RU77826U1 - HITCH ASSEMBLY FOR LIGHT WHEELED VEHICLES - Google Patents

Abstract

The invention relates to non-rail passenger vehicles and, in particular, to means for connecting vehicles in order to increase the operational parameters of a bicycle and other light wheeled vehicles used for individual and group trips. The hitch assembly includes at least one hitch head, including a locking mechanism with a self-locking screw screw running screw connected to a lever, and at least one connecting rod. It is characterized in that the locking mechanism is made in the form of pivotally connected movable and fixed jaws. The free end of the fixed jaw is made of rectangular or tubular shape and is rigidly or pivotally connected to a rod having a rectangular or circular cross section, and the working parts of the jaws are cylindrical or ribbed in shape, designed to be tight with an interference fit with the male assembly. The device is characterized by simplicity of design. 10 s.p. f-ly, 18 ill.

Description

The utility model relates to non-rail passenger vehicles, in particular to light wheeled vehicles, in particular bicycles, mopeds, motorcycles, etc. The proposed design can be used as a means of connecting vehicles in order to increase operational parameters for individual and group trips in the city and on intercity routes. Known hitch assemblies for connecting to a towing device (Hitch), for example, a towbar type - a ball type device designed for towing caravans and car trailers by a vehicle (see OST 37.001.096-84 "Ball-type towing devices for towing caravans and car trailers ”, paragraph 1 a and GOST 28.248-89).

This hitch assembly contains a hitch head in the form of a cup covering a ball of a towing device (towing device), a locking mechanism with a lever and a drawbar (rod) attached to the trailer. The joint provides many degrees of freedom of the trailer when moving. The disadvantages of this device include the complexity of the design and the inability to tow bicycles with its help and parallel connection between them for joint driving.

Known coupling unit used to attach trailers to a motorcycle (US patent 6312003 B1, CL B62D 63/06, publ. 12/28/1999). The disadvantages of this device include the impossibility of connecting bicycles and other means with wheels arranged in series along the axial line of the vehicle, and connecting them together in parallel.

Known hitch assembly in the form of a fork, used to attach a trailer to the axis of the rear wheel of a bicycle (US patent 6481735 B1, class B62K 27/00, publ. 05.19.2000). The disadvantage of this connection is the design complexity and the impossibility with its help of a parallel connection of wheeled vehicles.

The closest coupling used in the “Bicycle tandem with a detachable and folding rear bicycle

part "(US patent 5836600, CL BK 27/00, publ. 11/17/1998). The disadvantages of the prototype include the complexity of the design of the connecting part of the device, the inability to connect with it other wheeled vehicles and a powerful towing vehicle and, as a consequence, the inability to further increase the operational parameters of a bicycle vehicle.

The purpose of the utility model is to eliminate the above disadvantages of ensuring the movement of several riders and the joint compact movement of bicycles, scooters, trolleys with passengers and luggage, wheelchairs and prams and other light wheeled vehicles, as well as creating the conditions for connecting them to a motor towing vehicle.

The technical result of this utility model is to simplify the design and coupling process.

The technical result is achieved due to the fact that the hitch assembly contains at least one hitch head, including a locking mechanism with a self-braking screw running screw connected to a lever, and at least one connecting rod. It is characterized in that the locking mechanism is made in the form of pivotally connected movable and fixed jaws. The free end of the fixed jaw is made of rectangular or tubular shape and is rigidly or pivotally connected to a rod having a rectangular or circular cross section, and the working parts of the jaws are cylindrical or ribbed in shape, designed to be tight with an interference fit with the male assembly.

In a specific embodiment, the working parts of the jaws are provided with pads of various configurations.

In a specific embodiment, a shock absorber is mounted between the hitch head and the link or the link.

In a specific embodiment, the assembly is provided with rods with mounts for mounting on the steering wheel of a light wheeled vehicle.

In a particular embodiment, at least two coupling heads are connected by one rod.

In a particular embodiment, the fixed jaw comprises a sleeve at the end to enable the rod to rotate around its longitudinal axis of the rod to fix this position.

In a particular embodiment, the at least two coupling heads have a fixed sponge or rod containing, at the end, a transverse sleeve for interconnecting a tubular transverse rod.

In a particular embodiment, the assembly comprises a longitudinal rod for connecting at least two rods.

In a particular embodiment, a shock absorber and / or a stand for the awning are mounted on the longitudinal link.

The connection between the fixed sponge and the rod of rectangular or circular cross section and can be made rigid or articulated with the possibility of rotation in the horizontal plane with the fixation of this position. This design provides the convenience of a compact connection of wheeled vehicles between themselves and a trip with possible turns, ascents and descents on the road.

The working parts of the jaws can have a shape designed to clamp a cylindrical or rectangular rod, and can be equipped with a set of pads (bumps) of various configurations, which ensures greater convenience and reliability of adhesion.

The end of the fixed sponge can have a ring-shaped shape, and the thrust connected to it can have a circular cross section, which makes driving on a road with bumps more convenient.

A shock absorber can be installed between the hitch head and the traction, which facilitates safe emergency braking when driving at high speed.

The hitch assembly kit may include rods with fasteners for mounting on the handlebars of the attached bicycle, allowing the rider to significantly increase the power developed by him due to his standing position, as well as increase the all-round visibility.

The proposed design provides a rigid clamp without the possibility of sliding under impact load.

The invention is illustrated by a description of a specific implementation and the relevant drawings.

Figure 1 shows the hitch head in rigid connection with traction.

Figure 2 shows the hitch head, the axis of the swivel of the jaws of which is located vertically, and the connection of the fixed jaw with the rod is made hinged with the possibility of rotation in the horizontal plane.

Figure 3 shows the serial connection of two coupling heads with a single rod.

Figure 4 shows the connection of the two coupling heads with one thrust at a certain angle to the direction of movement.

Figure 5 shows a variant of the hitch assembly, which allows you to rotate the rod by a certain angle around its axis.

Figure 6 shows the connection (top view) of bicycles and a wheelchair.

7 shows the connection of two tandem bicycles, called "double arrow", allowing to develop high speed.

On Fig shows a tandem bicycle "arrow" with two riders.

Figure 9 shows the parallel connection of two cyclists to a vehicle towing them, carried out by means of coupling units and an automobile trailer hitch.

Figure 10 shows an option for attaching a group of cyclists to a pulling car using long sections pivotally connected.

Figure 11 shows the options for the nodes of the coupling, in which the thrust is made in the form of a pipe and attached to the sectioned traction body of the lifting-transport mechanism (machine). Shown here is a structure where the fixed jaw has an annular shape.

12 shows cyclists attached to a car using additional devices that provide greater safety during emergency braking.

On Fig shows the connection (top view) of a group of cyclists in a structure called "peleton".

On Fig shows a "pellet" (side view), moving at a fairly high speed independently - without a tow.

Fig. 15 shows a bicycle scooter and a lightweight one-wheeled trolley for one passenger attached to the “field”.

On Fig shows a "field", equipped with an awning to protect against sun and rain. An attached trolley with a boot is also shown here.

On Fig shows a "field" (side view of its front part), in which motorcycles are attached to the front link.

On Fig shows the possibility of pivotally mounting traction of rectangular cross section on the section of the traction body.

Detailed description of various design options.

Figure 1 shows the rod 1, designed to be attached to the trailer, and the entire hitch assembly 2. Here, the connection between the thrust and the head of the hitch assembly can be rigid or articulated, which is provided by the presence of a hole 5, which can have a round or rectangular cross-section. The locking mechanism of the hitch head 3 is equipped with a lever 6. At the hitch head can also be applied self-locking clamping devices of tensioning action, with a crank eccentric or lock design. For

providing rigid articulation with the node of the attached vehicle, for example with a bicycle frame, the working parts 7 of the jaws have a shape designed to clamp the rod of a cylindrical or rectangular profile. Sponges can be made movable, as well as have complete set of mouthpieces of the necessary shape. The coupling unit, go only its working parts may have some inclination with respect to the axis of the link 1. At the other end of the rod, an opening may be provided for rigid or articulated connection with other devices (trailer).

Figure 2 shows the coupling assembly 8, in which, unlike the assembly 2, the axis of the hole 5 is perpendicular to the axis of rotation of the jaws 3. The configuration and the end face of the rod 1 (rounding) and the inner surface of the slot in contact with it in the fixed jaw 4 determine the possibility and angle the rotation of the rod 1 around the axis of the hole 5. The design of the lever 6 shown here can be equipped with a ratchet mechanism that facilitates the user to work with the coupling unit. A rigid connection of the coupling unit with the attached object in devices 2 and 8 is provided by the coupling head 3.

Figure 3 shows the connection of bicycles one after another ("chain"), where both nodes of the coupling 8 have a common link 1. Connecting parts 7 of the jaws (heads) 3 are made slightly inclined in accordance with the inclination of the front tube of the frame. rear bicycle and the inclination of the appendage of the tube under the front saddle. To protect against damage to the coating of attached products under the sponges can be installed bibs. The connection of the end of the rod 1 with the fixed sponge 4 of the coupling head is made by means of a hinge with a bolt or captive finger (not shown in the drawing) inserted into the hole 5, the axis of which is located in a horizontal plane. This provides the possibility of mutual vertical movement of bicycles when riding on rough roads (pits, mounds) while maintaining a reliable joint using the coupling head. The advantage of such a connection is also that the rear bike, rigidly attached to the steering column, is deprived of the possibility of deviating from a vertical position and independently turning to the side, regardless of the position of its steering wheel. Therefore, the rear bike is shown riding in slave (non-guide) mode, as its steering wheel with front wheel fork is rotated 180 degrees. This allows the second cyclist not even to use the wheel. This position with the “deployed” steering wheel is desirable, but not necessary. Otherwise, the second cyclist must hold the wheel against spontaneous turning. In addition, it also shows the ability for the rear cyclist to ride standing, using the steering wheel mounted

fastenings 9 with support rods 10, which make it possible to use the most powerful muscle groups of the body and the strength of the rider's weight while standing. This possibility arises due to the fact that the stability of this rigid tandem system is determined by the front bike. On straight sections of the track and on lifts with rods 10 (if they are installed in advance), a front cyclist can also use it. The mount 9 is equipped with a wing clamp 11, which allows you to install the rod 10 in a vertical position and so fix it. In conjunction

"Wake" can ride a large number of cyclists. It is possible that in this case it is advisable to make one or several connections by means of the coupling unit 2 or use the cardan joint between the rod 1 and the fixed jaw 4 of the vise in order to enable the rotation of a long chain of cyclists. In the case when you know in advance what you need to take a partner or a passenger on the way, use the coupling on the back to hook another bicycle or passenger carriage (see Fig. 15).

Figure 4 shows (top view) the connection of cyclists (riders themselves are not shown), in which the connection between the bikes is made at a certain angle, which ensures greater stability of their vertical position and allows both riders, leaning on the rods 10, to ride standing, removing all the benefits arising from this. ' Such a construction can be called "spark". Here, the coupling unit 12 is used (see Figs. 5 and 6), which allows connecting with the link 1 the parts of the attached bicycles (or other wheeled vehicles) located in different planes. Further, other cyclists can join this stable system even at stops.

Figure 5 shows a part of the hitch assembly 12, which allows you to rotate the rod 1 by a certain angle around its axis and rigidly fix this position. Here, the fixed jaw 4 terminates in a nozzle 13 into which a cylinder 14 is inserted. In the nozzle 13 there are opposing slots 15, and in the cylinder there is a diametrical hole 16 through which a latch (for example, a bolt with a nut) is inserted for their mutual rotation about a common axis. For reliable fixing under the nut and bolt head (these details are not shown in the drawing) covering shoes 13 can be installed. This is one of the options for the assembly 12. Instead of the assembly 12, coupling units 2 or 8 can be used, in which the working parts 7 of the jaws are prefabricated by turning at some angle around the axis of the link 1.

Figure 6 shows (top view) the connection through the nodes of the coupling of three bicycles and a wheelchair 17, when two bicycles are connected to the first bicycle at once in parallel. This design ("cavalcade") is even more stable than on

Figure 4, but it occupies a slightly larger width of the lane on the road. Here, cyclists can also ride standing with the support rods 10 on the steering wheel, and the number of attached bikes and / or wheelchairs or trolleys, tricycles or trolleys with luggage can be quite large. The carriage 17 is attached to the bicycle by means of a traction 1. The front two small wheels are lifted while traction and do not touch the road surface. The attachment of one of the bicycles can be made not only to the appendage of the tube of the saddle of the front bicycle, as in Figure 3, but, for example, to the top of the rear wheel forks.

Figure 7 shows the connection of two tandems "arrow", which can develop a fairly high speed. Such a connection can be called - "double arrow". Here, the tandem bicycle allows the rider standing behind to work with sticks 18 as a skier and use powerful muscle groups and the strength of his weight. The sticks are installed in the guides 19 (see Fig. 8 for details), and the rollers at their ends are equipped with a one-way rotation mechanism. Long distance riders can change places. The connection between the bicycles is carried out by means of the coupling units 8 with a total thrust of 1, and in order to reduce dynamic loads during sharp braking, a shock absorber 21 having a sufficiently long stroke can be installed between the thrust and the vice. A seated rider may be equipped with a seat belt 22 (see Figure 9). The cyclists shown in series can be continued.

Triple Arrow carries six riders. Its cruising speed is about 50 km / h. In this case, it is desirable that the protective helmet worn on the cyclist’s head has a transparent visor (visor).

On Fig shows the tandem "arrow". It can be seen here that the safety arch 20 covering the lower back of the rider is mounted on a belt 23 fixed under the saddle of the bicycle. The belt is equipped with a spring (it is not shown), providing its stretching. The guides 19 of the sticks 18 are mounted at the ends of the curved beam 24, mounted in the sleeve 25 on a special shank. This sleeve may have an antler or other clamp, fixing the angle of rotation of the crossbar 24, which provides the convenience (if necessary) of fixing the sticks in an inoperative vertical position. Holders 27 with pedals for the legs of a standing rider are mounted on the branches of the fork on the sides of the rear wheel.

Figure 9 shows the parallel connection of two cyclists through the nodes of the coupling 8 with inclined rods 1 to the rear towing device 28 mounted on the vehicle, for example, a hitch type. The left cyclist in the drawing is not

it is visible, it is closed to the right, only the second link and the second (upper) coupling unit are partially visible 8. It is better if instead of or together with the end ball, an end rod 29 is installed on the TSU 28, which will be high enough to connect two bicycles to it at once will have a thread on top for tightening with a nut to increase the rigidity and reliability of this connection. The rigid articulation of the hitch head through the node 8 and its long traction 1 will not allow the right cyclist to approach the sidewalk with the right turn of the car, which will allow him to avoid hitting the right edge. It is also advisable here that the connection of the shock absorber 21 with the rod be made articulated with a vertical axis of rotation (a cardan joint can be used) or use rods that can work on bending when turning the car. Cyclists can be equipped with car seat belts secured under the saddle of the bicycle 22. Other bikes, wheelchairs and prams, and freight and passenger carts can be attached to the bikes at the rear via hitching devices. As a pulling motor means, not only a car can be used, but also a scooter or a motorcycle. The driver’s light signals, which are output from the rear of the pulling means through the connector on the vehicle’s vehicle, can be relayed on the rear bike using a cable. Not only bicycles can be connected, but also other light wheeled vehicles.

Figure 10 shows (top view) the connection to the car of a group of cyclists (riders not shown) and a chain of three pivotally connected sections 30. Connection to the car is carried out by means of a tow bar with an end shaft 29 and inclined rods connected to it 1. Sections 30 are below the steering wheel of bicycles, which are attached here through shock absorbers 21 (this is not necessary). The sections 30 are hinged by means of bolts 31. The sleeve 32 mounted on the sections serves to install the luggage trolley in it from below and / or to maintain the level of sections 30 above the road convenient for cyclists. On top of the sleeves 32 can be installed racks (see Fig.16), on which can be mounted an awning that protects riders from the sun and rain. The number of sections connected one after another 30 (and, therefore, cyclists) is determined as necessary. At the rear of the last section is a repeater of turn and brake light signals transmitted from the driver through the connector on the vehicle. Section 30 can also be joined by wheelchairs and prams, and various trolleys, as well as scooters or motorcycles with the engines turned off.

11 schematically shows a series of articulation of several sections 30, carried out using a bolt inserted into the holes 33. Here also shows the sleeve 32 mounted on the section. In addition, a double-sided tubular rod 34 is mounted on the section, fixed by means of a bolt inserted into

hole 35. The rod 34 can be mounted on any section 30. It is designed to connect cyclists (or other light vehicles) using the hitch head 3, the fixed jaw 4 of which has an annular end, for example, sleeve 36. In this compact modular connection, which one of the embodiments of the present invention, the function of the rod 1 is performed by the rod 34. Such a hitch assembly 37 may have an elongated fixed jaw 4, which will allow arranging the attached bicycles (scooters, motorcycles) in a checkerboard order so as not to occupy a wide lane. This compact design, called the “peloton”, can be moved on the road either independently or towed by motor vehicles. In the latter case, the engines of the motor means connected behind the towing vehicle must be switched off. With independent movement of the attached motor means, only one or two front engines should work.

12 shows cyclists joining the rods 34 through spring shock absorbers 38 and coupling units 2. In addition, the rods themselves have their own group (for all cyclists attached to the rod) spring shock absorber 39. The front inclined link 1 is connected to the towing device 28 on a car. Instead of the front thrust, a strong and long cable can be used in the “field”, but the front cyclist must ride in the “leading” position. Trolley 40, which is essentially the front fork of a conventional bicycle, is designed to maintain a comfortable level of sections 30 above the road. The trunk can be installed on it.

In Fig.13 shows a cycling group - "peleton" (the riders themselves are not shown), attached to a passenger car. He can move at high speed, overcoming long distances and any climbs on the road. A group shock absorber 39 is also used here. The number of attached cyclists can be quite large. Such an automobile option can be used as a fixed-route bicycle taxi inside the city and on intercity routes. On the road, cyclists can easily join or disconnect at stops. Taxi can transport in the car and in the trolleys 41 (see Fig. 15) also joined passengers-pedestrians.

On Fig shows the "field", moving independently (without a tow). It is seen here that when using the group spring shock absorber 39, the rod 34 is not fixed by a bolt (in the hole 35) on the section 30. The front end of the shock absorber 39 is fixed with a stud 42 on the section, and the rod 34 can move forward when braking. At the front end of the first section, on a “field”, a spring sheet 43 is installed, which acts as a front buffer. These and other devices provide comfort and safety when driving. Other cyclists or trolleys, including passenger ones, can join the free hitch nodes.

On Fig, along with a conventional bicycle shows the connection to the "field" and a bicycle scooter 44, equipped with a folding saddle for standing up and one-way rotation mechanisms of the drive gear of the chain drive. These gears are mounted between this gear and the pedal levers for cycling. Tuklipsy are installed on the pedals themselves. With the independent movement of the bicycle scooter, you can ride it either as on a bicycle while sitting or standing, or as on a scooter - standing, pushing off with one foot. In the latter case, the right pedal is retracted (as shown in the drawing). This option is convenient in case of independent driving on the sidewalk. The drawing also shows a one-wheeled trolley 41, attached to the bar 34, for one passenger. It is desirable that the routes of fixed-route bicycle taxis be equipped with rental bicycles and passenger single and multi-seat trolleys. The regularity of movement (like a bus or tram) of such taxis (small, towed by a motorcycle, or large by car) will provide users not only with public transport, but also with a large number of everyday motorists due to the fact that the bicycle delivers its rider directly “from door to door” "While reducing travel time. In addition, everyday use will provide both serious financial benefits, and getting rid of numerous automobile troubles. Do not forget about the great environmental importance of a bicycle as a means of transport.

On Fig shows the part of the "field", over which is installed an awning 45, which protects riders from the sun and rain. Awning racks 46 installed in the bushings 32 are supported. For the same purpose and to protect from wind, a transparent canopy (sidewalls) can be suspended from the awning. The drawing shows trolleys 40, on one of which a luggage carrier 47 is mounted. This trolley is attached directly to the rod 34 using the hitch assembly 37. If necessary, raise the level of sections 30 if necessary for convenience, high washers 48 can be installed at their junction, such as this takes place above the rear trolley 40. The drawing also shows the option of fastening the belt

23 on a tandem bike. The belt is fastened to the saddle by means of a spring strut 49.

On Fig shows the front of the “field”, in which motorcycles are attached to the front rod 34 (their riders are not shown). One or two motorcycles located directly near section 30, in this case, perform the function of a towing vehicle, i.e. their engines are operational. In the latter case (when there are two towers), some control synchronization should be provided between them. In addition, it should be borne in mind that the leading vehicles in a self-propelled "field" must have sufficient mass to ensure good adhesion of their wheels to the road surface.

In Fig. 18, the thrust function is performed by a thrust of rectangular cross section 1. At the end of each thrust there is a sleeve worn on a shaft 50 located between the uprights 51 mounted on the section 30. One or both of the uprights are movable. Such a hinged fastening of the rod 1 on the section is necessary when the “pellet” moves along a narrow road or on rough terrain, when there is a ditch or pit at the edge of the road. A swivel mount protects the structure from distortion and overvoltage in the event of a “freeze” on the link 1 of the vehicle attached to it in the cell.

It should be noted that bicycle transport towed by a motor vehicle is advisable if high speed is necessary, as well as on long routes and on steep climbs. Motorized towing can also be justified in cases where members of the same family or guests do not fit in the same car. In all other cases, it is more useful not to resort to a motor tug. It can also be noted that any clutch vise assembly, due to its rigidity and high stability, allows all small trailers to be made unicycle.

The technical and economic efficiency of the invention indicates that the considered rigid vise hitch assemblies articulate the mobility device into a single, stable, modular design that has sufficient flexibility in the vertical and horizontal plane. This gives her the ability to move freely on various roads with turns and climbs and at a fairly high speed. At the same time, the design of the coupling units does not allow any of the articulated devices to deviate from a vertical position (perpendicular to the road surface) during movement, which ensures stability in the way of both the entire structure and its individual components, even having wheels located on one line (bicycle, scooter, one-passenger or luggage

cart, etc.). This quality of the coupling units allows for the implementation of simple and reliable updated bicycle transport, which is efficient in terms of operational and environmental parameters. An electric bicycle can also be widely used here, which, having disconnected from the general caravan on the intercity highway, can independently move further inside the big city without any special effort on the part of the rider. Even more useful is riding further on the tandem arrow. Rigid hitch assemblies and other devices and modular designs discussed above (sections, pull rods, horizontal shock absorbers, “peleton”) are also applicable to some other relatively light self-propelled vehicles (mopeds, scooters, motorcycles, battery-powered carts, etc.) . Their compact combination on long routes with a motorized towing vehicle (a powerful tractor vehicle) will allow you not to use your own engines. The objectives pursued in this case are fuel economy, reduction of gas contamination of the environment and greater compactness on the road due to the smaller occupied bandwidth and the small distance between the devices even at high speeds. Such caravans, including purely bicycle ones, will contribute, in addition to fuel economy, to the preservation of the environment and the unloading of transport routes, and their long-distance routes will have a timetable similar to those available on rail and bus transport.

Claims (11)

1. The hitch assembly for light wheeled vehicles, comprising at least one hitch head, comprising a locking mechanism with a self-locking screw screw connected to a lever, and at least one connecting rod, characterized in that the locking mechanism is made in the form of pivotally connected movable and fixed jaws, the free end of the fixed jaw being rectangular or tubular and rigidly or pivotally connected to a rod having a rectangular or circular cross section, and the working parts of the lips to have a cylindrical shape or a ridge, intended for coupling with the rigid interference fit with the male assembly, 2. The hitch assembly according to claim 1, characterized in that the working parts of the jaws are provided with plates of various configurations. 3. The hitch assembly according to claim 1, characterized in that a shock absorber is installed between the hitch head and the link or the link. 4. The hitch assembly according to claim 1, characterized in that it is provided with rods with mounts for mounting on the steering wheel of a light wheeled vehicle. 5. The coupling unit according to claim 1, characterized in that at least two coupling heads are connected by one rod. 6. The hitch assembly according to claim 1, characterized in that the fixed jaw contains a sleeve at the end to enable rotation of the rod around its longitudinal axis of the rod with the fixation of this position. 7. The hitch assembly according to claim 1, characterized in that, at least for the two coupling heads, the fixed sponge or rod contains at the end a transverse sleeve for connecting a tubular transverse rod to each other. 8. The hitch assembly according to claim 1, characterized in that it comprises a longitudinal rod for connecting at least two rods. 9. The hitch assembly of claim 8, characterized in that a shock absorber and / or rack for the awning are mounted on the longitudinal link. 10. The hitch assembly according to claim 1, characterized in that at the end of the fixed jaw there is a nozzle into which a cylinder connected to the rod is inserted, while in the nozzle there are opposite slots, and in the cylinder there is a diametrical hole for installing the position lock. 11. The hitch assembly according to claims 7 and 8, characterized in that at least two transverse rods are provided at the ends with transverse bushings mounted on a common axis mounted on a longitudinal rod.