AU2009202849A1

AU2009202849A1 - A modular electrical appliance including a label-protecting cover and a label support pull-tab

Info

Publication number: AU2009202849A1
Application number: AU2009202849A
Authority: AU
Inventors: Eric Girauldon
Original assignee: Legrand SNC; Legrand France SA
Current assignee: Legrand SNC; Legrand France SA
Priority date: 2008-07-15
Filing date: 2009-07-14
Publication date: 2010-02-04
Anticipated expiration: 2029-07-14
Also published as: ES2458869T3; EP2146363B1; FR2934094A1; BRPI0901985B1; AU2009202849B2; CN101630599B; EP2146363B9; RU2530797C2; BRPI0901985A2; FR2934094B1; EP2146363A1; MX2009007560A; RU2009127173A; CL2009001566A1; CN101630599A; PL2146363T3

Description

Pool Secion 29 Regulation 3.2(2) AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Application Number: Lodged: Invention Title: A modular electrical appliance including a label-protecting cover and a label support pull-tab The following statement is a full description of this invention, including the best method of performing it known to us: P111ABAU/1207 1 A MODULAR ELECTRICAL APPLIANCE INCLUDING A LABEL PROTECTING COVER AND A LABEL-SUPPORT PULL-TAB TECHNICAL FIELD TO WHICH THE INVENTION RELATES 5 The present invention relates in general to modular appliances, i.e. to appliances that are designed to be placed touching one another, side-by-side on a common support. More particularly, the invention relates to a 10 modular electrical appliance comprising a casing having a front face provided with an identifying portion, a label protecting cover that co-operates with said identifying portion to define a reception housing that is open to the outside via a slot, and a pull-tab that is mounted to 15 move in translation in said reception housing through the slot, said pull-tab including a rim along one side, said rim being adapted to close said slot at least in part when the pull-tab is fully engaged in said reception housing. 20 TECHNOLOGICAL BACKGROUND Document ITMI970366U discloses a modular appliance of the above-specified type in which the pull-tab, which is adapted to support a label for identifying the modular 25 appliance, slides freely in a reception housing defined on the casing. The main drawback of that modular appliance lies in the fact that it is difficult to put a label into place on the pull-tab. 30 In order to put the label into place on the pull tab, the panel builder or installer needs to hold the pull-tab in one hand on the casing outside its reception housing, while using the other hand to place the label properly on the corresponding face of the pull-tab. 35 OBJECT OF THE INVENTION To remedy the above-mentioned drawbacks of the state 2 of the art, the present invention proposes a novel modular electrical appliance in which putting the identifying label into place on the identifying portion of the casing, and removing it therefrom, are made 5 easier. More particularly, according to the invention, there is provided a modular electrical appliance of the type defined in the introduction, which appliance includes blocking means for preventing the pull-tab from moving 10 relative to the casing when the pull-tab is in a projecting position outside said reception housing. Thus, by means of the invention, the installer can advantageously prevent the pull-tab from moving relative to the casing when it is outside its reception housing, 15 thereby having easy access to the front face of said pull-tab for putting the identifying label of the modular appliance into place or for removing it. In addition, said blocking means make it possible, while the modular appliance is being manipulated, to 20 avoid the pull-tab coming out of its reception housing and losing the label it supports. Other characteristics of the modular electrical appliance of the invention that are non-limiting and advantageous are as follows: 25 the appliance includes blocking means for preventing the pull-tab from moving when the pull-tab is in a retracted position in which it is fully engaged inside said reception housing; - said blocking means act between the pull-tab and 30 the casing; - said blocking means act between the pull-tab and the label-protecting cover; - said blocking means are reversible snap-fastener means; 35 said blocking means are friction means; - said blocking means are jamming means; said blocking means are releasable catch means; 3 - the blocking means comprise at least one tooth projecting from the rear face of the pull-tab and at least one housing for the tooth, this housing being defined between a ramp and a stop placed facing the ramp 5 on the identifying portion of the casing; - each ramp presents two opposite inclined slopes united via a rounded top; - the pull-tab is in the form of a plate having a front face surrounded by a rib that defines a housing for 10 a label, the rib presenting a local reduction in its height; - said rib presents reduced height at two different locations, each occupying the same distance along two parallel sides of said plate; 15 said rib is locally interrupted; - the plate includes a notch where said rib is interrupted, the notch opening out into the edge of said plate; - the appliance includes guide means for guiding the 20 movement of the pull-tab in translation in its reception housing, which guide means act between the identifying portion and the pull-tab; and . said guide means include at least one groove in said identifying portion, the bottom of the groove having 25 a portion of said blocking means provided therein. DETAILED DESCRIPTION OF AN EMBODIMENT The following description with reference to the accompanying drawings, given by way of non-limiting 30 example, shows clearly what the invention consists in and how it can be reduced to practice. In the accompanying drawings: - Figure 1 is a diagrammatic perspective view of a modular electrical appliance of the invention with its 35 pull-tab in the retracted position; 4 - Figure 2 is a diagrammatic perspective view of the Figure 1 appliance with its pull-tab in its position projecting from the casing; - Figure 3 is a diagrammatic exploded perspective 5 view showing a detail of rhe identifying portion provided with a label-protecting cover and with the pull-tab of the Figure 1 appliance; - Figure 4 is a front view of the Figure 1 appliance without its label-protecting cover and without its pull 10 tab; - Figure 5 is a rear view of the label-protecting cover and of the associated pull-tab of the Figure 1 appliance; - Figure 6 is a diagrammatic perspective view of 15 another modular electrical appliance of the invention with its pull-tab in the retracted position; - Figure 7 is a diagrammatic perspective view of the Figure 6 appliance with its pull-tab in its position projecting from the casing; 20 Figure 8 is a close-up diagrammatic exploded perspective view showing the identifying portion provided with the label-protecting cover and the pull-tab of the Figure 6 appliance; and - Figure 9 is a rear view of the label-protecting 25 cover and of the associated pull-tab of the Figure 6 appliance. Figures 1, 2, 6, and 7 show two different modular electrical appliances. In this example they are trip switches. 30 Each modular electrical appliance includes an insulating casing 10; 20 in the form of a generally rectangular slab. The casing 10; 20 comprises two parallel main side faces 11; 21 extending up the entire height of said 35 casing, together with a front face 12; 22, a rear face 13; 23, a top transverse face 14; 24, and a bottom 5 transverse face 15; 25, all perpendicular to said main side faces 11; 21. The casings 10; 20 are of standardized width, measured from one of its two main side faces 11; 21 to 5 the other, which width is equal to one or more times a base width, or "basic module" that is about 18 millimeters (mm). In particular, the casing 10 of the modular electrical appliance shown in Figures 1 and 2 presents a 10 width equal to the basic module, while the casing 20 of the modular electrical appliance shown in Figures 6 and 7 presents a width equal to twice the basic module. In the example shown in Figures 1 and 2, the casing 10 is constituted by a plurality of insulating partitions 15 united by a common front plate. The partitions present main side faces that touch one another, their stacked edge faces forming the rear, top transverse, and bottom transverse faces of said casing. Nevertheless, in a variant that is not shown, it is 20 possible to provide for the casing to be constituted by two shells of half-width that are assembled via their edges in a median join plane, each shell including one of the main side faces of the casing. In the example shown in Figures 6 and 7, the casing 25 20 is made up of two shells that are assembled together via their edges in the join plane J. In its rear face 13; 23, the casing 10; 20 of each modular electrical appliance includes, in conventional manner, a recess 13A; 13B for mounting the modular 30 appliance on a rail (not shown). Likewise in conventional manner, the rear face 13; 23 also includes mounting means for pressing the rail against the bottom of the recess 13A; 23A. In this example, the mounting means comprise one or 35 two latches 13B; 23B that extend along the rear face 13; 23 of the casing 10; 20. In the examples shown in the figures, two latches 13B; 23B are provided that extend on 6 either side of the recess 13A; 23A perpendicularly thereto. Each latch 13B; 23B is slidably mounted on the rear face 13; 23 of the casing 10; 20 and it includes resilient return means urging the latch 13B; 23B into its 5 locking position in which one of its free ends extends into the recess 13A; 23A. Naturally, and alternatively, it would be possible to provide any other mounting means known to the person skilled in the art. 10 Projecting from the front face 12; 22 of its casing 10; 20, in the middle zone thereof, each modular electrical appliance includes a facade portion 16; 26 whereby said casing 10; 20 is designed to project through a front panel (not shown) via a window in the panel, when 15 the casing is on position on a rail, e.g. in a cabinet. On the front face 12; 22 of the casing 10; 20, which is the front face of the face portion 16; 26; each modular electrical appliance includes an operating lever 16A; 26A enabling the modular electrical appliance to be 20 activated manually. As shown more particularly in Figures 3, 4, and 8, the front face 12; 22 of the casing 10; 20 of each modular electrical appliance shown is provided with an identifying portion 17; 27. 25 This identifying portion is associated with the front face 12; 22 of the facade portion 16; 26, and more particularly with an end portion of said front face 12; 22. In addition, as shown in Figures 1, 2, 3, 6, 7, and 30 8, each modular electrical appliance includes a label protecting cover 110; 210 that co-operates with said identifying portion 17; 27 to define a reception housing that opens to the outside via a slot, and a pull-tab 120; 220 suitable for receiving a label, which pull-tab is 35 mounted to move in translation between a projecting position and a position retracted into said reception housing through the slot.

7 The pull-tab 120; 220 includes a rim 121; 221 along one side, said rim being adapted to close at least part of said slot when the pull-tab 120; 220 is fully engaged in its reception housing defined between the label 5 protecting cover 110; 210 and the identifying portion 17; 27 of the casing 10; 20. Said rim 121; 221 remains accessible to the installer when the pull-tab 120; 220 is fully engaged in its reception housing, thereby constituting a grip rim 10 enabling the installer to take hold of the pull-tab 120; 220 so as to move it in translation towards its position projecting out from the reception housing. In accordance with the invention, each modular electrical appliance shown in the various figures 15 includes blocking means 126, 19, 18; 226, 29, 28 for preventing the pull-tab 120; 220 from moving relative to the casing 10; 20 when in its projecting position outside its reception housing (see Figures 2 and 7). Advantageously, each modular electrical appliance 20 also includes blocking means 126, 19, 16B; 226, 29, 26B for preventing the pull-tab 120; 220 from moving when in its retracted position in which the pull-tab 120; 220 is fully engaged inside its reception housing. In the examples shown, said blocking means 126, 19, 25 18, 16B; 226, 29, 28, 26B act between the pull-tab 120; 220 and the casing 10; 20, however in another variant that is not shown, provision can be made for said blocking means to act between the pull-tab and the label protecting cover. 30 Here said blocking means 126, 19, 18, 16B; 226, 29, 28, 26B are reversible snap-fastener means, however in other variants that are not shown, provision can be made for said blocking means to be friction means, jamming means, or releasable catch means. 35 In the embodiment shown, the identifying portion 17; 27 is set back a little by a distance d from the main portion of the front face 12; 22 with which it is 8 associated, and it extends parallel to said front face 12; 22 from a transverse shoulder 16B; 26B thereof. At its sides, parallel to the main side faces 11; 21 of the casing 10; 20, and set back therefrom, the 5 identifying portion 17; 27 includes two grooves of L shaped section that are open towards said main side faces 11; 21 and that are suitable for receiving the label protecting cover 110; 210. Each L-section groove has a floor 17B; 27B and a 10 side wall hollowed out in an open longitudinal groove 17C; 27C for snap-fastening the label-protecting cover 110; 210. Between the L-section grooves, the identifying portion 17; 27 forms a front facet 17A; 27A that is 15 defined on one side by the shoulder 16B; 26B. In the embodiments shown, the shoulder 16B; 26B continues sideways on either side of the facet 17A; 27A so as to join the floors 17B; 27B of said L-section grooves via rounded connecting fillets 16C; 26C. 20 As shown more particularly in Figures 3, 5, 8, and 9, the label-protecting cover 110; 210, which is made of transparent material, includes a front wall between two stringers 111; 211, whereby it is adapted to engage from the front in the L-section grooves of the identifying 25 portion 17; 27. Each of these stringers 111; 211 presents a rim at right angles projecting towards the other stringer and constituting teeth 112; 212 for snap-fastening in the longitudinal groove 17C; 27C recessed in the side wall of 30 the corresponding L-section groove of the identifying portion 17; 27. A top edge of the front wall of the label-protecting cover 110; 210, which edge extends transversely between the two stringers 111; 211, is provided with a notch 113; 35 213 that extends over practically the entire length of said edge.

9 In this example, the label-protecting cover 110; 210 is put into place frontally onto the identifying portion 17; 27 of the casing 10; 20, sandwiching the pull-tab 120; 220 between its front wall and the facet 17A; 27A of 5 said identifying portion 17; 27. While being put into place frontally, the stringers 111; 211 of the label-protecting cover 110; 210 splay apart from each other elastically by a small amount so as to enable the teeth 112; 212 they carry to snap-fasten in 10 the corresponding longitudinal groove 17C; 27C of the identifying portion 17; 27. The height of the stringers 111; 211 is no greater than the distance between the floors 17B; 27B of said L section grooves and the main portion of the front face 15 12; 22 of the casing 10; 20, and in practice it is less than said distance. The thickness of the stringers 111; 211 is no greater than the width of the L-section grooves in the identifying portion 17; 27, and in practice it is 20 slightly less than said width. Thus, once in place on the identifying portion 17; 27 of the casing 10; 20 of the modular electrical appliance, the label-protecting cover 110; 210 comes substantially flush with the front face 12; 22 and with 25 the main side faces 11; 21 of the casing 10; 20, being completely integrated in the outline of the casing 10; 20. To emphasize this integration, the side edge at the end of each stringer 111; 211, corresponding to the 30 shoulder 16B; 26B of the casing 10; 20, is rounded to match the connection filets 16C; 26C extending said shoulder 16B; 26B so as to match the curvature thereof closely. In the embodiment described, the other side edges at 35 the ends of the stringers 111; 211 are straight, however they could equally well be rounded in the opposite direction to the first side edges.

10 When the label-protecting cover 110; 210 is snap fastened onto the identifying portion 17; 27 of the casing 10; 20, its front wall covers the facet 17A; 27A of said identifying portion 17; 27. 5 The reception housing defined by the inside face of the label-protecting cover 110; 210, by the facet 17A; 27A of the identifying portion 17; 27, and by the shoulder 16B; 26B opens to the outside via a slot in the corresponding side face of the casing 10; 20, at the side 10 of the label-protecting cover 110; 210 that is opposite from the shoulder 16B; 26B of said casing 10; 20. The slot is defined between the edge of the notch 113; 213 of the label-protecting cover 110; 210 and the identifying portion 17; 27. 15 The reception housing as defined in this way between the label-protecting cover 110; 210 and the identifying portion 17; 27 of the casing 10; 20 houses the pull-tab 120; 220. The pull-tab 120; 220 is in the form of a plate 127; 20 227 having a front face 120A; 220A adjacent to a rib 122; 222 that defines a housing 123; 233 for receiving a label (not shown). The plate 127; 227 is of width and height that are slightly smaller respectively than the (between the 25 facing inside faces of the stringers 111; 211) and the height of the label-protecting cover 110; 210. In the example shown in Figure 5, the plate 127 presents a shape that is square, whereas in the example shown in Figure 9, the plate 227 is rectangular in shape. 30 Advantageously, in order to facilitate removing the label from the label housing 123; 223 defined by said rib 122; 222 on the front face 120A; 220A of the plate 127; 227, the rib 122; 222 presents a local reduction in height. 35 Here, said rib 122; 222 presents a reduction in height at two different locations extending over the same distance along two parallel sides of the plate 127; 227.

11 More precisely, in the embodiment shown, said rib 122; 222 is locally interrupted at the two corresponding locations. In addition, as shown in Figures 3, 5, 8, and 9, the 5 plate 127; 227 includes a notch 124; 224 in the position where said rib 122; 222 is interrupted, the notch opening out into the side of said plate 127; 227. The plate 127; 227 thus has two notches 124; 224 that are placed in two parallel side edges. These notches 124; 224 enable the 10 installer to take hold of the label between two fingers so as to extract it very easily from the label housing 123; 223 defined on the front face of the pull-tab 120; 220. Preferably, each modular electrical appliance shown 15 has means for guiding the movement in translation of the pull-tab 120; 220 in its reception housing, which means act between said identifying portion 17; 27 of the casing 10; 20 and the pull-tab 120; 220. In this example, the guide means comprise firstly, 20 on the rear face 120B; 220B of the plate 127; 227, one or two pairs of parallel ribs 125; 225, and secondly on said identifying portion 17; 27, one or two grooves 17D; 27D each having a pair of ribs 125; 225 sliding therein. In the example shown in Figure 3, said identifying 25 portion 17 has a central groove 17D set back in its facet 17A, the central groove having a U-shaped section and extending parallel to said L-section grooves from the shoulder 16B to the opposite edge of said facet 17A. This groove 17D slidably receives a pair of parallel ribs 30 125 that project from the rear face 120B of the plate 127. In the example shown in Figure 8, said identifying portion 27 includes two U-section grooves 27D set back in its facet 27A, each of which grooves extends along an L 35 section groove from the shoulder 26B to the opposite edge of said facet 27A. These two grooves 27D slidably 12 receive two pairs of parallel ribs 225 projecting from the rear face 220B of the plate 227. In the embodiments shown in the various figures, the means for blocking the pull-tab 120; 220 in its retracted 5 position or in its position projecting from the casing 10; 20 comprise at least one tooth 126; 226 that projects from the rear face 120B; 220B of the pull-tab 120; 220 together with at least one housing for receiving each tooth 126; 226 defined between a ramp 19; 29 and a stop 10 18, 16B; 28, 26B facing it on the identifying portion 17; 27 of the casing 10; 20. In the example shown in Figures 3 to 5, the pull-tab 120 has a tooth 126 on its rear face 120B, which tooth is situated close to the bottom transverse edge of the pull 15 tab 120. This tooth 126 extends between the two parallel ribs 125, transversely relative thereto. In correspondence therewith, the bottom of the central groove 17D in the identifying portion 17 of the casing 10 is provided firstly with a ramp 19 and a facing stop 18 20 located close to the top edge (opposite from the shoulder 16B) of the identifying portion 17 so as to block the pull-tab 120 in its position projecting from the casing 10, and secondly with another ramp 19 placed facing the shoulder 16B (forming a stop) for blocking the pull-tab 25 120 in the retracted position fully engaged inside its reception housing. In the example shown in Figures 8 and 9, the pull tab 220 carries two teeth 226 on its rear face 220B, the teeth being situated close to the bottom transverse edge 30 of the pull-tab 220. Each tooth 226 extends between the two parallel ribs 225 of a pair of ribs, transversely relative thereto. In correspondence therewith, the bottom of each groove 27D in the identifying portion 27 of the casing 20 is provided firstly with a ramp 29 with 35 a facing stop 28 located close to the top edge (opposite from the shoulder 26B) of the identifying portion 27 in order to block the pull-tab 220 in its position 13 projecting from the casing 20, and secondly with another ramp 29 placed facing the shoulder 26B (that forms a stop) for blocking the pull-tab 220 in the retracted position when fully engaged inside its reception housing. 5 Each ramp 19; 29 presents two opposite inclined slopes 19A; 29A united by a rounded top 19B; 29B (see Figures 4 and 8) to constitute an obstacle that each tooth 126; 226 of the pull-tab 120; 220 can be moved past on being pulled or pushed by the installer. 10 Thus, when the pull-tab 120; 220 is placed in the retracted position, its tooth 126; 226 is engaged in the tooth housing defined by the ramp 19; 29 and the shoulder 16B; 26B of the casing 10; 20. In this way, the pull-tab 120; 220 is prevented from moving in its reception 15 housing and the various handling operations to which the modular electrical appliance may be subjected do not run any risk of causing the pull-tab 120; 220 to move out from its reception housing. If the installer desires to change or position an 20 identifying label on the identifying portion of the casing 10; 20 of the modular electrical appliance, then it suffices to pull the pull-tab 120; 220 from its retracted position outwards from the reception housing so as to bring it into its projecting position. 25 By exerting a small amount of traction on the pull tab, the installer causes each tooth 126; 226 of the pull-tab 120; 220 to go past said ramp 19; 29 placed facing the shoulder 16B; 26B, thereby enabling the pull tab 120; 220 to slide inside its reception housing until 30 each tooth 126; 226 goes past the other ramp 19; 29 and becomes blocked against the stop 18; 28 positioned close to the top edge of the identifying portion 17; 27 of the casing opposite from the shoulder 16B; 26B. The pull-tab 120; 220 is thus prevented from moving 35 when it is in its position projecting from the casing 10; 20 and therefore the installer has both hands free for easily removing and/or positioning a label from or in the 14 label housing 123; 223 defined on the front face 120A; 220A of the pull-tab 120; 220. Thereafter, the installer can push the pull-tab 120; 220 into its reception housing so as to cause it once 5 more to be held in its retracted position fully engaged in said reception housing with the label protected by the label-protecting cover 110; 210. By exerting a small amount of thrust on the pull-tab 120; 220, the installer causes each tooth 126; 226 10 thereof to go past the ramp 19; 29 placed close to the top edge of the identifying portion 17; 27 opposite from the shoulder 16B; 26, thereby enabling said pull-tab 120; 220 to slide inside its reception housing until each tooth 126; 226 goes past the other ramp 19; 29 to become 15 blocked against the shoulder 16B; 26B of the casing 10; 20.

Claims

1. A modular electrical appliance comprising a casing (10; 20) having a front face provided with an identifying portion (17; 27), a label-protecting cover (110; 210) 5 that co-operates with said identifying portion to define a reception housing that is open to the outside via a slot, and a pull-tab (120; 220) that is mounted to move in translation in said reception housing through the slot, said pull-tab (120; 220) including a rim (121; 221) 10 along one side, said rim being adapted to close said slot at least in part when the pull-tab (120; 220) is fully engaged in said reception housing, the appliance being characterized in that it includes blocking means (116, 19, 18; 126, 29, 28) for preventing the pull-tab (120; 15 220) from moving relative to the casing (10; 20) when the pull-tab is in a projecting position outside said reception housing.

2. An electrical appliance according to claim 1, 20 characterized in that it includes blocking means (126, 19, 16B; 226, 29, 26B) for preventing the pull-tab (120; 220) from moving when the pull-tab is in a retracted position in which it is fully engaged inside said reception housing. 25

3. An electrical appliance according to any preceding claim, characterized in that said blocking means (126, 19, 18, 16B; 226, 29, 28, 26B) act between the pull-tab (120; 220) and the casing (10; 20). 30

4. An electrical appliance according to claim 1 or claim 2, characterized in that said blocking means act between the pull-tab and the label-protecting cover. 35

5. An electrical appliance according to any preceding claim, characterized in that said blocking means (126, 16 19, 18, 16B; 226, 29, 28, 26B) are reversible snap fastener means.

6. An electrical appliance according to any one of claims 5 1 to 4, characterized in that said blocking means are friction means.

7. An electrical appliance according to any one of claims 1 to 4, characterized in that said blocking means are 10 jamming means.

8. An electrical appliance according to any one of claims 1 to 4, characterized in that said blocking means are releasable catch means. 15

9. An electrical appliance according to claim 3, characterized in that the blocking means comprise at least one tooth (126; 226) projecting from the rear face (120B; 220B) of the pull-tab (120; 220) and at least one 20 housing for the tooth, this housing being defined between a ramp (19; 29) and a stop (18, 16B; 28, 26B) placed facing the ramp on the identifying portion (17; 27) of the casing (10; 20). 25

10. An electrical appliance according to the preceding claim, characterized in that each ramp (19; 29) presents two opposite inclined slopes (19A; 29A) united via a rounded top (19B; 29B). 30

11. An electrical appliance according to any preceding claim, characterized in that the pull-tab (120; 220) is in the form of a plate (127; 227) having a front face (120A; 220A) surrounded by a rib (122; 222) that defines a housing (123; 223) for a label, the rib (122; 222) 35 presenting a local reduction in its height. 17

12. An electrical appliance according to the preceding claim, characterized in that said rib (122; 222) presents reduced height at two different locations, each occupying the same distance along two parallel sides of said plate 5 (127; 227).

13. An electrical appliance according to either one of the two preceding claims, characterized in that said rib (122; 222) is locally interrupted. 10

14. An electrical appliance according to the preceding claim, characterized in that the plate (127; 227) includes a notch (124; 224) where said rib (122; 222) is interrupted, the notch opening out into the edge of said 15 plate (127; 227).

15. An electrical appliance according to any preceding claim, characterized in that it includes guide means (17D; 125; 27D, 225) for guiding the movement of the 20 pull-tab in translation in its reception housing, which guide means act between the identifying portion (17; 27) and the pull-tab (120; 220).

16. An electrical appliance according to the preceding 25 claim, characterized in that said guide means include at least one groove (17D; 27D) in said identifying portion (17; 27), the bottom of the groove having a portion of said blocking means provided therein.