[0001] The invention relates to an inspection door for closing an inspection opening provided
in a flagged covering or casing, said door including a flat removable cover plate
made from sheet steel and adapted to be covered with flags, and a frame adapted to
be flagged and carrying permanent magnets for supporting said cover plate.
[0002] An inspection door of this kind is known from DE-A-27 56 124. Such known inspection
door has the frame made of profile bars each having one profile leg to be flagged
and another profile leg projecting into the gap between the flags of the flagged cover
plate and the flagging surrounding the inspection opening, and said frame has off-set
sheet stripes projecting into the frame opening and carrying said permanent magnets
which are in the form of cylindrical magnets having external threads and being screwed
into associated tab holes of said off-set sheet stripes.
[0003] Every paviour knows the difficulties in mounting such or similar inspection doors
so as to achieve a properly flush closure of the inspection opening with the flags
of the inspection door being properly integrated into the gap pattern of the surrounding
flagging. However, this is difficult with the just mentioned prior art inspection
door and with other commercial inspection doors as well. The profile legs projecting
into the gap between the inspection door and the surrounding flagging reduces the
possible extent of correction of the flags covering the cover plate, on the one hand,
and requires to provide gaps of excessive width in the region of the inspection door,
on the other hand, and, furthermore, the proper adjustment of the position of the
four magnets will often be achieved only after multiple sequences of trial and troublesome
removal of the cover plate failing to take a properly flush position. Despite of this,
manufacturing of said prior art inspection door is expensive and requires numerous
parts, and proper mounting is time-consuming and difficult.
[0004] Therefore, it is the object of the present invention to provide an inspection door
of the kind in question so as to allow for quick and easy mounting independently of
the thickness of the flags and to be convenient and inexpensive in respect to manufacture,
and so as to form, when mounted, an unconspicuous closure of an inspection opening,
which closure being properly integrated into the gap pattern of the surrounding flagging
and allowing to be opened, when necessary, but which otherwise cannot be easily recognized
and allows for an air- and water-tight closure of the inspection opening.
[0005] In view of this object, the invention resides in an inspection door for closing an
inspection opening provided in a flagged covering or casing, said door including a
flat removable cover plate made from sheet steel and adapted to be covered with flags,
and a frame adapted to be flagged and carrying permanent magnets for supporting said
cover plate, characterized in that said frame has a plane front surface and is made
as a sheet construction of sheet material having the same thickness as said cover
plate and consisting of at least two sheet stripes arranged at two opposite edges
of said cover plate, and in that said magnets are mounted so as to support said cover
plate flush with the plane front surface of said frame.
[0006] The inspection door according to the invention lends itself especially for use in
laying flags in a thin layer of cement and, because of its easy mounting, is cut out
specifically for do-it-yourself workers who can make a proper flagging without specific
technical knowledge and without special mechanical skill.
[0007] The inspection door according to the invention has the frame and the cover plate
lying in a common plane, that is flush with each other so that mounting is performed
simply by inserting the frame in the region of the edges of the inspection opening
flush with the substrate to be flagged, and the frame and the cover plate can then
be covered with flags, whereby a flush position of the flagged cover plate with the
surrounding flagging can be achieved without any special adjustment and totally independently
of the respective thickness of the flags. Due to the absence of any webs of the frame
projecting into the gap between the cover plate and the surrounding flagging, the
cover plate together with its flagging can be properly integrated into the flag pattern,
and permanently elastic gap filler can then be injected into the gap and, when the
inspection door needs to be opened, can be scraped out and renewed thereafter. Thus,
the mounted inspection door is air- and water-tight.
[0008] The inspection door according to the invention can be manufactured in a very easy
and inexpensive manner because, except for the magnets and, if need be, their mountings
attached to the backside of the frame, it consists only of flat sheet material.
[0009] The frame can consist of two sheet stripes to be mounted at opposite sides of the
inspection opening, said two stripes being rigidly connected to each other by two
transverse bars attached to their backsides. This allows for easy manufacture of the
frame without punching out any large opening and, simultaneously, allows for easy
mounting of the inspection door.
[0010] Alternatively, the frame can be formed by a sheet plate having a central opening
corresponding to the size of said cover plate. In case of large piece numbers, this
alternative constitutes the best method of manufacture and results in a frame construction
which is rigid in itself.
[0011] Preferably, said magnets each are attached to the backside of the frame in such a
manner that their support surfaces for said cover plate are flush with the backside
of the frame and project beyond the inner edges of the frame into the frame opening.
[0012] Said magnets can be made as flat magnets, each of them being attached with one edge
thereof to the backside of the frame, or being arranged diagonally at one corner of
said frame opening. Preferably, said magnets are attached to the backside of the frame
by adhesive.
[0013] Alternatively, each of said magnets can be mounted in a recess of a bar or of a lug
attached to the backside of said frame and crossing said frame opening or extending
into said frame opening. Each of said magnets can be adjustably mounted in a tab hole
of said bar or lug.
[0014] In a preferred embodiment of the invention, two opposite sheet stripes of said frame
have their edge portions adjacent to said frame opening off-set backwards by the amount
of the sheet thickness so as to form additional support surfaces for said cover plate,
said additional support surfaces extending substantially along the full length of
the respective two opposite edges of the cover plate, thus rendering installation
of the inspection door even more easy and improving proper and flush support of the
cover plate. In this embodiment, the magnets can be mounted in recesses of said off-set
edge portions.
[0015] Some examples of embodiments of the invention are shown in the accompanying drawings
and are described hereinafter in more detail.
[0016] In the drawings,
fig. 1 is a cross-sectional view of an inspection door according to the invention
mounted in a flagged covering,
fig. 2 is a top view of an embodiment of an inspection door according to the invention,
fig. 3 is a top view of an alternative embodiment of an inspection door according
to the invention,
figs. 4, 5 and 6 are top views of the frame of the inspection door with varipus alteratives
of mounting the magnets, and
fig. 7 a further embodiment of an inspection door according to the invention.
[0017] Fig. 1 shows an inspection door 3 constructed according to the invention and mounted
at a flagged wall across an inspection opening 2, the inspection door consisting of
a frame 4, of permanent magnets 5 attached thereto, and of a cover plate 3. Frame
4 is, using a bed of mortar 7 for instance, mounted into wall 1 at the border of inspection
opening 2 flush with wall surface 1a to be flagged. Permanent magnets 5 in the form
of flat magnet bodies each have its edge portion attached to the backside of the frame,
by means of adhesive for example, and they project beyond the inner edges of the frame
into the inspection opening, each magnet's support surface 5a for supporting the cover
plate 6 being flush with the backside of-the frame. Frame 4 and cover plate 6 are
both made from sheet steel of the same thickness, thus rendering the front surfaces
of frame 4 and cover plate 6 flush with each other and also with outer wall surface
1a when cover plate 6 is inserted. After flagging with a thin layer of cement 8, flags
9 attached to the wall around inspection opening 2 and flags 10 attached to cover
plate 6 ly flush with each other.
[0018] The gaps between flags 10 of the cover plate and the surrounding flags 9 have a permanently
elastic gap filler 11 injected therein which, when the inspection door needs to be
opened, will be scraped out and renewed thereafter. Opening of the inspection door
can easily be performed using a suction apparatus as known per se.
[0019] Fig. 2 shows a top view of the inspection door according to fig. 1 in a smaller scale,
wherein the flagging is indicated in dotted lines only. Frame 4 consists of a sheet
plate in which a central opening 4a is punched out for receiving cover plate 6 with
some clearance. Four magnets 5 are each diagonally mounted at the four corners of
frame opening 4a.
[0020] Fig. 3 shows a modified embodiment of the inspection door in which the frame is made
from two sheet stripes 41 and 42 extending at opposite sides of cover plate 6. Each
of said two sheet stripes has two magnets 5 attached to its backside at its edge region
extending towards the inspection opening. Said two sheet stripes 41 and 42 constituting
said frame can be connected to each other by two transverse bars 43 shown in dotted
lines, which bars each are attached to the backside of said two sheet stripes 41 and
42, such as by spot welding, to joint them to a rigid frame construction allowing
for easy mounting.
[0021] Figs. 4, 5 and 6 show various alternatives of mounting the magnets to the frame.
[0022] The embodiment according to fig. 4 has short bars 52 each extending diagonally across
the corner region of the frame opening and attached to the backside of frame 4, with
a magnet 51 being inserted into a recess of bar 52 and attached thereto.
[0023] Fig. 5 shows a modified arrangement in which lugs 55 are attached to the backside
of frame 4, each of said lugs carrying one magnet 51 inserted into a recess thereof.
[0024] Fig. 6 shows a frame similar to that of fig. 3 consisting of two sheet stripes 41
and 42 connected to each other by two transverse bars 52 carrying two magnets 51 each
inserted into recesses thereof.
[0025] Fig. 7 shows a top view of a preferred embodiment of the frame 4 of the inspection
door wherein the frame consists of two opposite sheet stripes 45 and 46 having their
edge portions 45a, 46a adjacent to frame opening 4a off-set backwards by the amount
of the sheet thickness (see cross-sectional profile P of said sheet stripes drawn
into the top view of sheet stripe 46), and of two plane sheet stripes 47 and 48 attached
by spot welding to the front surfaces of said off-set edge portions 45a and 46a of
said first-mentioned sheet stripes 45 and 46. The magnets 51 may be mounted in recesses
of said off-set edge portions 45a and 46a or may be attached to the frame in any other
way.
1. An inspection door for closing an inspection opening provided in a flagged covering
or casing, said door including a flat removable cover plate (6) made from sheet steel
and adapted to be covered with flags, and a frame (4) adapted to be flagged and carrying
permanent magnets (5) for supporting said cover plate (6), characterized in that said
frame (4) has a plane front surface and is made as a sheet construction of sheet material
having the same thickness as said cover plate and consisting of at least two sheet
stripes (41, 42) arranged at two opposite edges of said cover plate, and in that said
magnets (5) are mounted so as to support said cover plate (6) flush with the plane
front surface of said frame (4).
2. An inspection door according to claim 1, characterized in that said two sheet stripes
(41, 42) of said frame (4) are rigidly connected to each other by means of two transverse
bars (43) attached to the backside thereof.
3. An inspection door according to claim 1, characterized in that said frame (4) is
formed by a sheet plate having a central opening (4a) corresponding to the size of
said cover plate (6).
4. An inspection door according to any of claims 1 to 3, characterized in that said
magnets (5) are each attached to the backside of the frame in such a manner that their
support surfaces (5a) for said cover plate (6) are flush with the backside of the
frame and project beyond the inner edges of the frame into the frame opening.
5. An inspection door according to claim 4, characterized in that said magnets (5)
are made as flat magnets, each of them being attached along an edge thereof to the
backside of said frame.
6. An inspection door according to claims 3 and 4, characterized in that said magnets
(5) are made as flat magnets each being arranged diagonally at one corner of said
frame opening (4a).
7. An inspection door according to any of claims 1 to 3, characterized in that each
of said magnets (51) is mounted in a recess of a bar (52) attached to the backside
of said frame and crossing said frame opening (4a).
8. An inspection door according to any of claims 1 to 3, characterized in that each
of said magnets (51) is mounted in a recess of a lug (55) attached to the backside
of said frame and extending into said frame opening (4a).
9. An inspection door according to any of claims 1 to 3, characterized in that two
opposite sheet stripes (45, 46) of said frame (4) have their edge portions (45a, 46a)
adjacent to said frame opening (4a) off-set backwards by the amount of the sheet thickness
so as to form additional support surfaces for said cover plate (6).
10. An inspection door according to claim 9, characterized in that said magnets (51)
are mounted in recesses of said off-set edge portions (45a, 46a).