Note: Descriptions are shown in the official language in which they were submitted.
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Driving device for support column
Background
The present invention relates to a driving device for an articulated support
column, like a telescopic column for supporting a desk, the driving device
having
a central longitudinal axis and comprising;
¨ a drivable rope drum for winding a rope, which driveable rope drum
is supported by a drum support frame,
¨ a pulley for reversing a rope, which pulley is supported by a pulley
bracket,
Such a driving device is known from DE10253362 Al which discloses a
height adjusting system for a telescopic legs of a table. The system has a
drum
attached to a support column. This is connected by an endless cable to a
pulley which
adjusts the height. DE10253362 has for its object to provide a height
adjustment for
table legs, which height adjustment is largely free of play and synchronous.
This
object is achieved in that the distance between the drum and the pulley may be
adjusted and in that at least one end of the cable is attached by a spring to
the fixed
part of the leg or a related column.
The solution taught by DE10253362 is complex and has a high part count which
is required to enable adjustment the distance between the drum and the pulley.
In
addition, this adjustment complicates installation and maintenance. There is
room for
improvement.
Summary of the invention
The invention aims to provide a driving device for an articulated support
column, which driving device has less play.
Another object of the invention is to improve a driving device for an
articulated
support column, in that the number of parts is reduced.
Yet another object of the invention is to provide an alternative driving
device for
an articulated support column is provided wherein a problem with such a known
driving device is at least partly solved.
According to a first aspect of the invention this is realized with a driving
device
for an articulated support column, like a column for supporting a desk, the
driving
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device having a central longitudinal axis and comprising;
¨ a drivable rope drum for winding a rope, which driveable rope drum is
supported by a drum support frame,
¨ a pulley for reversing a rope, which pulley is supported by a pulley
bracket,
¨ a first elongate frame member extending along the central longitudinal
axis of the driving device and having one end coupled with the drum
support frame and an opposite end coupled with the pulley bracket for
spaced arrangement of the drum support frame and the pulley bracket,
and wherein the elongate frame member is configured for tensioning a
rope between the rope drum and the pulley,
¨ an endless rope coupled with the drum and pulley, which rope is
wound a number of rope turns around the drum and turned around the
pulley,
¨ a second elongate frame member moveably arranged with respect to
the first elongate frame member, and coupled with the rope for moving
with the rope over a second elongate frame member stroke between a
retracted and an extended position,
wherein the rope comprises a drum coupling section which is permanently
coupled with the drum such that the drum coupling section is tangentially
fixed with respect to the drum.
The rope comprising a drum coupling section coupled with the drum such that
the drum coupling section is tangentially fixed with respect to the drum
assures that
play is avoided and that synchronizing between columns provided with these
driving
devices is enabled.
Configured for tension in connection with the first elongate frame member here
means the that the first elongate frame member has such strength that the rope
may be
prestressed.
The rope being endless has to be understood that lines of forces are closed.
These lines of forces may pass through a coupling piece that couples the two
ends of
said rope. It will be understood that any suitable means like a line,
(braided) steel
wire, snare, may be used in the driving device.
The drum coupling section of the rope being permanently coupled with the
drum means the section can not detach from its associated groove in the drum
when
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turning the drum.
The drum coupling section is coupled with the drum through a coupling piece,
and the coupling piece extends radially into the drum. This enables fast
coupling of
the drum coupling section and the drum while still assuring tangential
constraint of
said drum coupling section with respect to the drum.
In an embodiment of the driving device, the drum coupling section is part of a
central rope turn. Central here refers to the centre of the drum where the
central rope
turn is arranged. This drum coupling section being part of a central rope
turn, allows
to minimize the width of the drum at a given second elongate frame member
stroke.
The number of rope turns determines the second elongate frame member stroke.
In an embodiment of the driving device, the number of rope turns is such that
when the second elongate frame member takes its retracted position or its
extended
position, always at least one adjacent rope turn extends along each side of
the drum
coupling section of the rope. In this manner the drum coupling section is
supported at
both sides which aids in the coupling thereof with the drum.
In an embodiment of the driving device, the rope drum is rotatable around a
drum
axis, the pulley is rotatable around a pulley axis, and, seen along the
central
longitudinal axis of the driving device, the drum axis and the pulley axis
enclose an
angle a such that the pulley bridges about the width of the drum. This
facilitate
smooth running of the drum and pulley and avoids internal friction because the
obliquity of both the rope sections, between the pulley and the drum, with
respect to
the central longitudinal axis of the driving device, is minimized.
In an embodiment of the driving device, the angle a is about 450
.
In an embodiment of the driving device, the number of rope turns covers about
half of the width of the drum.
In an embodiment of the driving device, the rope is prestressed with a rope
force
of about 1000 N.
In an embodiment of the driving device, the first elongate frame member and
the
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second elongate frame member extend parallel next to each other.
In an embodiment of the driving device, the first elongate frame member and
the
second elongate frame member are arranged at a mutual distance by a single
spacing frame.
In an embodiment of the driving device, the spacing frame is fixedly coupled
with
the first elongate frame member proximate the pulley bracket and wherein the
spacing frame is slideably coupled with the second elongate frame member.
In an embodiment of the driving device, the second elongate frame member is
coupled with the rope at its end which faces towards the drum frame and
wherein
the second elongate frame member comprises a guiding element for engaging
said column in a sliding manner, wherein the guiding element is arranged
proximate said end.
In an embodiment, the driving device comprises coupling means for coupling
the driving device to an articulated column.
The invention further relates to a device comprising one or more of the
characterising features described in the description and/or shown in the
attached
drawings.
The invention further relates to a method comprising one or more of the
characterising features described in the description and/or shown in the
attached
drawings.
The various aspects discussed in this patent can be combined in order to
provide
additional advantages.
Description of the drawings
The invention will be further elucidated referring to an preferred embodiment
shown
in the drawings wherein shown in:
Fig. 1 in side view a driving device according to the invention;
fig. 2 a front view of a detail of the driving device according to fig. 1;
fig. 3 a side view of the detail of fig. 2;
fig. 4 a perspective view of another detail of the driving device according to
fig. 1;
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fig. 5 a perspective view of another detail of fig. 1; and
fig. 6 a perspective view of another detail of fig. 1.
Detailed description of embodiments
The embodiment will now be described in more detail referring to all figures 1-
6. In
the figures there is shown a driving device 1 for an articulated support
column, like a
column for supporting a desk. The shown driving device 1 is in use installed
in a
height adjustable support column for e.g. a desk. Both the support column and
the
desk are not shown. The driving device 1 has a central longitudinal axis 5.
The
driving device 1 is length adjustable and drives a support column along the
central
longitudinal axis 5.
The driving device 1 comprises a drivable rope drum 2 for winding a rope 6.
Driveable means that the driving device may be manually driven or driven by a
electric motor. Usually, a number of driving devices are driven in parallel.
The
driveable rope drum 2 is supported by a drum support frame 3 in any suitable
manner.
The driving device 1 comprises a pulley 4 for reversing the rope 6. The pulley
is
supported by a pulley bracket 7 in any suitable manner.
The rope drum 2 is rotatable around a drum axis 14. The pulley 4 is rotatable
around a pulley axis 15. The drum 2 and the pulley are mutually arranged such
that
seen along the central longitudinal axis 5 of the driving device 1, the drum
axis 14
and the pulley axis 15 enclose an angle. The enclosed angle a is configured
such that
the pulley 4 extends, or bridges, at least about the total width of the number
of rope
turns 9 provided on the drum 2. In this case, the enclosed angle a is about
450
.
The driving device 1 comprises a first elongate frame member 8. The elongate
frame member 8 extends along the central longitudinal axis 5 of the driving
device 1.
One end 21 of the elongate frame 8 is coupled with the drum support frame 3 in
any
suitable manner like welding. Likewise, the opposite end 22 of the elongate
frame 8
is coupled with the pulley bracket 7. In this manner the drum support frame 3
and the
pulley bracket 7 are arranged at a mutual distance determined by the elongate
frame
member 8. The elongate frame member 8 is configured such that the rope 6 may
be
prestressed with a rope force of about 1000 N.
The driving device 1 comprises an endless rope 6 coupled with the drum 2 and
pulley 4. The rope is wound a number of rope turns 9 around the drum 2 and
turned
around the pulley 4, here turned once around the pulley 4. The number of rope
turns 9
determines the second elongate frame member stroke. The number of rope turns 9
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covers about half of the width w of the drum 2. More precisely, the number of
free
grooves 23 of the drum 2 also determine the second elongate frame member
stroke.
The rope 6 comprises a drum coupling section 11. The drum coupling section 11
is permanently coupled with the drum 2 such that the drum coupling section 11
is at
least tangentially fixed with respect to the drum 2. In this manner, and in
conjunction
with the prestressed rope 6, the driving device 1 is able to drive a column
(not shown)
in a virtually backlash free way. It is conceivable that the drum coupling
section 11 is
also radially fixed with respect to the drum 2. The drum coupling section is
part of a
central rope turn 13. When the second elongate frame member 10 takes its
retracted
position or its extended position, always at least one adjacent rope turn 9
extends
along the drum coupling section 11 of the rope 6 to provide lateral support to
the
drum coupling section 11.
The drum coupling section 11 is coupled with the drum 2 through a coupling
piece 12. The coupling piece 12 extends radially into the drum 2. The coupling
piece
12 may have a rectangular shape as shown in fig 2a, however it will be clear
that any
suitable shape will suffice for the coupling piece 12.
The driving device 1 comprises a second elongate frame member 10. The second
elongate frame member 10 is moveably arranged with respect to the first
elongate
frame member 8. The second elongate frame member 10 is moveable along the
central longitudinal axis 5 of the driving device 1. The first elongate frame
member 8
and the second elongate frame member 10 extend parallel next to each other.
The first
elongate frame member 8 and the second elongate frame member 10 are arranged
at a
mutual distance by a single spacing frame 16 as best shown in fig. 4. In this
case, the
spacing frame 16 is fixedly coupled with the first elongate frame member 8
proximate the pulley bracket 7 as shown in fig. 5. The spacing frame 16 is
slideably
coupled with the second elongate frame member 10.
The second elongate frame member 10 is coupled with the rope 6 for moving
with the rope 6 over a second elongate frame member stroke between a retracted
and
an extended position. In fig. 1 the second elongate frame member 10 is shown
in a
position between a retracted and an extended position. The second elongate
frame
member 10 is coupled with the rope 6 at its end which faces towards the drum
frame
3 as best shown in fig. 3. The second elongate frame member 10 comprises a
guiding
element 24 for engaging said column (not shown) in a sliding manner. The
guiding
element 24 is arranged proximate said end which faces towards the drum frame
3.
The driving device 1 comprises coupling means 19, 25 for coupling the driving
device 1 to an articulated column (not shown). Any suitable coupling means
will
suffice.
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It will also be obvious after the above description and drawings are included
to
illustrate some embodiments of the invention, and not to limit the scope of
protection.
Starting from this disclosure, many more embodiments will be evident to a
skilled
person which are within the scope of protection and the essence of this
invention and
which are obvious combinations of prior art techniques and the disclosure of
this
patent.
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