AU2013101668A4 - Double articulated high speed stable dolly. - Google Patents

Abstract

Double Articulated High Speed Stable Dolly The invention described is a dolly designed to link trailers in a multi-trailer combination vehicle wherein the invention is to rotate the leading axle on a dolly in response to articulation of the drawbar about a pivot on the dolly frame to create the advantages of improved stability through a ratio steer response which acts to correct high-speed transient off tracking. In its simplest form, this correction is achieved by an overhang drawbar acting on a steer link to the front axle. A second form of the invention increases the steer response to articulation through a telescoping lever actuated from the front end of the drawbar by a second articulation point above or below the main drawbar where it is mounted to the towing vehicle. Stop means prevent further articulation of the drawbar past the point where such an articulation would contribute to high-speed stability. These stop means, then convey an advantage in low speed turning as the front axle is rotated in the direction of the turn, thus reducing wear on tyres such as occurs on fixed axle dollies. ig.*M-\ a A Ham"\""""" ~~~\ MN,'\ mom a oil.

Description

EDITORIAL NOTE 2013101668 There are three pages of description, the last page is not page numbered.

1 Double articulated high speed stable dolly. The present invention is generally directed to road transport vehicles and in particular to vehicles used for carrying loads at higher mass limits. Vehicle used for the transport of goods range from a simple truck with a rigid body though articulated "semi-trailers" to multi trailer combination vehicles such as "road trains". In a number of cases vehicle performance is assisted and combination vehicles are made possible by the use of a sub frame attaching to the vehicle via a turntable which allows the sub frame to rotate about a substantially vertical axis with respect to the vehicle body. In the simplest form, known as a "single axle dolly" the sub frame is at the front of a trailer body, supported by a single axle, and connects to a towing vehicle via a drawbar, thus allowing a multi axle trailer having one or more axles at the rear of the trailer. To carry heavier loads, such a sub frame may be supported by more than one axle. This leads to side stress on tyres and pavement while turning. A second problem associated with a dolly is that it can become directionally unstable at high speed, a phenomenon known as high-speed transient off tracking. This directional instability can be magnified in the trailer being towed behind the dolly a second phenomenon known as rearward amplification. These two features of the dolly are known to be a compromise of vehicle safety. It is an object of the present invention to rotate the leading axle on a dolly in response to articulation of the drawbar about a pivot on the dolly frame to create the advantages of improved stability through a ratio steer response which acts to correct high-speed transient off tracking. In its simplest form, this correction is achieved by an overhang drawbar acting on a steer link to the front axle. A second form of the invention increases the steer response to articulation through a telescoping lever actuated from the front end of the drawbar by a second articulation point above or below the main drawbar where it is mounted to the towing vehicle. Stop means prevent further articulation of the drawbar past the point where such an articulation would contribute to high-speed stability. These stop means, then convey an advantage in low speed turning as the front axle is rotated in the direction of the turn, thus reducing wear on tyres such as occurs on fixed axle dollies.

2 Summary of the invention. According to the invention there is provided a dolly for use in linking trailers front to rear. A ring(R) on the front of the drawbar (A),(A frame), of the dolly engages a pin centrally located on the towing trailer and contained within a mechanism known to those familiar with the art as a ring feeder. This device provides a means for the ring to engage accurately from a position of slight misalignment. The body of the dolly (B) engages a kingpin under the front of the following trailer by means of a quick hitch assembly, known as a fifth wheel (C). This allows the body of the dolly to pivot with respect to the trailer being towed. The drawbar (A), attaches to the dolly via a rotational member, normally a ball race turntable (D) such that the drawbar is free to rotate with respect to the body (B). The drawbar (A) is able to articulate in the vertical plane through pivot mountings (L) to accommodate differential vertical movements. There is a rearward extension (E) of the drawbar behind the centre of rotation of rotational means (D). This is pivotally attached to a steering link (F). This steering link connects to a suspension mounting plate (G) for the front axle (H). This suspension mounting plate (G) attaches to the body (B) by means of a turntable (J). Stop means (K) is provided so that the drawbar can only rotate with respect to body (D) within the limited range where action of the mechanism corrects high-speed transient off tracking. In a second iteration of the invention, the responsiveness of the steering is increased by a telescoping secondary steering arm (M) mounted above the drawbar and pivotally attached to the towing vehicle at a point rearward of ring (R) with a similar ring (S) on the main drawbar (A) . This arm is pivotally attached to body (B) at a point concentric to rotation means (D) via similar means (N) such that its rearward extension (L) connects to steer link (F) Diagram 1 shows a perspective view of the dolly. Diagram 2 shows upper and lower views Diagram 3 shows a sectional view of the possible second iteration with the telescoping secondary steer arm..

Sequence listing. Field of the invention. Invention description. Summary with drawing references. Claims. Abstract. Drawings.

Claims (5)

1. A dolly , with two or more axles, one of which is rotated in response to articulation of the drawbar.

2. A dolly with steered axle or axles having stop means which limit rotation of the drawbar with respect to the body of the dolly

3. A dolly with steered axle or axles having a locking and unlocking device which allows rotation of the drawbar with respect to the body of the dolly, said locking device engaging for the purpose of reversing.

4. A dolly with telescoping secondary steer link mounted above the drawbar and pivotally attached to the towing vehicle at a point rearward or forward of ring of the main drawbar.

5. A converter dolly having a drawbar attaching to the dolly frame by a rotating means such that it can pivot horizontally with respect to the dolly frame.