EP1559123A1

EP1559123A1 - Auxiliary contact block providing temporary contact

Info

Publication number: EP1559123A1
Application number: EP03789463A
Authority: EP
Inventors: Alain Ortega
Original assignee: ABB Entrelec SAS
Current assignee: ABB France SAS
Priority date: 2002-11-08
Filing date: 2003-11-07
Publication date: 2005-08-03
Anticipated expiration: 2023-11-07
Also published as: WO2004044940A1; ATE321353T1; FR2847072A1; CN1711619A; DE60304215D1; WO2004044940A9; CN100336146C; EP1559123B1; FR2847072B1; DE60304215T2

Abstract

The auxiliary contactor has a container (5) enclosing fixed auxiliary contacts accessible from outside and an auxiliary slide (100). The auxiliary slide is made in two parts, a leading (110) and following (120) section. When the first part slides in a first direction, the second part is slid in a second perpendicular direction during part of the movement.

Description

AUXI IAIRE CONTACT BLOCK TEMPORARY CONTACT

The present invention relates to an auxiliary contact block with temporary contact intended to be implemented with an electrical contactor.

One or more auxiliary contact blocks is or are usually mounted either on the front face or on a lateral face of a contactor. Each auxiliary contact block includes at least one contact, called an auxiliary contact, which is part of an auxiliary circuit the opening or closing of which is controlled as a function of the state, open or closed, of the contactor.

In a manner known per se, such an auxiliary contact block is mounted on the electrical contactor so that its slide, called auxiliary slide, is driven by the slide of said contactor. The auxiliary contact or each auxiliary contact is often composed of two fixed contacts carried by a housing and electrically connected to two terminals accessible from outside the housing, and a mobile bridge carried by the auxiliary slide, said mobile bridge carrying two contacts intended to be brought into contact with the fixed contacts. The movable bridge is arranged peφendicular to the slide and the two fixed contacts are arranged in a plane parallel to said movable bridge.

The auxiliary slide of the auxiliary block on which the movable bridge is mounted is linked in movement to the contactor slide so that the movement of the assembly constituted by the contactor slide and the auxiliary slide takes place longitudinally in a direction perpendicular to the fixed contact line.

This arrangement usually implemented has certain drawbacks: - it is necessary to adapt the travel of the auxiliary slide to that of the contactor slide or to introduce elastic means allowing the continuation of the travel of the contactor slide after the contacting of the auxiliary contacts, - the implementation of elastic means in the displacement of the slides causes the appearance of untimely rebounds of the movable bridge which, on the one hand degrade the quality of the auxiliary contacts, and on the other hand do not make it possible to know the exact moment of closing said auxiliary contacts. Auxiliary blocks are also frequently used in installations comprising a capacitive load circuit intended to improve the cosine phi of an installation. In such devices, called temporary contact devices, the auxiliary contacts are intended to supply one or more resistors (or inductors) arranged in parallel with the main contacts and must be closed before the main contacts of the contactor, then open. as soon as the said main contacts are closed. We thus obtain the insertion for a very short time of the resistors or inductors between the moment of closing of the auxiliary contacts and their short-circuiting by the main contacts, which makes it possible to reduce the current peak when the main contacts are closed.

Such temporary contact auxiliary contact blocks are usually of very complicated conformation requiring means allowing the uncoupling of the main slide and the secondary slide during the closing of the contacts and the re-coupling during the opening of the main contacts. Such temporary contact blocks are therefore difficult to develop and not always reliable. The present invention seeks to propose an auxiliary contact block with temporary contact which does not have the drawbacks of devices usually used and which can easily be adapted to constitute a device with temporary contact. To this end, the invention relates to an auxiliary contact block with temporary contact, of the type comprising a housing containing at least one fixed auxiliary contact accessible from outside the housing and an auxiliary slide carrying at least one movable auxiliary contact capable of being brought temporarily into contact with said fixed auxiliary contact to modify the state of the auxiliary contact, said auxiliary contact block being able to be mounted on an electric contactor so that the auxiliary slide is driven by a main slide of said electric contactor, characterized in that that: a) the auxiliary slide is made in two parts respectively leading and driven; b) the driving part carries hooking means by which it is capable of being hooked to the main slide and driven by it; c) the driven part carries the movable auxiliary contact, and is connected to the driving part by connecting means comprising at least one pin and a groove, said pin being able to traverse said groove during the movement of the leading part, said groove forming a closed loop such that when the driving part is moved in a first direction by the main slide, said driving part forces the driven part to move in a second direction substantially perpendicular to the first direction during a first part of the travel of moving the driving part in the first direction to temporarily close the auxiliary contact, and the driven part moves in a direction opposite to the second direction to open said auxiliary contact during a final part of the travel movement of the driving part in the first direction, and such that when said driving part is then moved in a direction opposite to the first direction , it causes zero or negligible displacement of the driven part and does not modify the state of the mobile auxiliary contact.

US-A-3,435,389 describes an assembly consisting of a main electrical contactor and at least one auxiliary contact block, the slider of which is movable in a direction perpendicular to the direction of movement of the slider of the main electrical contactor. However, in this document, the auxiliary contact block is not of the temporary contact type and the auxiliary slide is in one piece. The auxiliary contact block according to the invention is also remarkable in that:

- The pin is carried by said driving part and the groove is formed in the driven part;

- The groove successively comprises a first part which extends obliquely to said first direction, a second part parallel to said first direction, a third part which extends perpendicularly to said first direction in a direction such that said first and third parts of the groove are on the same side of the second part of the groove, and a fourth part which extends substantially parallel to said first direction and which connects to the first part of the groove so as to close said loop; - The groove successively comprises a first part which extends obliquely to the first direction, a second part substantially perpendicular to said first direction, followed by a third part which extends substantially parallel to said first direction and which is connected to the first part of the groove so as to close said loop;

- The part of the groove, which is perpendicular or substantially perpendicular to the first direction, has a width greater than that of the other parts of the groove; - The driven part of the auxiliary slide moves in the direction opposite to said second direction under the action of an elastic return means;

said connection means comprise several grooves which are formed in one of said driven and driving parts of the auxiliary slide and which have different shapes and / or dimensions corresponding to given values different from the stroke of said driving part in said first direction and at least one desired value of the stroke of said piece driven in said second direction, and the other of said driven and driving pieces having several holes which are respectively associated with said grooves, so that when said pin is inserted in a hole selected from said orifices, the pin is engaged with a corresponding selected groove from said grooves.

Thus, the auxiliary contact block can be installed on electrical contactors whose respective main sliders have strokes of different lengths for closing the main contacts. For this, it suffices to select each time, as the case may be, from said orifices, an appropriate orifice associated with a groove whose shape and / or dimensions correspond to a value of the travel of the driving part of the auxiliary slide appropriate to the length of the travel of the main slide of the electrical contactor on which it is desired to install the auxiliary contact block. The invention will be better understood from the description which follows given by way of nonlimiting example with reference to the appended drawings in which:

FIG. 1 is a schematic sectional view of an auxiliary slide intended to equip an auxiliary contact block with temporary contact according to a first embodiment of the invention,

- Figures 2a to 2d are side views showing the movement of the driven part of the auxiliary slide of Figure 1 when closing a main contactor equipped with said auxiliary contact block, - Figure 3 is a side view in perspective showing, in exploded view, a concrete embodiment of an auxiliary contact block with temporary contact according to a second embodiment of the invention,

FIG. 4 is an exploded perspective view of the auxiliary contact block of FIG. 3, seen from the rear of the representation of FIG. 3,

FIGS. 5a to 5d show the displacement of the auxiliary slide equipping the auxiliary contact block of FIGS. 3 and 4 when the main contactor is closed,

- Figures 6a to 6d show the displacement of the auxiliary slide fitted to the auxiliary contact block of Figures 3 and 4 when the main contactor is opened.

FIGS. 1 and 2 show only the auxiliary slide 1 intended to equip an auxiliary contact block according to the invention. In a manner known per se, and as will be described in more detail with reference to FIGS. 3 and 4, an auxiliary contact block is formed from a housing comprising at least one fixed auxiliary contact 30 accessible from outside the housing and at at least one corresponding movable auxiliary contact 31 carried by the auxiliary slide 1, in a window 23 thereof, and intended to be brought into contact with said fixed auxiliary contact 30 to close an auxiliary circuit. Said movable contact 31 is permanently pushed back towards the fixed contact 30 by a retaining spring 32 positioned in the window 23. Said auxiliary contact 30 is closed or opened depending on the state of the contact or main contacts of the electrical contactor on which is mounted the auxiliary contact block.

To this end, the auxiliary slider 1 is hooked to the so-called main slider of the electrical contactor by attachment means such as the clamp 11 shown in FIG. 1.

According to the invention, the auxiliary slide 1 consists of two parts, namely a driving part 10 and a driven part 20.

The driving part 10 carries the attachment means 11 by which it is hooked to the main slide, not shown, and driven by the latter during its vertical reciprocating movements in the direction of the double arrow F / O, the letter F denoting the direction of closing of the main contact (s), while the letter O indicates the direction of opening of the main contact (s).

The driven part 20 is driven by the driving part 10 and carries at least one movable auxiliary contact 31 visible in FIGS. 2a to 2d.

Said movable auxiliary contact 31 is positioned in a window 23 of the driven part 20 and arranged perpendicular to said driven part

20. The auxiliary contact block can have one or more contacts Auxiliary. In the embodiment shown in Figures 1 and 2, the driven part 20 has three windows 23 in which can be positioned movable auxiliary contacts 31, only one such fixed auxiliary contact 31 being shown in Figures 1 and 2. The part driven 20 comprises at least one groove 22, preferably two grooves 22 hollowed out on either side of said driven part 20, in each face thereof. As can be seen in FIGS. 2a to 2d, said groove 22 forms a closed loop which is produced in four parts, namely successively a first oblique part 24, a second part 26 parallel to the direction F / O of movement of the main slide and of the leading part 10 connected to the latter, a third part 27 perpendicular to the direction F / O and a fourth part 28 which is parallel or substantially parallel to the direction F / O and which is connected to the upper end of the first part 24 of groove 22 to close the loop. The expression "parallel or substantially parallel" used here in connection with the fourth part 28 of the groove means that, when the pin 12 runs from bottom to top said part 28, said pin 12 causes a displacement of the driven part 20 which is zero, negligible or in any case insufficient to cause a change of state of the auxiliary contacts 30-31. The third part 27 of the groove 22 has a greater width than those of the other parts 24, 26 and 28 of the groove 22.

The driven part 20 is connected to the driving part 10 by at least one pin 12 carried by said driving part 10 and disposed in the groove 22 of the driven part 20. Said pin 12 is intended to traverse said groove 22 during the movement of the driving part 10 driven by the main slide. In the embodiment shown in FIGS. 1 and 2, the driven part 20 has two grooves 22 in each of which is engaged a pin 12 of the driving part 10.

The driving part 10 is preferably guided in the housing of the auxiliary contact block by guide means arranged in such a way that said driving part can only move in the direction F / O of movement of the main slide of the contactor. Similarly, the driven part 20 is mounted in the housing of the auxiliary contact block so that it can only move in a direction F l / Ol perpendicular or substantially perpendicular to the direction F / O of movement of the main slide. contactor. The expression "substantially perpendicular", in the present context, means that the directions F l / Ol and F / O form an angle of 90 ° ± 10 ° between them. We will now describe the operation of the auxiliary contact block comprising the auxiliary slide shown in FIGS. 1 and 2.

When the device is at rest, that is to say when the main contactor is open, the main slide is in its highest position and keeps the driving part 10 of the auxiliary slide 1 in the high position. The two parts 10 and 20 of the auxiliary slide 1 are then positioned as shown in FIGS. 1 and 2a, each pin 12 being near the upper end of the oblique first part 24 of the corresponding groove 22. During the closing of the main contactor, the main slider pulls the driving part 10 from the auxiliary slider 1 in the direction of the arrow F, so that each pin 12 moves downwards in the first oblique part 24 of the groove 22 corresponding. The inclination of the first oblique part 24 of the groove 22 causes the displacement of the driven part 20 in the direction FI perpendicular to F, against the return spring 4 bearing against a fixed wall (not shown) of the contact block housing auxiliary. The displacement of the driven part 20 in the direction FI is visible in FIGS. 2a to 2d in which the vertical line ZZ along which the pins 12 move is shown by a dashed line.

While each pin 12 traverses the first oblique part 24 of the corresponding groove 22 and forces the driven part 20 to move in the direction FI, the movable auxiliary contact 31 approaches the fixed auxiliary contact 30 and comes into contact with the latter (Figure 2b). During the next movement of the driven part 20 in the direction FI, said driven part continues to compress the spring 4 and compresses the spring 32 which keeps the movable auxiliary contact 31 pressed against the fixed auxiliary contact 30.

In the intermediate position shown in Figure 2c, the spring 32 exerts maximum pressure on the closed auxiliary contacts 30-31, while the stroke of the main slide is not finished. In this intermediate position, each pin 12 is disposed at the upper end of the second part 26 of the groove 22.

During the further movement of the main slide, each pin 12 moves in the second part 26 of the corresponding groove 22. This second part 26 of the groove 22 being parallel to the direction F of movement of the main slide, the driven part 20 of the auxiliary slide 1 remains stationary and the auxiliary contacts 30-31 remain closed while the main contacts (not shown) of the contactor in turn close. As soon as the pin 12 traversing the part 26 of the groove 22 arrives at the upper edge of the part 27 of the said groove, the driven part 20 of the auxiliary slide 1 is pushed back in the direction 01 by the spring 4 and thus causes the reopening of the auxiliary contacts 30-31. This occurs after the main contacts of the electrical contactor are closed, but before the end of the vertical downward travel of the pin 12 corresponding to the end of the travel of the main slide and the driving part 10 of the auxiliary slide 1 (Figure 2d). However, as the part 27 of the groove 22 has a greater width, the vertical downward movement of the main slider, of the driving part 10 of the auxiliary slider 1 and of the pin 12 is not hampered by the lower edge of the part 27 of groove 22.

Conversely, during the opening of the electrical contactor, the main slide moves in the direction O and first pushes the driving part 10 of the auxiliary slide 1 in this direction, which has the effect of moving each pin 12 in the fourth part 28 of the corresponding groove 22, arranged parallel to the direction O, without moving the driven part 20. During this phase, the main contacts of the electrical contactor open, while the auxiliary contacts 30-31 remain open.

The arrangement according to the invention according to which the auxiliary slide 1 is produced in a driving part 10 and a driven part 20 connected to each other so that the driving part 10 moves in the same direction F / O as the main slide, while the driven part 20 moves in a direction F l / Ol perpendicular to the direction of movement of the driving part 10, makes it possible to separate the movement necessary for closing the main contact from the movement necessary for closing the contact auxiliary. Knowing the value of the displacement H necessary for the closing of the main contacts and the value of the displacement d necessary for the closing of the auxiliary contacts, it is possible to determine the shape, the length and the inclination of the part 24 of the groove 22. When the 'we try to close the auxiliary contacts before the main contacts, the complete closure of the auxiliary contacts takes place at the end of a stroke h that Ton can define the main slide.

The auxiliary contact block according to the invention does not have the drawbacks described above and due to the use of springs allowing the movement of the main slide to continue when the auxiliary slide is at the end of its travel.

In the embodiment described above, the second part 26 of the groove may possibly have a zero length, that is to say that in this case the parts 24 and 27 of the groove 22 are directly connected to one to the other.

Figures 3 to 6 show a concrete embodiment of an auxiliary unit according to the invention in order to constitute a so-called temporary contact unit.

As shown in Figures 3 and 4 and in a manner known per se, the auxiliary contact block according to the invention consists of a housing 5 closed by a cover 51. Openings 52 of the housing 5 and tongues 55 carrying lugs 54 of the cover 51 secures said cover 51 to the housing 5 by snap-fastening. The box 5 shown in Figures 3 and 4 carries means 50 for hooking on the front face of the electrical contactor not shown in the drawing. The housing 5 carries fixed auxiliary contacts 300 which are inserted into slots 53 so that one of their ends is accessible from the outside of said housing 5.

As described above, the auxiliary slide 100 of the auxiliary contact block is made in two parts, a driving part 110 which can be attached to the main slide of an electrical contactor not shown in the drawing by the hooking means 111, and a part driven 120 which carries at least one movable auxiliary contact 310 disposed in a window 123 with interposition of a spring 320 and at least one return spring 400.

The driving part 110 of the auxiliary slide 100 has ribs 115, for example of T-section, intended to slide in guide grooves not visible in the drawing formed on the internal face of the housing 5. The connection between the driving part 110 and the driven part 120 of the auxiliary slide 100 is produced in the following manner. The driven part 120 has a wall 125 comprising at least one groove 122 while the driving part 110 comprises a wall 113, parallel to the wall 125, carrying a pin 112 capable of engaging in the groove 122. As visible on the Figure 3, the wall 113 has three holes

114, identified by a marking, into which the pin 112 can be inserted.

As visible in FIG. 4, three grooves 122 are formed in the wall 125 around three bosses 129 serving as cams. Referring to FIG. 5d, it can be seen that each groove 122 has a first oblique part 124, a second part 127 which is generally perpendicular to the direction F / O of movement of the main slide and which extends under the corresponding boss 129 , and a third part 128 which is generally parallel to the direction F / O movement of the main slide and which extends on one side of the boss 129. In other words, in the embodiment of FIGS. 3 to 6, each groove 122 does not have a part corresponding to the part 26 of the groove 22 of the mode of Figures 2a to 2d. As can be seen in FIGS. 4 to 6, the bosses 129, and therefore also the grooves 122, have different shapes and dimensions corresponding to different strokes necessary for closing the main contacts and the auxiliary contacts.

The choice of the orifice 114 in which the pin 112 is inserted is made according to the stroke necessary for the closing of the main and auxiliary contacts s. Each of the possible positions of the pin 112 corresponds to a groove 122 in the driven part 120.

FIGS. 5a to 5d illustrate the relative movement of the driving part 110 and the driven part 120 of the auxiliary slide 100 during the closing of the main contacts. Figures 6a to 6d are figures similar to Figures 5a to 5d illustrating the relative movement of the driving part 110 and the driven part 120 of the auxiliary slide 100 during the opening of the main contacts. As in Figures 2a to 2d, a vertical axis XX is shown in Figures 5 and 6 in order to better visualize the movements of the driven part 120 in the direction F l / Ol.

At rest, main and auxiliary contacts open, the driving part 110 and the driven part 120 of the auxiliary slide 100 are in the relative position shown in FIG. 5a and the pin 112 is located at the upper end of the first oblique part 124 of groove 122.

During the movement of the main slide, and therefore of the driving part 110 of the auxiliary slide 100, in the direction F, the pin 112 moves along the first oblique part 124 of the groove 122 (FIGS. 5b and 5c) which has the effect of moving the driven part 120 in the direction FI of closing of the auxiliary contacts 300-310. In the position shown in FIG. 5c, the pin 112 is at the lower end of the first oblique part 124 of the groove 122, the auxiliary contacts are closed as well as the main contacts.

During the movement corresponding to the passage from the position shown in Figure 5c to that shown in Figure 5d, the main slide and the driving part 110 of the secondary slide 100 move in the direction F over a short distance c.

During this stroke c, the main contacts already closed are put in compression by springs not shown and the pin 112 escapes from the first oblique part 124 of the groove 122 to enter the second part 127 of said groove 122. The pin 112 no longer being held laterally, the return spring 400 pushes the driven part 120 in the direction 01 of opening the auxiliary contacts. Thus, just after closing the main contacts, the auxiliary contacts open. It is of course possible to conform the boss 129 so as to create between the parts 124 and 127 of the groove 122 an intermediate part parallel to the direction F / O of movement of the main slide to maintain the auxiliary contacts closed for a predetermined period of time. that the main contacts close.

The arrangement shown in Figure 6a is identical to that shown in Figure 5d, but the main slide starts its race in the direction O for the opening of main contacts. During this opening stroke, the driving part 110 of the auxiliary slide 100 is driven in the direction O and the pin 112 moves in the third part 128 of the groove 122.

This third part 128 of the groove 122 being generally parallel to the direction O of movement of the main slide and of the driving part 110 of the auxiliary slide, the driven part 120 then remains stationary while the driving part 110 moves in the direction O.

The third part 128 of the groove 122 preferably ends, and as shown in FIGS. 5-6, by a slightly oblique portion so that the driven part 120 of the auxiliary slide 100 is moved over a short stroke in the direction Ol opening of the auxiliary contacts, 300-310, to the relative position shown in FIG. 6c, while slightly compressing the spring 401. Thanks to this arrangement, when the main channel reaches the end of its opening stroke and the driving part 110 of the auxiliary slide 100 also reaches its extreme position, the pin 112 leaves the third part 128 of the groove 122 and is no longer held laterally which allows the return spring 401 to slightly move the driven part 120 in the direction FI of closing the auxiliary contacts 300-301, without these closing, to bring the pin 112 to the upper end of the first part forgotten that 1 24 of the groove 122, in the rest position shown in Figure 6d which corresponds to Figure 5a. As before, the dimensions and shapes of each of the parts of the groove 122 can be modified as a function of the strokes of the main and auxiliary contacts and of the times sought for the closing and opening of each of these contacts. The auxiliary contact block according to the invention can thus be modified very simply, by a simple adaptation of the shape of the groove 22 or 122 to constitute a very reliable temporary contact block since it is not necessary to provide means for uncoupling and re-coupling the main and auxiliary slides.

The invention obviously applies to all types of contactors and auxiliary contact blocks whatever the number of contacts carried by each. We will not depart from the invention by modifying the auxiliary slide of the embodiment of FIGS. 1 and 2 to provide several grooves 22 of different shapes and dimensions corresponding to different positions of the pin (s) 12, or by modifying the slide of FIGS. 3 to 6 so as to provide only a single groove 122 and a single position of the pin 112.

Similarly, each auxiliary slide can have a groove and pin on one side or on two opposite faces.

Furthermore, although the exemplary embodiments show a pin carried by the driving part and a groove carried by the driven part, we will not depart from the invention by positioning the pin on the driven part and the groove on the driving part.

Furthermore, in the two embodiments described above, instead of having a groove 22 (122), having a part 27 (127) wider than the other parts 24, 26, 28 (or 124, 128) of the groove 22 (122), the part 27 (or 127) thereof could have the same width as the other parts and extend obliquely downward in a direction perpendicular or substantially perpendicular to the part 24 (or 124) of the groove 22 (or 122), so that the opening of the contacts auxiliary contact block is positively controlled by the part 27 (or 127) of the groove 22 (or 122).

Claims

1. Temporary contact auxiliary contact block, of the type comprising a housing (5) containing at least one fixed auxiliary contact (30, 300) accessible from the outside of the housing and an auxiliary slide (1, 100) carrying at least one movable auxiliary contact (31, 310) capable of being brought into temporary contact with said fixed auxiliary contact (30, 300) to modify the state of the auxiliary contact, said auxiliary contact block being capable of being mounted on an electrical contactor so that the auxiliary slider (1, 100) is driven by a main slider of said electrical contactor, characterized in that a) the auxiliary slider (1, 100) is made in two parts respectively driving (10, 110) and driven (20, 120 ); b) the driving part (10, 110) carries hooking means (11, 111) by which it is capable of being hooked to the main slide and driven by the latter; c) the driven part (20, 120) carries the movable auxiliary contact (31, 310) and is connected to the driving part (10, 110) by connecting means comprising at least one pin (12, 112) and a groove (22, 122), said pin (12, 112) being capable of traversing said groove (22, 122) during the movement of the driving part (10, 110) attached to the main slide, said groove forming a closed loop such that when the driving part (10, 110) is moved in a first direction (F) by the main slide, said driving part forces the driven part (20, 120) to move in a second direction (FI) substantially perpendicular to the first direction during a first part of the travel movement of the driving part (10, 110) in the first direction to temporarily close the auxiliary contact, and the part driven moves in a direction (01) opposite to the second direction (FI) to open said auxiliary contact during a final part of the movement of movement of the driving part in the first direction, and such that when said driving part (10, 110) is then moved in a direction (O) opposite to the first direction (F), it causes zero or negligible displacement of the driven part (20, 120) and does not modify the state of the movable auxiliary contact.

2. Block according to claim 1 characterized in that the pin (12, 112) is carried by said driving part (10, 110) and the groove (22, 122) is formed in the driven part (20, 120).

3. Block according to claim 1 or 2, characterized in that said groove (22) successively comprises a first part (24) which extends obliquely with respect to said first direction (F), a second part (26) parallel to said first direction (F), a third part (27) which extends peφendicularly with respect to said first direction (F) in a direction (FI) such that said first and third parts (24 and 27) of the groove (22 ) are on the same side of the second part (26) of the groove, and a fourth part (28) which extends substantially parallel to said first direction and which connects to the first part (24) of the groove so as to close said loop.

4. Block according to claim 1 or 2, characterized in that the groove (122) successively comprises a first part (124) which extends obliquely with respect to the first direction (F), a second part (127) substantially peipendicular to said first direction, followed by a third part (128) which extends substantially parallel to said first direction and which connects to the first part (124) of the groove (122) so as to close said loop.

5. Block according to claim 3 or 4, characterized in that the part (27 or 127) of the groove (22, 122), which is peφendicular or substantially peφendicular to the first direction (F), has a width greater than that of the other parts (24, 26, 28; 124, 128) of the groove.

6. Block according to any one of claims 1 to 5, characterized in that the driven part (20, 120) of the auxiliary slide (1, 100) moves in the direction (01) opposite to said second direction (FI) under the action of an elastic return means (4, 400).

7. Block according to any one of claims 1 to 6, characterized in that said connecting means comprise several grooves (122) which are formed in one of said driven and driving parts (120 and 110) of the auxiliary slide (100 ) and which have different shapes and / or dimensions corresponding to given different values of the stroke of said driving part (110) in said first direction and to at least one desired value of the stroke of said driven part (120) in said second direction, and the other of said driven and driving parts (120 and 110) having several holes (114) which are respectively associated with said grooves (122) so that, when said pin (112) is inserted in a selected hole among said holes (114), the pin (112) is engaged with a corresponding selected groove among said grooves (122).