Background and Summary of the Invention
The present invention concerns a door frame, especially but not exclusively meant for fireproof doors, said door frame covering the edge sides of a door opening in a wall and consisting of two frame portions assembled from plate profiles bent substantially in L-form, said frame portions being mounted in said door opening in such a way that one leg of each plate profile engages the outside of said wall round said door opening and the other profile leg thereof extends into said door opening substantially parallel with the edge side thereof and overlaps the corresponding profile leg of the other frame portion inside of said door opening.
A number of different ways and means for the mounting of door frames of this kind have already been suggested. It is thus already known to provide one of the frame portions with tabs protruding into the door opening and being nailed fast against the edge side thereof during the mounting. The other frame portion is thereafter usually joined to the frame portion attached in the door opening by means of rivets which are inserted through holes provided during the mounting, or through a pair of holes, which are aligned with each other during the mounting. It is also known to arrange a toothed projection on one of the frame portions, which during the mounting is brought into engagement with a fastening member of the other frame portion to retain said frame portions at a distance from each other determined by the thickness of said wall.
Another prior art device is shown in U.S. Pat. No. 1,180,726. In such a device, two frame members are drawn together by a threaded rod connection, however, the cooperating portions of the threaded rod connection are telescoped together. This provides positive guiding of the frame members, and they therefore cannot adapt to deviations in the parallelism of the outer surfaces of the wall to which they are to be attached. Also, no overlap is provided between the legs extending into the door opening, but merely an overlap between a door abutment surface attached to one leg and the other leg, the other leg also having no portion of the threaded rod connection formed inwardly thereof for preventing damage thereto upon inward movement thereof (toward the wall). Thus it will be seen that the door frame according to the present invention does not have many of the disadvantages of the prior art structures, such as being relatively expensive and/or not being able to adapt to deviations in wall surface parallelism, etc.
It is the primary object of the present invention to provide an improved door frame construction, especially for fireproof doors. This and other objects of the invention will become clear from an inspection of the detailed description of the invention and from the appended claims.
Brief Description of the Drawings
Two embodiments of the invention will now be described with reference to the attached drawing, on which
FIG. 1 in cross section shows a frame side of a door frame according to the invention of the principally simplest form thereof and
FIG. 2 in a similar view a development of the inventive concept, the frame portions being shown in dash-dot lines before the mounting is completed.
Detailed Description of the Invention
As stated in the aforesaid the door frame according to the present invention is meant to cover the side edge 1 of a door opening in a wall 2. The door frame consists of two frame portions 3 and 4 assembled of profile plates bent to a substantially L-shaped form. In the mounted position one profile leg 3a and 4a of each frame portion 3 and 4, respectively, strongly engages the adjacent outer surface 5 and 6, respectively, of the wall round the door opening. If desired, the edges of said profile legs 3a and 4a can be bent inwardly at right angles to the profile leg and comprise an edge flange parallel to said leg, which flange is pressed into engagement with the outer surface of the wall 2 when the door frame is mounted. The other profile legs 3b and 4b of the L-shaped profile plates are intended to extend into the door opening substantially parallel with the edge side 1 thereof and to overlap each other within the door opening. One of said profile legs may in a known manner be bent in such a way as to form an abutment 7 for a door leaf. The door frame described above is formed in a conventional manner.
According to the invention a number of rods 8 with one of their ends are rigidly connected to one of the frame portions on the inside of the profile leg engaging the outer surface 5 or 6 of the wall 2, i.e., to the profile leg 4a of the frame portion 4 as shown on the drawing. Said rods are spaced round the door frame, for instance at least two rods being arranged on each one of the vertical frame sides. The rods 8 extend at right angles to the profile leg 4a and the free ends thereof thus facing the corresponding profile leg 3a of the cooperating frame portion 3. A bore extends from the free end of each rod 8 a substantial distance into same and said bore is provided with internal threads.
A hole is provided in the other frame portion 3 in the corresponding profile leg 3a thereof opposite each rod 8. Said holes are arranged to accommodate rotatable rods 9, preferably in the form of threaded bolts having hexagonal heads 10 or similar means on the outside of said profile leg 3a. As shown at 20 in FIG. 1, the rotatable threaded rod 9 may be universally swingably mounted in the profile leg 3a to assist in adapting the structure to a wall 2 having outer surfaces 5, 6 thereof of different parallelism. The bolt heads 10 have curved bottom portions 21 which cooperate with correspondingly curved depressions 22 formed in profile leg 3a in order to provide for the universal swingable mounting of the rotatable rods 9 in the profile leg 3a.
When the door frame is to be mounted, the frame portions 3 and 4 are inserted in proper positions into said door opening and the bolts 9 are brought into engagement with the threaded holes of the rods 8. By rotation of the bolts 9 the frame portions 3 and 4 are pressed against each other and the profile legs 3a and 4a are forced into strong engagement against the opposite outer surfaces 5 and 6, respectively, of the wall 2, so that the door frame is immovably retained in the door opening.
To facilitate this mounting the rigid rods 8 are preferably arranged on the frame portion, whose profile leg 4b extending into the door opening is situated at the greatest distance from the edge side 1 of the door opening. The rod 8 is thereby placed at such a distance from the profile leg 4b that a gap 11 is formed therebetween. The gap 11 shall have such a width that it can accommodate the profile leg 3b of the other frame portion 3, which enters into the door opening, and guide said profile leg during the mounting. These features provide for adaptation of the structure to accommodate a wall 2 having outer surfaces 5, 6 of different parallelism. Also, although the gap 11 is large enough to accommodate the profile leg 3b and allow movement thereof to adapt to wall outer surfaces 5, 6 of different parallelism, it is not so large that the profile leg 3b may be damaged by forced movement toward the wall 2 without first abutting the fixed rod 8.
The embodiment of FIG. 2 corresponds in all essentials with the one described in the aforesaid and the means already described have therefore been provided with the same reference numerals and will not again be described in detail.
In the embodiment of FIG. 2 one end of a bar 12 of flat iron is attached to the root end of the rigid rod 8 and extends as an arch inwardly towards the edgeside 1 of the door opening and thereafter outwardly towards the rotatable rod 9 of the outer frame portion 3. The free end 14 of the bar 12 is bifurcated and the prongs thereof are situated on opposite sides of said rotatable rod or bolt 9. Said bifurcated end 14 abuts against a shoulder 15 which preferably is arranged on said rotatable rod 9, and to ensure proper abutment the outer end of said prongs are bent in the direction of said edge side 1.
In the unmounted condition the curvature of said bar 12 is relatively small, i.e., the radius of curvature thereof is great as shown by a thick dash-dot line 12a in FIG. 2. When the frame portions 3, 4 during the mounting are displaced towards each other upon rotation of the bolt 9, the shoulder 15 is also displaced to approach the point of attachment of the bar 12, so that said bar 12 is more strongly arched, i.e., is given a smaller radius of curvature, as shown in full lines on FIG. 2. The apex portion 16 of said bar 12 is thereby pressed into abutment against the adjacent edge side 1 of the door opening and the door frame is thereby maintained fixed against displacement in the plane of the wall and the profile legs 3b and 4b overlapping each other are strongly pressed together, so that no gap is present therebetween.
According to FIG. 2 the shoulder 15 is formed by a nut which is screwed on to said bolt 9. Before commencing the mounting said nut may be moved to a suitable position along the bolt 9 so that sufficiently strong arching of the bar 12 is obtained to press same against said edge side 1. The nut 15 is preferably locked in the desired position by means known per se.
By forming a door frame as described above, a very simple and inexpensive construction is provided that will automatically adapt to walls having outer surfaces of different parallelism, fulfilling the objects of the present invention. While the invention has been herein shown and described in what is presently conceived to be the most practical and preferred embodiments of the invention, it will be apparent to those of ordinary skill in the art that many modifications may be made thereof within the scope of the invention, which scope is to be accorded that broadest interpretation of the appended claims so as to encompass all equivalent structures and devices.