Foldable armrest for a seat having a collapsible back

Information

  • Patent Grant
  • 6739669
  • Patent Number
    6,739,669
  • Date Filed
    Thursday, May 23, 2002
    22 years ago
  • Date Issued
    Tuesday, May 25, 2004
    20 years ago
Abstract
A foldable armrest unit for a seat having a collapsible seat back, including an armrest one end of which is articulated to first joint device affixed to a lateral surface of the seat back, the armrest unit further including an armrest support member, one end of which is articulated to the armrest and the other end of which is articulated to second joint device affixed to a lateral surface of the seat; the armrest having three limit positions: a first limit position being the position of use, in which the seat back is in an upright position and the armrest is in a substantially horizontal position; a second limit position in which the seat back is still in the upright position, while the armrest is swung towards the seat back to facilitate access to and egress from the seat, and a third limit position in which the armrest is completely folded down, together with the collapsed seat back.
Description




FIELD OF THE INVENTION




The present invention relates to a foldable armrest unit for a seat having a collapsible back.




BACKGROUND OF THE INVENTION




Seats having collapsible backs are used in small powered vehicles for the elderly or handicapped, and may be folded for storage. In the past, such seats had armrests that had to be dismounted prior to folding or storing and remounted prior to use. In other types of seats the armrest or armrests had to be lifted or lowered for seat access independent of seat folding.




DISCLOSURE OF THE INVENTION




It is thus one of the objects of the present invention to provide an armrest unit that is an integral part of the seat, will automatically fold down when the seat back is collapsed, and will be restored to its working position when the seat back is raised.




It is a further object of the present invention to provide an armrest unit that can be swung out of the way to facilitate comfortable access to and egress from the seat.




It is yet another object of the present invention to provide means for preventing pressure exerted on the armrest unit from inadvertently initiating collapse of the seat back.




According to the invention, the above objects are achieved by providing a foldable armrest unit for a seat having a collapsible seat back, comprising an armrest, one end of which is articulated to first joint means affixed to a lateral surface of the seat back, comprising an armrest support member, one end of which is articulated to the armrest and the other end of which is articulated to second joint means affixed to a lateral surface of the seat; the armrest having three limit positions: a first limit position being the position of use, in which the seat back is in an upright position and the armrest is in a substantially horizontal position; a second limit position in which the seat back is still in the upright position, while the armrest is swung towards the seat back to facilitate access to and from the seat, and a third limit position in which the armrest is completely folded down, together with the collapsed seat back.











BRIEF DESCRIPTION OF THE DRAWINGS




The invention will now be described in connection with certain preferred embodiments with reference to the following illustrative figures, so that it may be more fully understood.




With specific reference now to the figures in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.




In the drawings:





FIG. 1

illustrates the armrest unit according to the present invention, in its first limit position;





FIG. 2

illustrates the armrest unit in its second limit position;





FIG. 3

illustrates the armrest unit in its third limit position;





FIG. 4

is a partial cross-sectional view of the armrest of the invention;





FIG. 5

is a cross-sectional view along plane V—V of

FIG. 4

;





FIGS. 6



a


and


6




b


are cross-sectional views along planes VIa and VIb, respectively, of

FIG. 4

;





FIGS. 7 and 8

represent two views of the outer telescoping tube of the armrest support member;





FIG. 9

is a cross-sectional view of the inner telescoping tube of the armrest support member;





FIG. 10

represents a front view of the upper joint of the armrest;





FIG. 11

is a cross-sectional view along plane XI—XI of

FIG. 10

;





FIG. 12

is a front view of the upper joint of the armrest;





FIG. 13

is a front view of the lower joint of the armrest, and





FIG. 14

is a cross-sectional view along plane XIV—XIV of FIG.


13


.











DETAILED DESCRIPTION




Referring now to the drawings, there is shown in

FIG. 1

an armrest unit


1


, comprising an armrest


2


, articulated to an upper joint


4


fixedly attached to a lateral surface of the collapsible back


6


of a seat


8


. Armrest


2


is also provided with padding


10


.




Further shown is a support member


12


, which, as seen to better effect in

FIG. 2

, consists of two telescoping tubular elements: an inner tube


14


, the lower end of which is articulated to a lower joint


16


fixedly attached to a lateral surface of seat


8


, and an outer tube


18


, the upper end of which is articulated to armrest


2


.

FIG. 1

shows the armrest according to the invention in the first of three limit positions, which is the position in which the seat is used.





FIG. 2

shows the armrest


2


in its second limit position, in which support member


12


is swung back towards seat back


6


to facilitate access to and egress from the seat


8


. It is clearly seen that the change of length of support member


12


, involved in the movement of armrest


2


from the position shown in

FIG. 1

to that shown in FIG.


2


and back again, is accommodated by the relative movement of telescoping tubes


14


and


18


. Once seated, the user pushes the raised armrest


2


back to the position illustrated in FIG.


1


.





FIG. 3

illustrates the third limit position of armrest


2


, arrived at when seat back


6


is collapsed by pushing it in the direction of arrow A, automatically causing the armrest


2


to fold and assume the position shown. Obviously, pulling the collapsed seat back


6


in the opposite direction will re-erect it and will also automatically restore armrest


2


to the position shown in FIG.


1


.





FIGS. 4 and 5

illustrate armrest


2


, which has the form of a tubular member having a bent end portion to which is welded a solid end piece


20


with a countersunk bore


22


, whereby armrest


2


is articulated to a pivot provided on upper joint


4


(FIG.


10


). Also seen is a pin


24


projecting from end piece


20


. In the assembled state of armrest


2


, pin


24


projects into an annular recess of limited angular extent provided in upper joint


4


(FIG.


10


), constituting a stop limiting the folding and unfolding movement of the armrest.




Further shown are diametral holes


26


, serving screws for affixing the padding


10


. Another diametral hole


28


and an elongated opening


30


serve for the articulation of the upper end of outer telescoping tube


18


.





FIGS. 6



a


and


6




b


are cross-sectional views of padding


10


, attached to armrest


2


by means of screws.





FIGS. 7 and 8

depict the outer telescoping tube


18


. Seen is a head piece


32


welded to tube


18


and provided with a flat nose


34


which, in assembly, enters armrest


2


through elongated opening


30


(

FIG. 1

) and is articulated to armrest


2


by means of a pivot (not shown) passing through holes


36


and


28


(FIG.


4


). The lower end of tube


18


is provided with a slot


38


which can slip freely over the pivot in lower joint


16


. Also seen is a pin


40


, the purpose of which will be discussed below in conjunction with FIG.


13


.





FIG. 9

represents inner telescoping tube


14


, which is seen to have a lower, metallic end piece


42


welded to tube


14


and provided with a countersunk bore


44


, whereby inner tube


14


is articulated to a pivot provided on lower joint


16


(FIG.


14


). The upper end of tube


14


is provided with a plug


46


, slidingly fitting the inside diameter of outer telescoping tube


18


and advantageously made of one of the low-friction plastics. Two oppositely located slots


48


cut in plug


46


permit the passage of air during the folding and unfolding movements of armrest


2


. To ensure a smooth, substantially free fit between tubes


14


and


18


in their fully telescoped position, the end portion


50


of end piece


42


is slightly tapered, ensuring the lateral stability of the armrest in its position of use.





FIGS. 10

to


12


represent the upper joint


4


, which is seen to comprise a base plate


52


affixed to a lateral surface of seat back


6


by means of screws passing through countersunk holes


54


. A top plate


58


, provided with an annular recess


60


of a limited angular extent, is welded to base plate


52


through holes


56


. In assembly, pin


24


of armrest


2


(

FIG. 5

) projects into recess


60


, whereby the folding and unfolding movements of armrest


2


are delimited. Also welded to base plate


52


is pivot


62


, on which armrest


2


is mounted and swivels, retained by a screw (not shown). It will be appreciated that pivot


62


with base


52


includes an angle larger than 90°, to compensate for the draft of the lateral surfaces of the plastic molding of seat back


6


.





FIGS. 13 and 14

represent lower joint


16


, which is seen to comprise a base plate


64


, countersunk holes


66


for screws (not shown), and a pivot


68


welded to base plate


64


. Inner telescoping tube


14


(

FIG. 1

) is mounted on and swivels about pivot


68


, retained by a screw (not shown). Also welded to base plate


64


is an abutment member


70


having a substantially planar surface


72


which, in assembly, is inclined with respect to the general plane of seat


8


but is substantially perpendicular to the lateral surface on which joint


16


is mounted. This inclined surface cooperates with pin


40


of outer telescoping tube


18


(

FIGS. 1

,


7


) to the effect of preventing the collapse of seat back


6


upon the application of pressure to armrest


2


, but allowing pin


40


to ride along planar surface


72


, facilitating such collapsing when a tilting force is applied to seat back


6


.




Pivot


68


and abutment member


70


, with lower joint


16


and base plate


64


, include an angle larger than 90°, for the same reason given above with regard to upper joint


4


.




It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrated embodiments and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.



Claims
  • 1. A foldable armrest unit attached to a seat having a collapsible seat back, comprising:an armrest, one end of which is articulated to first joint means affixed to a lateral surface of said seat back; an armrest support member, one end of which is articulated to said armrest and the other end of which is articulated to second joint means affixed to a lateral surface of said seat; said armrest has three limit positions: a first limit position being the position of use, in which said seat back is in an upright position and said armrest is in a substantially horizontal position; a second limit position in which said seat back is still in the upright position, while said armrest is swung towards said seat back to facilitate access to, and egress from, said seat, and a third limit position in which said armrest is completely folded down, together with the collapsed seat back and wherein said armrest support member is constituted by a pair of telescoping tubes accommodating the change of length of said support member involved in the movement of said armrest from said first limit position to said second limit position and back again, one of said telescoping tubes being articulated to said armrest and the other being articulated to said seat.
  • 2. The armrest unit attached to the seat as claimed in claim 1, wherein one end of the armrest support member is connected to the armrest around a middle section of the armrest.
  • 3. The armrest unit attached to the seat as claimed in claim 1, further comprising a pin fixedly attached to the outer one of said telescoping tubes, said pin cooperating with abutment means stationary relative to said seat to prevent the initiation of collapse of said seat back by the application of pressure on said armrest.
  • 4. The armrest unit attached to the seat as claimed in claim 3, wherein said abutment means comprises a member fixedly attached to said second joint means and provided with a substantially planar surface inclined with respect to the general plane of said seat, but substantially perpendicular to the lateral surface thereof, said inclined surface cooperating with said pin to prevent the collapse of said seat back upon the application of pressure to said armrest but permitting such collapse when a tilting force is applied to said seat back.
  • 5. The armrest unit attached to the seat as claimed in claim 1, wherein said first and second joint means are each provided with a pivot about which said armrest and said support member are respectively adapted to swivel.
  • 6. The armrest unit attached to the seat as claimed in claim 5, wherein said pivots include, along with bases of their respective joint means, angles larger than 90 °.
  • 7. A foldable armrest unit for use with a chair having a seat and a collapsible seat back, the armrest unit comprising:an armrest, one end of which is articulated to first joint means adapted to be affixed to a lateral surface of said seat back; an armrest support member, one end of which is articulated to said armrest and the other end of which is articulated to second joint means adapted to be affixed to a lateral surface of said seat; wherein one end of the armrest support member is connected to the armrest around a middle section of the armrest; and wherein said armrest has three limit positions: a first limit position being the position of use, in which said seat back is in an upright position and said armrest is in a substantially horizontal position; a second limit position in which said seat back is still in the upright position, while said armrest is swung towards said seat back to facilitate access to, and egress from said seat, and a third limit position in which said armrest is completely folded down, together with the collapsed seat back.
  • 8. A foldable armrest unit for use with a chair having a seat and a collapsible seat back, the armrest unit comprising:an armrest, one end of which is articulated to first joint means adapted to be affixed to a lateral surface of said seat back; an armrest support member, one end of which is articulated to said armrest and the other end of which is articulated to second joint means adapted to be affixed to a lateral surface of said seat; wherein said armrest support member is constituted by a pair of telescoping tubes accommodating the change of length of said support member adapted to movements of said armrest, wherein one of said telescoping tubes is adapted to be connected to said armrest, and the other is adapted to be connected to said seat; and wherein said armrest has three limit positions: a first limit position being the position of use, in which said seat back is in an upright position and said armrest is in a substantially horizontal position; a second limit position in which said seat back is still in the upright position, while said armrest is swung towards said seat back to facilitate access to, and egress from, said seat, and a third limit position in which said armrest is completely folded down, together with the collapsed seat back.
  • 9. The armrest unit as claimed in claim 8, wherein one end of the armrest support member is connected to the armrest around a middle section of the armrest.
  • 10. The armrest unit as claimed in claim 8, further comprising a pin fixedly attached to the outer one of said telescoping tubes, said pin engagable with abutment means stationary relative to said pin to prevent the initiation of collapse of said armrest by application of pressure on said armrest.
  • 11. The armrest unit as claimed in claim 8, wherein said first and second joint means are each provided with a pivot about which said armrest and said support member are respectively adapted to swivel.
  • 12. The armrest unit as claimed in claim 11, wherein said pivots include, along with bases of their respective joint means, angles larger than 90 °.
  • 13. A foldable armrest unit attached to a seat having a collapsible back, comprising:an armrest, one end of which is articulated to first joint means affixed to a lateral surface of said seat back; an armrest support member, one end of which is articulated to said armrest and the other end of which is articulated to second joint means affixed to a lateral surface of said seat; wherein one end of the armrest support member is connected to the armrest around a middle section of the armrest; and wherein said armrest has three limit positions: a first limit position being the position of use, in which said seat back is in an upright position and said armrest is in a substantially horizontal position; a second limit position in which said seat back is still in the upright position, while said armrest is swung towards said seat back to facilitate access to, and egress from, said seat, and a third limit position in which said armrest is completely folded down, together with the collapsed seat back.
US Referenced Citations (9)
Number Name Date Kind
1291413 Cluff, Jr. Jan 1919 A
2689600 Van Briesen Sep 1954 A
3661421 Johnson May 1972 A
3806192 Ohlrogge et al. Apr 1974 A
4097088 Meiller Jun 1978 A
4307913 Spiegelhoff Dec 1981 A
4639012 Jensen Jan 1987 A
4887866 Rusin Dec 1989 A
6341821 Rousseau Jan 2002 B1