Improvements in Gratings for Covering Openings or Channels in Floors and Pavements.
Year: 1894

page_text: Date of Application, 17th May, 1894
Complete Specification Left, 16th Feb., 1895-Accepted, 23rd Mar., 1895
PROVISIONAL SPECIFICATION.
Improvements in Gratings for Covering Openings or Channels in
Floors and Pavements.
1, PETER KNOBEL, of Flums, Switzerland, Manufacturer, do hereby declare
the nature of this invention to be as follows:-
This invention has reference to a construction of grating intended to cover
openings or channels in floors and pavements, such for example as ohannels located
below the floor level and containing heating pipes extending from a central heating
apparatus, light-shafts or areas in front of underground windows and other openings
intended to be traversed by pedestrians, but which cannot be closed by a con-
tinuous or non-openworked cover, because of its being necessary to allow a medium
such as light or heat to pass freely therethrough.
The bars of a grating for such purposes must consequently be capable of
supporting a cousiderable weight, and must also contract or obscure the total
area of the opening as little as possible so as to allow of the passage of the said
media.
Now this invention has reference to an improved construction of grating in
which both these qualities are combined in an advantageous manner. According
thereto the grating is constructed of bars of special cross-section each formed by
beading or bending the longitudinal edges or side portions of a bar of thin flat
metal such as iron or steel so as to form at each side of such bar a longitudinal
channel or hollow ridge. These bars are arranged on edge in position in the
grating, the form of cross section adopted, imparting to them great strength against
flexure in all directions. Consequently for a given load and lateral flexure, these
bars can be made thinner than bars of simple rectangular cross section such as have
heretofore been employed. Consequently a grating composed of bars of the special
form mentioned will possess greater stiffness in all directions and will cause a
considerably less contraction of the total area of an opening in the floor or
pavement to which it is applied, than a grating composed of bars of rectangular
cross section.
Fig. 1 is an end view partly in section, showing one construction of grating
according to this invention.
Fig. 2 is an end view illustrating the application of such a grating to an opening
in a pavement which is shown in section.
a are the bars of special cross section formed with longitudinal channels or
hollow ridges a' at their edges, these bars being arranged and kept at suitable
intervals apart, to form a grating, by interposed distance-pieces, consisting for
instance of short tubes b, the bars and distance-pieces being securely connected
together by means of rods or bolts e provided at one end with a head c' and at the
other end with a screw nut c, and extend transversely through the bars and the
distance-pieces as shown. The number of rods or bolts c employed will depend
upon the size of the grating.
The slots or openings between the bars of the grating have a curved or wary.
form but have throughout their length the same cross sectional area which is
determined by the length of the distance pieces b.
In Fig. 2 the grating is shown applied to an opening in the form of a channel
extending below the pavement and of the kind ordinarily employed for the

page_text: reception of pipes d for conveying heated water or air from a central heating
apparatus.
Dated this 17th day of May 1894
Improvements in Gratings for Covering Openings or Channels in
Floors and Pavements.
I, PETER KNOBEL of Flums, Switzerland, Manufacturer, do hereby declare
the nature of this invention and in what manner the same is to be performed to
be particularly described and ascertained in and by the following statement :-
This invention has reference to a construction of grating intended to cover
openings or channels in floors and pavements such for example as channels located
below the floor level and containing lieating pipes extending from a central heating
apparatus, light shafts or areas in front of underground windows and other openings
intended to be traversed by pedestrians but which cannot be closed by a con-
tinuous or non-openworked cover, because of its being necessary to allow a medium
such as light or heat to pass freely therethrough.
The bars of a grating for such purposes must consequently be capable of
supporting a considerable weight, and must also contract or obscure the total
area of the opening as little as possible so as to allow of the passage of the said
media.
Now this invention has reference to an improved construction of grating in
which both these qualities are combined in an advantageous manner. According
thereto the grating is constructed of bars of special cross-section each formed by
beading or bending the longitudinal edges or side portions of a bar of thin flat
metal such as iron or steel so as to form at each side of such bar a longitudinal
channel or hollow ridge. These bars are arranged on edge in position in the
grating, the form of cross section adopted imparting to them great strength against
flexure in all directions. Consequently for a given load and lateral flexure, these
bars can be made thinner than bars of simple rectangular cross section such as have
heretofore been employed. Consequently a grating composed of bars of the special
form mentioned will possess greater stiffness in all directions and will cause a
considerably less contraction of the total area of an opening in the floor or
pavement to which it is applied, than a grating composed of bars of rectangular
cross section.
Referring to the drawings left with my Provisional Specification,
Fig. 1 is an end view partly in section, showing one construction of grating
according to this invention, and
Fig. 2 is an end view illustrating the application of such a grating to an opening
in a pavement which is shown in section.
a are the bars of special cross section formed with longitudinal channels or
hollow ridges a at their edges, these bars being arranged and kept at suitable
intervals apart to form a grating, by interposed distance-pieces, consisting for
instance of short tubes b, the bars and distance pieces being securely connected
together by means of rods or bolts e provided at one end with a head c¹ and at the
other end with a screw nut and extending transversely through the bars and
distance-pieces as shown. The number of rods or bolts c employed will depend
upon the size of the grating.
The slots or openings between the bars of the grating have a curved or wavy

page_text: form, but have throughout their length the same cross sectional area which is
determined by the length of the distance pieces b.
In Fig. 2 the grating is shown applied to an opening in the form of a channel
extending below the pavement and of the kind ordinarily employed for the
reception of pipes d for conveying heated water or air from a central heating
apparatus.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
A grating for covering openings or channels in floors and pavements, comprising
metal bars spaced apart sideways and vertically in the direction of their width and
each of a cross sectional form having edges or side portions which are inclined
towards each other and are of undulating or corrugated form substantially as
described and shown.
Dated this 16th day of February 1895.
For the Applicant,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.