Reclining Seat Adjuster

Abstract

Irreversible epicyclic gearing connects the seat back to the seat and includes a manually rotatable shaft having an eccentric portion on which is mounted a drive gear engaged in an internal gear carried by the seat or seat back member and having limited lost motion connection with the other member.

Description

CROSS-REFERENCE TO RELATED PATENT

The present application is related to my prior U.S. Pat. No. 3,423,785.

BRIEF SUMMARY OF THE INVENTION

The present construction provides a manually adjustable seat back intended to be moved from normal upright position to rearwardly extending reclining position. Associated with the pivot connection between the seat back and the seat is epicyclic gearing.

Substantially identical bracket constructions are provided at each side of the seat and serve to interconnect a fixedly mounted seat member with a pivotally mounted seat back member. One of the members includes an internal gear which preferably is formed by a partial stamping operation, leaving the partially stamped-out material connected to the member as a generally annular abutment closing one end of the tooth spaces. Received in the recess thus formed is a drive gear having a few less teeth than the internal gear. The drive gear is provided with a circular array of openings extending about the axis of the drive gear.

The drive gear is mounted on an eccentric portion of a shaft constituting a part of the pivot connection between the members.

The other member is provided with pin-like elements extending into the openings in the drive gear with substantial lost motion.

As a result, rotation of the drive shaft causes an oscillating movement of the drive gear and each oscillation effects relative angular movement between the members in accordance with the difference in number of teeth of the internal and drive gears.

The epicyclic gearing thus provided is irreversible so that rotation of the shaft is required to effect movement of the seat back either forwardly or rearwardly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary side elevation of the bracket members constituting portions of the seat and seat back.

FIG. 2 is a sectional view on the line 2--2, FIG. 1.

FIG. 3 is a sectional view on the line 3--3, FIG. 2.

FIG. 4 is a fragmentary elevational view of a second embodiment of the invention.

FIG. 5 is a sectional view on the line 5--5, FIG. 4.

FIG. 6 is a sectional view on the line 6--6, FIG. 5.

DETAILED DESCRIPTION

Referring first to FIGS. 1-3, the reclining seat back construction comprises a hinge or pivot mounting between a seat member 10 and a seat back member 12. These members are preferably formed of flat metal which is referred to herein as "plate-like." The distinction between plate and sheet is not strictly observed although sheet is sometimes described as having a thickness of not more than one-fourth inch. In the present case, the material of the bracket members 10 and 12 may be less than one-fourth inch as for example, about three-sixteenths inch, but in the dimensions in which the material is used, the material is substantially rigid.

On the other hand, as will subsequently appear, one of the brackets may be formed of a substantially thinner material adapted to be shaped to relatively abrupt contours and this material is referred to as "sheet" material. This material may for example be considered as having a thickness of approximately one-sixteenth inch.

One of the members, as for example the seat back member 12, is provided with a recess 14, the peripheral portion of which is shaped to form an internal gear having the teeth as best indicated at 16 in FIG. 3. This construction may advantageously be made by a stamping operation in which the recess 14 is formed by displacing or extruding the material to form a displaced abutment wall 18 which forms a bottom to the recess 14, but leaves the displaced material connected to the plate-like member 12 as indicated at 20. It will be appreciated that with this construction the outer surface of the displaced material will have a toothed configuration as best illustrated at 22 in FIG. 1 although the gear formed by these teeth do not enter functionally into operation of the seat recliner.

Received in the recess 14 is an annular drive gear 24, the construction of which is best apparent in FIG. 3. The drive gear 24 includes a circular central opening 26 and disposed in a circular array about the axis of the drive gear are a multiplicity of enlarged circular openings 28. The bracket member 10 forming a part of the seat has a central opening 30 and disposed about the central opening 30 in concentric relation thereto is a circular array of laterally projecting pin-like elements 32. These elements are preferably formed by a partial stamping operation somewhat similar to the operation employed in producing the internal gear recess 14, and results in the formation of non-functional recesses 34 at one side of the member 10. The circular elements 32 extend into the circular openings 28 with substantial lost motion for a purpose which will presently appear.

A drive shaft indicated generally at 36 is provided having a flange 38, circular bearing surfaces 40 and 42, and an eccentric circular bearing surface 44.

As best seen in FIG. 2, the members 10 and 12 are journaled on the coaxial bearing surfaces 40 and 42 and the drive gear 24 is rotatably mounted on the eccentric shaft portion 44.

The diameter of the openings 28 exceeds the diameter of the pin-like elements 32 by twice the amount of the eccentricity of the shaft portion 44.

The drive gear 24 has a number of teeth slightly less than the number of teeth in the internal gear 16 with the result that the gears 16 and 24 mesh in the relationship illustrated in FIG. 3. From this Figure it will be apparent that one rotation of the shaft 36, which may be accomplished by a handle or crank as indicated at 46, will effect relative angular movement between the members 10 and 12 in accordance with the difference in the number of teeth. The difference in the number of teeth represents a small fraction of the total number of teeth in the internal gear 16. Accordingly, several rotations of the shaft 36 will be necessary to produce a 90.degree. adjustment of the seat back from vertical to horizontal position.

As a result of this gear arrangement, it will be appreciated that the gearing is irreversible so that the seat back will remain in any position to which it is adjusted by rotation of the shaft, and conversely, manual rotation of the shaft is required to effect adjustment of the seat back.

With the construction as just described it will be observed that the operating structure at the pivot connection, with the exception of the shaft 36, is approximately equal to the combined thicknesses of the plate-like material from which the members 10 and 12 and the gear 24 are fabricated.

It will further be appreciated that similar hinge and pivot means are provided at opposite sides of the seat and for this purpose rotation may be imparted to a second bracket by means of a torsion bar indicated at 48, which as illustrated is of square cross-section.

The shaft 36 carries a washer 49 which engages the outer surface of the displaced abutment wall 18, this washer being retained in place by upsetting the adjacent end of the shaft 36 as illustrated in FIG. 2. With this arrangement it will be seen that the bracket member 10 mounts the shaft in a fixed position and the shaft in turn constitutes the guiding support which locates both the drive gear 24 and the seat back bracket member 12.

Referring now to FIGS. 4-6 there is illustrated a somewhat different embodiment of the 3, in which the seat bracket indicated generally at 50 is formed of an assembly of two concave stampings 52 and 54 assembled together to provide an effectively rigid supporting bracket. The seat back member 56 may in this embodiment of the invention be identical with that illustrated at 12 in FIGS. 1-3, and the drive gear 58 and shaft 60 may also be identical.

In this construction the upper end of the stampings 52 and 54 are interconnected by rivets 62 which form pin-like elements performing the functions of the elements 32 in the previously described embodiment of the invention. These elements not only serve the function of establishing a driving relation with the drive gear 58, but also of course serve as the means both interconnecting and spacing the upper ends of the stampings 52 and 54.

Rotation of the shaft 60 results in oscillation of the drive gear 58 and produces angular movement between the members 50 and 56.

In this construction a different guiding support is provided intermediate the members 50 and 56. The member 50 journals the shaft 60 at the two coaxial cylindrical journal portions 64 and 66. However, the seat back bracket member 56 is in this case guidingly connected to and supported by the member 50 by reason of a cylindrical flange 68 which engages around a substantial portion of the toothed periphery of the laterally displaced abutment wall 70. In addition, the stamping 54 is provided with an arcuate depressed portion 72 forming a generally cylindrical guide wall 74 which engages a portion of the crests of the teeth on the abutting wall 70 substantially opposite the flange 68.

It will of course be understood that the drive gear 58 is journaled on the eccentric portion 76 of the shaft 60 but since this gear is in mesh with the internal gear 78 provided in the seat back member 56, it cannot provide the necessary guidance for swinging movement of the seat back.

It will be observed that in this embodiment of the invention the overall thickness of the mechanism provided at the pivot connection, exclusive of the shaft 64, is again substantially equal to the combined thickness of the material of the drive gear 58, the member 56, and the combined thickness of the two stampings 52 and 54.

It will further be observed that in both cases the drive gear has opposite flat side surfaces which respectively engage a confronting surface of one of the bracket members 10 or 50 and the confronting surface of the abutment wall 18 or 70.

Claims

What I claim is:

1. Adjustable support structure for a seat back of a reclining seat comprising

a stationary support member,

an arm member pivoted to said stationary support member,

pivot means comprising a rotatable shaft connecting said members, said shaft having a circular cross-section first portion defining the pivot axis between said members, and a circular cross-section second portion eccentric to said first portion,

irreversible drive gearing connecting said members comprising

an externally toothed annular drive gear rotatable on the eccentric portion of said shaft and having a series of circular openings disposed in a circular array around and concentric with said eccentric portion,

one of said members having an internally toothed recess constituting an internal gear and receiving said drive gear in mesh therewith, the number of teeth in said internal gear exceeding the number of teeth in said drive gear by a small number representing a small fraction of the total number of teeth in said recess,

said other member having a circular array of pin-like elements extending into said circular openings, the diameter of said array being equal to the diameter of the circular array of openings in said drive gear, the diameter of said circular openings exceeding the diameter of said elements by double the eccentricity of the eccentric portion of said shaft,

said one member being formed of flat metal plate-like material,

and an annular abutment on said one member closing one end of the internal gear and serving to engage one side of said drive gear to limit axial movement thereof in one direction,

said other member having an annular portion positioned to engage the other side of said drive gear to limit axial movement thereof in the other direction,

and manually operated means for rotating shaft shaft.

2. Structure as defined in claim 1 in which said internal gear and said annular abutment are both formed from unitary rigid plate-like material, and said abutment is a gear shape laterally stamped partially from but not severed from the sheet material.

3. Structure as defined in claim 1 in which said other member is formed of plate-like material and said pin-like elements are stamped extrusions extending laterally from one side of said other member.

4. Structure as defined in claim 2 in which said other member is formed of plate-like material and said pin-like elements are stamped extrusions extending laterally from one side of said other member.

5. Structure as defined in claim 4, said drive gear being formed of plate-like metal of about the same thickness as said members and having opposed flat surfaces in sliding contact with the confronting surface of the annular abutment on said one member and the side of said other member, whereby the operating structure at the pivot connections between said members exclusive of said shaft has an overall thickness about equal to the combined thickness of said members and drive gear.

6. Structure as defined in claim 2, said other member comprising substantially paired concave shaped portions, one of said portions having a substantially cylindrically shaped flange guidingly engaging the crests of the teeth of said gear-shaped stamping.

7. Structure as defined in claim 6, said one concave shaped portion having an inwardly formed arcuate portion having an arcuate generally cylindrical area guidingly engaging the crests of the teeth of said gear-shaped stamping in a zone generally opposite the zone thereof engaged by said flange.

8. Structure as defined in claim 1, the annular abutment on said one member having a generally cylindrical outer peripheral portion, said other member comprising substantially paired concave shaped portions, one of said portions having a substantially cylindrically shaped flange guidingly engaging the outer peripheral portions of said abutment.

9. Structure as defined in claim 8 in which said concave shaped portions are formed of sheet material having stiffening flanges around their edge portions.

10. Structure as defined in claim 9 in which said pin-like elements extend between and rigidly interconnect said concave shaped portions.

11. Structure as defined in claim 8, said one concave-shaped portion having an inwardly formed arcuate portion having an arcuate generally cylindrical area guidingly engaging the outer peripheral portions of said abutment in a zone generally opposite the zone thereof engaged by said flange.