Note: Descriptions are shown in the official language in which they were submitted.
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A Rocking Chair Mechanism
The present invention relates to a laterally-slim, arm-incorporated rocking
chair
mechanism.
Spring-assisted rocking chairs are well-known, in which a seat (that normally
consists of a
supporting surface on which the sitter sits, a back rest and two arms,
collectively referred to
as "seat") having rotating bearers (commonly known as "rockers") is unstably
mounted on
a stationary base, using springing means to achieve stability and to sustain
the traditional
oscillating rocking chair movement, such as the rocking chair illustrated in
Figure 1 and
the rocking chair mechanism illustrated in Figure 2.
In EP 1211967 the rotating rockers are raised a long way from floor level and
located
within the arms of the chair, which provides a solution for the safety hazard
of fingers or
toes being pinched by the exposed rotating rocker and stationary base, and
also provides
the design advantage of being able to design open-base rocking chairs - which
have a more
modem look - as opposed to boxed or skirted chairs.
However, traditionally the springing means are connected to the side of the
rotating rocker,
as illustrated in Figure 2, in which case the cubic space of the rotating
rocker is laterally
attached to the cubic space of the springing means. Normally, this is not a
problem but if
the rotating rocker and the springing means are located within the arm of the
chair - side by
side - the width of each arm would have to be wide enough to incorporate the
width of the
rotating rocker and the width of the springing means, which adds up to the
overall width of
the chair. Although the issue of the overall width of the chair can be
aesthetically designed
around with relative ease, there are other impractical inconveniences, for
example the chair
taking up more space during transportation than otherwise, which adds to the
cost, or the
chair being relatively difficult to carry through narrow doorways.
An object of the present invention is to provide a solution as claimed in
Claims 1, and 2.
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Figure 2 is a perspective view of a traditional rocking chair mechanism that
consists of a
rotating rocker A, a stationary base B and a springing means C.
All subsequent Figures relate to the present invention.
Figure 3 is a side view of one possible way of constructing the invention,
illustrating
rocking chair mechanism 1 that consists of a rotating rocker 2, a stationary
support 3, a
springing means 4, an upper assembly 5, and a lower assembly 6. Springing
means 4 are
illustrated here as two extension springs. To increase the ease of the rocking
chair
movement, preferably, stationary support 3 is curved.
Figure 4 is a frontal elevation of the same rocking chair mechanism as in
Figure 3. As
illustrated, the cubic space of rotating rocker 2 and the cubic space of
springing means 4
are laterally integrated, hence considerably reducing the width of the rocking
chair
mechanism. Although Figure 4 illustrates a mechanism in which the vertical
axis of
rotating rocker 2 and the vertical axis of springing means 4 are in one plane,
this is not
necessary but is only a preferred option as it maximizes lateral integration,
and
alternatively they can be in two different planes, as long as there is a
degree of lateral
integration between the cubic space of rotating rocker 2 and the cubic space
of springing
means 4, as opposed to being side-by-side as illustrated in Figure 2.
Figure 5 is a perspective view of the same rocking chair mechanism as in
Figures 3 and 4.
Figure 6 is a diagrammatic perspective of a rocking chair 7, that incorporates
two laterally
integrated rocking chair mechanisms I (one mechanism within each of the two
arms) by
connecting each upper assembly 5 to seat 7a and connecting each lower assembly
6 to
stationary base 7b, so that seat 7a can move (along with upper assembly 5 and
rotating
rocker 2) in relation to stationary base 7b (and lower assembly 6 and
stationary support 3).
As illustrated, the chair has an open-base (as opposed to boxed or skirted
chairs) and the
bottoms of the anus 7c are noticeably above floor level.
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Figures 7 to 20 are side views of different other ways of constructing the
invention.
In Figure 7 the springing means consist of compression spring 4a and extension
spring 4b.
Figure 8 is an illustration of a mechanism similar to the mechanism in Figure
7, except
that the axis of each spring is angled to accommodate the direction of
movement.
Figure 9 is an illustration of a mechanism similar to the mechanism in Figure
3, except
.that stationary support 3 is not curved but is a flat surface that is shown
here as being
sloped downwards (towards the back rest).
Figure 10 is an illustration of a mechanism similar to the mechanism in Figure
3, except
that rotating rocker 2 is not curved but is a flat surface.
Figure 11 is an illustration of a mechanism similar to the mechanism in Figure
3, except
that the springing means consists of two compression springs 4a.
Figure 12 is an illustration of a mechanism similar to the mechanism in Figure
7, except
that compression spring 4a is not connected to upper assembly 5, and therefore
only comes
into action as a result of the weight of the sitter.
Figure 13 is an illustration of a mechanism similar to the mechanisms in
Figures 7 and 12,
except that springing means 4a is a nest of two springs, the lower of the two
of which only
comes into action as a result of the weight of the sitter being above a given
weight, to be
determined by the designer.
Figure 14 is an illustration of a mechanism similar to the mechanism in Figure
3, except
that the curve of rotating rocker 2 is roughly a quarter of a circle, whose
diameter is
relatively small.
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Figure 15 is an illustration of a mechanism similar to the mechanisms in
Figures 3 and 14,
except that the curve of rotating rocker 2 is roughly half a circle, whose
diameter is
relatively small. It should be noted that the active part of the surface of
rotating rocker 2 is
only roughly a quarter of a circle (more or less the same as in Figure 14).
Figure 16 is an illustration of a mechanism similar to the mechanisms in
Figures 3,14 and
15, except that rotating rocker 2 is shown as a complete circle - which can be
a wheel or a
roller - whose diameter is relatively small. Two things need to be highlighted
here. First,
the active part of the surface of rotating rocker 2 is only roughly a quarter
of a circle (more
or less the same as in Figures 14 and 15). Second, the circumference of the
wheel or the
roller is fixed in relation to its centre and as such the wheel or the roller
is not used as a
wheel or a roller (whose circumference rotates around its centre) but only as
a curved
surface. The primary reason for considering the use of a wheel or a roller in
such a manner
is simply as a convenient way of reducing manufacturing costs by using off-the-
shelf mass-
produced wheels or rollers instead of manufacturing rotating rocker 2 as a
special
component.
In Figure 17 rotating rocker 2 is shown as a circle, which can be a wheel or a
roller
(similar to Figure 16), except that here the circumference of the wheel or the
roller is free
to rotate around its centre, and therefore the wheel or the roller is used as
a wheel or a
roller that moves on the curved surface of stationary support 3. The
illustration also shows
wheel/roller bracket 8, compression spring 4a and extension spring 4b.
Figure 18 is an illustration of a mechanism similar to the mechanism in Figure
17, except
that both compression spring 4a and extension spring 4b are fixed in
horizontal positions.
The illustration also shows block 9a which is connected to upper assembly 5
and block 9b,
which is connected to lower assembly 6, both of which blocks provide a firm
forward stop
when the sitter leans forward to vacate the chair.
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In both the mechanisms that are illustrated in Figures 17 and 18, the rotation
of the seat is
achieved by the movement of the wheel or the roller in relation to stationary
support 3,
which in this case must be curved as illustrated, otherwise the movement of
the seat will be
linear and therefore make the chair a gliding chair rather than a rocking
chair, whose
movement is - by definition - rotational. Given that the rotation of the seat
in this case is
created - solely - by the curve of stationary support 3, it is also possible
to have more than
one wheel or roller acting - collectively - as rotating rocker 2 and moving in
relation to
stationary support 3.
In Figure 19 rotating rocker 2 is the outer circumference of a ball or roller
bearing and
stationary support 3 is the inner circumference of the same ball or roller
bearing. Also
illustrated are housing 10 that connects rotating rocker 2 to upper assembly
5, bracket i 1
that connects stationary support 3 to lower assembly 6, compression spring 4a
and
extension spring 4b.
Alternatively, when a ball or a roller bearing is used the designer will have
the option of
using the inner circumference of the bearing as rotating rocker 2 and
consequently connect
it to upper assembly 5 and the outer circumference of the bearing as
stationary support 3
and consequently connect it to lower assembly 6.
Although it is traditional for the rotating rocker to be curved at both ends -
such as rotating
rocker A in Figure 2 - this is not actually necessary and may even be
perceived as
inconvenient by some chair users. The reason is that the rocking chair
movement is mainly
required when the sitter is sitting back in the seat i.e. the backward and
forward rocking
chair movement is mainly required - and is enjoyed most - between a point
where the sitter
is sitting substantially upright or slightly reclined and another point
further back. However,
when the sitter starts to lean forward to vacate the chair it may be
inconvenient for her/him
if the rocking chair movement is also accessible.
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This is why Figures 3, 5 and 7-19 illustrate a mechanism that provides a
restricted range
for the rocking chair movement and a firm forward stop when the sitter leans
forward to
vacate the chair. Such a firm forward stop is achieved in one or more way.
Having
extension springing means in front of the movement means that when the sitter
leans
forward to vacate the chair the extension springing means will become
completely closed
and will provide a firm stop. In the cases where there is no extension
springing means in
front of the movement, straight extensions can be added to rotating rocker 2
and to
stationary support 3 so that the straight extensions will provide a firm
forward stop, for
example as in Figure 11. Such straight extensions can also be used even if
there are
extension springing means in front of the movement, for example as in Figures
3, 5, 7-10
12-14. In the cases where there is neither extension springing means in front
of the
movement nor a possibility of adding straight extensions to rotating rocker 2
and to
stationary support 3, two blocks can be used to achieve the same effect, for
example as
illustrated in Figure 18.
As indicated above, it may be inconvenient for the sitter if the rocking chair
movement is
accessible when she/he leans forward to vacate the chair. Nevertheless, if the
designer has a
reason why the rocking chair movement should also be accessible when the
sitter is leaning
forward, then assemblies 5 and 6 can easily be of such extended length that
another set of
rotating rocker 2 and stationary support 3 can be located on the other side of
springing
means 4. Furthermore, there is the option of having rotating rocker 2
manufactured as one
component of extended length that has a cut out roughly in the middle for
springing means
4 to be located inside, and similarly having stationary support 3 manufactured
as one
component of extended length that has a cut out roughly in the middle for
springing means
4 to be located inside. Such an alternative approach is shown in Figure 20,
which
illustrates a mechanism similar to the mechanism in Figure 3, except that
rotating rocker 2
and stationary support 3 are of such extended length that they provide a
continuous surface
that allows the rocking chair movement when the sitter is leaning forward as
well as when
sitting substantially upright or reclining. As illustrated, springing means 4
are located
inside a cut out in both rotating rocker 2 and stationary support 3.
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Rocking chair mechanism 1, which is illustrated in Figures 3-5 and 7-20, is an
independent
unit that can be manufactured separately then supplied to rocking chair
manufacturers to be
incorporated into their rocking chairs. Alternatively, a laterally integrated
rocking chair
mechanism can be part of the construction of the rocking chair itself. In
either case,
stationary support 3, lower assembly 6 and upper assembly 5 are all preferred
options, as
suitable springing means 4 can be directly attached to both a specially
adapted stationary
base (such as chair base 7b in Figure 6) and to a specially adapted seat (such
as seat 7a in
Figure 6), with rotating rocker 2 being attached directly to seat 7a so that
it can move
directly onto stationary base 7b.
Figures 3, 5, 7-12 and 14-20 show a pair of springs in each mechanism.
Alternatively, it is
possible to use one spring of suitable strength or three or more springs of
equivalent
strength in various alternative vertical and horizontal arrangements. Other
types of
springing means can be used such as torsion, clock or waive springing means.
The
rotational movement can be achieved by virtue of a variety of mechanical
means, including
but not limited to: bearers (such as traditional rocking chair rotating
bearers), hinges,
pivots, pin assemblies, bearings (including ball, roller, or air bearings),
continuously
variable joints and other forms of rotary joints or coupling.
