Manhole cover

Abstract

Manhole cover with a frame (2) suitable for framing an opening of a manhole, with a manhole cover (1) that can be inserted into the frame (2) to close the opening of the manhole, with a latch (4) for locking the manhole cover (1) inserted into the frame (2) against opening the opening of the manhole, and with a screw (3) on which the latch (4) is arranged, wherein the latch (4) has a threaded bore (41) and a shaft (33) of the screw (3) is screwed into this threaded bore (41), wherein the latch (4) is movable between a locking position and a release position by turning the screw (3), characterized in that the screw (3) is slidably mounted in the longitudinal direction between a first end position and a second end position. - wherein an elastic element (5) is provided which holds the screw (3) in the first end position at least in the release position of the latch (4), and - wherein the screw (3) is only in the second end position when the bolt (4) is pulled against a counterpart (24a) to the bolt by means of the screw (3) in its locking position.

Description

[0001] The present invention relates to a manhole cover with a frame with which an opening of a manhole can be framed, with a manhole cover which can be inserted into the frame to close the opening of the manhole, with a bolt for locking the manhole cover inserted into the frame against opening the manhole, and with a screw on which the bolt is arranged, wherein the bolt has a threaded bore and is screwed into this threaded bore with a shank of the screw, wherein the bolt is movable, in particular pivotable, by turning the screw between a locking position and a release position.

[0002] The applicant and other companies manufacture manhole covers, which are used, for example, to cover shafts for installations, access shafts to passageways or sewers, or other openings, in order to prevent falls by people or animals, the ingress of dirt or water into the shaft, or to restrict access to the shaft. When the manhole cover is inserted into the frame, the shaft opening is closed. To prevent the manhole cover from being easily opened when closed, many manhole covers are equipped with a locking mechanism that interacts with a counterpart. In the locked position, the locking mechanism secures the manhole cover against opening, and in the unlocked position, the manhole cover can be removed from the frame to gain access to the shaft.

[0003] The locking mechanism is moved from the release position to the locking position by turning the screw in one direction and from the locking position to the release position by turning it in the opposite direction. The locking mechanism moves without relative movement to the screw. When the locking position is reached by turning the screw in the first direction, the manhole cover cannot be removed from the frame because, if an attempt is made to remove the cover, the locking mechanism strikes the counterpart and blocks its removal. When the release position is reached by turning the screw in the second direction, the locking mechanism does not strike the counterpart when the manhole cover is removed from the frame.

[0004] Further rotation of the screws in the first direction beyond the locking position of the latch, and further rotation in the second direction beyond the release position, causes the latch to move like a nut on the screw, as further rotation of the latch with the screw is prevented by a part of the manhole cover. The latch then moves along the shank of the screw towards the head of the screw or towards the end of the shank opposite the head. If the screw is turned further in the first direction after the latch has reached its locking position, the latch strikes the counterpart, causing the manhole cover to be pulled against the frame. Any previously existing gap between the latch and its counterpart is thereby reduced to zero. The cover then rests tightly against or within the frame.If the screw is turned further in the second direction while the bolt is in the release position, the bolt will strike a stop provided on the screw, which prevents the screw from being turned out of the bolt.

[0005] Due to a fault, whether a malfunction or incorrect operation, when turning the screw in the first direction to move the bolt from the release position to the locked position, the bolt may not reach the locked position. This can happen, for example, if the bolt cannot move from the release position to the locked position due to a blockage. Such a blockage can occur if, for whatever reason, the bolt is in a position relative to the longitudinal direction of the screw on the screw shaft where movement into the locked position is impossible. If the screw is then turned further in the first direction, the bolt will move further towards the head of the screw until further rotation of the screw is no longer possible. The user then has the impression that the manhole cover is locked, when in fact it is not.This can have disadvantages.

[0006] This is where the present invention comes in.

[0007] The present invention is based on the objective of proposing a manhole cover in which a user cannot get the false impression that the manhole cover is locked.

[0008] This problem is solved according to the invention by the fact that the screw is slidably mounted in the longitudinal direction between a first end position and a second end position, a. wherein an elastic element is provided which holds the screw in the first end position at least in the release position of the latch, and b. wherein the screw is only in the second end position when the bolt is pulled against the counterpart to the bolt in its locking position by means of the screw.

[0009] The elastic element can be a spring, an elastomeric part (for example, a solid cylinder made of an elastomer), or another type of elastic element. If the elastic element is a spring, it can be a coil spring.

[0010] Preferably, a manhole cover according to the invention is designed such that the latch, the screw, and the elastic element are arranged on the manhole cover, and the counterpart is arranged on the frame. To reach the second end position, if the latch is in the release position, the latch is moved into the locking position by turning the screw in the first direction. The screw remains in its first end position. If the latch is in the locking position, turning the screw in the first direction moves the latch along the screw toward the screw head until it abuts the counterpart. Rotation of the latch with the screw is then prevented by the latch abutting a part of the frame or the frame itself. The screw then remains in its first end position.After the bolt engages the counterpart, if the screw is turned further in the first direction, the bolt moves further relative to the screw. However, since it is in contact with the counterpart and its position is thus fixed, the screw moves against the force of the elastic element from its first end position to its second end position. A user can then recognize that the bolt is in the locked position by observing this second end position of the screw.

[0011] In principle, it would also be possible to position the screw, the latch, and the elastic element on the frame, and the counterpart to the latch on the manhole cover. Some of the specific features of this design variant are described below. Experts will be able to deduce the function of this design variant, as well as any features not explicitly shown, from these described features.

[0012] If the bolt, screw, and elastic element are arranged on the frame and the counterpart is on the manhole cover, then, if the bolt is in the release position, the bolt is moved into the locking position by turning the screw in the first direction. The screw remains in its first end position. If the bolt is in the locking position, turning the screw in the first direction moves the bolt along the screw towards the screw head until it abuts the counterpart. The bolt is then prevented from rotating further because it abuts a part of the manhole cover or the frame. The screw remains in its first end position. If, after the bolt has abutted the counterpart, the screw is turned further in the first direction, the bolt is moved further relative to the screw.However, since it rests against the counterpart and thus fixes the position of the bolt, the screw moves against the force of the elastic element from its first end position to its second end position. A user can then recognize that the bolt is in the locked position based on this second end position of the screw.

[0013] The elastic element can be supported at one end by the screw. If the latch, screw, and elastic element are located on the manhole cover and the counterpart is located on the frame, the elastic element can be supported at the other end by the manhole cover. Conversely, if the latch, screw, and elastic element are located on the frame and the counterpart is located on the frame, the elastic element can be supported at the other end by the manhole cover.

[0014] The screw of a manhole cover according to the invention can have a head which, if the screw is arranged on the manhole cover, can be arranged on an outside of the manhole cover or, if the screw is arranged on the frame, can be arranged on an outside of the frame, while the shaft of the screw is then arranged on an inside of the manhole cover or the frame.

[0015] The head of the screws, if provided on the manhole cover, can, in the first end position of the screw, be positioned lengthwise along the screw at a distance from the manhole cover. In this first end position, the screw head can protrude beyond the outermost surface of the manhole cover. This allows a user to recognize that the locking mechanism is not in the secured position. In the second end position of the screw, the screw head can rest against the manhole cover lengthwise. • flush with the outermost surface of the outside of the manhole cover or • Step back behind the outermost surface of the outside of the manhole cover.

[0016] If the screw is positioned on the frame, the screw head, in the first end position, may be positioned lengthwise along the screw at a distance from the frame. In this first end position, the screw head may protrude beyond the outermost surface of the frame. This allows a user to recognize that the bolt is not in the locked position. In the second end position, the screw head may also be positioned lengthwise along the frame. • flush with the outermost surface of the outside of the manhole cover or • protrude beyond the outermost surface of the manhole cover.

[0017] A first stop can be provided on the shank of the screw of a manhole cover according to the invention. If the screw is provided on the manhole cover, this first stop can, in the first end position of the screw, at least indirectly bear against the underside of the manhole cover. In the second end position of the screw, this first stop can be spaced away from the underside of the manhole cover.

[0018] If, due to an error when turning the screw in the first direction, the locking bolt does not reach its locking position, and the screw is nevertheless turned in the first direction, the locking bolt moves along the screw shaft. The screw itself does not move longitudinally and remains in its second end position. The locking bolt moves towards the head if the screw is located on the manhole cover. Turning the screw in the first direction is possible until the locking bolt reaches its first stop. Only then is further turning of the screw in the first direction no longer possible, because this would require the locking bolt and screw to rotate freely. The frame prevents this from happening if the screw is located on the manhole cover. The screw then remains in its second end position. This is how the user can recognize that the locking bolt has not reached its locking position.In a misaligned position of the bolt, the first stop of the screw can therefore at least indirectly rest against the underside of the manhole cover, and the bolt can rest against the first stop if the screw is provided on the manhole cover.

[0019] A second stop can be provided on the shaft of the screw, whereby this second stop limits the path of the locking bar on the shaft of the screw in one direction.

[0020] The first stop and / or the second stop can be formed by a pin or a screw, respectively, which are provided transversely to the longitudinal direction of the screw in the shaft of the screw.

[0021] Further features and advantages of an embodiment of the invention are described below with reference to the drawings. It shows: Fig. 1 a section of a cross-section through a manhole cover according to the invention, wherein a screw is in the first end position and a latch is in the release position, Fig. 2 the manhole cover in cross-section accordingly Fig. 1, wherein the screw is in the first end position and the bolt is in the locking position and has a distance to a counterpart, Fig. 3 the manhole cover in cross-section according to the Fig. 1 and Fig. 2, wherein the screw is in the first end position and the bolt is in the locking position and has no distance to the counterpart, Fig. 4 the manhole cover in cross-section according to the Fig. 1 to 3, wherein the screw is in the second end position and the bolt is in the locking position and has no distance to the counterpart and Fig. 4 the manhole cover in cross-section according to the Fig. 1 to 4, wherein the screw is in the first end position, the latch is in the release position and rests against a first stop on the screw which has no distance to an underside of the manhole cover.

[0022] It is not necessary for a device according to the invention to have all the features described below. It is also possible for a device according to the invention to have only individual features of the embodiment described below.

[0023] The manhole cover according to the invention comprises a manhole cover 1, a frame 2, a screw 3, a latch 4, and a spring 5. The manhole cover can be used to close the opening of a manhole. The frame 2 encloses this opening of the manhole, and the manhole cover 1 is inserted into the frame 2 to close the opening. The latch 4 prevents the manhole cover 1 from being removed from the frame 2 and thus prevents the manhole from being opened. The latch can be actuated via the screw 3.

[0024] The frame 2 is composed of several parts, including a frame part 21, a seal 22 and a latch box 23, 24, which is composed of a first side wall 23 and a part 24 forming a bottom, a cover and a second and a third side wall of the part 24.

[0025] The frame part 21 has a wall 211 that is essentially vertical in the installed position of the manhole cover and a first bearing surface 212 adjoining the lower end of the wall 211 at an essentially right angle and projecting inwards from the wall. At the end of the first bearing surface, the frame part 21 has a groove 213 in which a seal 22 of the frame 2 is inserted. At the upper end of the wall 211, a second bearing surface 212 is provided, projecting outwards perpendicularly to it, with an upwardly projecting edge at its end.

[0026] The frame part can be made from several sheet metal blanks that are bent into profiles at several points.

[0027] In one of the walls 211, namely in the section of the frame part 21 shown in the figures, a cutout is provided to which the bolt box 23, 24, open to the frame part 21, is attached.

[0028] The manhole cover 1 is also composed of several parts, including a frame part 11, a sleeve 12, a partition 13, a seal 14, a receptacle 15, 16, which is also multi-part and has a sleeve 15 and a base 16, and an edge cover 17.

[0029] The frame part 11 of the manhole cover 1 has a wall 111 and a base 112, which are set at an angle to each other that is slightly greater than a right angle. A recess is provided in the wall 111 in the immediate vicinity of the locking mechanism 23, 24. The partition 13 is arranged in the area where this recess is provided in the wall 111 and rests on the base 112 of the frame part 11 of the manhole cover 1. This partition 13 is U-shaped in plan view and has a first section 131 extending at a distance from the wall 111 with the recess, and two second sections 132 adjoining it at right angles, connecting the ends of the first section 131 to the wall 111. The partition 13 extends over the height of the wall 111 and the edge cover 17 rests on the upper end of the partition 13 as well as on the upper end of the wall 111.The wall 111, the floor 112, the partition 13, and the edge covering enclose a space. The interior of the frame section 11, with the exception of the space separated by the partition, is filled with a covering 18, for example, concrete, tar, or paving stones.

[0030] In this space, the sleeve 12 is attached to the base 112 and projects into the space. A circular recess is provided in the edge cover 17, aligned with the sleeve 12, into which the receptacle 15, 16 is inserted. This receptacle is formed by the sleeve 15, which projects into the space from the edge of the recess, and the base 16, which has a hole in its center. The screw 3 projects through this hole, its head 31 being substantially located in the receptacle 15, 16, and its shank 33 projecting into the space through the hole in the base 16 of the receptacle 15, 16. In addition to the shank 33 of the screw 3, the latch 4 and the spring 5 are located in the space.

[0031] A seal 14 is attached to the underside of the edge cover 17.

[0032] The spring 5 is a helical spring with an outer diameter equal to or slightly smaller than the inner diameter of the sleeve 12. The spring 5 is inserted into the sleeve 12. The outer diameter of the shank 33 of the screw, at its free end opposite the head 31, is also equal to or slightly smaller than the inner diameter of the sleeve 12. This end of the shank 33 of the screw 3 projects into the sleeve 12. The spring 5 is thus compressed. The spring 5 is supported by the end of the shank 33 of the screw 3 and by the base 112. It is held in place by the sleeve 12. The spring 5 pushes the screw 3 away from the base 112.

[0033] The screw 3 is also multi-part and consists of the screw head 31, a sealing ring 32 and the shaft of the screw.

[0034] The screw has two threaded holes perpendicular to its longitudinal direction, into which a screw 34, 35 is screwed, forming a first stop 34 and a second stop 35, the function of which will be explained later.

[0035] The screw 3 can assume two end positions: a first end position in which the first stop 34 rests against the underside of the base 16. The screw 3 is pressed into this position by the spring 5. In this end position, the head 31 of the screw is lifted from the base 16, and the sealing ring 32 on the projecting edge of the head 31 of the screw 3 is lifted from the outside of the edge cover 17 of the manhole cover 1. In its second end position, the sealing ring 32 on the projecting edge of the head 31 of the screw 3 rests against the outside of the edge cover 17, and at the same time, the head 31 of the screw rests against the top of the base 16. The first stop 34, however, has no contact with the base 16.

[0036] The bolt 4 is provided between the two stops 34, 35. The bolt 4 has a threaded bore 41 through which the shank of the screw is guided. The shank has an external thread in this area that is complementary to the internal thread of the threaded bore 41. Perforated washers 42 are provided above and below the bolt on the shank 33 of the screw 3. The bolt is essentially in the shape of an elongated cuboid, and the threaded bore 41 is provided near one end of the bolt 4.

[0037] The bolt 4 can assume at least two different positions, namely a locking position in which the bolt is arranged with its free end in the bolt box 23, 24, and a release position in which the free end is arranged in the space which is delimited by the wall 111, the floor 112, the partition 13 and the edge cover.

[0038] If the bolt 4 is in the locking position, the manhole cover 1 cannot be separated from the frame 2, because the bolt 4 abuts the upper wall of the bolt box 23, 24, which forms a counterpart 24a to the bolt 4. If, on the other hand, the bolt 4 is in the release position, it does not obstruct the removal of the manhole cover 2 from the frame 1.

[0039] The locking bar 4 can be removed from the release position by turning the screw 3 in a first direction (see Fig. 1) into the safety position (see Fig. 2 to 4) and by turning screw 3 in a second, opposite direction, from the locked position to the unlocked position, i.e., pivoted. A wrench flat is provided on the screw head for this purpose.

[0040] In the release position of the latch 4, the screw 3 is in its first end position, i.e., the head 31 of the screw 3 protrudes clearly beyond the outer surface of the edge cover 17. The first stop 34 rests against the underside of the base 16. The screw is pressed into this end position by the spring 5.

[0041] Is the bolt initially in the release position ( Fig. 1) and when screw 3 is then turned in the first direction, the bolt reaches the position indicated in the Fig. 2 shown locking position. The screw is also in this position. Fig. 2 shown safety position in its first end position, even if the manhole cover 1 is already locked.

[0042] If screw 3 is turned further in the first direction, synchronous rotation of the bolt 4 with the screw is limited because the bolt 4 abuts a wall of the bolt housing. The bolt 4 therefore cannot rotate with screw 3. As a result, screw 3 is screwed into the bolt, and the bolt 4 moves towards the head 31 of screw 3. The first stop 34 remains against the underside of the base 16, and the screw remains in its first end position.

[0043] When screwing screw 3 into the bolt, the bolt is also moved in the direction of the counterpart 24a and strikes the counterpart 24a ( Fig.3) The further movement of the bolt 4 relative to the counterpart 24a, and thus relative to the frame 2, is therefore blocked. Nevertheless, the screw 3 can still be turned in the first direction. During this further rotation, the screw 3 now moves longitudinally from its first end position to its second end position. This second end position is reached when further longitudinal movement of the screw 3 is blocked because the screw head 33 rests against the top of the base and simultaneously the sealing ring 32 rests against the projecting edge of the screw head on the outside of the edge cover 17. The now barely protruding screw head indicates that the manhole cover is locked and pressed against the frame.

[0044] If, due to an error, the bolt 4 cannot be pivoted into the bolt housing despite rotation in the first direction, the bolt will not reach its locking position. If the screw is then turned further in the first direction, it will also be screwed into the bolt 4. However, the bolt will then not engage the counterpart 24a, but rather the first stop 34. This does not change the longitudinal position of the screw. It remains in its second end position, even though it cannot be turned further in the first direction. The screw head 33 then protrudes clearly above the top of the edge cover 17. A user can thus recognize that the manhole cover 1 is not locked.

Claims

[1] Manhole cover with a frame (2) which is suitable for framing an opening of a manhole, with a manhole cover (1) which can be inserted into the frame (2) to close the opening of the manhole, with a latch (4) for locking the manhole cover (1) inserted into the frame (2) against opening of the opening of the manhole, and with a screw (3) on which the latch (4) is arranged, for which purpose the latch (4) has a threaded bore (41) and a shank (33) of the screw (3) is screwed into this threaded bore (41), wherein the latch (4) is movable between a securing position and a release position by turning the screw (3), characterized by that the screw (3) is mounted so as to be displaceable in the longitudinal direction between a first end position and a second end position, - wherein an elastic element (5) is provided which holds the screw (3) in the first end position at least in the release position of the bolt (4), and - wherein the screw (3) is arranged in the second end position only when the bolt (4) is pulled by means of the screw (3) in its securing position against a counterpart (24a) to the bolt. [2] Manhole cover according to claim 1, characterized by that the bolt (4), the screw (3) and the elastic element (5) are arranged on the manhole cover (1) and the counterpart (24a) on the frame (2). [3] Manhole cover according to claim 1 or 2, characterized by that the spring (5) is a helical spring. [4] Manhole cover according to claim 2 and claim 3, characterized by that the elastic element (5) is supported at one end on the screw (5) and at another end on the manhole cover (1). [5] Manhole cover according to one of claims 1 to 4, characterized by that the screw (3) has a head (33) which is arranged on an outer side of the manhole cover (1), while the shaft (33) of the screw is arranged on an inner side of the manhole cover (1). [6] Manhole cover according to claim 5, characterized by that the head (33) of the screw (3) is arranged in the first end position of the screw (3) in the longitudinal direction of the screw (3) at a distance from the manhole cover (1) [7] Manhole cover according to claim 6, characterized by that the head (33) of the screw in the first end position projects beyond an outermost surface of the outside of the manhole cover (1). [8] Manhole cover according to claim 5 or 6, characterized by that the head (33) of the screw (3) in the second end position of the screw (3) rests against the manhole cover (1) in the longitudinal direction of the screw (3). [9] Manhole cover according to claim 7, characterized bythat the head (33) of the screw (3) in the second end position of the screw (3) - is flush with the outermost surface of the outside of the manhole cover (1) or - recedes behind the outermost surface of the outside of the shaft deck (1). [10] Manhole cover according to one of claims 1 to 9, characterized by that a first stop (34) is provided on the shaft (33) of the screw (3), said first stop (34) resting at least indirectly on the underside of the shaft cover (34) in the first end position of the screw (3). [11] Manhole cover according to claim 10, characterized by that the first stop (34) in the second end position of the screw (3) has a distance to an underside in the shaft cover (1). [12] Manhole cover according to claim 10 or 11, characterized bythat the first stop (34) rests at least indirectly on the underside of the shaft cover (1) in the event of a misalignment of the screw (3) and the bolt (4) rests on the first stop (34). [13] Manhole cover according to one of claims 1 to 12, characterized by that a second stop (35) is provided on the shaft (33) of the screw (3), said second stop (35) limiting the travel of the bolt (4) on the shaft (33) of the screw (3) in one direction. [14] Manhole cover according to one of claims 10 to 13, characterized by that the first stop (34) and / or the second stop (35) are formed by pins or screws which are provided transversely to the longitudinal direction of the screw (3) in the shaft (33) of the screw (3).

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