Background of the invention

[0001] The invention relates to temporary sealing of doors and in particular to a sealing inner frame.

[0002] External or internal doors sometimes need to be sealed to prevent dust or air in general from moving into and out of the prem ises. A prior art method for this is to cover with tape the gaps between the frame and the door and those between the door sill and the door or the floor and the door. The door becomes sealed and, when sealing is no longer needed, the tapes can be removed and the door used as usually.

[0003] A problem with the above arrangement is that using the door is laborious and news tapes must be applied every time after the door has been opened or somebody has gone in or out. Moreover, depending on the tape used and on how long the sealing is needed, the tape may leave marks on the door or the frame that are difficult to remove, or the tape may become detached over time, in which case the door is no longer sealed.

Brief description of the invention

[0004] It is thus an object of the invention to develop a device so as to solve the above-mentioned problems. The object of the invention is achieved by a device which is characterized by what is disclosed in the independent claim. Preferred embodiments of the invention are disclosed in the dependent claims.

[0005] The invention is based on the idea of installing an inner frame provided with seals to a door opening defined by a door frame. The inner frame is provided with at least two separate seals. A first seal seals a gap between the inner frame and the door frame, and a second seal a gap between the closed door and the inner frame,

[0006] An advantage of the device of the invention is that the inner frame is quick to install in place and the door may be used almost as usually because the door opening becomes sealed every time the door is closed.

Brief description of the figures

[0007] The invention will now be described in more detail by means of preferred embodiments and with reference to the accompanying drawings, in which: Figure 1 shows an inner frame according to an em bodiment installed in a door opening;

Figure 2 shows a detail of an installed inner frame according to an em bodiment.

Detailed description of the invention

[0008] With reference to Figure 1 . there is disclosed an inner frame 20 installed in a door opening defined by a door frame 10 and a door sill 1 2. The inner frame may be manufactured mostly of wood, plastic, metal or two or more combinations or m ixtures of said materials. The inner frame is either dimensioned according to the size of the door opening or, preferably, arranged in a modular form , in which case the width or height of the inner frame may be increased or decreased by adding or removing parts. The smallest possible inner frame size may be one that is installable into the smallest standard-size door frame, in which case the inner frame size may be increased, when necessary, with the modules to correspond to larger door frames.

[0009] According to an em bodiment, vertical structures operate telescopically, i. e. two partly nested, overlapping or adjacent structures, e. g. rectangular or square profiles, form one inner frame side that may be extended or shortened by changing the m utual position of these partly nested structures. The telescopic structure may be spring-loaded so that the vertical structures com prise at least one spring, the tensioning of which causes a spring force that is arranged to press the horizontal structures of the inner frame 20 against the door frame 10 when the inner frame is in the door opening formed by the door frame.

[0010] According to an em bodiment, the horizontal structures operate telescopically, i.e. two partly nested, overlapping or adjacent structures, e.g. rectangular or square profiles, form one inner frame side that may be extended or shortened by changing the m utual position of these partly nested structures. The telescopic structure may be spring-loaded so that the horizontal structures comprise at least one spring, the tensioning of which causes a spring force that is arranged to press the vertical structures of the inner frame 20 against the door frame 10 when the inner frame is in the door opening formed by the door frame.

[001 1 ] According to an em bodiment, both the vertical and the horizontal structures operate telescopically, i. e. two partly nested, overlapping or adjacent structures, e.g. rectangular or square profiles, form one inner frame side that may be extended or shortened by changing the mutual position of these partly nested structures. The telescopic structures may be spring-loaded so that both the vertical and the horizontal structures each comprise at least one spring, the tensioning of which causes a spring force that is arranged to press the horizontal and vertical structures of the inner frame 20 against the door frame 10 and the door sill 12 or the floor when the inner frame is inside the door opening formed by the door frame.

[0012] According to an embodiment, the height and/or width of the inner frame 20 may be adjusted by changing the length of the vertical and/or horizontal structures. The vertical and/or horizontal structures are each formed of two or more parts that are arranged to move and to be locked in relation to one another, which allows the length of the vertical and/or horizontal structures to be changed by moving the parts in relation to one another and by locking the parts to a length that allows a desired inner frame dimensioning to be achieved.

[0013] Figure 2 shows a cross-section of a detail of an inner frame 20 according to an embodiment and its seals 22. 24, 26 installed in association with the door frame 10 and a closed door 30. According to this embodiment, a vertical structure of the inner frame 20 is provided with two first seals 22, 24 arranged to press against the door frame and one second seal 26 arranged to press against the door. According to another embodiment, one, three or four first seals are used. According to another embodiment, two, three or four second seals are used.

[0014] The first seals 22, 24 of Figure 2 are arranged to press against the door frame 10 e.g. by the effect of the spring force produced by the spring comprised by the horizontal structures of the inner frame 20. The seals are preferably made of an elastic and/or resilient material and/or in the form of a structure that allows the seal to compress when the seals are pressed against the door frame or another structure. The seal material may comprise e.g. plastic, rubber, silicone and/or foamed plastic.

[0015] The second seal 26 of Figure 2 is arranged to press against the door 30 when the door 30 is closed. The seals are preferably of an elastic and/or resilient material and/or in the form of a structure that allows the seal to compress when the door is closed, the door being thus sealed against the inner frame. [0016] According to an em bodiment, the inner frame 20 com prises at least one third seal arranged to the undersurface of the lowest horizontal structure of the inner frame, the third seal thus sealing a gap between the inner frame and the floor or one between the inner frame and the door sill. According to an embodiment, the third seal is not part of the inner frame but a separate seal that is placed under the inner frame before the inner frame is installed in place. The seals are preferably of an elastic and/or resilient material and/or in the form of a structure that allows the seal to compress due to the effect of the own weight of the inner frame 20.

[0017] The heights of the door opening defined by the door frame vary from some m illimetres to some centimetres depending on the m anufacturer, time of manufacture, model, mounting and other sim ilar reasons. It is not reasonable to anticipate such a small, almost random, deviation . by preparing several inner frames of slightly different heights. The problem may be solved by one inner frame and one additional seal arranged to be placed between the inner frame and the door frame head. The height of the inner frame may be arranged such that as far as height is concerned, the inner frame may be installed to most, almost all or all commonly used prior art door frames. In other words, the inner frame is thus dimensioned according to the smallest door frame height. When higher door frames are used, an additional seal is placed on the inner frame, between the inner frame and the door frame head, for example after the inner frame has been installed in place into the door opening defined by the door frame. The additional seal may be e.g. a piece of foamed plastic equal in width with the door opening and one to five centimetres in height to allow the opening left above the inner frame to be sealed. Each standard door opening width may have a separate additional seal, or, alternatively, a single wide additional seal may be used, in which case an excess part remaining in the case of a narrow door opening is folded double onto the inner frame or left hanging loose.

[0018] According to an embodiment, the gap created above the inner frame because of varying door opening heights is not provided with a seal but with a filter. The filter to be used is preferably of an elastic and/or compressible filter material, which allows the filter to be made wider and higher than the gap, the filter being slightly squeezed when placed into the gap. The filter blocks the gap tight, allowing air to pass through the filter but preventing fine particles from travelling through the filter. In that case the filter allows air pressure to become balanced on both sides of the door opening provided with the inner frame also when the door is closed. The filtering capacity of the filter may be chosen according to the dem ands set by the site, yet a P3-filter that meets the requirements of even the most demanding prem ises is preferred. According to an em bodiment, an elastic and/or com pressible P3-category fi lter comprises or is manufactured of a cellulose-based material,

[0019] It will be apparent to a person skilled in the art that as technology advances, the basic idea of the invention may be implemented in many different ways. The invention and its embodiments are thus not restricted to the exam ples described above but may vary within the scope of the claims.