DE20003480U1 - Trailer coupling for a vehicle, in particular for a passenger car - Google Patents

Description

Trailer coupling for a vehicle, in particular
for a passenger car

The innovation concerns a trailer coupling according to the preamble of claim 1.

DE 93 11 906.2 Ul discloses a trailer coupling for passenger cars which has a coupling shaft. This coupling shaft is bent upwards at its rear end and is equipped with a coupling member in the form of a ball. The coupling shaft is supported in a tubular holder so that it can be moved longitudinally and rotated. It has an annular groove at the front end which interacts with a bolt of the holder and ensures that the coupling shaft is locked in a coupling position. By turning the coupling shaft by 90°, the annular groove disengages from the bolt so that the coupling shaft can be removed from the holder.

-2-

can be pulled out if the coupling is not needed.

The innovation is based on the task of creating a trailer coupling of the type mentioned above with simplified operation.

This problem is solved according to the innovation with the features of claims 1, 4, 5 or 12.

The trailer coupling according to claim 1 is particularly suitable for passenger cars and has a coupling shaft which is adjustable between a coupling position and a storage position. While the coupling member is directed backwards and upwards in the coupling position, it points forwards and to the side in the storage position, so that the coupling shaft no longer protrudes beyond the rear of the vehicle in the storage position. The coupling shaft is therefore supported in a holder firmly connected to the vehicle both in the coupling position and in the storage position, so that the coupling shaft does not have to be stored separately in the vehicle in the event that the trailer coupling is not required. In order to transfer the coupling shaft from the storage position to the coupling position, it only has to be pivoted and rotated in the longitudinal direction so that the coupling member points backwards and upwards. The coupling shaft is then locked in the holder so that the coupling member can transfer the tensile and compressive forces to the vehicle. Since the

Since the coupling shaft only needs to be swiveled and twisted in the holder, it is not necessary to thread the coupling shaft into the holder, which would be relatively difficult, especially in the dark. In the storage position, the coupling link protrudes forwards and to the side, so that it does not restrict the clearance of the vehicle to the ground in any way.

In order to achieve a simple pivoting of the coupling shaft, it is advantageous according to claim 2 to support it in the holder so that it can pivot about an approximately horizontal axis. The coupling shaft can easily be pivoted about this horizontal axis by approximately 180° in order to be transferred from the rear coupling position to the front storage position.

A particularly simple and at the same time effective support for the coupling shaft is provided in claim 3. The coupling shaft is held in a pipe section which is pivotably supported on the bracket in pivot bearings. The pipe section provides the coupling shaft with sufficient support so that lateral sliding or pivoting movements are reliably excluded. In particular, the tensile and compressive forces introduced into the coupling member can be easily supported via the pipe section.

Especially with heavy trailer loads, the weight force exerted on the coupling element is relatively high, which leads to a correspondingly high load on the bracket. The bracket must therefore fit very precisely to the coupling

-4-

shaft in order to avoid damage to the holder due to this weight. This makes the longitudinal displacement of the coupling shaft relatively stiff, so that attaching and removing the coupling is complex. It is therefore proposed according to claim 4 to support the front end of the coupling shaft on the top on a freely rotating roller. This roller takes on the support of the weight of the trailer transferred to the coupling member, the front end of which is pressed upwards due to the pivot bearing, although the longitudinal displacement of the coupling shaft is smooth due to the free rotation of the roller. It is important here that the roller is freely rotatable about an axis that is aligned perpendicular to the coupling shaft, since this is the only way to ensure smooth displacement of the coupling shaft.

In order to ensure a safe transmission of the pushing and pulling forces transmitted from the trailer to the coupling element, the coupling shaft must be securely locked to the bracket. Nevertheless, the coupling shaft must be easy to move from the coupling position to the storage position and vice versa. These requirements are advantageously met according to claim 5 by providing a hole on the rear of the bracket which is aligned with a hole in the coupling shaft in the coupling position. These aligned holes are penetrated by a locking pin which firmly connects both parts together. In order to easily insert the locking pin into the hole

-5-

the holder, it has the shape of a circular section when viewed in cross-section, with the hole in the holder being accessible from the outside via a channel. This channel is smaller than the diameter of the hole and larger than or equal to the height of the cross-section of the locking pin. This allows the locking pin to be easily rotated into a release position in which it can be pushed through the channel until it reaches the area of the hole. The locking pin is then rotated about its longitudinal axis into a locking position so that its effective cross-section is wider than the channel. This means that the locking pin can no longer slide out through the channel of the holder, so that the coupling shaft is firmly connected to the holder. However, this locking can be released very easily by rotating the pin again, so that the coupling shaft can very easily be transferred from the coupling position to the storage position and vice versa. Preferably, the locking pin can be fixed in the locking position to prevent unintentional rotation into the release position.

In order to further improve the fixing of the coupling shaft, it is proposed according to claim 6 to form the locking pin with a circular section in the area of one end. This circular section has approximately the diameter of the hole in the holder, so that when this circular section penetrates into the hole in the holder, the locking pin locks the coupling shaft regardless of its rotational position. The

-6-

The locking pin is pressed into the locking position by a spring, so that the coupling shaft is already locked when the locking pin has entered the hole. To release this locking, the locking pin simply has to be pressed or pulled against the force of the spring and then rotated around its axis until the circular section of the locking pin fits through the channel of the holder. The coupling shaft together with the locking pin can then simply be pulled out of the holder.

In order to be able to easily rotate the locking pin or to move it longitudinally against the force of the spring, it is advantageous according to claim 7 if the locking pin is connected to a gripping part. This gripping part preferably has the shape of a handwheel or a rotary knob with a structured surface in order to be able to easily transfer the required forces and torques to the locking pin.

In order for the driver of the vehicle to be able to easily check whether the coupling shaft is properly locked, it is proposed according to claim 8 to assign a signalling device to the locking pin. This checks the position of the locking pin and emits a signal when it is in the locking position. However, this signal is not emitted if the locking pin is not installed or is in the release position. The emitted signal can, for example, be generated by an opening

-7-

or closing switch and is preferably used to control an indicator light.

In order to secure the coupling shaft in the storage position, it is advantageous according to claim 9 to provide a locking device on the front of the bracket. This front locking device only has to secure the coupling shaft in the storage position without having to support the pulling and pushing forces of a trailer. This locking device can therefore be designed relatively simply.

Preferably, the locking device according to claim 10 is formed by a spring-loaded pin which passes through a bore in the holder. In a locking position, this pin penetrates into the bore of the coupling shaft, so that no additional fastening means are required on the coupling shaft.

In particular, if the coupling shaft is rotated by approximately 90° around the longitudinal axis of the coupling shaft in the storage position compared to the coupling position, it is advantageous according to claim 11 if the front and rear holes of the holder are offset from each other by approximately 90°. This allows the hole in the coupling shaft to be secured for locking both in the coupling position and in the storage position without the coupling shaft being weakened by multiple holes.

c · e i

• · ♦ · S

t » · i

The coupling shaft must be sufficiently stable to be able to safely support the tensile and thrust forces transmitted by the trailer. This requires the coupling shaft to be made from a solid material or a relatively thick-walled tube, which has a negative effect on the weight of the coupling shaft. However, since the coupling shaft has to be moved and possibly removed when it is transferred to the coupling or storage position, the aim is to make the coupling shaft as light as possible. To solve these contradictory requirements, it is proposed according to claim 12 to design the coupling shaft as a tube into which an I-, T- or �EEgr; beam is inserted. This beam has a vertical middle leg, which gives the coupling shaft a particularly high bending stiffness in the vertical direction. This means that despite its low weight, the coupling shaft can also transfer high support loads on the coupling member to the bracket and thus to the vehicle body without being permanently deformed.

An advantageous further development of the coupling shaft is shown in claim 13. The tube has an elliptical cross-section with a vertical main axis, so that the tube is particularly rigid in the vertical direction. The tube supports the effect of the inserted carrier.

The subject matter of the innovation is explained by way of example using the drawing, without limiting the scope of protection.

-9-

It shows:

Figure 1 is a spatial representation of a trailer coupling according to the innovation,

Figure 2 is a side view of the trailer coupling according to Figure 1,

Figure 3 is a sectional view of the trailer coupling according to Figure 2 along the section line III-III,

Figure 4 is a sectional view of a first embodiment of a coupling shaft,

Figure 5 is a sectional view of a second embodiment of a coupling shaft,

Figure 6 is a sectional view of a third embodiment of a coupling shaft and

Figure 7 is a sectional view of a fourth embodiment of a coupling shaft.

Figure 1 shows a spatial representation of a trailer coupling 1 consisting of a coupling shaft 2 and a bracket 3. The coupling shaft 2 is essentially tubular and bent upwards at its rear end 4. A coupling member 5 in the form of a ball is attached to this rear end 4, which serves to connect to a drawbar of a trailer.

The bracket 3 is formed by a U-shaped bent sheet metal part 6 in which holes 7 are provided. These holes 7 are penetrated by holding means (not shown), in particular screws, in order to fix the bracket 3 to the body of a vehicle (not shown).

The bent sheet metal part 6 has two downward-facing legs 8, on each of which a pivot bearing 9 is supported. A pipe section 10 is pivotably mounted on these pivot bearings 9 about an axis 11, which is aligned approximately horizontally and perpendicular to the longitudinal extension of the coupling shaft 2. The pipe section 10 is penetrated by the coupling shaft 2, which is held therein so that it can be moved longitudinally and rotated.

To lock the coupling shaft 2 to the holder 3, the coupling shaft 2 has a through hole 12 through which a locking pin 13 passes. This locking pin 13 is shown in section in Figure 1 for better visibility of its cross section. The locking pin 13 passes through holes 14 in the holder 3, the inner diameter D of which is adapted to the outer diameter of the locking pin 13. The holes 14 in the holder 3 are accessible from the outside through channels 15, the width B of which is smaller than the diameter D of the hole 14. The locking pin 13 has a circular cross-section in the area of the hole 14 in the holder 3, the height H of which is slightly smaller than the width B of the channel 15.

In the locking position of the locking pin 13 shown in Figure 1, it is rotated so that its flat surface is positioned essentially vertically and faces away from the channel 15, so that the locking pin 13 is fixed in the bore 14 of the holder 3. By rotating the locking pin 13, it can be brought into a release position in which it can be pushed out of the channel 15.

so that the coupling shaft 2 is held in the pipe section 10 so that it can pivot freely and be moved longitudinally. In order to be able to rotate the locking pin 13, a gripping part 16 in the form of a rotary knob, which is only indicated by dashed lines, is provided.

In the coupling position shown in Figure 1, the coupling member 5 projects beyond the rear of the vehicle (not shown), with the rear end 4 of the coupling shaft 2 pointing upwards. If the trailer coupling 1 is not required, the locking of the coupling shaft 2 is released by turning the gripping part 6 so that the locking pin 13 can be pulled out through the channel 15 of the holder 3. The coupling shaft 2 can then be freely pivoted about the axis 11 in the pivot bearing 9 and rotated about its own longitudinal axis. The coupling shaft 2 is now pivoted about the pivot axis 11 by approximately 180° and at the same time rotated about its own longitudinal axis by approximately 90°. The end 4 of the coupling shaft 2 thus points forwards and to the side so that the coupling shaft with the coupling member 5 can be stored under the vehicle in a space-saving manner. In particular, the coupling member 5 does not reduce the ground clearance of the vehicle in any way. A particular advantage is that the coupling shaft 2 does not have to be separated from the holder 3 and stored separately, but is always connected to the holder 3 and supported by it.

In order to store the coupling shaft 2 in the storage position (not shown) with the coupling shaft facing forward,

••i* ♦ · “it”

-12-

In order to hold the coupling member 5 securely, a further locking device 17 is provided, which is formed by a spring-held pin 18 and a gripping part 19. The pin 18 is pre-tensioned against the coupling shaft 2 by a spring (not shown) and penetrates into a hole 20 in the coupling shaft 2 in the storage position (not shown). This ensures that the coupling shaft 2 is held sufficiently securely in the storage position, and in this position no pushing or pulling forces need to be supported by trailers.

In order to be able to support high support loads in the coupling position of the coupling shaft 2, a roller 21 is freely rotatable in the front of the holder 3, which presses against the coupling shaft 2 from above. This freely rotatable roller 21 ensures sufficiently secure support of the support loads, while still making it easier to insert the coupling shaft 2 into the pipe section 10.

Figure 2 shows a side view of the trailer coupling 1 according to Figure 1, wherein the same reference numerals designate the same parts. In addition to the locking pin 13 in its locking position, this is also indicated in dashed lines in its release position, from which it can be seen in particular that the height H of the locking pin cross section is slightly smaller than the width B of the channel 15. The locking pin 13 can thus be easily pushed into or out of the channel 15 in the release position shown in dashed lines.

i .-i» *# fi H

-13-

A signaling device 22 is provided on the outside of the bracket 3 in the area of the channel 15, which emits an electrical signal when the locking pin 13 is engaged and locked in the bore 14. This signaling device 22 can be used in particular to switch on a warning light visible from the driver's seat in the event of a failure to lock the locking pin 13.

Figure 3 shows a sectional view of the trailer coupling 1 according to Figure 3 along the section line III-III in the storage position of the coupling shaft 2. From this view it can be seen in particular that the locking pin 13 has a section 23 with a cylindrical cross-section and is pressed by a spring 24 into a position in which the cylindrical section 23 penetrates the bore 14. This provides additional protection for the coupling shaft 2 against accidental release from the pipe section 10, since the locking pin 13 locks the coupling shaft 2 regardless of its rotational position. To release the coupling shaft 2, the locking pin 13 must first be moved axially with the aid of the gripping part 16 until sections 25 which are circular in cross-section engage with the bores 14 of the holder 3. The locking pin 13 is then rotated with the aid of the gripping part 16 until the section 25 can be pulled out of the channel 15. In the middle area, the locking pin 13 has a cylindrical section 26 in order to enable the coupling shaft 2 to be gripped over as large an area as possible.

-14-

To lock the coupling shaft 2 in the storage position shown in Figure 3, the conical pin 18 of the locking device 17 is loaded against the coupling shaft 2 by means of a spring 27. The pin 18 penetrates into the bore 20 of the coupling shaft 2 so that it is locked.

In order to achieve the greatest possible rigidity of the coupling shaft 2 while keeping the weight as low as possible, the coupling shaft 2 consists of a tube 30 into which an I-beam 31 is inserted, as shown in the cross-sectional view in Figure 4. The tube 30 has a circular cross-section, and in principle no mutual fastening is required between the tube 30 and the I-beam 31. Rather, it is sufficient to insert the I-beam loosely into the tube 30, after which both parts are bent together into the shape shown in Figure 1. Alternatively, however, it is also conceivable to connect the I-beam 31 to the tube 30 at least at the ends, which could be done by welding, for example. The vertically aligned I-beam results in considerable stiffening of the coupling shaft 2 in the vertical direction, so that the coupling shaft 2 can transfer relatively high support loads with a low dead weight.

Figure 5 shows an alternative embodiment of the coupling shaft 2. In contrast to the embodiment according to Figure 4, this has a T-beam 32 in the tube 30, the middle leg 33 of which is aligned vertically. As a result of the cross leg 34, an additional

&iacgr; HS* ». &bgr;« ·»

-15-

Stiffening in the vertical direction, whereby it is fundamentally irrelevant whether the transverse leg 34 is provided above or below the central leg 33.

Figure 6 shows a further alternative embodiment of the coupling shaft 2, wherein an H-beam 35 is inserted into the tube 30. This H-beam 35 also has a vertical center leg 33. The two cross legs 34 ensure a considerable stiffening of the coupling shaft 2 in the vertical direction.

Finally, Figure 7 shows a further alternative embodiment of the coupling shaft 2, in which an I-beam 31 is inserted into an elliptical tube 36. The elliptical tube 36 has a vertically aligned main axis 37, so that it has a larger vertical than horizontal extension. This also results in additional stiffening of the coupling shaft 2 in the vertical direction. Of course, it is also conceivable to insert a T-beam 32 or an H-beam 35 into the elliptical tube 36 in order to achieve further stiffening.

-16-

List of reference symbols

1 trailer hitch 26 cylindrical Ab 2 Coupling shaft cut of the locking
Pen 3 bracket 27 Feather 4 rear end of the on Coupling shaft YE Conr 5 Coupling link 31 I-beam 6 Sheet metal bent part 32 T-beam 7 drilling 33 Middle thigh 8th leg 34 Cross leg 9 Pivot bearing 35 H-beam 10 Pipe section 36 elliptical tube 11 Swivel axis 37 Main axis 12 Bore of the coupling B Width of the channel lungsschaft D Drilling diameter 13 Locking pin H Height of the locking 14 Hole of the bracket pin cross section 15 channel 16 Gripping part 17 Locking device 18 Pen 19 Gripping part 20 Bore of the coupling lungsschaft 21 role 22 Reporting device 23 cylindrical Ab cut of the locking pen 24 Feather 25 circular segment-

ger section of the locking pin

• «

·

·

Claims (13)

1. Trailer coupling for a vehicle, in particular for a passenger car, the trailer coupling (1) having an adjustable coupling shaft (2) which, in a coupling position, is aligned horizontally essentially in the longitudinal direction of the vehicle and is bent upwards at the rear end (4) provided with a coupling member (5), the coupling shaft (2) being supported in a holder (3) which is firmly connected to the vehicle so that it can rotate about its longitudinal axis and can be locked, characterized in that the coupling shaft (2) is supported on the holder (3) so that it can pivot between the coupling position and a storage position in which the coupling member (5) is directed forwards and to the side. 2. Trailer coupling according to claim 1, characterized in that the coupling shaft (2) is supported on the holder (3) so as to be pivotable about an approximately horizontal axis (11). 3. Trailer coupling according to claim 1 or 2, characterized in that the coupling shaft (2) is held in a pipe piece (10) which is pivotally supported on the holder (3) in pivot bearings (9). 4. Trailer coupling according to at least one of claims 1 to 3 or according to the preamble of claim 1, characterized in that the coupling shaft (2) in the coupling position is supported in the region of its front end on the top side on a roller (21) of the holder (3) which is freely rotatable about an axis aligned substantially horizontally and perpendicular to the longitudinal axis of the coupling shaft (2). 5. Trailer coupling according to at least one of claims 1 to 4 or according to the preamble of claim 1, characterized in that for locking the coupling shaft (2) on the holder (3) a bore (14) is provided at the rear, which in the coupling position is aligned with a bore of the coupling shaft (2) and is accessible from the outside via a channel (15) with a smaller width (B) than the bore diameter (D), wherein the mutually aligned bores (14) are penetrated by a locking pin (13) which in cross-section at least in part has the shape of a circular section, the height (H) of which is less than or equal to the channel width (B) and which is held rotatably between a locking position locking the coupling shaft (2) and a release position releasing it. 6. Trailer coupling according to claim 5, characterized in that the locking pin (13) has in the region of its end a section (23) with a circular cross-section, the diameter of which corresponds approximately to the bore diameter (D) of the holder (3), the locking pin (13) being pressed by a spring (24) into a position in which this section (23) penetrates into the bore (14) of the holder (3). 7. Trailer coupling according to claim 6 or 7, characterized in that the locking pin (13) is connected to a gripping part (16). 8. Trailer coupling according to at least one of claims 5 to 7, characterized in that the locking pin (13) is assigned a signaling device (22) which emits a signal in the locking position of the locking pin (13). 9. Trailer coupling according to at least one of claims 1 to 8, characterized in that a locking device (17) for the coupling shaft (2) in the storage position is provided on the front of the holder (3). 10. Trailer coupling according to claim 9, characterized in that the locking device (17) for the coupling shaft (2) in the storage position is formed by a spring-loaded pin (18) which passes through a bore in the holder (3) and, in a locking position, penetrates into a bore (20) in the coupling shaft (2). 11. Trailer coupling according to claim 10, characterized in that the front bore of the holder (3) is offset from its rear bore (14) - viewed in the longitudinal extension of the coupling shaft - by approximately 90°. 12. Trailer coupling according to at least one of claims 1 to 11 or according to the preamble of claim 1, characterized in that the coupling shaft (2) is formed by a tube (30, 36) into which an I- (31), T- (32) or H-beam (35) with a vertical central leg (33) is inserted. 13. Trailer coupling according to claim 12, characterized in that the tube (36) has an elliptical cross-section with a vertical main axis (37).