U.S. patent number 3,881,772 [Application Number 05/403,013] was granted by the patent office on 1975-05-06 for chair control mechanism.
This patent grant is currently assigned to Stewart-Warner Corporation. Invention is credited to Harry L. Mohrman.
United States Patent |
3,881,772 |
Mohrman |
May 6, 1975 |
**Please see images for:
( Certificate of Correction ) ** |
CHAIR CONTROL MECHANISM
Abstract
A chair control mechanism having relatively tiltable first and
second frame members. A horizontal shaft extends through the frame
members for tiltable interconnecting the same. Spring means is
connected with the shaft and extends between the frame members for
resisting relative tilting movement between the frame members in
one direction.
Inventors: |
Mohrman; Harry L. (Weatogue,
CT) |
Assignee: |
Stewart-Warner Corporation
(Chicago, IL)
|
Family
ID: |
23594162 |
Appl.
No.: |
05/403,013 |
Filed: |
October 3, 1973 |
Current U.S.
Class: |
297/300.4;
297/361.1; 248/609; 297/303.3 |
Current CPC
Class: |
A47C
3/026 (20130101); A47C 7/443 (20130101); A47C
7/444 (20180801); A47C 7/441 (20130101); A47C
7/448 (20130101); A47C 7/445 (20130101) |
Current International
Class: |
A47C
3/02 (20060101); A47C 3/026 (20060101); A47c
003/00 () |
Field of
Search: |
;248/374,375
;297/296,298,300,304,305,306,361 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
|
869,337 |
|
Apr 1971 |
|
CA |
|
869,338 |
|
Apr 1971 |
|
CA |
|
Primary Examiner: Frazier; Roy D.
Assistant Examiner: Lyddane; William E.
Attorney, Agent or Firm: Douvas; Augustus G.
Claims
The invention claimed is:
1. A chair control mechanism comprising: a first frame member
extending forwardly and rearwardly and having a pair of parallel
elongated vertical side wall portions, laterally outwardly
extending upper flange portions integral with said side wall
portions for attachment to the underside of a chair seat, and a
lower transverse web portion interconnecting only the forward
sections of said side wall portions and forming a U-shaped frame
member, said web portion defining a laterally extending abutment; a
second frame member; a transverse shaft extending through said
second frame member and said side wall portions of said first frame
member rearwardly of said web portion of the latter whereby to
tiltably position said first and second frame members, said second
frame member has at least one pair of vertically spaced, forwardly
projecting are segments engageable with opposed sides of said web
portion abutment of said first frame member for limiting relative
tilting movement between said first and second frame members in
both directions, the axis of said transverse shaft lying
substantially in the same horizontal plane as said web portion, and
spring means connected with said transverse shaft and extending
between said first and second frame members in one direction.
2. The chair control mechanism of claim 1 wherein said spring means
includes an inner sleeve member on said shaft and nonrotatably
secured in position relative to said first frame member, an outer
sleeve member radially spaced from said first sleeve member, a
resilient body member intermediate of and bonded to said inner and
outer sleeve members, a collar member secured to said outer sleeve
member and having an arm portion, and adjustable means carried by
said arm portion and engaged with said second frame member for
adjustably tensioning said resilient body member in torsion.
3. The chair control mechanism of claim 1 wherein said second frame
member has a transverse web portion and a transverse bar portion;
and including a chair back bracket one end of which is seated
between said web and bar portions of said second frame member, and
means for securing said chair back bracket to said web portion of
said second frame member.
4. The chair control mechanism of claim 1 wherein said second frame
member has an upstanding hemispheric portion with a slot therein;
and including a chair back support member, a transverse pin member
pivotally mounting said chair back support member to said second
frame member, and adjustable means extending through said slot and
said chair back support member for adjusting the angular position
of the latter relative to said second frame member.
5. The chair control mechanism of claim 1 wherein said shaft is
rectangular in cross section at least at its ends; wherein said
first frame member is provided with a pair of slots that
nonrotatably receive said ends of said shaft; and wherein said
spring means includes a sleeve member surrounding said shaft in
spaced relation thereto, a resilient body member intermediate of
and bonded to said shaft and said sleeve member, a collar member on
said sleeve member and having an arm portion, means securing said
collar member to said sleeve member, and means carried by said arm
portion and engaged with said second frame member for adjustably
tensioning said resilient body member in torsion.
6. The chair control mechanism of claim 5 wherein said means
securing said collar member to said sleeve member comprises a roll
pin.
7. The chair control mechanism of claim 5 wherein three sides of
each of said pair of slots conform to three sides of said ends of
said shaft, and said first frame member is deformed at the end of
each of said pair of slots to maintain said shaft in said
slots.
8. The chair control mechanism of claim 5 wherein said ends of said
shaft are notched to define shoulders that engage said side wall
portions of said first frame member for locating said shaft
endwise.
9. The chair control mechanism of claim 1 wherein said spring means
includes a bearing plate, a helical coil spring disposed about said
shaft and having first extension means engaged with said bearing
plate and second extension means engaged with said first frame
member, and adjustable means carried by said bearing plate and
engaged with said second frame member for adjustably tensioning
said coil spring.
10. The chair control mechanism of claim 9 wherein said coil spring
comprises two coil sections with an intermediate loop extension
that defines said first extension means and with a pair of free end
extensions that define said second extension means.
11. The chair control mechanism of claim 1 wherein said spring
means includes a leaf spring having first and second arm portions
with said first arm portion engaged with said first frame member
and having an intermediate portion engaged with said shaft, and
adjustable means extending between said second arm portion of said
leaf spring and said second frame member for adjustably tensioning
said leaf spring.
12. A chair control mechanism as defined in claim 1, including a
passageway in said web portion for receiving either a post support
member or a spring tensioning member.
13. The chair control mechanism of claim 12 wherein said web
portion abutment has opposed sides engageable with said spaced arm
segments for limiting relative tilting movement between said first
and second frame members in both directions.
14. The chair control mechanism of claim 12 wherein said spring
means includes a first sleeve member on said shaft and nonrotatably
secured in position relative to said first frame member, a second
sleeve member radially spaced from said first sleeve member, a
resilient body member intermediate of and bonded to said first and
second sleeve members, and a a collar member secured to an second
sleeve member and having an arm portion; and wherein an adjustable
spring tensioning member is carried by said arm portion and engaged
with said second frame member for adjustably tensioning said
resilient body member in torsion.
15. The chair control mechanism of claim 12 wherein said second
frame member has a transverse web portion and a transverse bar
portion; and including a chair back bracket one end of which is
seated between said web and bar portions of said second frame
member, and means for securing said chair back bracket to said web
portion of said second frame member.
16. The chair control mechanism of claim 12 wherein said second
frame member has an upstanding hemispheric portion with a slot
therein; and including a chair back support member, a transverse
pin member pivotally mounting said chair back support member to
said second frame member, and adjustable means extending through
said slot and said chair back support member for adjusting the
angular position of the latter relative to said second frame
member.
17. The chair control mechanism of claim 12 wherein said shaft is
rectangular in cross section at least at its ends; wherein said
first frame member is provided with a pair of slots that
nonrotatably receive said ends of said shaft; wherein said spring
means includes a sleeve member surrounding said shaft in spaced
relation thereto, a resilient body member intermediate of and
bonded to said shaft and said sleeve member, a collar member on
said sleeve member and having an arm portion, means securing said
collar member to said sleeve member; and wherein an adjustable
spring tensioning member is carried by said arm portion and engaged
with said second frame member for adjustably tensioning said
resilient body member in torsion.
18. The chair control mechanism of claim 17 wherein said means
securing said collar member to said sleeve member comprises a roll
pin.
19. The chair control mechanism of claim 17 wherein three sides of
each of said pair of slots conform to three sides of said ends of
said shaft, and said first member is deformed at the end of each of
said pair of slots to maintain said shaft in said slots.
20. The chair control mechanism of claim 17 wherein said ends of
said shaft are notched to define shoulders that engage said first
frame member for locating said shaft endwise.
21. The chair control mechanism of claim 12 wherein said spring
means includes a bearing plate, and a helical coil spring disposed
about said shaft and having first extension means engaged with said
bearing plate and second extension means engaged with said first
frame member; and wherein said adjustable spring tensioning member
is carried by said bearing plate and engaged with said second frame
member for adjustably tensioning said coil spring.
22. The chair control mechanism of claim 21 wherein said coil
spring comprises two coil sections with an intermediate loop
extension that defines said first extension means and with a pair
of free end extensions that define said second extension means.
23. The chair control mechanism of claim 12 wherein said spring
means includes a leaf spring having first and second ends with said
first end engaged with said first frame member and having an
intermediate portion engaged with said shaft and wherein an
adjustable spring tensioning member is engaged with said leaf
spring adjacent said second end and with said second frame member
for adjustably tensioning said leaf spring.
Description
BACKGROUND OF THE INVENTION
The present invention relates to chair control mechanisms of the
type having two relatively tiltable frame members for supporting a
tiltable chair back assembly relative to a fixed chair seat as in a
stenographer's chair, or for supporting a tiltable chair seat and
back assembly relative to a fixed base as in an office chair.
Heretofore, a chair control mechanism for a stenographer's chair
has been entirely different in construction than a chair control
mechanism for an office chair. Moreover, a chair control mechanism
embodying one form of tilt resisting spring means has been entirely
different in construction than chair control mechanisms embodying
other forms of tilt resisting spring means. As a consequence, the
fabrication, assembly and inventory costs of prior art chair
control mechanisms have remained relatively high.
SUMMARY OF THE INVENTION
The present invention is concerned with the provision of a "family"
of various embodiments of low profile chair control mechanisms
utilizing common basic parts. Each embodiment comprises a first
frame member for attachment to the underside of a chair seat, a
second frame member tiltably supported by, or tiltably supporting,
the first frame member through a transverse shaft, and tilt
resisting spring means.
Each form of the first frame member can be fabricated from a common
basic stamping which is adapted for use with either a
stenographer's chair or an office chair, and which is adapted for
use with any one of several different types of tilt resisting
spring means. Likewise, a number of forms of the second frame
member can be each fabricated from a common basic stamping. By
utilizing such common basic parts in the series of chair control
mechanisms of the present invention, tooling, fabrication, assembly
and inventory costs are minimized.
More particularly, the basic stamping for each form of the first
frame member includes a forward web portion in which a passageway
is provided. The passageway serves to receive either a conventional
post support member or a spring tensioning member associated with
the tilt resisting spring means. Also, each form of the second
frame member includes a pair of spaced arm segments. When the first
and second frame members are in assembled relation, the transverse
shaft tiltably interconnecting the frame members is arranged
rearwardly of the web portion, and the arm segments are engageable
with the web portion for limiting relative tilting movement in both
directions. By reason of the aforesaid relationships, the series of
chair control mechanisms of the present invention are compact and
efficient.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a stenographer's chair
incorporating one embodiment of chair control mechanism of the
present invention;
FIG. 2 is a side elevational view, on an enlarged scale, of the
chair control mechanism of FIG. 1;
FIG. 3 is a view taken substantially along the line 3--3 in FIG. 2
looking in the direction indicated by the arrows;
FIG. 4 is a sectional view taken substantially along the line 4--4
in FIG. 3 looking in the direction indicated by the arrows;
FIG. 5 is a sectional view taken substantially along the line 5--5
in FIG. 3 looking in the direction indicated by the arrows;
FIG. 6 is a side elevational view of a stenographer's chair
incorporating another embodiment of chair control mechanism of the
present invention;
FIG. 7 is a side elevational view, on an enlarged scale, of the
chair control mechanism of FIG. 6;
FIG. 8 is a view taken substantially along the line 8--8 in FIG. 7
looking in the direction indicated by the arrows;
FIG. 9 is a sectional view taken substantially along the line 9--9
in FIG. 8 looking in the direction indicated by the arrows;
FIG. 10 is a sectional view taken substantially along the line
10--10 in FIG. 8 looking in the direction indicated by the
arrows;
FIG. 11 is a side elevational view of a stenographer's chair
incorporating another embodiment of chair control mechanism of the
present invention;
FIG. 12 is a partial plan view, on an enlarged scale, of the chair
control mechanism of FIG. 11;
FIG. 13 is a sectional view taken substantially along the line
13--13 in FIG. 12 looking in the direction indicated by the
arrows;
FIG. 14 is a sectional view taken substantially along the line
14--14 in FIG. 13 looking in the direction indicated by the
arrows;
FIG. 15 is a side elevational view of a stenographer's chair
incorporating another embodiment of chair control mechanism of the
present invention;
FIG. 16 is a side elevational view, on an enlarged scale, of the
chair control mechanism of FIG. 15;
FIG. 17 is a view taken substantially along the line 17--17 in FIG.
16 looking in the direction indicated by the arrows;
FIG. 18 is a sectional view taken substantially along the line
18--18 in FIG. 17 looking in the direction indicated by the
arrows;
FIG. 19 is a sectional view taken substantially along the line
19--19 of FIG. 17 looking in the direction indicated by the
arrows;
FIG. 20 is a side elevational view of a stenographer's chair
incorporating a further embodiment of chair control mechanism of
the present invention;
FIG. 21 is a side elevational view, on an enlarged scale, of the
chair control mechanism of FIG. 20;
FIG. 22 is a view taken substantially along the line 22--22 of FIG.
21 looking in the direction indicated by the arrows;
FIG. 23 is a sectional view taken substantially along the line
23--23 of FIG. 22 looking in the direction indicated by the
arrows;
FIG. 24 is a sectional view taken substantially along the line
24--24 of FIG. 22 looking in the direction indicated by the
arrows;
FIG. 25 is a side elevational view of an office chair incorporating
a further embodiment of chair control mechanism of the present
invention;
FIG. 26 is a side elevational view, on an enlarged scale, of the
chair control mechanism of FIG. 25;
FIG. 27 is a view taken substantially along the line 27--27 of FIG.
26 looking in the direction indicated by the arrows;
FIG. 28 is a sectional view taken substantially along the line
28--28 of FIG. 27 looking in the direction indicated by the arrows;
and
FIG. 29 is a sectional view taken substantially along the line
29--29 of FIG. 28 looking in the direction indicated by the
arrows.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, there is illustrated a stenographer's
chair 10 incorporating one embodiment of chair control mechanism 12
of the present invention. The chair 10 includes a base frame 14
with supporting legs 16, a vertically adjustable threaded post 18,
a fixed chair seat 20, and a pivotal or tiltable chair back bracket
22 carrying a chair back 24.
As shown in FIGS. 2-5, the chair control mechanism 12 comprises a
first frame member or chair control seat support 26 which is
fabricated as an integral metal stamping and which extends
forwardly and rearwardly of the chair seat 20 in operative
position. The first frame member 26 has a pair of parallel
elongated vertical side wall portions 28, laterally outwardly
extending upper flange portions 30 which are suitably attached to
the underside of the chair seat 20, and a lower transverse web
portion or engagement means 32 interconnecting the forward sections
of the side wall portions 28. The side wall portions 28 are
provided with aligned openings 34. The web portion 32 is formed
with an upwardly offset central section 36 through which a screw
post bushing placement opening or passageway 38 is provided.
Secured in the passageway 38 is a tubular post support member or
screw post bushing 40 which receives and is seated upon the upper
end of the threaded post 18.
The chair control mechanism 12 also comprises a second frame member
or chair control body 42 which extends parallel to the first frame
member 26. The second frame member 42 has a pair of parallel
elongated vertical side wall portions 44, and an upper transverse
web portion 46. The side wall portions 44 are formed with
vertically spaced forwardly projecting arm means or segments 48 and
50, aligned slots 52 below the web portion 46, intermediate aligned
openings 54, and rear inturned wings 55; while the web portion 46
is formed with an opening 56. A transverse support bar 58 is
secured at its ends in the slots 52.
A transverse shaft or axle 60 in the form of a bolt extends through
the side wall openings 34 of the first frame member 26 and the side
wall openings 54 of the second frame member 42 whereby to pivotally
or tiltably position the first and second frame members 26 and 42.
The shaft or bolt 60 is secured in position by means of a nut 62.
With the first and second frame members 26 and 42 in assembled
relation, the spaced arm segments 48 and 50 are engageable with the
opposed sides of the web portion 32 for limiting tilting movement
of the second frame member 42 relative to the first frame member 26
in both directions. To accommodate the described tilt limiting
means and to minimize the overall height of the chair control
mechanism 12, the transverse shaft 60 is offset rearwardly of the
web portion 32.
Spring means 64 is connected with the transverse shaft 60 and
extends between the first and second frame members 26 and 42 for
resisting tilting movement of the second frame member 42 relative
to the first frame member 26 in one direction. The spring means 64
includes a torsion elastomer unit 66 comprised of an inner sleeve
member 68 on the shaft 60, an outer sleeve member 70 radially
spaced from the inner sleeve member 68, and a resilient body member
72 intermediate of and bonded chemically to the inner and
mechanically to the outer sleeve members 68 and 70 respectively.
The ends of the inner sleeve member 68 are formed with notches 74,
and, during assembly of the chair control mechanism 12, the side
wall portions 28 are deformed inwardly adjacent the openings 34 to
define ribs 76 that project into the notches 74 whereby the inner
sleeve member 68 is nonrotatably secured in position relative to
the first frame member 26. Disposed about the torsion elastomer
unit 66 is a collar member 78 having a rearwardly extending arm
portion 80. The collar member 78 is secured to the outer sleeve
member 70 by means of a flared roll pin 82 disposed through a
transverse strap or positioner 84, threaded through the collar 78
and engaged with the sleeve 70. Adjustable means 86 is carried by
the arm portion 80 for adjustably tensioning the resilient body
member 72 in torsion. The adjustable means 86 comprises a
tensioning screw 88 threaded through the arm portion 80, engaged
with the transverse bar 58 of the second frame member 42 and locked
in position by a nut 90.
As shown in FIG. 4, the second frame member 42 serves to support
the chair back bracket 22. Specifically, the lower end of the
bracket 22 is seated between the web and bar portions 46 and 58,
and is secured to the web portion 46 by means of a screw 92 and a
nut member 94. The transverse bar 58 and side wall wings 55 serve
to retain the bracket 22 in position in the event the screw 92
works loose or the bracket 22 breaks away from the screw 92. The
bar 58 also provides a working surface for the tensioning screw 88.
As shown in FIG. 2, the second frame member 42 and the chair back
bracket 22 are tiltable between the solid and dotted line
positions.
Referring now to FIG. 6, there is illustrated a stenographer's
chair 10a incorporating another embodiment of chair control
mechanism 12a of the present invention. The chair 10a includes a
base frame 14a with supporting legs 16a, a vertically adjustable
threaded post 18a, a fixed chair seat 20a, and a pivotal or
tiltable chair back bracket 22a carrying a chair back 24a.
As shown in FIGS. 7-10, the chair control mechanism 12a comprises a
first frame member 26a which is fabricated as an integral metal
stamping and which extends forwardly and rearwardly of the chair
seat 20a in operative position. The first frame member 26a has a
pair of parallel elongated vertical side wall portions 28a,
laterally outwardly extending upper flange portions 30a which are
suitably attached to the underside of the chair seat 20a, and a
lower transverse web portion or engagement means 32a
interconnecting the forward sections of the side wall portions 28a.
The side wall portions 28a are provided with aligned openings 34a.
The web portion 32a is formed with an upwardly offset central
section 36a through which a passageway 38a is provided. Secured in
the passageway 38a is a tubular post support member 40a which
receives and is seated upon the upper end of the threaded post
18a.
The chair control mechanism 12a also comprises a second frame
member 42a which extends parallel to the first frame member 26a.
The second frame member 42a has a pair of parallel elongated
vertical side wall portions 44a, and an upper transverse web
portion 46a. The side wall portions 44a are formed with vertically
spaced forwardly projecting arm means or segments 48a and 50a,
aligned slots 52a below the web portion 46a, and intermediate
aligned openings 54a; while the web portion 46a is formed with an
opening 56a. A transverse support bar 58a is secured at its ends in
the slots 52a.
A transverse shaft 60a in the form of a bolt extends through the
side wall openings 34a of the first frame member 26a and the side
wall openings 54a of the second frame member 42a whereby to
pivotally or tiltably interconnect the first and second frame
members 26a and 42a. Arranged intermediate of the first and second
frame members 26a and 42a are an adaptor sleeve 96 and spacer rings
98. The shaft or bolt 60a is secured in position by means of a nut
62a. With the first and second frame members 26a and 42a in
assembled relation, the spaced arm segments 48a and 50a are
engageable with the opposed sides of the web portion 32a for
limiting tilting movement of the second frame member 42a relative
to the first frame member 26a in both directions. To accommodate
the described tilt limiting means and to minimize the overall
height of the chair control mechanism 12a, the transverse shaft 60a
is offset rearwardly of the web portion 32a.
Spring means 100 torsionally encircles the transverse shaft 60a and
extends between the first and second frame members 26a and 42a for
resisting tilting movement of the second frame member 42a relative
to the first frame member 26a in one direction. The spring means
100 includes a double wound helical coil torsion spring 102
comprised of two coil sections 104 and 106 with an intermediate
loop extension or first extension means 108 and with a pair of free
end extensions or second extension means 110. The loop extension
108 is engaged with a bearing plate 112, while the free end
extensions 110 are engaged under the web portion 32a of the first
frame member 26a. Adjustable means 114 is carried by the bearing
plate 112 for adjustably tensioning the coil spring 102. The
adjustable means 114 comprises a tensioning screw 116 threaded
through the bearing plate 112 and engaged with the transverse bar
58a of the second frame member 42a.
As shown in FIG. 9, the second frame member 42a serves to support
the chair back bracket 22a. Specifically, the lower end of the
bracket 22a is seated between the web and bar portions 46a and 58a,
and is secured to the web portion 46a by means of a screw 92a and a
nut member 94a. As shown in FIG. 7, the second frame member 42a and
the chair back bracket 22a are tiltable between the solid and
dotted line positions.
Referring now to FIG. 11, there is illustrated a stenographer's
chair 10b incorporating another embodiment of chair control
mechanism 12b of the present invention. The chair 10b includes a
base frame 14b with supporting legs 16b, a vertically adjustable
threaded post 18b, a fixed chair seat 20b, and a pivotal or
tiltable chair back bracket 22b carrying a chair back 24b.
As shown in FIGS. 12-14, the chair control mechanism 12b comprises
a first frame 26b which is fabricated as an integral metal stamping
and which extends forwardly and rearwardly of the chair seat 20b in
operative position. The first frame member 26b has a pair of
parallel elongated vertical side wall portions 28b, laterally
outwardly extending upper flange portions 30b which are suitably
attached to the underside of the chair seat 20b, and a lower
transverse web portion or engagement means 32b interconnecting the
forward sections of the side wall portions 28b. The side wall
portions 28b are provided with aligned openings 34b. The web
portion 32b is formed with an upwardly offset central section 36b
through which a passageway 38b is provided. Secured in the
passageway 38b is a tubular post support member 40b which receives
and is seated upon the upper end of the threaded post 18b.
The chair control mechanism 12b also comprises a second frame
member 42b which extends parallel to the first frame member 26b.
The second frame member 42b has a pair of parallel elongated
vertical side wall portions 44b, and an upper transverse web
portion 46b. The side wall portions 44b are formed with vertically
spaced forwardly projecting arm means or segments 48b and 50b, and
intermediate aligned openings 54b; while the web portion 46b is
formed with an opening 56b.
A transverse shaft 60b in the form of a bolt extends through the
side wall openings 34b of the first frame member 26b and the side
wall openings 54b of the second frame member 42b whereby to
pivotally or tiltably interconnect the first and second frame
members 26b and 42b. The shaft or bolt 60b is secured in position
by means of a nut 62b. With the first and second frame members 26b
and 42b in assembled relation, the spaced arm segments 48b and 50b
are engageable with the opposed sides of the web portion 32b for
limiting tilting movement of the second frame member 42b relative
to the first frame member 26b in both directions. To accommodate
the described tilt limiting means and to minimize the overall
height of the chair control mechanism 12b, the transverse shaft 60b
is offset rearwardly of the web portion 32b.
Spring means 118 is connected with the transverse shaft 60b and
extends between the first and second frame members 26b and 42b for
resisting tilting movement of the second frame member 42b relative
to the first frame member 26b in one direction. The spring means
118 includes a leaf spring 120 having a first arm portion 122, and
a second arm portion 124 and an intermediate arcuate portion 126.
The first arm portion 122 is engaged under the web portion 32b of
the first frame member 26b, while the intermediate portion 126 is
engaged with the shaft 60b. Adjustable means 128 extends between
the second arm portion 124 and the second frame member 42b for
adjustably tensioning the leaf spring 120. The adjustable means 128
comprises a tensioning screw 130 which is threaded through a nut
132 secured to the leaf spring 120 and which is engaged with the
lower end of the chair back bracket 22b that is secured to the web
portion 46b of the second frame member 42b by means of a screw 92b
and a nut member 94b. The second frame member 42b and the chair
back bracket 22b are tiltable from the position shown in FIG. 13
clockwise toward a position where the lower arm segments 50b
engages the web portion 32b of the first frame member 26b.
Referring now to FIG. 15, there is illustrated a stenographer's
chair 10c incorporating another embodiment of chair control
mechanism 12c of the present invention. The chair 10c includes a
base frame 14c with supporting legs 16c, a vertically adjustable
threaded post 18c, a fixed chair seat 20c, and a pivotal or
tiltable chair back bracket 22c carrying a chair back 24c.
As shown in FIGS. 16-19, the chair control mechanism 12c comprises
a first frame member 26c which is fabricated as an integral metal
stamping and which extends forwardly and rearwardly of the chair
seat 20c in operative position. The first frame member 26c has a
pair of parallel elongated vertical side wall portions 28c,
laterally outwardly extending upper flange portions 30c which are
suitably attached to the underside of the chair seat 20c, and a
lower transverse web portion or engagement means 32c
interconnecting the forward sections of the side wall portions 28c.
The sidewall portions 28c are formed with aligned slots 134 and ear
portions 136. The web portion 32c is formed with an upwardly offset
central section 36c through which a passageway 38c is provided.
Secured in the passgeway 38c is a tubular post support member 40c
which receives and is seated upon the upper end of the threaded
post 18c.
The chair control mechanism 12c also comprises a second frame
member 42c which extends parallel to the first frame member 26c.
The second frame member 42c has a pair of parallel elongated
vertical side wall portions 44c, and an upper transverse web
portion 46c. The side wall portions 44c are formed with vertically
spaced forwardly projecting arm means or segments 48c and 50c,
aligned slots 52c below the web portion 46c, and intermediate
aligned openings 54c; while the web portion 46c is formed with an
opening 56c. A transverse support bar 48c is secured at its ends in
the slots 52c.
A transverse shaft 138, which is rectangular in cross section at
least at its ends, extends through the side wall slots 134 of the
first frame member 26c and the side wall openings 54c of the second
frame member 42c whereby to pivotally or tiltably interconnect the
first and second frame members 26c and 42c. Three sides of the side
wall slots 134 conform to three sides of the ends of the shaft 138;
hence, the slots 134 nonrotatably receive the ends of the shaft
138. Prior to assembly, the ear portions 136 are disposed in a
spread-apart position to permit the shaft 138 to be moved into the
slots 134. After the shaft 138 has been placed in the slots 134,
the ear portions 136 are deformed or forced together to maintain
the shaft 138 in the slots 134. Also, the ends of the shaft 138 are
notched to defined shoulders 140 that engage the side wall portions
28c of the first frame member 26c for locating the shaft 138
endwise.
With the first and second frame members 26c and 42c in assembled
relation, the spaced arm segments 48c and 50c are engageable with
the opposed sides of the web portion 32c for limiting tilting
movement of the second frame member 42c relative to the first frame
member 26c in both directions. To accommodate the described tilt
limiting means and to minimize the overall height of the chair
control mechanism 12c, the transverse shaft 138 is offset
rearwardly of the web portion 32c.
Spring means 142 is connected with the transverse shaft 138 and
extends between the first and second frame members 26c and 42c for
resisting tilting movement of the second frame member 42c relative
to the first frame member 26c in one direction. The spring means
142 includes a torsion elastomer unit 144 comprised of a sleeve
member 146 radially spaced from the shaft 138, and a resilient body
member 148 intermediate of and bonded to the shaft 138 and sleeve
member 146. Disposed about the torsion spring unit 144 is a collar
member 78c having a rearwardly extending arm portion 80c. The
collar member 78c is secured to the sleeve member 146 by means of a
flared roll pin 150 disposed through a transverse strap or
positioner 84c, threaded through the collar 78c and engaged in the
sleeve 146. Adjustable means 86c is carried by the arm portion 80c
for adjustably tensioning the resilient body member 148 in torsion.
The adjustable means 86c comprises a tensioning screw 88c threaded
through the arm portion 80 c, engaged with the transverse bar 58c
and locked in position by a nut 90c. The lower end of the chair
back bracket 22c is seated between the web and the bar portions 46c
and 58c, and is secured to the web portion 46c of the second frame
member 42c by means of a screw 92c and a nut member 94c. As shown
in FIG. 16, the second frame member 42c and the chair back bracket
22c are tiltable between the solid and dotted line positions.
Referring now to FIG. 20, there is illustrated a stenographer's
chair 10d incorporating a further embodiment of chair control
mechanism 12d of the present invention. The chair 10d includes a
base frame 14d with supporting legs 16d, a vertically adjustable
threaded post 18d, a fixed chair seat 30d, and a pivotal or
tiltable chair back bracket 22d carrying a chair back 24d.
As shown in FIGS. 21-24, the chair control mechanism 12d comprises
a first frame member 26d which is fabricated as an integral metal
stamping and which extends forwardly and rearwardly of the chair
seat 20d in operative position. The first frame member 26d has a
pair of parallel elongated vertical wall portions 28d, laterally
outwardly extending upper flange portions 30d which are suitably
attached to the underside of the chair seat 20d, and a lower
transverse web portion or engagement means 32d interconnecting the
forward sections of the side wall portions 28d. The side wall
portions 28d are provided with aligned openings 34d. The web 32d is
formed with an upwardly offset central section 36d through which a
passageway 38d is provided. Secured in the passageway 38d is a
tubular post support member 40d which receives and is seated upon
the upper end of the threaded post 18d.
The chair control mechanism 12 d also comprises a second frame
member 42d which extends parallel to the first frame member 26d.
The second frame member 42d has a pair of parallel elongated
vertical side wall portions 44d, and an upper transverse web
portion 46d. The side wall portions 44d are formed with vertically
spaced forwardly projecting arm means or segments 48d and 50d, and
intermediate aligned openings 54d; while the web portion 46d is
formed with an upstanding hemispheric portion 152 having a slot 154
therein.
A transverse shaft 60d in the form of a bolt extends through the
side wall opeings 34d of the first frame member 26d and the side
wall openings 54d of the second frame member 42d whereby to
pivotally or tiltably interconnect the first and second frame
members 26d and 42d. The shaft or bolt 60d is secured in position
by means of a nut 62d. With the first and second frame members 26d
and 42d in assembled relation, the spaced arms segments 48d and 50d
are engageable with the opposed sides of the web portion 32d for
limiting tilting movement of the second frame member 42d relative
to the first frame member 26d in both directions. To accommodate
the described tilt limiting means and to minimize the overall
height of the chair control mechanism 12d, the transverse shaft 60d
is offset rearwardly of the web portion 32d.
Spring means 64d is connected with the transverse shaft 60d and
extends between the first and second frame members 26d and 42d for
resisting tilting movement of the second frame member 42d relative
to the first frame member 26d in one direction. The spring means
64d includes a torsion elastomer unit 66d comprised of an inner
sleeve member 68d on the shaft 60d, an outer sleeve member 70d
radially spaced from the inner sleeve member 68d, and a resilient
body member 72d intermediate of and bonded chemically to the inner
and mechanically to the outer sleeve members 68d and 70d
respectively. The ends of the inner sleeve member 68d are formed
with notches 74d, and, during assembly of the chair control
mechanism 12d, the side wall portions 28d are deformed inwardly
adjacent the openings 34d to define ribs 76d that project into the
notches 74d whereby the inner sleeve member 68d is nonrotatably
secured in position relative to the first frame member 26d.
Disposed about the torsion elastomer unit 66d is a collar member
78d having a rearwardly extending arm portion 80d. The collar
member 78d is secured to the outer sleeve member 70d by means of a
screw 82d disposed through a transverse strap or positioner 84d,
threaded through the collar 78d and engaged in the sleeve 70d.
Adjustable means 86d is carried by the arm portion 80d for
adjustably tensioning the resilient body member 72d in torsion. The
adjustable means 86d comprises a tensioning screw 88d threaded
through the arm portion 80d, engaged with the web portion 46d of
the second frame member 42d and locked in position by a nut
90d.
Mounted adjacent the rear end of the second frame member 42d is a
generally L-shaped chair back support member 156 to which is
connected the lower end of the chair back bracket 22d. The chair
back support member 156 is pivotally mounted between the side wall
portions 44d by means of a transverse spring pin member 158.
Adjustable means 160 extends through the slot 154 and the chair
back support member 156 for adjusting the angular position of the
latter relative to the second frame member 42d. The adjustable
means 160 comprises a bolt-like stem member 162 having an upper end
portion 164 that projects through the slot 154, an intermediate
portion 166 presenting an annular spherical surface 168 that
engages the underside of the hemispheric portion 152 at the sides
of the slot 154, and a lower threaded portion 170 threaded through
the chair back support member 156. The upper end portion 164 of the
member 162 is maintained within the slot 154 by a spring slip 172.
The second frame member 42d, the chair back support member 156 and
the chair back bracket 22d are tiltable from the position shown in
FIG. 21 clockwise toward a position where the lower arm segments
50d engage the web portion 32d of the first frame member 26d.
Referring now to FIG. 25, there is illustrated an office chair 174
incorporating a further embodiment of chair control mechanism 12e
of the present invention. The chair 174 includes a base frame 176
with supporting legs 178, a vertically adjustable threaded post
180, and a pivotal or tiltable chair seat 182 with a back 184 and
arms 186 fixed thereto.
As shown in FIGS. 26-29, the chair control mechanism 12e comprises
a first frame member 26e which is fabricated as an integral metal
stamping and which extends forwardly and rearwardly of the chair
seat 182 in operative position. The first frame member 26e has a
pair of parallel elongated vertical side wall portions 28e,
laterally outwardly extending upper flange portions 30e which are
suitably attached to the undeside of the chair seat 182, and a
lower transverse web portion or engagement means 32e
interconnecting the forward sections of the side wall portions 28e.
The sidewall portions 28e are formed with aligned openings 34e. The
web portion 32e is formed with an upwardly offset central section
36e through which a passageway 38e is provided.
The chair control mechanism 12e also comprises a second frame
member or chair control body 188 which extends parallel to the
first frame member 26e. The second frame member 188 has a pair of
parallel elongated vertical side wall portions 190, and a lower
transverse web portion 192. The side wall portions 190 are formed
with vertically spaced forwardly projecting arm means or segments
194 and 196, the upper arm segments 194 of which are notched at 198
and interconnected by a strap member 200. The side wall portions
190 are also formed with intermediate aligned openings 202; while
the web portion 192 is formed with a screw post bushing placement
opening 204. Secured in the web opening 204 is a tubular post
support member 40e which receives and is seated upon the upper end
of the threaded post 180.
A transverse shaft 60e in the form of a bolt extends through the
side wall openings 34e of the first frame member 26e and the side
wall openings 202 of the second frame member 188 whereby to
pivotally or tiltably interconnect the first and second frame
members 26e and 188. The shaft or bolt 60e is secured in position
by means of a nut 62e. With the first and second frame members 26e
iand 188 in assembled relation, the spaced arm segments 194 and 196
are engageable with the opposed sides of the web portion 192 for
limiting tilting movement of the first frame member 26e relative to
the second frame member 188 in both directions. To accommodate the
described tilt limiting means and to minimize the overall height of
the chair control mechanism 12e, the transverse shaft 60e is offset
rearwardly of the web portion 192.
Spring means 64e is connected with the transverse shaft 60e and
extends between the first and second frame members 26e and 188 for
resisting tilting movement of the first frame member 26e relative
to the second frame member 188 in one direction. The spring means
64e includes a torsion elastomer unit 66e comprised of an inner
sleeve member 68e on the shaft 60e, an outer sleeve member 70e
radially spaced from the inner sleeve member 68e, and a resilient
body member 72e intermediate of and bonded chemically to the inner
and mechanically to the outer sleeve members 68e and 70e
respectively. The ends of the inner sleeve member 68e are formed
with notches 74e, and, during assembly of the chair control
mechanism 12e, the side wall portions 190 are deformed inwardly
adjacent the openings 34e to define ribs 208 that project into the
notches 74e whereby the inner sleeve member 68e is nonrotatably
secured in position relative to the first frame member 26e.
Disposed about the torsion elastomer unit 66e is a collar member
78e having a forwardly extending arm portion 80e. The collar member
78e is secured to the outer sleeve member 70e by means of a flared
roll pin 82e threaded through the collar 78e and engaged in the
sleeve 70e. Adjustable means 86e is carried by the arm portion 80e
for adjustably tensioning the resilient body member 72e in torsion.
The adjustable means 86e comprises a spring tensioning member or
screw 88e threaded through the arm portion 80e, extending through
the web passageway 38e of the first frame member 26e, engaged with
the strap member 200 of the second frame member 188 and locked in
position by a nut 90e. The first frame member 26e (together with
the chair seat 182, back 184 and arms 186) is tiltable from the
solid line position shown in FIG. 26 clockwise through the dotted
line position toward a position where the web portion 32e engages
the upper arm segments 194.
As will be appreciated from a comparison of the chair control
mechanisms 12-12e disclosed herein: the first frame members 26-26e
can be fabricated from common basic stampings in which appropriate
openings and slots are thereafter selectively formed; the basic
stamping common to the first frame members 26-26e is adapted for
use with either a stenographer's chair (e.g., FIG. 1) or an office
chair (e.g., FIG. 25); the common web passageways 38-38e serve to
receive either a post support member (e.g. member 40, FIG. 4) or a
spring tensioning member (e.g., member 88e, FIG. 28); the second
frame members 42-42c can be fabricated from common basic stampings
in which appropriate openings and slots are thereafter selectively
formed; and the basic stampings common to the first and second
frame members 26-26e and 42-42c are adapted for use with any one of
several different forms of tilt resisting spring means.
While there has been shown and described preferred embodiments of
the present invention, it will be understood by those skilled in
the art that various modifications and rearrangements may be made
therein without departing from the spirit and scope of the
invention.
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