US2240620A

US2240620A - Car-seat base

Info

Publication number: US2240620A
Application number: US285711A
Authority: US
Inventors: Oiva E Hill
Original assignee: Heywood Wakefield Co
Current assignee: Heywood Wakefield Co
Priority date: 1939-07-21
Filing date: 1939-07-21
Publication date: 1941-05-06
Anticipated expiration: 1958-05-06

Description

y 1941. I o. E. HILL 2,240,620

CAR-SEAT BASE Filed July 21, 1939 5 Sheets-Sheet 1 jzww j w w M I y,

y 1941- I o. E. HILL I 2,240,620

CAR-SEAT BASE Filed July 21, 1939 3 Sheets-Sheet 2 May 6., 1941. o, E. HILL 2,240,620

CAR-SEAT BASE Filed July 31, 1939 v s Sheets-Sheet s //i, ./W m

Patented May 6, 1941 UNITED STATES PATENT OFFICE CAR-SEAT BASE iva.E..Hill, Gardner, Mass., assignor to Heywood- Wakefield Company, Gardner, Mass, at corporation of Massachusetts Application-EH21, 1939, :Serial No. 285,211

Claims. (01.,155-96) This application relates to improvements in car-seat bases of the type which are reversed from one position to the other by rotation accompanied by a shifting movement away from the wall of the vehicle during the initial portion of the rotative movement, and back toward the wall during the final portion of the rotative movement. The invention relates more particularly to a seat base of this kind having its reversing movements controlled by cams cooperating with a pair of cam followers mounted on the movable seat carriage and arranged in the frontto-rear median plane of the carriage so as to exchange places with respect to the stationary pedestal when the seat is reversed from one position to the other, as, for example, the seat bases described and illustrated in my copending applications Serial No. 260,825, filed Aprii 8 1938, which matured into Patent No. 2,215,817 on September 24, 1-940, and Serial No. 237,233, filed October 27, 1-938.

It is an object of the present invention to provide a rotating oar-seat base of the foregoing type which is simple and inexpensive in structure, which is rugged, and which operates smoothly during the entire movement of theseat from one position .to the other. Cam-controlled reversing mechanisms of the kind described m said applications are characterized by the use of one of the pair of cam followers as a pivot for the initial and final portions of the reversing movement so as 'to swing the seat away from the wall to clear the wall in turning, and then to swing the seat back close to the wall at the end oI .rthe reversing movement. Between these portions of the reversing movement, the pivot shifts and the seat rotates about one or more other pivots. vAccording to the present invention, auxiliary .cams and followers are provided, {these being so constructed and arranged that the shifts in pivot axes, instead of being abrupt, are progressive or continuous away from the initial axis ,then back to the final axis. According ItO this invention, also, the path described by the center point of the seat carriage is free from abrupt changes in direction. Furthermore,- side-lash at critical parts of the reversing movement is reduced, and the stresses on the various portions of the :cam edges are more evenly distributed, so that the mechanism has a greatly increased life.

Various other advantageous features are to :be.

Figure 1 is an end elevation of a :car seat having a base embodying the invention.

Figure 215 a plan view of the same showing portions of adjacent seats and the vehicle wall.

Figure 3 is a section on the line 3-3 of Figure 2.

Figure 4 is a section on the line 4-4 of Figure 3.

Figure 5 is a perspective view of a socket member employed in the seat base.

Figure '6 is a section on the line 6-6 of Figure 3.

Figure 7 is a section on the line 1-1 of Figure 6. 7

Figure 8 is a diagrammatic plan view of a cam system equivalent to that shown in Figure 6.

Figures '9, 10, 1'1 and 12 are diagrammatic plan views of modified forms of cam systems.

The invention may be embodied in various forms of seats or chairs but is shown as embodied in a car seat such as is often employed in railway cars where it is desirable to reverse the position of the seats in accordance with the direction in which the car is to be operated.

Figure 1 shows a chair including a seat cushion 20, arm rests 22, a back 24, and a base genorally indicated at 26. The base may be of the central pedestal type or may be supported at its ends. The former is indicated on the drawing. As shown in Figure 2, it is desirable to mount the seats as close to the adjacent vehicle wall 30 as possible so that maximum aisle width can be had. Since it is necessary that the corners of the seat clear the wall when the seat is being rotated to reverse its position, the seat base is constructed with mechanism by which the seat moves away from the wall during :the initial portion of its reversing movement and back toward the wall during the final portion of such movement. To this end, the base '26 is constructed with a stationary pedestal 32 having a horizontal top 34 in which is an opening 36 defining internal edges of the pedestal top which serve as cam surfaces. Coopcrating with these cam surfaces are a pair of

cam followers

48 and 42 which, as shown, may be in the form of suitable rollers rotatably mounted on vertical studs &4 and t6 which are secured to a transverse bar 48 and project upwardly therefrom. The

studs

44 and 46 project through a portion of the seat carriage 50 on which the seat 20 with its arms rests 22 and back 24 is directly mounted. The upper portions of the studs 44 and 4B are preferably threaded as indicated in Figurea :to receive nuts 52 and 54 to secure the carriage to the "bar '48.

thereof. A reduced portion 66 of the plunger.

64 projects through a hole in the web 58, a pin 68 being thrust through the reduced portion 66 to limit the outward movement of the end piece 62. A compression spring it bears against the Web v 58 at one end and against a shoulder 12 on the plunger 64 at the other end so as to press the end piece 62 as far outward as the pin 68 will permit. As is evident from Figure 4, the end piece 62 can be pressed inwardly against the spring it. The

end pieces

60 and 62 are adapted to fit in curved recesses l4 in socket membersflfi which are preferably forgings welded or otherwise secured to the pedestal 32. The curved edges of the

end pieces

50 and 62 are preferably concentric respectively with the axes of the studs 44 and 65 for the reasons hereinafter ex:- plained. Below the fan-shaped portion of. the end piece 68 is a vertical web '58 which is adapted toengage a stop element 80 formedon the socket member 18. Immediately above the fanshaped elements. 63 and 62 are hold-down elements 8| which project under the portions of the top 34 adjacent to the aperture 35 to maintain the seat carriage upright on the top of the pedestal.

As indicated may be in the form of a suitablelug withinthe curved recess E4, the lug 80 being preferably midway between the upper' and lower edges of the socket member it so that the member can be used on either the front or rear wall of the pedestal, thus eliminating the necessity ofmakins gh a e ts, V

- As shown in Figure 6, the opening 36 is roughly triangular in shape, the corners of the triangle being sockets adapted to receive the cam"followers t and 42. A side 82 of the triangle is substantially straight and is parallel to the ends t mes ah the 'sqe e tthe en il t i side being likewise in a line parallel to the ends of the pedestal. The cam followers 4 0;and 42 are normally seated in the sockets at the end 9f the straight edge 82 and are disposed inthe median longitudinal or front-to-rear plane of theseat carriage, During the initial portion of a reversin'g movement, the cam follower 4B is kept,in'itssocket or corner of the opening 36 by engagement of the web 18 with the stop lug 80 and by engagement of the follower 42 with an arcuate edge portion 84 of the opening 36 which is concentric with the oppositeso cket, and serves as atemporary pivot, for the initial rotative' movement" of the seat. During such initial movement, the cam follower 42 moves alon the arcuate edge portion 84 of 'the cam until it reaches a point 86. At this point the curve of the "cam edge is reversed so that the follow eri42 no longer retains the follower 40 in its corner. When the follower 42. reaches the point 86, however, an auxiliary cam follower 98, which, as shown, is located on the bar48 midway between the followers 49 and 42 and which projects downwardly from the bar, effectively engagesthe edge 92 0f a cam member 34 which is mountedbelow, the top plate 34. The cam edge 92 .istconc'ave at in FigureBQthe stop member 89- the point where it is engaged by the follower 90, the radius of curvature of this portion of the cam edge being considerably greater than that of the follower itself. Thus, when the follower 90 engages the edge 92, its progress is not abruptly stopped nor is its direction abruptly changed. The curved edge 92 guides the follower 9D in a more gradual change of direction. As the follower Qil starts its movement along the edge 92, the follower 40 moves away from its corner and along the cam edge 82. As seen in Figure 6, the initial movement of the follower 40 toward the right takes place while the follower 98 is still moving downward and toward the left. Since the

followers

48 and 90 are thus moving in opposite'directions at the same time, it is evident that at that moment the axis of rotation of the seat] carriage 'is between the two followers.

. Thus, by reason of the shape of the edge 92, the

axis of rotation of the seat is progressively or continuously shifted from the follower along the bar {8 to the follower 90. As the follower 90 travels along theedge 92 it soon changes itsdirectionso as to move towardthe right. Meanwhile; thefo lowe 2 s. moving s ow y wa d the left so that at this time the axis of rotation ofthe; seat carriage is-moving between the follower; 90 and the follower 42. Thecam edge 84 endsin 'a corner or socket 9 4 which is shaped to receive the follower 42 when the carriage reaches the mid-point of its turn. At that instant, the follower 42 is the pivot point or fulcrum about which the seat carriageswings. Immediately thereafter th e follower 42 begins to move out of the socket 34 and to move toward the left. Since at this time the follower 90 is moving toward the rightalong a portion 96 of the auxiliary cam edge,itis evident that the pivot or axis of rotation of the seat carriage is shifting along'the bar 48 fromjth e follower 42 to the follower ill). Whenthe follower 90 reaches a point 98, it is for an instant the pivot of the seat carriage." During further movement of the carriage, the'axisoffrotation shifts along the bar 48 until ifr'eatchs the follower 48 when this follower reaches the right-hand corner of the opening 36 prev ouhy occupied'by the follower 42, where further progress is positively stopped by engagementoring web 18 with the stop lug'80 on the right-hand socket'member 76.7 At this point, the follower 42 .has'reached a point Hill on the cam edgeat which point the cam edge extends in an arc-uateicurve to the left-hand corner of the opening 36, this curvebeing concentric 'with' the When the follower '42 passes 'th'e'point 100, it thereupon becomesefiectiveto retain the follower 40 in the right-hand corner -while the follower 42 travels along the edge to the left-hand corner originally occupied'bythe follower 48. The movement of thefseatcarri'age'isthus characterized by the absence of'any abrupt shift in the axis ofrotation, and consequently by the absence of any abrupt change in the direction of movement .of the centerpoint of the seat carriage, as indicated in Figure 8; V

The path followed by the cam follower (and henceby'the carriage center) during a reversing movement of the seat is illustrated by a broken line in Figure-3 which shows diagrammatically a pedestal tophaving an opening 36 identical with that shown in Figure 6 and an auxiliary cam member having cam edges identical with those of the -cam member 94, these edges being extended to the limits of movement of the cam follower 90. 'A seat-base mechanism made asshown in Figure 8 would operate in identically the same manner as that shown in Figure 6, but, since the follower 9!} does not become effective until it reaches the point 92, the upper portion of the auxiliary cam plate may be omitted, as shown in Figure 6, to save weight. I

Figure 9 shows a modified form of the invention including a pedestal top I I having an opening II2 therein defined by a series of cam edges along which a pair of followers H4 and H6 move during a reversing movement of the seat carriage. These cam followers may be mounted on a bar IE8 which also carries a pair of auxiliary cam elements I20, E22. The auxiliary cam followers are preferably in a different plane from the cam followers I I4 and I It so as to engage the cam edges of an auxiliary cam member I24. During the rotation of the seat carriage, the cam follower H4 serves as the initial pivot or axis of rotation for the carriage and the cam follower H6 moves along an arcuate edge I26 which is concentric with the axis of the cam follower 4. As the bar H8 swings about the follower II4 as a pivot, together with the seat carriage of which it is a part, the auxiliary cam follower I reaches the cam edge of the plate I24 at the point I28. At this point, the cam follower I20 becomes effective, resulting in a progressive shift of the axis of rotation of the carriage along the bar H8 from the follower II4 to the follower I20. Soon afterwards, the auxiliary cam follower I22 engages the cam edge of the plate I24 at the point I36, whereupon the follower I22 becomes effective, resulting in a progressive shift of the axis of rotation along the bar H8 to the follower I22. The follower 22 thus becomes the momentary pivot when the seat carriage reaches the mid-point of its reversing movement. The axis of rotation then moves progressively in the opposite direction to the mollower I20 and eventually back to the follower II4 when the latter reaches the right-hand corner of the aperture IE2. The broken line with arrows shows the path followed by the center of the seat carriage a,

during a reversing movement.

Figure 10 shows a pedestal top I32 with an opening I34 therein defining cam edges along which a pair of cam followers I36 and I38 move during reversing movement of the seat carriage. The cam followers I36 and I38 are at opposite ends of a spacer bar I40 which is virtually a part of the seat carriage which rests on the top I32. Below the top I32 is an auxiliary cam plate I42 having cam edges engageable by an auxiliary cam follower. This cam follower actually comprises two followers I44 and M5. During the initial portion of a reversing movement of the seat carriage, the follower I36 remains in its corner while the follower I 38 moves along an arcuate edge portion of the opening I34 concentric with the axis of the follower I36. When the follower I38 reaches the end of this arcuate portion, the auxiliary follower I44 engages the cam edge of the plate I42 and becomes effective to shift the axis of rotation of the carriage progressively from the follower I35 to the follower I38. Soon afterwards the follower I46 becomes effective to shift the axis of rotation of the seat carriage to its own center, the follower I35 being the momentary pivot as the seat carriage is passing the mid-point of its reversing movement. The further action of the cam followers is to shift the axis of rotation of the seat carriage prolower I36 again becomes the pivot when it reaches theright-hand corner of the aperture gressively back along the bar I49 until the fol- 75 I34. The final portion of the rotating movement of the seat carriage takes place as the follower I38 moves along an arcuate edge portion of the aperture I34 until it reaches the left-hand corner originally occupied by the follower I35. The path of the carriage center is shown by the broken line.

Figure 11 shows another form of seat-reversing cam structure including a pedestal top I50 having an aperture I52 therein defining cam edges along which a pair of followers I54 and Iiitare adapted to move during the reverse movement of the seat carriage. These cam followers are at the ends of a bar I58 which also carries an auxiliary cam follower IEO. The latter is approximately in a semi-circular form and is adapted to rotate in a circular recess I52 in a cam plate I64 mounted below the top I50. During the reversing movement of the seat carriage, the follower I5 3 serves as a pivot while the follower I moves along an arcuate cam edge until the auxiliary cam follower I6!) enters the circular notch-I52. Thereupon the follower I becomes effective and serves as the pivot for the seat carriage until the follower I55 reaches the right-hand corner of the aperture I52, whereupon the follower I54 again serves as the pivot while the follower I55 moves up into the lefthand corner.

Figure 12 shows another form of cam mechanism including a pedestal top Ill] having an aperture I'IZ therein defining cam edges along which move a pair of triangular shoes I'M and I76. These shoes are each pivoted on the ends of a bar H8 to which the seat carriage may be secured. Below the top IIfl is an auxiliary plate I85 having cam edges engaged by an auxiliary cam follower I82 which is mounted on the bar I'I8. The aperture I22 is shaped with notches I84, I86, I88 and I90. As shown in Figure 12, the shoe I14 has one of its corners engaging in the notch I84 when the seat carriage is in one of its positions of use. During the initial portion of the reversing movement, the shoe I14 remains stationary while the shoe I slides along an arcuate cam edge. At the same time the auxiliary cam follower I 32 moves along the cam edge of the plate I until it reaches the point I92, whereupon the auxiliary cam follower I82 becomes the temporary pivot while the shoe I14 moves along the upper edge of the opening I'I2 until it enters the notch I90. The shoe I'I4 thereupon becomes a pivot for the final portion of the reversing movement of the seat carriage, during which movement the shoe I16 moves along another arcuate edge portion of the aperture II2 until one of its corners enters the notch I86.

It is evident that various modifications and changes may be made in the embodiments of the invention herein shown and described without departing from the spirit or scope thereof as defined in the following claims.

I claim:

1. A reversing car-seat base comprising a stationary pedestal having a pair of spaced sockets arranged in a line parallel to the ends of the pedestal, a seat carriage movable on said pedestal, a pair of cam followers on said carriage normally disposed in said sockets, an arcuate cam surface on said pedestal concentric with one of said sockets and engageable by one of said cam followers during the initial portion of a reversing movement of the seat carriage to hold the other cam' follower in its socket, cam means on said pedestal and carriage for causing said other follower to shift from its socket to the other socket during the intermediate portion of said reversing movement, and a second arcuate cam surface on said pedestal concentric with said other socket and engageable by said one follower during the final portion of said reversing movement to hold said other follower in said other socket.

, 2. A reversing car-seat base comprising a pedestal having a horizontal top with cam edges, a seat carriage movable on said top, a pair of cam followers carried by said carriage in the frontto-rear median plane thereof and arranged to engage said cam edges, an auxiliary cam follower mounted on said carriage between said pair of followers, and an auxiliary cam on said pedestalengageable by said auxiliary follower, said cams being arranged and shaped so that one of said pair of followers serves as a center of rotation for the initial and final portions of the reversing movement of the carriage, and the axis of rotation shifts progressively from said one follower toward the other and back during the intermediate portion of the reversing movement of the carriage.

3. A reversing car-seat base comprising a stationary pedestal, a seat carriage movable thereon and means for guiding reversing movement of said carriage on said pedestal, said guiding means including a series of three cam followers mounted on said carriage in the longitudinal median thereof, a pair of sockets on said pedestal normally engaged by the end followers of said series, a pair of arcuate cam surfaces concentric respectively with said sockets and engageable by one of said end followers to maintain the other end follower in said sockets to act as a pivot during the initial and final portion of a reversing movement, and an auxiliary cam surface engageable by the intermediate follower of said series and shaped to shift the pivot axis of the seat by stages away from and back to said other end follower during the intermediate portion of the reversing movement.

4. A reversing car-seat base comprising a stationary pedestal with a horizontal top, a seat. carriage supported on said top and rotatable between two oppositely facing positions for use, a pair of cam followers on said carriage arranged in the front-to-rear median plane thereof when the carriage is in either of its positions for use, an auxiliary cam follower mounted on said carriage between said pair, and cam means on said pedestal engageable by'said followers to guide the reversing movements of said carriage so that one of said pair of followers acts as a turning pivot for the initial and final portion of reversing movements of said carriage and the center of the carriage follows a path in which there is no and arranged so that the center of rotation ofthe carriage is initially in one of said pair of cam followers and shifts successively, during a reversing movement of said auxiliary follower, the

- other of said pair back to said auxiliary follower and then to said one follower for the final portion of the reversing movement.

OIVA E. HILL.