U.S. patent number 3,847,338 [Application Number 05/335,528] was granted by the patent office on 1974-11-12 for adjustable height seat.
This patent grant is currently assigned to A. W. Chapman Limited. Invention is credited to Albert John Adams.
United States Patent |
3,847,338 |
Adams |
November 12, 1974 |
ADJUSTABLE HEIGHT SEAT
Abstract
Mechanism operable to adjust the height of the seat in relation
to the vehicle floor. The mechanism includes crossed levers
arranged in pairs with the inner levers of the two pairs connected
to one another by a torsion rod. The two pairs of levers are
connected to one another by a transverse pivot shaft and
corresponding ends of the outer levers of the pairs are connected
to sliding pivot blocks. Wedge-shaped or cam-action plates arranged
inwardly of the lever pairs are slidably connected to said shaft
and also to a crossbrace assembly which is slidably forwardly and
rearwardly of the seat relative to said pairs of crossed levers by
means of a screw and nut mechanism.
Inventors: |
Adams; Albert John (Middlesex,
EN) |
Assignee: |
A. W. Chapman Limited (London,
EN)
|
Family
ID: |
9862341 |
Appl.
No.: |
05/335,528 |
Filed: |
February 26, 1973 |
Foreign Application Priority Data
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Feb 26, 1972 [GB] |
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8944/72 |
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Current U.S.
Class: |
248/419 |
Current CPC
Class: |
B60N
2/164 (20130101); B60N 2/162 (20130101) |
Current International
Class: |
B60N
2/16 (20060101); F16m 013/00 () |
Field of
Search: |
;248/399,419,421 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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894,343 |
|
Apr 1962 |
|
GB |
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1,107,915 |
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May 1961 |
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DT |
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537,355 |
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Jun 1941 |
|
GB |
|
Primary Examiner: Schultz; William H.
Attorney, Agent or Firm: Berman, Bishoff & Platt
Claims
What I claim as my invention and desire to secure by Letters Patent
of the United States is:
1. An adjustable height seat which includes a seat frame having
spaced side members and spaced front and rear members all of which
are rigidly connected to one another; two spaced lever pairs
disposed parallel to one another in substantially vertical planes,
the inner lever of one lever pair being connected to the inner
lever of the other lever pair by a torsion rod having
non-circular-section ends extending through complementary holes in
said inner levers and being rivetted thereto; the levers in each
lever pair being pivotally connected to one another in
X-configuration by a shaft extending through the two spaced lever
pairs, said shaft being spaced from and non-coaxial with said
torsion rod; corresponding one ends of corresponding one levers of
each lever pair being pivotally rivetted directly to corresponding
ones of said seat frame members; corresponding one ends of the
corresponding other levers of each lever pair being connected by
pin-and-slot connections directly to said corresponding ones of
said seat frame members at locations spaced from the rivetting of
the ends of said corresponding one levers thereto, the pin being
carried by the lever and the slot being formed in the seat frame
member; the corresponding other ends of said corresponding one
levers of each lever pair having a pin-and-slot connection with
bracket members, the pin being carried by the lever and the slot
being formed in the bracket member; the corresponding other ends of
said corresponding other levers of each lever pair being rivetted
to other bracket members which are spaced from the first-mentioned
bracket members; two wedge-shaped plates generally vertically
disposed in the vicinities of each lever pair and located inwardly
of the lever pairs, each of said wedge-shaped plates having
vertically separated non-parallel edges with flanges thereon which
are substantially normal to the general plane of the plate, the
flanges at one of said edges engaging a slide secured to the
respective seat frame member and the flanges at the other of said
edges engaging a wedge retaining block formed solely of a synthetic
resin material having a low coefficient of friction which is
supported by said shaft, each of said wedge retaining blocks being
formed with a bore for the accommodation of part of said shaft and
with a slot at right angle to and spaced above said bore for the
guided sliding of ssid flanges at said other edges, each
wedge-shaped plate having freedom for sliding movements relative
both to said shaft and to said seat frame and being so slidably
mounted with the interposition of additional elements of synthetic
resin material having a low coefficient of friction between metal
parts, said wedge-shaped plates being interconnected centrally by a
connecting piece which carries a nut of a screw and nut mechanism,
whereby rotation of the screw in the nut will cause displacement of
said wedge-shaped plates relative to said shaft and said seat frame
to alter the angular relationships between the levers of each lever
pair as permitted by said pin-and-slot connections, with resultant
adjustment of the spacing between the said bracket members and the
seat frame.
2. An adjustable height seat as claimed in claim 1, wherein said
additional elements of synthetic resin material having a low
coefficient of friction include elements which are interposed
between the flanges at said one of said edges and the slides with
which said flanges coact.
3. An adjustable height seat as claimed in claim 1, wherein each of
said wedge retaining blocks comprises a body having a rectangular
base as its upper surface, and a depending portion of triangular
cross-section said bore passing through said body from end to end,
and said slot being formed in said upper surface and lying in a
direction transverse to said bore.
Description
This invention relates to motor vehicle seats having means operable
to adjust the height thereof.
It is the principal object of the present invention to provide an
adjustable height seat whose overall weight is reduced compared
with that of conventional adjustable height seats whose
manufacturing cost is lower than that of a conventional seat and
which will not give rise to an objectionable degree of
scuffing.
Accordingly, the present invention consists in an adjustable height
seat which includes a sea frame having spaced side members and
spaced front and rear members all of which are rigidly connected to
one another; two spaced lever pairs disposed parallel to one
another in substantially vertical planes, the inner lever of one
lever pair being connected to the inner lever of the pair by a
torsion rod whose non-circular-section ends extend through
complementary holes in said inner levers and are rivetted thereto;
the levers in each lever pair being pivotally connected to one
another in X configuration by a shaft extending through the two
spaced lever pairs; corresponding one ends of corresponding one
levers of each lever pair being rivetted to corresponding ones of
said seat frame members; corresponding one ends of the
corresponding other levers of each lever pair being connected by
pin-and-slot connections to said corresponding ones of said seat
frame members at locations spaced from the rivetting of the ends of
said corresponding one levers thereto, the pin being carried by the
lever and the closed slot being formed in the seat frame member;
the corresponding other ends of said corresponding one levers of
each lever pair having a pin-and-slot connection with bracket
members, the pin being carried by the lever and the closed slot
being formed in the bracket member; the corresponding other ends of
said corresponding other levers of each lever pair being rivetted
to other bracket members which are spaced from the first-mentioned
bracket members; two wedge-shaped plates generally vertically
disposed and located in the vicinities of each lever pair and
located inwardly of the lever pairs, each wedge-shaped plate having
freedom for sliding movements relative both to said shaft and to
said seat frame members and being so slidably mounted with the
interpostion of elements of synthetic resin material having a low
coefficient of friction between metal parts; said wedge-shaped
plates being interconnected by a connecting piece which carries a
nut of a screw and nut mechanism; whereby rotation of the screw in
the nut will cause displacement of said wedge-shaped plates
relative to said shaft and said seat frame members to alter the
angular relationships between the lever of each lever pair as
permitted by said pin-and-slot connections, with resultant
adjustment of the spacing between the said bracket members on the
one hand and the seat frame members on the other hand.
In a preferred embodiment of said adjustable height seat, each of
said wedge-shaped plates has at its vertically separated
non-parallel edges flanges which are substantially normal to the
general plane of the plate, the flange or flanges at one of said
edges engaging a guide secured to the respective seat frame member
and the flange or flanges at the other of said edges engaging a
shaped wedge block, which is supported by said shaft. Preferably,
each of said wedge blocks is made of DELRIN (Registered Trade Mark)
whereas one or more elements of DELRIN are interposed between said
guide and the flange or flanges which are at said one edges of the
wedge-shaped plates.
Again, preferably, the pin-and-slot connections between said lever
ends and the seat frame members and the bracket members are by way
of a sliding pivot blocks connected to the lever ends and slidable
along said closed slots.
Said bracket members are securable in any desired manner to the
slides of slide and guide assemblies of which the guides are
securable to the vehicle floor to permit fore and aft movements of
the whole seat. The seat may also be provided with releasable stop
means operable to secure the whole seat in any position (fore and
aft of the vehicle) to which said seat has been moved.
The present invention will now be more particularly described with
reference to the accompanying drawings in which:
FIG. 1 illustrated in front elevation an adjustable height seat
mounted upon a seat slide mechanism which permits fore and aft
movement of the entire seat;
FIG. 2 illustrates a top plan view of the assembly illustrated in
FIG. 1;
FIG. 3 illustrates a side elevation of the assembly illustrated in
FIG. 1;
FIG. 4 illustrates a section on a medial plane through a wedge
retaining block; and
FIG. 5 is a half section on the line V--V in FIG. 4, showing
clearly the cross-sectional shape of the slot with which said block
is formed.
Referring to the drawings, there is illustrated a seat frame 10
which consists of interconnected side members 11, 12 and front and
rear members 13, 14. All of said members, 11,12,13, are of angle
section. Secured to the underside of the side members 11, 12 in
transversely aligned positions are two parallel slides, 15, 16,
said slides being so secured as by the rivets 17 illustrated. Two
wedge-shaped plates 18, 19 have outwardly turned flanges at their
opposed non-parellel edges, the flanges indicated by the reference
numeral 20 having slide pads 21 made of DELRIN fitted thereto and
said pads being arranged in the relevant one of the slides 15, 16.
The flanges indicated by the reference numeral 22 are engaged by
and are arranged for movement in a wedge retaining block 23 in a
manner and for a purpose which will be hereinafter described.
The wedge-shaped plates 18, 19 are connected to one another by a
crossbrace 24 both of whose ends are formed to provide two tongues
25 which extend through complementary holes in said plates and are
then peened over upon assembly, said tonuges only being illustrated
at one end of the crossbrace 24 in FIG. 2. The plates 18, 19 must
be set parallel to one another and the crossbrace 24 must be at
right angles to each of said plates. The crossbrace carries a nut
26 whose internal thread engages the external thread of a screw 27.
A nut and washer 28 is screwed on to one end of the screw 27 and
said screw extends through a thrust bearing 29 which is supported
in a part of the front member 13. The portion of the bearing 29
which extends into said part of the front member 13 is of
non-circular section (e.g., square with the corners of the square
chamfered off) as also is the hole in which it is accommodated so
that said bearing is prevented from rotating when the screw 27 is
rotated. An E-clip 30 maintains the relative positions of the screw
27, the bearing 29 and the relevant part of the front member
13.
The front end of the screw 27 is provided with a crank handle 31
and it will be seen that rotation of said handle 31 will cause
displacement of the plates 18, 19 and the pads 21 along the slides
15, 16.
Two spaced lever pairs are provided, outwardly of the plates 18, 19
which are disposed parallel to one another in substantially
vertical planes and one of said lever pairs is visible in FIG. 3.
Each lever pair consists of a so-called inner lever 32 and a
so-called outer lever 33 which are connected to one another in X
configuration by a shaft 34 which extends tranversely right across
the seat frame.
The rear end of the lever 33 is pivotally connected at 35 to the
vertically disposed web of the relevant side member 11 or 12. By
contrast, the front end of the lever 32 is pivotally connected to a
sliding block 36 of which a part extends through an elongated slot
37 formed in said vertically disposed web.
In a similar manner, the rear end of the lever 32 is pivotally
connected at 38 to the relevant one of two vertically arranged lugs
39 of a bracket 40 which are secured to two slides 41 as by nuts 42
which are screwed on to bolts 43 which could be integral with said
slides. Another crossbrace 44 is secured to said slides 41 in a
manner similar to that just described and said crossbrace 44 has
vertically arranged lugs 45 having elongated slots 46 formed
therein. The front end of the lever 33 is pivotally connected to a
sliding block 47 of which a part extends through said elongated
slot 46.
It will be appreciated that the arrangement described in the two
preceding paragraphs for the lever pair which is visible in FIG. 3
is repeated for the lever pair which is disposed at the other side
of the seat frame.
The two inner levers 32 are provided with non-circular section
holes (for example, square holes) through which there extend the
opposite ends of a torsion shaft 48, said ends of said shaft being
of a section complementary to that of said holes. Said shaft ends
are peened over on to said inner levers to make said levers 32 and
the shaft 48 into a unitary structure.
The shaft 34 carries the two wedge retaining blocks 23 which were
referred to above and which are to be seen in FIGS. 1, 3, 4 and 5.
It will be seen from FIG. 4 that each block 23 is formed to provide
a sleeve portion having a bore 49 therethrough, through which the
shaft 34 is intended to extend, and a slot 50 which extends in a
direction at right angles to the longitudinal axis of said bore 49.
The slot 50 is intended to accommodate the opposed flanges 22 of
the relevant wedge-shaped plate 18 or 19 as can clearly be seen in
FIG. 1. The blocks 23 are made of a material having a low
coefficient of friction (for example, DELRIN) and said blocks are
maintained in their correct positions on the shaft 34 by circlips
51.
Rotation of the handle 31 in the appropriate direction will cause
the screw 27 to rotate in the nut 26 which is fixed to the
crossbrace 24 and this will result in the plates 18, 19 being drawn
towards the front of the seat frame. The pads 21 on the flanges 20
of said plates will slide along and within the slides 15, 16 and
the flanges 22 of said plates will slide along and within the slots
50 in the blocks 23. As will be evident from FIG. 3, any sliding
movement of the plates 18, 19 relative to the blocks 23 must result
in vertical displacement of the seat frame towards or away from the
slides 41 and, in the particular case being considered, said seat
frame 10 will be moved away from said slides 41, thereby raising
the seat frame. The resultant vertical movement of the shaft 34
accommodated or permitted by movement of the several sliding blocks
36, 47 along the associated slots 37, 46.
The mechanism permitting fore and aft movements of the entire seat
has not been described except for the slide 41 because such
arrangements are well-known and do not form part of the present
invention. Similarly, it is not thought to be necessary to describe
the manner in which the guide rail parts of such mechanism are
secured to the vehicle floor, nor the manner in which the seat pan
itself is secured to the members 14, 52.
* * * * *