Socket base with safety device

Abstract

 Socket base with a safety device, of the type which has a flat slide, with a "U"-shape with two arms which are parallel to one another, which can be guided in both straight flanges of the socket base in their movement of withdrawal from the rest position, whereas the slide itself is guided in opposition to these arms, by a projection or by projections guided by slots in the body itself of the socket base, the adjustment between the arms of the slide and the guide areas of the latter being sliding adjustment with the minimum play required in order to permit the displacement, whereas guiding of the projection(s) of the rear part of the slide on straight guides takes place with considerable lateral play, thus permitting initial pivoting of the slide around an axis which is perpendicular to the slide, when eccentric force is applied to the slide, thus locking the latter and preventing it from being displaced.

Description

[0001] The present invention relates to an electrical socket base with a safety device, which has significant characteristics of novelty and inventive activity compared with the type which is currently known.

[0002] The socket base which is the subject of the present invention belongs to the type of socket bases which have safety means to prevent introduction of foreign bodies into the contact holes or alveoli for the pins or spigots. These safety devices are designed to prevent accidents caused by the introduction of electrically conductive components into the interior of the socket bases, for example inadvertently, or by actuation by children etc.

[0003] In order to obtain safety characteristics in electrical socket bases, various devices have been made known throughout the years, which fulfil their function more or less satisfactorily. These devices are of very varied types, ranging from covers of various types which have to be opened in order to be able to carry out plugging in, to internal devices of the socket base, which keep the pin inlets closed in a situation of rest, and open only when these pins are introduced in order to make the connection.

[0004] The inventors have observed that most of the socket devices currently available which are provided with safety devices, have the disadvantage that it is possible to open the device by acting on only one of the inlets for the pins. In other words, it is possible to access only one of the holes of the socket base by means of an electrically conductive object, thus permitting contact which could be the cause of accidents.

[0005] The object of the present invention is to provide an electrical socket base which is provided with a device which has safety characteristics such that it is not possible to penetrate the inlet of any of the contact alveoli in order to accommodate the contact pins, by acting on only one of these alveoli. In other words, the object is to provide a safety device which in order to be opened, requires balanced and simultaneous actuation of both contact alveoli, since if this action is carried out on only one of the alveoli, it is not possible to gain access to the internal contacts, and thus accidents which are possible at present can be avoided.

[0006] In order to achieve these objectives, the socket base which is the subject of the present invention is of the type which has a gliding or sliding part, which is connected in the interior of the socket base, and is subjected to the action of antagonistic springs which maintain this slide opposite the inlets for the pins, such that the inlet of the corresponding alveoli is closed, but opening takes place automatically when a male-type plug is presented and introduced, since the pressure of the pins of the latter gives rise to opening of the safety slide. This type of slide is known from European patent application 94301773.

[0007] The present invention is based on the principles described in the aforementioned patent, and facilitates the means wherein the slide can be displaced only when simultaneous, balanced actuation takes place by the male plug in the two contact alveoli, but displacement of this slide is prevented if the actuation takes place in only one of these alveoli.

[0008] The present invention thus comprises an assembly formed by the cover of the socket base, and a slide with two arms which is accommodated in the latter, such that this slide is guided with a specific amount of play, and can strike against some fixed stops, such that if an eccentric thrust action is produced, in other words on only one of the alveoli for the contact pins, this slide is displaced slightly and undergoes slight rotation, which makes a fixed stop of the aforementioned cover intervene relative to a part of this slide, such that the latter cannot continue its displacement, and the inlet cannot be penetrated in order to establish contact in the socket base. However, if actuation takes place simultaneously on both introduction apertures of the contact pins, in other words in the event of a correct manoeuvre of introduction of a male plug, balanced thrust takes place on the aforementioned slide, which releases simultaneously the two inlet apertures for the contact pins, thus allowing connection by plugging in to take place. To improve the abutment action of the slide on the fixed parts of the cover a system of a double stop is established: from one side the arms of the slide abut on some fixed steps of the cover of the socket base and, from the other side, some hook-like portions of the internal part of a lengthwise groove of the rear projection of the slide will abut on one or the other of the two sides of a V form indentation at the end of a rib of the cover, which is located inside of the groove of the slide. Thus, the abutment position for each of the sides is obtained in a double form as previously explained.

[0009] In order to prevent possible introduction of conductive components into the inlet apertures of the socket base when the slide is in the safety stop position, in other words when the slide has been actuated eccentrically, the separation between the rear edge of the slide and the edge of the inlet apertures for the pins, is designed to be greater than the path to be travelled by the stop parts of the slide on the corresponding reception area of the socket cover. By this means, it is ensured that if the slide is locked because eccentric force has been exerted on it, in the locking position the inlet apertures for the pins continue to be closed, and do not permit insertion of electrically conductive components.

[0010] At the same time, in order to obtain better centring of the ends of the slide in which there exist the parts for contact with the stop areas, in order to obtain the safety locking, the opposite areas both of the contact parts of the slide, and of the reception areas of the cover of the socket base, have slight inward inclination which tends to produce a specific transverse force of closing the arm which has made contact with the slide.

[0011] In order to assist understanding, by way of non-limiting example there are attached some figures which correspond to an embodiment of the present invention.

Figure 1 is a view of the interior of the cover of a socket base with a safety device, according to the present invention;

Figure 1 bis is a detail of the end of one of the arms of the slide, showing its angular position relative to the fixed stop area of the socket base;

Figures 2 and 3 both show cross-sections through the planes indicated;

Figure 2 bis shows a detail in cross-section of the relative position of the end of a strip relative to the slide;

Figure 4 is a plan view of the closing cover of the socket base;

Figure 5 is a cross-section through the plane indicated, showing the springs which act on the internal contact pins;

Figure 6 is a plan view of the slide of the safety device;

Figures 7 and 8 are both cross-sections of details of the slide, through the planes indicated;

Figure 9 is a view from below of the slide itself;

Figure 10 is a plan view of the slide;

Figure 11 is a detail in cross-section of a structural variant of the slide;

Figure 12 is a cross-section through the plane indicated in figure 11;

Figure 13 is a plan view of a closing cover for connection pins of the flat type; and

Figures 14 and 15 are both details in cross-section through the planes indicated.

Figure 16 shows a similar view as that of Figure 1, showing the double stop position.

Figure 17 is a view of the cover showing the arrangement and the structure of the rib carrying the V indentation for the double stop.

Figure 18 is a perspective view of the slide showing the inclined planes and and lengthwise groove for the second stop.

[0012] The socket base with a safety device according to the present invention comprises a closing cover 1, which in its interior accommodates a slide 2, which is generally in the shape of a "U", with parallel arms 3 and 4, and a rear projection 5, and is housed in bosses of the cover 1, which are delimited by a projecting edge 6, which closes the bosses on the exterior. The slide 2 is faced by the sides of a main section, which position the arms 3 and 4 relative to the apertures 7 and 8, which correspond to the position of the contact pins, such that in the closing position shown in figure 1, the contact pins cannot be introduced, since this is prevented by the slide 2 which is opposite the apertures.

[0013] The displacement of the slide takes place by means of the arrangement of inclined planes, as indicated by number 9 in figure 2, in the areas which face the inlet apertures 7 and 8. By this means, the element of force on a plane which is parallel to the slide 2 gives rise to displacement of the latter until the apertures 7 and 8 are opened, thus permitting insertion of the contact pins.

[0014] In the embodiment according to the present invention, some flanges 10 and 11 in the interior of the cover 1 are designed to carry out accurate guiding of the respective inner sides 12 and 13 of the arms 3 and 4, when the slide 2 is advanced by the aforementioned mechanism, i.e. by the thrust of the contact pins. The dimensions of the arrangement of the flanges 10 and 11 relative to the inner faces 12 and 13 are such as to permit accurate adjustment with sliding movement, but with very little play between these components. In other words, in order for it to be possible for the arms 3 and 4 to be guided by their inner faces by the flanges 10 and 11, the displacement of the slide must take place in a manner which is straight and without lateral deflections. The rear projection 5 has a straight internal groove 50 which is parallel to the sides of said projection, said groove narrowing to form the groove 51 which has a smaller cross section, forming the hook-like steps 52 and 53. The cover has a rib 54 straight and coaxial with grooves 50 and 51 having in its end a V form indentation 55, which two sides are liable to abut respectively against stops 52 and 53 in case that a deviation of the slide should occur in its operation. It is precisely by acting on this principle according to the present invention, that off-centred actuation of the slide is prevented. In fact, the slide is mounted such that the rear projection 5 is guided by the inner faces 14 and 15 of both partitions of the interior of the cover 1, with a specific play or gap, such that slight rotation of the slide along its own axis is possible, i.e. along an axis which is perpendicular to the plane of the drawing, when actuation takes place with only one of the contact pins in only one of the apertures 7 or 8. In these conditions, the slide is pivoted slightly on its own axis, owing to the action of the spring, such that one or another of the quoins 16 and 17 of the inner faces 12 and 13 of the arms 3 and 4 strike against one or the other of the steps 18 and 19 which exist in the initial section of the flanges 10 and 11. In this situation, the slide 2 cannot advance. At the same time, one of the sides of the indentation 55 will colide against one or the other of the corresponding steps 52 and 53 as shown in Figure 16.

[0015] By means of this arrangement, the slide 2 can advance only when actuation takes place simultaneously by means of the two contact pins of a male socket in the apertures of the connection base 1, since otherwise the slide cannot be displaced and a component cannot be introduced individually in a single one of the contact alveoli, thus preventing this possibility of accidents.

[0016] As shown in figure 1 and in figure 1 bis, the end edges of the arms 3 and 4, which form the locking quoins or points 16 and 17, represented by the numbers 16' and 17', form a specific angle which opens towards the exterior, and is designed to be connected to the opposite edge of the corresponding steps 18 and 19, indicated by the numbers 18' and 19'. By means of this arrangement, when the slide reaches the stop, if eccentric force is applied to it, a force is produced whereby the corresponding arm is inclined to move towards the interior, thus tending to reinforce the stop action.

[0017] As already stated, in order to avoid the possible introduction of conductive components into the inlet apertures 7 and 8 of the socket base, when the slide 2 is in the safety stop position, in other words when it has been actuated eccentrically, the separation "x" in figure 2 bis between the rear edge of the slide and the edge of the inlet apertures 7 and 8 for the pins is designed to be greater than the path "y", figure 1 bis, to be travelled by the parts of the stop 16 and 17 of the slide on the corresponding reception area of the cover of the socket. By this means it is guaranteed that if the slide 2 is locked because eccentric force has been exerted on it, in the locking position the inlet apertures 7 and 8 for the pins continue to be closed, and do not permit introduction of conductive electrical components.

[0018] In order to maintain the slide in its closing position, i.e. in the rest position, according to the present invention integrated antagonistic springs are provided, for example the spring 26, which acts on internal L-shaped strips 20, which are provided with two arms 22 and 22', the former being supported in the interior of the body 23 of the socket base, which in the case in question can correspond to an adaptor device which supports external contact pins 24. As can be seen in figure 2, the spring 26 is slightly inclined and supported on a stamped part of the arm 22, by this means obtaining more efficient action. The end of the arm 22 is accommodated in the interior of a slot 25 of the slide 2. The contact by the contact pins to be introduced via the apertures 7 and 8 is obtained firstly by the arm 22 of the strip 20, and secondly by the parallel arm 27 of a second strip 28, the other arm 21 of which is adapted to the interior of the body 23. Both the strip 20 and the strip 28 are secured at the end 29 of the contact pin 24. When the male plugs are introduced via the apertures 7 and 8, each of the latter receives the double contact produced for example by the arms 22 and 27, which receive this contact pin between the two of them.

[0019] Figure 5 shows the springs, which are numbered 26 and 26', corresponding to the two contacts. The central spring 30 is designed for the earthing contact. In a variant embodiment shown in figures 11 and 12, the slide 31 is subjected to the action of helical springs 32, which are partially accommodated in apertures 33 of the arms, for example that which is indicated 34 in figure 11. This version corresponds to a socket base in which there are no internal strips, as shown in figure 2 and the successive figures. This corresponds to a version with flat pins 35, 36 and 37.

[0020] It will be appreciated that by means of the device described, it is possible to produce socket bases, adaptors and the like, in which electrical contact is established with an external component by means of a pin-type plug, in order to be able to obtain a maximum level of protection against the introduction of prohibited objects which can create unplanned contacts, with the consequent possibility of accidents.

Claims

1. Socket base with a safety device, of the type which has a flat slide, which can be displaced in the cover of the socket base, the slide having a rest position in which it closes the inlets for contact pins for connection to the socket base, and another position in which these apertures are opened by means of the axial action of the contact pins on the slide, characterised in that the slide has a "U"-shaped structure with two arms which are parallel to one another, which can be guided by two straight flanges of the socket base during movement from the rest position, whereas the slide itself is guided opposite to these arms, by a projection or by projections guided by surfaces in the body itself of the socket base, the movement between the arms of the slide and the guide areas of the latter being sliding movement, with the minimum play required in order to permit the displacement, whereas guiding of the projection(s) of the rear part of the slide by said guides takes place with considerable lateral play, thus permitting initial pivoting of the slide around an axis which is perpendicular to the slide, when eccentric force is applied to the slide, thus locking the latter and preventing it from being displaced.

2. Socket base with a safety device according to claim 1, characterized by a straigh groove on the rear projection of the slide, which has a narrower portion near the end, forming hook-like steps, a straight rib of the cover being located within the broader part of said groove which rib has in its end a V type indentation.

3. Socket base with a safety device according to claim 1, characterised in that the arms of the slide are guided by the inner edges of these arms, which act on two opposite flanges of the cover of the socket base, in the initial section of which there are steps which can make contact with one or the other of quoins of the arms of the slide, simultaneously with the abutment action of one of hook-like steps of the lengthwise groove of the rear projection of the slide with the corresponding side of the V indentation of the rib of the cover, which rib is located within said groove, thus preventing the slide from being displaced in a straight manner, if eccentric force is applied in the apertures for introduction of the plug pins causing the rotation of the slide.

4. Socket base with a safety device according to claim 2, characterised in that end edges of the arms of the slide have a small angle which opens towards the exterior, in order in the safety locking position to permit connection to the stop steps, which have corresponding angles, in order to permit better retention of the arm in its stop position, if eccentric force is applied to the slide.

5. Socket base with a safety device according to claim 1, characterised in that the rearward guiding of the slide is carried out by means of an extension on the two straight sides of the rear edge of the slide, which slides with a considerable amount of play, between two lateral guide surfaces of the socket base.

6. Socket base with a safety device according to claim 1, characterised in that an opposing or antagonistic action on the slide in order to lock the latter in the rest position, is provided by helical springs, which act directly on the slide.

7. Socket base with a safety device according to claim 5, characterised in that the helical springs are partially accommodated in recesses which are provided in the arms of the slide.

8. Socket base with a safety device according to claim 1, characterised in that the gap between a stop for the rear edge of the slide, and the edge of the apertures for intake of the contact pins, is greater than the path travelled between the end of the arms of the slide and its stops, if eccentric force is applied, thus blocking the passage of the apertures completely in the safety stop position of the slide.

Drawing