Abstract:
The invention relates to a multi-pole multiple plug for connecting (small) electric appliances to a selection of different mains connection systems. The plug has internationally standardized pin arrangements ( 2 ) an the four sides of its housing ( 1 ) and an the base of the housing ( 1 ) is fitted with a recess for adjustably housing a contact tube ( 4-7 ) situated at the free end of a connecting cable ( 3 ) so that the strands of the connecting cable ( 4-7 ) can be connected inside the housing ( 1 ) With the pin arrangement ( 2 ) required at any particular time.

Description:
FIELD OF THE INVENTION 
     The invention relates to a multiple plug for a multipole, especially two-pole or three-pole, connection of electric devices, especially small devices such as computer and telecommunication equipment, electric shaving devices or hair driers, to internally different electrical outlet systems. 
     BACKGROUND OF THE INVENTION 
     For connecting electrical devices to the different electrical outlet systems found throughout the world, travel plug sets are known which consist of several adapter plugs, each of which is configured to adapt a given plug system to different outlet systems. In the face of this, it was attempted to make an intermediate plug that was alternatively usable for several different plug systems with the aid of slide mechanics and by the turning-out of individual plug pins (see, e.g., DE 297 01 285 U1). This device, however, is neither properly nor safely handled by a non-electrician, even with the aid of the operating instructions. 
     In view of this, there has come into practice the use of special plug adapters which allow electrical devices equipped with the plug configuration used in a given country to be used in the manner of a combined intermediate plug also in the plug outlets present in other countries and parts of the world. 
     Such a multiple plug adapter is described in DE 36 01 469 A1. This reference describes a connecting piece which, in the form of a penta-prism, has on its side surfaces the plug pin arrangements of different plugging systems and internally supports a rotary body which contains in the area of the cover and/or base surface of the connecting piece plug outlets for further plugging systems. This device can be manually adjusted with for the particular required plug pin arrangement of the plug body with the remaining plug pins standing free. 
     Because such adapters are a separate and independent component from the electrical device they always have the disadvantage of being easily misplaced or even of getting lost. In addition, there are the disadvantages of size and scope of such traveling adapters as well as their cost. 
     SUMMARY OF THE INVENTION 
     In view of this, underlying the present invention is the problem of designing a usable plug directly on the power cord of an electrical device so that the electrical device can be plugged at will into the outlets of several differently configured electrical outlet systems without the need for additional intermediate connecting elements. 
     The problem is solved according to the present invention by a multiple plug comprising a block shaped housing having a first side surface from which extends various standardized plug pin arrangements for different plug systems and a second side surface which has a recess into which a contact carrier is adjustably supported. The contact carrier is firmly secured to the free end of the connecting cable. The contacts of the contact carrier are connected with the electrical strands of the connecting cable. The plug pins associated with the different plug systems are selectively connectable with the contacts of the contact carrier via mating counter contacts provided on the plug pins. By moving the housing relative to the contact carrier, the plug pins of one of the given standardized pin arrangements can be brought into conducting engagement with the contacts of the contact carrier to thereby allow the electrical device to be used in that type of plug and outlet electrical connection system. Thus, the electrical device can be adjusted for use in different plug and outlet systems simply by aligning the contacts on the contact sleeve with the desired standardized plug pin arrangement. 
    
    
     These and other features and advantages of the present invention will be more readily apparent upon reading the following description of exemplary embodiments of the invention and upon reference to the accompanying drawings wherein: 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view of an illustrative multiple plug according to the present invention having different standardized pin arrangements, 
     FIG. 2 is another side view of the multiple plug of FIG. 1, 
     FIG. 3 is a bottom view of the base surface of the multiple plug of FIG. 1, 
     FIG. 4 is a side view of a contact sleeve of the multiple plug of FIG. 1, 
     FIG. 5 is a partially sectioned side view of the multiple plug of FIG. 1, 
     FIG. 6 is a partially sectioned plan view of the base surface of the multiple plug of FIG. 1, 
     FIG. 7 is a schematic drawing of a plug pin arrangement according to the Australian standard, 
     FIGS. 8 and 9 are side views of a multiple plug similar to that of FIG. 1 which has been modified to accommodate a pin arrangement according to the Australian standard, 
     FIG. 10 is a plan view of the upper surface of the housing of the multiple plug of FIGS. 8 and 9, 
     FIGS. 11-13 are enlarged partial side views of the multiple plug of FIGS. 8 and 9 showing the releasing contact moving between a rest position and an operating position, 
     FIGS. 14 and 15 are side view of an another embodiment of a multiple plug according to the present invention having a three-pole configuration, 
     FIG. 16 is a plan view of the base surface of the multiple plug according to FIGS. 14 and 15, 
     FIG. 17 is a side view of the contact sleeve of the multiple plug according to FIGS. 14 and 15 which includes an optical display device, 
     FIG. 18 is a partially sectioned side view of the multiple plug of FIGS. 14 and 15, 
     FIG. 19 is a partially sectioned side view of the base surface of the multiple plug of FIGS. 14 and 15, 
     FIG. 20 is a partially sectioned side view of a further embodiment of a contact sleeve, 
     FIG. 21 is a sectioned side view of another embodiment of a multiple plug according to the invention, 
     FIG. 22 is a plan view of a further embedment of a contact sleeve, 
     FIG. 23 is a front plan view of a group of pin arrangement having a slidable plug pin, 
     FIG. 24 is a perspective view of an adapter for modifying a configuration of the multiple plug according to the British standard for the configuration according to the German/Austrian standard and the French/Belgian standard, 
     FIG. 25 is a perspective view of the adapter of FIG. 24 as installed on a multiple plug according to the present invention, and 
     FIG. 26 is another perspective view of the adapter of FIG. 24 as installed on a multiple plug according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As is evident from the drawings, the plug housing  1  of insulating material has on its side surface the plug pin arrangements of four different internationally standardized electrical connecting systems. In the interest of clarity, only the pins of the European configured plug, to the left in FIGS. 1,  3 ,  5  and  6 , are provided with the reference number  2 . For adjustably supporting the connecting cable  3  in the plug housing  1 , a contact sleeve  4  is provided on the cable end which is separately shown in FIG.  4 . The contact sleeve  4  is, in turn, supported in a recess in the plug housing in such a manner that the position of the contact sleeve  4  can be adjusted relative to the plug housing  1 . 
     The contact sleeve  4  consists of a plastic hollow cylinder into which the connecting cable  3  is inserted. The electrical strands of the connecting cable are connected with contact paths  5  (see FIGS.  4  and  5 ), which are present on the outer circumference of the hollow cylinder of the contact sleeve  4 . The connecting cable  3  is acted upon in its sheath by a plurality of barbs  9  (FIG. 5) that are arranged in the contact sleeve and surround the connecting cable and extend in the insertion direction. In the event of a tension stress on the connecting cable  3 , the barbs  9  can penetrate into the sheathing by means of their acutely converging ends and thus prevent the cable from pulling out of the contact sleeve  4 . 
     Further, the contact sleeve  4  is provided in the axial direction, after the contact paths  5  and before a knurled flange  6 , with an annular groove  7  that facilitates adjustment of the position of the contact sleeve relative to the housing. A guide lip which extends from the side of the recess opening in the plug housing I extends into the annular groove  7  when the contact sleeve is assembled into the plug housing as shown in FIG.  5 . It is possible to install a conventional locking mechanism or device between the plug housing  1  and the knurled flange  6  which would facilitate precise manual adjustment of the contact sleeve  4  into, in this case, the four use positions that are offset to one another by 90°. 
     The adjustability of the contact sleeve  4  relative to the plug housing  1  allows the two contact paths  5  on the contact sleeve to be selectively brought into engagement with mating contact sets  8  which extend from the connecting ends of the different plug pins. The mating contact sets (FIGS. 5 and 6) are resilient and extend in the correct pole orientation from the connecting ends of the different plug pins  2  into the recess of the plug housing where the contact sleeve  4  is adjustably supported. 
     In this manner, before use, it is possible to adjust the proposed multiple plug simply by hand by first rotating the guiding cable in the direction of the required plugging system and securing the respective plugging pins for that system into the plugging outlet. After this, the required change of the electrical device to that plugging system can be brought about just as simply and safely by merely turning the knurled flange  6  on the contact sleeve  4  so as to move the contact paths  5  on the sleeve  4  into conductive engagement with the mating contact set  8  associated with the plugging pins of the appropriate plugging system. 
     For establishing a connection with a plug outlet according to the Australian standard there is taken into account the peculiarity that the plug pin arrangement provided for Australia—besides the two flank contact pins according to FIGS. 2 and 3 of the drawing, projecting obliquely to one another, and as shown separately in FIG.  7 —also includes a somewhat longer releasing (flat) pin. This releasing pin first mechanically frees the two pole contact bushes in the interior of the Australian plug outlet during the insertion process before an electrical connection is established. 
     In order to supplement the multiple plug of the present invention for this type of plug arrangement, it can be provided, as shown in FIGS. 8 to  10 , with a flat pin  10  that is pivotable about an axis of rotation fixed to the plug housing. The flat pin  10  is arranged on the surface of the housing opposing the end of the housing in which the cable is introduced. The pivotal connection of the flat pin  10  to the housing  1  is arranged near the front side of the plug housing  1 , within an oblong hole guide on the rearward end of the fiat pin  10 . This arrangement allows the flat pin  10  to pivot between a rest position wherein the flat pin is arranged in a slot-form housing pocket  11  extending rearward to the outside through 180° into a contact position proper wherein the flat pin  10  is arranged above the two obliquely standing pole contact pins  2 ′, as is represented successively in FIGS. 11 to  13 . In the rest position, an onset cam  12  projects from the housing surface serving as handle. The cam  12  also serves to lock the flat pin relative to the housing when the flat pin is in the contact position. Specifically, the cam  12  is received in a front recess of the housing pocket  11  and in this manner fixes the flat pin  10  securely onto the plug housing  1 . The flat pin  10  is made as a stamped part with an open guide shank as shown in FIG.  11  and can be later fitted onto the pivot pin provided on the housing. 
     In FIGS. 14 to  19 , a first embodiment of a three-pole protective contact multiple plug according to the present invention is shown. As is evident from FIGS. 14 and 15, the protective contact multiple plug carries on its side surfaces the plug pin arrangements of four different connecting systems, namely according to, with reference to FIGS. 16 and 19, the German standard system, on the left the Swiss standard system, above the Italian standard system, and on the right side the British standard system. In the interest of clarity in each case only the protective contact pins of the foreign plugs or the laterally lowered metal inlays on the German plug which contact the springy slide contacts on the sides of a protective German contact outlet, are provided with the reference number  2 ′. Moreover, for adjustably supporting the connecting cable  3 ′ in the housing  1 ′ of the multiple plug, a contact sleeve  4 ′, separately shown in FIG. 17, is provided on the appropriate end of the connecting cable. 
     The contact sleeve  4 ′ carries on its cylindrical outer surface the contact paths  5 ′ which are connected with the line strands of the connecting cable  3 ′. In this case, the contact paths  5 ′ are applied in two successive rows on the contact sleeve. 
     In a similar arrangement to the FIG. 1 embodiment, when the contact sleeve is inserted inside the recess in the base surface of the housing  1 ′, the contact paths  5 ′ can be brought into conductive contact with the corresponding mating contacts  8 ′ on the connection end of the corresponding plug pins  2 ′, or respectively on the corresponding metal inlays (protective contacts) according to the German standard, by manually adjusting the position of the contact sleeve relative to the housing. In this case, the mating contacts  8 ′, which extend under spring tension from the ends of the plug pins or of the metal inlays in the direction of the inserted contact sleeve  4 ′, are spaced in a corresponding manner to the spacing of the contact coatings  5 ′ on the contact sleeve. 
     Similar again to the embodiment of FIG. 1, the contact sleeve includes a knurled flange  6 ′ which can be used to manually adjust the position of the contact sleeve relative to the plug housing by hand in order to set the multiple plug to the plug pin arrangement required for a particular plug and outlet system. 
     In order to give the user an indication as to whether the chosen local plug outlet is capable of functioning at all, an optical display device  13  is provided as shown in FIG. 17, which is connected over feed lines  14 ,  15  with the corresponding contact coatings  5 ′. In the illustrated embodiment, the display device comprises a glow lamp  16  which is connected in series with a protective resistor  17  on the contact coatings  5 ′. When the multiple plug is capable of functioning in a given outlet, the light generated by the display device  13  in the case of function-capable plug outlet can be seen the from outside either through a colored viewing window or through a fully transparent plug housing. It is also possible to make the contact sleeve itself, at least partially, out of a transparent material and to arrange the display device  13  inside the contact sleeve. If necessary, the surface of the plug housing opposite the base surface where the connection cable is received can have a viewing window and/or, at least partially, consist of a transparent material. In any case, the operator immediately via the lighting-up of the display  13  that the contact sleeve  4 ′ was turned into the correct position and that the plug outlet uses the desired voltage, so that an electric apparatus can be put into operation. 
     For the rotatable support of the contact sleeve  4 ′, the housing engages by means of a guide lip into an annular groove  7  provided between the sleeve body and the knurled flange  6 ′. In the area of the knurled flange, a retaining mechanism  9 ′ for the connecting cable  3 ′ and a locking mechanism (not shown), with which the contact sleeve  4 ′ can be set exactly on the desired plug pin arrangement are provided. 
     FIG. 20 is a partially sectioned side view of a further embodiment a contact sleeve  18 . In order to achieve a simple and low-friction support of the contact sleeve  18  within the multiple plug,  1 ,  1 ′, locking elements  20  are provided in a outer wall  19  of the contact sleeve  18 . These are an integral component of the contact sleeve  18  and are pivotable about a joint  21 . The locking element  20  has a lug  22  which bears on an underside of the guide web bounding the opening to the recess in the plug housing  1 ,  1 ′. Thereby, an easy turning of the contact sleeve  18  is made possible, in which process simultaneously a pulling-out of the contact sleeve  18  from the housing is precluded. 
     In order to ensure effective strain relief, a radial bore for the reception of a screw which exerts a force on the retaining mechanism  9 ′ is provided in the knurled flange  6 ′. 
     FIG. 21 illustrates a second embodiment of a three-pole protective contact multiple plug  24 , in which like elements are designated the same reference numbers used with the earlier described embodiments. The multiple plug  24  includes a plug pin arrangement  25  having at least one slidable protective contact pin  2 ′, which allows the plug pin arrangement  25  to be used in both connecting systems according to the Italian standard and connecting systems according to the Swiss standard. 
     Further, the multiple plug  24  is detachably connected with an adapter  26 . The adapter  26  is preferably arranged on a side surface of the multiple plug  24 , which has a plug pin arrangement according to the British standard. The British standard arrangment is distinguished by a projecting protective contact bow  27 , which together with main contacts (not shown) forms essentially an equilateral triangle. The protective contact bow  27  is completely received by a receptacle  28  inside the adapter  26 . An outside-lying surface area of the contact bow  27  is accessible through a recess  31  within the wall  32  of the adapter  26  as a first protective contact  30  according to the German/Austrian standard. 
     A second protective contact  33  is provided lying diagonally opposite the first protective contact  30 , which is likewise accessible over a recess  34  within the outer wall  32  of the adapter  26 . The second protective contact  33  is part of a sliding contact  35  which bears under spring tension preferably on an underside  36  of the protective contact bow  27 . For adapting to further configurations, especially according to the French/Belgian standard, a further receptacle  37  is provided which extends parallel or substantially parallel to, and underneath, the protective bow  27 . This serves for the reception of a plug outlet side protective contact pin which is received by the receptacle  37  and is conductively connected with the underside  36  of the contact bow when the multiple plug is plugged in. In addition, the plug outlet side protective contact pin is pressed over a bow-shaped section  38  of the slide contact  35  against the underside  36  of the protective contact bow  27  in order to establish an electrically conducting contact. 
     This arrangement utilizes the fact that the arrangement of the main contacts  39  according to the German/Austrian standard and the French/Belgian standard essentially coincide. The outer configuration of the adapter  26  essentially resembles the shape of a standardized protective contact plug. 
     For fastening the adapter  26  to the multiple plug  24 , the multiple plug has a locking element  40  which is lockably anchored in a recess  41  in the outer housing zone of the multiple plug  24 . In the illustrated embodiment, a lug of the locking element  40  engages a projecting edge  42  of the essentially L-shaped protective contact bow  27 , so that the latter assumes a double function. The springy, bow-shaped section  35 ,  38  is firmly joined with the adapter  26 . 
     In this embodiment, the contact sleeve  43  has essentially the same structure as the previously-described contact sleeves  4 ,  4 ′. However, in contrast to the previously described embodiments, the contact sleeve  43  has a spring loaded protective conductor contact  44  and the mating contacts  45 ,  46  of the protective contact pins  27 ,  2 ′ are rigidly constructed. The protective conductor contact  44  is firmly joined, preferably over a soldered connection, with the protective conductor  47  of the connecting cable  3 . 
     FIG. 22 provides a plan view of the contact sleeve  43 . As shown, the protective conductor contact  44  is constructed as a contact pin, with a contact surface  48  which projects through an opening  49  in a wall  50  of the contact sleeve  43  and can be brought into conductive connection with the counter contacts  45 ,  46 . In order to produce the necessary contact pressure, a spiral spring  52  is arranged coaxially to a section  51  of the contact pin  44 . The spiral spring  52  extends between an inner wall  53  of the sleeve  43  and a soldering connection vane  54  of the protective conductor contact  44 . An element  55  lying opposite the contact surface  48  is supported in a further opening  56  of the wall  50  of the contact sleeve  43 . 
     As already mentioned above, the multiple plug  24  has a pin arrangement  25  which is changeable by sliding a plug pin out of a configuration according to the Italian standard, into a configuration according to the Swiss standard. Specifically, the protective contact  2 ′ is slidable out of a first position  57 , which preferably corresponds to a plug configuration according to the Italian standard, into a second position  58 , which preferably corresponds to a plug configuration according to Swiss standard as shown in FIG.  21 . 
     The protective contact  2 ′ is slidable counter to the force of a spring element  56 , in order to make possible a shifting out of the first position  57  into the second position  58 . 
     On the interior side of the plug the protective contact  2 ′ is conductively connected, by means of an anchor-shaped end  59 , with a contact bar  60 , which both forms the counter contact  46  and comprises a guide  61  for the anchor-shaped end zone  59 . The contact bar  60  is firmly joined with the housing of the multiple plug  24 , so that thereby also the protective contact  2 ′ is arrestable. The protective contact  2 ′ has a substantially cylindrical construction and has a tapering  62  in its end zone  59  which is slidable lengthwise in the guide  61 . As represented in FIG. 23, the guide  61  is constructed as an oblong hole  62 , with blind hole-type receptacles arranged in the end portions of the oblong hole  62 . The stamp-form end zone  59  of the protective contact  2 ′ is receivable in these receptacles. In particular, the receptacle  63  is allocated to the position  57  and the receptacle  64  to the position  58 . The spring element  56  ensures that the protective contact  2 ′ is held in the particular position  57 ,  58  and that there is established a sufficient electrical contact with the contact bar  60 . 
     As is further evident from FIG. 23, main contacts  65 ,  66  are arranged in a first plane and the protective contact  2 ′ is slidable in a second plane which runs perpendicular to the plane defined by the main contacts  65 ,  66 . In the position  57 , the protective contact  2 ′ is located in the plane defined by the main contacts  65 ,  66  and in the position  58  the protective contact  2 ′ defines a triangle with the main contacts  65 ,  66 . 
     FIG. 24 provides a three-dimensional representation of the adapter  26 . On the plug outlet side, the adapter essentially has the form of a commercially usual protective contact plug, as prescribed according to the German/Austrian standard. On the multiple plug side, the receptacles  28  and  37  are formed, which are designed with the first receptacle for the reception of the protective contact bow  27  according to the British standard and with the second receptacle  37  for the reception of the plug outlet side protective contact pin according to the French/Belgian standard. 
     Further receptacles  67 ,  68  are provided, into which the main plug pins mounted on the multiple plug  24  are introduced, in order to established a conductive connection with the main contacts  39  of the adapter. 
     Starting from the essentially cylindrical wall  32  there extends at least in areas, a wall zone  69  which has the same lengthwise dimension as the locking element  40 . The locking element  40  is preferably constructed parallel or essentially parallel to the upper surface  30  of the protective contact bow  27  and locks with this. 
     FIG. 25 provides a perspective depiction of the multiple plug  24  with adapter  26  in the assembled state. The locking element  40  is easily accessible over the recess  41  and can be released without the aid of a tool. 
     FIG. 26 provides a plan view of the multiple plug  24  with adapter  26  in perspective, which shows in particular the plug configuration  25  with slidable protective contact  2 ′. 
     In summary, the present invention provides a multiple plug which allows the connection of electrical devices to internationally differing connection systems. The multiple plug is firmly connected with the connecting line of the electrical with via a contact carrier rotatably supported inside a housing of the multiple plug. Thereby, the multiple plug cannot be removed and is a constant companion of the electric device. Through the contact carriers  4 ,  4 ′,  43 , the electric device can be conductively joined as desired with the various plug pins  2 ,  2 ′ arrangements provided on the multiple plug. 
     According to a further aspect of the invention, a slidable contact, particularly a protective contact  2 ′, can be provided which allows a plug pin arrangement to be fitted both to the Swiss and also to the Italian standard. 
     A further object of the invention with inventive character is an adapter  26  which can be connected with the multiple plug. The adapter makes the multiple plug of the present invention useable with two more standardized plugging systems. In the illustrated embodiment, the multiple plug  1 ,  1 ′,  24  has four different pin arrangements, which by reason of the slidable protective contact and the adapter  26  can provide seven different international standardized plug pin arrangements.