Adapter for the electrical connection between a towing vehicle and a trailer

Abstract: An adapter device for the electrical connection between a towing vehicle and a trailer, comprising a first type of connector which is electrically connected to two second type connectors. The body of the device consists of two parts (4, 5) which are fixed in an extractable way to delimit an engagement seat (4D, 12) for a connection element (6) fixedly inserted in a cavity (4B) of the first part (4). The engagement seat is delimited by a stop surface (4D) formed in said cavity (4B) and by supporting means (12), integrated with the second part (5) and projecting from the latter in the first part (4).

Description: The invention refers to an adapter for the electrical connection between a towing vehicle and a trailer of the type indicated in the preamble to claim 1. In order to interconnect two systems or electrical circuits, one pertaining to the towing vehicle and the other pertaining to a trailer, a plug and a socket connected to the towing vehicle and to the trailer, respectively, are commonly used. EP1 049 212 describes such an interconnection system. Said interconnection was firstly employed to permit controlling the electrical power circuit of the trailer lights (taillights, brake lights, reverse lights, direction indicators, etc.) by the towing vehicle. The later introduction of additional electrical and electronic systems aboard trailers (e.g. ABS brake control systems) has determined in recent times the progressive increase in the number of electrical connections required. Consequently, recently manufactured towing vehicles and trailers may have respective connectors equipped with a number of electrical contacts which is higher than in the past. In the case in which a towing vehicle equipped with a connector for powering and/or controlling a plurality of electrical circuits must be coupled with a more traditional trailer, the problem of interfacing the respective connectors correctly arises. For this purpose, adapter devices have been proposed. Such devices comprise a first connector with a certain number of contacts on one end, susceptible of being coupled with the connector carried by the towing vehicle, and two second connectors on the other end, each with a number of contacts different from that of the first connector, in which at least one of the second connectors is susceptible of being coupled with the connector carried by the towing vehicle and the contacts of the first connector and electrically connected with the contacts of the second connector(s). The occupied area of the body of the adapter devices of the known type is usually high, especially in length. This is to facilitate the assembly operations of the various components inside the body and the electrical connection, via conductors, between the contacts of the first connector and those of the second connector(s). Due to the large occupied area in length, the adapter devices on the known type are subjected to considerable mechanical stress during travel of the towing vehicle, such stress being susceptible of damaging the device itself. The object of this invention is to make an adapter device of the type shown with simple construction and assembly, contained size, reliable operation in time and high robustness. These objects and others, which will be better explained below, are achieved according to the invention by an adapter device having the characteristics specifically recited in the annexed claims. Additional objects, the characteristics and advantages of the invention will now be described, by the way of example only, with reference to the accompanying drawings wherein: figure 1 is a perspective view of an adapter device according to the principles of the invention, figure 2 is a partial schematic cross-sectional view according to the line II-II of figure 1, figure 3 is partial schematic cross-sectional view according to the line III-III in figure 1, figure 4 is an exploded view in enlarged scale of the adapter device in figure 1. In figure 1, numeral 1 generally indicates an adapter device made according to the principles of the invention, comprising a housing 2 for a multipolar connector of the first type on one end and two housings 3 for respective multipolar connectors of the second type on the other end. For the sake of simplicity in this description, we will suppose that the connector of housing 2 is a 15-pole plug intended to be coupled with a complementary socket carried by a generic towing vehicle, while the connectors of the housings 3 are 7-pole sockets, at least one of which is intended to be coupled with a complementary plug associated to a generic trailer. According to this invention, the device 1 consists of three main parts, clearly visible in figure 4, precisely a first body and a second body, indicated with numerals 4 and 5, intended to be reciprocally coupled, between which a contract holder 6 is arranged. The body 4 is made of a single piece of printed plastic material, which is shaped to define a flared portion 4A from which a tubular portion 4B departs and forms the aforesaid housing 2 of figure 1. As will clearly appear in the description that follows, the tubular portion 4B is intended to receive a substantial part of the contact carrier 6. Reference 4C indicates through holes in the flared portion 4A for receiving screws 7 for fastening the body 4 to the body 5. Numeral 8 generally indicates a fastening system of the type per se known. In the example shown, the fastening system 8 is a lever system with a pair of diametrically opposite pins 8A, associated to the body 4 on the sides of the tubular portion 4A; a generally arched element 8B presenting two arms 8C, each carrying a respective wheel 8C and a lever appendix 8D to operate the device 8, pivots between the pins 8A; according to prior art, the fastening system 8 is provided for ensuring both the electrical connection and the mechanical connection of the device 1, by engaging the wheels 8C with the respective projections on the body of the socket associated to the towing vehicle. Note that, instead of the fastener 8, the mechanical locking system between the device 1 and the connector of the towing vehicle may consist of a bayonet type coupling of the type known in prior art. A continuous seat is defined along the edge of the flared portion 4A, indicated with reference 5D in figures 2 and 3, intended to co-operate with a respective seal carried by the body 5. The internal cavity of the tubular portion 4B of the body 4 presents an initial widening, indicated with reference 4D in figure 2, the functions of which are explained below. As mentioned above, the body 5 defines a two housings on one side. As shown in figure 2, an internal seat 3A, whose shape is essentially cylindrical and whose bottom can also be seen in figure 4, corresponds to each housing 3 in figure 1; figure 4 shows that the body 5 defines a cavity 5A in which the rear part of the seats 3A are arranged. Each of the seats 3A is intended to house a respective set of electrical contacts of the known type, whose rear parts are indicated with reference 3B in figure 4. For this purpose, the seats 3A are made in one part with body 5, the latter being made of plastic material co-moulded by injection with the contacts 3B, so that the prevalent part of the contacts, intended to form the male terminal, projects inside the seats 3A, while the rear part of the contacts 3B remains within the cavity 5A of the body 5. It will be noted that the aforesaid terminals 3B, as the internal contact carrier terminals 6 and the respective electrical connection wires, are not illustrated in figure 2 and 3 for the sake of clarity. Again in figure 4, numeral 9 indicates isolated electrical wires, whose internal conductors are directly crimped on the part of the contacts 3A, which project inside the cavity 5A of the body 5. Numeral 11 indicates two covers or caps of plastic material each hinged in the known way in correspondence with a housing 3 of the body 5. The covers 11 are kept in a normally closed position of the seats 3A via respective springs, one of which is indicated with reference 11A in figure 4. A continuous ridge 5B is present along the edge of the body 5, intended to couple with the body 4, with the function of a seal and intended to be inserted in the corresponding seat 4D (figure 2) in the body 4; the mentioned ridge can be made of a suitable seal, of the type per se known, for example moulded over the body 5. Finally, the body 5 defines flange portions near the edge with the ridge 5B in which holes 5C are provided, in which the screws 7 are intended to engage. The contact carrier 6, which forms the connector of the housing 2 in figure 1, is configured as a separate and distinct part with respect to the bodies 4 and 5, whose prevalent section is intended to by inserted in an extractable way inside the tubular portion of the body 4. Essentially, the contact carrier 6 is of the known type and presents a main body made of moulded plastic material. This body presents a base, indicated with reference 6A, from which a portion 6B rises. A plurality of passages are formed in the portion 6B, each of which houses the prevalent part of the respective female terminals of the known type; the remaining part of such terminals, defining screw clamps, is accessible from the base 6A to allow connecting the terminals to the conductors 9; numeral 10 in figure 4 shows the screws of some of said screw clamps. In the assembled condition of the device 1, the contact carrier 6 is kept in a fixed angular position inside the tubular portion 4B of the body 4, with means which are per se known; in the illustrated example, these means consists of a longitudinal ridge, indicated with 4B' in figure 4, present on the internal surface of the tubular portion 4B and destined to engage a corresponding groove 6B' on the external surface of the upper portion 3B of the contact carrier 6; the ridge 4B' and the groove 6B' advantageously double as polarisation means, for permitting the insertion of the contact carrier 6 in the tubular portion 4A in a single possible way. According to the invention, the plastic material body 5 directly defines supporting means for the contact carrier 6. In the example shown, the supporting means consist of at least two riser elements, indicated with numeral 12, elevating from an intermediate position of the cavity 5A of the body 5 and projecting from the body 5 particularly in the space existing between the seats 3A. In the example shown, the two risers 12 are reciprocally counterpoised, each present a circular sector section and longitudinal stiffener ribbings, indicated with reference 12A, on the external surface. The assembly of the device 1 according to the invention is very simple. The respective covers 11, equipped with springs 11A, are hinged in a known way to the body 5, which is co-moulded with the respective contacts 3B onto which the various conductors 9 were previously crimped. The free ends of the electrical conductors of the wires 9 are then connected to the respective screw clamps in the contact carrier 6; this operation is easy, thanks to a certain length of the wires 9 and because the contact carrier 6 is configured as a separate part with respect to the bodies 4 and 5. Having made the necessary connections, the contact carrier 6 can be arranged on the upper ends of the two risers 12, being a precise zone delimited there for housing and guiding the wires 9. It will be noted that in a possible embodiment of the invention, reciprocal coupling means, for example consisting of seats in the base 6B for receiving an end portion of the risers, can be provided between the upper ends of the risers 12 and the contact carrier 6. The body 4 is then fitted on the body 5, so that the tubular end portion 4B of the first body is inserted in the contact carrier 6; the screws 7 are inserted between the holes 4C and 5C to be tightened. As can also be seen in figure 2, the initial widening 4D of the internal cavity of the tubular portion 4B of the body 4 makes a ledge for the base 6A of the contact carrier, to stop the insertion of the latter in the tubular portion 4B. After fastening the screws, which causes the progressive approach of the bodies 4 and 5, the contact carrier 6 is fastened in position by being directly interposed between the bodies 4 and 5, and, in particular, on one side by means of the risers 12 and on the other side by means of the ledge formed on the widening 4D; in this condition, the precise coupling between the sealing ridge 5B of the body 5 and the respective seat 4D in the body 4 is also obtained. In the case in which, for example, the electrical connections between the contacts 3B and the screw clamps of the connection elements 6 must be changed, the device 1 can be easily disassembled by reversing the operations described above. The characteristics of the invention as well as the advantages clearly results from description above. The arrangement of the contact carrier element 6 as a separate component, housed in the body 4 and supported by the risers 12 of the body 5, makes the device 1 very compact, especially by reducing the occupied area in length, facilitating the assembly/disassembly operations and the arrangement of the connection wires 9 at the same time.

Claims: Adapter device for the electrical connection between a towing vehicle and a trailer, the device (1) comprising a body (4, 5) with a first end and a second end, wherein: the first end defines a first housing (2) in which a first set of electrical contacts (10) is positioned, the set being intended to couple with the respective complementary electrical contacts belonging to the connector associated to either of said towing vehicle or trailer; the second end defines at least two second housings (3, 3A) in which a second set of electrical contacts (3B) is positioned, the set being intended to couple with the respective complementary electrical contacts belonging to the connector associated to either of said towing vehicle or trailer; electrical connection wires (9) are provided between said first contacts (10) and said second contacts (3A), characterised in that said body is formed by a first part (4) and a second part (5), reciprocally fastened in an extractable way to delimit an engagement seat (4D, 12) for at least a portion (6A) of a connection element (6) integrating said first contacts (10), said connection element (6) being configured as a separate and distinct component with respect to said parts (4, 5) and being removably inserted in a first cavity (4B) of said first part (4), where said engagement seat is longitudinally delimited, on one end, by a stop surface (4D) formed in said first cavity (4B) and, on the other end, by supporting means (12) integrated with said second part (5) and projecting from the latter from said first part (4), a space for housing at least a part of said wires (9) being provided between said supporting means (12) and said connection element (6). Device according to claim 1, characterised in that said supporting means comprise at least two risers (12) which elevate from a second cavity (5A) formed in said second part (5). Device according to claim 2, characterised in that said first cavity is formed by a tubular portion (4B) of said fist part (4) which forms said first housing (2) and in that each of said second housings (3, 3A) presents a bottom wall projecting from said second cavity (5A), each bottom wall being crossed by respective second contacts (3B). Device according to claim 2, characterised in that said risers (12) are reciprocally counterpoised (12), at least one of which has a circular sector shape and presents longitudinal stiffener ribbings (12A) on its surface. Device according to claim 2, characterised in that reciprocal coupling means are provided between the ends of said risers (12) and said connecting element (6).

Inventors: PASOTTO GIORGIO, PASOTTO, GIORGIO
Applicants: MENBER S SPA, MENBER'S S.P.A.
Application year: 2001
Main classification: H01R31
IPC codes: H01R31