SAFETY DEVICE FOR ARTICULATED SEMI-TRAILERS

Abstract: Safety device for articulated semi-trailers such as those that are integrated into industrial vehicles to prevent the semi-trailer and the towing vehicle from folding against each other, a situation also known as "jack-knifing". The device is characterized in that it has a platform on which a rotational plate provided with the corresponding anchoring and braking means is mounted so that, as a result of the action of said means, the arm included in said plate prevents undesirable turns of the semi-trailer, which could have serious consequences.

Description: The present descriptive memory refers, as its title indicates, to a safety device for articulated semi-trailers such as those used in industrial vehicles to prevent the towing vehicle and its attached semi-trailer from folding against each other, commonly known as "jackknifing". Currently, many different types of safety or "anti-jackknifing" devices are widely known. Most of them are integrated into the rotational point called the fifth wheel, which joins the towing vehicle with the semi-trailer, as can be seen in the document US 3 850 449 A, which discloses all features of the preamble of claim 1. This device consists in a fluid cylinder and piston assembly connected to the vehicle brake system. Other of those devices, protected by the document US2773702A, consists of a valve installed in the aforementioned fifth wheel, so that when the wheel acts on the valve, it triggers the vehicle's brakes. It is also very common a mechanism, as the protected by the document US3972542A, consisting in a manually extending part that blocks the rotation introducing in the V-slot of the fifth wheel. All this kind of devices have the same disadvantage, that is, most of them are mounted onto or installed in the fifth wheel, which means that any unexpected failure of its automatic parts would leave the towing vehicle at the mercy of the trailer's momentum, which in most cases results in serious accidents. The US3807764A document uses a rotational arm, connected with the vehicle braking system, that has a link connecting the arm with a point in the trailer. Also the US2709088A document is very similar to the aforementioned US3850449A one, except in which are not mounted in the fifth wheel. To solve the problems affecting this sector, the safety device for articulated semi-trailers which is the subject of the present invention has been developed. It is situated on the chassis of the towing vehicle, whilst the end of its telescopic arm is attached to the front of the semi-trailer. On (top of) the platform there is a plate that rotates both ways and has a transversal bar fixed onto it that can swing on its supporting and rotational point. At both ends of this bar there is a heavy spring that absorbs the vibrations generated by the towing vehicle and the semi-trailer. One end of the bar can be extended and has the hitching component in which the articulated semi-trailer's axis is housed. The aforementioned extensible bar extends in accordance with the maneuvers carried out by the vehicle. The circular plate may have a slot that extends from its edge to its center. A part called a safety latch slides along this slot and is connected to at least one pneumatic cylinder, or an electrical or any other mechanism, located on top of the plate itself. As a result of the action of this cylinder, the latch slides along a guide piece towards the edge or the center of the plate, depending on the desired status of the plate, either rotating or locked when the latch runs into the stops fitted on the plate's base and under it. As additional components of the transversal bar, at least two shock absorbers have been fitted onto the sides of the axis, they are joined to the bar holder at one end, and to the plate's base at the other. The purpose of these shock absorbers is to absorb the weight of the hitch, making it easier to hitch and unhitch it. Alternatively, the plate can consist of three circular parts of variable thickness; the bottom one is fixed to the base and does not move, whereas the top one is linked to the bar holder by means of an important rotational axis that allows the bar or arm to swing, thus allowing the radial rotation of this top part when the electromagnetic break is not activated. Between the aforementioned top and bottom parts, there is an intermediate part, also circular, linked to the top one by means of its multiple pitons, which are inserted in the corresponding holes drilled in this intermediate floating part. When the electromagnetic brake is activated, the intermediate floating part is anchored on to the bottom part, the braking or anchoring power being determined by the electrical intensity sent to the plate from the unit's cab, where the corresponding control is situated. Once the intermediate part is held against the bottom one, the top one, which has the arm attached to it, also becomes immobilized by means of the aforementioned pitons that link the top and floating intermediate parts. On the edge of the top part there is a safety component that, when activated with a pneumatic control, allows a latch to come out and stop the rotation of the plate as it runs into the corresponding stops. In this optimal assembly of the device being described, the bar that has the arm also has an important threaded section in its center. This section, housed in the bar holder, will make it easier to control the bringing together of the arm's hitch to the semi-trailer axis. For easier handling of the arm, a compression spring is located on the top part of the plate, on which the bar that has the arm rests. The safety device for articulated semi-trailers being put forward has the essential advantage of the simplicity of its mechanism, which prevents the semi-trailer from going out of control and folding against the towing vehicle, a movement commonly known as "jackknifing". To better understand this invention, the optimal assembly is represented in the annexed plan. In this plan: Figure -1- shows a top view in perspective of the invention. Figure -2- shows a plan view where the bar and its associated arm have been omitted to make the drawing more clear. Figure -3- shows a front view of the device, with the safety latch towards the edge of the plate. Figure -4- shows the intermediate part where the bars are housed. Figure -5- shows the supporting part onto which the bar holder is fixed. Figure -6- shows the plaque that has the anchoring axis that will be inserted into the device's hitch. Figure -7- shows a plan view of the towing vehicle and semi-trailer, both aligned and not aligned. Figure -8- shows a view in perspective of an alternative assembly of the device. Figure -9- shows a front view of the alternative assembly of the device. The safety device for articulated semi-trailers being put forward includes, as can be seen from the figures mentioned above, a platform (1) provided with the corresponding holes (2) through which the device will be anchored onto the towing vehicle's (3) chassis crossbars. Towards the center of the platform (1) there is an axis (4) made up of a cylindrical body (5) and a rectangular flat sector (6) with a perforation (7). On the aforementioned rotating axis (4) rests a bar holder (8) with a circular sector (9) formed by two parallel pins (10) that come out of the cylindrical hollow section (11) and that are provided with the holes (12) that will house the fixing means. A bar (13) of variable length crosses the bar holder (8) and ends at a hitching component (14) located at the end of the last telescopic section of the arm or bar (13). Both ends of the bar have shock absorbers (15) made up of a compression spring. To make it easier to handle the arm that has the hitch, there are two buffers (16), placed at both sides of the axis (4) and stretching from the bar holder (8) to the circular plate (17) of variable thickness. A slot (18) runs from the edge of the plate to its center, and a latch (19) slides along it. The latch is connected to the lever (20) that is activated manually; by a pneumatic cylinder (21); electrically or by any other system. When the latch (19) rests inside of the plate (17) while it is rotating, it runs into the stops (22) located on the platform (1); whereas if the aforementioned latch (19) is situated outside the plate (17) by means of the plate's guide pieces (23), the plate can rotate fully. As an additional component of the device being presented, there is a platform (24) that is anchored towards the front end of the semi-trailer, in such a way that its axis (25) faces the hitch (14) placed on the telescopic end of the arm (13). As can be appreciated in figure -7-, the described device is placed on the towing vehicle's (3) chassis, in front of the fifth wheel (26), thus controlling the possible rotation of the semi-trailer (27) in relation to the towing vehicle. Alternatively, the plate (17) can be replaced by another type of plate (28), made up of three circular parts of variable thickness. The bottom part (29) is anchored onto the platform (1) and cannot move, whereas the top part (30) is joined to the bar holder (8) by means of a rotating point (31). Between the aforementioned top (30) and bottom (29) parts, there is an intermediate part (32), also circular, associated to the top one (30) by means of the top part's multiple pitons (33). These cylindrical pitons (33) are lodged inside the corresponding holes (34) of the said intermediate part (32), which floats between the top and the bottom ones until it is locked by the electromagnetic device (35) activated from the towing vehicle's cab (3). On the edge of the top part (30) there is a safety device (36) that, when activated manually, with the pneumatic or similar control (37), causes a latch (38) to project and limit the plate's (28) rotation, as due to it hitting the stops (39) anchored onto the platform (1). In this alternative assembly the bar holder (40) has a central threaded hole (41), whilst the bar (42) has a threaded central section. In order to make it easier to handle the hitch (43), a shock absorber (44) has been fitted that can consist of a cylindrical spring. Now that the nature of this invention and the optimal way to manufacture it have been sufficiently described, it only remains to be said that such description is not restrictive, and it is possible to introduce changes, as long as they do not change the characteristics claimed hereunder.

Claims: Safety device for articulated semi-trailers, such as those that are installed in industrial vehicles between a towing vehicle (3) and a semi-trailer (27) in order to prevent jackknifing of the semi-trailer with the towing vehicle, comprising: a platform (1) fixed to the chassis of the towing vehicle (3); a bar (13) of variable length connected to the platform (1); a hitch (14) fixed to one end of the bar (13); characterized in that the device further comprises: a part (4) rotatably mounted on the platform (1) consisting of a cylindrical body (5) and a flat rectangular section (6) with a hole (7), with a circular plate (17; 28) of variable thickness, concentric to the cylindrical body (5); a bar holder (8) having a hollow cylindrical section (11) and two parallel wings forming a half-circular sector, the wings comprising holes to house fixing means which interact with the hole (7) of part (4) in order to connect the bar holder to the part (4), the bar (13) being fixed into section (11) of the bar holder (8); a connecting piece (24,25) fixed under the front of the semi-trailer (27), whereby in operation the hitch (14) is attached to the connecting piece (24,25). Safety device for articulated semi-trailers as described in the previous claim, characterized in that the device further comprises two shock absorbing springs (15), mounted between each end of the bar (13) and the bar holder (8). Safety device for articulated semi-trailers as described in the previous claims, characterized in that the device further comprises two shock absorbers (16) fitted at both sides of the part (4), connecting the bar holder (8) to the circular plate (17). Safety device for articulated semi-trailers as described in the previous claims, comprising a latch (19) that is able to slide in and out the plate (17) along a slot (18) from the edge to the centre of the plate (17), the latch being attached to the lever (20) that can be activated manually or by means of a pneumatic cylinder (21). Safety device for articulated semi-trailers as described in the previous claims, characterized in that when the latch (19) rests inside of the plate (17) whilst it is rotating, the latch runs into stops (22) anchored onto the platform (1), blocking the rotating movement of the plate (17) and also ,by the agency of the bar (13) and the connecting piece (24,25), limiting the movement of the frontal part of the semi-trailer, whereas when the said latch (19) is placed outside the plate (17,) through the plate's guide pieces (23), the plate can rotate freely. Safety device for articulated semi-trailers as described in the previous claims, characterized in that , the plate (28) is made up of three circular parts of variable thickness (29,30,32), characterized in that the bottom part (29) is fixed to the platform (1), the top part (30) is joined to the bar holder (8) by means of the rotational point (31), and the intermediate part (32) is attached to the top one (30) by means of multiple circular pitons (33), which are lodged inside the intermediate part's holes (34). Safety device for articulated semi-trailers as described in the previous claims, characterized in that the intermediate part (32) are usually floating between the top and the bottom ones, and then the top part of the plate can rotate freely, and therefore the frontal part of the semi-trailer (27) also can do it, whereas the intermediate part (32) can be held at will against the bottom part with the help of an electromagnetic device (35) controlled from the towing vehicle's (3) cab, limiting the movement of the frontal part of the semi-trailer (27). Safety device for articulated semi-trailers as described in the previous claims, characterized by a complementary safety component (36) fitted on the edge of the top part (30), which can be activated manually pneumatically or electrically, allowing the latch (38) to project outwards and limit the rotation of the plate (28), as it runs into the stops (39) anchored onto the platform (1), also limiting the movement of the frontal part of the semi-trailer (27). Safety device for articulated semi-trailers as described in the previous claims, characterized in that the bar holder (40) has a central threaded hole (41), whilst the bar (42) has a central threaded section, in order to provide an easy length change. Safety device for articulated semi-trailers as described in the previous claims, characterized by a shock absorber (44), usually a cylindrical spring, that makes it easier and safer to handle the hitch (43).

Inventors: MARCOS LOPEZ ANTONIO, MARCOS LOPEZ, ANTONIO
Applicants: ANTON MONTO S L, ANTON MONTO, S.L.
Application year: 2001
Main classification: B62D53
IPC codes: B62D53