US2233478A - Reversible seat base - Google Patents

Description

March 4, 1941. o. E. HILL 2,233,478

REVERSIBLE lSEAT BASE Filed Oct. 27, 1938 2 Sheets-Sheet 1 www. MQWMTM March 4, 1941. o. E. HILL 2,233,478

REVERSIBLE SEAT BASE Filed Oct. 27, 1938 2 Sheets-Sheet 2 ff' Lg f@ Z @gam/M UQMW'WW.

Patented Mar. 4, 1941 UNITED srfl1-2`s PATENT OFFICE REVERSIBLE SEAT BASE Oiva E. Hill, Gardner, Mass., assigner to Heywood-Wakefield Company, Gardner, Mass., a corporation of Massachusetts `Application ctober 27, 1938, SerialNoyZ-EZZSS s claims. (01455-96) f vThis invention relates to reversible car-seat bases of the cam-controlled type which rotate from one position of use to the other about a vertical axis and which are automatically shifted 5. away from the adjacent wallof the car or other vehicle in which they are mounted during -the initiall portion of their reversing movement from either position of use. The purpose of such shifting movement toward the aisle is to enable the l0 seats to be located very close to the wall of the vehicle and yet tov be reversed without interference between the cornersof the seat and the wall, thus providing maximum vaisle space when the seats are in use.

1.5 The reversing mechanism hereinafter described is a modification of or improvement over the mechanism described in my application Serial No. 200,825, filed April 8, 1938. The mechanism therein described gives to the seat not only an endwise motion away from the wall` but also a considerable iront-and-rear motion as well. Accordingr to the present invention, this front-and# rear movement is materially reduced with relatively little reduction in the movement of the seat away from the wall.

Another object of the present invention is a Vsmoother reversing movement than that of the earlier mechanism. 'I'he present invention `'also includes improved means for holding'th'e seat releasably not "only in its normal positions of use but also in a half-way position in which Athe seat may face the wall or the aisle, depending upon the manner in which the seat is mounted 'onits carrier. i rFor al morecomplete understanding of the invention, reference may be had to the following description thereof, and to the s drawings of Figure 1 is an end elevation of ra car seat or chair. l

Figure 2 is a fragmentary oor plan View of a vehicle showing the arrangement of seats or chairs embodying the invention.

Figure 3 is a section on the line 3-3 of Figure 2, ona larger scale. f

Figure 4 is a section on the line 4+!! of Figure 3. Figure 5 is a section on the line 5-5 of yFigure 3. Figure 6 is a section on the line 6--6` of Figure 3, on a smaller scale. Figure'l is a view similar to FigureV 6 showing additional elements.

Figure 8 is a View similar to Figure 7, showing the parts in a dilferentposition of operation.

Figure 9.is av section on the line 9-,r9fof Figure 5&5 8, o n `a largerscale. 4 f

Figure 10 is a geometric diagram to illustrate the operation of the cams.

The chair shown in Figure 1 includes a base ,or pedestal .l0 which is secured to the floor of the vehicle.r On this base is supported a seat l2 which 5 is provided with a back I4 and `one vor morezarmv rests |61. .As indicated in Figure 2, the seat may be a double seat lconsisting of two individual units separated by an arm rest. The invention, however, maybe embodied fin other varieties of sin- 10 gle or doublereversible seats. Figure 3 illustrates a reversinf.5..seat support or base on which a seat' of any desired kindmaybe mounted. This base is in theform of a pedestal 20 having a'ilatdsop plate 22 on rwhich the seat is slidable. .Instead 1 5 ofthe pedestal any other preferred form of base or support may be employed havinga horizontal surfaceon which the seat is slidable. In order to guide the reversingmovement :oia seat so that the armrests and backs of theseats Will `clear the 20 wall of the vehicle when theseat is turned, guiding mechanism such aszis' illustrated in Figures ,3 and 6 is provided.: As shown, thisr guiding mechanism comprisesa pair of cam Afollowers 24 .and 26 which may conveniently bein the form of roll- 25 ersrotatable onk vertical stems 28 and 30 respecA tively. Thesestems project upward from a spacer bar 32 located beneath the plate 22, and, inthe assembledchair, are secured to the'frame yof the seat :42. The bar 32 cooperates with the `seat 30 frame to maintainthe cam followers or rollers 24 and126 at a constant distanceapart'.

.As indicated in Figure6,.the rollers 24 and 26 bear against and are guided by cam-edges which denne A'anaperture 34 inthe plate 22. These cam 35 edges are in the formlof a closed curve which is symmetricalA with respect to the longitudinal median of the base. lImmediately belowthe rollers -24 and 26 are discs 350i larger diameter, these discs having portions projecting under the 40 margins ofthe lplate 22 along thecam edges so as'to act -as hold-down members for the 4seat ll2. Thecamedges consist of a pair of arcuate portions y36 and :38 which lare of equal length and curvature and areA tangent respectively to the 45 rollers `24 and 26 when .thelatterare lin their normal zpositions, the center of curvature ofthe arc being in the axis of the stem l30, thatlis, the :centertoi `the roller 26, the center of curvature :of the arc `38 being on the axis of the stem 5,0 28, that is,th e center ofthe roller 24. The corresponding opposed ends of these two arcuate .portions `of ,the cam `edge are connected together fby two arcuate edge portions 46 .and-,hof'unegual length and curvature.l The latter arcs are struck 355. invention,.

from a common point on the longitudinal median of the base, the position of this point being determined by the length of the arcuate edge porfit when in normal position. The arcs 46-and 42 are both bisected by and symmetrical with respect to the longitudinal median of the base.

Both of these arcs have a greater curvature than' the arcs 36 and 38.

Referring to Figure 10 for an explanation of the geometrical relation between the various portions of the cam in comparison with the cam described in my said application Serial No. 200,825, A and B represent the centers of the rollers 24 and 26 when the seat isin one of its normal positions of use. The cam portion BC is struck with A as'a center and represents the 4path of initial movement of. the roller when the seat is -being reversed. Inlike manner, the cam portion AD is struck with B as the center and represents lthe iinal movement of the roller 26 .when theseat is reversed. If these arcs are continued to intersect at E, as indicated in light lines; the arcs CE and ED represent the path of movement the roller 26 would have from C toy D if the cam edge were shaped as described in my said application Serial No. 200,825. ,In such case, the roller 24 would follow an arc AFB vwhile the roller 26 paused at E, the arc AFB being struck with`E'as its center. Accordingto the present the .roller 26 is made to follow the arci'CJD in moving from C to D, and the roller 24 moves along a path indicated by the arc AHB. The line `ACrepresents. the position of the bar 32...when vthe roller 26 reaches the end of the arc BC.l The line BD represents the position of the bari 32 when the roller 26 is at'the end of the arc 1 AD. The intersection G of these twolines is thefcenter of curvature of the .arcs CJD and AHB.. It is vevident that, since every point of the arc AI-IBisequally distant from the center C1, and since every pointof the arc DJC is equally distant from. thecenter G, the rollers 24 and 26 follow. the arcs indicated in ydark lines in Figure l during a reversal of the seat. .Thus,.whi1e1the roller N24 remains stationary lat A, the roller 26 moves from B to C. .Theroller 24 then leaves the point A .and moves along the arc AHB as the rollerv moves along the arc CJD, the spacer bar 32 'rotating about the point G until it reaches the position indicated by the line BD. Thereupon'the roller 24 remains at B while the roller 26 moves from D to A to complete the reversing movement of the seat. When the seat is reversed in the opposite direction, these movements of the rollers take place in the reverse order. As a result of any reversing movement, the lcenters of the rollers 24 `and 26 exchange places. During the reversing movements, the seats will face either the wall or aisle of the vehicle according to the manner in which they are secured to the guiding mechanism. Thus, if a seat is secured tothe stems28 and 36 so .that it faces to the left when the rollers 24 and 26 are in the positions indicated in Figures 6 and '7, the seats will face the Wall during reversingmovements since the bar 32 swings in a clockwise direction from ythe position shown in those figures.` If, however, the seat is secured to the stems so that it'faces toward the right when therollers 24` and 26are in the positi-ons shownin Figures 6 and?,

then the seat will face the aisle during the reversing movements.

The diagram in the central portion of Figure 10 indicates the path of movement of the center point of the spacer bar 32, which is preferably directly-below the center point of theseat I2. Thek ipoint K is the position of the -center of the spacer bar 32 when the seat is in either of its normal positions of use. As the barswings about A as a pivot, its center moves to the center moves along from M to K. Ihn installing a seatbase of this type in a vehicle, the base is arranged so that the point H is toward the wall Yof the vehicle,A the point E being toward the aisle. Thus the broken line KN represents the displacement of the center of the seat away from the wall of the vehicle during the initial portion of the reversing movement. The line NLlikewise representsthe displacement of the center of the seat in a front-an'd-rear direction during such initial portion of the reversing movement. Forv purposes of comparison, the arni'KLv is extended to P to' represent the movementaof theseat center'when a three-cornered campedge, suchV as is described inv said applica` tion g Serial No. 200,825, is employed, theremainder of the movement of'thecenter being along the arcs `PR. and RK to complete` the reversing movement of the-seat. The broken line PR indicates the front-and-rear displacement ofthe seat `center from the-median line KS during the reversing movement. `It is evidentfrom this figure thatl the use of acam made according to the present invention results yin' a marked, reduction in the Afront-and-rear displacement of the seat center Witha considerably smaller reduction of displacement --away from Athe -wall of the vehicle. This result" is highly desirable-since the quick-movement away from the vrwall is retainedv without being accompanied by excessive front-and-rear' movement whichwould tend to cause interference between point L. During the rotation of the spacer bar about the point G, its center moves along. i the arc from L to M. During the final movement ofthe spacer bar about B as a pivot, its

the corners ofthe seat and the front or rear 'por- 'Y tions of adjacent seats in the vehicle.

Toassistthecan ledges to function properly in guidingthe cam-followers as'desc'ribediand tov minimize side-lash of the seat carriage during reversing movement thereof, auxiliary means are provided for shifting the :axis of rotation of the' seat carriage to `a point between the followers;

which-point serves as a pivot for the carriage during` the mid-portion of its reversing "move--l mentV in either direction. To thisV end 4the spacer bar 32 may be provided` with Ia'lugr 56 which iis adapted,v to engage in a notch 52 formedQin-'a cross bar 54'secured to the base las indicatedfin Figure 9. The lug. 50 preferably projects 'down below the spacer bar so Aas not Ito' interfere with the movement of the Vcam followers 24 and-.26. The notch 52 is Ylocated von 4thelongitudi'na'.lfm'edian of the base at a point corresponding. tdt-he point Gef Figure 1-0.l lwhenl-.heiuigfsup reaches the notch 52 in the,` course of 'a reversing movementl of vtheseat carriage, the axisv of rotationof the carriage thereupon shifts vaway from the-cam follower \24 and the'lug 50 serves asa temporary pivot during the portion of thereversingnfiove`v ment in which the spacer bar' moves from 5a position indicated by the line "AC in Figure "10'fto la posit-lon* indicated by 'the line flan. Ae' me:

ment the follower 24 reaches thtle'cornfof '(9 60 and 62,. which, as indicated in Figure 3, mayy -be secured (as by welding or riveting) estal itself. Each of these socket to the pedmembers is provided with. a concave arcuate recess `or socketA 64`in1which, as indicated in Figure 5, is a projectin'g .lug or stop '85. Cooperating withthe recesses 64 `are a pair of end members 10 andl 12 which are mounted at the ends of the tubular spacer bar 32 and which have fan-.sh-apedend portions 14 with a curvature to fit in the recesses 64 when Ithe seat' is in either of its normal posi-tions of use. As. shown in Figure 5, the fan-shaped portions 14"engage the recesses 64 at a level just above the lugs 66; Below the Icenter of the fan-shaped portion 14 of the member 10 is a downwardly projecting lug16 which is on the s-ame level with the lug 66 so that it is stopped by the lug S6 when the spacer bar is in the position shown in Figure 4. The end member 16 may be permanently secured by welding or `otherwise to the spacer bar y32, as indicated in Figure 4, or may be yieldingly mounted as indicated in Figure ber 12 is yieldingly mounted at the other end of the spacer bar. The fan-shaped portion 14 of this end member is adapted to slide in a pair of longitudinal slots 16 extending from the end of the spacer bar, and the sliding movement of the member 12 may be limited by -a pin 80 which slides in a slot 82 in the bar. Within the bar a compressed spring 84 presses the memer 12 outward, the inner end of the spring `84 bearing against a transverse pin 86. 'The spring 84 presses the convex end of the end member 12 into the recess 64 to hold the seat yieldingly in a position for use. When it is desired to reverse the seat, the arm or back yof the seat may be given a quick pull to cause the member 12 to ride out of the recess 64. The seat is then reversed on the pedestal, its movement being guided -by the cam followers 24 and 26 engaging Ithe cam edges as hereinbefore described. This movement results in the end member 10 entering the recess llill which has just been vacated by the end member 12, the lug 1B engaging the stationary lug 66 .to prevent movement of the end member 14 :beyond the recess. As the seat reach-es its reversed position, the spring 84 yields to permitl the member 12 to ride into ythe recess 64 which has been vacated by the member 10. Thus the seat is held rele-asably in reversed position.

If it is desired to retain the seat in an intermediate position of use wherein the seat faces either the wall of the vehicle or the aisle, the stationary socket member 90 is mounted on the pedestal so as to be engaged by the end member 10 when the seat is in its mid position between the normal positions of use. In order to retain the seat in its mld position, -it is preferable to employ the fixed transverse member 54 with its notch 52 in which the lug 50 engages when the seat is in its mid position. Since the lug 50 is unyielding, the end member 10, instead of being xed within an end of the spacer bar, is sildably positioned therein and is `outwardly pressed by a spring 92 bearing against .a pin 94, as shown in Figure 9, the movement of the end member being limited by a pin 96 which slides in a slot 98. 'Ihe end member 10 is thus mounted in the same man- 9. The end memto the latter except for-the lugs 16.

It is evident that` lvarious'. modifications and changes may be,` made in the embodiment of the invention hereinv shownandv described without.

departing from the spirit or scope: thereofl as defined in the following. claims.

Iclaim:

1. In a reversibleseat base mechanism", aahorizontal stationary plate on whicha seat` is slidable,` said plate having. an. aperture dening a cam edge in` the formv off av closed curve consisting of four circular arcs,.two of said arcsbeing of equal length. and curvature and. alternating,

with the other two which are of different curva.- ture but are struck from a common center, and a guide member for said seat includingv a: pair of cam followers engaging' said camv edges at opposite sides of said aperture, and spacing meansfor said cam followers;

2. A reversing car-seat basecomprising a stationary pedestal with a horizontalI top, a seat carriage slidably supported on saidV horizontal top, said top having an, aperture therein dening cam edges, a pair of cam followers spaced a xed distance apart and attached to said seat carriage, said aperture having a pair of corners occupied by said followers when the carriage is in either of its positions for use and a pair of arcuate edge portions adjacent to respective corners whereby one of said followers acts in its corner as a pivot for the carriage during the initial portion of a reversing movement o-f the carriage and acts in the other corner as a pivot for the carriage during the final portion of said reversing movement, and means operative during the intermediate portion of the reversing movement to shift the axis of rotation of the carriage to a point between the two said followers and to shift said one of said followers from its corner to said other corner.

3. In a reversible seat base mechanism, a horizontal stationary plate having an aperture therein defining a cam edge in the form of a closed curve consisting of a pair of arcs of different curvature struck from a common center on the longitudinal median line of the base and bisected by said line, and another pair of arcs of equal length and curvature connecting respective ends of the rst said arcs, a pair of cam followers simultaneously engaging opposite portions of said curve, and means for maintaining said cam followers constantly spaced apart, said spacing means being attachable to a seat on said plate whereby said cam followers and spacing means move with the seat and guide the movement thereof.

4. In a reversible seat base mechanism, a stationary member having an inner cam edge in the form of a closed Icurve symmetrical with respect to the longitudinal median of the base, said cam edge having two arcuate portions of equal length and curvature on opposite sides of said median and two arcuate portions of different length and curvature struck from a common center on said median and joining the ends of said equal portions, a pair of cam followers engaging said cam edge, means including a spacer bar for maintaining said cam followers at constant distance apart, means releasably holding said cam followers at the junctures of the longer of the unequal arcs with the equal arcs, a lug on said spacer bar between the ends thereof and movable therewith, said lug being located so that its path of movement crosses said median at ner as thev end member12 and; may bet similar-- on which said cam .followers are said common center, ,andy a stationary member having a recess arranged to receive said lug when it reaches said common center. t

5. In a reversible seat base mechanism on` a stationary base, a seat-guiding member comprising a. pair of cam followersand a spacing bar mounted, said cam followers having mutually exchangeable normal positions of rest to the front and rear of the longitudinal median of the base when the seat is in either of its normal positions for use, a lug mounted on saidspacing bar between said cam followers, and cam means cooperating with said cam followers and lug to guide the reversing movements of the seat, said cam means comprising a pair of converging arcuate edge cams each tangent at one end to one of said cam followers in normal position and having its center of curvature at the center of the other cam follower, a stationary member having a notch` at said median line engageable by said lug during a vportion of the reversing movement of the seat whereby said lug serves as a temporary pivot for the seat, said cam means also including a third arcuate cam edge extending from one normal position of the cam followers to the other and having its center and having its center of curvature in said notch for the lug.

6. In a reversible seat base having a horizontal plate with an aperture therein dening an edge cam, a. pair of cam followers engaging said cam at opposite points thereof, and spacing means for maintaining said cam followers at a constant distance from each other, means for releasably holding said cam followers in predetermined positions relative to said cam, said means comprising a pair of abutment elements with arcuate recesses mounted o-n said base, and a pair of end elements projecting from the ends of said spacing means and having convex extremities fitting said arcuate recesses, one of said end elements being yieldable lengthwise of said spacing means for snap action in engaging with and disengaging from either Vof said recessed abutmentelements.

OIVA E. HILL.

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