GB2120620A

GB2120620A - A breakdown recovery vehicle

Info

Publication number: GB2120620A
Application number: GB08314234A
Authority: GB
Inventors: Jan-Olov Mjoberg
Original assignee: MORA HYDRAULICS AB
Current assignee: MORA HYDRAULICS AB
Priority date: 1982-05-26
Filing date: 1983-05-23
Publication date: 1983-12-07
Also published as: DE3319157A1; GB2120620B; SE8203252L; SE443750B; GB8314234D0

Abstract

A towing apparatus mounted to a breakdown recovery vehicle and comprising an elongate support member (3) for carrying a disabled vehicle, and an operating assembly (4) carrying the support member, said operating assembly (4) comprising a first power transmitting means (24) and being pivotably journalled on the breakdown recovery vehicle and arranged by means of said first power transmitting means (24) to raise or lower the support member (3) protruding freely from the operating assembly (4). According to the invention the operating assembly (4) comprises a second power transmitting means (36) and is by means of said second power transmitting means (36) arranged to move the support member (3) in its longitudinal direction with respect to the breakdown recovery vehicle. The support member (3) is telescopic and pivoted to a lifting boom (7) of the operating assembly (4). A winch (not shown) may be mounted on a connection member (10). <IMAGE>

Description

SPECIFICATION A breakdown recovery vehicle The present invention relates to breakdown recovery vehicles. Such vehicles are known which include a towing apparatus which comprises an elongate support member to carry a disabled motor vehicle, and an operating member carrying the support member and comprising a power transmitting means, the operating member being pivotablyjournalled on the breakdown recovery vehicle and being arranged by means of the power transmitting means to raise or lower the support member protruding freely from the operating member.

A problem inherent in previously known towing apparatus of the type described above is that the extent to which the support member may protrude must be limited depending on the weight of the breakdown recovery vehicle. This is a considerable drawback when recovering buses and similar vehicles which must usually be lifted at one of their axles.

An object of the present invention is to alleviate the above problem so that the breakdown recovery vehicle can safely be used also for towing buses and similar vehicles, as well as lorries.

According to one aspect of the prsent invention in a breakdown recovery vehicle on which is mounted a towing apparatus, the towing apparatus includes an operating member by which a disabled vehicle is mounted, and a pair of power transmitting means, one of which is arranged generally to cause lifting movement of the operating member and the second of which is arranged generally to cause longitudinal movement of the operating member in the direction of movement of the vehicle.

According to another aspect of the present invention the towing apparatus comprises a support member for mounting a disabled vehicle, an operating member carrying the support member, the operating member having a first power transmitting means which is pivotally connected to the breakdown recovery vehicle and which is arranged to raise the support member in order to lift the disabled vehicle and a second power transmitting means which is arranged to move the support member in generally longitudinal direction with respect to the breakdown recovery vehicle.

An important advantage gained with the towing apparatus according to the present invention is that it permits the disabled motor vehicle to be moved forwards to ensure acceptable weight distribution on the supporting axles of the breakdown recovery vehicle during transport.

The invention may be carried into practice in various ways but one specific embodiment will now be described, by way of example, with reference to the drawings, in which Figure 1 is a side elevation of the rear section of a breakdown recovery vehicle with a towing apparatus in accordance with the preferred embodiment of the invention, the towing apparatus being in the inoperative position for transport; Figure 2 is a top plan view of the vehicle and towing apparatus according to Figure 1 and shows a support member of the towing apparatus folded down and protruding in an operative position; Figure 3 is a side elevation of the vehicle and towing apparatus according to Figure 1 and shows the towing apparatus in a starting position to pick up a bus;; Figure 4 shows the towing apparatus according to Figures 1 and 3 in position to transport the bus, and Figure 5 shows the towing apparatus according to Figure 1 in position to transport a lorry.

In the drawings the rear section of a breakdown recovery vehicle is shown equipped with a towing unit or apparatus 1 proposed in accordance with the present invention and supported by an auxiliary frame 2 which is mounted to the chassis of the vehicle. The towing apparatus comprises an elongate support member 3 designed to carry a disabled vehicle, and an operating assembly 4 carrying the support member 3, to move the support member 3 both vertically and longitudinally, i.e. in the longitudinal direction of the breakdown recovery vehicle. In the embodiment shown, the support member comprises an inner, foldable boom 5 and a prong 6 journalled telescopically therein and comprising two telescopic sections. The free end of the prong 6 is designed to carry a yoke with upstanding forks (not shown) to be brought into engagement with an axle on the disabled vehicle.The prong 6 is arranged to move in and out of the fold boom 5 and be extended or shortened telescopically by means of a built-in hydraulic cylinder (not shown).

The operating assembly 4 includes an angular lifting boom 7 arranged in a vertical plane (preferably the centre plane of the breakdown recovery vehicle) and has an inner arm 8 and an outer arm 9, the latter being directed downwardly in order freely to support the foldable boom 5 of the support member 3 at its outer end. The foldable boom 5 is thus pivotallyjournalled on a horizontal axis for movement by means of a hydraulic cylinder (not shown) between an upper inoperative transport position, as shown in Figure 1, and a lower operative starting position, as shown in Figures 2 and 3. Suitable cooperating stops may be arranged, if desired, on the foldable boom 5 and the outer arm 9 of the lifting boom 7, in order to reinforce the construction in this position when the support member 3 is lowered.The lifting boom 7 and the support member parts 5, 6 are preferably made of square tubes. The arms 8, 9 of the lifting boom 7 suitably form an angle of about 900 with each other (outer sections of the arms), but other angles are feasible e.g. normaliy from 800 to 1100.

The operating assembly 4 also includes a connection member 10 arranged on the opposite side of the lifting boom 7 with respect to the foldable boom 5. As seen in plan 1, the connection member 10 as two bifurcated journalling arms 11, 12 for pivotable journalling of the operating assembly 4 about a first horizontal pivot axis 1 5 defined by two journalling bolts 1 3, 14, (see Figure 2) said bolts 13, 14 being mounted in a pair of attachment plates 1 6, 1 7 on two longitudinal beams 18, 19 of the auxiliary frame 2. The first pivot axis 1 5 is located in front of the rear wheels, i.e. between the rear wheels 20 and the front wheels of the breakdown recovery vehicle and at a predetermined distance from these rear wheels and their axles.

The connection member 10 and lifting boom 7 are pivotally joined by means of a horizontal journalling bolt 21 forming a second horizontal pivot axis 22 located at predetermined distance from said first axis 1 5 at its attachment to the auxiliary frame.

The towing apparatus is held up from the chassis 23 of the vehicle by means of a first power transmitting means in the form of two hydraulic lifting cylinders 24, 25 arranged one on each side of the lifting boom 7 and hinged by means of journalling bolts 26, 27 to respective ones of a pair of attachment plates 41, 42 on the beams 18, 19 of the auxiliary frame, the piston rods 28, 29 of the lifting cylinders 24, 25 being pivoted to journalling pins 30, 31 respectively on the intermediate part 32 of the lifting boom 7. The journalling bolts 26, 27 for the lifting cylinders 24, 25 form a third horizontal pivot axis 33 for the towing apparatus, while said journalling pins 30, 31 for the pistons 28, 29 form a fourth horizontal pivot axis 34 as is illustrated in Figure 2.The third pivot axis 33 is located at a predetermined distance from the first pivot axis 1 5 and is located substantially between the wheel pairs 20, i.e. at or in the vicinity of the supporting axle or axles. The first and third pivot axes 1 5, 33 are stationary, i.e.

they do not move in relation to each other and are located in the same or substantially the same horizontal plane and below the two other pivot axes 22, 34. With the aid of the lifting cylinders 24, 25 arranged at an angle to each other to stabilize the towing apparatus in lateral direction, the towing apparatus can be swung around its first pivot axis 15 (on the auxiliary frame), to lower or raise the foldable boom 5 and prong 6 of the support member as desired.

In the embodiment shown the connection member 10 is extended generally vertically up from the second pivot axis 22, i.e. the connection point between lifting boom 7 and connection member 10, to form an extended lever 35 of predetermined length, a second power transmitting means of the operating member, in the form of a hydraulic cylinder 36, being fitted in suitable manner between the free end of the lever 35 and the intermediate part 32 of the lifting boom. The hydraulic cylinder 36 is pivotally connected to the intermediate part 32, for instance, by means of a journalling pin 37, and the piston rod 38 is pivotally connected to the lever by a journalling pin 39.The hydraulic cylinder 36 is arranged to move the towing apparatus and thus its support member 3 in the desired direction fonvards or backwards in relation to the longitudinal direction of the vehicle, particularly when the towing apparatus is raised with the aid of the first power transmitting means 24,25 in which case a pivotal movement occurs at all four pivot axes. The connection lines between these four pivot axes form a quadrangle, the area of which changes depending on the position of the piston rod 38 of the hydraulic cylinder 26.

The lifting cylinders 24, 25 and the hydraulic cylinder 36 actuating the lever 35 can be connected individually and are double-operating.

The lifting cylinders obviously work simultaneously.

The intermediate part 32 of the lifting boom 7 is provided with two rollers 40 serving as guides for a wire (not shown) running through the lifting boom 7 to a winch (not shown) which is preferably mounted on the connection member 10. With the aid of such winch and wire, which may be provided with a hook, a vehicle which has broken down off the edge of the road can be pulled towards the breakdown recovery vehicle and then gripped and raised with the aid of the prong 6 and its forked yoke.

As mentioned above, the two lower horizontal pivot axes, i.e. the first and third pivot axes 1 5, 33 are stationary, while the upper horizontal pivot axes, i.e. the second and fourth axes 22, 34 are movable or are moved in parallel when the hydraulic cylinder 36 actuating the lever 35 is operated so that they describe arcs whose radii are determined by the length of the connection member 10 between its two pivot axes 15, 22 and by the variable length of the lifting cylinders 24, 25 including the extended parts of their piston rods 28, 29.

The invention is not limited to the embodiment of the towing apparatus described above, with a lifting boom arm hanging down freely at the rear, but can be varied and modified in many ways within the scope of the foliowing claims. For instance, the hydraulic cylinder 36 actuating the lever 35 may be replaced or supplemented by one or two hydraulic cylinders secured at suitable points between the auxiliary frame 2 and the connecting member 10. When the lifting boom 7 is raised or lowered by the lifting cylinders 24, 25 the lifting boom is swung about said second pivot axis unless it or said alternative hydraulic cylinders is/are connected to the lifting cylinders.

Claims

1. A breakdown recovery vehicle on which is mounted a towing apparatus inciuding an operating member by which a disabled vehicle is mounted, and a pair of power transmitting means, one of which is arranged generally to cause lifting movement of the operating member and the second of which is arranged generally to cause longitudinal movement of the operating member in the direction of movement of the vehicle.

2. A breakdown recovery vehicle on which is mounted a towing apparatus comprising a support member for mounting a disabled vehicle, an operating member carrying the support member, the operating member having a first power transmitting means which is pivotally connected to the breakdown recovery vehicle and which is arranged to raise the support member in order to lift the disabled vehicle and a second power transmitting means which is arranged to move the support member in a generally longitudinal direction with respect to the breakdown recovery vehicle.

3. A recovery vehicle, as claimed in claim 2, in which the operating member comprises an angular lifting boom, having an outer, downwardly directed, arm connected to the support member, an inner arm and an intermediate part interconnecting the two arms, the operating member also including a connection member which is hinged to the breakdown recovery vehicle to form a first horizontal pivot axis, the lifting boom being hinged by its inner arm to the connection member at a point remote from the first pivot axis, the first power transmission means extending between the breakdown recovery vehicle and the lifting arm to form a third horizontal pivot axis with the vehicle and a fourth pivot axis with the operating member.

4. A vehicle, as claimed in claim 3, in which the fourth pivot axis is located on the intermediate part of the lifting boom.

5. A vehicle as claimed in claim 3 or claim 4 in which the first pivot axis is located at a predetermined distance from and in front of the rear axle or axles of the breakdown recovery vehicle, and the third pivot axis is located at or in the vicinity of the rear axle or axles.

6. A vehicle is claimed in any one of claims 3 to 5 in which the first and third pivot axes are stationary and the second and fourth pivot axis are displaceable about circular arcs due to the action of the first and second power transmitting means.

7. A vehicle as claimed in any one of claims 3 to 6 in which the connection member extends beyond the second pivot axis to form a lever and the second power transmission means is pivotally connected between the lever and the lifting boom.

8. A vehicle is claimed in claim 7 in which the second power transmitting means is pivotally connected to the intermediate part of the lifting boom.

9. A vehicle, as claimed in one of claims 2 to 8 in which the arms of the lifting boom form an angle of between 80" to 1 10", and preferably 900 with respect to each other.

10. A breakdown recovery vehicle substantially as described herein with reference to the accompanying drawings.