U.S. patent application number 11/632392 was filed with the patent office on 2008-07-17 for device for locking a cover of a manhole top, and manhole top.
This patent application is currently assigned to HYDROTEC Technologies Aktiengesellschaft. Invention is credited to Wilfried Neuber.
Application Number | 20080168808 11/632392 |
Document ID | / |
Family ID | 35058334 |
Filed Date | 2008-07-17 |
United States Patent
Application |
20080168808 |
Kind Code |
A1 |
Neuber; Wilfried |
July 17, 2008 |
Device for Locking a Cover of a Manhole Top, and Manhole Top
Abstract
The invention relates to a device for locking a cover (10) of a
manhole top to the frame thereof, said device comprising at least
one locking means (16', 18') which is provided on the cover (10)
and comprises at least two interspaced, adjacent spring arms (18)
that are respectively provided with an engaging section (18a').
Said sections (18a) can be engaged with a part (6) of the frame and
held on the spring arms (18) in an elastic manner in such a way
that they can be displaced in relation to the adjacent section of
the periphery of the cover (10) at an angle smaller than a right
angle. The invention is characterised in that a blocking device
(40) is used to block the displacement of the engaging sections
(18a) as required.
Inventors: |
Neuber; Wilfried;
(Delmenhorst, DE) |
Correspondence
Address: |
TOWNSEND AND TOWNSEND AND CREW, LLP
TWO EMBARCADERO CENTER, EIGHTH FLOOR
SAN FRANCISCO
CA
94111-3834
US
|
Assignee: |
HYDROTEC Technologies
Aktiengesellschaft
Wildeshausen
DE
|
Family ID: |
35058334 |
Appl. No.: |
11/632392 |
Filed: |
July 14, 2005 |
PCT Filed: |
July 14, 2005 |
PCT NO: |
PCT/EP05/07667 |
371 Date: |
December 17, 2007 |
Current U.S.
Class: |
70/167 |
Current CPC
Class: |
Y10T 70/558 20150401;
E02D 29/1427 20130101 |
Class at
Publication: |
70/167 |
International
Class: |
B65D 55/14 20060101
B65D055/14; E02D 29/14 20060101 E02D029/14 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 14, 2004 |
DE |
20 2004 010 995.6 |
Claims
1. Device for locking a cover (10) of a manhole top to the frame
(1) thereof, comprising at least one locking means (16, 18; 16',
18') provided on the cover (10) which has at least two interspaced,
adjacent spring arms (18; 18') that are each provided with an
engaging section (18a; 18a'), whereby the engaging sections (18al;
18a') can be engaged with a portion (6) of the frame (1) and held
on the spring arms (18; 18') in an elastic manner in such a way
that the engaging sections are movable relative to the adjacent
section of the circumference (10a) of the cover (10) at an angle
that is smaller than a right angle, characterized by a blocking
device (40; 40') which blocks the movability of the engaging
sections (18a') as needed.
2. Device according to claim 1, characterized in that the blocking
device (40) is situated on the cover (10), preferably on the
underside thereof.
3. Device according to claim 1, characterized in that the blocking
device (40') is situated on the frame (1).
4. Device according to at least one of the according to claim 1,
characterized in that the blocking device (40) has a blocking
element (44, 44a) which for blocking the movability of the engaging
sections (18a') may be engaged with two adjacent spring arms (18')
and/or the engaging sections (18a') thereof.
5. Device according to claim 4, characterized in that for blocking
the movability of the engaging sections (18a') the blocking element
(44, 44a) may be inserted between two adjacent spring arms (18')
and/or the engaging sections (18a') thereof.
6. Device according to claim 4, characterized in that for blocking
the movability of the engaging sections (18a') the blocking element
(44, 44a) may be brought into contact with the spring arms (18')
and/or the engaging sections (18a') thereof.
7. Device according to claim 5, characterized in that the blocking
element (44) is wedge-shaped.
8. Device according to claim 4, characterized in that the blocking
element (44, 44a) is movably supported between a blocked position,
in which it blocks the movability of the engaging sections (18a'),
and a rest position in which it enables the movability of the
engaging sections (18a').
9. Device according to claim 8, characterized in that the blocking
element (44, 44a) is designed in such a way that in its rest
position the blocking element is located outside the spring arms
(18').
10. Device according to claim 8, characterized in that the blocking
element (44, 44a) is pivotably supported between its blocked
position and its rest position.
11. Device according to claim 10, characterized in that the
blocking element (44, 44a) is pivotably supported about its swivel
axis (46), which is essentially parallel to the cover (10).
12. Device according to claim 8, characterized by a drive device
(46') which moves the blocking element (44').
13. Device according to claim 1, characterized by a remote control
device (60), preferably coupled to the blocking device (40') via
cable or wireless link (62), for remote control of the blocking
device (40').
14. Device according to claim 12, characterized in that the remote
control device (60) for remote control of the drive device (46') is
coupled to the drive device, preferably via cable or wireless
link.
15. Device according to claim 1, characterized by a monitoring
device (64) for monitoring the operating state of the locking
means.
16. Device according to claim 15, characterized in that the
monitoring device (64) is provided for monitoring the operating
state of the blocking device (40').
17. Device according to claim 4, characterized in that the
monitoring device (64) is provided for monitoring the blocking
element (44').
18. Device according to claim 13, characterized in that the remote
control device (60) contains the monitoring device (64).
19. Device according to claim 1, characterized in that the engaging
section (18a; 18a') of the spring arms (18; 18') is movable
approximately parallel to the adjacent section of the circumference
(10a) of the cover (10).
20. Device according to claim 1, characterized in that the engaging
section (18a; 18a') of the spring arms (18; 18') extends at an
angle with respect to the adjacent section of the circumference
(10a) of the cover (10).
21. Device according to claim 19, characterized in that the
engaging section (18a; 18a') of the spring arms (18; 18') extends
approximately at a right angle with respect to the adjacent section
of the circumference (10a) of the cover (10).
22. Device according to claim 21, the cover (10) being essentially
circular, characterized in that the engaging section (18a; 18a') of
the spring arms (18; 18') extends approximately radially.
23. Device according to claim 22, characterized in that the spring
arms (18; 18') are essentially radially positioned.
24. Device according to claim 1, characterized in that the spring
arms (18') have a curved section (18d').
25. Device according to claim 24, characterized in that the curved
section (18d') is situated between the engaging section (18a') and
a further section (18e') of the spring arm (18'), with the two
sections (18a', 18e') approximately flush with one another.
26. Device according to claim 1, characterized in that the spring
arms (18; 18') extend in parallel, at least in parts.
27. Device according to claim 25, characterized in that the curved
section (18d') is outwardly curved for both spring arms (18').
28. Device according to claim 1, characterized in that the engaging
section (18a; 18a') has a wedge-shaped catch section.
29. Device according to claim 1, characterized in that the spring
arms (18; 18') are attached to the cover (10) at an end facing away
from the engaging section (18a; 18a').
30. Device according to claim 1, characterized in that the locking
means (16, 18; 16', 18') is situated on the underside of the cover
(10).
31. Device according to claim 1, the cover (10) being provided with
reinforcing ribs (14), characterized in that the locking means (16,
18; 16', 18') is situated on the cover (10) at a distance from the
reinforcing ribs (14).
32. Device according to claim 1, the cover (10) having an engaging
means (30) for a tool (32), characterized in that said engaging
means (30) is situated at a distance from the locking means (16,
18; 16', 18'), and is designed in such a way that when the tool
(32) engages with the engaging means (30) the tool may
simultaneously be engaged with a portion of the frame (1) in order
to apply leverage to the cover (10) and thus to release the cover
(10) from the frame (1), against the elastic force of the spring
arms (18; 18').
33. Device according to claim 32, characterized in that said
engaging means (30) has a recess.
34. Manhole top comprising a cover (10), a frame (1) for
accommodating the cover (10), and a device according to claim 1.
Description
BACKGROUND OF THE INVENTION
[0001] The invention relates to a device for locking a cover of a
manhole top to the frame thereof, said device comprising at least
one locking means provided on the cover which has at least two
interspaced, adjacent spring arms that are each provided with an
engaging section, whereby the engaging sections can be engaged with
a portion of a frame and held on the spring arms in an elastic
manner in such a way that the engaging sections are movable
relative to the adjacent section of the circumference of the cover
at an angle that is smaller than a right angle. The invention
further relates to a manhole top comprising a cover, a frame for
accommodating the cover, and such a device.
[0002] It is noted that in the present context the term "manhole"
is understood to mean all types of shafts, ducts, channels, and
other cavities to be covered, such as manhole shafts leading to
sewer conduits, pipeline and cable ducts, and drainage channels, so
that the term "manhole top" includes all types of tops having a
frame and a cover sealing same for all kinds of shafts, ducts,
channels, and other cavities such as manhole shafts leading to
sewer conduits, pipeline and cable ducts, and drainage
channels.
BRIEF SUMMARY OF THE INVENTION
[0003] A locking device of the aforementioned type is disclosed,
for exarnple, in DE 202 04 108.5 U1 and WO 03/076729, from which
the present invention proceeds. As described therein, the two
spring arms of each locking means lie in a plane that extends
parallel to the cover, so that the engaging sections of the spring
arms are movable in a spring-elastic manner essentially parallel to
the adjacent section of the circumference.
[0004] FR 2717840 A1 discloses a cover having locking means which
likewise comprise two parallel spring arms. However, the two spring
arms of each locking means are situated at right angles to this
known cover, and therefore also extend at right angles to the
adjacent section of the circumference of the cover, and are
designed to be movable at right angles thereto, and thus in the
radial direction, in a spring-elastic manner.
[0005] Manhole tops having a lock which typically engages in the
manner of an arresting or catching means are known and used in
various forms.
[0006] Reference is also made by way of example to WO 86/04624,
which discloses a self-locking cover for a manhole top in which,
however, each locking means comprises a single elastic arm which is
integrally molded to a reinforcing rib at the underside of the
cover and extends essentially over a portion of the circumference
of the cover and parallel thereto.
[0007] In this regard, further reference is made by way of example
to EP 0 694 654 A, which discloses a cover having two radial spring
arms which are diametrically opposed by 180.degree. and which have
at their free ends an engaging section that may be engaged with a
portion of a frame.
[0008] For a device of the aforementioned type the present
invention additionally provides a blocking device which blocks the
movability of the engaging sections as needed.
[0009] The device having a lock of the aforementioned design has
proven to be useful in practice, but since the lock is achieved by
means of a catch with the assistance of elastically flexible spring
arms, there is still the risk of unauthorized opening of the cover
by overcoming the elastic forces on the spring arms which create
the lock, in particular by use of a suitable tool by which the
cover is pried from the frame. By use of the invention this may be
prevented in a particularly effective manner by simply blocking the
movability of the engaging sections on the spring arms by means of
the blocking device provided according to the invention. Of course,
the blocking device is only able to achieve its blocking effect
when the cover is in its closed position and the engaging sections
lock the cover to the frame.
[0010] As a result of this measure according to the invention, the
cover may preferably be used without problems in security-relevant
areas. In particular, in such cases temporary welding of the cover
to the frame is unnecessary, as has often been practiced
heretofore, particularly in a makeshift manner, which, however, not
only has entailed significantly greater effort, but has also
resulted in damage to the cover and frame during subsequent
separation of the weld seam.
[0011] Alternatively, the blocking device may be situated on the
cover, preferably on the underside thereof, or on the frame of the
manhole top.
[0012] The blocking device preferably has a blocking element which
for blocking the movability of the engaging sections may be engaged
with two adjacent spring arms and/or the engaging sections thereof.
It is practical to design the blocking element in such a way that
it may be easily inserted between two adjacent spring arms and/or
the engaging sections thereof, and preferably may be brought into
contact with the spring arms and/or the engaging sections thereof.
The blocking element should have a wedge-shaped design to
facilitate engagement.
[0013] One particularly preferred embodiment of the invention is
characterized in that the blocking element is movably supported
between a blocked position, in which it blocks the movability of
the engaging sections, and a rest position in which it enables the
movability of the engaging sections. It is practical for the
blocking element in its rest position to be located outside the
spring arms so as not to impede the elastic movability of the
engaging sections and the elastic effect of the spring arms during
opening and closing of the cover.
[0014] It is understood that the blocking element is not brought
into its blocked position unless the cover is closed and the
engaging sections provided on the spring arms are locked on the
associated parts of the frame, thus locking the cover to the frame.
In contrast, the blocking element must assume its rest position
during any opening and closing of the cover so that it is possible
for the spring arms to achieve their elastic effect and for the
engaging sections to be correspondingly moved.
[0015] By means of the particularly simple design for supporting
the blocking element, the blocking element may be pivotably
supported between its blocked position and its rest position. It is
practical for the blocking element to be pivotably supported about
its swivel axis, which is essentially parallel to the cover.
Alternatively, the blocking element may also be supported so as to
be linearly movable between its blocked position and its rest
position.
[0016] For automatic actuation of the blocking device a drive
device should be provided which correspondingly moves the blocking
element.
[0017] For remote control of the blocking device a remote control
device may be provided which preferably is coupled to the blocking
device via a cable or wireless connection. It is thus possible to
block the lock from a remote location such as a control room, and
in the case of a plurality of such covers the control of the
blocking devices thereof may preferably be centralized. If the
blocking device has a blocking element which is movable by a drive
device, it is practical for the drive device to be controlled by
the remote control device.
[0018] In addition, a monitoring device may be provided for
monitoring the operating state of the locking means. It is thus
possible, in particular from a central location, to advantageously
check whether the cover is locked on the frame. It is practical for
the monitoring device to monitor the operating state of the
blocking device and preferably the position of the blocking element
in order to easily determine whether the locking means in its
closed position is actually blocked from opening.
[0019] The monitoring may preferably be centrally positioned, in
particular when multiple manhole tops are to be monitored. In
particular, for this purpose the remote control device may include
or contain the monitoring device.
[0020] If the remote control device and/or the monitoring device is
connected to the blocking device via a cable, it is preferable to
select the aforementioned placement of the blocking device on the
frame which, compared to a placement on the cover, allows the
connecting cable to be installed in a stationary and therefore
uncomplicated manner.
[0021] In particular, the engaging section of the spring arm is
movable approximately parallel to the adjacent section of the
circumference of the cover.
[0022] The engaging section of the spring arm preferably extends at
an angle with respect to the adjacent section of the cover.
[0023] In a mutual refinement of the previously mentioned
embodiments, the engaging section of the spring arm extends
approximately at a right angle with respect to the adjacent section
of the cover. For a substantially circular cover, the engaging
section of the spring arm may extend radially, and in particular
the spring arm may be essentially radially positioned.
[0024] To enhance the elastic properties the spring arm may
preferably have a curved section. The curved section may be
situated between the engaging section and a further section of the
spring arm, with the two sections approximately flush with one
another.
[0025] One particularly preferred embodiment is characterized in
that the locking means has two interspaced spring arms which
preferably extend in parallel, at least in parts, thereby allowing
the locking effect of the locking means to be enhanced. When a
curved section is provided for both spring arms, said section
should be outwardly curved, thus enabling the distance between the
two spring arms, and thus the design of the locking means, to be
kept as small as possible in this embodiment.
[0026] It is practical for the engaging section to have a
wedge-shaped catch section, so that the engagement occurs as a
locking catch. The catch section is accordingly provided with at
least one surface which is inclined in the engaging direction.
However, for an easier release it is also possible to likewise
provide a surface on the catch section that is inclined in the
opposite direction. Alternatively or additionally, the
corresponding engaging surfaces on the frame part may also be
designed as wedge-shaped or sloped inclined surfaces.
[0027] The spring arm is preferably attached to the cover at its
end facing away from the engaging section.
[0028] The locking means is usually situated on the underside of
the cover.
[0029] If the cover is provided with reinforcing ribs, the locking
means should be situated on the cover at a distance from the
reinforcing ribs, resulting in a particularly compact design of the
locking means.
[0030] In a further embodiment in which the cover has an engaging
means for a tool, this engaging means is situated at a distance
from the locking means, and is designed such that when the tool
engages with this engaging means the tool may simultaneously be
engaged with a portion of the frame in order to apply leverage to
the cover and thus to release the cover from the frame, against the
elastic force of the spring arm. This design thus allows the lid to
be pried from the frame by use of the tool without the tool acting
on the locking means. The engaging means preferably has a recess
through which the tool may be inserted.
[0031] Lastly, it is noted that two locking means are usually
provided on the cover which are situated opposite from one another,
and which for a circular cover are radially opposite.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] Preferred exemplary embodiments of the invention are
explained in greater detail below with reference to the
accompanying figures, which show the following:
[0033] FIG. 1 shows a piecewise top view of a frame of a manhole
top;
[0034] FIG. 2 shows a cross section of the frame from FIG. 1, along
the dash-dotted line II-II in FIG. 1;
[0035] FIG. 3 shows an enlarged detail view of a section of the
frame from FIG. 1 having a locking recess, in the view indicated by
arrow III in FIG. 1;
[0036] FIG. 4 shows a view of the underside of a cover for the
manhole top, having a lock in a first embodiment, in this case an
additionally blocking device provided for blocking the lock being
omitted for simplicity;
[0037] FIG. 5 shows a cross section of the cover from FIG. 4, along
the dash-dotted line V-V shown in FIG. 4, here as well the blocking
device for blocking the lock being omitted for simplicity;
[0038] FIG. 6 shows a sectional partial view of the cover from FIG.
4, along the dash-dotted line VI-VI shown in FIG. 4;
[0039] FIG. 7 shows a view of the underside of a cover for the
manhole top, having a lock in a second embodiment, in this case an
additionally provided blocking device for blocking the lock being
omitted for simplicity;
[0040] FIG. 8 shows a sectional partial view of the cover from FIG.
7, along the dash-dotted line VIII-VIII shown in FIG. 7;
[0041] FIG. 9 shows a cross section of the circumferential section
of the cover and frame arrangement, together with a tool for prying
the cover from the frame;
[0042] FIG. 10 shows a perspective lower view of the cover from
FIGS. 7 and 8 together with the blocking device provided on the
underside of the cover, the blocking device being in a rest
position;
[0043] FIG. 10a shows an enlarged sectional partial view of the
section of FIG. 10 marked by a circle;
[0044] FIG. 11 shows a perspective lower view of the cover from
FIG. 7, a blocking device being provided on the underside of the
cover according to a first preferred embodiment, and the blocking
device being in a locked position;
[0045] FIG. 11a shows an enlarged sectional partial view of the
section of FIG. 11 marked by a circle;
[0046] FIG. 12 shows a lower view of the cover from FIG. 7,
together with the blocking device provided on the underside of the
cover according to the first embodiment;
[0047] FIG. 13 shows a sectional partial view of the arrangement
from FIG. 12, along line XIII-XIII shown in FIG. 12;
[0048] FIG. 14 shows a perspective view of the top side of a
manhole top having an opened cover designed according to FIGS. 7
and 8, and accordingly having a lock according to the second
embodiment and a frame on which a blocking device is provided
according to a second embodiment;
[0049] FIG. 15 shows an enlarged sectional perspective view of the
underside of the manhole top from FIG. 14 having a closed cover, a
locking bar which forms a portion of the blocking device being
illustrated in its closed position;
[0050] FIG. 16 shows a top view of the opened manhole top from FIG.
14;
[0051] FIG. 17 shows a sectional side view of the opened manhole
top according to FIGS. 14 and 16 along line XVII-XVII shown in FIG.
16, the locking bar for the blocking device being illustrated in
its retracted lower rest position; and
[0052] FIG. 18 shows the same sectional side view of the manhole
top as in FIG. 17, except with a closed cover, the locking bar for
the blocking device being illustrated in its upper blocked
position, and also showing in a block diagram the connection of a
remote control device and a monitoring device to the blocking
device.
DETAILED DESCRIPTION OF THE INVENTION
[0053] The manhole top described below comprises an annular frame 1
and a disk-shaped cover 10 which fits same. The frame 1 is
illustrated in FIGS. 1 through 3, and the cover 10 together with a
lock is illustrated in a first embodiment in FIGS. 4 through 6 and
in a second embodiment in FIGS. 7 and 8.
[0054] The frame 1 shown in FIGS. 1 and 2 has on in its inner side
an inwardly projecting circumferential ridge 2, the upper side 2a
of which forms a support surface for the cover 10 and which lies in
a plane extending essentially horizontally in the installed state
of the frame 1. An inwardly projecting circumferential, flange-like
projection 4 is mounted on the ridge 2, which in the illustrated
exemplary embodiment is interrupted by a recess 6 at two oppositely
situated locations. As shown in FIG. 3, each of these recesses 6 is
adjoined on both sides of the flange-like projection 4 by upper and
lower inclined surfaces 6a and 6b which extend outwardly toward one
another at an acute angle.
[0055] On its underside the cover 10 has a ridge 12 running along
the circumference (see in particular FIGS. 4, 5, and 7), by means
of which the cover 10 upon insertion in the frame 1 rests on the
top side 2a of the circumferential ridge 2 on the frame 1 which
serves as a support surface. The cover 10 is also provided on its
underside with radially extending reinforcing ribs 14.
[0056] At one location on the underside of the cover 10, at a
distance from the ribs 14, a block 16 is provided onto which two
spring arms 18 are integrally molded. The spring arms 18 are
positioned on the block 16 in a free-floating manner, and extend
radially outward in the direction of the circumference 10a of the
cover 10. The spring arms 18 extend approximately in parallel to
one another and to the cover 10, at a distance from the underside
of the cover. The two spring arms 18 thus form an interspace
between one another, as shown in FIG. 4, and in the installed state
of the manhole top, with the cover 10 inserted in the frame 1, the
spring arms lie approximately in a horizontal plane running in
parallel and at a distance from the plane defined by the cover
10.
[0057] The arrangement comprising the block 16 and the pair of
spring arms 18 mounted thereon forms a locking means for locking
the cover 10 to the frame 1. For this purpose the spring arms 18
can be moved toward one another at their free ends 18a, and thus in
the direction of the circumference 10a of the cover 10, against the
effect of an intrinsic elastic restoring force, and are used as
catch elements for engaging with the recess 6 in the frame 1.
[0058] In the exemplary embodiment illustrated in FIGS. 4 and 6,
the spring arms 18 have a linear design and are provided with a
wedge-shaped exterior that is formed by a sloping upper inclined
surface 18b and a sloping lower inclined surface 18c, the two
sloping inclined surfaces 18b and 18c extending outwardly toward
one another at an acute angle, as shown in FIG. 6.
[0059] The cover 10 is thus placed on the frame 1 in such a way
that the free ends 18a of the spring arms 18 are aligned with the
recesses 6. The free ends 18a of the spring arms 18 initially come
into contact at their lower inclined surfaces 18c with the upper
inclined surfaces 6a of the recess 6 in the frame 1. As the cover
10 continues to move onto the frame 1, the upper inclined surfaces
6a of the recess 6 cause the spring arms 18 to be compressed at
their free ends 18a until the free ends pass through the narrowing
in the recess 6 formed by the two inclined surfaces 6a, 6b. The
clearance of the narrowing in the recess 6 formed by the inclined
surfaces 6a, 6b is therefore slightly larger than the total width
of the free ends 18a of the spring arms 18, viewed in the direction
of the circumference 10a of the cover 10. The spring arms 18 are
thus compressed against the action of their intrinsic elastic
restoring force until they pass through the narrowing in the recess
6. After passing through the narrowing in the recess 6, upon
continued motion of the cover 10 onto the frame 1 the intrinsic
elastic force restores the spring arms to the position shown in
FIGS. 4 and 6, causing the free ends 18a of the spring arms 18 to
then come into contact at their upper inclined surfaces 18b with
the lower inclined surfaces 6b of the recess 6, causing the
sections of the flange-like projection 4 of the frame 1 adjacent to
the recess 6 to engage from below. In the locked state the free
ends 18a of the spring arms 18 are similarly separated at a
distance from one another, as shown in FIG. 4, so that an
interspace results between the free ends 18a of the spring arms 18
in the relaxed rest state as well as in the locked state.
[0060] Thus, an arresting or catching lock is formed by the spring
arms 18 at their free ends 18a at the cover 10, and by the recesses
6 at the frame 1.
[0061] FIGS. 7 and 8 illustrate a second embodiment of the lock
provided on the underside of the cover 10. Although the spring arms
18' in this second embodiment are integrally molded onto the
underside of the cover 10 via a block 16', similarly as for the
first embodiment shown in FIGS. 4 and 6, and are similarly provided
on their exterior with upper and lower inclined surfaces 18b' and
18c', the second embodiment differs from the first in that the
spring arms 18' have an outwardly curved section 18d' between the
free end 18a' and a section 18e' adjacent to the block 16', whereby
the curved sections 18d' of the two spring arms 18' in each pair of
spring arms 18' have a symmetrical design in the second exemplary
embodiment illustrated, and the sections 18a' and 18e' are in flush
alignment. The curved sections 18d' of the spring arms 18' are used
for increasing the restoring elastic force. With regard to the
remaining features and in particular the arresting or catching lock
effect, reference is made to the previous description of the first
embodiment according to FIGS. 4 and 6.
[0062] To release the cover 10 which has been placed on the frame 1
and locked, a pin-shaped tool 32 is inserted through a recess 30
provided on the circumference 10a of the cover 10, and is engaged
with the section of the frame 1 situated thereunder such that the
tool produces a lever effect which allows the cover 10 to be lifted
from the frame 1, as shown in FIG. 9. This lever effect must be of
such a magnitude that the restoring elastic force of the spring
arms 18 or 18' is overcome, and that by lifting the cover 10 from
the frame 1 the free ends 18a or 18a' of the spring arms 18 or 18'
can be moved along the lower inclined surfaces 6b of the recess 6,
in the direction of the narrowing thereof. This compresses the
spring arms 18 or 18' once again until they pass through the
narrowing in the recess 6 as the cover continues to move away from
the frame 1.
[0063] Furthermore, a blocking device is provided in order to block
the movability of the spring arms 18 or 18' in the locked state,
thereby preventing unintentional opening of the cover 10 from the
frame 1 (for example, by use of the pin-shaped tool 32 previously
described with reference to FIG. 9). In FIGS. 4, 5, and 7 the
illustration of the blocking device has been omitted for simplicity
in order to better illustrate and describe the configuration and
design of the spring arms 18 or 18'.
[0064] FIGS. 10, 10a, 11, 11a, 12, and 13 illustrate the
configuration and design of such a blocking device 40 on the
underside of the cover 10 according to a first embodiment. In this
regard it is further noted that FIGS. 10, 10a, 11, 11a, 12, and 13
show additional details in the circumferential edge section of the
cover 10 which have been omitted in FIGS. 4, 5, and 7 for
simplicity. The cover illustrated in FIGS. 10, 11a, 11, 11a, 12,
and 13 has a lock, as has been previously described as a second
embodiment with reference to FIGS. 7 and 8. However, the following
description of the structure of the blocking device 40 and its
function with regard to the lock also similarly applies to a lock
as has been previously described as a first embodiment with
reference to FIGS. 4 through 6.
[0065] As shown in particular in FIGS. 10, 11, and 12, the blocking
device 40 in the illustrated exemplary embodiment according to the
first embodiment has an approximately cuboidal housing 41 situated
vertically and with its longitudinal extension approximately in the
radial direction. The housing 41 is attached at its inner end to a
section of the ribs 14 and to an additional pedestal 42 which is
situated in the vicinity of the center of the cover 10 and which,
similarly as for the ribs 14, projects from the underside of the
cover 10. In the housing 41 a locking bar 44 is pivotably supported
about a rotational axis 46 oriented parallel to the cover 10 and
thus, in the installed position of the cover 10, approximately
horizontally, as shown in particular in FIGS. 10a and 11a.
Similarly as for the housing 41, the locking bar 44 supported in
the housing also extends radially in the direction of the
circumference 10a of the cover 10. At its free end adjacent to the
circumference 10a of the cover 10 and located at a distance from
the rotational axis 46, the locking bar 44 projects through an
opening 48 provided in the housing 41, and has a nose 44a which
points toward the cover 10, as shown in particular in FIGS. 11a and
13.
[0066] The blocking device 40 is situated adjoining the underside
of the cover 10 and at a distance from the spring arms 18' in such
a way that the housing 41 has the same orientation as the spring
arms 18', and in addition the nose 44a of the lock 40 is in flush
alignment with the interspace 49 formed between the free ends 18a'
of the spring arms 18'.
[0067] The locking bar 44 is able to swivel between a rest position
and a blocked position. In the rest position, as shown in FIGS. 10
and 10a and readily identified in particular in FIG. 10a, the nose
44a is located outside the spring arms 18', thus preventing any
contact of the locking bar 44 with the spring arms 18'. In this
rest position of the locking bar 44 the spring arms 18' are freely
movable, as the result of which the cover 10 may be easily opened
or closed in the previously described manner by disengagement or
engagement of the free ends 18a' of the spring arms 18'
respectively out of or into the recess 6 in the frame 1 (FIGS. 1
and 3).
[0068] If the cover 10 is placed on the frame 1 and locked thereto
by engaging the free ends 18a' of the spring arms 18' behind the
sections of the flange-like projection 6 of the frame 1 which
adjoin the recess 6, it is possible to block the lock by use of the
blocking device 40 to prevent unintentional opening of the cover
10. To this end, the locking bar 44 is swiveled in the direction of
the cover 10 into a blocked position, causing the projecting nose
44a of the locking bar to engage with the interspace 49 between the
free ends 18a' of the spring arms 18'. This blocked position is
shown in FIGS. 11, 11a, and 13, and is readily identified in
particular in FIG. 13. In the blocked position the nose 44a of the
locking bar 44 then extends into the interspace 49, and thus lies
between the free ends 18a' of the spring arms 18' which are
separated from one another by the interspace 49. In this manner a
motion of the free ends 18a' of the spring arms 18' toward one
another is prevented, since such a motion would result in
constriction of the interspace 49 between the free ends 18a' of the
spring arms 18', which at that time is occupied by the projecting
nose 44a of the locking bar 44. In its blocked position between the
free ends 18a' of the spring arms 18', the projecting nose 44a of
the locking bar 44 thus acts as a type of wedge which prevents
motion of the spring arms 18' toward one another. The manner in
which the nose 44a of the locking bar 44 in its blocked position
extends into the interspace 49 between the free ends 18a' is
readily seen in particular in FIG. 13, which shows a cross section
of a section of the cover 10, the nose 44a of the locking bar 44,
and the section of the frame 1 containing the recess 6. In the
illustration of FIG. 13 the cover 10 thus rests on the frame 1 and
is locked thereto by the fact that the free ends 18a' of the spring
arms 18' contact at their outer upper inclined surfaces the lower
inclined surfaces 6b of the recess 6 (also see FIG. 3 in this
regard), thereby forming a catching lock.
[0069] To facilitate insertion of the nose 44a of the locking bar
44 into the interspace 49 when the locking bar 44 is swiveled into
the blocked position, in the illustrated exemplary embodiment the
nose 44a has the shape of a wedge, as likewise shown in FIG. 13. In
addition, in the illustrated exemplary embodiment the nose 44a of
the locking bar 44 is designed so that when it contacts the
mutually facing side surfaces of the free ends 18a' of the spring
arms 18' it arrives at the blocked position, as shown in particular
in FIG. 13.
[0070] To allow the locking bar 44 to be swiveled between the rest
position and the blocked position in the manner previously
described, the opening 48 in the housing 41 must have a
corresponding opening width, as shown in particular in FIG.
11a.
[0071] The previously described swivel motion of the locking bar 44
is preferably achieved by a drive, not shown in FIGS. 10 through 13
but located in the housing 41. It is practical for such a drive to
be electrically driven, and to have a servomotor or electromagnet,
for example. To allow control of such a drive and thus of the
swivel motion of the locking bar 44 between the rest position and
blocked position thereof from a remote location, remote control
systems (likewise not illustrated in FIGS. 1 through 13) should
also be provided. To this end, the remote control device may be
connected to the blocking device 40 by means of a connecting cable
(likewise not illustrated), or alternatively, coupled to the
blocking device by wireless link, whereby in the latter case the
associated receiver may likewise be accommodated in the housing 41.
When multiple covers are involved, it is also possible to achieve
the blocking of the lock simultaneously and/or optionally from a
remote location.
[0072] Compared to FIGS. 4 and 7, FIGS. 10, 11, and 12 also show a
pair of interspaced recesses 50 provided at the circumference 10a
of the cover 10, specifically, at a location diametrically opposite
from the spring arms 18' and the blocking device 40, and in the
exemplary embodiment extending radially and at the same time at
right angles to a plane defined by the cover 10. A pin 52 likewise
projects into the two recesses 50, and together with corresponding
bearing elements (not illustrated in FIGS. 1 and 2) provided on the
frame mutually form a hinge for pivotable bearing of the cover 10
on the frame 1 in order to swing the illustrated cover 10 up and
down for opening and closing. In addition, this hinge should be
designed so that the cover 10 may optionally be removed from the
frame 1.
[0073] As an alternative to the hinge described above, other
measures may be provided for locking and supporting the cover 10 on
the frame 1.
[0074] Although the previously described cover 10 has only a single
pair of spring arms 18 or 18' for locking, as an alternative it is
also possible, of course, to provide a plurality of such spring arm
pairs, and also to provide a corresponding number of recesses on
the frame 1.
[0075] FIGS. 14 through 18 illustrate the previously described
manhole top having a frame 1 and cover 10, the cover 10 being shown
in its open position. FIGS. 14 through 18 also show the design and
configuration of a blocking device 40' on the frame 1. In this
regard, it is further noted that FIGS. 14 through 18 show
additional details of the frame 1 and cover 10 which have been
omitted in the previously described figures for simplicity. The
cover 10 illustrated in FIGS. 14 through 18 also has a lock, as has
been previously described as a second embodiment with reference to
FIGS. 7 and 8. The following description of the blocking device 40'
and its function with regard to the lock also similarly applies to
a lock as has been previously described as a first embodiment with
reference to FIGS. 4 through 6.
[0076] As shown in FIGS. 14 through 18, in a departure from the
blocking device 40 according to the first embodiment illustrated in
FIGS. 10 through 13 the blocking device 40' according to the second
embodiment has an approximately cylindrical housing which is
vertical and which in its longitudinal extension in the installed
position of the illustrated manhole top is oriented approximately
in the vertical direction. In contrast to the first embodiment
according to FIGS. 10 through 13, the blocking device 40' according
to the second embodiment is attached to the inner side 1a of the
frame 1. For this purpose, in the illustrated exemplary embodiment
a stationary retaining clip 42' is provided at the inner side 1a of
the frame 1, and in the installed position of the manhole top
projects vertically downward from the underside of the frame 1, as
shown in particular in FIGS. 17 and 18 and in conjunction with FIG.
15. In the illustrated exemplary embodiment as shown in FIG. 15,
the cylindrical housing for the blocking device 40' is attached to
this retaining clip 42' by use of a bracket 43'.
[0077] In the illustrated exemplary embodiment, the cylindrical
housing for the blocking device 40' forms the housing of an
electric motor 46', which is a linear motor. The electric motor 46'
has a rod 46a' which is extended or retracted as a function of the
energization of the electric motor 46', and which thus performs a
reciprocal linear motion in the longitudinal direction and which at
its exterior free end projects from an opening, not shown in
greater detail in FIGS. 14 through 18, provided in the cylindrical
housing. Similarly as for the first embodiment according to FIGS.
10 through 13, the blocking device 40' according to the second
embodiment likewise has a locking bar 44' which rests on the
exterior free end of the rod 46a' for the electric motor 46'. In
contrast to the first embodiment according to FIGS. 10 through 13,
the locking bar 44' is not able to swivel, but in the illustrated
second embodiment according to FIGS. 14 through 18 is instead
supported in a linearly movable manner as a result of the
previously described configuration and action of the electric motor
46' designed as a linear motor, and specifically is located between
a lower rest position, shown in FIG. 17, in which it is fully
disengaged from the free ends 18a' of the spring arms 18' and which
is the only position in which the cover 10 can be opened and
closed, and an upper blocked position, shown in FIGS. 15 and 18, in
which the locking bar engages with the interspace 49 between the
free ends 18a' of the spring arms 18' in a similar manner as
illustrated in FIG. 13.
[0078] Instead of the described electric motor 46' designed as a
linear motor, the drive provided for such a reciprocal linear
motion of the locking bar 44' may also have any other conceivable
design that allows a linear motion of the locking bar 44'. To this
end, for example, an electromagnet or a rotary motor having a
transmission which converts the rotary motion to a linear motion
could also be considered.
[0079] As an alternative, however, a pivotable bearing of the
locking bar 44', similarly as for the first embodiment according to
FIGS. 10 through 13, is also possible in principle. For this
purpose, the locking bar 44' must be swiveled far enough into a
(lower) rest position until it is fully disengaged from the spring
arms. For a lock according to the second embodiment shown in FIGS.
7 and 8 and 10 through 13, a short swivel path would be sufficient,
since the locking bar 44' is already disengaged from the free ends
18' of the springs 18' when it is located in the expanded
interspace between the outwardly curved sections 18d' (see FIG. 15
in conjunction with FIG. 7). In contrast, for a lock having linear
spring arms 18, as has previously been described as a first
embodiment with reference to FIGS. 4 through 6, the swivel path
must be considerably longer, since the locking bar 44 in the
absence of an expanded interspace between the linear spring arms 18
must be swiveled completely away from same.
[0080] For further particulars regarding the design and function of
the blocking device 40' according to the second embodiment,
reference is made to the previous description of the blocking
device 40 according to the first embodiment with reference to FIGS.
10 through 13.
[0081] FIG. 18 also shows in a block diagram illustration a remote
control system whose function has previously been described in
conjunction with the first embodiment of the blocking device 40.
The remote control system schematically illustrated in FIG. 18 has
a remote control device 60 which is coupled via a connection 62 to
the blocking device 40', whereby this connection 62 may be designed
in the form of a cable, as illustrated by way of example in FIG.
15, or also as a wireless link. For connecting the remote control
device 60 via a permanently installed connecting cable the second
embodiment of the blocking device 40' is particularly suitable,
since it is attached to the frame 1 and is thus positioned in a
stationary manner, i.e., is not movable or contains no movable
parts, thus allowing the connecting cable to be easily installed in
a stationary manner. For the case that the connection 62 is
designed as a wireless link, the receiver should preferably be
accommodated in the blocking device 40'.
[0082] It is practical for the [remote] control device 60 to
influence the electric motor 46' for the blocking device 40', and
thus to optionally control the extension of the locking bar 44'
into its blocked position, or the retraction of the locking bar 44'
into its rest position.
[0083] In addition, according to FIG. 18 a monitoring device 64 is
provided, which in the illustrated exemplary embodiment is
contained in the remote control device 60. This monitoring device
64 is used for checking the position of the locking bar 44'. It is
thus possible to determine, in particular from a remote location,
whether the locking bar 44' is in its blocked position, and thus,
whether the cover 10 in its closed position is blocked from
opening. To this end, a sensor (not illustrated in the figures) is
provided in the blocking device 40' which detects the position of
the locking bar 44'. The output signals from this sensor are then
likewise transmitted via the connection 62 to the remote control
device 60, and from there to the monitoring device 64. Furthermore,
among other possibilities the position of the cover 10 may also be
checked, in particular to obtain additional assurance of the
results of the monitoring when blocking by the locking bar 44' is
determined. For this purpose an additional sensor (likewise not
illustrated in the figures) is required, which in particular should
be provided in the region of the hinge for the cover 10. The
monitoring device 64' should preferably have a monitor or screen on
which all relevant data may be displayed in a particularly
advantageous manner.
[0084] In particular for the use of a plurality of covers, by use
of the previously described remote control device 60 and monitoring
device 64 it is possible to perform blocking of the lock and
monitoring of the locked state of all covers simultaneously and
from a remote location such as a control panel, for example.
[0085] Lastly, it is noted that the remote control device 60 and
monitoring device 64 previously described with reference to FIG. 18
may be connected similarly as for the first embodiment of the
blocking device 40 previously described with reference to FIGS. 10
through 13.
* * * * *