Electrical plug connection between a power source and an electrical work apparatus

An electrical plug connection is for electrically connecting a power source in a releasable manner to an electrical work apparatus. The plug connection includes at least one first electrical line for the purpose of transmitting electrical power and at least one second electrical line for the purpose of transmitting signals. The plug connection includes a plug with a plug body and one or more first plug contacts and a plug socket with first contact sockets, wherein the plug contacts of the first electrical line are arranged within the plug body. The plug contact of the second electrical line is in the form of an external contact in the region of an outer contour of the plug body, wherein a mating contact of the plug socket is associated with the external contact of the plug body. The external contact and the mating contact form a latching connection.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority of German patent application no. 10 2017 000 996.1, filed Jan. 30, 2017, the entire content of which is incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to an electrical plug connection for electrically connecting a power source, preferably a rechargeable battery pack, in a releasable manner to an electrical work apparatus, wherein the plug connection includes at least one first electrical line for the purpose of transmitting an electrical power and at least one second electrical line for the purpose of transmitting signals. The plug connection has a plug with a plug body and one or more first plug contacts and also a plug socket with first contact sockets, wherein the plug contacts of the first electrical line are arranged within the plug body.

BACKGROUND OF THE INVENTION

Signal lines which are to be provided separately from the electrical lines which transmit power are required for the purpose of communication between the electronics system of a rechargeable battery pack and the motor controller of an electrical work apparatus. Since the electrical lines have to transmit high currents for power transmission, corresponding line cross sections are provided. The number of electrical lines to be connected via a plug connection leads to a considerable physical size. When working with electrical work apparatuses, large, bulky plug connections are usually detrimental and hinder the work.

SUMMARY OF THE INVENTION

It is an object of the invention to provide an electrical plug connection for connecting a rechargeable battery pack to an electrical work apparatus, which is of small construction, can transmit a high electrical power and is mechanically reliably secured in a simple manner.

The object can, for example, be achieved via an electrical plug connection for releasable electrical connection of a power source to an electric work apparatus. The electrical plug connection includes: a first electrical line configured to transmit electrical power; at least one second electrical line configured to transmit signals; a plug including a plug body having an outer contour; a first plug contact; a plug socket having a first contact socket; the first plug contact being associated with the first electrical line and being arranged within the plug body; the second electrical line having a second plug contact; the second plug contact being configured as an external contact in the region of the outer contour; said plug socket having a mating contact associated with the external contact of the plug body; and, the mating contact and the external contact being configured to form a latching connection.

The plug contact between the second electrical line is in the form of an external contact in the region of an external contour of the plug body. As a result, the electrical contacts which are required for signal transmission can be shifted outward from the center of the plug connection, as a result of which the diameter of the plug connection can be kept small. A mating contact on the plug socket is associated with the external contact of the plug body, wherein the configuration is such that the external contact and the mating contact form a mechanical latching connection. Therefore, insertion of the plug into the plug socket of the electrical plug connection according to an aspect of the invention results not only in secure electrical contact-connection with prespecified operator control forces, but mechanical locking of the plug in the plug socket at the same time.

The external contact is arranged on the outer circumference of the plug body in a simple manner for the purpose of transmitting signals, with the result that the interior of the plug body can be used exclusively for the plug contacts for the electrical power transmission.

The mating contact on the plug socket is advantageously in the form of a spring tongue, as a result of which not only is a secure electrical contact-connection between the external contact and the mating contact ensured but, furthermore, mechanical latching is achieved in a simple manner. To this end, it may be advantageous when the external contact has a latching recess, a latching lug on the mating contact being associated with the latching recess. The latching lug is preferably formed by the free end of the mating contact.

In order to ensure simple insertion of the plug into the plug socket, it is provided to form a ramp in front of the external contact in the insertion direction of the plug body. When the plug is inserted, the latching lug of the mating contact slides on the ramp of the plug body, as a result of which the user receives haptic feedback in respect of the extent to which the plug is inserted on account of the increase in the plugging force which has to be applied. The user can easily establish whether the plug is inserted completely into the plug socket. This feedback is provided to the user by a maximum insertion force being exceeded and/or by a negative force (tensile force) which is generated owing to the configuration of the ramp.

The plug body of the plug advantageously has a plug end, which faces the plug socket, and a connection end which is held in a plug housing. A separating plane is expediently formed between the connection end and the plug housing, wherein the connection end and/or the plug housing have coupling fingers which pass through the separating plane. If, in a particular embodiment of the invention, the interior of the plug body and the interior of the plug housing are filled with an injection-molding compound, a mechanical connection is established between the plug body and the plug housing via the injection-molding compound. Since the coupling fingers protrude into the respective other part via the separating plane, a more secure mechanical connection is achieved between the plug body and the plug housing, the mechanical connection also being able to withstand high pull-out forces.

In a particular embodiment, the plug socket has a circumferential wall which delimits a receptacle for the plug body. The mating contact is situated radially outside the receptacle and protrudes, by way of a free contact end, through a receiving slot in the circumferential wall into the receptacle. The physical size of the plug connection can be kept small owing to the mating contacts being shifted radially outward.

The contact end advantageously has a stop tongue which delimits a protrusion of the contact end, which protrusion protrudes into the receiving space. In this way, the protrusion of the mating contact, which protrusion protrudes into the receiving space, is structurally defined.

In an end view of the plug body, the plug contacts of the first lines which transmit electrical power are situated with an offset in relation to one another. Accordingly, the contact sockets are situated with an offset in relation to one another in an end view of the plug socket. Owing to this offset arrangement of the plug contacts and, respectively, of the contact sockets, space is created in the connection region, this space providing a variety of possible ways of connecting the electrical lines to the plug and, respectively, to the plug socket.

The plug contacts are advantageously in the form of contact tongues which interact with contact sockets which are in the form of contact terminals.

In an advantageous embodiment of the invention, the mating contact of the plug socket has a contact region for making electrical contact with the external contact. An opening is advantageously formed in the contact region of the mating contact, as a result of which the electrical contact-connection can be improved.

The contact region advantageously has a highest elevation. The opening determines, by way of its opening edge, an opening area which is advantageously situated at a vertical distance below the highest elevation. When the highest elevation bears against a bearing surface, the opening area of the opening is situated at a distance from the bearing surface. It is advantageously provided that the opening width of the opening is wider than the width of the external contact. When contact is made, the external contact is situated within the opening area in plan view of the opening. The highest elevations of the contact surface, which highest elevations still exist next to the opening, are situated next to the external contact. There is an overlap between the mating contact and the external contact in side view of the external contact.

The external contact has a main body with two longitudinal edges. Since the width of the external contact, which width is measured between the longitudinal edges, is smaller than the opening width of the opening, the longitudinal edges come to bear against an opening edge of the opening at at least one bearing point so as to make electrical contact. In an advantageous embodiment, a bearing point which is at the front in the insertion direction and a bearing point which is at the rear in the insertion direction are provided on each longitudinal edge. Therefore, a total of four active bearing points can be produced, as a result of which good electrical contact-connection with interference-free signal transmission is ensured. When the mating contact slides onto the external contact, dirt and other interference particles are reliably removed, this promoting reliable electrical contact-connection.

The geometric configuration of the opening is provided in such a way that an edge section of the opening edge of the opening bears against the external contact so as to make electrical contact. An edge section of the opening edge which is at the front in the insertion direction and an edge section of the opening edge which is at the rear in the insertion direction preferably bear against the external contact. In this way, two edge sections can be used for reliable electrical contact-connection with interference-free signal transmission.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

FIGS. 1 to 3illustrate a plug connection1which, in the embodiment shown, is provided for electrically connecting a connection line16in a releasable manner to a power source, for example a rechargeable battery pack2. The connection line16connects the rechargeable battery pack2to an electrical work apparatus3, wherein a plug connection identical to that between the connection line16and the rechargeable battery pack2can be provided between the connection line16and the work apparatus3. The plug connection1is independent of the application between a rechargeable battery pack2and a work apparatus3which are specified by way of example, and can also be provided for connecting other electrical connections in a releasable manner. Therefore, it is generally possible to establish any desired connection between a power source and a load using the plug connection according to the invention. The plug connection can also be used for connecting an extension line to an existing connection line16.

Aspects of the invention are explained below using the example of the plug connection1between the connection line16and the rechargeable battery pack2.

The plug connection1includes a plug4and a plug socket8. The plug4has a plug body5and at least one plug contact6,7. Two plug contacts6and7are provided in the embodiment shown according toFIG. 3.

The plug socket8, in which at least one contact socket9,10for the plug contact6,7of the plug body5is provided, is associated with the plug4. Two contact sockets9and10are provided in the embodiment shown according toFIG. 3.

The plug body5further has at least one external contact11,12in the region of its outer contour. Two external contacts11,12which are arranged such that they are situated, in particular, diametrically opposite one another—with respect to a longitudinal center axis68of the plug4—are provided in the embodiment according toFIG. 3. The relative position of the external contacts11,12in relation to one another is mentioned by way of example; other positions may also be expedient. The number of external contacts can also be freely selected, for example three or more external contacts can also be provided. In the plug socket8, a mating contact13,14is in each case associated with an external contact11and, respectively,12. In this case, an external contact11,12and the associated mating contact13,14preferably form a latching connection15which is illustrated on an enlarged scale inFIGS. 18 and 19.

The connection line16is preferably a flexible line, in particular a plastic-sheathed or rubber-sheathed line. In the embodiment shown, the connection line16has first electrical lines17,18for the purpose of transmitting an electrical power. Furthermore, two electrical lines19,20which are used for the purpose of transmitting signals are provided. The first electrical lines17,18are connected to first connection lines97,98of the plug socket8via the plug connection1for the purpose of transmitting electrical power, whereas the second electrical lines19,20are connected to second connection lines99,100of the plug socket8via the plug connection1for the purpose of transmitting signals. Contact is made with the first connection lines97,98and the second connection lines99,100at the plug socket8.

The configuration of the plug4is shown inFIGS. 4 to 10. The plug substantially includes the plug body5, a plug housing21which is connected to the plug body5, and an end sleeve22.

The plug housing21is situated—as shown inFIG. 6—between the end sleeve22and the plug body5. The electrical connection line16has two first lines17,18for the purpose of transmitting power and two second lines19,20for signal transmission operations. The second lines19,20for the signal transmission operations are connected to the external contacts11,12; the first lines17,18are connected to the plug contacts6,7.

The plug housing21has an end side23which faces the plug body and defines a separating plane24(FIG. 8) between the plug body5and the plug housing21. The separating plane24is formed between a connection end25of the plug body5and the end side23of the plug housing21. As shown inFIGS. 7 and 8in particular, the plug housing21has coupling fingers26,27,28which pass through the separating plane24. The coupling fingers26,27,28project beyond the separating plane24by way of a partial length e. It may be expedient for the connection end25of the plug body5to have, as an alternative or in addition, coupling fingers which pass through the separating plane24. In the fitted position according toFIG. 9, the coupling fingers26protrude into the plug body5. The hollow space29in the plug body5and the hollow space30in the plug housing21are filled with an injection-molding compound31, in particular filled with an adhesive injection-molding compound31, preferably after the plug body5has been fitted to the plug housing21. To this end, an injection opening90(FIG. 8) can be provided in the plug housing21. The plug body5is fixedly connected by way of its connection end25to the plug housing21. The protruding end of the connection line16is also tightly connected to the plug4by the injection-molding compound31.

The plug housing21has an insertion end32for the connection line16. The connection line16is provided with a protective tube33for the purpose of forming a kink-prevention means. The connection line16runs through the protective tube33which is provided, in particular, as an articulated metal tube in the embodiment shown. That end34of the protective tube33which faces the plug housing21can be widened before fitting and the outside diameter A of the end can be expanded. In this way, the end34obtains an outside diameter A which is larger than an inside diameter I of an end sleeve22. The protective tube33is held in an axially interlocking manner on the plug housing21via the end sleeve22which is fixed on the insertion end32.

The end34of the protective tube33can also be widened in a different way. For example, a stopper—which is preferably provided in the end sleeve22—can be pushed into the end34of the protective tube33in order to widen the outside diameter A of the end34and in this way fix the end in the end sleeve22in an axially interlocking manner—advantageously when fitting the end sleeve22.

The end sleeve22is pushed axially over the insertion end32, wherein a latching ring35which is in the form of a spring ring and latches the end sleeve22onto the insertion end32of the plug housing21in an interlocking manner acts between the insertion end32of the plug housing21and the receiving section36. To this end, an external groove37is provided in the outer circumference of the insertion end32and an internal groove38is provided in the end sleeve22.

As shown in the end view of the plug end39of the plug body5, each plug contact6,7is situated in an associated contact area46,47. The contact areas46,47are separated from one another by a continuous separating wall40. In the embodiment shown, the plug contacts6,7, which are in the form of flat contacts, are situated in planes which are parallel to one another; however, the plug contacts6,7are displaced relative to one another by an offset v, as shown inFIG. 5. If more than two plug contacts are provided, different relative positions of the plug contacts in relation to one another may be expedient. If, for example, three plug contacts are provided, the plug contacts can lie in planes which in each case form an angle of, in particular, 120° in relation to one another.

The configuration of the plug socket8is shown inFIGS. 11 to 13.

The plug socket8has a receiving space42in which the plug body5is received. The plug contacts6,7engage in contact sockets9,10which are in the form of contact terminals43for receiving the plug contacts6,7which are in the form of contact tongues41.

Two receiving grooves44,45for positioning ribs48,49(FIGS. 4, 6), which are provided on the plug body, are situated in an offset manner over the circumference of the plug socket8. In the embodiment, the positioning ribs48,49have a different width in the circumferential direction in accordance with the intended receiving grooves44and45. The receiving grooves44,45and the positioning ribs48,49ensure insertion of the plug4in the insertion direction50into the plug socket8in the correct position.

Owing to the offset v of the contact sockets9,10and, respectively, of the plug contacts6,7, enough space is created on the connection side51, for example of the plug socket8, in order to be able to use different connection techniques for connecting the electrical lines17,18,19,20. For example,FIG. 13shows that the connection lines can be electrically connected on the connection side51(FIGS. 12, 13) of the contact socket9via screw contacts, solder contacts, crimp contacts, plug contacts or the like.

The contact sockets9,10are situated in the base of the plug socket8. The electrical lines17,18are connected to the contact sockets9,10and transmit the electrical power which is required for the purpose of operating the work apparatus3.

Signal transmission between the work apparatus3and the rechargeable battery pack2is performed via the second lines19,20which are in the form of signal lines. The signal lines are connected to mating contacts13,14. A mating contact13,14of this kind is in the form of a spring tongue52and is fixed at an end73on the connection side51of the plug socket8to the base54of the plug socket. The leaf spring-like mating contact13,14is situated in a receiving slot55of the plug socket8which is formed in a circumferential wall56of the plug socket8. The circumferential wall56delimits a receiving space42for the plug body5. The mating contact13,14is situated radially outside the receiving space42and protrudes by way of a free contact end58with a protrusion t through the receiving slot55in the circumferential wall56into the receiving space.FIG. 11shows the contact ends58of the mating contacts13,14, which contact ends protrude into the receiving space42.

The external contacts11,12(FIGS. 3, 4) interact with the mating contacts13,14, wherein, in addition to electrical contact being made between the external contact and the mating contact, a latching connection15is formed at the same time, as shown inFIG. 3.

The external contacts11,12and the mating contacts13,14are formed in accordance withFIGS. 14 to 17for the purpose of forming a latching connection15.

FIGS. 14 and 15show an external contact11; the external contact12is formed in a corresponding manner.

Each external contact11has a fastening end60by way of which the external contact is fixed in the material57of the plug body5. The fastening end60preferably has latching teeth61which advantageously establish a connection between the external contact11, which is held in the plug body5, and the plug housing21. The other, free end of the external contact11forms a fixing lug62which engages into an opening59in the plug body5, as shown inFIG. 9for example. The external contact11has a latching recess63in the region of the fixing lug62.

FIGS. 16 and 17show the configuration of a mating contact using the example of mating contact13. The mating contact14corresponds to the configuration of the mating contact13.

The mating contact has the approximate shape of an L with angled limb ends in side view. The first limb70of the mating contact13has—as shown inFIG. 17—a fastening opening71for engagement of a fastening screw72, as shown inFIG. 12. The mating contact is mechanically fixed to the base54of the plug socket8via the limb70.

The angled end73of the limb70is upright for the purpose of mounting a cable shoe. Furthermore, a further passage hole74is provided in the limb70, a centering pin75of the base54of the plug socket8engaging into the further passage hole.

The contact end58is formed at the free end of the mating contact13. The contact end58has an approximate V-shape in side view, as shown inFIG. 16. The contact end58has a rounded contact region76, wherein the contact end58ends in a stop tongue77. A housing stop78on the circumferential wall56of the contact socket8is associated with the stop tongue77, as shown, in particular, in the enlarged illustrations ofFIGS. 18 and 19.

The stop tongue77delimits, together with the housing stop78, the protrusion t (FIG. 11) of the contact end58into the receiving space42of the plug socket8, the protrusion being possible in the inoperative state.

As shown inFIGS. 18 and 19, there is a ramp80in front of the latching recess63in the external contact11or12in the insertion direction50of the plug body5into the receiving socket8. The ramp80begins at a height which corresponds approximately to the protrusion t of the contact end58into the receiving space42when the plug4is withdrawn. The ramp80rises to a height81which corresponds approximately to the outer circumference U of the plug body5. The height81is level with a top edge65of the latching recess63(FIGS. 14, 15).

When the plug4is inserted in insertion direction50, the plug end39axially enters the receiving space42of the plug socket8—assuming the plug body5is correctly associated with the plug socket8in respect of rotation position. The plug end39engages beneath the contact end58, with the result that the contact end can slide onto the ramp80and is driven radially outward in arrow direction64against a spring force. If the highest elevation of the ramp80is reached at the height81, the rounded contact region76of the contact end58slides on the outer circumference U of the plug body5, until the contact end58engages into the latching recess63. The contact end58which is situated in the latching recess63establishes an electrical connection between the external contact11and the mating contact13via the contact region76. The plug is mechanically locked in the plug socket8at the same time. The contact end58therefore forms a latching lug66, which engages into the latching recess63, at the same time.

The plug connection not only establishes a connection between power-transmitting first lines17,18, but at the same time a signal connection via two electrical lines19,20, in a reliable manner. In the process, the outside diameter of the plug connection can be kept small on account of the arrangement of the contacts.

Furthermore, the invention ensures that the plug is secured in the plug socket8in a mechanically fixed manner. The user has to overcome a latching force both when inserting the plug4into the plug socket8and also when withdrawing the plug4from the plug socket8. By way of example,FIG. 20shows the force profile, which has to be exerted by the user, in accordance with curve85. When the plug4is inserted into the plug socket8, the plugging force which has to be applied by the user increases moderately in accordance with curve85until the latching lug66meets the ramp80. The insertion force increases to a maximum86at which the latching lug66has slid onto the maximum height81of the ramp80. The latching lug66now engages into the latching recess63, wherein the force which has to be applied by the user drops sharply to zero. The process of overcoming the maximum86of the force profile in accordance with curve85provides the user with haptic feedback that the plug4is correctly inserted into the plug socket8.

A significant force profile in accordance with curve87inFIG. 21is also produced when unplugging the plug4. If the user pulls the plug4, he has to apply a maximum amount88of force as early as after a short distance before the plug4is released from the plug socket8. After the maximum88has been overcome, the force drops significantly, with the result that the user receives haptic feedback about the plug connection1being released.

The fluctuations in the force profile of the curves85,87shown inFIGS. 20 and 21are caused by superimposition of the forces occurring when inserting and, respectively, releasing the plug connection1by the plug contacts6,7and contact sockets9,10for the purpose of transmitting the electrical power and the external contacts11,12and mating contacts13,14for the purpose of signal transmission which are formed differently thereto.

The significant drop in force in curve85, shown inFIG. 20, after the maximum86, in particular to a negative force in the scale range of the x-axis between 9 and 10, is caused by the latching lug66being drawn into the latching recess63. This structural configuration and the resulting force profile ensure that the plug4necessarily always reaches an end position; stable intermediate positions are not possible. The negative force profile of the curve87after the maximum88, which negative force profile occurs when the plug connection1is disconnected, is the result of the ramp80on the plug body5. The maximum88is determined by the latching lug66lifting out of the latching recess63.

FIG. 22shows a perspective illustration of a mating contact13′, as is also illustrated inFIG. 17. Identical parts are provided with the same reference symbols.

In contrast to the configuration of the mating contact13in accordance withFIG. 17, the mating contact13′ inFIG. 22has an opening53in the contact region76. The opening53has an opening width W which extends in width direction K of the contact region76and is expediently equal to or advantageously greater than the width B (FIGS. 15, 24) of the external contact11. The opening width W of the opening53is smaller than the maximum width M (FIG. 24) of the contact region76. The maximum width M of the contact region76is measured in width direction K.

The opening53can have a round shape. Geometries which differ from the circular shape can advantageously be provided too. A circular shape, an elliptical shape, a square shape or a rectangular shape are preferred. In the case of an ellipse or a rectangle, the larger geometry axis extends in width direction K of the contact region76.

The function of the opening53can be identified in the enlarged illustration of the latching connection15between the plug body5and the plug socket of the plug connection1according toFIG. 23. The illustration inFIG. 23corresponds to that inFIG. 19; the same reference symbols are used for identical parts.

Owing to the opening53in the contact region76, the external contact11of the plug body5, which external contact is particularly in the form of a plug tongue, is situated in the opening area79of the opening53. The highest elevation67of the contact region76is situated higher than the opening area79of the opening53. The highest elevation67of the contact region76, which highest elevation is situated outside the opening53, is situated, in the contacted position according toFIG. 23, below the base69of the latching recess63, as shown inFIG. 23. The opening area79of the opening53is situated at a vertical distance a lower than the highest elevation67.

The opening53in the contact region76of the mating contact13, which is particularly in the form of a contact spring, can, at least by way of a subregion of its opening edge92, come to bear so as to make contact on the base69of the latching recess63. This is schematically illustrated inFIG. 24.

In a simple embodiment, at least the longitudinal edges82and83(FIGS. 15, 24) of the external contact11come to bear against the opening edge92so as to make contact. The bearing points94and95which make contact and are produced owing to the longitudinal edges82and83bearing against the opening edge92are illustrated inFIG. 24. At least one bearing point94or95is produced on at least one longitudinal edge82or83on account of the opening53. In particular, at least one bearing point94or95can be produced on one or the other longitudinal edge82and83. In a particular embodiment of the invention, in each case two bearing points94and95are produced on each longitudinal edge82and83, as a result of which electrical contact is made between the external contact11and the mating contact13by a total of four contact-making bearing points which ensure reliable signal transmission.

It may be advantageous to form the opening53in such a way that the opening edge92rests by way of two edge sections91and93on the base69of the latching recess63of the external contact11so as to make electrical contact. This is illustrated using dashed lines inFIG. 24. A first, front edge section91extends between the front bearing points94of the longitudinal edges82,83. A second, rear edge section93extends between the rear bearing points95of the longitudinal edges82,83. The contact-making edge sections91and93can also rest on the base69of the latching recess63so as to make only partial contact. The edge sections91and93advantageously rest on the base69of the latching recess63so as to make electrical contact over the entire subsection of the opening edge92.

The opening53is preferably situated centrally in the contact region76of the mating contact13. As shown in the schematic plan view according toFIG. 24, the opening53is expediently situated symmetrically in relation to the highest elevation67, in particular symmetrically in relation to the vertical line89of the highest elevation67.

Further advantageous embodiments are produced by any desired combination of the features of the above-described embodiments.