GB2394701A

GB2394701A - Tilt trike

Info

Publication number: GB2394701A
Application number: GB0225093A
Authority: GB
Inventors: Stuart Mills
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-10-29
Filing date: 2002-10-29
Publication date: 2004-05-05
Anticipated expiration: 2022-10-29
Also published as: GB0225093D0; GB2394701B

Abstract

A three wheeled vehicle comprises a two wheeled rear frame carrying an engine and transmission and a front frame pivotably connected at two points to the rear frame whereby a steerable front wheel is tilted and whereto a seat is mounted. The vehicle negotiates corners by a combination of front wheel tilting and steering. The pivots are preferably aligned with each other and with the front wheel road contact point. The rearward pivot is behind and above the seat, which may be inside an enclosure. Foot pedals allow a driver to mechanically control tilting and righting of the front frame. Centring of the tilt mechanism may also be assisted by the inertia of the driver's body and by a spring and damper on left and right sides. Rear shock absorption is also provided. The trike is sufficiently stable to be capable of travelling in a straight line even when the front frame is tilted to one side.

Description

PATENT APPLICATION FOR A TILTING THREE WHEELED VEHICLE

DESCRIPTION

The invention comprises of a major step forward in biting, leaning or cambering vehicle development as follows: The vehicle's frame or chassis is divided into two parts. The rear section with two wheels which carries the engine extends forward at low level under the front frame. At the end of the low level extension is the front pivot bearing, and at high level to the rear is the rear pivot bearing. These bearings carry the front frame which comprises of the pilot's seat, controls and front single steerable wheel and forks. Provision is hence made for the front frame to pivot along the substantially longitudinal axis, providing vehicle steering via biting. The steering is achieved in a conventional manner such as a motorcycle, where the weight shift to a side of the tyre where the circumference is smaller will cause the vehicle to turn in the chosen direction. At varying speeds steering and counter steering input affects the direction of the vehicle by rotation of the front wheel about its substantially vertical axis. One important feature of this invention that sets it aside from other similar creations is the line of pivot between the two frame sections. It should be noted that US Patent 4423795, US 4484648, US 04065144, US 4624469, US 3781031, US 3601213, US 4132435, US 4592441, US 4360224, US 4088199, US 5927242, WO 8702951, and EP 1070658A1, all have a longitudinal pivot between two frame sections that is either parallel to the ground or runs up higher where the single biting wheel is mounted. In all the above mentioned cases when the pivoting section is bited, the front single wheel runs off centre of the rear wheels. In the cases where two wheels are at the front and a single wheel to the rear, the same out of line affect occurs in the above listed cases.

This invention has a longitudinal pivot line that runs from the point at which the front tyre contacts the ground up towards the rear of the vehicle above the pilot's seat. One major advantage hereby created is that the pilot's body mass helps to counter balance in a pendulum fashion the front bidng frame, thus reducing the pilot effort required to bit the front frame back to the centre upright position. Hydraulic or motorised tiling systems are used in some of the above mentioned patented machines to overcome the high level of effort required from the pilot, due to pivot lines between the two frames being adopted which diner from this invention. On this invention the load imposed by the pilot's body weight is below the pivot line and so the downward force created will always pull the seat to the lowest and therefore most upright position, assuming the lateral force is less than the vertical force, as indeed it will be once a tilt turn in the vehicle is nearing completion. With correct pilot input, the vertical and lateral force will be balanced by matching the tilt angle to the speed and corner radius. When balanced, the effort on the control pedals will be minimal. If the load on the pilot's foot pedals increases, the pilot is reminded that the forces being applied to the vehicle could be better balanced by altering speed, steering or tilt angles accordingly. Secondly, as the pivot line is arranged to cut through from the high rear pivot to the low front pivot, and then to the front tyre ground contact point, then the front wheel will always remain essentially central to the two rear wheels despite tiltng when corneming. This invention provides a motorcycle type riding experience with the potential for optional luxuries such as a heater and CD radio pack with possibilities for luggage carrying capacities not normally associated with two wheeled transport.

Due to the compact and lightweight nature of this invention the running costs will be extremely low.

The engine used on the prototype is a 400cc four stroke water cooled unit.

The vehicle that this invention relates to is capable of taking corners at much greater speeds than traditional 3 or 4 wheeled vehicles, whilst remaining stable and under full manual control. The vehicle is also capable of increased cornering speeds over that of traditional motorcycles by substantially reducing the risk of lost rear traction. If motorcycles accelerate out of a comer too fast or brake the rear wheel too hard when entering a comer, the back wheel loses traction often causing the rider to involuntarily dismount. This is not the case with this invention.

Claims

- 2 - PATENT APPLICATION FOR A TILTING THREE WHEELED VEHICLE CLAIMS

1. A three wheeled vehicle that negotiates comers by a combination of front wheel being and steering. The vehicle comprises essentially of two inter-connecting frames that are referred to as front and rear. The rear section carries the enginetransmission and sits in a stable position on the ground on two wheels. The front section pivots about two points on the rear section, and has attached to it a seat and single front wheel and forks.

2. A three wheeled vehicle as claimed in Claim 1 that is capable of tilting without effecting wheel

alignment. The line of pivot runs from the point that the front tyre contacts the ground up to the rearward pivot behind and above the pilot's seat. The front section can hence be bited in relation to the rear without the front tyre moving its position on the ground in relation to the centre line of the rear wheels. This assists overall roll control, and reduces the rider input force required to return the front section to the upright position by utlising the pilots body mass in a pendulum fashion as the rear pivot is located above the seat. The pivotal foot controls operate so that when the rider's left leg is pushed forward the vehicle bits left, and at the same time the mechanism will push the rider's right foot in the opposite direction in readiness for right leg input force to bring the vehicle upright once the corner is negotiated.

3. A three wheeled vehicle as claimed in Claim 1 or 2 that is so stable that it is possible to bit left and steer right whilst the vehicle is still proceeding in a straight line.

4. A three wheeled vehicle as claimed in Claim 1 or 2 with a fully enclosed body that will protect the pilot from the elements. The involvement of a motorcycle riding experience is created with this vehicle whilst the pilot is housed in relative comfort when compared to a motorcycle. If a body was fitted to a motorcycle that enclosed the rider's feet then the rider would be unable to balance it when stationary.

5. A three wheeled vehicle as claimed in Claim 1 or 2 with a selfcentering manually operated being frame. The tilt mechanism develops a deliberate bias that loads the system in an unbalanced manner. Left and right springs and dampers are then used to balance the system, resulting in the introduction of equal spring tensions when the tilting frame is in the central upright position. Hence

a desired effect of a self-centering tilt mechanism is achieved which prevents tilt occuring involuntarily when the vehicle is stationary. The use of the springs also help assist the pilot's feel for overall roll control. Shock absorbers mounted vertically behind the seat help to stabilise the seK-centering affect and dampen out any suspension shocks from a left or right wheel which may otherwise cause bit.