel, said connections including an intermediate con steering of fourwheels. Due to the fact that in necting element ‘operable to permit overlapping adjacent transverse .guide slot I63, is remotely related to the corresponding portion [60' of the position to effect vehicle travel on arcs about a relative movement between other velements of any steering position ,(a) the wheels 2' are swung said connections, and guides for the elements in..one direction and the wheels 3' are simul taneously swung in the opposite direction, the 10 of said connections, said connections being there by operable to automatically‘ position said swing lateral portion lib’ of the cam slot lSb, which able wheels in angular relation in any operated portion‘ has the increased angular relation to the cam slot lie and (b) the cam slots l?b, I60, are 15 common center. , ‘ 2. A vehicle as claimed in claim 1 wherein the guides consist of a cam with which the elements plotted in the manner already set forth according of said connections slidably engage. 'to centers which, in this form of construction, lie 3. In a vehiciecomprising a wheel mounted in an imaginary plane between the normal axes frame, the wheels atone end of said frame be a: of the wheels 2', 3', as indicated by the line :c'. Accordingly 'when the wheels 2', 3' are positioned 20 ing mounted to swing on substantially vertical axes from normal position in either direction for as shown in" dotted lines, they will traverse paths steering the vehicle, manually operated means about the common center 1:", and this will apply connected to one of the wheels and connections to a predetermined center in any steering position between them, said connections comprising a of the wheels 2', 3’. ‘ It will be observed that the centers about which 25 pair of transversely disposed links each pivotally connected at its outer end to one of said wheels, a separate link pivotally connected at its opposite ends to the inner ends of said links and operable the other pair, each cam slot lGb, |6c, must be to transmit the thrust or pull from one link separately plotted in the manner already set forth; however, where this line is disposed mid 30 to the other link to swing both wheels in the same direction when said manually operated way between the pair of wheels (that is,‘ their means "are operated, and means for controlling axes), as shown in Fig. 8, the cam slots will be the movement of said separate link during op similar in shape except that their lateral por eration of said manually operated means to per tions will be reversely related for reasons above set forth; accordingly only one cam slot needs 35 mit relative movement between the ends of said the wheels 2', 3', move lie on a line therebetween. Where this line is nearer one pair of wheels than to be plotted on a chart or other material for one links endwise thereof, one slower or faster than the other link dependent upon the operation of pair of wheels, as it is only necessary to turn the said wheels to either side of their normal posi chart over for determining the shape of the cam tion. slot for the other pair of wheels. The plotting is 4. In a vehicle comprising a frame, a pair of carried out similar to that already set forth, ex 40 spaced supporting, steerable wheels at each end cept that one pair of wheels only are successively of said frame, each wheel of each pair being related to centers on the plane or line a’ midway mounted to swing on a substantially vertical between the wheels 2', 3’. axis, means connected to one of said wheels of The connections between the arms 9' prefer each pair for operating it in either direction, ably consist of the following: 20 indicates a operating connections between the wheels of each housing suitably supported on the vehicle chassis pair arranged to swing both of said Wheels in and providing an elongated bearing for a trans the same direction when operated for steering verse rock shaft 20a the opposite ends of which the vehicle, said connections for each pair of are provided with cranks 2|, which normally extend in the same direction - relative to the 50 wheels consisting of links pivotally connected at their outer ends to said wheels and connecting shaft, preferably vertically upwardly. The outer means between the inner ends of said links op end of each crank 2| is pivotally connected to erable to move the latter endwise relative to each the inner end of a rod ID’, the outer end of which other during operation of said operating con is pivotally connected to the adjacent arm 9'. The crank 2| at one side is also connected to a 65 nections between said pair of wheels, whereby one wheel of each pair is caused to swing through link 22v which is suitably connected through suit a larger'angle than that of the other wheel of able mechanism in a casing 22' to a steering the pair, and operating connections between one column Ila’ having a wheel [2’. wheel of each pair of wheels and a wheel of the To those skilled in the art to which my in-‘ vention relates many changes in construction 60 other pair of wheels arranged, in each steering and widely diifering embodiments and applica tions of, the invention will be apparent without operation, to simultaneously swing' said pairs of wheels in opposite directions. 5. In a vehicle as claimed in claim 4 wherein departing from the spirit and scope thereof. is provided a cam‘ having lateral portions pre My disclosures and description herein are purely determinately related to a vertical plane parallel illustrative and not intended to be in any sense 65 to the normal axes of each pair of wheels for limiting. guiding one of' the links connected to the adja 'What I claim is: cent pair of wheels during movement thereof, 1. In a vehicle, comprising a frame and front one wheel thereof relative to the other wheel and rear supporting wheels for the frame, the of the pair, whereby said one link will swing 70 wheels at one end of said frame being mounted one wheel at a greater angle. thereon to swing on substantially vertical axes 6. In a vehicle comprising a frame, a pair of to effect steering, of the vehicle, means opera supporting wheels adjacent one end of said tively connected to one of said swingable wheels frame, an axle at the opposite end of said frame, for swinging it from normal position in either a pair of dirigibie supporting wheels mounted direction, and connections between the wheel 75 9 10 . ‘ - ,on the opposite ends of said axle, means con- ‘ said guides, a bell crank, one arm of which is nected to one of said dirigible wheels for operat ing it in either direction, arms ?xedly related to the spindles for said dirigible wheels, and push and pull connections between and con-‘ nected to said arms operable‘to swing both of pivotally connected to said device, the inner end of the other link being pivotally connected to said bell crank intermediate its ends and the " other arm of said bell crank being provided with a device slidably engaging theother guide, the last mentioned guide having lateral portions dis posed at different angles relative to said ?rst said wheels in either direction, an intermediate element of said connections being movable rela tive to the elements thereof connected to said mentioned guide, and means connected to one arms to control the movements of the last men 10 of said dirigible wheels for swinging it in either tioned elements, one. relatively faster or slower direction. than the other wheel dependent upon the direc 10. In a vehicle, the combination with a frame tion of swinging movement of said operated and front and rear supporting wheels for said wheel. ‘ frame, the wheels at one end of said frame being 7. In a vehicle comprising a frame, a pair of 15 mounted thereon to swing on substantially verti- , supporting wheels adjacent one end of said cal axes, of means operatively connected to one frame, an axle at the opposite end of said of said swingable wheels for swinging it from ‘ frame, a pair of , dirigible supporting wheels normal position in either direction, connections mounted on the opposite ends of said axle, between the wheel connected to said swinging arms ?xedly ‘related to the spindles for said 20 means and the other swingable wheel for swing-, last mentioned wheels, and differential con ing the latter from normal position in either nections between said arms operable to swing direction, whereby both swingable wheels swing both of said wheels in either direction-one rela in- the same direction when operated for steer tively faster or slower than-the‘other-wheel de-. ‘ ing the vehicle on curvilinear lines of travel, said pendent upon the direction. of swinging ih'iove as connections consisting of a pair of links disposed ment thereof, differential‘ connections consisting of a plate ?xed‘ to said axle and provided with guides, links pivotally connected attheir outer one of said swingable wheels and an intermediate ends to said arms and each extending therefrom link pivoted at its opposite ends to the inner substantially transversely of the vehicle frame and each pivotally connected at its outerend to toward the other arm, a device on the inner end 30 ends of said ?rst mentioned links, said inter of one of said'links slidably engaging one of said guides, a connector pivotally connected to the inner ends of said links, and-a device on said connector spaced from its connection with the other link slidably engaging the other guide, the ?rst mentioned guide extending transversely of said frame and the last mentioned guide having lateral portions disposed at different angles to mediate link being provided with an arm form ing an extension of one of said first mentioned links, and means-for guiding the outer end of said arm laterally during thrust or pull on said ?rst mentioned links through said intermediate ele ment to e?ect relative movement between said ?rst mentioned links, one of said links faster or slower than the other link dependent’ upon the direction in which said swingable wheels are said ?rst mentioned guide, and means connected to one of said dirigible wheels for swinging said 40 operated, whereby said swingable wheels in any wheels in either direction. steering position are in different angular rela tion. ,. 8. A vehicle comprising a frame, a pair of sup porting wheels adjacent each end of said frame, 11. In a vehicle, the combination with a frame the wheels of one pair being dirigibly mounted and front and rear supporting wheels for said on said frame in spaced relation, means con frame,'the wheels at one end of said frame being nected to one of said dirigible wheels for operat mounted thereon to swing on substantially verti ing it in either direction, and connections be cal axes to effect steering of the'vehicle, means tween said dirigible wheels and said frame op operatively connected to one of said swingable erable to swing them together in either direction wheels for swinging it from normal position in and simultaneously control the movement of one 50 either direction, connections'between the swing wheel faster or slower than the other wheel de-, able wheel connected to said swinging means _ pendent upon the direction of swinging move and the other swingable wheel for swinging the ' ment of said dirigible wheels, said connections other wheel from normal position~ in either direc consisting of a pair of relatively movable links tion, whereby both swingable wheels swing in‘ pivotally connected at their outer‘ ends to said 55 the same direction when operated for steering dirigible wheels, an element between and piv the vehicle on curvilinear lines of travel, said otally connected to the inner ends of said links connections consisting of a pair of links disposed and means carried by said frame for guiding substantially! transversely of said frame and said element during movement of said links to / each pivotally connected at its outer end to one control the relative movement thereof. 00 of said swingable wheels and an intermediate 9. In a vehicle comprising a frame, a pair of link pivotally connected to the inner ends of supporting wheels adjacent one end of said said ?rst mentioned links and arranged to trans frame, a pair of dirigible supporting wheels ad mit thrust or pull from one of said ?rst men jacent the opposite ends of said frame, connec-, tioned links to the other ?rst mentioned link, tions between said dirigible wheels and said 65 whereby both wheels swing in either direction frame operable to swing said wheels together in either direction and simultaneously control the movement of one wheel faster or slower than _ when said swinging means are operated, said intermediate link being operable during swing ing of said swingable wheels to permit relative the other wheel dependent upon the direction movement between said ?rst mentioned links, of swinging movement thereof, the connections 70 and means for controlling the movement of said between said dirigible wheels consisting of a plate mounted on said frame and provided with guides, a link pivotally connected at its outer. end to each of said wheels, a device on the inner end of one of said links slidably engaging one of 7 I intermediate link to effect slower or faster move ment of one of said ?rst mentioned links rela tive to the other ?rst mentioned link, dependent upon the direction of swinging movement of said swingable wheels at either’side of their normal 2,411,570. - 11 12 position, whereby said wheels in any steering position are disposed in di?erent angular rela; positions, said last mentioned connections con tion relative to their normal position. 12. In a vehicle comprising a frame, dirigible on a substantially vertical axis torespectively connected at their outer ends‘ to said spaced wheels and a link pivotally connected to the inner ends of said transversely arranged links and operable to permit said transversely ar ranged links to move endwise relative to each different angular positions, connections between 4 other, and operating means connected'to said sisting of transversely arranged links plvotally supporting wheels disposed adjacent the opposite ends thereof, each wheel being mounted to swing first mentioned connections arranged to swing at the opposite end thereof for simultaneously 10 said wheels to angular positions and to simul taneously swing all of the wheels to their re swinging them in opposite directions, the wheels a wheel at one end of said frame and a wheel at one end of said frame being spaced, connec spective angular positions. tions between said spaced wheels adapted to swing them in the same direction into steering , ‘ PAUL E. HAWmNS. Certi?cate of Correction November 26, 1946. Patent No. $411,570. PAUL E.‘ HAWKINS ' It is hereby certi?ed that error appears in the printed speci?cation of the above numbered atent re uiring correction as follows: Colunm 9, line 26, claim -7, before the word ‘gii?erentigl” insert said; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case 1n the Patent Oi?ce. Signed and sealed this 25th day of February, A. D. 1947. [w] ' LESLIE FRAZER, First Assistant Gommissioner of Patents.