GB2540927A

GB2540927A - Folding ramp

Info

Publication number: GB2540927A
Application number: GB1509403.0A
Authority: GB
Inventors: Simon Ervin; Quinn John
Original assignee: CHIEFTAIN TRAILERS Ltd
Current assignee: CHIEFTAIN TRAILERS Ltd
Priority date: 2015-06-01
Filing date: 2015-06-01
Publication date: 2017-02-08
Anticipated expiration: 2035-06-01
Also published as: GB201509403D0; GB2540927B

Abstract

A folding ramp comprises a first 10 and a second 20 section, the first being pivotally mounted relative to a vehicle or trailer when in use and the second being pivotally mounted relative the opposing end of the first section. A control mechanism to control the movement of the ramp comprises three arms. The first 51 and second 52 arm each have one end pivotally attached to the first and second ramp sections respectively and the third arm 53 is pivotally connected to a mounting bracket 55. The free ends of the three arms are pivotally connected together. The reaction of the third arm against the mounting bracket as the first ramp section is lowered exerts a force on the second arm which rotates the second ramp section about the first ramp section and deploys the second ramp section outwardly from the first ramp section. The lowering mechanism is a double acting hydraulic ram. The connection between the free ends of the three arms may be a clevis joint. Preferably the third arm has a screw threaded adjustment means to change the length of the third arm.

Description

FOLDING RAMP Field of the Invention

The present invention relates to folding ramps that are affixed to trailers or the cargo platform of load carrying vehicles such as, but not limited to, low loaders.

Background to the Invention

Folding or ‘flip toe’ ramps adapted to be fitted to the rear of trailers, such as a low loader trailers, are well known in the art. Such ramps are generally installed in pairs, arranged side by side to provide tracks so that vehicles such as heavy plant machinery can be driven onto a trailer.

Flip toe ramps comprise a first ramp section and a second, ground engaging, ramp section. The first ramp section is pivotally mounted at one end to the rear of the trailer, and the second ramp section (i.e. the flip toe) is pivotally mounted to the free end of the first ramp section. In this way, when the ramp is in a raised configuration with the first ramp section oriented substantially vertically, the flip toe section folds flush against the first ramp section.

As a flip toe ramp is lowered towards the ground, the flip toe section swings or is deployed outwardly from the first ramp section until the first and second ramp sections are aligned in a mutual end-to-end configuration, which corresponds generally to the terminal end of the flip toe section being in contact with the ground. Thus a flip toe ramp provides an elongate ramp surface having a modest incline for items such as heavy plant to be loaded upon a trailer, but with the ability of the ramp to fold providing a significant reduction in overall height when in a raised configuration.

Lowering and raising of the first ramp section is commonly affected by one or more hydraulic rams. To control the deployment of the flip toe section, a number of alternative methods are employed in the prior art.

In one such method, a secondary hydraulic ram is connected between the first and second ramp sections, the extension of which moves second ramp section outwardly from the first ramp section. Whilst this method provides a precise movement of the flip toe, it is expensive to implement and requires additional associated hydraulic hoses, connectors and controlling elements.

In an alternative method, a cam member that is pivotally connected to the first ramp section is rotated engages with a lever in the form of a track formation on the flip toe section to move said flip toe section outwardly from the first ramp section, the cam member being moved by a double hinged arm. This method is relatively inexpensive to implement however does not provide a smooth ramp opening movement. Furthermore, if the track formation is damage or deformed through use, the flip toe may not deploy completely or correctly.

It is therefore an object of the present invention to provide an improved flip toe ramp that mitigates the disadvantages of the prior art.

Summary of the Invention

According to a first aspect of the present invention there is provided a folding ramp assembly comprising a first ramp section and a second ramp section, the first ramp section being pivotally mountable at one end relative to a vehicle or trailer in use, the second ramp section being pivotally mounted to the opposing end of the first ramp section, wherein the folding ramp assembly further comprises a control mechanism to control the opening and closing of the second ramp section with respect to the first ramp section, wherein the control mechanism comprises a first arm, a second arm, and a third arm, wherein the first arm is pivotally connected at one end to first ramp section, wherein the second arm is pivotally connected at one end to the second ramp section, wherein the third arm is pivotally fixed at one end to a mounting bracket of the ramp assembly, wherein the free ends of the respective first, second and third arms are each pivotally connected together, and wherein the reaction of the third arm against its mounting bracket as the first ramp section is lowered in use exerts a force on the second arm which rotates the second ramp section about the first ramp section thereby deploying said second ramp section outwardly from said first ramp section.

In this way, lowering of first ramp section automatically outwardly deploys the second, or flip toe, section.

Preferably, lowering of the first ramp section is affected by one or more double acting hydraulic rams.

Optionally, pivotal connection of the respective first, second and third arms is affected by means of a clevis joint provided at one end of the third arm.

In this way the first, second and third arms are interconnected and able to pivot with respect to each other.

Preferably, mounting bracket to which the third arm is pivotally connected is affixed to a mounting plate of the ramp assembly to which the first ramp section is also pivotally mountable.

Conveniently, the mounting plate is adapted for attachment to a trailer or vehicle.

Optionally, the third arm provided with an adjustment means, such as a screw threaded section, to enable length adjustment of the third arm.

Advantageously, the relative geometry and location of the mounting bracket, the first arm and the third arm is such that third arm remains substantially parallel with first ramp section throughout the raising and lowering motion of the first ramp section.

In this way, the mounting bracket, the first arm, the first ramp section and the third arm together define a parallelogram arrangement.

Advantageously, as the first ramp section is lowered, the third arm acts to continually push a terminal end of flip toe section outwardly away from the first ramp section.

In this way, the path of the terminal end of the flip toe section becomes substantially tangential to the ground at the end of its outward deploying motion.

In this way, a smooth landing of the flip toe section onto the ground is enabled.

In a further aspect of the invention there is provided a trailer comprising one or more folding ramps in accordance with the invention.

In a further aspect of the invention there is provided a vehicle comprising one or more folding ramps in accordance with the invention.

Brief Description of the Drawings

An embodiment of the present invention will now be described, by way of example only, with reference to the following drawings, in which:

Figure 1 and Figure 2 are schematic illustrations of exemplary prior art flip toe ramps showing alternative flip toe section deployment means;

Figure 3 is a schematic perspective drawing of an exemplary trailer incorporating flip toe ramps according to the present invention;

Figure 4 is a schematic illustration showing the locus of movement of the toe section of a flip toe ramp according to the present invention during deployment between a fully raised position and a fully lowered position; and

Figures 5A to 5F are a series of drawings showing the lowering and deployment sequence a flip toe ramp according to the present invention.

Description of the Preferred Embodiments

With reference to Figures 1 and 2 there is shown of exemplary toe ramps having alternative prior art toe section deployment means.

In Figures 1 and 2, flip toe ramps 1 each comprise a first ramp section 10 and a second 20, ground engaging, ramp section. The second, ground engaging, ramp section is referred to in the art as the flip toe section. The flip toe section 20 is pivotally connected to one end of the first ramp section 10 by means of hinges 30.

Lowering and raising of the first ramp section 10 is commonly affected by one or more hydraulic rams (not shown). To control the deployment of the second ramp section, a number of alternative methods are employed.

One such prior art method is shown In Figure 1, wherein a cam member 12 that is pivotally connected to the first ramp section 10 engages with a lever in the form of a track formation 21 on the flip toe section 20. A double hinged arm 13 moves the cam member 12 against the track formation 21 to move the flip toe section 20 outwardly from the first ramp section 10 as the first ramp section is lowered.

Another prior art method is shown in In Figure 2, whereby a secondary hydraulic ram 11 is connected between the first ramp section 10 and the flip toe section 20. Extension and retraction of the secondary hydraulic ram 11 is synchronised with the operation of the hydraulic ram(s) which raise and lower the first ramp section 10. In this way, extension of the secondary hydraulic ram 11 moves the flip toe section 20 outwardly from the first ramp section 10 as the first ramp section is lowered.

Referring to Figure 3, there is shown an exemplary trailer 100 to which two flip toe ramps 1 according to the present invention are mounted, one ramp being shown in a raised position and the other ramp being shown in a lowered position.

Each flip toe ramp assembly 1 comprises a first ramp section 10 and a ground engaging flip toe section 20.

The first ramp section 10 is pivotally mounted at a proximal end to the rear of a trailer 100 via mounting brackets 14. Mounting brackets 14 are preferably fixed to a mounting plate 15 that forms part of the ramp assembly and which adapted for attachment to the trailer or vehicle 100.

Lowering and raising of the first ramp section 10 is affected by an actuating means such as one or more hydraulic rams 40. In the embodiments shown in the drawings, only one ram 40 is employed. Ram 40 is a double-acting ram. Ram 40 is pivotally fixed at its lower end via brackets 41 to mounting plate 15.

It will be appreciated that while the use of a double-acting hydraulic ram is specifically described herein, any suitable double-acting actuator may be employed. For example, pneumatic, spring, or electrically powered actuators may be used instead.

The flip toe section 20 is pivotally connected to an opposing, distal end of the first ramp section 10 by means of hinges 30.

To control the deployment of flip toe section 20 with respect to the first ramp section 10 as ramp 1 lowers, there is provided opening and closing mechanism indicated generally by the reference numeral 50. In the example shown in Figure 3, only one opening and closing mechanism 50 is required on each ramp 1. However, were the size and/or weight of the ramp dictates, an opening mechanism 50 may be employed on both sides of a ramp.

Mechanism 50 comprises a first arm 51, a second arm 52, and a third arm 53.

With reference to Figure 5A, the first arm 51 is pivotally connected at one end to first ramp section 10. The second arm 52 is pivotally connected at one end to the flip toe section 20. The free ends of the first and second arms 51, 52 are each pivotally connected to a distal end of the third arm 53. Pivotal connection of the respective first 51, second 52 and third 53 arms may be affected by means of a clevis joint and pin 54 provided at one end of the third arm 53. In this way the first 51, second 52 and third 53 arms are interconnected and able to pivot with respect to each other. Other suitable pivotal connection means may be employed.

Third arm 53 is pivotally fixed at its other end to a mounting bracket 55 which is fixed to mounting plate 15 of the ramp assembly.

Third arm 53 is preferably provided with an adjustment means, such as a screw threaded section 531 (Figure 5A), to provide a degree of length adjustment to account for wear in the mechanism 50 or variances in the ramp assembly’s geometry.

The geometry and location of mounting bracket 55 and first arm 51 is such that third arm 53 remains substantially parallel with first ramp section 10 throughout its raising and lowering motion as shown in Figures 5A to 5E. In this way, mounting bracket 55, first arm 51, first ramp section 10 and third arm 53 together define a parallelogram arrangement.

With reference to Figure 5B, as first ramp section 10 is lowered by the contraction of ram 40 in use, the reaction of the third arm 53 against its mounting bracket 55 creates an initial upward force F (Figure 5B) in the direction of the distal end of the third arm 53. This force is transmitted by clevis joint and pin 54 to the first and second arms 51, 52, respectively. The force imparted by third arm 53 causes the first arm 51 to rotate about its pivotal mounting on first ramp section 10. The upward force is thus predominantly translated to second arm 52 which in turn causes flip toe section 20 to rotate about hinges 30 and thus deploy outwardly from first ramp section 10. In this way, lowering of first ramp section 10 automatically outwardly deploys flip toe section 20.

As the first ramp section 10 is lowered further (Figures 5C-5E), the third arm 53 acts to continually push the terminal end 22 of flip toe section 20 outwardly away from the first ramp section 10.

Continued lowering of first ramp section 10 and the sequence of flip toe section 20 deployment is shown in Figures 5C to 5F. When flip toe section 20 is fully deployed and substantially in contact with the ground as shown in Figure 5F, hinge 30 is closed and the first ramp section 10 and the flip toe section 20 are substantially in end-to-end alignment to create a generally flat, continuous ramp surface. A ground engaging heel 16 provided on the underside of first ramp section 10 provides auxiliary support to the ramp 1 when in ground contact and relieves the load on hinge 30.

The arrangement of the opening and closing mechanism 50, in particular the respective lengths of arms 51, 52, 53 and their respective relative locations and pivotal mounting points, is such that for a given ramp 1, the locus of motion, or path “P”, of the terminal end 22 of the flip toe section 20 as it moves from a stowed position to a fully deployed position is substantially as shown in Figure 4.

The most crucial part of this path is in the last 20-30% of the lowering movement where the lower in use edge 23 of the flip toe section 20 comes into proximity with the ground. As can be seen in Figure 4, the path of the terminal end 22 of flip toe section 20 becomes substantially tangential to the level ground at the end of its outward motion. This is because as the first ramp section 10 is lowered, the third arm 53 acts to continually push the terminal end 22 of flip toe section 20 outwardly away from the first ramp section 10.

The effect of this motion at the end of the ramp’s deployment provides a smooth landing of the flip toe section 20 onto the ground and the subsequent secure location of said flip toe section 20 while in ground contact. In this way, crashing down of the ramp onto the ground and the associated detrimental effects on the ramp are avoided.

From a lowered deployed position, raising and closure of ramp 1 is the reverse operation of the ramp deploying sequence described above. In this way, extension of hydraulic ram 40 causes the first ramp section 10 to raise, in turn causing third arm 53 and the opening and closing mechanism 50 to smoothly draw the flip toe section back to a stowed position parallel against the first ramp section 10 as shown in Figure 5A .

It will of course be understood that the invention is not limited to the specific details described herein, which are given by way of example only and that various modifications and alterations are possible within the scope of the invention

Claims

1. A folding ramp assembly comprising a first ramp section and a second ramp section, the first ramp section being pivotally mountable at one end relative to a vehicle or trailer in use, the second ramp section being pivotally mounted to the opposing end of the first ramp section, wherein the folding ramp assembly further comprises a control mechanism to control the opening and closing of the second ramp section with respect to the first ramp section, wherein the control mechanism comprises a first arm, a second arm, and a third arm, wherein the first arm is pivotally connected at one end to the first ramp section, wherein the second arm is pivotally connected at one end to the second ramp section, wherein the third arm is pivotally fixed at one end to a mounting bracket of the ramp assembly, wherein the free ends of the respective first, second and third arms are each pivotally connected together, and wherein the reaction of the third arm against its mounting bracket as the first ramp section is lowered in use exerts a force on the second arm which rotates the second ramp section about the first ramp section thereby deploying said second ramp section outwardly from said first ramp section.

2. A folding ramp assembly as claimed in claim 1, wherein lowering of first ramp section automatically outwardly deploys the second ramp section.

3. A folding ramp assembly as claimed in claim 1 or claim 2, wherein lowering of the first ramp section is affected by one or more double acting hydraulic rams.

4. A folding ramp assembly as claimed in any preceding claim, wherein pivotal connection of the respective first, second and third arms is affected by means of a clevis joint provided at one end of the third arm.

5. A folding ramp assembly as claimed in claim 4, wherein the first, second and third arms are interconnected and able to pivot with respect to each other.

6. A folding ramp assembly as claimed in any preceding claim, wherein the mounting bracket to which the third arm is pivotally connected is affixed to a mounting plate of the ramp assembly to which the first ramp section is also pivotally mountable.

7. A folding ramp assembly as claimed in claim 6, wherein the mounting plate is adapted for attachment to a trailer or vehicle.

8. A folding ramp assembly as claimed in any preceding claim, wherein the third arm is provided with an adjustment means to enable length adjustment of said third arm.

9. A folding ramp assembly as claimed in claim 8, wherein the adjustment means comprises a screw threaded section.

10. A folding ramp assembly as claimed in any preceding claim, wherein the third arm remains substantially parallel with first ramp section throughout raising and lowering motion of the first ramp section.

11. A folding ramp assembly as claimed in claim 10, wherein the mounting bracket, the first arm, the first ramp section and the third arm together define a parallelogram arrangement.

12. A folding ramp assembly as claimed in any preceding claim, wherein the third arm acts to continually push the terminal end of flip toe section outwardly away from the first ramp section as the first ramp section is lowered.

13. A folding ramp assembly as claimed in claim 12, wherein the path of the terminal end of the flip toe section becomes substantially tangential to the ground at the end of its outward deploying motion.

14. A trailer comprising one or more folding ramps as claimed in any preceding claim.

15. A vehicle comprising one or more folding ramps as claimed in any one of claims 1 to 13.

16. A folding ramp assembly as substantially described herein with reference to the accompanying drawings Figures 3 to 5F.