EP1183434B1 - Device for locking a cover element on a support frame - Google Patents

Description

The invention relates to devices for locking a covering element, for example of the buffer or grid type, on a support frame.

It applies in particular to devices for closing inspection or inspection chimneys of an underground water network, such as manholes or sidewalks, to devices for closing technical inspection chambers of a network. underground cabling, such as hatches, and to manhole crowning devices such as road grilles.

Indeed, the inspection of water networks or cable networks running through the basement is made possible by the presence of manholes or hatches comprising a frame closed by a covering element, generally made of cast iron, placed flush with the surface of the ground.

These covering elements are locked by a locking device comprising a pivot which extends along a pivot axis crossing the thickness of the covering element and which is fixed to this element so that it can pivot in that -this ; this pivot comprises under the covering element an end region where is fixed a movable locking latch with it between a locking position where it is at least partly opposite a part of the frame or d 'a chin fixed to the latter, and a release position where it is opposite a light in the frame so that the covering element can then itself be pivoted or removed from the frame in order to free the eye, the locking and latch release positions being generally defined by stops.

So that the pivot can be actuated in rotation so as to drive the latch for locking from the locking position to the release position or vice versa, it comprises on the side of its outer end facing the eye, a meshing region suitable for fitting with an engagement region provided at one end of a removable key, when the engagement regions of the pivot and the key are in a predetermined relative position; so when these regions are nested and meshed, a rotation of the key around the pivot axis of the pivot causes the pivot to rotate.

To facilitate the operation of the cover element, the locking device is generally designed such that the key has a head also serving as an operating handle on which one can exert traction to pivot or remove the cover element.

To this end, the key has in its engagement region one or more pins extending radially outward relative to the pivot axis of the pivot which is also that of the key, and the covering element has , above the pivot engagement region, a bulkhead having a lumen whose outline is similar to that of the cross section of the key when the engagement region thereof is opposite the region of engagement of the pivot in the locked position and in the relative position allowing nesting, but of slightly larger dimensions.

Thus, when the pivot is in the locking position and the engagement regions of the key and of the pivot are opposite in their relative nesting position, the key can be introduced into the lumen of the element of covering and sliding along a section of entry ramp formed by the wall of the lumen and extending approximately in the same direction as the pivot axis of the pivot then fitted with the pivot, and therefore a rotation of the key intended to rotate the pivot slides the lug of the key along a section of retaining ramp extending in a plane approximately perpendicular to the axis, formed by the underside of the lips of the partition the cover member overhanging the engagement region of the pivot; thus, when, as a result of this movement of the “bayonet mount” type, the key has been turned enough so that the pivot is in the release position, any traction exerted on the key is transmitted to the rail of the element lips cover, and it can then be lifted from the frame for example by pivoting if it is pivotally mounted on the frame.

The key can then either be removed provided that it is rotated in the opposite direction to the previous one causing the lug to slide along the retaining ramp, followed by a translation causing a slide along the entry ramp, or be left in interlocking relationship with the pivot.

By way of example, it is possible to provide embodiments in which the engagement region of the pivot is formed at one end of the latter by a pivot head extending in the longitudinal direction thereof and having a prismatic shape with a polygonal cross section, and the region of engagement of the key is a chamber of complementary shape (a simple example being a pivot having a male "square" and a key having a female "square"), and where the lug extending radially outward is carried by the lateral surface of the engagement region of the key.

In another simple embodiment, the engagement region of the pivot is formed at one end thereof by a pivot head having at the end a slot similar to a screw head slot, and the engagement region of the key is an end bar extending radially on either side of the pivot axis and adapted to fit into the slot of the screw after having passed through an oblong opening in the upper partition of the element recovery; in this case, the regions of the strip projecting on either side of the axial body of the key themselves play the role of lugs, since after rotation of the key, these two regions of the strip extend under the lips of the partition laterally bordering the oblong lumen and thus allow the lifting of the covering element.

A drawback of these locking devices, which the invention aims to remedy, resides in the fact that an involuntary rotation of the key during the traction exerted on it to lift the covering element risks bringing the lug or the pins near the entry section of the corresponding ramp, and thus the disengagement of the key and the pivot and the tilting of the covering element either towards the frame or towards the outside thereof, thereby risking injury to the operator.

Another drawback which the invention aims to remedy is that the key being held loosely, a small force exerted on it can cause, for example when the covering element is open, its rotation, its accidental fall and even its loss, unnoticed. In this case, the disengagement takes place while the pivot is in the locking position, and if it is then possible to fold the covering element against the frame, it is impossible to lock it.

Another disadvantage consists in that, in order to be able to fit the key and the pivot, it is necessary that these are in a correct relative position, obtained only when the pivot is in the fully locked position (preferably defined by a stop) , but it suffices with a slight fortuitous pivoting of the pivot to note, after introduction of the key into the light, that the position of the pivot does not correspond to the position allowing the nesting, and that the latter has become impossible.

Yet another drawback is that the existence of the partition having a light whose periphery acts as a ramp for the lug of the key makes it necessary to create a chamber in the thickness of the covering element which must be produced during molding of the covering element by coring which complicates the molding operation and increases its duration and cost.

In addition, this chamber, which constitutes a trap for gravel and other road surface materials, the presence of which makes it difficult or impossible to introduce the key, is difficult to clean.

The invention aims to remedy as much as possible these drawbacks and mainly to avoid that the key can be unintentionally disengaged from the pivot. Preferred embodiments are intended to further remedy the other drawbacks mentioned.

To this end, the invention relates to a device for locking a covering element on a support frame, comprising a pivot which extends along a pivot axis passing through the thickness of the element cover and comprises on one side of the cover element an end region where a latch is fixed and on the other a mesh end region, and a removable key comprising a mesh end region having at least one meshing pin adapted to cooperate with a respective ramp of the covering element or of the pivot comprising an inlet section extending approximately in the same direction as the pivot axis and a retaining section s 'extending in a plane approximately perpendicular to this axis, the engagement regions of the pivot and of the key being adapted to fit together when the lug is slid towards the fixing end of the latch along the inlet section and the dislocation being made impossible when then by rotation of the key around the pivot axis the lug has been slid along the retaining section unless the key is rotated beforehand ble in reverse, characterized in that the key engagement region further has at least one retractable engagement pin urged by an elastic return member towards the free end of the key engagement region for come to engage, after interlocking of the engagement regions and rotation of a predetermined angle of the key, in the entry section and thus prevent rotation of the key in said opposite direction, that is to say in the direction allowing dislocation, unless retracting the retractable lug against the force of the return member.

Thanks to the fact that the dislocation of the key requires an action which is exerted voluntarily against the force of a return member of a lug, the risks of accidental dislocation of the key are eliminated and thus the risks of injuries to manpower inspecting manholes are avoided.

• pour coopérer avec une lumière prévue dans une cloison d'un élément de recouvrement, cette lumière présentant au moins une encoche dont au moins une partie constitue un tronçon d'entrée de rampe et étant bordée par des lèvres dont au moins une région de face inférieure constitue un tronçon de retenue de rampe, la clé comprend un corps allongé s'étendant le long d'un axe de pivotement et comportant, à proximité d'une extrémité libre où est disposée la région d'engrènement, au moins un ergot fixe d'engrènement s'étendant radialement par rapport à l'axe vers l'extérieur, et au moins un ergot rétractable d'engrènement s'étendant également radialement par rapport à l'axe vers l'extérieur ;
• le tronçon de retenue de rampe appartient à une gorge creusée circonférentiellement dans l'élément de recouvrement autour de l'axe de pivotement, et limitée par une face de butée pour l'ergot fixe de la clé ;
• la région d'engrènement du pivot et la région d'engrènement de la clé présentent des sections droites polygonales de formes approximativement semblables adaptées pour être mises en relation d'emboîtement ;
• la région d'engrènement de la clé comporte une forme générale prismatique s'étendant le long de l'axe de pivotement de la clé, dont la section droite présente une forme polygonale ;
• la région d'engrènement de la clé comporte une chambre de forme générale prismatique s'étendant le long de l'axe de pivotement de la clé et présentant une section droite polygonale, adaptée pour s'emboîter autour d'une tête du pivot de forme semblable ;
• pour coopérer avec une tête du pivot présentant au moins une encoche dont au moins une paroi constitue un tronçon d'entrée de rampe, et au moins une lèvre dont au moins une région de face inférieure constitue un tronçon de retenue de rampe, la clé comprend un corps allongé s'étendant le long d'un axe de pivotement et comportant, à proximité d'une extrémité libre où est disposée la région d'engrènement, au moins un ergot fixe d'engrènement s'étendant radialement par rapport à l'axe vers l'intérieur, et au moins un ergot rétractable d'engrènement s'étendant également radialement par rapport à l'axe vers l'intérieur ;
• le pivot comporte une tête de forme générale cylindrique à section droite circulaire comportant dans sa surface latérale au moins une gorge débouchant à une extrémité libre de la tête par une encoche dont au moins une paroi constitue un tronçon de rampe de guidage d'entrée, cette gorge étant creusée sous une lèvre du pivot dont la face inférieure constitue un tronçon de rampe de guidage de retenue ;
• la tête du pivot comporte une face de butée pour l'ergot fixe de la clé ;
• la région d'engrènement de la clé comporte une chambre de forme générale cylindrique s'étendant le long de l'axe de pivotement de la clé, adaptée pour s'emboîter autour d'une tête du pivot de forme semblable, et dans laquelle s'étendent au moins un ergot fixe et au moins un ergot rétractable ;
• la clé comprend un corps comportant une région d'engrènement présentant une chambre adaptée pour s'emboîter autour d'une tête du pivot et présentant deux lumières diamétralement opposées faisant communiquer la chambre avec l'extérieur et s'étendant dans un plan diamétral longitudinal du corps, et un élément rétractable logé partiellement dans ces lumières et portant au moins un ergot ;
• l'élément rétractable est un levier pivotant ;
• le levier pivotant comporte un doigt de manoeuvre en saillie à l'extérieur du corps, et une face de ce levier est sollicitée par un ressort en appui sur elle, constituant l'organe de rappel élastique de l'ergot rétractable ;
• l'élément rétractable est un coulisseau ;
• la clé comporte un dispositif de tirage comprenant une vis dont la tête est logée dans une échancrure du coulisseau, un anneau de manoeuvre dans lequel est vissée l'extrémité libre du corps fileté de la vis, et un ressort hélicoïdal entourant une partie du corps de la vis et constituant l'organe de rappel élastique de l'ergot rétractable ;
• la clé comporte une tête constituée sous la forme d'une poignée.

The invention may also have one or more of the following characteristics:

• to cooperate with a light provided in a partition of a covering element, this light having at least one notch, at least part of which constitutes a ramp entry section and being bordered by lips of which at least one region has a lower face is a ramp retaining section, the key comprises an elongated body extending along a pivot axis and comprising, near a free end where the engagement region is arranged, at least one fixed lug of meshing extending radially with respect to the axis towards the outside, and at least one retractable pin of meshing extending also radially with respect to the axis towards the outside;
• the ramp retaining section belongs to a groove hollowed out circumferentially in the covering element around the pivot axis, and limited by an abutment face for the fixed lug of the key;
• the pivot engagement region and the key engagement region have polygonal cross-sections of approximately similar shapes adapted to be interlocked;
• the key engagement region has a generally prismatic shape extending along the pivot axis of the key, the cross section of which has a polygonal shape;
• the key engagement region has a generally prismatic shaped chamber extending along the pivot axis of the key and having a polygonal cross section, adapted to fit around a head of the shaped pivot similar;
• to cooperate with a pivot head having at least one notch, at least one wall of which constitutes a ramp entry section, and at least one lip of which at least one lower face region constitutes a ramp retaining section, the key comprises an elongated body extending along a pivot axis and comprising, near a free end where the engagement region is arranged, at least one fixed engagement lug extending radially with respect to the inward axis, and at least one retractable engaging lug also extending radially with respect to the inward axis;
• the pivot comprises a generally cylindrical head with a circular cross section having in its lateral surface at least one groove opening at a free end of the head by a notch, the at least one wall constitutes a section of entry guide ramp, this groove being hollowed out under a lip of the pivot, the lower face of which constitutes a section of retaining guide ramp;
• the pivot head has an abutment face for the fixed lug of the key;
• the key engagement region has a generally cylindrical chamber extending along the pivot axis of the key, adapted to fit around a pivot head of similar shape, and in which s 'extend at least one fixed lug and at least one retractable lug;
• the key comprises a body comprising a meshing region having a chamber adapted to fit around a head of the pivot and having two diametrically opposite openings making the chamber communicate with the outside and extending in a longitudinal diametral plane of the body, and a retractable element partially housed in these lights and carrying at least one lug;
• the retractable element is a pivoting lever;
• the pivoting lever comprises an operating finger projecting outside the body, and one face of this lever is biased by a spring resting on it, constituting the elastic return member of the retractable lug;
• the retractable element is a slide;
• the key comprises a pulling device comprising a screw the head of which is housed in a notch of the slide, an operating ring in which is screwed the free end of the threaded body of the screw, and a helical spring surrounding a part of the body of the screw and constituting the elastic return member of the retractable lug;
• the key comprises a head constituted in the form of a handle.

• la figure 1 est une vue schématique de dessus montrant une partie d'un élément de recouvrement et d'un pivot de fixation d'un loquet appartenant à un dispositif de verrouillage selon une première forme de réalisation de l'invention,
• la figure 2 est une vue schématique de face avec coupe partielle, d'une clé appartenant à un dispositif de verrouillage selon la première forme de réalisation de l'invention,
• la figure 3 est une vue schématique extérieure de profil de la base de la clé de la figure 2,
• la figure 4 est une vue schématique de face également avec coupe partielle, d'une partie d'une variante de clé appartenant à un dispositif de verrouillage selon la première forme de réalisation,
• la figure 5 est une vue schématique extérieure de profil de la partie de clé de la figure 4,
• la figure 6 est une vue schématique en perspective d'une partie d'un pivot de fixation d'un loquet appartenant à un dispositif de verrouillage selon une deuxième forme de réalisation de l'invention,
• la figure 7 est une vue schématique de face avec coupe partielle, d'une partie d'une clé appartenant à un dispositif de verrouillage selon la deuxième forme de réalisation de l'invention,
• la figure 8 est une vue schématique extérieure de profil de la base de la partie de clé de la figure 7,
• la figure 9 est une vue schématique de face également avec coupe partielle, d'une partie d'une variante de clé appartenant à un dispositif de verrouillage selon la deuxième forme de réalisation de l'invention,
• la figure 10 est une vue schématique extérieure de profil de la partie de clé de la figure 9, et
• la figure 11 est une vue schématique en coupe d'une partie d'un élément de recouvrement en position de fermeture sur un cadre et d'un dispositif de verrouillage selon la deuxième forme de réalisation de l'invention.

Other characteristics and advantages of the invention will emerge from the description which follows of embodiments of the invention given by way of nonlimiting examples, illustrated by the accompanying drawings in which:

• FIG. 1 is a schematic top view showing part of a covering element and of a pivot for fixing a latch belonging to a locking device according to a first embodiment of the invention,
• FIG. 2 is a schematic front view with partial section of a key belonging to a locking device according to the first embodiment of the invention,
• FIG. 3 is an external schematic profile view of the base of the key in FIG. 2,
• FIG. 4 is a schematic front view also with partial section, of a part of a variant key belonging to a locking device according to the first embodiment,
• FIG. 5 is a schematic external profile view of the key part of FIG. 4,
• FIG. 6 is a schematic perspective view of part of a pivot for fixing a latch belonging to a locking device according to a second embodiment of the invention,
• FIG. 7 is a schematic front view with partial section, of a part of a key belonging to a locking device according to the second embodiment of the invention,
• FIG. 8 is a schematic external profile view of the base of the key part of FIG. 7,
• FIG. 9 is a schematic front view also with partial section, of a part of a variant key belonging to a locking device according to the second embodiment of the invention,
• FIG. 10 is an external schematic profile view of the key part of FIG. 9, and
• Figure 11 is a schematic sectional view of a portion of a cover member in the closed position on a frame and a locking device according to the second embodiment of the invention.

The frame covering element 1 shown in FIG. 1 is a pad fitted with a pivot 2 belonging to a locking device according to a first embodiment of the invention. Pivot 2, which crosses part of the thickness of the pad, extends along a pivot axis perpendicular thereto (in the drawing, perpendicular to the plane of the sheet). For fixing the pivot to the buffer, the latter comprises in its lower region (when it is in the closed position of the frame) not visible in FIG. 1, a part of the partition pierced with a hole through which the pivot is pinched between two fastening or clamping elements, for example two nuts, carried by the latter; at one end of the pivot 2 which projects below the partition, a locking latch is fixed. Projecting above this partition, the pivot comprises a base 20 separated from the partition by a seal that prevents the accidental rotation of the pivot (also not visible); the pivot is extended above the base by a prismatic head 21 extending along the pivot axis, having a polygonal cross section. Also above the partition for fixing the pivot, and at a distance therefrom, the buffer 1 comprises, extending in parallel, another partition 10, the role of which will be explained below, pierced with a light 11 more larger dimensions than those of the cross section of the prismatic head, intended to allow the passage of a pivot actuation key.

The key 3 shown in Figures 2 and 3 and that of Figures 4 and 5 are intended to actuate in rotation the pivot 2 of Figure 1. To this end, they have at one end a head 30, and starting from this head 30 , an elongated body 31 extending along a pivot axis intended during the actuation of the pivot to merge with the pivot axis thereof. At the free end of the body 31, opposite the head 30, opens a chamber 32 of prismatic shape extending along the pivot axis, having a polygonal cross section having the same shape as that of the head 21 of the pivot 2 but of very slightly larger dimensions, so that the chamber 32 can come into interlocking relation with the head 21 and that thanks to their polygonal shape (here pentagonal) these two regions end respectively of the key 3 and of the pivot 2 mesh with each other so that a rotation of the key around the pivot axis causes a rotation of the pivot and thus of the latch around this axis.

However, the head 30 of the keys of FIGS. 2 to 5 being intended to be used as a handle for lifting the plug when the key and the pivot are engaged and engaged in the release or unlocking position of the latch, it is necessary that in this position the key does not have the possibility of dislodging under the action of a simple pull exerted on it.

To this end, the lateral partition of the engagement chamber of the body of the keys of FIGS. 2 to 5 comprises, in the immediate vicinity of its free end, two lugs 33 extending radially outward and diametrically opposite, and the light 11 of the upper partition 10 of the plug has a shape similar to the outer shape of the cross section of the engagement end region of the key including these two pins but of slightly larger dimensions, in the position occupied by the key when this and the pivot are fitted in the latch locking position. Thus, the wall of two notches 12 of the light intended for the passage of the lugs 33 constitutes a section of guide ramp 13 for the lugs when the latter enter. in the buffer or covering element, which inlet section 13 extends in the same direction as the pivot axis; naturally, the dimensions of the light 11 are chosen large enough so that once the lugs 33 are no longer engaged in the notches 12 following their sliding towards the latch, the key can be turned in the light 11 to bring the pivot and the latch in the release position; the underside of the lips 14 of the partition overhanging the region of engagement of the pivot and extending in a plane perpendicular to the pivot axis also constitutes a section of ramp 15, retaining the lugs and thus the key, the region of which d 'meshing is therefore kept meshed and fitted with that of the pivot, when the latter has been rotated following its sliding in the inlet section 13; it is advantageous to provide that the partition 10 has a thickness sufficient for the regions of its lower face forming ramps are set back upwards, that is to say belong to grooves hollowed circumferentially around the pivot axis in this upper partition, so that the retaining sections 15 extend over an arc of circumference limited by an end face forming a stop 16 for the corresponding lug 33 when the key is in the release position of the latch.

Furthermore, according to the invention, while the disengagement of the keys 3 of FIGS. 2 to 5 and of the pivot 2 is made impossible when the lugs 33 are meshed under the upper partition 10 of the pad after rotation of the key from its position of introduction into the lumen and thus sliding of the pins along the retaining section 15 of the ramp, unless the key is rotated in the opposite direction beforehand, the region of engagement of the key has one or more pins additional retractable meshes intended to prevent such rotation in the opposite direction.

Thus, the key illustrated in Figures 2 and 3 has a retractable lug and that illustrated in Figures 4 and 5 has two retractable lugs.

More specifically, the lateral partition of the chamber 32 for engaging the key has two diametrically opposite openings 34 communicating the chamber with the outside and extending in a longitudinal diametral plane of the body 31 of the key, the partition comprising on either side of one of the openings, respectively, two protrusions 35 protruding outwards, arranged facing each other, in which are housed the ends of a pin 40 extending orthogonally to the pivot axis of the key. Around the spindle 40, is pivotally mounted a lever 41 movable between a position (in solid lines in FIG. 2) in which it bears against the wall of the lights 34 which is closest to the free end of the body of the key and which extends in a plane perpendicular to the axis of pivoting of the key and a position (partly sketched in broken lines) in which it is raised near the opposite wall of the lights. This lever 41, which passes through the body 31, comprises, opposite the pin 40 around which it is pivotally mounted, a part protruding out of the body of the key, comprising on the one hand a lug 42, projecting downwards along the lateral partition of the body 31 and extending up to near the plane of the free end thereof when the lever is in abutment against the lower wall of the openings, and on the other hand an operating finger 43 which then projects widely outwards and slightly upwards. The lever 41 is subjected to a return force towards its position of support against the wall of the lights 34 which is closest to the free end of the body, by an elastic return member 44 such as a steel wire to spring, one end of which is wound around the pivot pin 40 for the lever, the central part is wound around another pin 45 parallel to the first and disposed in the upper part of the chamber 32, and the opposite end is in pressure against the upper face of the lever 41 (the farthest from the lower wall of the lights 34). Thus, the lug 42 is normally, under the action of the spring 44, in the immediate vicinity of the free end of the engagement region of the key, but is retractable against the force of the member return, for example by pressing upwards, or by lifting its operating finger 43, in the direction of the head 30. If the lock is a quarter-turn lock, the two planes passing through the pivot axis of the key and respectively the direction in which extend the fixed engaging lugs 33 and the direction in which the pivoting lever 41 extends, intersect at right angles; generally, the angle is equal to that between the locking direction and the release direction, the retractable lug 42 being intended to engage in a notch 12 of the lumen 11 of the upper partition 10 of the pad when the pivot 2 is in the release position of the latch.

Indeed, when the pivot 2 is in the fully locked position (in abutment), as we have seen, it is possible simultaneously to fit the key 3 around it and to slide the fixed lugs 33 thereof in the notches 12, while the retractable lug 42 rises as a result of the presence of the upper partition 10 of the pad; then, when, the fixed pins 33 being beyond the notches, the key can be turned towards the release position of the latch, the retractable lug 42 slides on the partition until the position release is reached, the key and the pivot being always fitted and engaged; then, the retractable lug 42 is in turn facing the notch 12, and under the return force of the spring 44, it is pushed along the inlet section 13 of the ramp.

It follows that in this release position, any rotation of the key and the pivot in the opposite direction is prevented, unless retracting the lug 42 by acting on the operating finger 43 against the force of the 'return member 44. Thus, it is possible to use the head 30 of the key as a handle for lifting the pad or covering element 1. To remove the key, it is first necessary to retract the lug d retractable mesh 42, then turn the key to the latch locking position by sliding the fixed lugs 33 in the retaining section 14 of the ramp, and finally pull the key to slide the fixed lugs 33 in the inlet section 13, which can hardly be done by chance, and therefore significantly limits the risk of the buffer falling.

The lateral partition of the chamber 32 for engaging the key in FIGS. 4 and 5 also has two diametrically opposite openings 34 making the chamber communicate with the outside and extending in a longitudinal diametral plane of the body 31 of the key. These two openings constitute guide rails in which are inserted lateral wings 51 of a slide 50 passing right through the body 31 of the key and of which parts of the wings 51 which are prominent outside the body of the key constitute the retractable lugs 52.

The retraction device of the slide 50 and thus of the lugs 52 is a pulling device comprising a screw 53 extending axially in the body of the key, the head of which is housed in a notch 54 of the slide opening into the side of the slide which is close to the free end of the body of the key and clearing the chamber 32 for engaging the key sufficiently so that the fitting of the key on the pivot is not hampered by the presence of the slide; the threaded body of the screw 53 opens out between the branches of the head 30 forming a handle and its free end is screwed into a tapped hole extending radially in an operating ring 55.

To allow retraction of the slide 50 to the bottom of the lights 34 or near the bottom, and the passage of the screw 53, the body 31 of the key has a bore 36 extending the engagement chamber 32 up to in the vicinity of the end of the body connected to the head 30 of the key. The diameter of this bore 36 is large enough to accommodate an elastic return member 56 such as a helical spring with non-contiguous turns wound around a part of the length of the body of the screw 53, the length of which is chosen such that so that when the free end of the slide 50 is approximately flush with that of the body of the key and when the operating ring 55 is in abutment against the opposite end of the body, it is itself in abutment without being compressed at one end against the slide and at the opposite end against the bottom of the bore 36.

As in the previous embodiment, if the lock is a quarter-turn lock, the plane in which the lights extend and here the slide, and the diametrical plane of the body in which extend the fixed lugs 33, intersect at right angles.

When the pivot 2 is in the fully locked position (in abutment), it is possible simultaneously to fit the key 3 around it and to slide its fixed lugs 33 in the notches 12, while the slide rises as a result of the presence of the upper partition 10 of the buffer; then, when the fixed lugs 33 being beyond the notches, the key can be turned towards the latch release position, the retractable lugs 52 slide on the partition until the release position is reached, the key and the pivot being always fitted and meshed; then, the retractable lugs 52 are in turn facing the notches 12, and under the return force of the spring 56, they are pushed along the inlet section 13 of the ramp.

It follows that in this release position, any rotation of the key and the pivot in the opposite direction is prevented, unless retracting the pins 52 by acting on the operating ring 55, against the force of the return member 56. Thus, it is possible to use the head 30 of the key as a handle for safely lifting the pad 1. To disengage the key, it is first necessary to retract the retractable engaging lugs 52, then turn the key to the latch locking position by sliding the fixed lugs 33 in the retaining section 14 of the ramp, and finally to pull the key to slide the fixed lugs 33 in the inlet section 13.

While the embodiments of Figures 1 to 5 require for their use that the key is in a predetermined position relative to the lumen of the pad (first "indexing") and further that it is simultaneously in a predetermined position relative to at the head of the pivot (second "indexing"), which is not achieved if the pivot has been accidentally turned, a case which requires the pivot to be returned to the correct position by makeshift means, the embodiments of the Figures 6 to 11 are single indexing devices.

In these embodiments as in the previous ones, the pivot 2, which passes through at least part of the thickness of the pad 1 (FIG. 11), extends along a pivot axis perpendicular thereto; for fixing the pivot to the buffer, the latter comprises in its lower region (when it is in the closed position of the gaze), a partition part pierced with a hole through which the pivot passes, placed between two fixing elements, here constituted above the partition by the base 20 of the pivot separated from the partition by a seal forming a brake against the accidental unlocking of the pivot and below by tabs of the pivot folded back against the latch itself adjacent to the partition; the pivot extends above the base by a head 21 extending along the pivot axis. On the other hand, unlike the previous embodiments, it is not necessary for the pad to have another partition above the fixing partition because the ramps are produced in the head 21 of the pivot (FIG. 6) in order to cooperate also with meshing lugs which the lateral partition of the meshing chamber of a key comprises, but this time extending radially towards the interior of the chamber.

More specifically, the head 21 of the pivot 2 here has a generally cylindrical shape with a circular cross section and comprises in its lateral surface at least one groove, here two diametrically opposite grooves, intended for the passage of the pins. Each groove opens at the free end of the head 21 by a notch 22 whose wall constitutes a section of inlet guide ramp 23 extending in the same direction as the pivot axis, and is hollowed out under a lip 24 of the pivot, the underside of which constitutes a section of retaining guide ramp 25 extending in a plane perpendicular to the pivot axis and circumferentially around this axis, along an arc here of a value close to 90 °, but possibly possibly higher or lower; the end of the arc of circumference on which the groove extends is materialized by a face forming a stop 26 for the lug of the key.

The key 3 illustrated in FIGS. 7 and 8 and that of FIGS. 9 and 10 are intended to actuate the pivot 2 of FIGS. 6 and 11 in rotation. To this end, they comprise at one end a head 30 and starting from this head 30 an elongate body 31 extending along a pivot axis intended during the actuation of the pivot to merge with the pivot axis thereof. At the free end of the body 31 opposite the head 30, opens a chamber 32 here of generally cylindrical shape extending along the pivot axis, of dimensions slightly greater than those of the head 21 of the pivot 2 of such so that the chamber 32 can come into interlocking relation with the head 21.

The lateral partition of the key engagement chamber of FIGS. 7 to 11 comprises, flush with its free end, two lugs 33 extending radially inside and towards the longitudinal axis of the chamber, diametrically opposite.

It follows from this structure that, unlike the embodiments of FIGS. 1 to 5, whatever the position of the pivot, from its locking position in abutment to its release position in abutment, it is possible to fit the chamber 32 for engaging the key and the head 21 for engaging the pivot, simply by sliding the pins 33 into the notches 22. In addition, this time, the rotation of the key causing the lugs 33 to slide in the groove, does not cause any rotation of the pivot until the lugs 33 have not reached the abutment face 26 as a result of the given shapes to the bedroom and to the head.

Analogously to the embodiments of FIGS. 1 to 5, according to the invention, on the one hand the disengagement of the keys 3 of FIGS. 7 to 10 and of the pivot 2 of FIG. 6 is made impossible when the lugs 33 are meshed under the upper lip this time of the pivot after rotation of the key, unless the latter is rotated beforehand in the opposite direction, and on the other hand the region of engagement of the key has one or more retractable lugs of meshing intended to prevent such rotation in the opposite direction.

Thus, the key illustrated by FIGS. 7 and 8 comprises, like that of FIGS. 2 and 3, a retractable lug, and that illustrated by FIGS. 9 and 10 comprises two retractable lugs like that of FIGS. 4 and 5.

The key of Figures 7 and 8 having very many points in common with that of Figures 2 and 3, only will be described in detail below its characteristics which differ from the corresponding characteristics of the key of Figures 2 and 3; the corresponding elements are designated in the drawings and the description by the same reference numerals. Apart from the fact which has already been mentioned, that in the embodiment of FIGS. 7 and 8, the fixed engaging lugs 33 are interior and not exterior, and that the chamber 32 is apart from that of generally cylindrical shape and not polygonal, the essential difference relates to the pivoting lever 41 and its environment. Indeed, as here the lug 42 is intended to mesh in a notch 22 of the pivot 2, this lug must also be projecting inside the chamber 32. It follows that that of the lights 34 which does not extend not between the projections 35 where the ends of the pin 40 are housed, opens at the free end of the body 31 to allow passage to the lever 41. Thus, the lever 41 is movable between a position in which it is in abutment against a wall light 34 which extends between the projections 35 and a position in which it is raised near the opposite wall of the lights 34; depending on the position of the lever 41, a more or less large part of the lug 42, which projects downwards, extends between the side walls of the lumen which opens at the free end of the body 31; when the lever is in abutment against the lower wall of the other lumen, this lug 42 is approximately as prominent in the chamber 32 as is the fixed lug 33, and it is flush with the free end of the body 31.

Thus, when the chamber 32 is opposite the head 21 of the pivot and the fixed lugs 33 opposite the notches 22, it is possible simultaneously to fit the key around the pivot and to slide its fixed lugs in the notches, while the retractable lug 42 rises; then, when the fixed lugs 33 have reached the groove of the head 21, the key can be turned, the fixed lugs sliding along the sections of the retaining ramp 25 and the retractable lug 42 sliding on the pivot, the latter remaining then motionless; when the retractable lug 42 is in turn facing a notch 22, under the return force of the spring 44, it is pushed along the inlet section 23 of the ramp.

It follows that in this position any rotation of the key independently of the pivot is prevented, unless retracting the lug 42 by acting on the operating finger 43; the continuation of the movement of the key in the same direction, as a result of the pushing of the fixed lugs 33 on the abutment face 26 causes the pivot to the release position of the latch, the key and the pivot being always fitted and engaged; then, it is possible to use the head 30 of the key as a handle for lifting the pad 1. To remove the key, it is first necessary to retract the retractable engaging pin 42, then to turn the key until the fixed lugs 33 reach the base of the notches 22, and pull the key to slide the fixed lugs 33 along the inlet section 23.

Similarly, the key of Figures 9 and 10 having many points in common with that of Figures 4 and 5, only will be described in detail below its characteristics which differ from the corresponding characteristics of the key of Figures 4 and 5; the corresponding elements are designated in the drawings and the description by the same references digital. Apart from the fact which has already been mentioned, that in the embodiment of FIGS. 9 and 10, the fixed engaging lugs 33 are interior and not exterior, and that the chamber 32 is apart from that of generally cylindrical shape and not polygonal, the essential difference relates to the slide 50.

Here, simply, the lateral wings 51 of this slide 50 do not have protruding parts outside the body of the key, but on the other hand protruding parts in the chamber 32 which constitute the retractable lugs 52.

In this way, when the fixed lugs 33 are facing the notches 22 of the pivot, it is possible simultaneously to fit the key 3 around the pivot and to slide its fixed lugs 33 in the notches 22, while the slide goes up; then, when, the fixed pins 33 being beyond the notches, the key can be turned, the retractable pins 52 slide on the pivot until they are themselves facing the notches, and under the force return spring 56, they are pushed along the inlet section 23 of the ramp. It follows that in this position any rotation of the key relative to the pivot is prevented, unless retracting the pins 52 by acting on the operating ring 55 against the force of the return member 56 Thus, it is possible to use the head 30 of the key as a handle for safely lifting the pad 1 or more generally the covering element. To disengage the key, it is first necessary to retract the retractable engaging lugs 52, then to turn the key until the fixed lugs reach the notches 22 by sliding them in the retaining section 25, and finally to pull the key to slide the fixed pins along the inlet section 23.

It will be noted that with these embodiments, the key can be put into interlocking and meshing relation with the pivot whatever the position thereof, and also separate whatever its position thanks to the fact that there is only one indexing.

FIG. 11 illustrates a locking device comprising a pivot 2 according to FIG. 6 and a latch 6 in the locking position under a stop 70 of frame 7, as well as a removable key such as that of FIGS. 9 and 10, the pivot and the key being fitted.

Of course, the invention is not limited to the embodiments described above and shown, and we can provide others without departing from its scope, in particular embodiments in which the head of the pivot, the chamber meshing, the grooves and the lugs have particular geometric shapes so that a given covering element can be opened only by a single predetermined type of key.

Claims (16)

1. A device for locking a covering element (1) to a support frame (7), comprising a pivot pin (2) which extends along a pivot axis passing through the thickness of the covering element, and has on one side of the covering element an end region where a latch (6) is fixed and on the other an end engagement region, and a removable key (3) having an end engagement region having at least one engagement peg (33) adapted to co-operate with a respective ramp of the covering element or of the pivot pin comprising an entry section (13; 23) extending approximately in the same direction as the pivot axis and a retaining section (15; 25) extending in a plane approximately perpendicular to this axis, the engagement region of the pivot pin and that of the key being adapted to fit together when the peg (33) is slid towards the fixing end of the latch along the entry section and disengagement from fitting together being made impossible when the key is subsequently rotated about the pivot axis and the peg has then been slid along the retaining section unless the key (3) is made to perform a previous rotation in the opposite direction, characterised in that the engagement region of the key (3) moreover has at least one retractable engagement peg (42; 52) which is urged by a resilient restoring member (44; 56) towards the free end of the engagement region of the key in order, after the engagement regions have been fitted together and the key has been rotated by a predetermined angle, to engage in the entry section (13; 23) and thus to prevent the key from rotating in the said opposite direction, that is to say in the direction allowing disengagement from fitting together, unless the retractable peg is retracted in opposition to the force of the restoring member.
2. A device according to Claim 1, characterised in that in order to co-operate with a hole (11) provided in a partition (10) of a covering element (1), this hole having at least one notch (12) whereof at least a part forms an entry ramp section (13) and being bordered by lips (14) whereof at least a lower face region forms a retaining ramp section (15), the key (3) comprises an elongate body (31) extending along a pivot axis and having, close to a free end where the engagement region is disposed, at least one fixed engagement peg (33) extending radially outwards with respect to the axis and at least one retractable engagement peg (42; 52) also extending radially outwards with respect to the axis.
3. A device according to either of Claims 1 and 2, characterised in that the retaining ramp section (15) is part of a groove hollowed circumferentially out of the covering element (1) around the pivot axis and limited by a stop face (16) for the fixed peg (33) of the key.
4. A device according to any one of Claims 1 to 3, characterised in that the engagement region of the pivot pin (2) and the engagement region of the key (3) have polygonal cross-sections which are approximately similar in shape and adapted to be brought into the fitting-together condition.
5. A device according to any one of Claims 1 to 4, characterised in that the engagement region of the key (3) has a generally prismatic shape extending along the pivot axis of the key, whereof the cross-section has a polygonal shape.
6. A device according to any one of Claims 1 to 5, characterised in that the engagement region of the key (3) has a chamber (32) of generally prismatic shape which extends along the pivot axis of the key and has a polygonal cross-section, and which is adapted to be fitted around a head (21) of the pivot pin (2) of similar shape.
7. A device according to any one of Claims 1 and 4 to 6, characterised in that in order to co-operate with a head (21) of the pivot pin (2) having at least one notch (22) whereof at least one wall forms an entry ramp section (23) and at least one lip (24) whereof at least one lower face region forms a retaining ramp section (15), the key (3) comprises an elongate body (31) extending along a pivot axis and having, close to a free end where the engagement region is disposed, at least one fixed engagement peg (33) extending radially inwards with respect to the axis and at least one retractable engagement peg (42; 52) also extending radially inwards with respect to the axis.
8. A device according to any one of Claims 1 and 4 to 7, characterised in that the pivot pin (2) has a head (21) of generally cylindrical shape of circular cross-section having in its lateral surface at least one groove opening at a free end of the head in a notch (22) whereof at least one wall forms an entry guide ramp section (23), this groove being hollowed out below a lip (24) of the pivot pin whereof the lower face forms a retaining guide ramp section (25).
9. A device according to any one of Claims 6 to 8, characterised in that the head (21) of the pivot pin (2) has a stop face (26) for the fixed peg (33) of the key.
10. A device according to any one of Claims 1 and 4 to 9, characterised in that the engagement region of the key (3) has a chamber (32) of generally cylindrical shape which extends along the pivot axis of the key and is adapted to be fitted around a head (21) of the pivot pin (2) of similar shape, and in which at least one fixed peg (33) and at least one retractable peg (42; 52) extend.
11. A device according to any one of Claims 1 to 10, characterised in that the key (3) comprises a body (31) having an engagement region having a chamber (32) adapted to be fitted around a head (21) of the pivot pin (2) and having two diametrically opposed holes (34) bringing the chamber into communication with the outside and extending in a longitudinal diametric plane of the body, and a retractable element (41; 50) housed partly in these holes and bearing at least one peg (42; 52).
12. A device according to Claim 11, characterised in that the retractable element is a pivotal lever (41).
13. A device according to Claim 12, characterised in that the pivotal lever (41) has a manoeuvring finger (43) projecting outside the body (31), and a face of this lever (41) is urged by a spring (44) bearing against it, forming the resilient restoring member of the retractable peg.
14. A device according to Claim 11, characterised in that the retractable element is a slide (50).
15. A device according to Claim 14, characterised in that the key (3) has a drawing device comprising a screw (53) whereof the head is housed in a hollow (54) within the slide, a manoeuvring ring (55) into which the free end of the threaded body of the screw (53) is screwed, and a helical spring (56) surrounding part of the body of the screw and forming the resilient restoring member of the retractable peg.
16. A device according to any one of Claims 1 to 15, characterised in that the key (3) has a head (30) formed in the shape of a handle.