Note: Descriptions are shown in the official language in which they were submitted.
CA 02340846 2001-03-15
SOUND INSULATION DEVICE FOR SYSTEMS WITH A MOVEABLE
ELEMENT
The invention relates to a sound insulation device for
mechanical systems with a moveable, particularly with a
laterally slideable element in accordance with the
preamble of patent claim 1.
In order to close off and/or divide rooms use is
frequently made of sliding doors which are connected to a
running mechanism guided in a rail (Fig. 4 as an example
shows a running mechanism 6 and a rail 5).
The rail is usually mounted on the ceiling or on a
sidewall. These devices often cause disturbing noise which
depends on the used running mechanism and rail, the
usually significant weight of the sliding doors and the
structure of the wall.
In case that for example a lecture is given in a
conference room, then the sounds caused by moving sliding
doors or sidewalk in neighbouring rooms may be considered
disturbing in the conference room. Said noises are also
disturbing in private apartments particularly during night
time, when the prevailing noise level besides is reduced
to a minimum. Modern closing systems are sometimes
equipped with running mechanisms, which are driven by
electro motors. Vibrations caused by the electro motors
may also appear disturbing.
The present invention is therefore based on the object of
providing a sound insulation device for systems which
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comprise at least one moveable, particularly laterally
slideable element.
This object is achieved by the measures specified in claim
1. Advantageous embodiments of the invention are specified
in further claims.
The sound insulation device which is designed for a
mechanical system comprising at least one moveable element
prevents the transmission of disturbing sound waves from
the mechanical system to a neighbouring system. Mechanical
systems of this kind consist for example of a rail in
which a running mechanism is slideable mounted. The rail
is connected by means of the sound insulation device for
example to the ceiling of a room or to the top cover of a
wardrobe.
The sound insulation device which in conjunction with the
mechanical system forms an oscillating system is designed
in such a way that the resonant frequency of the
oscillating system lies outside the frequency band in
which an undamped system causes disturbing sound waves.
Sound waves outside the resonant frequency area are
reflected in the sound insulation device on two reflection
zones which are arranged in series.
The sound insulation device comprises preferably two angle
elements to be connected to a mounting body with each of
the angle elements being connected through a sound soft
elastic layer with a middle part on which the mechanical
system is suspended. The angle elements and the middle
part are preferably designed in such a way that by said
elements a pressure is applied to the sound soft layer in
order to prevent the sound soft layer, which is attached
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by means of an adhesive, from getting detached from the
middle part and the corresponding angle element.
In a preferred embodiment the complete detachment of the
middle part from the angle elements is further prevented,
in case of a fire when the sound soft layer is melted.
In the following, the invention is explained in more
detail with reference to a drawing, in which:
Fig. 1 shows an inventive sound insulation device 1 in
a preferred embodiment,
Fig. 2 shows the sound insulation device 1 according to
Fig. 1 connected to a rail 5 which is designed
to guide a running mechanism,
Fig. 3 shows a second sound insulation device 100,
which on one side is connected to a rail 5 and
on the other side is mounted on a carrier plate
200,
Fig. 4 shows a third sound insulation device 101
integrated in a ceiling respective in a top
cover of a wardrobe 201 and connected to a rail
5 and
Fig. 5 shows the sound insulation device 1 according to
Fig. 1 equipped with holding strips.
Fig. 1 shows an inventive sound insulation device 1
serving for the attachment of a mechanical system
comprising a moveable, particularly a laterally slideable
element. As shown for example in Fig. 4 the mechanical
system consists of a rail 5, which is connected by means
of the sound insulation device 1 to a mounting body, and
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of a running mechanism 6 , guided in said rail 5 and
slideable holding a sliding door or a sliding element.
The sound insulation device 1, by which oscillations
caused by the moveable element are strongly damped and
partially reflected, consists of a sound hard middle part
3 preferably made of metal and two sound hard angle
elements 2a, 2b preferably made of metal.
The middle part 3 comprises a base plate 31 connectable to
the mechanical system, e.g. to the rail 5, which base
plate 31 connects two wing elements 32a, 32b with each
other. Each of the wing elements 32a, 32b is connected
over a sound soft, elastic layer 4a respective 4b with a
side part 22a respective 22b of an angle element 2a
respective 2b. The angle elements 2a, 2b comprise besides
the side part 22a respective 22b a base part 21a, 21b
which is connectable to the mounting body.
The installed sound insulation device 1 expands a
mechanical system connected thereto to an oscillation
system with at least one resonance frequency, which lies
below the frequency range of disturbing sound signals
which may occur when a moveable element is laterally
slided. The oscillation system is adjusted through
selection of constitution and size of the two sound soft
layers 4a, 4b which consist preferably of a high quality
rubber material and which are attached by means of an
adhesive to the corresponding wing element 32a respective
32b and to the corresponding side part 22a respective 22b.
The resonant frequency of the oscillation system results
from the square root of the spring constant of the sound
insulation device 1 divided by the square root of the
weight of the system connected thereto. In a preferred
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embodiment the surface pressure on the sound soft layers
4a, 4b is selected in the range from 2 kg/cm2 to 4 kg/cm2.
Due to the selection of a sound soft material for the
layers 4a, 4b two reflection zones arise in the transition
zones between the sound soft layer 4a respective 4b and
the sound hard wing element 32a respective 32b and the
side part 22a respective 22b. Sound waves lying outside
the resonant area of the oscillation system are reflected
on the reflection zones so that the sound insulation
device 1 provides a doubled acoustical insulation of the
mechanical system.
The percentage of the reflection is dependant on the ratio
of the sound hardness respective the acoustical impedances
of the materials adjoining the reflection zones, the
wavelength and the density of the sound.
Substances with a high acoustical impedance are called
sound hard. Substances with a low acoustical impedance are
called sound soft. The acoustical impedance respective the
sound hardness results by multiplying the density of the
material and the velocity of propagation of the sound
within this material.
The wing elements 32a, 32b connected to the middle part 3
and the side parts 22a, 22b connected to the angle
elements 2a, 2b are preferably inclined towards each other
in such a way that the sound soft layers 4a, 4b during a
movement of the middle part 3 in the direction of the
gravitational force are simultaneously stressed in view of
shearing and pressure.
Low frequency oscillations with high amplitude may occur
through shearing movements. With a pressure simultaneously
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applied the sound soft material remains in the
predetermined form and in addition a detachment of the
layers 4a, 4b (e. g. by shearing) is prevented. The device
shown in Fig. 1 therefore allows the use of elastic
materials with a low acoustical impedance. The relevant
dimensions (heights h, breadths b, lengths 1 and
thicknesses d) of the device elements marked with indices
are drawn in Fig. 2. It can be seen that the middle part 3
and the angle elements 2a, 2b in direction of the
gravitational force are shifted relative to each other in
such a way that during the occurrence of oscillations the
middle part 3 does not touch the mounting body and the
angle elements 2a, 2b do not touch the rail 5.
The wing elements 32a, 32b and the side parts 22a
respective 22b are in direction of the gravitational force
strongly inclined (in the shown embodiment by 30°
respective 35°), so that when a load is applied on the
sound insulation device 1 consequently high force vectors
arise through which the sound soft layers 4a, 4b are
simultaneously stressed in view of shearing and pressure.
With the inclination respective a mutual overlapping of
the side parts 22a respective 22b and the wing elements
32a, 32b it is achieved, that the wing elements 32a, 32b
of the middle part 3 are supported by the side parts 22a
respective 22b of the angle elements 2a, 2b when the sound
soft layers 4a, 4b are molten. In such a way the
mechanical system which may comprise a moveable part
remains even in a case of fire connected to the mounting
body.
A detachment of sound soft layers 4a, 4b during load
condition may further be prevented by selecting a
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preferred contour of the layers 4a, 4b at their end parts.
Preferably a contour converging towards the supporting
surfaces is selected so that under load an even
distribution of mechanical tension results along the sound
soft layers 4a, 4b. The material of the sound soft layers
4a, 4b lies preferably in such a way on the wing elements
32a, 32b connected to the middle part 3 and on the side
parts 22a, 22b connected to the angle elements 2a, 2b that
the end parts of the sound soft layers 4a, 4b follow the
form of a cylinder thereby getting continuously thinner
towards the end. For easier handling during production,
where preferably a vulcanising process is applied, the
rubber layers 4a, 4b are delimited by bodies having the
from of a cylinder (see Fig. 1, circles kl and k2).
Inventive sound insulation devices 1 may be used to
install mechanical systems of different kinds to a
mounting body. Due to the small dimensions, the sound
insulation devices 1 may advantageously be used for the
installation of rails 5 (see Fig. 2), along which a
running mechanism 6 is guided carrying a sliding door or a
sliding separation element (see Fig. 4).
The sound insulation device 1 may be installed with simple
means. The base plate 31 of the middle part 3 and the base
part 21a, 21b of each angle element 2a, 2b preferably
comprise openings 32a, 23b; 33, through which mounting
screws can be inserted, which are connected to the
mounting body and to the rail 5.
The middle part 3 of the sound insulation device 1 shown
in Fig. 1 is installed opened towards the top. It is
however also possible to install the middle part 3
installed opened downwards. A middle part 3 installed
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opened downwards could have the form of a rail 5 as the
one shown in Fig. 2.
Fig. 3 shows a second sound insulation device 100, which
is connected on the one side to a rail 5 and on the other
side to a carrier plate 200. The sound insulation device
100 comprises a sound soft element 400, in which a tube
400 with a thread is encapsulated, into which a mounting
screw 7 designed for holding the rail 5 is turned. Between
the sound soft element 400, the carrier plate 200 and the
tube 300, in the present case also on the rail 5 adjoining
the sound soft element 400, arise reflection zones which
reduce the transmission of sound.
Fig. 4 shows a third sound insulation device 101
integrated in a ceiling respective in a top cover of a
wardrobe 201 and connected to a rail 5. The sound
insulation device 101 comprises a sound soft element 401,
which embraces a tube 301 comprising a flange 302.
The rail 5 is connected by means of a mounting screw 7 to
the tube 301. The sound soft element 401 comprises a
flange 404 with a bordering edge 403 and cylindrical body
402, in which for the insertion of the tube 301 an opening
is provided. In the ceiling respective in the top cover
201 of the wardrobe an opening 202 is provided suitable
for receiving the sound soft element 401.
Between the sound soft element 401 and the ceiling 201 is
a further elastic layer 405 arranged, through which the
rail 5 is decoupled from the ceiling 201 respective from
the top cover 201 of the wardrobe. Between the sound soft
element 401 and the ceiling 201 respective the top cover
201 of the wardrobe and the tube 301 result again
reflection zones, which reduce the sound transmission.
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Fig. 5 shows the sound insulation device 1 according to
Fig, l, in which the sides of middle part 3 and the angle
elements 2a, 2b directed towards each other are equipped
with holding strips 34. The holding strips 34 which may
have a height in the range from 1/10 mm to 5 mm and which
may lead straight or inclined sloping from bottom to top
are used for holding the elastic layers 4a, 4b in place
and/or for the form fitting connection of the middle part
3 and the angle elements 2a, 2b in case that the elastic
layer 4a respective 4b loses adhesive connection, thereby
providing an increased safety level. The holding strips 34
may also be shorter or comprise one or more breaks.
