U.S. patent application number 10/575013 was filed with the patent office on 2008-02-07 for lid for a shaft cover and shaft cover.
This patent application is currently assigned to HYDROTEC Technologies GmbH & Co.KG. Invention is credited to Wilfried Neuber.
Application Number | 20080028688 10/575013 |
Document ID | / |
Family ID | 32748419 |
Filed Date | 2008-02-07 |
United States Patent
Application |
20080028688 |
Kind Code |
A1 |
Neuber; Wilfried |
February 7, 2008 |
Lid for a Shaft Cover and Shaft Cover
Abstract
The invention relates to a lid for a shaft cover, comprising a
cover body (12) and at least one locking means (20) arranged on the
body of the lid (12), said locking means comprising a spring
section (21-24) and an engaging section (26) which can be placed
into contact with one part (36) of the frame (30) and arranged
thereon. The invention is characterised in that the spring section
(21-24) is respectively secured by both ends thereof to the body of
the lid (12), is separated from the body of the lid (12) and the
engaging section (26) is arranged between the two ends of the
spring section (21-24).
Inventors: |
Neuber; Wilfried;
(Delmenhorst, DE) |
Correspondence
Address: |
FITZPATRICK CELLA HARPER & SCINTO
30 ROCKEFELLER PLAZA
NEW YORK
NY
10112
US
|
Assignee: |
HYDROTEC Technologies GmbH &
Co.KG
Wildeshausen
DE
|
Family ID: |
32748419 |
Appl. No.: |
10/575013 |
Filed: |
September 13, 2004 |
PCT Filed: |
September 13, 2004 |
PCT NO: |
PCT/EP04/10195 |
371 Date: |
April 12, 2007 |
Current U.S.
Class: |
52/20 ;
404/25 |
Current CPC
Class: |
E02D 29/1427
20130101 |
Class at
Publication: |
52/20 ;
404/25 |
International
Class: |
E02D 29/14 20060101
E02D029/14 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 9, 2003 |
DE |
203 15 709.5 |
Claims
1. Cover for a manhole top with a cover body (12) and with at least
one locking means (20) arranged on the cover body (12), said
locking means having a spring section (21 through 24) and, arranged
thereon, an engagement section (26) that can be brought into
engagement with a part (36) of a frame (30), characterized in that
the spring section (21 through 24) is attached by each of its two
ends to the cover body (12) and is otherwise separated from the
cover body (12), and the engagement section (26) is arranged
between the two ends of the spring section (21 through 24).
2. Cover according to claim 1, characterized in that the spring
section (21 through 24) extends approximately parallel to the cover
body (12).
3. Cover according to claim 1 or 2, characterized in that the
spring section is designed as an annular body (21 through 24),
which is attached to the cover body (12) by a retaining section
(25) that essentially joins the two ends of the spring section.
4. Cover according to claim 3, characterized in that the annular
body has the approximate shape of a circle.
5. Cover according to claim 4, characterized in that the engagement
section is arranged at a location essentially diametrically
opposite the retaining section.
6. Cover according to claim 3, characterized in that the annular
body (21 through 24) has the approximate shape of an oval with two,
preferably semicircular, curved sections (21, 22) and two
essentially elongated sections (23, 24) connecting these two curved
sections (21, 22) to one another.
7. Cover according to claim 6, characterized in that the retaining
section (25) is located on one elongated section (24), and the
engagement section (26) is located on the other elongated section
(23).
8. Cover according to claim 7, characterized in that the elongated
section (23) bearing the engagement section (26) is recessed
relative to the ends of the curved sections (21, 22) that are
connected by this elongated section (23).
9. Cover according to at least one of the preceding claims,
characterized in that the engagement section (26) has a
wedge-shaped detent section.
10. Cover according to at least one of the preceding claims,
characterized in that the locking means (20) is located on the
underside of the cover body (12).
11. Cover according to at least one of the preceding claims, in
which the cover (10) is provided with stiffening ribs (16),
characterized in that the locking means (20) are located a distance
apart from the stiffening ribs (16) on the cover body (12).
12. Manhole top with a cover (10) according to at least one of the
preceding claims and with a frame (30) for accommodating the cover
(10).
Description
[0001] The invention concerns a cover for a manhole top with a
cover body and with at least one locking means arranged on the
cover body, said locking means having a spring section and,
arranged thereon, an engagement section that can be brought into
engagement with a part of a frame. In addition, the invention
concerns a manhole top with such a cover and with a frame
accommodating said cover.
[0002] Manhole tops with such a locking system, whose engagement
usually takes place in the manner of a detent or catch, are known
and are widely used. As an example, reference is made in this
connection to WO 86/04624, which discloses a self-locking manhole
cover in which the locking means has a resilient arm that has one
end cast to a stiffening rib on the underside of the cover body,
and extends with its other free end to a portion of the
circumference of the cover essentially parallel thereto. A detent
projection that sits at the free end of the resilient arm, at right
angles to its longitudinal extent, is provided as the engagement
section. In order to latch the detent projection in a corresponding
recess in the frame, or to release it therefrom, the resilient arm
is elastically movable at right angles to its longitudinal extent,
the detent projection being appropriately preloaded in the
direction toward the frame by the resilient arm.
[0003] The present invention now proposes to attach the spring
section by each of its two ends to the cover body while keeping it
otherwise separated from the cover body, and to arrange the
engagement section between the two ends of the resilient arm.
[0004] On account of the inventive construction, the spring section
functions in the manner of a leaf spring that is fixed at both
ends. It has become evident in this context that the inventive
construction permits realization of a locking system that functions
with particular effectiveness while at the same time being
especially easy to use.
[0005] Preferably the spring section extends approximately parallel
to the cover body.
[0006] An especially preferred embodiment of the invention is
characterized in that the spring section is designed as an annular
body, which is attached to the cover body by a retaining section
that essentially joins the two ends of the spring section. As a
result of the fact that, in this embodiment, the two ends of the
spring section are essentially closed to form an annular body, the
spring section functions as a dual leaf spring arrangement with two
parallel leaf springs, wherein one half of the annular body,
between whose ends the engagement section is located, performs the
function of the first leaf spring, and the second half of the
annular body, between whose ends the retaining section is located,
performs the function of the second leaf spring. The efficiency of
the spring action can be increased even further by such a
design.
[0007] As a general rule, the annular body can have any shape, as
long as the spring section is curved such that its two ends meet or
are at least arranged adjacent to one another.
[0008] For example, the annular body can have the approximate shape
of a circle, wherein the engagement section is usefully arranged at
a location essentially diametrically opposite the retaining
section.
[0009] Alternatively, however, the annular body can also have the
shape of, e.g., an oval with two, preferably semicircular, curved
sections and two essentially elongated sections connecting these
two curved sections to one another. The reason being that the shape
of such an elongated oval is especially useful for increasing the
spring action. The retaining section should preferably be located
on one elongated section, with the engagement section located on
the other elongated section. The elongated section bearing the
engagement section can preferably be recessed relative to the ends
of the curved sections that are connected by this elongated
section, by which means the annular body can be adapted especially
well to the design circumstances, with regard to the desired spring
action as well as with regard to the space required.
[0010] The engagement section usefully has a wedge-shaped detent
section, by means of which the engagement functions as a catch.
Accordingly, the detent section is provided with at least one
surface inclined in the direction of engagement. In addition, it is
also possible to design a surface inclined in the opposite
direction on the detent section as well, for easier release.
Alternatively or in addition, however, it is also possible to
design the corresponding engagement surfaces on the frame part with
a wedge shape or inclined as angled surfaces.
[0011] The locking means is usually located on the underside of the
cover body.
[0012] When the cover is provided with stiffening ribs, the locking
means should be located on the cover body a distance apart from the
stiffening ribs, by which means an especially space-saving
arrangement of the locking means results.
[0013] Lastly, it should be noted for the sake of completeness that
at least two locking means should usually be provided on the cover,
with said locking means being spaced apart from one another and
usually located opposite one another, and radially opposite one
another in the case of a circular cover.
[0014] A preferred example embodiment of the invention is described
below on the basis of the attached figures. Shown are:
[0015] FIG. 1 a perspective view from below of a cover for a
manhole top;
[0016] FIG. 2 a perspective view from below of an arrangement of
the cover from FIG. 1 on a frame;
[0017] FIG. 2a an enlarged sectional detail view of FIG. 2;
[0018] FIG. 3 a cross-section through the arrangement of cover and
frame shown in FIG. 2; and
[0019] FIG. 3a an enlarged sectional detail view of FIG. 3.
[0020] FIG. 1 shows a perspective view from below of a disk-shaped
cover 10, which forms a manhole top in combination with a suitable
annular frame that is described in detail below.
[0021] The cover 10, of which the underside can be seen in FIG. 1,
has a disk-shaped cover body 12 whose perimeter is bordered on its
underside by a circumferential web 14 that projects downward. This
circumferential web 14 serves as a support when the cover 10 is
used in a frame, as described below. In addition, the cover body 12
is provided on its underside with stiffening ribs 16 extending
radially.
[0022] Located on the underside of the cover body 12 at each of two
radially opposite locations, located in each case between two
adjacent ribs 16 and the circumferential web 12, is a locking means
20 that is provided on its outer side, facing the circumferential
web 14, with a detent projection 26 that faces radially
outward.
[0023] FIGS. 2 and 3 also show the associated annular frame 30 on
which the cover 10 rests and which forms, together with the cover
10, the manhole top. As can be seen from FIG. 3a in particular, the
frame 30 in the example embodiment shown has on its inner side an
inward-projecting circumferential support surface 32 that lies in a
plane that extends essentially horizontally in the installed state
of the frame 30. With the cover 10 placed in the frame 30, the
cover 10 rests with its downward-projecting circumferential web 14
on this annular support surface 32 of the frame 30, so that the
support surface 32 serves as a support for the cover 10 on the
frame 30.
[0024] When placed in the frame 30, the cover 10 is locked to the
frame 30. The aforementioned locking means 20 are attached to the
underside of the cover body 12 for this purpose.
[0025] The precise structure of the locking means 20, in
particular, is evident in FIG. 2a. In the example embodiment shown,
each locking means 20 has a closed annular body that lies in a
plane extending essentially parallel to the disk-shaped cover body
12. In the example embodiment shown, the annular body is comprised
of a closed strip-shaped element that extends essentially at right
angles to the disk-shaped cover body 12. As is further evident from
FIG. 2 in particular, the annular body consists of two
approximately U-shaped curved sections 21 and 22 and two
essentially elongated sections 23 and 24. The two elongated
sections 23 and 24 connect the curved sections 21 and 22 together,
by which means the annular body thus produced has an approximately
oval shape.
[0026] The annular connecting means 20 is cast to the underside of
the cover body 12 through a retaining section 25 at the elongated
section 24 facing the center of the cover body 12, while the rest
of the annular connecting means 20 is separated from and spaced
apart from the underside of the cover body 12.
[0027] The detent projection 26 sits in a radially outward-facing
position on the edge of the elongated section 23 that faces the
edge of the cover 10. Here, the detent projection 26 is located at
a point on the annular body of the locking means 20 essentially
radially opposite the retaining section 25. As is further evident
from FIG. 2a in particular, the locking means 20 has a bilaterally
symmetrical shape whose axis of symmetry (not shown) extends
essentially radially. The retaining section 25 and the detent
projection 26 also lie on this imaginary axis of symmetry.
[0028] It is further evident from FIG. 2a in particular that the
elongated section 23 that bears the detent projection 26 is
recessed slightly with respect to the ends of the curved sections
21, 22 that are joined together by this elongated section 23.
Therefore, in the example embodiment shown, the shape of the
locking means 20 also slightly resembles the outline of a
butterfly.
[0029] The section of the oval locking means 20 that is separated
from the cover body 12, and is comprised of the two curved sections
12, 22, the elongated section 23, and the outer edge sections of
the elongated section 24, produces a spring action after the manner
of an arrangement of two parallel leaf springs in the radial
direction with respect to the stationary retaining section 25. In
this way, the detent projection 26 is elastically preloaded in the
radial direction.
[0030] Since the annular locking means 20 in the example embodiment
shown is formed as a single piece on the cover body 12 with the aid
of the retaining section 25, the locking means 20 is made of the
same material as the cover body 12. This is usually a cast
material, with which the desired spring action of the locking means
20 can be achieved easily due to the above-described design.
[0031] As is evident from FIG. 3a in particular, locking of the
cover 10 onto the frame 30 takes place with the aid of the locking
means 20 by the means that the detent projection 26 engages below
an inward-projecting web 34 located on the inner side of the frame
30, in that an angled surface 28 on the outer side of the detent
projection 26 comes into contact with a correspondingly inclined
mating surface on the bottom of the web 34. In this regard, when
the cover 10 is placed in the frame 30, the detent projection 26
undergoes a forced motion in the direction toward the center of the
cover 10 against the radial preloading exerted by the oval locking
means 20. In this process, the oval locking means 20 compresses
slightly in the direction of the retaining section 25 in that the
separation between the two elongated sections 23 and 24 is
correspondingly decreased. The same temporary change in shape of
the oval locking means 20, which is enhanced by the design
described above, also occurs when the cover 10 is removed from the
frame 30, thereby bringing the detent projection 26 out of
engagement with the mating surface 36 on the frame 30.
* * * * *