DE29607244U1 - Screw-on hinge for earthed control cabinet doors, equipment cladding or the like. - Google Patents

Description

DR.-ING. Ernst Stratmann

40212 PATENT ATTORNEY

D-XX)K)S DÜSSELDORF i · SCHADOWPLATZ 9 VNR: 109 126

Dusseldorf, 23 April 1996

9608 Gm

Dieter Ramsauer
42555 Velbert

Screw-on hinge for earthed control cabinet doors, equipment panels or the like.

The invention relates to a screw-on hinge for grounded control cabinet doors, equipment panels or the like, with two hinge parts made of metal, which are pivotably connected to one another by means of a hinge pin arrangement made of metal, wherein the hinge pin arrangement is mechanically firmly and electrically connected with one end in one hinge part, and extends with its other end or another area into the other hinge part.

Such a screw-on hinge is already known, for example, from catalog page 4-262 of the general catalog of the company DIRAK Dieter Ramsauer Konstruktionselemente GmbH & Co. KG, Kaiserstr. 55-59, 58332 Schwelm.

Such hinges are used, for example, to attach control cabinet doors to control cabinet housings, or to attach parts or flaps of equipment panels

Postal check: BERLIN west (bank code 10010010) 132736-IO9 · deutsche bank (bank code 3OO 70 0 10) 6I6O253

to be made pivotable in order to access certain machine parts within an apparatus casing.

It is becoming increasingly necessary to shield electrical or electronic equipment housed in a control cabinet, or enclosed electronic devices, from external electrical influences. Conversely, it is often mandatory to protect people and equipment from electrical fields emanating from electrical equipment housed within such control cabinets and equipment casings.

For good shielding, it is necessary, among other things, to create a good electrical connection between, for example, a door leaf made of electrically conductive material, such as sheet steel, and, for example, the associated door frame, which is also electrically conductive and is also made of sheet steel. This electrical contact must not have too high a resistance. The same applies to equipment casings, the individual parts of which must be electrically connected to one another, as well as to adjacent or load-bearing frame parts or struts that hold the individual equipment casing parts and mechanically connect them to one another.

In order to create this low-resistance electrical connection between, for example, different wall parts, which is necessary for good shielding, it is therefore necessary to create an electrical path between them. This is also necessary between the metal of a door leaf or machine casing on the one hand and the door frame or other parts of the machine casing on the other, which could be done, for example, using flexible cables that are connected in a suitable manner to the metal parts of the associated technical equipment. However, such cable connections are cumbersome to create and also impractical if, for example, a door leaf is dismantled.

·

-JLJL

- 3

or are to be removed, or if an appliance cover is to be removed and put aside, in which case the cable connection may have to be removed in a complicated manner. It could also be the case that such cable connections are forgotten or not installed correctly during reassembly or during initial assembly, so that the protective function or shielding is not present or inadequate without being recognized.

It is more advantageous to use existing connecting devices between, for example, the control cabinet door and the control cabinet frame or similar. Such existing devices are, for example, the hinges that connect the control cabinet door to the control cabinet frame or the equipment panel to neighboring panels or support frames for these equipment panels or that pivotably support them.

One could try to use known screw-on hinges, such as those mentioned at the beginning, for this purpose. For this purpose, for example, a version with a cast-in threaded pin or with a pressed-in threaded pin could be pushed through corresponding holes in the door leaf and then mounted using a fastening nut, whereby a fan-shaped washer could be inserted between the fastening nut and the surface of the door leaf, which, when tightened, digs through any layers of paint in the door leaf and reaches the metal surface of the door leaf, so that a perfect electrical contact can be made between the metal of the door leaf and the hinge part attached to this door leaf. The same applies to the switch cabinet frame and the other hinge part attached to it.

However, the contact between these two hinge parts is problematic, as it must also be low-resistance so that the desired low-resistance of the entire conduction path is ensured. Since the outer surfaces of these hinge parts are often painted, e.g. coated black, i.e. provided with an electrically insulating or at least poorly conductive paint layer, the contact between the two hinge parts that move relative to each other is not always guaranteed. It is possible to mechanically or electrically connect the hinge pin device, i.e. in particular a metal pin that passes through both hinge parts, to one hinge part so that the current transfer resistance between these two parts can be kept as small as desired, but the pin must remain movable in relation to the other hinge part so that due to play, bearing grease, dirt and the like, the electrical transfer resistance between this pin and the other hinge part that is movable relative to the pin (as well as between the hinge parts themselves) is not defined and can therefore be relatively high, so that the purpose of the security or the shielding ability may be missed.

The object of the invention is to design a hinge of the type mentioned at the beginning in such a way that these disadvantages are avoided and a sufficiently low ohmic contact resistance is always ensured between the two hinge parts. The arrangement should be such that external influences such as a surface coating of a non-conductive or poorly conductive paint or oxide do not impair the shielding function. Furthermore, an aggressive environment should also be able to be tolerated if necessary. Finally, a weakening of the strength of the hinge should be avoided if possible. Designs should also be possible in which the hinge can be removed, whereby the earthing function should be automatically restored after it has been hung in place .

» ■ » &Lgr; ft-· · · I >tt

The grounding contact should not deteriorate even if the hinge is operated frequently.

The problem is solved by providing an electrically conductive spring device which connects the metallic contact surfaces of the hinge pin mechanically and electrically firmly connected to one hinge part or of a part electrically connected to it with corresponding metallic contact surfaces of the other hinge part in a force-fitting and electrically conductive manner in all working positions of the hinge.

This measure ensures that the two hinge parts always have a defined mechanical and thus also electrical contact force against each other, which leads to a defined contact resistance that can be made as low as necessary.

Based on this basic concept, various embodiments are possible. For example, the hinge pin device can be made of two parts, with one hinge pin part of the hinge pin device being mechanically firmly or electrically connected to one hinge part (for example, pressed, welded or soldered), while the other hinge pin part is mechanically firmly and electrically connected to the other hinge part, with the preferably cylindrical spring element then ensuring the desired electrical connection and low contact resistance between these two hinge pin parts. For this purpose, the spring element could be a compression spring that is accommodated in an axial bore of one hinge pin part and extends to the contact surface of the other hinge pin part or hinge part. It is assumed that the contact surface between the spring and the two hinge pin parts is metallic, so that the

· 4

Pressure contact creates a correspondingly low contact resistance.

These contact surfaces can also be formed by the front surfaces of the two pin ends.

Alternatively, one contact surface can be formed by the front face of a pin attachment that extends into an axial bore of the other end of the pin. In this case, the spring element and its contact points would advantageously be enclosed by the pin and thus particularly well protected against, for example, ambient gases that may be corrosive, or against contamination by dust or lubricating oil that may be used to lubricate the hinge.

The spring element does not necessarily have to be a compression spring that generates axial forces; it can also be a cage spring that generates radial forces and is pushed onto the end that extends into the axial bore. The cage spring can use the wall of the axial bore as a contact surface, or the peripheral surface of the attachment. The contact surface can also be formed by the bottom surface of the axial bore. Instead of bringing the spring element into direct contact with a part of a hinge element that rotates relative to it, a metal ball can be arranged between them, which reduces the frictional forces and reduces signs of wear.

In particular, the spring element and the metal ball can be arranged in an axial bore formed by a hinge pin part or by a hinge part.

The invention is explained in more detail below using embodiments shown in the drawings.

* *_*__· &Lgr; LXtX,

7 -

It shows:

Fig. 1 shows a cross-sectional view of a hinge designed according to the invention according to a first embodiment in connection with a partially shown cabinet door which is attached to a cabinet frame;

Fig. 2 shows the hinge of Fig. 1 in a partially axially sectioned view in a plan view;

Fig. 3A shows one of the hinge parts, here connected to the cabinet frame;

Fig. 3B the second hinge part connected here to the door leaf;

Fig. 3C shows the hinge pin arrangement consisting of two hinge pin parts and a spring in an exploded view;

Fig. 4 shows a further embodiment of a hinge according to the invention in a view similar to Fig. 1;

Fig. 5 shows the hinge according to Fig. 4 in an axial sectional view;

Fig. 6A , 6B and 6C

in exploded views the individual parts of the hinge according to Fig. 5;

Fig. 7 is a view similar to Fig. 1 of another hinge arrangement;

Fig. 8 is a partially axial sectioned view of the

9A, » ···· * · ····· · ··♦ · ·
• · · ♦ · ·»·
···· · «· · ·· ··
- 8th - Hinge according to Fig. 7; Fig. 9B and 9C 10 the individual parts of the system shown in Fig. 8 Hinge in separate representation; Fig. 1 1 in a view similar to Fig. 1 another Hinge; Fig. an axial sectional view of a first embodiment 12 form of the illustrated in Fig. 10 hinge; Fig. an axial sectional view of a second embodiment 13A form of the illustrated in Fig. 10 hinge; Fig. and 13B 14 the two hinge parts, as used in the Hinges of Fig. 11 and 12 can be used; Fig. 15 the hinge pin arrangement of the hinge of the Fig. 11 in exploded view; Fig. 16 the hinge pin arrangement of the hinge of the Fig. 12 in exploded configuration; Fig. yet another embodiment of the inventive 1 7 hinge in a view similar to the 18A Fig.1; Fig. an axial sectional view of the hinge of Fig.
16; Fig. , 18B and 18C the individual parts of the hinge according to Fig. 16

- 9 and
17 in an exploded view;

Fig. 19 shows, in a representation similar to Fig. 1, yet another embodiment of a hinge designed according to the invention;

Fig. 20 is a sectional view of the embodiment according to Fig. 19 along the hinge axis;

Fig. 21A, 21B and 21C

the individual parts of the hinge shown in Fig. 19 and 20 in exploded form;

Fig. 22 is an enlarged detail from Fig. 20; and

Fig. 23 is an enlarged detail from Fig. 21C, here showing a cage spring.

In Fig. 1, in a view from above, and in Fig. 2, in a plan view, a screw-on hinge 10 can be seen, with which, for example, a door leaf 12 made of folded sheet steel can be attached to a door frame or door casing 14 also made of sheet steel. Instead of a door leaf 12, it can also be a flap 12 that closes an opening in a machine housing 14, or a housing wall part that is attached to a frame so that it can be folded away.

As can be seen from the exploded view of the parts of the hinge in Fig. 3A to 3C, the screw-on hinge consists of two hinge parts 16, 18, which are pivotally connected to one another by means of a hinge pin arrangement 20, shown in Fig. 3C, according to Fig. 1 and 2. The axis of the hinge pin arrangement 22 lies slightly in front of the outer plane 24 of the two hinge parts,

**«* &bgr;** 11 4 «

■ &idigr; 9 £ &bgr; SS ¥ 5 % · *

- 10

see Fig. 1, which allows an opening of 180°.

The hinge part 16 is attached to the door frame 14 or the door leaf 12 at points 26, 28 and the hinge part 18 at points 30, 32, see Fig. 2, whereby the attachment could be carried out, for example, by means of countersunk screw devices 34, whereby between the fastening nut 36 and its support on, for example, the door frame sheet 14, reference number 38, a means for reducing the contact transition resistance can be used, such as a spring washer or fan washer 42, which digs through any oxide or paint layers that may be present and reaches the metal surface and thus ensures a low transition resistance, which leads via the nut 36 to the screw bolt 34, further via its screw head 40 to the hinge part 16, so that overall there is a low transition resistance between the door frame part 14 or housing frame part 14 on the one hand and the hinge part 16 on the other hand. can be ensured. Alternatively or correspondingly, a threaded pin 134 could also be provided, which may be cast into the hinge part 18 according to Fig. 1 and which, by means of a nut with a spring washer 42 or the like placed between them, creates a low transition resistance between the door leaf 12 on the one hand and the hinge part 18 on the other hand.

For optical reasons or for reasons of corrosion resistance, not only the material of the control cabinet, i.e. the surfaces of the door leaf 12 and door frame 14 (or of the flap 12 and machine housing 14) are painted, but also the surfaces of the hinge parts 16, 18, however, it is usually ensured that the threads of cast-on threaded pins 134 remain metallically bright (for example, by covering them during the painting process), just as it can be achieved that

9 9

·

- 1 1 -

the electrical contact between the screw head 40 and the corresponding recess in the hinge part 16 is or is made free of layers of paint.

In order to ensure that the control cabinet door leaf 12 and the control cabinet door frame 14 have the desired shielding properties, it is necessary that they have a low overall electrical contact resistance to one another, which in turn means that the two hinge parts 16, 18 must have a low contact resistance to one another. This cannot be achieved simply by having the interlocking projections 44, 46 and 48, 50 carrying the hinge pin holes touch one another, since the contact surfaces can have play with one another, can be contaminated by dirt or paint residues or grease or oil, which can also contribute to the contact resistance of the contact between these finger-like projections being undefined and can therefore be high.

In order to obtain the desired low, defined transition resistance, a specially designed hinge pin arrangement 20 is provided according to Fig. 3C, which is arranged with its one end 52 in a mechanically strong and electrically conductive manner in one hinge part 18, which can be achieved by welding, soldering or simply, as here, by pressing this grooved end 52 into a corresponding hole 54 in the joint projection 48 of the hinge part 18, for example by providing the pin end 52 with a groove or knurling which digs into the peripheral walls of the hole 54 when the pin is driven into this hole and creates good electrical contact with the material of the hole wall. The hinge pin device 20 extends into the other hinge part, even if it is divided, as in Fig. 3C. Because it is connected to one of its parts, at

- 12 -

for example with the part 56, extends into the corresponding hinge hole 58, as can be seen in Fig. 2, a sufficiently good shear strength is obtained between the two hinge parts.

In the hinge pin arrangement shown in Fig. 3C, another partial pin 60 is present, which is mechanically firmly and electrically connected to the other hinge part 16, for example again by means of a knurling 62 at one end, with which this pin, as can be seen in Fig. 2, is pressed into the opening 64 of the hinge part 16. Here too, the partial pin 60 extends into the bore 66 of the other hinge part 18 and thereby provides mechanical strength against shearing.

As a result of the measures described, the two pin parts 56, 60 are each electrically connected to the frame 14 or the sheet 12 of the control cabinet or the like, so that it now only has to be ensured that the two pin parts 56, 60 also have a defined low-resistance electrical connection to one another. This is achieved by an electrically conductive spring device 68, which, in the assembly position shown in Fig. 2, rests against the two end faces 70, 72 of the two pin parts 52, 60 in a spring-loaded manner and thereby achieves the desired low-resistance contact between these two parts.

The spring 68 is expediently designed in such a way that it is accommodated without great radial play in the opening space that remains in the hinge inserts 44, 50 between the pin parts 56, 60, so that it does not tilt, whereby a uniform contact system is maintained even when the two hinge parts and thus the two pins 56, 60 move towards each other.

The arrangement and design of the individual hinge parts

according to the embodiment of Fig. 1 to 3 is essentially symmetrical, so that the individual parts are interchangeable.

The hinge can also be easily switched from right to left.

In principle, this also applies to the embodiment according to Figs. 4 to 6, even if the two hinge parts 116, 118 are only symmetrical in terms of their fastening, but not in the area of their mutual connection. Thus, the hinge part 116 has two projections 144, 146 forming the holes for the hinge pin arrangement 120, while the hinge part 118 has only one such projection 148, which is enclosed by the projections 144, 146 of the other hinge part 116 after the hinge 110 has been assembled.

The hinge pin arrangement 120 here also consists, see Fig. 6C, of two partial pins 156, 160 and a compression coil spring 168. In order to produce a mechanically strong and electrically conductive connection between the two pin parts 156, 160 and thus the respective hinge part 160 or 118, the pin 356 shown below in Fig. 6C is turned over in such a way that it points with its grooved end upwards and thereby comes into contact with the hinge pin bore 154 of the hinge part 118 in the desired manner, while the partial pin 160 with its upper grooved end 162 comes to rest firmly and electrically conductively in the hinge pin bore 164 of the hinge part 116.

The two hinge pin parts 160, 156 are in turn connected to one another in an electrically conductive manner by means of a compression spring 168 in the manner already described. This also ensures in the design according to Figs. 4 to 6.

ensures that the two hinge parts 116, 118 and thus the cabinet parts attached to them, such as the door leaf, flap or door frame, machine housing, are connected to one another via a low electrical resistance.

In the embodiment shown in Figs. 7 to 9, the two hinge parts 216, 218 each have only one projection 246 or 248 that receives the hinge pin. Such a hinge can thus be unhooked without having to completely remove the hinge pin device.

The hinge pin 256 in turn has a grooved free end 252 in order to drive it into the hinge hole 254 of the hinge part 218 in a mechanically secure and electrically conductive manner, for example. The spring arrangement 268 also present here could have a similar shape, as can be seen in Figs. 1C and 3C, for example, i.e. with an outer circumference that corresponds approximately to the inner diameter of the hole 164 of the hinge part 216, possibly slightly smaller. This could be done in particular by designing the hinge pin hole 264 of the hinge part 216 as a blind hole, as can also be seen in Fig. 9A, with one end of such a spring arrangement resting on the inner end of this blind hole, while the other end then rests on the end face 270 of a pin 256 extending into this blind hole 244 (not shown).

However, in order to make the hinge pin 256 as long as possible and at the same time to give the spring 268 sufficient longitudinal extension, and also to ensure that the spring 268 is not easily lost when the hinge can be removed, it is advantageous to provide an axial bore in the front surface area 270 , reference number 271, into which a spring 268 with a reduced diameter can be inserted, which then rests with one end on the bottom of the blind bore.

- 15 -

271, and with its other end touches the bottom of the blind bore 264, as shown in Fig. 8.

If blind holes are not required, the two hinge parts of a detachable hinge can be equipped with through holes 364, 354 as shown in Figs. 10 to 15, 316, 318. This has the advantage, among other things, that the two hinge parts are again constructed identically, which reduces manufacturing costs and reduces the storage of the hinge parts. The associated hinge pin arrangement 320 or 320' is shown in Figs. 14 or 15 and here again comprises a partial pin 356 which can be anchored firmly and electrically conductively in the hole 354 of the hinge pin part 318 via a groove 352 in the manner already described, and which is long enough to reach into the hole 364 of the other hinge part 316, as can be seen in Figs. 11 and 12. Another shorter hinge pin part 360 also has a knurling 362 and can thus be pressed into the hole 364 of the hinge part 316 in an electrically conductive manner, as shown in Figs. 11 and 12. It would now be possible to arrange a spring between the end faces 370, 372 of the two partial pins 356, 360, as shown for example in Figs. 2 and 3C. However, in order to be able to make the hinge pin parts as long as possible and thus increase the shear strength of the hinge, it is advantageous to instead arrange a blind hole 373 in one of the two partial pins, here it is the partial pin 316, into which a spring arrangement, here in the form of a compression coil spring 368, can be inserted, which in turn is supported on the one hand on the bottom of the blind hole 373, and on the other hand on the end face 370 of the opposite partial pin 356. This arrangement is shown in Figs. 15 and 12.

In order to improve the contact even during frequent turning operations, it is sometimes advisable to add a ball

350, which are fitted into the blind hole 373

and improved, less frictional contact

between the spring 373 and the dividing pin 356, see Fig. 14 and 11.

The hinge parts of the embodiment according to Fig. 16 to 18 have a similar shape to that seen in the embodiment according to Fig. 1 to 3. What is different here is the hinge pin arrangement 420, which is designed in such a way that it is present on all three transition surfaces between one hinge part to the other hinge part, in contrast to the embodiment according to Fig. 2, in which the spring arrangement 68, which does not absorb any shear strength, is present on the middle transition surface. The higher strength in Fig. 17 is achieved in that the one partial pin 456 has a projection 80 starting from its end face 470, which can be fitted into a blind hole 81, which is provided by the other partial pin 460 starting from its end face 472. At the inner end of this blind hole, a spring device 468 is provided, which is placed between the front surface of the projection 80 and the bottom surface of the blind hole 81 and thus creates contact between the two partial pins 450, 460. These partial pins are in turn firmly and electrically connected to the two hinge parts 416, 418 via corrugations in the manner already described, see also Fig. 17. Preferably, the length of the partial pin 460 on the one hand and that of the part of the partial pin 456 that is not reduced in diameter is selected such that the gap 83 remaining during assembly between the front surfaces 470 and 472 is located approximately in the middle within a projection 244 of one hinge part 416 and this does not result in a reduction in the shear forces that can be absorbed.

Instead of a spiral compression spring 468, a cage spring 468 can also be provided as shown in Fig. 21C, which is shown in Fig. 23

is made even clearer. This cage spring can be pushed onto a recessed area 84 of the projection 85 extending from the front face 570 and, when the pin 556 is inserted into the blind bore area of the pin 560, it rests against the inner walls of the pin, as shown enlarged in Fig. 22. Compared to the embodiment of Fig. 18C, the embodiment according to Fig. 21C has the advantage that an increased number of contact points, for example four contact points on the inner wall of the bore 81, can ensure even lower resistance.

Claims (1)

Screw-on hinge for earthed switch cabinet doors, equipment panels or the like, with two hinge parts (16, 18) made of metal, which are pivotably connected to one another by means of a hinge pin arrangement (20) made of metal, the hinge pin arrangement (20) being mechanically firmly and electrically connected with one end (52) in one hinge part (z, B,- 18) and extending with its other end (zi B ₅ 70) or another area into the other hinge part (16), characterized in that an electrically conductive spring device (68) is provided which connects metallic contact surfaces (70, 72) of the hinge pin (56) mechanically and electrically connected with one hinge part (1Θ) or of a part (z, B, 80) electrically connected thereto with corresponding metallic contact surfaces*? of the other hinge part in a force-fitting and electrically conductive manner in all working positions of the hinge, Screw-on hinge according to claim 1, characterized in POSTAL CHECK: berlin west (bank code iOOlOOIO) 30-109-DEUTSCHEBANK(BLZSOOyOOlO) 616O253 O · · characterized in that the hinge pin device is in two parts (Fig. 3C, Fig. 6C, Fig. 14, Fig. 15, Fig. 18C, Fig. 21C), wherein one hinge pin part (ζ. β. 56) is mechanically firmly and electrically connected to one hinge part (e.g. 18) {such as pressed, welded, soldered), while the other hinge pin part (e.g. 60) is also mechanically firmly and electrically connected to the other hinge part (e.g. 16), and that the spring element (e.g. 68) preferably represents a spring having a cylindrical shape, such as a compression spring or cage spring (e.g. 68), which is received in an axial bore (58, 66) of at least one hinge part (16; 18) and contact surfaces of the one hinge pin part (ζ. B. 70) with contact surfaces of the other hinge pin part (&zgr;. B. 72) or the other hinge part (&zgr;. &Bgr;, 264). Screw-on hinge according to claim 2, characterized in that the contact surface is formed by the end face of the end of the hinge pin (70, 72) or the ends of the hinge pin parts. Screw-on hinge according to claim 2, characterized in that the contact surface is formed by an end face of a hinge pin part extension (80) which extends into an axial bore (81) of another hinge pin part (460). Screw-on hinge according to claim 2, characterized in that the contact surface is formed by the peripheral surface (84) of a hinge pin part extension (85) which extends into the axial bore of another hinge pin part (65), the spring element being a cage spring (568) which is pushed onto the extension (85, 84). 6, screw-on hinge according to claim 2, characterized in that a metal ball (350) which reduces friction is arranged between the spring element (368) and the contact surface (370), 7, screw-on hinge according to claim 6, characterized in that the spring element (368) is arranged in an axial bore (373) which is formed by the one hinge pin part (360) or by a hinge part (216)