U.S. patent application number 12/108669 was filed with the patent office on 2009-10-29 for pivot assembly.
This patent application is currently assigned to LEGGETT & PLATT CANADA CO.. Invention is credited to ROBERT W. DOERNER, SHAFFEEK A. YUSUF.
Application Number | 20090267395 12/108669 |
Document ID | / |
Family ID | 41212298 |
Filed Date | 2009-10-29 |
United States Patent
Application |
20090267395 |
Kind Code |
A1 |
DOERNER; ROBERT W. ; et
al. |
October 29, 2009 |
PIVOT ASSEMBLY
Abstract
A pivot assembly has a pivot support member with a keyway. The
keyway has two oppositely directed longer keyway wings extending
from a middle section and the middle section has two oppositely
directed shorter keyway wings extending in a direction transverse
to that of the longer keyway wings. The shorter keyway wings have
convexly radiused ends. The pivot assembly also has a pivot with an
attachment portion and a key projecting rearwardly from the
attachment portion. The key has a rearward section with oppositely
directed longer key wings which are longer than the shorter keyway
wings but sufficiently short to allow the longer key wings to pass
through the keyway. The key also has a middle section between the
rearward section and the attachment portion. The middle section has
oppositely directed shorter key wings with convexly radiused ends.
The shorter key wings extend in a direction aligned with that of
the longer key wings. The shorter key wings have a length
substantially matching that of a length of the shorter keyway
wings. The radiused end of each shorter key wing has a radius
substantially matching a radius of a radiused end of each of the
shorter keyway wings such that the shorter key wings fit with a
close tolerance between ends of the keyway shorter wings.
Inventors: |
DOERNER; ROBERT W.;
(WATERLOO, CA) ; YUSUF; SHAFFEEK A.; (WATERLOO,
CA) |
Correspondence
Address: |
SHOOK, HARDY & BACON LLP;INTELLECTUAL PROPERTY DEPARTMENT
2555 GRAND BLVD
KANSAS CITY
MO
64108-2613
US
|
Assignee: |
LEGGETT & PLATT CANADA
CO.
WATERLOO
CA
|
Family ID: |
41212298 |
Appl. No.: |
12/108669 |
Filed: |
April 24, 2008 |
Current U.S.
Class: |
297/310 ;
16/110.1 |
Current CPC
Class: |
Y10T 16/44 20150115;
A47C 1/023 20130101 |
Class at
Publication: |
297/310 ;
16/110.1 |
International
Class: |
A47C 7/00 20060101
A47C007/00 |
Claims
1. A pivot assembly comprising: a pivot support member having a
keyway, said keyway having two oppositely directed longer keyway
wings extending from a middle section, said middle section having
two oppositely directed shorter keyway wings extending in a
direction transverse to that of said longer keyway wings, said
shorter keyway wings having convexly radiused ends; and a pivot
having an attachment portion and a key projecting rearwardly from
said attachment portion, said key having a rearward section with
oppositely directed longer key wings which are longer than said
shorter keyway wings but sufficiently short to allow said longer
key wings to pass through said keyway and a middle section between
said rearward section and said attachment portion, said middle
section having oppositely directed shorter key wings having
convexly radiused ends, said shorter key wings extending in a
direction aligned with that of said longer key wings, said shorter
key wings having a length substantially matching that of a length
of said shorter keyway wings and each shorter key wing radiused end
having a radius substantially matching a radius of a radiused end
of each of said shorter keyway wings such that said shorter key
wings fit with a close tolerance between ends of said keyway
shorter wings.
2. The pivot assembly of claim 1 wherein said pivot support has a
thickness substantially matching a thickness of said middle section
of said pivot.
3. The pivot assembly of claim 2 wherein said pivot is of one piece
construction.
4. The pivot assembly of claim 3 wherein said pivot is fabricated
of plastic.
5. The pivot assembly of claim 1 wherein said attachment portion of
said pivot comprises a resilient C-shaped clip.
6. The pivot assembly of claim 5 wherein a central axis of said
C-shaped clip is aligned with a direction of said longer key
wings.
7. The pivot assembly of claim 1 wherein said longer key wings are
shorter than said longer keyway wings.
8. A pivot comprising: an attachment portion comprising a resilient
C-shaped clip; a key projecting rearwardly from said attachment
portion, said key having a rearward section with oppositely
directed longer key wings and a middle section between said
attachment portion and said rearward section, said middle section
having oppositely directed shorter key wings having convexly
radiused ends, said shorter key wings extending in a direction
aligned with that of said longer key wings, a central axis of said
C-shaped clip being aligned with a direction of said longer key
wings.
9. A chair control, comprising: a slide plate having a keyway, said
keyway having two oppositely directed longer keyway wings extending
from a middle section, said middle section having two oppositely
directed shorter keyway wings extending in a direction transverse
to that of said longer keyway wings, said shorter keyway wings
having convexly radiused ends; and a pivot having an attachment
portion and a key projecting rearwardly from said attachment
portion, said key having a rearward section with oppositely
directed longer key wings which are longer than said shorter keyway
wings but sufficiently short to allow said longer key wings to pass
through said keyway and a middle section between said rearward
section and said attachment portion, said middle section having
oppositely directed shorter key wings having convexly radiused
ends, said shorter key wings extending in a direction aligned with
that of said longer key wings, said shorter key wings having a
length substantially matching that of a length of said shorter
keyway wings and each shorter key wing radiused end having a radius
substantially matching a radius of a radiused end of each of said
shorter keyway wings, said shorter key wings fit between ends of
said keyway shorter wings.
10. The chair control of claim 9 wherein said slide plate has a
thickness substantially matching a thickness of said middle
section.
11. The chair control of claim 10, wherein said pivot is of one
piece construction.
12. The chair control of claim 11 wherein said pivot is fabricated
of plastic.
13. The chair control of claim 10 further comprising an arm
attached to said attachment portion of said pivot, said arm
terminating in a free end received in a slot of said slide plate
such that rotation of said arm at said pivot is limited.
14. The chair control of claim 13 wherein said attachment portion
of said pivot comprises a resilient C-shaped clip.
15. The chair control of claim 14 wherein a central axis of said
C-shaped clip is aligned with a direction of said longer key
wings.
16. The chair control of claim 9 wherein said longer key wings are
shorter than said longer keyway wings.
Description
BACKGROUND
[0001] This invention relates to a pivot assembly and to a chair
control incorporating a pivot assembly.
[0002] It is known to slidably mount a slide plate to the seat
plate of a chair control to allow the user to change the relative
position of a chair seat, which is attached to the slide plate, to
the seat plate. In a known arrangement, a U-shaped member is
pivotably mounted to either side of the slide plate with the free
ends of the U-shaped member received in racks which form part of
the seat plate. The U-shaped member is spring biased so that the
free ends are urged into the racks, thereby fixing the relative
position of the slide plate and seat plate. If the U-shaped member
is pivoted by a user against this spring pressure, the free ends
leave the racks, freeing the slide plate to slide with respect to
the seat plate. When a desired position is achieved, the U-shaped
member may be released whereupon the free ends of the member will
re-enter the racks and lock the slide plate in this new relative
position with respect to the seat plate.
[0003] The U-shaped member is pivotably mounted to the slide plate
by a pair of pivots, each of which has an attachment portion which
attaches to the U-shaped member. A pop rivet may be received
through a hole in a pivot and through the slide plate in order to
pivotably affix the pivot to the slide plate.
[0004] This invention seeks to provide an improved pivot
assembly.
SUMMARY OF INVENTION
[0005] In accordance with this invention, there is provided a pivot
assembly with a pivot support member having a keyway. The keyway
has two oppositely directed longer keyway wings extending from a
middle section and the middle section has two oppositely directed
shorter keyway wings extending in a direction transverse to that of
the longer keyway wings. The shorter keyway wings have convexly
radiused ends. The pivot assembly also has a pivot with an
attachment portion and a key projecting rearwardly from the
attachment portion. The key has a rearward section with oppositely
directed longer key wings which are longer than the shorter keyway
wings but sufficiently short to allow the longer key wings to pass
through the keyway. The key also has a middle section between the
rearward section and the attachment portion. The middle section has
oppositely directed shorter key wings with convexly radiused ends.
The shorter key wings extend in a direction aligned with that of
the longer key wings. The shorter key wings have a length
substantially matching that of a length of the shorter keyway
wings. The radiused end of each shorter key wing has a radius
substantially matching a radius of a radiused end of each of the
shorter keyway wings such that the shorter key wings fit with a
close tolerance between ends of the keyway shorter wings.
[0006] Other features and advantages will be apparent from the
following description in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] In the figures which illustrate an example embodiment of the
invention,
[0008] FIG. 1 is a perspective view of a chair control,
[0009] FIG. 2 is a partially assembled fragmentary perspective view
of the chair control of FIG. 1,
[0010] FIG. 2A is a fragmentary side view of a portion of FIG.
2,
[0011] FIG. 2B is a side view of a portion of FIG. 2,
[0012] FIG. 3A is a partially assembled fragmentary perspective
view of the chair control of FIG. 1,
[0013] FIG. 3B is a cross-sectional view along the lines 3B-3B of
FIG. 3,
[0014] FIG. 4A is a partially assembled fragmentary perspective
view of the chair control of FIG. 1,
[0015] FIG. 4B is a cross-sectional view along the lines 4B-4B of
FIG. 4,
[0016] FIG. 5 is a partially exploded perspective view of the chair
control of FIG. 1,
[0017] FIGS. 6A to 6E are schematic side views of the chair control
of FIG. 1 illustrating its operation.
DETAILED DESCRIPTION
[0018] Referring to FIGS. 1 and 6B, a chair control 10 has a slide
plate 12 with aligned longitudinal slots 14 receiving bolts 16 that
are screwed to a seat plate 20. This provides a sliding attachment
of the slide plate to the seat plate. A chair seat 18 (FIG. 6A) may
be attached to the slide plate. The seat plate 20 may be pivotably
mounted to the main frame 21 of the chair and the main frame 21 may
be supported on a gas cylinder (not shown) extending from a chair
base (not shown). A U-shaped member 22 is joined to the sides 24,
26 of the slide plate 12 by pivots 30. The U-shaped member has arms
68 terminating in inwardly turned free ends 32, each of which
extends through a slot 34 in the slide plate and terminates at a
rack 36 attached to the seat plate. The medial section of the
U-shaped member 22 forms a handle 38. A spring 40 coils around each
free end 32 and has its ends supported by catches 42 formed in the
slide plate. These springs bias the U-shaped member so that the
free ends 32 are urged into racks 36.
[0019] With reference to FIGS. 2 and 2A, the slide plate 12 has a
keyway 50 formed in each of its sides 24, 26. The keyway has two
oppositely directed longer keyway wings 52a, 52b extending from a
middle section formed by two oppositely directed shorter keyway
wings 54a, 54b. As is apparent from the figures, the shorter keyway
wings extend in a direction transverse to that of the longer keyway
wings. The shorter keyway wings 54a, 54b have radiused ends 56a,
56b.
[0020] Referencing FIGS. 2 and 2B, each pivot 30 has an attachment
portion 58 with a key 60 projecting rearwardly from the attachment
portion. The key has a rearward section, R, with oppositely
directed longer key wings 62a, 62b. The key also has a middle
section, M, between the rearward section and the attachment
portion. The middle section has a thickness slightly greater than
that of the thickness of the slide plate 12. The middle section has
oppositely directed shorter key wings 64a, 64b. The shorter key
wings 64a, 64b extend in a direction aligned with that of the
longer key wings 62a, 62b. The longer key wings 62a, 62b are longer
than the shorter keyway wings 54a, 54b and shorter than the longer
keyway wings 52a, 52b. The shorter key wings 64a, 64b have a length
substantially matching that of a length of the shorter keyway wings
54a, 54b and each shorter key wing has a radiused end 66a, 66b with
a radius substantially matching a radius of the radiused end of
each of said shorter keyway wings 54a, 54b.
[0021] The attachment portion 58 of each pivot 30 is C-shaped with
the central axis of the C-shape aligned with the direction of the
longer key wings 62a, 62b. An arm 68 of the U-shaped member 22 may
snap into the attachment section.
[0022] With reference to FIG. 2, the pivot 30 may be oriented so
that the longer key wings 62a, 62b are aligned with the longer
keyway wings 52a, 52b and the longer key wings 62a, 62b may then be
passed through keyway 50 as shown in FIGS. 3A and 3B until areas of
the rearward surface of the attachment portion 58 that extend
outside the periphery of the keyway abut the slide plate 12. In
this position, the longer key wings 62a, 62b are located behind the
back face of the side of the slide plate. Next, as shown in FIGS.
4A and 4B, the pivot 30 may be turned 90.degree. so that the longer
key wings 62a, 62b are now aligned with the shorter keyway wings
54a, 54b. Thus, the side wall of the slide plate is sandwiched
between the longer key wings 62a, 62b of the pivot and the rear
surface of the attachment portion 58 of the pivot. Consequently,
the pivot is locked to the side wall. Further, the shorter key
wings 64a, 64b are now located in the keyway and are aligned with
the shorter keyway wings 54a, 54b with the radiused ends 66a, 66b
of these wings snugly fitted against the radiused ends 56a, 56b of
the shorter keyway wings 54a, 54b.
[0023] Pivot 30 may be pivoted through a range of angles (of about
+/-30.degree.) from its position as shown in FIG. 4A while an
arcuate segment of each of the shorter key wings 64a, 64b remains
snugly fitted against the radiused ends 56a, 56b of the shorter
keyway wings 54a, 54b and the slide plate side wall remains
sandwiched between the longer key wings 62a, 62b and the rear
surface of the attachment portion 58. Thus, within this range of
motion, the pivot will remain securely locked to the side wall.
[0024] Prior to attaching a pivot 30 to each of side wall 24 and 26
of the slide plate, each pivot may be snapped onto an arm 68 of the
U-shaped member 22 and a spring 40 may be run over each arm. As the
pivots are pivoted toward the position indicated by FIG. 4, the
free ends 32 of the U-shaped member may be deflected outwardly to
allow the U-shaped member to pivot until these ends 32 pop into the
slots 34 in the side walls of the slide plate. With the ends 32
within slots 34, the range of pivoting motion of the U-shaped
member is limited by the abutment of the ends 32 with the ends of
the slots 34. This range of motion is selected so that the pivots
remain securely locked to the side wall throughout this range of
motion. The ends of the springs may then be inserted into catches
42 to bias the ends 32 of the U-shaped member into the racks
attached to the seat plate 20. Lastly, as shown in FIG. 5, a cap 70
may be snap fit to each pivot 30.
[0025] The pivot is of one piece construction and manufactured from
a hard plastic.
[0026] Operation of the chair control 10 is illustrated in FIGS. 6A
to 6E. With the U-shaped member in a slide plate locking position
(FIG. 6A) whereat the free ends 32 of the U-shaped member are
received in the racks of the seat plate, a user may lift handle 38
(FIG. 6B). This rotates the U-shaped member against the urging of
the springs 40 so that the ends 32 of the U-shaped member leave the
racks and abut the lower end of the slots 34 (FIG. 6C). The slide
plate may then be slid to any desired position. Thereafter, the
handle 38 may be released so that the U-shaped member rotates back
to its slide plate locking position (FIGS. 6D and 6E). (In this
regard, the nose of each tooth of the racks may be radiused so that
if each end 32 hits a tooth, the slide plate would move slightly to
align each end 32 with a notch between rack teeth.)
[0027] The described pivot assembly avoids the need for a separate
fastener (such as a pop rivet) to hold the pivot to the slide
plate. This therefore simplifies manufacturing.
[0028] Of course the pivot could be constructed of metal rather
than plastic. The longer wings of the keyway and key of the pivot
need not have radiused ends but could, if desired, instead have
ends which are squared off. The attachment portion of the pivot
need not be a resilient clip but could instead be any other
suitable attachment device, such as a two-piece housing which is
held together with a snap fit or fasteners.
[0029] The described pivot assembly could be used in other pivoting
applications where the range of pivoting is limited. Further, in
applications where the pivot may be tilted when it is inserted into
the keyway, the longer key wings could be longer than the longer
keyway wings. (The limit to the length of the longer keyway wings
would be that where, after the upper longer key wing is inserted
through the keyway at a tilt angle and the pivot raised until its
middle section abuts the end of the upper longer keyway wing, there
is just enough space for the lower longer key wing to pass through
the lower longer keyway wing.)
[0030] Other modifications will be apparent to those skilled in the
art and, therefore, the invention is defined in the claims.
* * * * *