FIELD OF INVENTION

The present invention relates to rear engine low floor vehicles with a wide service door ahead of the front axle. More specifically the invention relates to an arrangement which facilitates in positioning the driver and the driver workspace on the low floor area.

PRIOR ART AND PROBLEM TO BE SOLVED

One of the prime safety aspects that a present day vehicle has to cater to is better driver visibility. Blind distance is one key parameter that is concerned with driver visibility.This aspect becomes crucial in the case of buses, especially city buses. Being operated in heavy traffic congestions and maneuvered in cramped roads, city buses require maximum driver visibility in order to reduce accidents and enhance the safety of driver, passengers and pedestrians.

Figure 1 shows an example of the present day city buses which are predominantly of the low floor type i.e. which provide a step less entry to the passengers. A typical arrangement in a low floor bus , has the driver seated over a platform (1) which is significantly elevated from the low floor level (2). This increases the blind distance, thus creating a blind spot of considerable length 'X' in front of the vehicle as illustrated in FIG 1. In order to reduce the blind distance the driver should be seated as low as possible. This is hindered due to the presence of the components of the steering system beneath the driver seat. And hence on a low floor bus the driver remains seated on a platform of considerable elevation. This not only causes greater blind distance but is also inconvenient to the driver, as the driver has to put additional effort to climb the elevation and reach the seat. Therefore, in view of the above there is a need to develop an improved arrangement of the components of the steering system which would enable the driver to be seated on the low floor level.

OBJECT OF INVENTION

The principle object of the invention is to have the driver seat and consequently the driver positioned on the low floor area of the vehicle having a wider door ahead of the front axle, thereby ensuring lesser blind distance and lesser effort for the driver whilst entering and exiting the driver workspace. Another object of the invention is to develop a steering system which can be installed in the low floor architecture without compromising its functionality. Yet another object of the invention is to develop a floor arrangement which enables to position the driver , driver seat and the steering system in the intended position and yet retain the low floor architecture.

SUMMARY OF INVENTION

The present invention, which achieves the objectives as mentioned above relates to a steering system which is capable of being installed such that all the steering linkages lay below the low floor level. The present invention also relates to the floor arrangement which is of low floor in nature i.e. providing a step less entry to passengers. The floor is such that the driver seat and the driver are positioned at the low floor level. Hence not just the passengers but the driver too has a step less entry. The steering system and the floor arrangement are designed such that they jointly aid in accommodating the driver workspace and the driver seat to be positioned on the low floor thereby providing a step-less entry to the driver and ensuring lesser blind distance while the driver is seated. In addition to lesser blind distance, this invention also provides lesser effort for driver whilst entering and exiting the driver workspace.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS

The advantages and the features of the invention are illustrated in the accompanying drawings, wherein

FIG 1 shows the side view of a low floor vehicle such as a bus with driver seated at a higher position according to the prior art;

FIG 2 shows the side view of the low floor bus with driver at low floor according to the present invention;

FIG 3 shows an isometric view of a low floor bus according to the present invention;

FIG 4 shows the side view of the proposed low floor bus with the designed steering system;

FIG 5 shows an isometric view of the steering linkages; and

FIG 6 shows a closer view of the steering linkage with the universal joints.

DETAILED DESCRIPTION OF THE INVENTION

Disclosed herein is the construction with which the subject invention is obtained. This invention is illustrated in the accompanying drawings, throughout which, like reference numerals indicate corresponding parts in the various figures. FIGS 2 and 3 illustrates an exemplary embodiment of the invention showing an arrangement according to the present invention wherein the driver is seated on the low floor (2) of a step-less entry vehicle, such as a bus, with a wide service door (24) positioned ahead of the front axle (8). The blind distance as observed in this arrangement 'Xi' is lesser when compared to the blind distance 'X' observed on a typical arrangement as shown in FIG 1. As illustrated in FIG 4, in order to have the driver floor devoid of any elevated projection, the steering gear box (3) is pushed towards the rear positioned completely behind the driver seat (4). The floor (5) over the steering gear box (3) which is slightly elevated to clear the steering mechanism is utilized as the platform for the seated passengers (6) immediately behind the driver. The drop arm (7) via the drag link (10) transmits the torque from the steering gear box (3) to the front axle assembly (8). The drop arm (7) is mounted on to the steering gear box (3) with the axis perpendicular to it as depicted in FIG 5. The drop arm (7) swings about its axis on a horizontal plane, parallel to the ground (9).

The torque from the steering wheel [11) is transferred to the bevel box (12) through the steering column (13) as in FIG 6. The bevel box (12) and the steering column (13) are interconnected by an universal joint (14). The bevel box (12) is positioned in the front portion of the bus and is installed at an angle such that it clears the angle of approach (15) as shown in FIG 4. The positioning of the steering gear box (3) well behind the driver seat (4) and positioning the bevel box (12) at an angle well in front of the vehicle ensures no hindrance on low floor space to accommodate the driver workspace, including the driver seat (4). The torque from the bevel box (12) is transferred to the steering gear box (3) through two links in series as in FIG 6. The first link (16) is connected with the bevel box (12) by an universal joint (17) and is installed at an angle in line with the bevel box such that it clears the angle of approach (15). The first link (16) is kept installed in the intended position by a bracket (18) mounted on to the bottom of the floor (2). The link (16) runs through the bracket and is supported by a bearing (19) on the inside of the bracket. Next in line installed is the second link (20) which transmits the torque from the first link (16) to the steering gear box (3). The second link is connected to the first link and to the steering gear box by two universal joints (21 and 22), one on either side of the link. The second link (20) is similar in construction to the first but is telescopic in design. The link has a slip joint (23) in the end adjacent to the steering gear box (3), thereby making it telescopic. This enables the same system to be used across vehicles of different front overhangs. The slip joint expands or collapses in accordance with the front overhang of the vehicle. The parts of the steering system which are essentially in the lower body i.e. the bevel box (12), the links (16,20) and the steering gear box (3) are positioned such that all of them lay below the low floor level (2) of the bus hence enabling the driver seat (4) and the entire driver workspace to be installed on the low floor level of the bus. Eventually the driver gets to sit on the seat with the legs positioned on the low floor level, thereby reducing the blind distance in front of the vehicle. It is to be understood that both the foregoing general description and the following detailed description of the present embodiments of the invention are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments of the invention and together with the description serve to explain the principles and operation of the invention.

WE CLAIM

1. A low floor vehicle comprising: a step-less entry low floor arrangement; a passenger door ahead of a front axle of the vehicle; a driver workspace on the low floor of the vehicle; wherein a steering system is positioned below the low floor arrangement such that the driver workspace, including a driver seat, is accommodated directly on the low floor of the vehicle thereby providing a step-less entry for a driver. The low floor vehicle according to claim 1, wherein the steering system comprises a steering gear box positioned fully behind the driver seat, the axis of the steering gear box being parallel to the plane of the ground. The low floor vehicle according to claim 2, wherein a drop arm is installed on the steering gear box having an axis perpendicular to the axis of the steering gear box and swingable in a horizontal plane parallel to the plane of the ground. The low floor vehicle according to claims 1-3, wherein torque from a steering wheel is transferred to a bevel box positioned in the front portion of the vehicle at an angle with the ground so as to clear an angle of approach The low floor vehicle according to claims 1-4, wherein two links interconnected with universal joints transmit torque from the bevel box to the steering gear box.The low floor vehicle according to claim 5, wherein the first link connected to the bevel box is supported by a bracket and bearing arrangement affixed to the bottom of the floor, the first link being installed at an angle to clear the angle of approach. The low floor vehicle according to claim 5, wherein the second link connecting the first link with the steering gear box is of telescopic type, which aids when the front overhang is customized to any length. The low floor vehicle according to the preceding claims, wherein the bevel box, first and second links and the steering gear box are positioned so as to lay below the low floor level of the vehicle. The low floor vehicle according to claim 1, wherein the passenger door is a wide door. 10. The low floor vehicle according to the preceding claims, wherein the vehicle is a bus.