Roadway element for road system, road system and corresponding roadway assembly

Abstract

Roadway element for roadway device, roadway device, and corresponding roadway assembly. This roadway element for roadway device comprises a base body, a locking bar (16) movable between locking and unlocking positions of the base body, and actuating means for moving the locking bar between the locking and unlocking positions. Blocking means (40) oppose movement of the locking bar towards its unlocking position. The blocking means include a friction surface of the base body (42) and a friction surface of the locking bar (44). Elastic means (62), disposed on the side of the locking bar opposite the base body, exert stress on the friction surface of the base body and the friction surface of the locking bar against each other.The locking means define a release torque from which the locking bar moves to its release position. See Figure 5 for the abbreviation.

Description

Title of the invention: Road element for road system, corresponding road system and road assembly

[0001] The present invention relates to a road element of the type comprising:

[0002] - a basic body, such as a manhole cover or a frame,

[0003] - a movable locking bar between a locking position of the body of base and a base body unlocking position,

[0004] - suitable actuation means for moving the locking bar between its locking position and its unlocking position, and

[0005] - means for locking the locking bar to prevent movement of the locking bar from its locked position to or into its unlocked position.

[0006] A roadway device, such as a manhole cover, comprising a cover and a frame, is known from document FR2997973A1. On the inside of the cover is a movable locking bar that rotates between a locked and an unlocked position. In the locked position, the locking bar extends below an edge of the frame, thus preventing the cover from being lifted. The locking bar is connected to the cover by means of a screw whose head is located on the outside of the cover. The screw head actuates the locking bar and moves it between the locked and unlocked positions.

[0007] Other road devices are for example known from documents EP1215342A1 FR2872182A1 and FR2794789A1.

[0008] EP1215342A1 discloses a locking assembly for a road device comprising a lock and a locking / unlocking key. The lock is suitable for locking the buffer against the access opening.

[0009] FR2872182A1 discloses a road maintenance device, in particular an inspection chamber, comprising a frame and a stamp. The stamp is fitted with a lock.

[0010] FR2794789A1 describes a locking device comprising a pivot which extended by a prismatic head extending along the pivot axis and presenting a straight, notably polygonal, section.

[0011] The invention aims to provide a road element for a road device which has significant security against opening by an unauthorized person and this with economical means.

[0012] To this end, the invention relates to a road element for a road device as indicated above, characterized in that the blocking means include

[0013] - a base body friction surface and a barrette friction surface of locking, the friction surface of the base body and the friction surface of the locking bar applying to each other, and

[0014] - elastic means stressing the friction surface of the base body and the friction surface of the locking bar against each other, in that

[0015] the elastic means are arranged on the side of the locking bar opposite the base body, and in that

[0016] the locking means define a unlocking torque, which is the torque from which the locking bar moves from its locking position to or into its unlocking position.

[0017] According to particular embodiments of the road element, it may include one or more of the following characteristics:

[0018] - the actuation means comprise an actuation head and a rod actuation, in which the actuation head is adapted to cooperate with a coupling nut intended to be mounted on an actuation key, and in which the actuation rod extends along an axis of rotation;

[0019] - the base body friction surface comprises at least one partial surface of base body friction and the locking bar friction surface includes at least one associated locking bar partial friction surface, and wherein the or each base body partial friction surface applies to the associated locking bar partial friction surface, and wherein each time a base body partial friction surface and the associated locking bar partial friction surface constitute a pair of partial friction surfaces;

[0020] - the base body friction surface and the barrette friction surface locking points are located radially relative to the axis of rotation outside the actuating head;

[0021] - at least one partial base body friction surface and the one or more the partial friction surface(s) of the associated locking bar(s) are located radially with respect to the axis of rotation entirely outside the actuating head;

[0022] - the base body friction surface comprises at least one partial surface of additional base body friction and the locking bar friction surface includes at least one associated additional locking bar partial friction surface, wherein the additional base body partial friction surface and the associated additional locking bar partial friction surface constitute a pair of additional partial friction surfaces and wherein at least the pair of partial surfaces friction and the pair of additional partial friction surfaces are arranged radially opposite each other with respect to the axis of rotation;

[0023] - the road element includes a safety ring that surrounds the head actuation and which is disposed between the actuation head and the base body, and in which the safety ring is free to rotate relative to the actuation head;

[0024] - the safety ring includes a safety collar which surrounds the head actuation and which includes an annular edge projecting from the actuation head;

[0025] - the actuating head comprises two actuating ports which are separated from one another on the other hand with respect to the axis of rotation at an angle which is less than 180°, in particular less than 90° and preferably less than 60°, and in which the angle is greater than 5° and in particular greater than 10°;

[0026] - the actuating head includes a central lug; and

[0027] - the elastic means include a spring, in particular the spring comprising one or more Belleville washers.

[0028] The invention also relates to a road device comprising a road element as defined above and a complementary base body, in particular wherein the base body is a buffer and the complementary base body is a frame adapted to receive the buffer.

[0029] According to particular embodiments of the road system, it may include one or more of the following characteristics:

[0030] - in the case where the base body is a buffer and the complementary base body is a frame adapted to receive the cover; the road element includes an auxiliary locking bar, the auxiliary locking bar having a free end adapted to extend on the side of the frame opposite the cover when the cover is disposed in the frame, and the auxiliary locking bar being adapted to oppose rectilinear translational lifting of the cover out of the frame when the cover is disposed in the frame; and

[0031] - the road device includes a hinge connecting the cover to the frame.

[0032] The invention also relates to a road assembly comprising:

[0033] - a road element for a road device as defined above,

[0034] - a coupling nut, the coupling nut being adapted to cooperate with the actuating head, and

[0035] - the coupling nut being adapted to be mounted on an actuating key and to transmit the unlocking torque to the actuating head.

[0036] The invention will be better understood upon reading the following description, given solely by way of example and made with reference to the accompanying drawings, in which:

[0037] [Fig.1] Fig.1 shows in perspective a road device according to the invention, in this case a roadway manhole, in the open state, the auxiliary blocking bar being omitted;

[0038] [Fig.2] Fig.2 shows in perspective, viewed from below, the road system of the [Fig.1], the road device being in the closed and locked state;

[0039] [Fig.3] Fig.3 shows a plan view from below of a part of the road device according to the invention, the road device being in the closed and locked state;

[0040] [Fig.4] [Fig.4] is a view corresponding to that of [Fig.3], the device of road being in the closed and unlocked state;

[0041] [Fig.5] The [Fig.5] is a partial cross-sectional view of part of the road system according to the VV plan of the [Fig.3];

[0042] [Fig.6] The [Fig.6] is a view corresponding to that of the [Fig.5], with the Belleville washers, the clamping ring and the nut omitted;

[0043] [Fig.7] Fig.7 is a perspective view from above of part of the device roadworks according to the invention showing the safety ring and the actuation head;

[0044] [Fig.8] The [Fig.8] shows in perspective a coupling nut to be mounted on an actuation key for a road assembly according to the invention;

[0045] [Fig.9] Fig.9 is a top perspective view of part of an assembly of roadworks according to the invention; and

[0046] [Fig. 10] The [Fig. 10] shows a perspective view of a road assembly according to the invention, comprising the road device according to the invention.

[0047] Figure 1 shows in perspective a roadway device according to the invention, designated by the general reference numeral 2. In this case, the roadway device is a roadway manhole. The roadway device 2 defines an outer side E and an inner side I.

[0048] The road device 2 generally extends around a central axis XX. In what follows, unless otherwise indicated, the terms "radially", "axially" and "circumferentially" will be used with respect to the central axis XX.

[0049] The road device comprises a basic body, in this case a cover 4, and a complementary basic body which is complementary to the basic body, in this case a frame 6. The frame 6 delimits an access opening 8, for example to an underground installation, and the frame 6 is adapted to receive the cover 4 in order to close the access opening 8. The frame 6 extends along a central frame axis coinciding with the central axis XX.

[0050] The road device 2 includes a hinge 10 which connects the cover 4 to the frame 6 between an open position ([Fig. 1]) and a closed position (Figures 2 and 10) about a pivot axis AA. The hinge 10 is designed such that at less when the buffer 4 is in its closed position, the hinge 10 attaches the buffer 4 to the frame 6.

[0051] The road device 2 includes a road element 12 comprising the basic body, in this case the cover 4. The road element 12 is provided with a lock 14 adapted to lock the cover 4 relative to the frame 6 in the closed position.

[0052] The lock 14 is equipped with a locking bar 16 which is movable between a locking position of the base body (see Figures 2 and 3) relative to the complementary base body and an unlocking position of the base body (see [Fig. 4]) relative to the complementary base body. In its locked position, the locking bar 16 prevents the opening of the road device 2. In the unlocked position, the locking bar 16 allows the opening of the road device 2. In this case, between its locked and unlocked positions, the locking bar 16 is rotatable about an axis of rotation YY.

[0053] The pad 4 includes a pad skirt 20. This pad skirt 20 has a substantially cylindrical shape. The frame 6 includes a frame skirt 22 (or frame rebate) and a frame flange 24 extending radially inward from the frame skirt 22. In its locked position, the locking bar 16 extends radially outward from the pad skirt 20 and is adapted to engage or engage below the frame flange 24.

[0054] In its unlocked position, the locking bar 16 is entirely located radially inside the buffer skirt 20 and outside the frame rim profile 24.

[0055] The road element 12 further comprises actuating means 30 adapted to move the locking bar 16 between its locked position and its unlocked position. In this case, the actuating means 30 comprise an actuating head 32 and an actuating rod 34 integral with each other, in this case as a single unit or piece.

[0056] The actuating rod 34 extends along an axis of rotation, which is identical to the axis of rotation YY.

[0057] The actuation means 30 further comprise an actuation opening 36 formed in the locking bar 16. The actuation opening 36 is traversed by the actuating rod 34. The actuating rod 34 and the actuation opening 36 have complementary non-circular cross-sections, such that the actuating rod 34 and the locking bar 16 are rotationally fixed about the axis of rotation YY. However, the locking bar 16 is axially movable in this case by relation to the actuating rod 34 along the axis of rotation YY. In this case, the actuating rod 34 and the actuating opening 36 have a circular cross-section with flats.

[0058] More generally, a rotation of the actuating head 32 therefore causes a rotation of the locking bar 16 around the axis of rotation YY.

[0059] The actuating head 32 is adapted to cooperate with a coupling nut 100 intended to be mounted on an actuating key (see below), in order to drive the locking bar 16 in rotation.

[0060] The road element 12 also includes locking means 40 for the locking bar 16, which prevent the locking bar from moving from its locked position to or into its unlocked position ([Fig. 5]). More generally, the locking means 40 prevent the locking bar 16 from moving between its locked and unlocked positions. The locking means define a release torque, which is the torque at which the locking bar 16 moves from its locked position to or into its unlocked position. The release torque is, for example, greater than 50 Nm and advantageously greater than 75 Nm.

[0061] The locking means 40 comprise a base body friction surface 42, carried by the base body, and a locking bar friction surface 44, carried by the locking bar 16. The base body friction surface 42 and the locking bar friction surface 44 apply to each other.

[0062] In the present case, the base body friction surface 42 comprises a first partial base body friction surface 46 and the locking bar friction surface 44 comprises a first partial locking bar friction surface 47. The first partial base body friction surface 46 applies to the first partial locking bar friction surface 47.

[0063] In the present case, the base body friction surface 42 comprises a second partial base body friction surface 48 and the locking bar friction surface 44 comprises a second partial locking bar friction surface 49. The second partial base body friction surface 48 applies to the second partial locking bar friction surface 49.

[0064] Furthermore, the base body friction surface 42 comprises a third partial base body friction surface 50, and the locking bar friction surface 44 comprises a third partial locking bar friction surface 51. The third partial base body friction surface 50 applies to the third partial friction surface of locking bar 51.

[0065] Furthermore, the base body friction surface 42 comprises a fourth partial base body friction surface 52 and the locking bar friction surface 44 comprises a fourth partial locking bar friction surface 53. The fourth partial base body friction surface 52 applies to the fourth partial locking bar friction surface 53.

[0066] In each case, one of the aforementioned partial friction surfaces of the base body and the partial friction surface of the locking bar associated with the partial friction surface of the base body form a pair of partial friction surfaces. For example, the first partial friction surface of the base body 46 and the first partial friction surface of the locking bar 47 form such a pair of partial friction surfaces.

[0067] Preferably, at least two of the pairs of partial friction surfaces are arranged radially opposite each other with respect to the axis of rotation YY. In order to distinguish these two pairs of partial friction surfaces, one of these surface pairs may be designated as the "additional pair of partial friction surfaces".

[0068] In the present case, the first partial friction surface of the base body 46 and the first partial friction surface of the locking bar 47 are arranged radially opposite the second partial friction surface of the base body 48 and the second partial friction surface of the locking bar 49 with respect to the axis of rotation YY. Also, for example, the first partial friction surface of the base body 46 and the first partial friction surface of the locking bar 47 are arranged radially opposite the fourth partial friction surface of the base body 52 and the fourth partial friction surface of the locking bar 53 with respect to the axis of rotation YY.

[0069] Similarly, the third partial friction surface of the base body 50 and the third partial friction surface of the locking bar 51 are arranged radially opposite the second partial friction surface of the base body 48 and the second partial friction surface of the locking bar 49 with respect to the axis of rotation YY. Also, for example, the third partial friction surface of the base body 50 and the third partial friction surface of the locking bar 51 are arranged radially opposite the fourth partial friction surface of the base body 52 and the fourth partial friction surface of the locking bar 53 with respect to the axis of rotation YY.

[0070] In the present case, also, the third partial friction surface of the base body 50 and the third partial friction surface of the locking bar 51 are arranged radially with respect to the axis of rotation YY between, on the one hand, the first partial friction surface of the base body 46 and the first partial friction surface of the locking bar 47 and, on the other hand, the axis of rotation YY.

[0071] In the present case, similarly, the second partial friction surface of the base body 48 and the second partial friction surface of the locking bar 49 are arranged radially with respect to the axis of rotation YY between, on the one hand, the fourth partial friction surface of the base body 52 and the fourth partial friction surface of the locking bar 53 and, on the other hand, the axis of rotation YY.

[0072] In this case, the locking bar 16 comprises a locking arm 56, a central core 58 and a support arm 60. In the locking position of the locking bar 16, the locking arm 56 is engaged below the rim 24 of the frame 6.

[0073] In this case, the first partial friction surface of the locking bar 47 is carried by the support arm 60. Advantageously, the first partial friction surface of the locking bar 47 is formed by a free end of this support arm 60. This support arm 60 extends, for example, substantially parallel to the axis of rotation YY.

[0074] In this case, the second partial friction surface of the locking bar 49 is disposed on the central web 58. For example, the second partial friction surface of the locking bar 49 is formed by a projection of the central web 58.

[0075] In this case, the third partial friction surface of the locking bar 51 is disposed on the central web 58. For example, the third partial friction surface of the locking bar 51 is formed by a projection of the central web 58.

[0076] In this case, the fourth partial friction surface of the locking bar 53 is arranged on the locking arm 56.

[0077] In this case, the fourth partial friction surface of the base body 52 is arranged on the buffer skirt 20.

[0078] In an unrepresented variant, one, two or three of the aforementioned pairs of partial friction surfaces, each pair of which consists of one of the basic body partial friction surfaces and the associated locking bar partial friction surface, is or are omitted.

[0079] The locking means 40 include elastic means 62 applying friction between the base body friction surface 42 and the locking bar friction surface 44.

[0080] The elastic means 62 are arranged on the side of the locking bar 16 opposite the base body, in this case opposite the buffer 4. Preferably, the elastic means 62 comprise a spring. In this case, the spring comprises one or more overlapping Belleville washers 64, for example, four groups of three Belleville washers, for a total of 12 Belleville washers.

[0081] The locking means 40 also include in this case a nut 66 and a clamping ring 68 forming a stop surface for the Belleville washers 64. The nut 66 is screwed onto a thread 70 of the actuating rod 34. The unlocking torque is thus adjustable via the nut 66 and the thread 70.

[0082] Advantageously, the base body friction surface 42 and the locking bar friction surface 44 are located radially with respect to the rotation axis YY outside the actuating head 32. Preferably, at least one of the aforementioned pairs of partial friction surfaces is located radially with respect to the rotation axis YY entirely outside the actuating head 32. In this case, the pair of partial friction surfaces formed by the first base body friction partial surface 46 and the first locking bar friction partial surface 47 is located radially with respect to the rotation axis YY entirely outside the actuating head 32.Similarly, in this case the pair of partial friction surfaces formed by the fourth partial friction surface of the base body 52 and the fourth partial friction surface of the locking bar 53 is located radially with respect to the axis of rotation YY entirely outside the actuating head 32.

[0083] The road element 12 includes a safety ring 72 that surrounds the actuating head 32 and is positioned between the actuating head 32 and the base body, in this case the manhole cover 4. The safety ring 72 is free to rotate relative to the actuating head 32. The safety ring 72 requires only a very low rotational torque to rotate around the actuating head 32, the torque being essentially limited to the rotational torque due to the friction force generated by gravity. This rotational torque is notably much lower than the aforementioned release torque.

[0084] The safety ring 72 comprises an inner flange 74 which engages below an outer flange 76 of the actuating head 32. These two flanges axially retain the safety ring relative to the actuating head. These two flanges define a positive clearance between the ring and safety 72 and the actuating head 32 leading to the rotational freedom of the safety ring 72.

[0085] The safety ring 72 has a frustoconical outer surface, and the base body, in this case the buffer 4, has a frustoconical inner surface that complements the frustoconical outer surface of the safety ring 72. These two surfaces also bear against each other with a positive clearance, resulting in the rotational freedom of the safety ring 72. Thus, the rotation of the safety ring 72 alone is not suitable for driving the actuating head 32 to rotate about the axis YY. These frustoconical outer and inner surfaces flare outwards from the actuating rod 34, i.e., outwards E. The opening angle of the frustoconical surfaces is chosen so that the safety ring 72 is essentially free to rotate about the actuating head 32.

[0086] Furthermore (see [Fig.7]), the safety ring 72 includes a safety collar 78 which surrounds the actuating head 32 and which includes an annular edge 80 which axially protrudes from the actuating head 32 relative to the axis of rotation YY.

[0087] The base body, therefore in this case the buffer 4, advantageously includes a base body collar 82 which surrounds the safety ring 72. Advantageously, the annular edge 80 is axially flush with the base body collar 82 relative to the axis of rotation YY.

[0088] The actuation head 32 comprises two actuation ports 84 which are separated from each other with respect to the axis of rotation YY by an angle α which is less than 180°, in particular less than 90° and preferably equal to or less than 60°. The angle α is greater than 5° and in particular greater than 10°. The actuation ports 84 are eccentric with respect to the axis of rotation YY.

[0089] Advantageously, the actuation head 32 includes a central lug 86 (see [Fig.7]). The central lug 86 extends coaxially with respect to the axis of rotation YY and preferably has a cylindrical shape with a circular cross-section.

[0090] The special shape of the actuating head 32 allows the unlocking torque to be transmitted and, combined with the safety ring 72, makes the application of this unlocking torque difficult or even impossible with common tools, such as pliers, screwdrivers, metal rods or bars, or even with a chisel and hammer.

[0091] In order to apply the release torque to the actuating head 32, the invention also includes a coupling nut 100 for mounting on an actuating key (not shown) and adapted to cooperate with the actuating head 32. The coupling nut 100 is a coupling element and is shown in perspective in [Fig. 8]. The coupling nut 100 extends along a central axis of the coupling nut ZZ. The coupling nut 100 has a shape complementary to the shape of the actuating head 32. Consequently, in the present case, the nut The coupling 100 includes two actuating lugs 102 which are adapted to engage in the actuating ports 84. The actuating lugs 102 are spaced apart from each other relative to the central axis of the coupling nut ZZ by an angle [3 which is identical to the angle a. The actuating lugs 102 are eccentric relative to the central axis of the coupling nut ZZ.

[0092] The coupling nut 100 includes a central orifice 104. This central orifice 104 extends coaxially with respect to the central axis of the coupling nut ZZ and preferably has a cylindrical shape with a circular cross-section. The central orifice 104 is complementary to the central lug 86.

[0093] The external dimensions of the coupling nut 100 are such that the coupling nut 100 can engage in the safety ring 72.

[0094] The invention defines a road assembly 200 comprising the road element 12 and the coupling nut 100 (see [Fig.9]).

[0095] The road element 12 also includes an auxiliary blocking bar 300. This auxiliary blocking bar 300 is shown in [Fig. 2], but omitted in [Fig. 1]. The auxiliary blocking bar 300 is fixed to the cover 4. The auxiliary blocking bar 300 has a free end 302 that is adapted to extend on the side of the frame 6 opposite the cover 4 when the cover is positioned within the frame, i.e., when the road device 2 is closed. More specifically, in this configuration, the free end 302 extends below the frame rim 24. The auxiliary blocking bar 300 is thus adapted to prevent, or opposes, the cover 4 from being lifted out of the frame 6 when the cover is positioned within the frame. The lifting movement which the blocking bar 300 opposes is a vertical movement in the installed state of the road device 2, namely a rectilinear translational movement along the central axis XX.

[0096] Thus, when the hinge 10 is destroyed or disabled, for example during an attempted break-in, while the locking bar 16 is in its locked position, the auxiliary locking bar 300 prevents the pad 4 from being lifted out of the frame. The free end 302 includes at least one hooking surface 304 that engages against the frame 6. Advantageously, the free end 302 is located, with respect to the central axis XX, substantially opposite the locking bar 16. Similarly, advantageously, the free end 302 is circumferentially aligned with the hinge 10 with respect to the central axis XX. The auxiliary locking bar 300, and more particularly its free end 302, allows the pad to rotate relative to the frame 6 around the pivot axis of the hinge 10.

[0097] The auxiliary locking bar 300 can be provided independently of the locking bar 16, the actuating means 30 and the locking means 40 previously described. The auxiliary locking bar 300 can, for example, be placed on a road device equipped with a known lock suitable for locking the cover relative to the frame.

[0098] In an alternative not shown, the road device is an access hatch to underground installations, in particular an access hatch to telecommunications installations.

[0099] In an unrepresented variant, the basic body and the complementary basic body are reversed, i.e. the basic body is the frame 6 and the complementary basic body is the buffer 4. As a result, according to this variant, the locking bar 16 is arranged on the frame 6, and in the locking position, the locking bar cooperates with the buffer 4.

[0100] Alternatively, the Belleville 64 washers are replaced by other springs, such as helical springs.

[0101] The arrangement of the elements described above leads to a relatively uniform distribution of locking forces and to a locking torque that is quite large for given clamping forces by elastic means.

[0102] The device according to the invention has a high level of safety and is economical to manufacture.

[0103] The preceding description contains technical features of the invention. These technical characteristics, although presented in a technical context and possibly in combination with other technical characteristics, can each time be used individually, without the other technical characteristics, insofar as this is technically possible.

Claims

Demands

1. A road element for a road device, comprising: - a basic body, such as a manhole cover (4) or a frame (6), - a locking bar (16) movable between a locking position of the basic body and an unlocking position of the basic body, - actuating means (30) adapted to move the locking bar (16) between its locking position and its unlocking position, and - blocking means (40) for the locking bar (16) opposing movement of the locking bar from its locking position to or into its unlocking position, characterized in that the blocking means (40) comprise - a friction surface of the basic body (42) and a friction surface of the locking bar (44), the friction surface of the basic body and the friction surface of the locking bar bearing against each other,and - elastic means (62) stressing the friction surface of the base body and the friction surface of the locking bar against each other, in that the elastic means (62) are disposed on the side of the locking bar opposite the base body, and in that the locking means (40) define a release torque, which is the torque from which the locking bar moves from its locked position to or into its unlocked position.

2. A street element for a street device, according to claim 1, wherein the actuation means (30) comprise an actuation head (32) and an actuation rod (34), wherein the actuation head (32) is adapted to cooperate with a coupling nut (100) intended to be mounted on an actuation key, and wherein the actuation rod (34) extends along an axis of rotation (YY).

3. A road element for a road device, according to claim 1 or 2, wherein the base body friction surface (42) comprises at least one partial base body friction surface (46, 48, 50, 52) and the locking bar friction surface (44) comprises at least one partial surface of associated locking bar friction (47, 49, 51, 53), and wherein each or every partial friction surface of base body (46, 48, 50, 52) applies to the associated partial friction surface of locking bar (47, 49, 51, 53), and wherein each time a partial friction surface of base body and the associated partial friction surface of locking bar constitute a pair of partial friction surfaces.

4. A road element for a road device, according to claim 2 or claims 2 and 3 taken together, wherein the friction surface of the base body (42) and the friction surface of the locking bar (44) are located radially with respect to the axis of rotation (YY) outside the actuating head (32).

5. A road element for a road device, according to claim 4 or claims 3 and 4 taken together, wherein at least one partial friction surface of the base body (46, 48, 50, 52) and the associated partial friction surface(s) of the locking bar (47, 49, 51, 53) are located radially with respect to the axis of rotation entirely outside the actuating head (32).

6. A road element for a road device, according to at least claim 3, wherein the base body friction surface (42) comprises at least one additional base body partial friction surface (46, 48, 50, 52) and the locking bar friction surface (44) comprises at least one associated additional locking bar partial friction surface (47, 49, 51, 53), wherein the additional base body partial friction surface (46, 48, 50, 52) and the associated additional locking bar partial friction surface (47, 49, 51, 53) constitute a pair of additional partial friction surfaces and wherein at least the pair of partial friction surfaces and the pair of additional partial friction surfaces are arranged radially opposite each other with respect to the axis of rotation (YY).

7. A road element for a road device according to claim 2 or any one of claims 3 to 6 taken in dependence on claim 2, wherein the road element comprises a safety ring (72) which surrounds the actuating head (32) and which is disposed between the actuating head and the base body, and wherein the safety ring (72) is free to rotate relative to the actuating head (32).

8. A street element for a street device according to claim 7, in which the safety ring (72) includes a safety collar (78) which surrounds the actuating head and which includes an annular edge (80) projecting from the actuating head (32).

9. A road element for a road device according to at least claim 2, wherein the actuating head comprises two actuating orifices (84) which are separated from each other with respect to the axis of rotation (YY) by an angle (a) which is less than 180°, in particular less than 90° and preferably less than 60°, and in which the angle (a) is greater than 5° and in particular greater than 10°

10. A street element for a street device according to at least claim 2, wherein the actuation head comprises a central lug (86).

11. A road element for a road device according to any one of the preceding claims, wherein the elastic means (62) comprise a spring, in particular the spring comprising one or more Belleville washers (64).

12. Road device (2) comprising a road element (12) according to any one of the preceding claims and a complementary base body, in particular wherein the base body is a manhole cover (4) and the complementary base body is a frame (6) adapted to receive the manhole cover.

13. A road maintenance device according to claim 12, wherein, where the basic body is a manhole cover (4) and the complementary basic body is a frame (6) adapted to receive the manhole cover, the road maintenance element (12) comprises an auxiliary locking bar (300), the auxiliary locking bar having a free end (302) adapted to extend from the side of the frame (6) opposite the manhole cover (4) when the manhole cover is disposed in the frame, and the locking bar auxiliary (300) being adapted to oppose a rectilinear translational lifting of the buffer out of the frame when the buffer is disposed in the frame.

14. Road device according to claim 13, wherein the road device includes a hinge (10) connecting the cover to the frame.

15. Road assembly (200) comprising: - a road element (12) for a road device according to at least claim 2, - a coupling nut (100), the coupling nut being adapted to cooperate with the actuating head (32), and - the coupling nut being adapted to be mounted on an actuating key and to transmit the release torque to the actuating head (32).

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