US3012817A

US3012817A - Reversible chair for vehicles

Info

Publication number: US3012817A
Application number: US858375A
Authority: US
Inventors: Severin B Hendrickson; Reid Edward Harry
Original assignee: Heywood Wakefield Co
Current assignee: Heywood Wakefield Co
Priority date: 1959-12-09
Filing date: 1959-12-09
Publication date: 1961-12-12
Anticipated expiration: 1978-12-12

Description

Dec. 12, 1961 S. B. HENDRICKSON ETAL REVERSIBLE CHAIR FOR VEHICLES Filed Dec. 9, 1959 2 Sheets-Sheet 1 3o 28 //%7L" l-- l8 as FIG.3

INVENTORS SEVERIN B. HENDRICKSON BE DWARD HARRY REID KMJWM ATTO R N EYS Dec. 12, 1961 S. B. HENDRICKSON ETAL REVERSIBLE CHAIR FOR VEHICLES 2 Sheets-Sheet 2 Filed Dec. 9, 1959 INVTOR HEN 5 EV RIN B RICKSON B EEPW ARD HARRY RBD 1 5% fimea m AT TORNEXSE United States Parent 3,012,817 REVERSIBLE CHAIR FOR VEHICLES Severin B. Hendrickson, Templeton, and Edward Harry Reid, Gardner, Mass, assignors to Heywood-Wakefield Company, Gardner, Mass, a corporation of Massaelnlsetts Filed Dec. 9, 1959, Ser. No. 858,375 2 Claims. (Cl. 297-93) This invention relates to vehicle chairs, and more particularly to reversing mechanisms for such chairs.

Over the years one of the most successful reversible chairs for vehicles has been the so-called walk-over type. Its construction and operating mechanisms have remained essentially without change or basic improvement for many years even though it has several important disadvantages. Our invention described and claimed herein is directed generally to the object of providing an improved reversible chair for vehicles for uses similar to those for which the walk-over type chair has hitherto been used but which avoids some of its more undesirable aspects.

Among the several drawbacks of the walk-over type chair is that the seat portion of the chair must be tilted forward or backward whenever the backrest is shifted in order to provide a rearward tilt to the seat portion of v the chair. This requirement calls for complex linkage and moving elements beneath the seat arranged to operate in response to the reversing motion of the back rest. Another drawback of the walk-over chair relates to the surfaces against which the occupant sits. In the walkover chair the back rest element must have both its back and its front surfaces finished in a manner suitable for personal contact because the back rest reversing motion brings one or the other side of the back rest into the chair occupancy zone.

Accordingly, it is an object of our invention to provide a chair mounted on a single fixed base together with a simple mechanism for reversing the direction of the chair. A further object is to provide such a chair with a single reversing linkage arrangement which both reverses the position of the back rest portion of the chair and reverses the tilt of the seat portion thereof from the horizontal to provide an upward tilt or slant for the seat for either direction of the chair. Another object is to provide a chair adapted for reversal of direction and requiring only one back rest surface to be finished in a manner suitable for personal contact.

In the accomplishment of these and other objects of our invention in a preferred embodiment thereof, we mount a one piece chair on a linkage arrangement pivoted to a fixed base. The chair comprises a frame supporting a one-piece molded combined seat portion and back rest portion at generally right angles to each other. The seat and back rest portions are identical to each other in size, shape and contour so that they are functionally interchangeable, and the angle between them is'fixed. In position onthe base, the back rest tilts backwardly from the vertical and the seat upwardly from the horizontal about 12 /2. The linkage arrangement which supports the chair is adapted to shift the lower rear corner of the chair on the base from one upper edge of the base to the other upper edge thereof while pivoting the chair in the reverse direction through an arc of about 65". In this way the back rest becomes the seat and vice versa, and in its new position the seat assumes the proper angle and the chair remains substantially centered over the base. Also the same back rest and chair surfaces face the occupancy zone, and these things are all accomplished with only one extremely simple linkage arrangement.

Other features of our invention relate to the support 3,012,817 Patented Dec. 12, 1961 for the chair and to the positioning of the linkage pivot points in order to result in the desired sequence of motions during the reversing action. The support for the chair is distributed between an intermediate cross-bar within the chair frame, portions of the pivot linkage, and a rear support abutment that buttresses the rearmost member of the linkage assembly. In this way no single element receives undue stress. In addition, the sequence of motions during reversal is also significant. The pivot points are arranged so that the initial reversing motion of the chair is to tilt the back rest back and raise the seat to a point where one of the links rides over center. This is a safety feature because it prevents inadvertent chair reversal due to pressure on the back rest while the chair is occupied, but does not interfere with intentional reversal brought about by lifting the seat portion. We provide additionally a hold-down latch for holding the seat in position, but even if the hold-down latch is not engaged, the weight of the occupant prevents the links from riding over center and thereby prevents the chair from reversing;

Other objects and features of our inventionwill best be understood and appreciated from a detailed description of a preferred embodiment thereof, selected for purposes of illustration and shown inthe accompanying drawings, in which: I

FIG. 1 is a view in perspective of the chair of our invention; I

FIG. 2 is a view in side elevation showing the reverse position for the chair in dotted lines;

FIG. 3 is a view in rear elevation;

FIG. 4 is a perspective view of the linkage and chair support elements; and

FIG. 5 is a view in side elevation showing the linkage and chair support elements in more detail.

The preferred embodiment of our invention herein shown includes in its general organization a tubular base indicated at 10 and a chair of L-shaped cross-section mounted thereon and indicated at 12; i

The base 10 is secured to the floor ofa vehicle or the like, and is usually positioned so that it extends trans.- versely from the center aisle of the vehicle to a point adjacent to one sidewall thereof. As shown, the base 10 is of tubular construction and includes a pair of inverted U-shaped side standards 14 joined by transverse cross bars 16 which also serve as foot rails. The side standards 14 each support a chair support pan 18, which is bolted to an angle iron 20 which is in turn welded to the top of each side standard 14.

The chair 12 comprises a tubular frame having side bars 22, top cross bars 24 at each end, and intermediate cross bars 26. The frame supports a one-piece molded fiberglass chair surface which is dimensioned and. contoured to provide identical back rest and seat portions set at approximately right angles to each other. When in position for use the seat portion is tilted upwardly from the horizontal at an angle of about 12% and the back rest tilts backwardly about 12 /2 from the vertical.

The chair 12 is supported on the base 10 by means of a pair of pivot links 28 at each end of the chair. The links 28 are pivoted to the side bars 22 of the chair at 30 and to the base support pans at 32. They are arranged to shift the lower rear corner of the chair indicated at 34 (see FIGS. 2 and 5) from one upper edge of the base 10 to the other upper edge while pivoting the chair through about 65 of arc in the reverse direction (see dotted lines in FIG. 2). This motion is accomplished first by determining the desired angle of backward tilt for the chair. Once this is determined the necessary number of degrees for the reverse pivoting motion of the chair is less twice that angle. Then, having selected a convenient location and spacing for the pivots 32, the chair is placed or drawn) in position on the base facing in one direction and tilting backwardly at the said desired angle. Thereafter a line is drawn from the forwardmost pivot 32 rearwardly and upwardly at an angle equal to one half the reverse pivot angle for the chair to the place where it intersects the side bar 22 above and to the rear of the lower rear corner 34 of the chair 12. That point of intersection then becomes the location of the upper rearmost pivot 30, and the length of the links 28 becomes the distance between that point and the rearmost pivot 32. Both links 28 are identical and the other pivot 30 is thereby located on the side bar 22 a corresponding distance from the said forward pivot 32 and equidistant from the lower rear corner 34 of the chair 12 but on the opposite side thereof. With the links 28 so pivoted, the chair 12 will pass through a reverse pivot arc of the desired amount and the lower rear corner 34 of the. chair 12 will assume the symmetrically opposite position relative to the base after the pivot is completed.

In the preferred embodiment of our invention herein shown, we prefer to have the chair pivot through a few more degrees of arc than is determined by the above analysis of pivot locations and link dimensions. Thus the forwardmost link 28 (in a given directional position for the chair) pivots beyond a straight line between its pivot 32 and the pivot 30 of the rearmost link 28. This extra pivotal motion has several beneficial aspects. In the first place, it facilitates the engagement of a hold-down latch indicated at 36 by ensuring a nearly vertical downward sweep of the forward edge of the seat for the last few degrees of its travel. The more nearly vertical such mo- 'tion is, the better it is for latch operation. Second, this motion is also a safety feature because it virtually prevents inadvertent chair direction reversal due to forces applied to the back rest. With such forces, especially when the chair is occupied, it is almost impossible to lift the foremost link 28 over center and then push the seat into reversing position. On the other hand, when one desires to reverse direction of the chair intentionally, the latch 36 is released at the lower forward portion of the seat, and the seat portion is lifted to bring it into its new position as a back rest. Such motion easily brings the forward link 28 through center and causes the shift of the chair across the base while pivoting.

The latch 36 includes a hand grip 38 integrally connected to a plunger 40 which is spring loaded and snaps into a hole 42 (see FIG. 4) in a small upstanding metal plate 44 mounted at each end of each support pan 18. The plates 44 tilt backwardly at an angle slightly greater than the direction of downward pivotal motion of the seat during the final few degrees of its travel. In this way the plunger 40 rides onto the plates 44 at a wedging angle and is gradually forced backwardly until the plunger 40 is in registration over the hole 42, at which point it snaps in place. Concurrently with the engagement of the latch 36, the intermediate bar 26 associated therewith descends into contact with a rubber pad 46 mounted on a lower horizontal segment of the base of plates 44. In this way the forward portion of the seat is actually supported on a rubber pad and the noise of the seat snapping into place is accordingly mufiled by such metal-to-rubber contact. In addition, however, it should be noted that the latch 36 likewise will share a portion of any downward forces which are great enough to force down and compress the pad 46. In this way the pad 46 is saved from being crushed by excessive forces. In addition, for shock absorption purposes, we provide a rubber pad 48 mounted on each link 28 and in position to contact the end wall of the base support pans 18 when a respective link 28 is serving as the rearmost link in the arrangement (see for instance the right-hand links 28 in FIGS. 4 and 5). The pads 48 also serve an important function in relation to the above described action of the forwardmost link 28 in pivoting beyond center. Bearing in mind that the final pivotal motion of the chair is to bring the forwardmost link 28 beyond the straight line between its lower pivot 30 and the upper pivot 32 of the other link, final motion of the chair is to bring the back rest forward slightly. The same motion takes place at the start of reversal and it results in compressing the rearmost pad 4-8 against the rear wall of the support pan 18. However, the links are arranged so that when the chair is in position for use the pad 48 at the rear still bears some of the pressure of the weight of the occupant, and this weight is in fact distributed across the base starting at the rearmost pad 48, thence forward to both pivots 32, and finally to the forwardmost pad 46.

Since numerous minor modifications and changes in the preferred embodiment of our invention herein shown will now be apparent to those skilled in the art, it is not our intention to confine the invention to the precise form herein shown, but rather to limit it in terms of the appended claims.

Having thus described and disclosed a preferred embodiment of our invention, what we claim as new and desire to secure by Letters Patent of the United States is:

l. A reversible chair for vehicles comprising: a base, a one-piece L-shaped chair element having its two leg members of symmetrical construction so that either may be used as a seat portion, the other leg acting as a back rest; means for mounting said chair element on said base comprising a pair of link members pivotally attached to said base and said chair element on each side thereof, said link members being attached to said base at points equidistant on each side of the transverse centerline of said base, and attached to said chair element at points likewise equidistant on each side of the transverse centerline of said chair element, said attachment points on said chair element being less widely spaced apart than said attachment points on said base; latch means at each extremity of said chair element, each comprising a spring loaded plunger attached to said chair element at each extremity thereof; a cooperating bracket attached to said base at each extremity thereof positioned to engage said spring loaded plunger when said chair element is positioned for occupancy; means associated with said spring loaded plunger to disengage said plunger from said bracket when it is desired to release said chair element for reversal; and means including resilient pads for steadying said chair element against motion relative to said base when said chair element is in position for use.

2. A reversible seat for vehicles as defined in claim 1 further characterized by said last mentioned means comprising; brackets positioned at each extremity of said base to engage said chair element toward the forward end thereof; shock absorbing means comprising compressible pads positioned on each said bracket to cushion said chair element while resting on said bracket; shock absorbing means comprising compressible pads mounted on the outer faces of said link members and positioned thereon to engage said base when said link member is serving as the rearmost link.

References Cited in the file of this patent UNITED STATES PATENTS 551,326 Norcross Dec. 10, 1895 789,248 Ackerly May 9, 1905 814,514 Budd Mar. 6, 1906 2,858,880 Fox Nov. 4,, 1958