Field of the invention
[0001] The present invention relates to a bench with a laterally movable seat, in particular
a piano bench.
Background
[0002] In order to reach the extreme areas of a worktable or a keypad of a musical instrument,
in particular a piano, a user or an artist sitting on a fixed seat has to twist his
back and exert a biased effort with his arms in the desired direction. Such repeated
biased movements may cause undesired tensions in the musculoskeletal system, and in
the particular case of playing the piano, the twisted position of the artist may cause
difficulties in playing forcefully. Laterally movable seats allow the user to conveniently
reach the desired extreme areas of the worktable or the piano keys while sitting in
an ergonomic and comfortable posture.
[0003] The document
US 3,718,365 discloses a seat attachment for boats which includes a fixed main frame and a laterally
slidably adjustable subframe holding a seat. Two parallel tubular members of the subframe
are slidingly sleeved on the two parallel tubular guiding members of the main frame.
Although the closed cylindrically shaped contact surfaces arranged in parallel ensure
a specific direction of the sliding movement, this type of guiding has the drawback
that there is a large friction between the sliding surfaces and the fixed surfaces
of the tubular members. Thus, an increased effort is required to slide the seat when
a user is sitting on it. Moreover, it leads to the early wearing of the contact surfaces.
This contact friction could be overcome by changing the diameter of either the male
cylinder or the female cylinder in order to reduce the area of the contacting surfaces.
However, the play on the remaining circumference of the sleeved cylinders not in contact
with each other may cause some noise during the sliding movement.
[0004] The document
US 1,290,517 discloses a bench having a laterally movable seat. The seat is provided with wheels
rotatably mounted on axles configured to engage with two longitudinally extending
parallel rails. Although the wheels provide a rolling contact instead of a frictional
contact, this arrangement does not comprise any guiding means against the play of
the wheel mechanism in a direction perpendicular to the motion of the seat. Furthermore,
since the wheels are mounted on the movable seat, the guiding rails are much longer
than the width of the seat, which results in a cumbersome bench arrangement.
Summary of the invention
[0005] It is an object of the invention to improve the laterally movable seats of the prior
art.
[0006] It is an object of the invention to provide a bench with a laterally movable seat
which can be stably moved with little effort when a user is sitting on it.
[0007] It is a further object of the invention to provide a bench with a laterally movable
seat which enables easy, smooth and noiseless back and forth sliding movement of the
seat.
[0008] It is yet another object of the invention to provide a bench with a laterally movable
seat having an overall compact arrangement and an increased sitting surface.
[0009] The above objects are achieved by providing a bench with a laterally movable seat
as defined in claim 1. Various preferred embodiments of the invention are specified
by the dependent claims.
Brief description of the drawings
[0010] The present invention will now be described, by way of examples, with reference to
the accompanying drawings, in which:
Fig. 1 is a perspective bottom view of a preferred embodiment of the bench according
to the invention.
Fig. 2 is a top plan view of a seat supporting plate of the bench according to the
invention.
Fig. 3A is a combined side view and cross-sectional view of the seat supporting plate
of the bench according to the invention with the cross-sectional view being taken
along the line B-B shown in Fig 2.
Fig. 3B is a combined side view and cross-sectional view of the roller mechanism of
the bench according to the invention with the cross-sectional view being taken along
the line B-B shown in Fig 2.
Fig. 3C is a combined side view and cross-sectional view of the seat movement mechanism
of the bench according to the invention, illustrating the mutual arrangement of the
seat supporting plate and a roller mechanism of the bench when assembled, with the
cross-sectional view being taken along the line B-B shown in Fig 2.
Fig. 4 is a bottom view of the roller mechanism of the bench according to the invention.
Fig. 5 is a perspective bottom view of the seat movement mechanism of the bench in
a central position of the seat.
Figs. 6A and 6B are combined side view and sectional view of the bench according to
the invention with the movable seat residing in a central position and a shifted position,
respectively.
[0011] In the following description, the relative terms like "upper", "lower", "above",
"below", "left", "right", etc. are used for a bench standing on the floor, in front
of a user, and only serve better understanding the arrangement and the operation of
the parts of the bench according to the invention. However, such terms should not
be interpreted as any limitation of the scope of the invention.
[0012] Referring to Fig. 1, the bench of the present invention comprises a supporting frame
60, as a stationary part of the bench, configured to rest on a floor, and a laterally
movable seat unit 3, as a movable part of the bench, arranged on a top portion of
the supporting frame 60. The movable seat unit 3 is capable of laterally moving back
and forth with respect to the supporting frame 60 along a horizontal straight line
defined as a moving direction of the moving seat unit 3. The movable seat unit 3 can
be laterally shifted to the left and to the right, from its central position. Preferably,
the lateral end positions of the seat unit 3 are at the same distance from its central
position, and this distance is preferably in the range of 10 to 40 cm in both directions.
[0013] The fixed supporting frame 60 comprises a base structure 61 and a vertical supporting
pillar 62 attached thereto. A roller mechanism is secured on the top of the supporting
pillar 62.
[0014] The movable seat unit 3 comprises a seat supporting plate 31, also shown in Fig.
2 separately, and a seat portion 32, which is attached to the seat supporting plate
31 and comprises a seat cushion 33. The movable seat unit 3 is mounted on the roller
mechanism.
[0015] As shown in Fig. 4, the roller mechanism comprises a roller supporting plate 2 that
may be formed, for example, as a rectangular plate with a longitudinal axis of symmetry
parallel to the moving direction
m. A plurality of rollers 21, 22, 23, 24 are rotatably mounted on the roller supporting
plate 2.
[0016] As shown in Fig. 3A, the seat supporting plate 31 is provided with guiding surfaces
41, 42, 43, 44 (see Figs. 3A and 5) for the rollers 21, 22, 23, 24 of the roller mechanism
for linearly guiding the movable seat unit 3 with respect to the stationary roller
supporting plate 2. Forming the guiding surfaces 41, 42, 43, 44 on the movable seat
unit 3 results in a compact seat configuration with an increased seating surface as
compared to the movable seats of the prior art.
[0017] As shown in Fig 3C, the seat supporting plate 31 is provided on one of its longitudinal
edges with locking means 6 for locking the movable seat unit 3 in a central position
with respect to the supporting pillar 62 of the fixed supporting frame 60 (shown in
Fig. 1).
[0018] As shown in Figs. 3A and 3C, the seat supporting plate 31 comprises first guiding
surfaces 41 extending in parallel to the moving direction
m and facing downwards, second guiding surfaces 42 extending in parallel to the first
guiding surfaces 41 and facing upwards, a third guiding surface 43 extending in parallel
to the moving direction
m and oriented orthogonally to the first and second guiding surfaces 41, 42 and facing
to a first lateral direction orthogonal to the moving direction
m (e.g. forwards), and a fourth guiding surface 44 extending in parallel to the third
guiding surface 43 and facing in a second lateral direction opposite to said first
lateral direction (e.g. backwards). In a preferred embodiment of the bench of the
invention, the first and second guiding surfaces 41, 42 are arranged along the longitudinal
edges of the seat supporting plate 31, whereas the third and fourth guiding surfaces
43, 44 are arranged in a middle region of the seat supporting plate 31.
[0019] As further shown in Figs. 3A and 3C, the seat supporting plate 31 may comprise a
top plate 311 and longitudinal lower flanges 312 extending in the moving direction
m. The top plate 311 may be a one-piece folded plate with four folded flanges projecting
downwardly from each edge of the top plate 311. In this preferred embodiment, the
first guiding surfaces 41 are formed by longitudinal stripe areas of the bottom side
of the top plate 311, adjacent to the longitudinal edges of the rectangular top plate
311. Furthermore, the second guiding surfaces 42 are formed by the top side of the
lower flanges 312. It is preferred that the distance between the plane of the first
guiding surfaces 41 and the plane of the second guiding surfaces 42 is adjustable
by changing the vertical position of the lower flanges 312 with respect to the top
plate 311 for a fine tuning of the frictional force between the guiding surfaces and
the associated rollers. The vertical position of the lower flanges 312 may be changed,
for example, by the screws 316 arranged on the downwardly projecting side surfaces
of the top plate 311.
[0020] As shown in particular in Figs. 3A and 5, a rail 313 is secured to the lower surface
of the top plate 311 so that two opposite longitudinal lateral surfaces of the rail
313 are parallel to the moving direction
m of the seat unit 3, wherein said lateral surfaces of the rail 313 define the third
guiding surface 43 and the fourth guiding surface 44, respectively.
[0021] As best illustrated in Figs. 3C and 5, the seat supporting plate 31 is in contact
with a plurality of rollers of the roller mechanism of the stationary supporting frame.
The rollers include a first group of rollers 21 rotatably mounted on the roller supporting
plate 3 with horizontal axes and bearing against the first guiding surfaces 41 of
the seat supporting plate 31 from below. The rollers further include a second group
of rollers 22 rotatably mounted on the roller supporting plate 31 with horizontal
axes and bearing, from above, against the second guiding surfaces 42 formed by the
top surfaces of the longitudinal lower flanges 312. The rollers further include a
third group of rollers 23 rotatably mounted on the roller supporting plate 31 with
vertical axes and bearing against the third guiding surface 43 defined by one lateral
surface of the rail 313, and a fourth group of rollers 24 rotatably mounted on the
roller supporting plate 31 with vertical axes and bearing against the fourth guiding
surface 44 defined by the other lateral surface of the rail 313 facing in an opposite
direction relative to said first lateral surface.
[0022] As also shown in Figs. 3C and 5, the seat supporting plate 31 is preferably provided
with a locking means 6 arranged at the center of its longitudinal edge on either the
front side or on the back side of the bench. The locking means 6 is configured to
secure the movable seat unit 3 to the supporting pillar to prevent the seat unit 3
from laterally moving with respect to the supporting frame of the bench. The locking
means 6 may include any mechanism suitable for fixing the seat unit 3 relative to
the underlying supporting frame.
[0023] Fig. 4 illustrates the arrangement of the rollers 21, 22, 23, 24 on the roller supporting
plate 2 in a preferred embodiment of the bench according to the invention. As shown
in Fig. 4, the roller supporting plate 2 may be formed as a rectangular plate longitudinally
extending in the moving direction
m of the movable seat unit. The first group of rollers 21 preferably consists of multiple
pairs of coaxial rollers arranged at the longitudinal end portions of the roller supporting
plate 2. The second group of rollers 22 preferably consists of single rollers arranged
at the longitudinal end portions of the roller supporting plate 2, near each pair
of said first rollers 21.
[0024] As best shown in Fig. 3C, the axes of the rollers 21 of the first group and the axes
of the rollers 22 of the second group are vertically offset with respect to each other.
Thus, a functional gap 25 is provided between the second rollers 22 and the associated
first guiding surfaces 41 (shown in Fig. 3A).
[0025] Reverting to Fig. 4, the third and the fourth rollers 23 and 24 consist of single
rollers, preferably also arranged at the longitudinal end portions of the roller supporting
plate 2, at both lateral sides of the rail 313 as also shown in Fig. 3C.
[0026] As it can be seen in Figs. 4 and 5, at both transversal edges of the roller supporting
plate 2, there are shock-absorbers 5, each having a front surface facing in the moving
direction
m of the seat unit. The shock-absorbers 5 are arranged so that in an outermost lateral
position of the seat unit, they bear against the inner lateral surface of the downwardly
folded transversal edge of the seat supporting plate 31. Preferably, the shock-absorbers
5 may be made of an elastic material for damping the force of collision of the seat
supporting plate 31 to the roller supporting plate 2 during use.
[0027] In one embodiment, the shock-absorbers 5 may comprise a pneumatic piston with an
elastic head. In another embodiment, each of the shock-absorbers 5 may comprise a
magnet, and the seat supporting plate 31 may comprise respective counter-magnets having
the same polarity and arranged in line with the magnets of the roller supporting plate
2. The shock-absorbers 5 are used to reduce or eliminate the noise of collision between
the roller supporting plate 2 and the seat supporting plate 31, and further allow
a progressive deceleration of the movable seat unit when it is approaching one of
its outermost position.
[0028] The operation of the bench according to the invention will be described below with
reference to the drawings. In an idle state of the bench, the locking mechanism 6
is activated and thus the movable seat unit 3 is fixed in a central position. Once
the locking mechanism 6 is released, the seat unit 3 can be moved by the user (or
the artist, for example a pianist) from the central position in the lateral moving
direction
m, namely to the left or to the right, back and forth. Due to the roller mechanism
described above, the user can easily displace the movable seat unit 3 in either direction
along the straight moving direction
m of the seat unit 3.
[0029] During motion of the seat unit 3, the third and fourth rollers 23, 24 and the guiding
rail 313 co-operate, by virtue of their mutual arrangement, to produce a linear movement
of the seat unit 3 without any play in a horizontal direction perpendicular to the
moving direction
m. Similarly, the first and second rollers 21, 22 running on the first and second guiding
surfaces 41, 42 also co-operate, by virtue of their mutual arrangement, to produce
a linear movement of the seat unit 3 without any play in the vertical direction and
also preventing the seat unit 3 from tilting.
[0030] When the user is sitting on the bench, the weight of the user applied on the seat
unit 3 is distributed over the first rollers 21, which have a load-bearing function
by supporting the seat supporting plate 31 from below along the first guiding surfaces
41. In the central resting position, as shown in Fig. 6A, the roller supporting plate
2 is located exactly or substantially under the user sitting on the seat unit 3.
[0031] When the seat unit 3 is not in the central position, but in a shifted position as
shown in Fig. 6B, the second rollers 22 prevent the seat unit 31 from tilting along
the moving direction
m. This may be the case when the user moves the seat unit 3 to one of its outermost
positions to reach an extremity of a worktable or an instrument's (e.g. piano) keyboard.
[0032] It is noted that although in the above description, the bench of the invention was
described as comprising a roller mechanism formed of rollers and respective guiding
surfaces, it is obvious for those skilled in the art that instead of rollers, other
rolling means, like wheels, may equally be used without departing the scope of the
invention.
[0033] Furthermore, it is noted that the number and the arrangement of the rollers may vary
depending on the expected load distribution of the movable seat.
[0034] It should be also noted that the guiding surfaces for the rollers may be formed in
or on the seat supporting plate in many other ways, provided that they comply with
the geometrical restrictions defined above.
1. A bench with a laterally movable seat, in particular a piano bench, comprising:
- a stationary supporting frame (60) configured to rest on a floor,
- a seat unit (3) arranged on a top portion of the supporting frame (60), the seat
unit (3) being configured to be movable with respect to the supporting frame (60)
by means of rollers (21, 22, 23, 24) along a horizontal straight line defined as a
moving direction (m),
characterized in that
- the rollers (21, 22, 23, 24) are rotatably mounted on the supporting frame (60),
- the movable seat unit (3) is provided with first guiding surfaces (41) extending
parallel to the moving direction (m) of the seat unit (3), wherein a first group of
said rollers (21) mounted on the supporting frame (60) with horizontal axes of rotation
are arranged to bear against said first guiding surfaces (41) of the seat unit (3)
from below,
- the movable seat unit (3) is further provided with second guiding surfaces (42)
extending parallel to the moving direction (m) of the seat unit (3) and also parallel
to said first guiding surfaces (41), wherein a second group of rollers (22) mounted
on the supporting frame (60) with horizontal axes of rotation are arranged to bear
against said second guiding surfaces (42) of the seat unit (3) from above,
- the movable seat unit (3) is further provided with a third guiding surface (43)
extending parallel to the moving direction (m) of the seat unit (3) and oriented orthogonally
to said first and second guiding surfaces (41, 42), wherein a third group of rollers
(23) mounted on the supporting frame (60) with vertical axes of rotation are arranged
to bear against said third guiding surface (43) of the seat unit (3) in a first horizontal
direction orthogonal to said moving direction (m),
- the movable seat unit (3) is further provided with a fourth guiding surface (44)
extending in parallel to said third guiding surface (43), wherein a fourth group of
rollers (24) mounted on the supporting frame (60) with vertical axes of rotation are
arranged to bear against said fourth guiding surface (44) in a second horizontal direction
opposite to said first horizontal direction.
2. The bench according to claim 1, characterized in that said first guiding surfaces (41) are provided on a bottom of a top plate (311) of
a seat supporting plate (31) of the seat unit (3), and the second guiding surfaces
(42) are provided on an upper surface of a lower flange (312) of said seat supporting
plate (31).
3. The bench according to claim 1 or 2, characterized in that said third guiding surface (43) and said fourth guiding surface (44) are defined
by two opposite lateral surfaces of a rail (313) mounted on a bottom of a top plate
(311) of a seat supporting plate (31) of said seat unit (3), said rail (313) longitudinally
extending parallel to the moving direction (m) of the seat unit (3).
4. The bench according to any one of the preceding claims, characterized in that the supporting frame (60) is provided with shock-absorbers (5) mounted on the roller
supporting plate (2) at its longitudinal end portions.
5. The bench according to any one of the preceding claims, characterized in that the seat supporting plate (31) is provided with locking means (6).
6. The bench according to claim 5, characterized in that the locking means (6) is either on the front side or on the back side of the seat
supporting plate (31) of the bench.