US2429172A - Steerable baby carriage - Google Patents

Description

Oct. 14, 1947.

R. l. sARAslN STEERABLE BABY CARRIAGE Filed NOV. 6, 1945 2 Sheets-Sheet;

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Patented Oct. 14, 1947 STEERABLE BABY CARRIAGE Raymond J. Sarasin, Fitchburg, Mass., assgnor to F. A. Whitney Carriage Company, Leominster, Mass., a corporation of Massachusetts Application November 6, 1945, serial No. 626,928

(ol. .28o-48) 6 Claims. 1

This invention relates to steerable baby carriages and the object is to provide an improved construction having means normally tending to return the parts to the centralized position for straight-ahead running, which means will be efficient and sensitive and present no undue impediment to intentional steering movements.

My invention will be well understood by reference to the following description taken in connection with the accompanying drawings, wherein:

Fig. 1 is a bottom plan View of the carriage;

Fig. 2 is a partial bottom plan showing the parts in a position assumed when a turn is being made;

Fig. 3 is an enlargement of a portion of Fig. 2; and

Fig. 4 is a section on the line 4 4 of Fig. 3.

Referring to the drawings, the carriage there shown comprises a body i supported substantially centrally thereof and at either side from the end portions of a cross-member I2 to which are joined by vertical pivots lli two non-parallel longitudinal reaches I6, the ends of which are connected by vertical pivots I8 to front and rear nonrotatable wheeled axles 2U. Herein the reaches incline inwardly from rear to front forming with the intervening segments of the axles an isosceles trapezoid when the parts are centralized and the carriage is pointed straight ahead. These parts form a deformable linkage and if, `for example, a lateral force is applied toward the right on the cross-member I2, the axles will be turned in a direction to make a turn to the left (Fig. 2) steering being eiected primarily by turning movement of the front axle although herein the rear axle also moves in a In the preceding sentence I have used, and hereinafter I shall use, left and "right with reference to the gures of the drawings, and since these are bottom plans the directions referred to are opposite to those which a person trundling the baby carriage would call left and right.

Describing further details of the carriage illustrated, the cross-member l2 is herein shown as supporting at .its ends the longitudinal springs 3ft by which the body proper is suspended. The cross-member swings between U-shaped members 48 (Fig. 4) attached tothe reaches it and which limit the angular movements of the latter. The pivot bolts,A lei have an extended bearing these members 48 and in the central portions of inwardly facing arcuate elements 33, the outer ends of which are rigidly secured to. the Sp11gs 34. i

The construction as so far described is not novel to the present application but is here disclosed as an illustrative` and indeed a preferred construction of steerable carriage.

It has hitherto been proposed to provide in a steering carriage oppositely acting springs such as ordinary helical coil tension springs for maintaining the same normally in position for straight-ahead running. I have found that if such springs are to be eiective on small displacements of vthe gear, they must be applied under considerable initial tension. Consequently the mechanism will be retained with considerable force in the centralized position, adversely affecting the ease with which steering could be effected. In the arrangement which I am about to describe oppositely acting spring devices are provided which, while conveniently and desirab-ly under initial stress, exert no or substantially no force on the steering mechanism in the normal position. One such device is additionally stressed as a turn is made in the appropriate direction, but the other is idle, the adjacent parts moving freely away therefrom.

, Such devices are conveniently embodied in entirely `separate and independent spring units as herein shown, wherein I illustrate right and left torsion springs 52 having central coils encircling the pivots le and arms 53 and 55 having hooked ends which engage respectively the crossmember l2 and the adjacent reach I6 at the forward side of the cross--member- These locations for the springs of the pair are exemplary of locations adjacent to partsr the angular relation of which varies in opposite sense in the steering movement-. Thus in moving from the position of Fig. 1 to the position of Fig. 2, the angle between the cross-member I2 and the lefthand reach diminishes while that between the cross-bar and the right-hand reach increases.

The springs may be positioned by a trapezoidal plate 57 held by the pivot i4 and having (see Fig. 4) downturned flanges 59 opposing the arms 53 and 55. The spring is maintained under initial compressive stress but its resilient expansive action is limited by the anges, and the arrangement is such that in the normal position oi the parts as illustrated in Fig. 1 the ends of I `the arms will just about touch the cross-bar l2 !15 though the spring is under initial stress between the flanges 59 of plate 51, it is not operative to exert any iniiuence on the steering action. Atthe left-hand side of Fig. 2, however, the legs of the spring are further pressed together in the diminishing angle between the cross-bar I2 and 5 the left-hand reach I6 and immediately but sensitively this spring exerts a force tending to restore the. partsto the/position otliig; l.' Ii the turn is tothe oppositeY direction, the left-hand spring will be idle while the right-hand spring 10 will be further compressed.

A carriage constructed as described .rolls for-- Ward smoothly without yawlng, but can be easily steered when desired.

I am aware that the invention may-:be enr'- 15..v

bodied in other specc formswithoutdepart ing from the spirit or essential vattributesthere of, and I therefore desire the present embodiment to be considered in all respects as illustrative:and'` not restrictive, as is in, fact clear in several mattersfrom the description -itselii Reference is to b e had to the appendedclaimsto indicate those principles ofthe invention exemplified by the particular embodiment' described and e which I desire to secure byfLetters-Patent;

I claim:

1, A steer-able baby carriagehavingf a bodysupporting under-frame andV agfpair of non-rotatable wheeledaxles incorporated in a-linkage deformableto; enforce a horizontal swinging movement of at least oneoi; the axles oniap.- plication of a transverse force toene-of said'vincorporated Aelements -andapair ofispring; devices associated Vwith the linkagewhich; in the; normal straight-ahead position .oithef parts,- exert sub;- stantially Y no force on; the-linkage and zare constructed and arranged to be stressedrespec.- tively as the turns are madeirr oppositedirections while there islost motion between the companion spring device andthe-parts of the linkage adf 4o jacent thereto.

2.A baby carriage comprising a body supported. substantially centrally and at either side thereof by vertical pivotsonapair vof longitudinal reaches which extend in non-parallel `relai tion and are pivoted byv vertical 'pivots atl their ends to irontand rear non-rotatable Wheeled axles.V the. pivotal 'points being arranged to cause turning movement vof at least onefof the. axles when al lateral pressure isexerted on the body, and a pair of 'spring devices normally substantially unstressed bywanyv` of@ saidparts, one lo.- catedi to be stressed-by the relative-angular movemen-t of'adaacent parts-asa turn is made inv one direction while the correspondingparts Aadjacent `5,5 the other have lost motion relative to said other and conversely when the turn is lmade in the other direction.

3.? A- baby carriage comprising albody supported from iront and rear axles, means for angularly moving one-of Ithe axles-:relativeto the.` body to steer the carriagefa pair ofi-springs positioned respectively adjacent parts the angular relation of-'which-varies in -oppositesense-in the steering movement; means placingthe springs under-stress and `delirr-iitingr the-resilient return thereof;'where byV said parts are substantially free from stress of @the springs when the axle-is'innormal position `0r-straigl'1t-ahead movement, said springs respectivel-y beingengaged y'andffurtlner stressed bysaid 7 0 y parts whenfthe turn is made-irreme- Qr: heothei directiom 4. A baby carriage comprising a body supported substantially centrally and at either side thereof by vertical pivots on a pair of longitudinal reaches which extend in non-parallel relation and are pivoted by vertical pivots at their ends to front and rear non-rotatable wheeled axles, the pivotal points being arranged to cause turningmovement ofl air-leastA oneffof the axleswhen a lateral pressureis'exertedon the body, av

pair of oppositely acting torsion springs having-l arms opposing parts which form angles at a pair;

of sad pivots, one of which angles increases as the other diminishes when the vehicle is steered, andrneans delimiting the movement of the arms impide-direction whereby the resilient stress of thespringsfls atA least substantially neutralized irrthestreight-ahead position of the parts.

5. A baby carriage comprising a body supported substantially centrally and at either side thereof by vertical pivots om. a pair of longitudinal reaches-- which; extend in nonfparallel. relation arxdzare pivoted-.by-vertical pivots at `'their ends to 1 front; and rear non-rotatable;wheeledf axles, the pivotalk points being arranged; to cause turning, movement; of :at: least: one :oizthef axles when a lateral pressureis, exerted on the body, apair of oppositelyacting;torsion-"springs havingarms opposingparts-whiclfrzform angles at: arpairV of saidrpivots;- one ci which' anglesincreasesv as the othelsfdimirrishes when thefvehicle is steered., and means-delimiting theffmavement-of the yarms in one :direction,',vtherelcy1 the resilient stress .of Ythe springs isat least substantiallyneutralized in .the straight-ahead position of the parts, said 'means comprisinga; plate secu-red bythe-,pivot Aand'having flanges opposing the arms.

k6. Abaloycarriage for trundlingfby hand; comprisi-ngr-a; body; .aq frame.- suspending 1 the body, a pair-f of non-,rotatable :wheeled axles.v adiacent the ends ofthebody, and meansor connecting the frame Yto the. axles for:v supporting .the body sub.- stantiallycentered thereon,Y said .means consisting oilinksvmountedonsaid frame atboth sides of the center line of thefbodyand pivoted-Lto. said frame andxaxles onnpairs vof'transversely aligned vertical' axes,. the. linksbeing"V proportioned and arrangedto enforcefa horizontal swinging movement 'ofiat least'. one, of the axlesfon application otra- .transverseforce to onevol said pairs as.- by

Vaglatera'l pressure on the-frame, a pair-of springs positioned :respectively adiacenti` certain offthe above-recitedparts-thefangular relation of which varies` in oppositel sense in. thew steering movement, meansplacing thesprings under stress and .delimitingf the. resilient vreturn thereof, whereby said parts; are;substantially-J free: fromstress of the. springs whenthe axle is in normal position for straight-ahead movement, .said springs respectively being engaged and further stressed by said zparts when; tlieturn-visv madeA in one orthe other direction` RAYMOND iJ', SARASIN.

REFERENCES CITEDl` The following referencesv are of 'record in the lle -of' thispatent:

UNITED- STATES. PATENTS Number Name 1 Date l 1,100,713 1 Colson June-23, 1914 1,564,662 Flemlster Dec. 8, 1925 2,398,650.` Lachance Apr. 16,1946

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