HK1095422B - Arrangement used to fix conductor rails for multi-phase switchgears - Google Patents

Description

Device for fixing contact rails of multiphase switching device

The invention relates to a device for fixing a contact rail of a multiphase switching device, in particular a contactor.

The contact rail in a polyphase electrical switching device has a terminal at its outer end and is connected directly or indirectly with its inner end to a fixed contact piece which is connected to and disconnected from a movable contact piece. It is already known to encapsulate the contact rails by pressing or injection molding (DE 19904355 a1), by gluing (DE 10036350 a1), by screwing with (DE 29604726U 1) in the switchgear housing, with (DE 19814410a1) in the screw plate or with (DE 3232173C 2) in the contact rails, by embedding (DE 10061394 a1) or by riveting with the aid of a housing part (EP 645792 a1) provided for this purpose in the switchgear housing.

A disadvantage of these known devices for fixing the contact rail is that the high technical costs for the equipment, tools and operating time for the fixing and the partial, only conditional and laborious disassembly of the contact rail are not possible, only possible partially. For example, a user who wants to replace a worn contact with a new contact, as suggested by the manufacturer, must remove at least six screws and their six locking elements and re-fix them in a three-phase contactor with screwed contact rails. The bonding of the contact rails requires a pretreatment of the surfaces and a curing time. The bonded portion causes an increase in cost when reused.

The object of the invention is therefore to provide a simple assembly and disassembly of a busbar.

This object is achieved according to the invention by a device of the type mentioned at the outset, in that the invention proposes a device for fixing a contact rail of a polyphase switchgear, in which the incoming and outgoing contact rail fixed in the switchgear housing has a terminal at its outer end and the contact rail has a fixed contact piece at its inner end, which is in operative connection with a movable contact piece, characterized in that:

the switchgear housing has a linear guide for receiving the contact rail into its installation position,

each contact rail has a through-opening which, in the installed position, coincides with a receiving opening formed in the switching device housing, and

the pins extend through the through holes into the associated receiving holes and are combined with a lug to form a plug-in comb, which is made of insulating material.

The linearly formed guide and receiving openings in the switching device housing, the through-openings in the contact rails and the plug-in combs on each connection side result in a device for fastening the contact rails, which can lead to a stable fastening of the contact rails with little translational engagement movement. This makes it easy to automate the fixing of the contact rail. The device according to the invention requires neither an internal thread in the contact rail or in the switchgear housing nor a thread plate and can eliminate the anti-loosening elements required for screw connections. By eliminating the iron parts, no adverse magnetic influence on the flow guidance on the contact rail is produced. Both the final fixing and the removal of all contact rails on a connection side are achieved by inserting or removing the plug-in comb into or out of the through-and receiving holes with a handle. When the switching device housing cover is removed, only two simple and quick operations per connection side are required for the tool-free mounting or dismounting of the contact rail. The bayonet comb is much easier to operate than a small screw and a locking piece. For easy recycling, the bayonet comb is injection-molded from a renewable material under pressure. The use of a plug-in comb made of insulating molding material makes it very easy to comply with the required air gap and creepage distances. This problem is of increasing importance as switching devices tend to be of smaller and smaller size. The web surface of the bayonet comb can be used in a suitable manner to apply a prompt to the user.

The plug-in comb can expediently be clamped with its plug in the through-hole or/and pressed by the switching device housing cover.

One desirable configuration of the bayonet comb is a cylindrical or prismatic configuration of the plug, the through-hole and the receiving hole, for example with a circular or polygonal cross section. An advantageous embodiment consists in a plug which is provided with a longitudinal slot and which serves to form a positive connection between the through-hole and the receiving hole, which connection forms a power transmission chain. The bevel on the free end of the plug facilitates the introduction of the through-hole and the receiving hole.

An advantageous embodiment of the plug consists in providing compensation slots in the connecting webs for improved tolerance compensation of the distance between the receiving bores. For improved handling, a handle-shaped configuration on the web is advantageous.

In order to prevent the contact rail inserted into the guide from falling out before the insertion of the plug-in comb, the contact rail is provided with projections, which form a clamping connection with the guide when the contact rail is inserted into the guide.

An advantageous development of the device consists in that receiving slots are formed in the phase separating walls of the switchgear housing, i.e. the separating walls separating the phases, which slots support the inserted plug-in combs parallel to the connecting direction by means of connecting webs and thus contribute to an increase in the permissible tensile and compressive forces on the connecting terminals. In this case, the webs provided with the compensating slots and the phase separating walls provided with the receiving slots expediently form a cruciform fit in a staggered manner with respect to one another.

Further details and advantages of the invention can be obtained from the following exemplary embodiments which are illustrated by means of the figures. The attached drawings show that:

FIG. 1: a further embodiment of the inventive fastening device with the inventive details is shown in a longitudinal section of the switching device;

FIG. 2: is an exploded perspective view of the device according to the invention;

FIG. 3: is an assembled perspective view of a device according to the present invention.

In the figures, a device for fixing a contact rail is shown, in which a multipole switching device 2 in the form of a three-pole contactor is present, which is essential for the description of the invention. The switching device 2 is surrounded by a switching device housing 4, of which only the upper part is shown in the figure. As shown in fig. 1, the switching device housing 4 is closed on the front side by a removable housing cover 6. In the switching device housing 4, an incoming and an outgoing contact rail 8 are fixed for each current phase. Each contact rail 8 has a terminal 12 at its outer end, which extends into the corresponding connection chamber 10, and a fixed contact 14 at its inner end. The contact rails 8 belonging to a current phase are connected or disconnected electrically in the usual manner by means of a contact bridge, not shown, the fixed contact 14 being connected or disconnected to the movable contact fixed on the contact bridge.

In the switchgear housing 4, as shown in fig. 2, slot-shaped guides 16 are formed opposite one another in pairs on each connection side for each current phase. The plate-shaped intermediate portion 18 of the busbar 8 is inserted between the guides 16 to such an extent that it rests on the end face 20 of the guide 16 in the mounted position of the busbar 8 shown in fig. 1 and 3. Each contact rail 8 has a through-opening 22, which in the installed position coincides with a receiving opening 24 formed in the switching device housing 4. The busbar 8 is provided on its central section 18 with projections 25 which are pressed out on the edge and which, when the busbar 8 is introduced into the guide 16, lead to a clamping action which is sufficient to prevent the busbar 8 from sliding out of the guide 16 during transport during the production of the switching device 2.

Also associated with the fastening device is a plug-in comb 26 made of insulating molding material for each connection side. The plug-in comb 26 has a cylindrical plug 28 for each current phase. The pins 28 belonging to a connecting side are connected to one another by a plate-shaped web 30. The plug 28 extends in one direction from the connecting piece 30. The connecting web 30 is provided with a handle 32 which is arranged on the opposite side with respect to the projecting plug 28.

In order to fix the contact rails 8 in their installation position, the plug-in combs 26 are inserted with their pins 28 through the through-openings 22 of the contact rails 8 into the receiving openings 24 of the switching device housing 4 in a clamping manner. For ease of insertion, the plug 28 is provided with a lead-in chamfer 34 on its free end. In order to be able to compensate for tolerances between the geometric spacings of the receiving bores 24 and the bolts 28, the connecting web 30 is formed between the bolts 28 with compensation slots 36 which open downwards, as shown in the drawing. In its assembled position, the plug-in comb 26 is additionally pressed by the overlying housing cover 6.

The switching device housing 4 has a longitudinally extending continuous inner phase separation wall 38. On each connecting side, as shown in the drawing, a receiving slot 40 is formed in the separating wall 38, which is open upward and which always lies in one plane with the receiving opening 24. The receiving slot 40 receives the connecting lug 30 of the inserted plug comb 26. In this case, on the one hand, the wall portions of the separating walls 38 adjacent to the receiving slots 40 act on both sides of the web 30 at right angles thereto, and, on the other hand, the wall portions of the web 30 adjacent to the compensating slots 36 act on both sides of the separating walls 38. In this way, the plug-in comb 26 forms a cruciform connection with the switching device housing 4.

The portion of the contact rail 8 in the switching device housing 4 forms a force transmission chain and a partially positive connection, i.e. on the one hand, by means of the cooperating units: the intermediate part 18, together with the guide 16 and on the other hand via the cooperating units: the receiving hole 24, the plug 28 and the through hole 22 achieve a simple, reliable and problem-free detachable fastening device. The plug 28 is subjected to shearing action, particularly when the joint sides are loaded in tension. The cross-section of the plug 28, in combination with the selected material, is dimensioned such that it can withstand the expected loads. The plug comb 26 is as tolerant as possible by the geometric configuration shown. Differences in the distance between the switchgear housings 4 in the range of tenths of a millimeter can be overcome without problems by the plug comb 26. In order to divert the attention of the user who is removing and installing towards the plug-in comb 26, it is advisable to have a distinctly different color design of the component relative to the switching device housing 4.

The invention is not limited to the embodiments described above, but also encompasses all embodiments which have the same function in the sense of the invention. The invention can thus also be constructed, for example, in such a way that the plug is slotted along its longitudinal axis with a single slot or a cross slot in order to create a resilient clamping force.

Claims (11)

1. Device for fixing contact rails of a polyphase switchgear, in which incoming and outgoing contact rails (8) fixed in a switchgear housing (4) have a connection terminal (12) at their outer end, the contact rails (8) have a fixed contact piece (14) at their inner end, the fixed contact piece (14) being in operative connection with a movable contact piece, characterized in that:

the switchgear housing (4) has a linear guide (16) for receiving the contact rail (8) in its installation position,

-each contact rail (8) has a through-opening (22) which, in the installed position, coincides with a receiving opening (24) formed in the switching device housing (4), and

the pins (28) extend through the through-holes (22) into the associated receiving openings (24) and are combined with a connecting piece (30) to form a plug-in comb (26), the plug-in comb (26) being made of an insulating material.

2. The apparatus of claim 1, wherein: the bolts (28) are clamped in the receiving bores (24).

3. The apparatus according to claim 1 or 2, characterized in that: the plug-in combs (26) are pressed by a switching device housing cover (6).

4. The apparatus according to claim 1 or 2, characterized in that: the plug (28), the through hole (22) and the receiving hole (24) are cylindrical or prismatic.

5. The apparatus according to claim 1 or 2, characterized in that: the plugs (28) are slotted along their longitudinal axes.

6. The apparatus according to claim 1 or 2, characterized in that: the plug (28) has a lead-in chamfer (34) at its free end which passes through the through-hole.

7. The apparatus according to claim 1 or 2, characterized in that: the connecting piece (30) has, between the pins (28), a compensating slot (36) which extends parallel to the pins (28) and is open on the side of the front end in the insertion direction.

8. The apparatus according to claim 1 or 2, characterized in that: a handle (32) is formed on the connecting piece (30) and is located on the opposite side with respect to the plug (28).

9. The apparatus according to claim 1 or 2, characterized in that: the contact rails (8) have projections (25) which form a clamping connection with the guides (16).

10. The apparatus according to claim 1 or 2, characterized in that: a receiving slot (40) for receiving the connecting piece (30) is formed on a phase separating wall (38) of the switching device housing (4).

11. The apparatus of claim 10, wherein: the connecting piece (30) has compensating slots (36) which form a cross connection with the receiving slots (40).