WO2008017941A2

WO2008017941A2 - Trailer with inertia braking system

Info

Publication number: WO2008017941A2
Application number: PCT/IB2007/002301
Authority: WO
Inventors: Christian Steger-Vonmetz
Original assignee: Christian Steger-Vonmetz
Priority date: 2006-08-08
Filing date: 2007-08-08
Publication date: 2008-02-14
Also published as: WO2008017941A3; AT504023A1

Abstract

The present invention relates to a trailer, in particular a bicycle trailer, with a chassis composed of light-metal tubes, on which one wheel is arranged on opposite sides respectively. A drawbar (13) is arranged on the chassis (15), the chassis (15) and drawbar (13) being displaceable relative to one another in the longitudinal direction. Brake shoes (23) are arranged on the drawbar (13) or on a lever (33) connected to the drawbar. When the trailer overruns a tow car connected thereto, said brake shoes (23) act on the wheels from behind - seen in the direction of travel - and brake the wheels through friction. The arrangement of the brake lever is preferably such that efficiency is increased by a self-energizing effect. The chassis (15) and the drawbar (13) are preferably biased by spring means in a starting position in which the brake shoes are spaced apart from the wheels.

Description

Trailer with casserole brake

Field of the invention

The present invention relates to a trailer according to the preamble of claim 1.

State of the art

In recent years, more and more light metal trailers have come into fashion for the transport of children. Such trailers must have a low dead weight, but still have the necessary stability. In operation, the cyclist must be able to decelerate both its own weight and the weight of the trailer. The trailer results in an extended braking distance. Particular dangers threaten when driving down or when an abrupt braking maneuver is required. There are therefore trailer brakes have already been proposed, which are coupled for example with the bicycle brake. Although this solution works in principle, the braking force is independent of the load and thus either too strong (wheel blocked) or too weak. Also, a coupling between the trailer and the bike must be provided. The aim is a braking system in which the braking force is automatically metered in dependence on the accumulation force.

DE 19636832 discloses a trailer for single-track vehicles, which with a

Casserole brake is equipped. It can be used in the trailer known wheel brakes, as they occur in bicycles. The brake drive for the wheel brakes is provided either between the drawbar and the bicycle trailer or between the trailer hitch and the drawbar. The brake drive consists of a filled with brake fluid brake cylinder and a guided therein brake piston, which can displace the brake fluid. The drawbar relative to the trailer is linearly displaceable or pivotable about a pivot point on the trailer. According to a first embodiment of the brake cylinder are frontally connected to the trailer and the brake piston with the drawbar. When braking the towing vehicle, there is a relative displacement of drawbar and trailer (accumulation of the

Trailer) and the brake drive is operated. According to a second embodiment of the brake drive between the clutch-side end of the drawbar and the clutch is interposed.

A disadvantage of the overrun brake described is that this relatively complex and thus is expensive to manufacture, requires a precise adjustment and the brakes are usually a hindrance when installing and removing the wheels.

The Swiss patent CH235183 discloses a backup brake for trailers, are connected to the drawbar and chassis via a parallelogram mechanism to which a brake pad is attached. During the displacement of the parallelogram by the overrun force, the brake pad presses on the tire of the trailer; the trailer is thereby braked. In two different variants, the brake pad is attached to the drawbar in the first case and in the second case to the connecting piece between the chassis and drawbar.

In the described operation of the brake by pressing a brake body on the tire against the direction of travel of the trailer, the horizontal component of the contact force of the brake body on the tire can not be greater than the casserole force of the trailer. A disadvantage of the overrun brake described is that the

Braking effect so that essentially depends on the friction coefficient between the brake body and tires and is very limited in size, that is, the efficiency can only be very low.

DE-A-19636832 discloses a trailer with overrun brake, although with a higher efficiency can be achieved, however, which is relatively complex and therefore expensive to manufacture, requires a precise adjustment and the brakes in the installation and removal of the Wheels are a hindrance.

Object of the invention

Based on this prior art, the object of the invention is to provide an improved trailer brake. This trailer brake should work reliably and automatically. Another goal is to propose a structurally simple, maintenance-free and easy-to-use braking device. Another goal is to propose a brake with a high braking effect.

DESCRIPTION According to the invention, the object is achieved in a trailer according to the preamble of claim 1, characterized in that the braking device comprises at least one brake shoe, which is arranged at a short distance to the wheels on the drawbar or the articulated rocker or lever connecting the drawbar and the chassis so that when launched the trailer acting on the brake shoe force component acts substantially in the direction of travel. The erf indungsgemäße arrangement of the brake shoe has the advantage that the braking force is enhanced by the thrust, because both forces - shear and friction - act in the direction of travel. For the generation of an efficient braking effect is therefore important that the brake shoe as seen in the direction of travel attacks from the rear of the wheel. In contrast to erf indungsgemässen arrangement the trailer according to the initially discussed CH-A-235183 counteracts the contact force of the brake shoe of the thrust, so that the braking effect is greatly limited. The inventive trailer has the further advantage that it is structurally simple and therefore inexpensive to produce. The relative displacement of drawbar and chassis can be done by a tilting movement (rotation) or by a parallel displacement, with a tilting movement is preferred because it is easier to implement. The proposed type of overrun brake allows an effective braking of the trailer in the event of the trailer hitting the towing vehicle. The brake device may be directly or indirectly mechanically connected to the movable chassis to use the relative movement of the chassis to actuate the brake device. In principle, it is conceivable to provide only one brake on one side of the trailer.

Advantageously, the brake shoe engages radially on the wheel. This embodiment has the advantage that the brake shoe does not hinder a change of the wheel. In addition, there is less risk that the brakes dirty when the brake shoe radially on the inside of the wheel, respectively. the rim attacks.

A preferred embodiment provides that the pivot point of the brake lever is arranged so that the frictional force acting between the wheel and the brake shoe increases the contact pressure (spreading of the chassis and the drawbar is favored). This can be achieved, for example, by an eccentric arrangement of the brake lever with respect to the pivot point of the wheel. In such an arrangement of the brake lever, the braking force amplifies itself or is weakened during reversing. The brake lever is thus arranged so that a force component is generated by the frictional force, which in turn further increases the contact pressure. This has the advantage that a good efficiency can be achieved in a compact design. The danger that usually arises with self-reinforcing brakes is that the brake is locked. This danger does not exist in the proposed overrun brake. If the trailer decelerates more than the towing vehicle, the brake is automatically relieved.

An expedient embodiment provides that the brake lever is articulated to the chassis. In this case, one arm of the brake lever can be connected to the drawbar via a cable, and the brake shoe can be provided on the other arm of the brake lever. By such a construction, the contact pressure of the brake shoe can be greater by the achievable leverage than in a construction where the trailer runs on a fixed brake shoe.

According to a preferred embodiment, a brake shoe carrier resp. Brake lever provided, which is hinged to the drawbar and the chassis. This has the advantage that can be dispensed with a cable or additional lever.

A preferred embodiment provides that the brake shoe support defines a Y- or V-shaped lever, which is hingedly connected with the legs on the one hand with the drawbar and on the other hand with the chassis. This embodiment has the advantage that the transmission ratio is easily adjustable. In addition, the Y- or V-shaped lever may be arranged so that the brake shoe acts on the inside of the rim or a brake drum arranged on the rim. In other words: the

Brake shoe engages behind seen in the direction of the rear of the rim or the brake drum and thus enhances the braking effect.

Conveniently, the chassis is made of light metal tube, preferably aluminum tube. With light-alloy pipes, lightweight but robust trailers can be realized. According to a particularly preferred embodiment, the drawbar and the chassis are hinged together by means of U-shaped clamps, articulated rockers or other joint parts. Advantages of such an embodiment are low friction, high robustness, low cost manufacturing and ease of assembly.

It is advantageous to provide spring means acting between the drawbar and the chassis or between the drawbar and the joint rocker or between the rocker joint and the chassis, which bias the drawbar and the chassis into an initial position in which the brake shoes are spaced from the wheels. Because of the spring preload braking occurs only when the between the drawbar and the chassis acting force is greater than the spring force. Advantageously, the spring preload is adjustable. This adjustability can be done for example with an adjusting screw which limits the travel.

When connecting the chassis and the drawbar by means of individual joint parts is strictly speaking no parallel movement of the same but a tilting movement. Accordingly, in the context of the present invention, "longitudinally displaceable" means both a parallel displacement and a tilting movement of the drawbar and chassis. [Entsprechend Entsprechend] The drawbar and the chassis can in principle be connected to one another in a "longitudinally displaceable" manner by means of other guide means Embodiments known for such parallel guides.

The brake shoes can attack to achieve a braking effect directly on the tire. However, it is advantageous that the brake shoes engage to achieve a braking effect on the rim or a brake drum formed on the rim. An advantageous embodiment provides that the rim and the brake drum are made in one piece as an injection molded part.

Conveniently, the drawbar is h-shaped. This has the advantage that it can be attached laterally to a bicycle frame. Preferably, the drawbar extends below the chassis. This has the advantage that the movable chassis for the attachment of body parts such as seats is freely accessible. According to another embodiment, the drawbar extends above the chassis. However, it is conceivable that the drawbar is arranged at the same height as the chassis (drawbar is next to or between the chassis frame).

Advantageously drawbar and chassis are spaced apart in the vertical direction. The distance between drawbar and chassis can be used to optimally convert the accumulation force into braking force (lever effect). Conveniently, the distance between the drawbar and chassis is at least 3 cm, but preferably at least 4 cm.

The invention will be described in more detail below with reference to the figures based on application examples. The same reference numerals are used in the figures for the same parts. It shows: Fig. 1 The basic structure of a known trailer with overrun brake consisting essentially of a drawbar and a chassis, which via

Joints connected to the drawbar and is longitudinally displaceable; Figure 2 is a perspective view of another embodiment of a trailer with a novel, formed on the rim brake drum with wedge-shaped cross section.

Fig. 3 is a partial view of the trailer of Figure 2 on an enlarged scale.

Fig. 4 is a perspective and schematic view of an inventive

Embodiment of a self-braking trailer with a Y- or V-shaped brake shoe carrier; Fig. 5, the braking device of the embodiment of Fig. 4 in an enlarged

Scale; Fig. 6 is a schematic illustration of the forces acting during the braking process

(Self-servo effect); Fig. 7 Schematically and in partial view of a second embodiment of an inventive trailer with the brake in the idle state; Fig. 8 The embodiment of Figure 7 during braking.

Fig. 9 is a plan view of a fourth embodiment of a brake;

Fig. 10 is a sketch with a brake device with two brake shoes, located on the

Can wedge brake drum;

FIG. 1 shows a trailer 11 with a chassis 15 and a drawbar 13 arranged on the chassis 15. The chassis 15 and the drawbar 13 are connected to one another in an articulated manner by means of the articulated pieces 17a, 17b, so that a relative displacement of drawbar 13 and chassis 15 in the longitudinal direction, which at the same time corresponds to the direction of travel (arrow 19) is possible.

On the chassis 15, a wheel 21 is freely rotatably mounted on opposite sides. In addition, the chassis 15 carries a structure not shown in the figures, in which, for example, 1 or 2 children can find space or is suitable for load transport.

The drawbar 13 extends to the wheels 21. At the end of the arms and at a distance in front of the wheel 21 a respective brake shoe 23 is arranged. The distance of the brake shoe 23 to the wheel 21 is smaller than the maximum possible relative displacement distance of drawbar 13 and chassis 15th

Between the drawbar 13 and the chassis 15 preferably acts a spring 25, which drawbar 13 and chassis 15 in an initial position biases (Figure 1). In the initial position drawbar 13 and chassis 15 are spread apart at maximum, and the brake shoe 23 is located at a distance in front of the wheel 21. In operation, when the towing vehicle is decelerated and the trailer runs or when driving down, the chassis 15 pushes against the force of Spring 25 forward and the wheel then comes into contact with the brake shoe 23. The stronger the force acting on the trailer overrun force (deceleration of the tractor, incline) the greater the frictional force between the brake pad 23 and the wheel 21st

When trailer shown at the front end of the drawbar 13 a not shown hitch 29 is provided. By means of the hitching device 29, the trailer 11 can for example be attached to a bicycle.

Figures 2 and 3 show another embodiment, in which the drawbar 13 is arranged below the chassis 15. In this case, two wheels 21 are rotatably mounted on opposite sides of the trailer 11 by means of one axle 39 on the chassis 15. The drawbar 13 is in this embodiment asymmetrically on one side of the

Trailer and extends with the two arms 27a, 27b to about the wheel hub. By means of the connecting pieces 17, the arms 27a, 27b are pivotally connected to the chassis 15, so that a relative displacement between the drawbar 13 and the chassis 15 is made possible. The maximum displacement distance is limited by stops 41, 43. In this case, the first stop 41 is connected to the chassis 15, e.g. by a welded connection, firmly connected, and the second stop 43 is connected to the drawbar 13, respectively. firmly connected to the arm 27b of the drawbar. The spring 25 now acts between the stops 41,43 and holds the chassis 15 and the drawbar 13 in the starting position, in which the brake shoes are spaced from the wheels 21. It is also conceivable to provide a lock which prevents a relative displacement of drawbar and chassis, so that the overrun brake is disabled. This could be done in the trailer according to Figures 2 and 3, characterized in that the gap 45 would be filled between the stop 43 and the chassis frame with a spacer.

The inventive embodiment of a trailer according to Figures 4 and 5 is characterized in that the brake shoe 23 from - seen in the direction of travel - the rear of the inside of the rim 36 or formed on the rim 36 brake drum 35 attacks. According to a preferred embodiment, the rim and the brake drum are an injection molded part. For this purpose, on the drawbar 13 and the chassis 15, a V- or Y-shaped lever 49 with one leg 51 on the drawbar 13 (pivot point 52) and articulated with the other leg 53 on the chassis 15 (pivot point 54). Instead of a V- or Y-shaped lever, any other design of the lever would be conceivable (eg simple angle). On the lever 49, a mounting plate 55 is arranged, on which the brake shoe 23 is mounted. The lever 49 extends between the chassis 15 and wheel 21 from the articulation points 52,54 to behind the wheel 21 so that the brake shoe 23 on the inside 57 of the rim resp. the brake drum can attack. The frictional force presses the pad even more against the brake drum in the sketched construction, because shear and friction forces act in the same direction. This embodiment has the advantage that when braking by the running direction of the wheel (arrow 59), the braking effect is enhanced (self-reinforcing effect). Namely, the frictional force between the rim and the brake shoe produces a downward-pointing force component, which the brake shoe 23 even more to the rim inner side. the brake drum pushes. It should be clear to the person skilled in the art that the described self-reinforcing effect can also be achieved if the brake shoe acts on the running surface of the tire by appropriate arrangement of the lever 49.

It can also be seen from FIGS. 4 and 5 that the articulated connecting pieces 17a, 17b are designed as H-shaped spacers. By appropriate choice of the length of the spacers and the length of the leg 53, the lever ratio and thus the power ratio for the braking effect determined.

FIG. 6 shows the force relationships on the brake lever 33 which is in engagement. "A" denotes the run-up force introduced via the drawbar arms 27. It activates the brake lever 33. "N" denotes the normal force acting on the brake shoe 23, "B" denotes the brake force acting tangentially to the brake drum. The skilled person is clear that by the design of the geometry of the brake lever 33, a force transmission N / A can be realized. By a suitable choice of the bearing point of the brake lever 33 in the chassis 15 also a self-reinforcing effect can be realized: The generated braking force "B" additionally presses the brake lever 33 against the brake drum. With such a configuration, a high efficiency of the brake can be achieved in a very compact geometry The embodiment according to Figures 7 and 8 is characterized by a modified brake. This consists of a brake shoe carrier 33 which is arranged on the chassis 15 with the hinge part 17b. It is conceivable that the hinge part 17b and brake shoe supports 33 are made in one piece. During the braking process (FIG. 8), the chassis 18 shifts in the direction of travel (arrow 19). The ratio of the length of the joint part 17b between the hinge points 52,54 to the length of the hinged on the pivot point 52 brake shoe carrier 33 defines the gear ratio. In the present case (Figures 7 and 8), the gear ratio is approximately 2: 1.

An embodiment of the braking device provides (FIG. 9) that a brake drum 35 is formed on the rim 36 of the wheel 21 and the brake shoe 23 acts radially from the outside or from the inside on the brake drum. According to a preferred embodiment, the rim and the brake drum are an injection molded part. It is conceivable that the brake drum has a V-shaped notch 37, in which engages a correspondingly formed brake shoe during braking (Fig. 9).

In order to derive from the accumulation force a large braking force, a translation mechanism is provided according to the sketch of Figure 10, which can be carried out as follows: At the joint parts 17, the chassis 15 and drawbar 13 articulated connect (joints 47), are in the way brake shoes 23rd attached that this runs approximately radially against the cylindrically shaped brake drum 35 during emergence of the trailer. By a suitable choice of the geometry (length ratio of the acting lever), so a translation can be realized, that is, with a given accumulation force, a higher Andruckkraf t to the brake drum and thus a correspondingly higher braking force can be achieved. Depending on the application, the characteristic of the brake system can be designed freely. Also conceivable would be an adjustable geometry. Another advantage of this embodiment is the easy disassembly of the wheels, for example via a through-axle construction, without having to disassemble the brake system for this purpose. Instead of the joint parts 17 and separate brake shoe carrier can be used.

To enhance the braking effect, two brake shoes can be arranged one behind the other on each trailer side. In this case, a first brake pad 23 at the front and a second brake pad at the rear interact with the brake drum (FIG. 10). The present invention relates to a trailer, in particular bicycle trailer, with a consisting of light metal tubes chassis, on each of which a wheel is disposed on opposite sides. On the chassis 15, a drawbar 13 is arranged, wherein the chassis 15 and drawbar 13 relative to each other in the longitudinal direction are displaceable. At the drawbar 13 resp. A lever 33 connected to the drawbar brake shoes 23 are arranged, which, when the trailer hangs on a towing vehicle connected to this - from - seen in the direction of travel - act on the rear wheels 21 and brake them by friction. The arrangement of the brake levers 33 is preferably carried out in such a way that the efficiency is increased by a self-boosting effect. The chassis 15 and the drawbar 13 are preferably biased by spring means in an initial position in which the brake shoes are spaced from the wheels.

Legend:

11 followers

13 drawbar

15 chassis

17a, 17b connecting pieces, joint parts

19 longitudinal resp. Driving direction of the trailer

21 wheel

23 brake shoe

25 spring

27a, 27b arms of the drawbar

29 hitch

31 lead

33 Brake shoe carrier / brake lever

35 Brake drum 6 Rim 7 V-shaped notch 9 Axis 1 Stop on chassis 3 Stop on drawbar 5 Gap between stop 43 and chassis 7 Joints 9 Lever 1 1st leg 2 Linkage point on drawbar 3 2nd leg 4 Linkage point on chassis 5 Mounting plate 7 inside of the rim 9 direction of the wheel (arrow)

Claims

claims

1. trailer (11), in particular bicycle trailer, with a drawbar (13) - a chassis (15) which is coupled to the drawbar (13) and relative to the drawbar (13) substantially in the longitudinal direction of the trailer (11) around a certain distance is displaceable, at least one on the chassis (15) arranged wheel (21) of a braking device which cooperates to generate a braking effect with the at least one wheel, and the emergence of the trailer on a towing vehicle in the direction of travel (19) generated thrust as a brake drive acts for the braking device, characterized in that the braking device comprises at least one brake shoe (23), which at a short distance to the wheels (21) on the drawbar (13) or one of

Tiller (13) and the chassis (15) connecting the rocker arm (17; 17b, 33) or lever (49) is arranged such that when the trailer hangs over the brake shoe transmitted force component acts substantially in the direction of travel (19).

2. Trailer according to claim 1, characterized in that the brake shoe (23) acts radially on the wheel (21).

3. Trailer according to claim 1 or 2, characterized in that the brake shoe (23) arranged on a brake lever defining a brake shoe carrier (33; 49) which is pivotable about a pivot point, and the pivot point of the brake lever is arranged so that the frictional force between the wheel (21) and the brake shoe (23) increases the contact pressure and thereby the braking force amplified itself.

4. Trailer according to claim 3, characterized in that the brake lever (33, 49) on the chassis (15) is articulated.

5. Trailer according to claim 3, characterized in that the brake lever (33) on the drawbar (13) and the chassis (15) is articulated.

6. Trailer according to one of claims 1 to 5, characterized in that the

Chassis (15) made of light metal tube, preferably aluminum tube.

7. Trailer according to one of claims 1 to 6, characterized in that the

Drawbar (13) by means of U-shaped brackets (17a, 17b), articulated rockers or other joint parts hingedly connected to the chassis (15).

8. Trailer according to one of claims 1 to 6, characterized in that the drawbar (13) and the chassis (15) are connected by means of guide means relative to each other longitudinally displaceable.

9. Trailer according to one of claims 1 to 8, characterized in that the wheel (21) comprises a rim (36) and a tire and attack the brake shoes (23) to achieve the braking effect on the tire.

10. Trailer according to one of claims 1 to 8, characterized in that the brake shoes (23) to achieve a braking effect on the rim (36) or formed on the rim brake drum (35) engage.

11. Trailer according to one of claims 7 to 10, characterized in that between the drawbar (13) and the chassis (15) or between the drawbar (13) and articulated rocker (17) or between the rocker arm (17) and chassis (15) acting Spring means (25) are provided, which bias the drawbar (13) and the chassis (15) in an initial position in which the braking device is spaced from the wheels.

12. Trailer according to claim 11, characterized in that the spring bias of the spring means (25) is adjustable.

13. Trailer according to one of claims 1 to 12, characterized in that a locking device is provided to determine the drawbar (13) on the chassis (15).

14. Trailer according to one of claims 1 to 13, characterized in that the Drawbar (13) extends below the chassis (15).

15. Trailer according to one of claims 1 to 14, characterized in that the drawbar (13) extends above the chassis (15).

16. Trailer according to one of claims 1 to 14, characterized in that the drawbar (13) and the chassis (15) are spaced from each other.

17. Trailer according to one of claims 10 to 16, characterized in that the rim (36) and the brake drum (35) are made in one piece as an injection molded part.

18. Trailer according to one of claims 1 to 17, characterized in that the drawbar (13) is H-shaped.

19. Trailer according to one of claims 1 to 18, characterized in that the

Arms (27) of the drawbar (13) are displaceably guided on opposite sides of the chassis (15) by means of guide means in the longitudinal direction.

20. Trailer according to one of claims 1 to 19, characterized in that the drawbar (13) at least 4 points by means of articulated rockers (17a, 17b) is pivotally connected to the chassis (15).

21. Trailer according to one of claims 1 to 20, characterized in that on the drawbar (13) a hitch (29) for coupling the trailer to a towing vehicle, in particular bicycle, is provided.