GB2098152A

GB2098152A - Air deflectors for vehicles

Info

Publication number: GB2098152A
Application number: GB8114629A
Authority: GB
Original assignee: MICOM DESIGNS Ltd
Current assignee: MICOM DESIGNS Ltd
Priority date: 1981-05-13
Filing date: 1981-05-13
Publication date: 1982-11-17

Abstract

An air deflector system for articulated vehicles comprising a powered tractor and trailer combination wherein the roof of the cab of the tractor is lower than the tops of different trailers which may be towed by one of the same tractor. The air deflector system comprises an air deflector (2) which can be mounted with respect to the cab roof (4) of a powered tractor (1), means, such as jacks (9), for positioning the deflector at different angles with respect to the cab roof (4) and control means for operation by a driver within the cab for controlling the positioning means (9). The air deflector and positioning means are preferably mounted on a frame (3) secured to the cab roof (4) by clamps (7) fixed to the gutters of the cab roof. <IMAGE>

Description

SPECIFICATION Air deflectors for vehicles The present invention relates to air deflectors for vehicles and more particularly to air deflectors for articulated vehicles comprising a powered tractor and trailer combination wherein the roof of the cab of the tractor is lower than the top of the trailer.

Such air deflectors are known and their purpose is to reduce the wind resistance affecting the forward movement of the vehicle so that less vehicle drag and greater operating efficiency can be achieved.

Prior proposals for such air deflectors have included plate-like air deflectors which are attached to the roof of the cab and inclined rearwardly at a desired angle to the roof. These air deflectors are usually set at the desired angle manually from outside the cab. Since the tops of different trailers which may be towed by the same tractor are often at different heights above the top of the tractor cab roof, it is desirable to be able to adjust the angle of the deflector with respect to the cab roof such that the rear, upper end of the air deflector may be set the optimum level with respect to the top of any one particular trailer, or with respect to the top of a high load on a platform trailer. Hitherto, any adjustment to the angle of the deflector has of necessity been carried out manually from outside of the tractor cab.

An object of the invention is to provide an air deflector system having improved means for adjusting the angle of the deflector with respect to the cab roof.

According to the invention, an air deflector system for the cab of a tractor for pulling a trailer comprises an air deflector which can be mounted with respect to the roof of the cab, means for positioning the deflector at different angles with respect to the roof of the cab and control means for operation by a driver within the cab for controlling the positioning means.

The air deflector may be pivotally mounted on a support means which is secured to the roof of the cab and which also carries the positioning means.

Conveniently, the support means is secured to the cab by being clamped to the guttering of the cab roof.

The positioning means may for example, be mechanical, hydraulic or pneumatic and may be controlled in any desired manner, e.g. manually or electrically. For example, the positioning means may comprise.one or more screw jacks having one end pivotally mounted with respect to the cab roof and the other end pivotally connected to the air deflector.

The jack or jacks may be operated by a pinion associated with a worm which may be in the form of a flexible externally threaded cable. Conveniently, the worm is driven via a battery operated motor and associated gearbox. The motor and gearbox may also be carried by the support means secured to the cab roof.

In one embodiment, two screw jacks are provided for positioning the air deflector and each jack is actuated via a respective flexible worm driven by a common motor and associated gearbox.

Preferably, the control means for controlling the operation of the positioning means is calibrated so that the air deflector can be moved to a preselected position determined by a set calibrated position of the control means. For example, where the positioning means is driven by a worm which in turn is driven by a electric motor, the electrical circuit including the motor may also include a series of switches, each switch being associated with a manually actuatable control device corresponding to a preselected position for the air deflector such that when a chosen manually actuable control device is actuated, electric current through the motor is switched off when the switch associated with the chosen manually actuatable control device is operated by the worm, thereby setting the air deflector at the desired angular position and height.

In order that the invention may be more readily understood, reference will now be made, by way of example, to the accompanying drawings, in which Figure 1 is a front perspective view of part of a tractor-trailer combination in which one embodiment of air deflector system according to the invention is associated with the cab of the tractor, Figure2 shows the positioning means and associated driving means mounted on mounting bars, with the air deflector and cab omitted, Figure 3 shows a cross-sectional view through one of the multi-screw jacks of Figure 2, Figure 4 is a circuit diagram of the control means which control the movement of the air deflector, and Figure 5 is a side view of a tractor trailer combination and illustrates two different positions to which the air deflector can be moved so as to be suitably angled for trailers extending to different heights above the roof of the cab of the tractor.

Referring to Figure 1 of the drawings, there is shown an articulated vehicle comprising a powered tractor unit 1 and a trailer 35. An air deflector system associated with the tractor 1 comprises a generally planar air deflector 2 whose front edge is pivotably mounted on the front wall 3a of a box-like enclosure 3 which is secured to the roof 4 of the cab 5 of the tractor. The box-like enclosure 3 is secured to the roof of the cab by means of a pair of spaced mounting bars 6a, 6b (see Figure 2) which are fixed by clamps 7 to the guttering of the cab roof.

As can be seen from Figire-2, the box-like enclosure 3 houses two positioning means for the air deflector, which are constituted by a pair of telescopic screw jacks 8,9 the lower ends of the jacks 8,9 being pivotably mounted on respective mounting bars 6a, 6b, whilst the upper ends of the jacks are pivotally attached to the underside of the air deflector. The latter is now shown in Figure 2 for the sake of clarity.

As shown in Figure 3, the screw jack 8 comprises a lower tubular member 10 which can be rotated in its base part 11 by means of a pinion 12, this lower tubular member 10 having an insert 13 with an internal screw thread which cooperates with an external screw thread 14 on an interfitting second tubular member 15. The second tubular member 15, in turn has an insert 16 with an internalscrew thread which cooperates with an external screw thread 17 on a third tubular member 18 which interfits in the second tubular member 15, the upper end of the third tubular member 18 being pivotally connected with the air deflector 2 at 19. Jacking unit 9 is constructed in the same manner as jacking unit 8.

The pinion 12 attached to the lower tubular member 10 of each jacking unit 8,9 is driven by a respective flexible worm 21,22 for example in the form of a Teleflex cable. The two flexible worms 21,22 are driven by a common battery driven motor 23 and associated gearbox 24 which are supported by cross bars 6c and 6dwhich extend between the mounting bars 6a and 6b. Each flexible worm 21,22 is located in a surrounding guide tube 25,26 through which the worm moves. The guide tubes 25,26 each include three sections; one section 25a,26a extends between the gearbox 24 and a respective one of the housings 27 which house and pivotally mount the base parts 11 of the jacking units, whilst guide tube sections 25b 26b and 25c,26c extend respectively from the other sides of the gearbox 24 and the housings 27.The two flexible worms 21,22 are driven in mutually opposite directions bathe common gearbox 24.

The electrical circuit for controlling the motor 23 and hence movement of the deflector 2 is shown in Figure 4. This circuit includes a battery 28 which may be a 12 or 24 volt battery, for example, the normal vehicle battery fitted in the tractor 1; a main on/off switch 29, a reversing switch 30 to enable the motor and thus the worms 21,22 to be driven in opposite directions so that the jacks can raise or lower the air deflector and an ignition drop out solenoid 31 which, when the engine is turned on, keeps switch 32 open and thus prevents the air deflector system being operated when the engine is running. The circuit also includes a series of normally closed manuallyoperated switches 33a, b, c and dwhich represent different heights and angles to which the air deflector 2 may be set.With each of these switches is associated a respective one of a series of normally closed microswitches 34a, b, c and d. The actuating member of each microswitch extends through a slot 26d in guide tube 26 and these actuating members are operated by worm 22, as will be described below. The switches 33a, b, c and ci, together with switches 29 and 30 are all conveniently mounted on a control panel (not shown) located in the cab of the tractor which enables the air deflector to be readily operated by the driver of the tractor-trailer combination from his driving position within the cab.

For the purpose of illustrating the operation of the air deflector 2 it will be assumed that the tractor 1 has been travelling with the air deflector in the lowered horizontal position, thereby effectively closing the top of the box-like enclosure, with the telescopic jacking units in retracted positions, and without a trailer being connected to the tractor.

When a trailer 35 is connected up to the tractor 1, the appropriate one of the switches 33a, b, cord, representing the angle and height at which it is desired to position the air deflector, has to be selected. Initially all the switches 33a, bc, and dand the microswitches 34a, b, c, and dare closed. If, with the tractor engine turned off, switch 33c, for example, is selected and opened and the main switch 29 is then closed, current will flow through the motor 23, via microswitch 34c and switches 33a and 33b to cause the worms 21,22 to be driven via the gearbox 24. The worms 21,22 cooperate with and drive the pinions 12 to cause the tubular members of the jacks to turn and thereby cause the air deflector to pivot upwardly about the front wall 3a of the enclosure 3.

One end of the worm 22 is provided with an enlarged portion 22a which, as the worm moves in the direction of arrow x, engages successively with the actuating members of the microswitches to cause these switches to open. Since the mircoswitches 34 are effectively in parallel with the selector switches 33, the opening of microswitches 34a and 34b has no control effect as switches 33a and 33b are closed.

Thus during this movement of the worms 21 and 22, the air deflector continues to rise. However, when the end portion 22a of the worm 22 opens microswitches 34c, since selector switch 33c is also open, the current to the motor is cut off and the air deflector will stop at that angle and height, as represented by the selector switch 33c. Thus, the air deflector 2 is stopped in the desired position.

As is illustrated in Figure 5, if a trailer 36 is substituted for the trailer 35, the position of the air deflector may, by the selection of a different switch 33a,33b or 33d, be moved to the position shown in dotted lines in Figure 5 which is suitable for the height of the new trailer above the cab roof 4 i.e. with the rear end of the air deflector again approximately in line with the top of the trailer. If the air deflector has remained in the initial position shown in full lines, then part of the trailer would extend above the air deflector and this would increase the wind resistance and consequent drag on the vehicle.

The air deflector system described above enables the air deflector 2 to be readily adjusted from within the cab by the driver and also requires only a minor modification of the cab roof 4 since only a single small hole (not shown) need be provided in the cab roof for the passage of a single electrical cable which is connected to the electric motor. Such a hole may readily be plugged if the air deflector system is removed from the tractor. The control panel may conveniently be mounted on the dashboard in the tractor cab.

The air deflector 2 and the box-like enclosure 3 may be moulded from reinforced fibreglass.

In order to render the air deflector system weather resistant the jacks may be protected by a flexible casing made of plastics or rubber material, for protecting the screw threads of the tubular members. Further, the guide tubes 25,26 may be covered with plastics material and the motor 23 and gearbox 24 may be sealed and 'weather-proofed'.

Whilst a particular embodiment of the invention has been described above, various modifications may be made without departing from the scope of the invention. For example, instead of providing an electrical control system, a calibrated winding mechanism operated by hand from within the tractor cab may be employed for operating the jacks for raising and lowering the air deflector.

It will be understood that when the tractor is running without a trailer or with a low load, the air deflector is lowered horizontal on the cab roof.

The design of the air deflector shield per se can be made such as to have advantageous effects on stabilising the rear of the trailer when travelling at speed.

CLAIMS (Filed on 13 May 1982) 1. An air deflector system for the cab of a tractor for pulling a trailer, said system comprising the combination of an air deflector which can be mounted with respect to the roof of the cab, means for positioning the deflector at different angles with respect to the roof of the cab and control means for operation by a driver within the cab for controlling the positioning means.

2. A system as claimed in claim 1, in which the air deflector is pivotally mounted on a support means which is secured to the roof of the cab.

3. A system as claimed in claim 2, in which the support means also carries the positioning means.

4. A system as claimed in claim 2 or 3, in which the support means is secured to the cab by being clamped to the guttering of the cab roof.

5. A system as claimed in any preceding claim, in which the positioning means is mechanical, hydraulical or pneumatic.

6. A system as claimed in claim 5, in which the positioning means is controlled manually or electrically.

7. A system as claimed in claim 5 or 6, in which the positioning means comprises one or more jacks having one end pivotally mounted with respect to the cab roof and the other end pivotally mounted with respect to the air deflector.

8. A system as claimed in claim 7, in which the jack orjacks are screw jacks driven in rotation by an electric motor or a hand operated winding mechanism.

9. A system as claimed in claim 8, in which two screw jacks are provided for positioning the air deflector and each jack is actuated via a respective worm gear driven by a common electric motor.

10. A system as claimed in claim 9, in which the worm gear is a flexible worm, such as an externally threaded cable.

11. A system as claimed in any preceding claim, in which the control means for controlling the operation of the positioning means is calibrated so that the air deflector can be moved to a preselected position determined by a chosen calibrated position of the control means.

12. A system as claimed in claim 11, in which the control means is an electrical control means and includes a control circuit for an electric motorwhich actuates the positioning means, said control circuit including a series of switches, each switch being associated with a manually operable device corresponding to a preselected position for the air deflector such that when a chosen manually operable device is actuated, electric current through the motor is switched off when the switch associated with the selected manually operable device is operated, thereby setting the air deflector at the desired angular position and height.

13. A system as claimed in any preceding claim, in which the air deflector is so designed as to have advantageous effects on stabilising the rear of a trailer when travelling at speed.

14. A system as claimed in any preceding claim, in which the air deflector is made of reinforced fibreglass.

15. An air deflector system for vehicles su bstantially as hereinbefore described with reference to the accompanying drawings.

16. A vehicle fitted with an air deflector system as claimed in any of the preceding claims.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. running without a trailer or with a low load, the air deflector is lowered horizontal on the cab roof. The design of the air deflector shield per se can be made such as to have advantageous effects on stabilising the rear of the trailer when travelling at speed. CLAIMS (Filed on 13 May 1982)

1. An air deflector system for the cab of a tractor for pulling a trailer, said system comprising the combination of an air deflector which can be mounted with respect to the roof of the cab, means for positioning the deflector at different angles with respect to the roof of the cab and control means for operation by a driver within the cab for controlling the positioning means.