U.S. patent number 3,876,248 [Application Number 05/381,318] was granted by the patent office on 1975-04-08 for extendible and contractible seat position adjustor.
This patent grant is currently assigned to Rockwell International Corporation. Invention is credited to Donald O. Gillentine.
United States Patent |
3,876,248 |
Gillentine |
April 8, 1975 |
Extendible and contractible seat position adjustor
Abstract
A seat position adjustor comprising a selectively extendible and
contractible connecting link assembly adapted operatively to
interconnect a stationary horizontally disposed seat bench member
and a seat back member pivotally mounted relative to said bench
member and to locate the seat back in one of a plurality of
positions. The assembly includes a one piece, thin-walled, tubular
housing partially and slidably receiving a rod that is spring
biased toward an extended position out of the housing. Within the
housing and surrounding the rod are a plurality of pivotally
mounted locking plates spring biased into an angular orientation
relative to the rod to lock the rod against movement. Manually
operable cam means act on the locking plates to change and position
and allow freedom of rod movement. The link assembly is designed so
the thin-walled, tubular housing may be machined and shaped from
exterior of the housing prior to or during the final assembly of
the parts of the device to provide stop means and fulcrum means
within the housing.
Inventors: |
Gillentine; Donald O.
(Dansville, MI) |
Assignee: |
Rockwell International
Corporation (Pittsburgh, PA)
|
Family
ID: |
23504560 |
Appl.
No.: |
05/381,318 |
Filed: |
July 20, 1973 |
Current U.S.
Class: |
297/375 |
Current CPC
Class: |
A47C
1/027 (20130101) |
Current International
Class: |
A47C
1/022 (20060101); A47C 1/027 (20060101); A47c
001/027 () |
Field of
Search: |
;297/375,355,354
;248/410,403,355,356 ;188/322 ;16/49 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Zugel; Francis K.
Claims
I claim:
1. A selectively extendible and contractible connecting link
assembly for a reclining seat actuator comprising a thin-walled,
tubular housing defining a chamber retaining first plug means for
sealing one end of said housing, and retaining second plug means
having an aperture therethrough in the other end of said housing, a
rod extending through said aperture and partially slidably received
in said housing, said housing also having first stop means formed
on diametrically opposed portions by spacedly slotting and inwardly
deforming portions of said housing, first apertured barrier means
positioned against said first stop means, said rod extending
through said barrier means, radially extending flange means secured
to said rod within said chamber, a main operating coil spring
surrounding said rod within said chamber, one end of said spring
bearing on said first barrier means and the other end of said
spring bearing on said flange means thereby biasing said rod out of
said housing and said assembly towards its extended condition, a
plurality of junxtaposed centrally apertured lock plates within
said chamber, said rod extending through the apertures therein,
said lock plate apertures being larger than said rod whereby said
lock plates can be tilted relative to said rod, second stop means
formed by inwardly deforming a portion of said housing and
comprising a fixed fulcrum offset from the axis of said rod, in
contact with one of said lock plates and preventing movement of
said lock plates away from the end of said housing from which said
rod protrudes, a locking spring encircling said rod and compressed
between a second apertured barrier means positioned against said
first stop means opposite from said first apertured barrier means
and the side of lock plates remote from said second stop means,
said spring being operative to tilt said lock plates around said
fulcrum and lock said rod and said housing against contractible
movement, said lock plates being effective to brake but not lock
said rod against movement in an extensible direction, a cam member
rotatably supported in said housing for selective direct engagement
with said lock plates on the side of said lock opposite said
fulcrum, and actuating means for rotating said cam to move said
lock plates against the force of said locking spring until said
locking plates are substantially normal to the axis of said rod
whereby said rod may be freely moved in either direction.
2. The assembly of claim 1, wherein said actuating means comprises
a manually actuatable handle secured to said cam member.
3. The assembly of claim 1, wherein each of said apertured barriers
comprises a washer having an outside diameter slightly smaller than
the inside diameter of said tubular housing.
4. The assembly of claim 1, wherein said inwardly deformed portion
of second stop means is adjacent a transversely extending slot
formed through the wall of said housing.
5. A selectively extendible and contractible connecting link
assembly adapted to operatively interconnect a relatively
stationary horizontally disposed seat bench member and a seat back
member pivotally connected to the seat bench member and to locate
said back in one of a plurality of positions, said assembly
comprising a one piece thin-walled, tubular housing defining an
elongated chamber, first plug means sealing one end of said housing
and adapted to be operatively secured to one of said seat members,
second plug means having an aperture formed therethrough in the
other end of said housing, a rod extending through said aperture
and partially slidably received in said housing, the end of said
rod projecting from said housing adapted to be secured to the other
of said seat members, barrier means extending transversely across
said chamber at a point spaced from both ends of said housing, said
barrier means having a central aperture extending therethrough
through which said rod extends, said barrier means including a pair
of diametrically oppositely located housing portions, each of said
portions being bounded by a pair of transversely extending slots
formed through the wall of said housing and being deformed inwardly
into said chamber, a radially extending flange carried by said rod
for unitary movement therewith and located between said barrier and
said second plug means, a main operating spring surrounding said
rod and partially compressed between said flange and said barrier
means, said spring exerting a force biasing said rod out of said
housing and said assembly into an extended condition, a fixed
fulcrum rigid with said housing and located between said barrier
means and said first plug means and offset from the axis of said
rod, rockable locking means surrounding said rod between said
barrier means and said fulcrum, bearing against fulcrum and
rockable about said fulcrum from a first position in which said
locking means engage said rod to lock said rod and said housing
against contractible movement and a second position allowing
freedom of axial movement of said rod, a locking spring encircling
said rod and partially compressed between said barrier and said
locking means, said locking spring exerting a force urging said
locking means toward said first position, a cam member rotatably
supported in said housing for selective direct engagement with said
locking means on the side of said rod opposite said fulcrum, and
actuating means for rotating said cam to move said locking means
against the force of said locking spring from said first position
to said second position.
6. The link assembly of claim 5, wherein said barrier means further
includes a pair of washers, each of said washers being positioned
in said chamber on opposite sides of and bearing against said
housing portions.
7. The link assembly of claim 5, wherein said housing has a
transversely extending slot formed therethrough, said fulcrum
comprising a portion of said housing immediately adjacent said slot
deformed radially inwardly into said chamber.
Description
BACKGROUND OF THE INVENTION
Position adjustors for reclining seat backs are well known and
widely are utilized in vehicles such as automobiles, buses and
airplanes. Historically, available position adjustors were equipped
with ratchet and pawl mechanisms. Because such mechanisms are noisy
in operation and allow for only a limited number of adjustment
positions, a demand arose for a silent adjustor allowing for an
infinite number of seat back positions. Attempts to satisfy this
demand with hydraulic actuators generally proved unsatisfactory
because hydraulic models proved either uneconomic or subject to
hydraulic fluid leakage problems.
In recent years, however, development was accomplished of an
actuator design using a previously known concept of a connecting
link including extensible rod arrangement that selectively is
locked or released by movement of a stack of tiltable washers
functioning as lock plates. Refinement of this concept produced a
design having the requisite compactness, light weight,
dependability and low cost necessary for commercial acceptance. An
example of such an actuator connecting link is taught by U.S. Pat.
No. 3,271,071, issued Sept. 6, 1966, and owned by the assignee of
this invention.
The actuator connecting link disclosed by this patent has somewhat
limited usage, however, because it is spring biased towards its
extended position and thus adapted for mounting within the seat
back for movement therewith and for extension into a lengthened
condition as the seat back is moved from an upright position toward
a reclining position. In certain vehicle reclining seats, however,
it is desirable for reasons of simplicity of design and packaging
of component parts to mount the actuator connecting link in the
horizontal seat bench. In such an arrangement, a simplified
actuator mechanism design is facilitated by providing that the
connecting link moves from an extended to a contracted condition as
the seat back swings towards a reclining position.
Additionally, it long has been recognized by motor vehicle product
development and marketing studies that the extent of commercial
acceptance for so-called "comfort and convenience items" such as
reclining seats is related in an inverse manner to the customer
cost for such items. A constant need, therefore, exists for new
designs for vehicle components such as seat back actuators that
retain high standards of reliability and performance but enable
cost savings in manufacture. Because of the many parts in actuator
connecting links, it especially is desirable for a link design to
provide for ease of manufacturing and assembly of the link by
workers having little in the way of special training. Such a goal
can be achieved if the link design allows formation of structure
located within the link housing by machining and working of the
housing from exterior thereof, and if all of the internal link
components easily may be slid within the housing during assembly
without the need for complex special operations or tooling.
It is, therefore, an object of this invention to provide extendible
and contractible connecting link assembly for a vehicle reclining
seat back actuator that normally is in an extended condition. A
further object of the invention is to provide a connecting link of
simplified design in which various internal structural features may
be formed by machining and working of the link assembly housing
from exterior thereof. A still further object of the invention is
to provide a connecting link design allowing assembly of many of
the component parts primarily by sliding these parts in proper
sequence within the link housing.
SUMMARY OF THE INVENTION
A selectively extendible and contractible reclining seat actuator
connecting link assembly designed and constructed in accordance
with this invention comprises a thin-walled, tubular housing having
an internal chamber. First plug means close one end of the housing
and second plug means having an aperture formed therethrough
partially close the other end of the housing. A rod extends through
this aperture and partially is slidably received in the housing.
Within the chamber are first stop means formed by diametrically
opposed portions of the housing wall deformed radially inwardly
into said chamber. A washer is positioned against said first stop
means with the rod extending through the central aperture of the
washer. The rod is formed with radially extending flange means
projecting therefrom inside the chamber. A main operating spring
surrounds the rod and is compressed between the washer and the
flange means and biases the rod out of the housing. This biasing of
the rod naturally provides for a biasing of the link assembly
towards an extended condition. A plurality of juxtaposed, centrally
apertured lock plates are positioned within the chamber with the
rod extending through the apertures therein. The lock plate
apertures are larger than the rod so that the lock plates can be
tilted relative to the rod. Second stop means formed by an inwardly
deformed portion of the assembly housing comprises a fixed fulcrum
offset from the axis of the rod and in contact with one of the lock
plates to prevent movement of the lock plates away from the end of
the housing from which the rod protrudes. A locking spring
encircles the rod and is compressed between a fixed portion of the
assembly and the side of the lock plates remote from the second
stop means. This locking spring is operative to tilt the lock
plates about the fulcrum and lock the rod and thus the housing
against contractible movement. A cam member is rotatably supported
in the housing for selective direct engagement with the lock plates
on the side of the lock plates away from the fulcrum. The cam
member may be rotated to move the lock plates against the force of
the locking spring until the locking plates are substantially
perpendicular to the axis of the rod thereby permitting free rod
movement in either direction.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side elevation view of a reclining vehicle
seat including the seat actuator extendible and contractible
connecting link assembly of this invention;
FIG. 2 is a top view of a connecting link assembly included in the
seat of FIG. 1;
FIG. 3 is a side view of the assembly of FIG. 2;
FIG. 4 is an end view of the assembly of FIGS. 2 and 3 taken along
the line of sight denoted by the arrow 4 of FIG. 3;
FIG. 5 is a section view taken along the line 5--5 of FIG. 3;
FIG. 6 is a section view taken along the line 6--6 of FIG. 3;
FIG. 7 is a side section view of the assembly of FIGS. 2 and 3
showing the assembly in an extended condition;
FIG. 8 is a view similar to FIG. 7, but showing the assembly in a
contracted position;
FIG. 9 is a bottom view of a portion of the assembly of this
invention; and
FIG. 10 is a bottom view of a portion of the assembly of this
invention; and
FIG. 11 is an exploded view of the parts of the manually operable
actuating mechanism of the connecting link assembly of this
invention.
DESCRIPTION OF THE DRAWINGS
Referring now in detail to the drawings and in particular to FIGS.
1-4 thereof, the numeral 12 denotes generally a vehicle seat
assembly of the reclining type. This seat includes a horizontal,
relatively stationary seat bench portion 14 and a substantially
upright seat back portion 16. Both the seat bench and back may be
provided with suitable upholstery padding. Seat back 16 is
pivotally secured to the seat bench 14 at pivot point 18 for
swinging movement into an infinite number of reclining positions.
The seat back actuator mechanism includes an extendible and
contractible connecting link assembly 20 adapted to interconnect
the seat bench and seat back and regulate relative movement
therebetween. In furtherance of this, assembly 20 is connected to
seat bench 14 at point 22 and at point 24 is connected to a sector
portion 26 of the seat back 16.
The assembly 20 comprises a main housing 28 closed at one end by a
plug 30. Integrally formed with the plug 30 is a projecting clevis
portion 32 apertured at 34 to facilitate the interconnection of
assembly 20 with seat bench 14 at point 22. The end of housing 20
remote from plug 30 is partially closed by plug 36 having a central
aperture 38 (FIGS. 7 and 8) extending therethrough. An elongate rod
40 extends through aperture 38 and is partially slidably received
in the housing 28. The free end of rod 40 has a threaded portion
40a of reduced diameter upon which is threadably received a clevis
42 suitably apertured at 44. Since clevis 42 is threadably received
on rod portion 40a and may be adjustably positioned therealong, the
effective length of rod 40 may be varied to accommodate variances
in tolerances of the parts of said seat assembly 12. A lock nut 46
also is received on rod portion 40a and secures clevis 42 in the
position desired.
Projecting laterally from housing 28 is a camshaft 48 having a
splined end 50. The free end of camshaft 48 is splined in order to
facilitate the mounting thereon of an operating handle (shown only
in FIG. 11 of the drawings), the purpose of which will be disclosed
in detail below.
The details of the construction and component parts of assembly 20
may be seen with particular reference to FIGS. 5-9 of the drawings.
There it may be seen that housing 28 is a thin-walled, integral
tube having a central passageway 29 extending therealong. The plug
30 has a main body 52 that extends into the tubular housing 28 and
has a circumferential groove 54 formed in the outer periphery
thereof. The extent to which body 52 may extend into housing 28 is
limited by the integrally formed plug flange 56 that bears against
the longitudinal extremity of the housing 28. Plug 30 is held in
place by the radially inward deformation of the wall of housing 28
at 58 into the plug groove 54. This deformation may be accomplished
by staking or other suitable means.
Plug 36, that partially closes the end of housing 28 remote from
plug 30, has a main body 60 with a circumferential groove 62 formed
about the outer periphery thereof. The plug body 60 extends into
housing 28 an amount limited by an integrally formed plug flange 64
that contacts the end extremity of the housing 28. Plug 36 is
locked into the position shown by the radially inward deformation
of the wall of housing 28 at 66 into the groove 62. This
deformation may be accomplished by staking or other suitable
means.
As best may be seen in FIGS. 2, 3, 9 and 10, a pair of spaced apart
slots 68 and 68a are formed through the wall of housing 28.
Diametrically opposed from the position of slots 68 and 68a, a pair
of corresponding spaced apart slots 70 and 70a also are formed
along the housing wall. The housing wall portion between slots 68
and 68a comprises the web 72 while the web 74 is located between
slots 70 and 70a. Both webs 70 and 72, as best may be seen from
FIGS. 6 and 9, are deformed radially inwardly to form stop means
located within the passageway 29 that extends the length of housing
28. A washer 76 having an outside diameter less than the inside
diameter of housing 28 and a central aperture 76 is positioned
against the left side of webs 72 and 74 as viewed in the drawings.
Rod 40 extends through the washer hole 76 that is sufficiently
larger than the diameter of the rod to permit free and easy
movement of the rod through this aperture.
The portion of rod 40 within passageway 29 carries a snap ring 80
that is received in a peripheral groove 82 formed in rod 40. A
washer 84 surrounds rod 40 and bears on right side of snap ring 80.
The purpose of snap ring 80 and washer 84 is to form a radially
extending flange means that projects from the rod 40. Accordingly,
it should be understood that such flange means could be formed by
simply increasing the outside diameter of the snap ring 80 or by
welding a washer to the rod 40, expedients that would be the full
equivalent of the snap ring and washer arrangement illustrated.
Partially compressed between the washers 76 and 84 is an operating
coil spring 86. It readily may be understood that the force exerted
by spring 86 biases the rod 40 towards the left as viewed in the
drawings into an extended condition relative to the housing 28.
Movement of rod 40 to the left due to the force of spring 86 is
limited by contact between the snap ring 80 and the inner surface
of body 60 of plug 36. Such contact occurs when assembly 20 is in
the fully extended condition as occurs when seat back 16 is in the
upright position illustrated in FIG. 1.
A laterally extending slot 88 is formed through the wall of housing
28 and is located between web 72 and plug 30. A portion 90 of the
wall of housing 28 adjacent slot 88 on the side of this slot
proximate plug 30 is deformed radially inwardly and projects into
passageway 29. This inwardly deformed wall portion 90 functions as
a fulcrum for the assembly locking means. These locking means
comprise a stack of juxtaposed lock plates or washers 92 (six
shown) having central apertures formed therethrough having a
diameter only slightly larger than the diameter of the rod 40. Rod
40 extends through the lock plates 92 in a sliding fit. One of the
stack of lock plates 92 bears against fulcrum 90 and thus is
prevented from movement towards the right as viewed in the
drawings. A locking coil spring 94 is partially compressed between
lock plates 92 and a washer 96 through which rod 40 extends. The
washer 96 bears on the sides of webs 72 and 74 remote from washer
76. The central aperture of washer 96 is sufficiently large to
permit free movement of the rod therethrough.
Referring now to FIGS. 5, 9, 10 and 11, it may be seen that a large
transversely extending slot 98 is formed through the wall of
housing 28. A cam release mechanism, denoted generally by the
reference numeral 100, partially is received in slot 98 as will be
described in detail below.
Mechanism 100 includes the camshaft 48 having a portion of reduced
diameter 102. Extending from camshaft portion 102 is a cam lobe
104. Camshaft portion 102 is received in slot 98 so cam lobe 104 is
located within passageway 29.
A pair of pins 106 and 108 extend through diametric bores formed
through camshaft portion 102 and project from these bores. It is to
be understood, however, that projections integrally formed with
camshaft portion 102 would be the full equivalent of pins 106 and
108.
A U-shaped bracket 110 serves to hold the camshaft 48 so that
camshaft portion 102 is rotatably positioned within the slot 98.
Bracket 110 has a generally flat main body 112 that is in contact
with the outer surface of the bottom of housing 28. This position
of bracket 110 may be maintained solely by the fastener means
described below or by a combination of fastener means and adhesive
bonding between body 112 and the outer surface of assembly housing.
Upwardly projecting legs 114 and 116 extend from main body 112 and
have formed therein downwardly extending slots 118 and 120
respectively. Slots 118 and 120 are suitably dimensioned to receive
the extremities of camshaft portion 102 that project from slot 98.
The inner surface of legs 114 and 116 are in intimate contact with
the arcuate wall of housing 28.
Main body 112 has formed therethrough a pair of slots 122 and 124
that receive pins 108 and 106 respectively. This interrelationship
between slots 122 and 124 and pins 108 and 106 serves to limit the
magnitude of angular rotation of camshaft 48 as best may be seen in
FIG. 9. An aperture 126 also extends through bracket main body 112
and is aligned with a similar aperture 127 (FIG. 9) formed through
housing 28.
Against the outside (bottom) surface of bracket main body 112 is
positioned a leaf spring 128 having an aperture 130 formed
therethrough. Leaf spring 128 and bracket 110 are held in position
by a machine screw 132 that extends through apertures 130, 126 and
127, thereby fastening the leaf spring and bracket to the housing.
Leaf spring 128 overlies the slots 122 and 124 and thus bears
against the portions of pins 108 and 106 that extend through these
slots. The purpose of spring 132 will be explained in detail
below.
The manual operating handle 134, having a splined bore 136 is
received on the splined end 50 of camshaft 48 for unitary rotation
therewith.
In operation, the assembly 20 serves to regulate pivotal reclining
movement of the seat back 16 relative to the seat bench 14. With
the seat back 16 in the upright position illustrated in FIG. 1, the
assembly 20 is in the fully extended condition illustrated in FIG.
7 of the drawings. Downward pivotal movement of said back 16 in a
counterclockwise direction is prevented since the force of locking
spring 94 acts upon lock plates 92 and tilts these plates about
fulcrum 90 causing the sharp edges of the lock plate central
apertures to engage the rod 40. If the vehicle seat occupant
desires to adjust the seat in a reclining position, the operator
grasps handle 134 and rotates this handle causing counterclockwise
rotation of the camshaft as viewed in FIGS. 7, 8 and 9. The cam
lobe 104 contacts the lock plate proximate to the camshaft and
forces the stack of lock plates 92 into a position substantially
perpendicular to the axis of rod 40. With the lock plates so
positioned, rod 40 may move unimpeded to the right as viewed in the
drawings and seat back 16 may be pivoted counterclockwise against
the force of operating spring 86.
When the desired seat back position of adjustment is achieved, the
seat occupant releases handle 134. The force of locking spring 94,
together with the force of leaf spring 132 acting on pins 106 and
108, will cause the camshaft to return to the position shown in
FIG. 7 and allow tilting of the lock plates about fulcrum 90,
thereby preventing further reclining movement of the seat back.
When it is desired to return the seat back to the upright position,
the seat back need only be grasped manually and moved to this
upright position since the frictional force between the lock plates
92 and rod 40 tending to prevent movement of the rod 40 to the left
as viewed in the drawings is not great and may be overcome
manually.
It should be noted that leaf spring 128 also serves to prevent
movement of the camshaft when the camshaft is not operating to
position thy plates 92. With the camshaft thus inoperative, it is
in an unstressed condition and free to move within slot 98. Such
movement would cause an undersirable rattling absent the force
exerted by spring 128.
The design of the assembly 20 disclosed herein is particularly
advantageous in that it allows for the efficient assembly of the
many parts of this device by a relatively untrained workman
utilizing only simple tools. Prior to assembly, the tubular housing
28 has formed therein slots 68, 68a, 72, 72a, 88 and 98. These
slots simply may be formed by well known machining techniques such
as sawing or milling. Also prior to assembly, the housing wall
portion 90 is deformed radially inwardly to form the required
fulcrum. The first assembly operation comprises the assembly of the
actuating mechanism 100, the parts of which are shown in FIG. 11.
This is accomplished simply by proper positioning of the parts and
the insertion of the machine screw 132. If, as noted above, it is
desired to position the bracket on the housing 28 by the use of an
adhesive, this operation can be added.
The assembly of the parts located in the passageway 29 greatly is
facilitated due to the fact that all of these parts have outside
diameters less than the inside diameter of the tubular housing 28.
Thus assembly of these parts may commence by a workman simply
dropping the stack of lock plates 92 into the passageway 29. These
plates, due to the force of gravity, will come to rest in the
desired juxtaposed stack against the fulcrum 90 and camshaft
portion 102. The locking spring 94 and washer 96 then are placed in
passageway 29. Such force is applied to washer 96 to partially
compress the spring 94 and with the spring held in this partially
compressed condition the webs 72 and 74 are deformed radially
inwardly to lock washer 96, partially compressed spring 94 and
locking plate stack 92 into position. Washer 76 and operating
spring 86 then are placed in passageway 29. Rod 40, with washer 84
and lock washer 80 previously positioned thereon, then is inserted
through operating spring 86, washers 72 and 96, spring 94 and
locking plates 92. Rod 40 is inserted a sufficient distance within
the housing to partially compress the spring 86. While the rod is
held in this position, the plug 36 is positioned and secured at the
end of the housing by the deformation inwardly of the housing at
66. Plug 30 then may be positioned in the opposite end of housing
28 and locked in place by the inward deformation of the housing at
58. Lock washer 46 and clevis 42 then are added to complete the
assembly 20.
It thus may be seen that this invention provides an extendible and
contractible connecting link assembly for a vehicle reclining seat
back actuator that normally is spring biased towards its extended
position, thus allowing this mechanism to be positioned in the
stationary seat bench as illustrated in FIG. 1 of the drawings. The
device herein disclosed is of simplified design in which various
internal structural features, such as webs 72 and 74 providing stop
shoulder means and the fulcrum 90, may be formed by deformation of
the housing from exterior thereof. Also, the design of this
invention allows a simple assembly of the plurality of component
parts primarily by sliding these parts in proper sequence within
the assembly housing.
* * * * *