Gear lever system Field of the invention

The present invention relates to a gear lever system according to the preamble of the independent claim. The invention relates in particular to a gear lever system adapted to conveying gearchange movements from the gear lever to the gearbox via two gearchange wires. Background to the invention

Many vehicles, e.g. trucks, with manual gear changing currently have a system with rods and links. A disadvantage of these systems is that the link system under the vehicle occupies a relatively large amount of space. DE- 19803607 refers to an example of a gearchange device whereby the gearchange movements are conveyed to the gearbox via a link system.

Using wires to effect gear changes makes it possible to achieve a solution which occupies less space than a link system under the vehicle. A gearbox in which the gears are operated by wires is provided with two gearchange wires which by being moved to predetermined positions in longitudinal directions, often by means of a gearchange servo, engage the required gear.

The object of the present invention is to propose instead of the link system a manual gearchange system with wires which not only meets the requirements of exactness of gear changes demanded by the vehicle's driver but is also advantageous in terms of production technology and is therefore economic.

Summary of the invention

The above objects are achieved with the invention defined by the independent claim.

Preferred embodiments are defined by the dependent claims. To maintain good gearchange sensation for the vehicle's driver, the gear lever needs to be not too long. The movement from neutral position to gear engaged should be of the order of 60-80 mm and the distance sideways between different gear positions be of the order of 30-40 mm.

The requirement to provide good gearchange sensation therefore makes it necessary, particularly on large vehicles, for the rotation centre of the gear lever to be situated above the fastening surface in the cab floor. Such a location would mean that the fastening of the wires to the gear lever would have to be relocated upwards from the cab floor, i.e. the wires would have to enter the cab, which needs to be avoided, inter alia for production reasons.

To be able to relocate the lever's rotation point upwards and avoid having to fit the wires within the cab, a gearchange system according to the present invention is proposed.

The gear lever system according to the present invention allows motion from the lever to be conveyed to the wires in a desired way, and results inter alia in correct pulling and pushing directions being imparted to the wires.

The advantage of this solution is that a shorter gear lever may be used despite the wires being fitted under the cab floor and not having to enter the cab.

The gear lever system also makes it possible to adapt the configuration to the pulling and pushing directions of the wires, e.g. if the gearchange servo so requires.

One solution for the gear lever mechanism is configured with a link system adapted to prevailing space requirements. The link system thus allows the movement from the lever to be conveyed to the wires in a desired way. The solution also achieves correct pulling and pushing directions for the wires. Configuring the transfer links according to the present invention thus makes it possible to keep the volume of the gearchange mechanism as small as possible. It also allows the wires to be fitted under the cab floor. Brief description of drawings

Figure 1 is a perspective depiction of a gear lever system according to the present invention.

Figure 2 is a schematic example of a gear layout.

Figure 3 is a schematic diagram of the first transfer link according to an embodiment of the present invention.

Figure 4 is a further perspective depiction of a gear lever system according to the present invention.

Figure 5 is a further perspective depiction of a gear lever system according to the present invention.

Figure 6 is a schematic horizontal cross-section of the gear lever system at the level of the spherical bearing according to the present invention.

Figure 7 is a schematic horizontal cross-section of the gear lever system at the level of the horizontal element according to the present invention. Detailed description of preferred embodiments of the invention

The present invention will now be described in detail with reference to the drawings, in which the same reference notations are used throughout for the same or similar parts.

The invention thus relates to a gear lever system (see in particular Figures 1 , 4 and 5) for wire gearchange in a vehicle, preferably a truck, whereby gearchange movements are conveyed from the gear lever 2 to two gearchange wires 4, 6 which run substantially horizontally from a location under the vehicle's driving cab and into the vehicle's gearbox. In the drawings, the gearchange wires are arranged to run through corrugated protective sleeves.

The gear lever system comprises a gear lever 2, a spherical bearing 8 with a rotation point C about which said gear lever is movable and a first transfer link 10 and a second transfer link 12 adapted to being acted upon by gearchange movements imparted via the gear lever. The first and second transfer links 10, 12 are situated close to the lower end of the gear lever. The gear lever system according to the invention allows the gear lever to be movable to right and left, as viewed by the driver, in a first gearchange movement A represented by a two-directional arrow A in the diagrams.

The gearchange movement A denotes movement in the neutral state of the gearbox and may also be indicated as perpendicular to the vehicle's longitudinal direction.

The gear lever system also allows the gear lever to be movable forwards and rearwards, as viewed by the driver, in a second gearchange movement B represented a two-directional arrow B in the diagrams.

The movement B denotes movement from the neutral state of the gearbox to desired gear positions and is parallel with the vehicle's longitudinal direction.

Figure 2 depicts an example of a gear pattern in which R represents reverse gear, C inching gear and 1, 2 and 3 are forward gears.

According to the invention, the first transfer link 10 is adapted to conveying directly to the first gearchange wire 4 a gearchange movement A which is thus substantially at right angles to the vehicle's longitudinal direction, and the second transfer link 12 is adapted, via rotation of a vertical spindle 14, to conveying to the second gearchange wire 6 a gearchange movement B which is substantially parallel with the vehicle's longitudinal direction.

The first transfer link 10 is fastened in a bearing 16 in such a way as to be movable about a horizontal lateral thrust spindle 18 which has its longitudinal axis Al at a predetermined distance from the rotation point C of the spherical bearing 8. The first transfer link is adapted to being acted upon by the gear lever via a transfer spindle 20 which has a longitudinal axis A2 running through the rotation point C of the spherical bearing. The transfer spindle has one end fastened in the lower portion of the gear lever and therefore moves when the gear lever moves, and acts via the other end upon the first transfer link via a plain bearing 22. The plain bearing allows the transfer spindle from the gear lever to be angled, to rotate and to be slid substantially at right angles relative to the first transfer link.

The first transfer link 10 further comprises a lower portion 24 with a fastening point 26 with a bearing 28 for the first gearchange wire 4, which fastening point is situated at a predetermined vertical distance h below the bearing 16 of the lateral thrust spindle 18.

Figure 3 is a schematic diagram of the first transfer link according to an embodiment of the present invention.

In the embodiment depicted in Figures 1 , 4 and 5 and also schematically illustrated in Figure 3, the first transfer link 10 is adapted to rotating about the lateral thrust spindle 18 via the bearing 16 through the action of the gear lever via the transfer spindle 20 via the plain bearing 22 which is situated forward, as viewed in the vehicle's longitudinal direction, of the bearing 16. This results in a movement of the gearchange wire 4 whereby when the gear lever effects the gearchange movement A to the right the wire 4 will move into the gearbox, and when the gear lever is moved to the left the wire 4 will be pulled outwards from the gearbox.

In another embodiment, the gearchange wire will undergo opposite movements if the bearing 16 about which the transfer link rotates is instead situated at the location where the plain bearing 22 is situated in the embodiment described above and the plain bearing 22 is situated at the location of the bearing 16.

The second transfer link 12 comprises a substantially horizontally oriented element 30 which has its one end 32 fastened articulatedly to the lower portion of the gear lever and its other end 34 articulatedly connected to a first end 36 of a first elongate link arm 38 which at an opposite second end 40 is firmly attached to the upper portion of said vertical spindle 14. The first link arm 38 is so oriented that its greatest extent is in a direction substantially at right angles to the gearchange movement B. The horizontal element 30 is connected to the first link arm 38 by a spherical bearing 42 which allows the horizontal element to undergo a certain rotation along its longitudinal axis A4 (see Figure 7) relative to the rotation point of the bearing. The vertical spindle 14 has its lower portion connected firmly to a second elongate link arm 44 which is itself fastened to the second horizontally disposed gearchange wire 6 and has an orientation substantially corresponding to that of the first link arm 38.

The vertical spindle 14 has a predetermined length of the same order of magnitude as the predetermined distance h pertaining to the first transfer link 10.

The gear lever system further comprises a mounting plate 5 on which the gear lever and the transfer links are fitted. The mounting plate is adapted to being fastened to the floor of the vehicle's cab, e.g. by threaded connections. The plate is provided inter alia with an elongate aperture 7 to enable the lower portion of the first transfer link to pass through it in order to cooperate with the first gearchange wire. The mounting plate further comprises a vertical hole appropriate to the vertical rod.

A gearchange operation comprises two phases, the first being the first gearchange movement A, i.e. the driver moving the gear lever to a desired position along the line A. This results in a rotary movement about the rotation point C, and about the longitudinal axis A3 depicted in Figure 6, causing the first transfer link, by the action of the transfer spindle, to rotate about the axis Al in such a way that, in the embodiment depicted in the drawings, gear lever movement to the right causes the forward portion of the transfer link to move upwards, with the result that the lower portion of the transfer link imparts motion to the first gearchange wire in an inward direction into the gearbox.

Gear lever movement to the left results in the first transfer link being caused by the action of the transfer spindle to rotate about the axis Al in such a way as to cause the forward portion of the transfer link to move downwards, with the result that the lower portion of the first transfer link imparts motion to the first gearchange wire in an outward direction from the gearbox. The second transfer link 12 will be substantially motionless when the gear lever is moved in the neutral state, i.e. in gearchange movement A. The second phase of the gearchange operation is by the driver moving the gear lever to a desired upward or downward gear position from the neutral state, i.e. gearchange movement B. This movement likewise takes place by a rotary movement about the rotation point C in which the plain bearing helps the first transfer link to remain in its position.

The second transfer link 12 is thus adapted to conveying movements which are imparted in longitudinal directions by the gear lever. The second transfer link therefore comprises a substantially horizontally oriented element 30 which has its one end articulatedly fastened to the lower portion of the gear lever, preferably via a bearing so that it is movable in a vertical plane. At its other end, the horizontally oriented element is connected

articulatedly to a first portion of a first elongate link arm 38 which has its opposite second portion firmly attached to the upper portion of a vertical spindle 14. The bearing which connects the horizontal element to the first link arm is preferably a spherical bearing 42 which allows the horizontal element to undergo a certain rotation along its longitudinal axis A4 relative to the rotation point of the bearing.

The second portion of the first link arm is therefore firmly attached to the vertical spindle, e.g. by a threaded connection.

The first link arm is so oriented that its greatest extent is in a direction substantially at right angles to the gearchange movement B.

As a result of the spherical bearing, the first link arm will be substantially motionless when the gear lever is moved in the neutral state, i.e. in gearchange movement A.

The lower portion of the vertical spindle is firmly connected to a second elongate link arm 44 which is itself fastened to the second horizontally disposed gearchange wire 6.

The second link arm has an orientation substantially corresponding to the first link arm. Movements of the gear lever in longitudinal directions (gearchange movement B) are thus conveyed via the horizontally oriented element to the first link arm which itself imparts motion to the vertical spindle so that it rotates along its vertical axis. The movement of the vertical spindle imparts motion to the second link arm, which conveys the movement to the second gearchange wire.

The vertical spindle has a length 1 of the same order of magnitude as the height h of the first transfer link.

In the embodiment depicted in the drawings, rearward movement of the gear lever, e.g. when engaging gear 3 (see Figure 2), causes the first link arm to move rearwards, with the result that the vertical spindle rotates, conveying the movement to the second link arm which imparts motion to the second gearchange wire in an outward direction from the gearbox. In a similar way, forward movement of the gear lever, e.g. when engaging gear 2 (see figure 2), causes the second link arm to impart motion to the second gearchange wire in an inward direction into the gearbox. In this embodiment the first and second link arms have the same orientation. If instead they run in opposite directions, this results in reversed directions in which motion is imparted to the gearchange wire.

Typical travel distances of the gearchange wires are +/- 25 mm. Other distances may of course be catered for by changing for example the height h of the first transfer link or by changing the length of the first or the second link arm.

The present invention is not restricted to the preferred embodiments described above. Sundry alternatives, modifications and equivalents may be used. The above embodiments are therefore not to be regarded as limiting the invention's protective scope which is defined by the attached claims.