Mechanical drawings of manhole covers exposed in this website (identification particular details
and "dimensions' key" as well as the criterions which make the expoed manhole covers related to other kinds of manhole covers,
or are derived from them, than those shown in drawings), have already been exposed at Fairs and Exhibitions for technical products.
The conditions listed below were also exposed :
General specifications
All interchangeable Lids and Frames (having equal rated fitting diameter and verge-edge/rabbet
height) may be manufactured as to match each other.
Circular fitting (C.F.) lids may be redesigned to fit ( match) square or other kind of frames.
C.F. lids which are designed to match any square frame, may be redesigned
to match other kind of square frame ( as face-side pattern, or dimension).
C.F. lids, which are part from square (exterior top shape) manhole covers, shall not be redesigned
to match circular (exterior top shape) frames, while, the lids designed for circular (top-shape) frames
may be redesigned to match square (top shape), or other kind of frames.
Lids' overall diameter or fitting edge height, frames' height and their overall dimensions,
fitting rated diameter or rabbet's height, may not be considered as identification details
as long as they are not included in the "dimension's key" context.
Backsides designs have their own "dimensions' key".
Conicities, Lids' edge and frames' backing bearings, and clear opening values
are not part of the "dimensions' key". Therefore, there may be resized for technical reasons.
If conicities' values are changed, all top surface dimensions of frames and lids will be preserved.
The conditions specified on the drawings shall be followed first, then the general conditions and specifications.
Racord radii between Lid's plate below surfaces
will be considered equal with those between below plate surface
and fitting edge interior surface.
The fitting edge's bevel-cants may be replaced in curvature radii. The fitting edge's height, the curvature radii between the Lid's plate backside
and the reinforcing ribs may be replaced with other values.
Curvatures (rounding-radii) may be also applied wherever technical rerasons require.
Perimetral bevel-cant and curvature radii are not part of the "dimension's key", therefore they may be resized.
FlatLids specifications
- FlatLids are lids designed with the upper surface on the theoretical
plane that contains the upper or lowest level of (flutings or other) face's pattern.
- Flat-face lids, or lids which have "flat face" phrase in their name,
are mainly designed to be further redesigned on the face-side,
or to be completed with any other existing face pattern.
- FlatLids having a specification to be matched only with certain patterns,
shall be completed only with those ones.
- FlatLids without any matching specifications, (and) called "for general use" may match
any existing face pattern, or may be also redesigned as grates (are).
- If a FlatLid is redesigned as a grate, only the reinforcing ribs will be preserved as shape and position, but the lid's plate thickness "t" may be changed.
- If a FlatLid design already contains holes, the holes' shape and position shall be preserved
if the holes' shape and position dimensions are indicated on the drawing.
- However such kinds of hole FlatLids may be redesigned as Grates or as hole-lids too, adding other holes
but preserving the existing ones, following the specifications mentioned above.
The added holes will be larger and have other shapes if posible, and shall not be positioned between the existing holes, or inside the space delimited by them.
- The redesign of FlatLids does not allow the crossing, removing or position changing of the reinforceing ribs.
[This is a general specification for backsides redesign, but only, as long as there are no other specifications for each Lid design.
If any design has a specification for backside design too, it will be followed.]
- Holes' backside margins shall be at least 5 millimeters far from the nearest reinforceing rib.
- If an opening key access place will be designed, the lid's backside plate may be moved downwards, but not lower then the upper bottom of the ribs
(but in any position of plate's surface).
For FlatLids, the lid's cross section or cross details will be considered together depending on the backside view design used in manufacturing.
Resizing conditions
- The resizing of Lids' dimensions (whether preserving dimensions' ratio, or not)
is allowed only in the specified interval. Even if the resizing of the lid's dimensions will be done only within this interval, the shapes and number of holes and other face's pattern parts will be preserved.
- The resizing of frames' dimensions may be done only by adding or diminishing equal
values from the diameter or sides' dimensions, and not by ratio resizing.
- Outside of these limits, the dimensions resizing may be considered abusive.
Resizing Lids' backside designs is allowed only for larger dimensions, not for smaller ones.
A lid face design having a certain resizing interval, may match a lid backside design having another resizing interval, if both the Face design that matches the FlatLid's backside
design have a common resizing interval.
Resizing interval for a lid design may have different values for face and backside.
The face-side view drawing will contain the resizing interval for the face-side design; the "flat" section and the backside drawings will contain the resizing interval for the backside.
Inscription conditions
- Trade-mark and loading class, or other inscriptions, shall be mentioned only on the inscriptions reserved place (area), but in any order.
- If the inscription area is on the Lid's or Frame's top level, the inscription letters will be engraved.
- If the inscription surface is below the lid's or frame's top surface level, the letters will be
inbold relief.
- If there is a specification area for large or bold letters, it must be followed.
Any marks will be placed in this area, too.
- If any law allows and the manufacturer wants not to write a trade-mark or sign, the reserved space may be blank.
If the blank space is somehow on any square shaped fluted surface, thes will be continued over the blank space.
Any specifications may be found on drawings, if necessary.
Other specifications
[ Separate designed covers - for face-side design to match a FlatLid - should be applied only for Lids having two levels of face surface only - pattern top level and pattern's flutings bottom level,
(or inscription area). The covers having other face-side pattern levels are designed at all, and do not match the flat cover ]
Any other possible changes on the exposed covers' designs, that are not specified are forbiden.
IN CONCLUSION
The manufacture of grey-cast-iron manhole covers using our mechanical drawings designs is unrestricted as long as the resulted products (or part of them which follow our designs), or the used mechanical drawings (which are part of our designs) are not included in a copyrighted work, and the terms and conditions specified above are followed by the manufacturer.
The "ManholeCoversDesigner" will not shadow and will not sue for the observance
of the conditions exposed above ; all of these are only a warning ...!!
