The invention relates to an auxiliary device for using a screw hoist of a semitrailer landing gear, wherein the landing gear includes a screw hoist complete with a gearbox, the gearbox including a power input shaft complete with bearings as well as a gearbox frame, which auxiliary device is adapted to be fixedly fastened relative to the landing gear. The invention also relates to a corresponding arrangement.

The road tractor of a semitrailer combination is a truck equipped with a trailer dolly. A semitrailer is connected on top of the trailer dolly. The road tractor of a semitrailer is often referred to as a road traction engine, a semitrailer truck, or a tractor. A semitrailer combination is often referred to as a semitrailer lorry.

The weight of the front part of the trailer is supported on the trailer lorry. A semitrailer is commonly used in transportation between countries. Since these have normally standard dimensions, it is normal that the company owning the road tractor does not own the towed trailer, or this may be registered by some other country. An example of a normal procedure is that an empty trailer is loaded in Finland, only the trailer is loaded onboard, and another truck picks up the loaded trailer from the harbor in Germany.

The trailer is disconnected from the road tractor as follows: The locking of the trailer dolly located on top of the road tractor frame is disengaged. The front part of the trailer is equipped with so called landing gears, which are lowered. The landing gears support the weight of the front part of the trailer. The landing gears are lowered using muscular strength. Using a crank and a gearbox, the driver lowers the landing gears by winding the crank. Several different landing gear mechanisms are known. From patent publications US 4,187,733 and US 5,538,225, two-speed lifting mechanisms are known which are operated in a normal way- using a crank. In these mechanisms, a gear ratio change is incorporated in the axial movement of the crank, which allows to perform the lifting operation either fast, using reduced force, or slowly, using great force. On the other hand, several motor-driven landing gears have been proposed, such as for example in patent publication US 4,097,840 or application publication US 2003/0209896 Al . Many motor-driven mechanisms are no more suitable for manual operation at all, or operating them is difficult. Motor-driven mechanisms cannot be applied in prior art in connection with said two-speed lifting mechanisms. A known application publication US 2007/0182148 Al proposes a lifting mechanism which can be used both with a motor and manually. This solution uses special landing gears inside of which a complicated lifting mechanism is installed. Furthermore, publication WO 00/51859 is known wherein one lifting mechanism has been proposed. Publication US 2004/0104381 Al proposes a lifting mechanism which is adapted to the landing gear using weldable or drillable fitting components.

In several prior art publications, fastening of lifting mecha- nisms to the landing gear is problematic. As the lifting mechanism is often fastened to the landing gear as a separate component, it requires a separate torque arm for transmitting force from the auxiliary device to the screw hoist of the landing gear. It is often necessary to make additional bores and welds in the landing gear for fastening, and the fastening becomes complicated. Such fastenings are extremely difficult to center relative to the power input shaft of the gearbox.

The object of the invention is to provide a novel compact auxiliary device for using a screw hoist of a semitrailer landing gear, the fastening of which auxiliary device to the landing gear is simpler than in prior art solutions and the centering of which is easier. Another object is to provide an arrangement in connection with a semitrailer landing gear which is better than prior art arrangements. The characteristic features of the auxiliary device according to this invention and the characteristic features of the arrangement according to the invention are set forth respectively in the appended claims 1 and 8. The drive shaft of the auxiliary device according to the invention is always precisely centered relative to the gearbox input shaft of the landing gear screw hoist because the auxiliary device is fastened to the gearbox frame.

This object can be achieved, according to the invention, with an auxiliary device for the screw hoist of a semitrailer land- ing gear, wherein the landing gear includes a screw hoist complete with a gearbox which includes a power input shaft complete with bearings as well as a gearbox frame. The auxiliary device is adapted to be fixedly fastened relative to the landing gear and directly to connection detents arranged in the gearbox frame, which connection detents are adapted to receive the torque generated by the auxiliary device. With this, easy installability of the auxiliary device in the landing gear as well as its precise positioning and centering relative to the power input shaft of the landing gear gearbox are achieved.

Advantageously, the arrangement includes a fastening device via which the auxiliary device is adapted to be fastened to the gearbox frame of the landing gear. The fastening device may be designed according to the connections of the landing gear, in which case the fastening device is provided with holes for fastening in the corresponding positions relative to those in the gearbox frame and auxiliary device.

According to an embodiment, the fastening device is a selected fastening device from a group of fastening devices each of which is adapted for a different type of landing gear. In this way, the same basic solution can be used to fasten the auxiliary device easily and securely to different landing gears .

The fastening device advantageously includes first mounting holes for fastening a mounting iron to the gearbox frame and second mounting holes for fastening the mounting iron to the auxiliary device. The mounting holes are located in the corresponding positions relative to the connection detents and/or mounting screws in the auxiliary device and the gearbox frame.

The fastening device advantageously includes mounting screw provisions for a part of the original mounting screws of the gearbox or its guard, with the fastening device being adapted to be fastened by its first mounting holes using at least part of the rest of the mounting screws or corresponding new mounting screws. Due to the mounting screw provisions, the auxiliary device can be fastened to the landing gear without removing all mounting screws of the gearbox. It is necessary to remove only the mounting screws that are required for connecting the fas- tening device.

Advantageously, the fastening device is adapted to be fastened to the gearbox frame of the landing gear with mounting screws included in the gearbox. With the gearbox mounting screws, the auxiliary device can be fastened to the landing gear in the original connecting positions of the landing gear, whereby the fastening is easy and quick to perform. Advantageously, the fastening device is adapted to convey the torque generated by the auxiliary device to the connection detents .

According to an embodiment, the auxiliary device includes spring-operated locking pins adapted to be located inside the power input shaft of the landing gear gearbox for locking the auxiliary device to the power input shaft. In this way, steal- ing of the auxiliary device from an easily installable connection is prevented. The arrangement according to the invention is designed for use in connection with a semitrailer landing gear and the arrangement includes a screw hoist complete with a gearbox adapted in the landing gear and an auxiliary device connected to a power input shaft included in the gearbox. The auxiliary device is an auxiliary device according to any embodiment described above.

An advantage of the auxiliary device and arrangement according to the invention, compared to prior art arrangements and auxil- iary devices, is its compact size and easy installability . The auxiliary device can be advantageously installed without drilling or welding. In addition, the auxiliary device can also be manually operated. An auxiliary device according to the invention is suitable for use connected directly to the gearbox frame of standard semitrailer landing gears without any modifications in the landing gear or other equipment . Other advantageous embodiments and advantages of the invention are described below in connection with application examples . Instead of a pneumatic drive motor and operating device, it is naturally possible to use a hydraulic or an electrical power unit. For a hydraulic actuator, the trailer can be equipped, for example, with a battery operated hydraulic power unit which is charged from the road tractor during driving. Hydraulic actuators can be manufactured to quite small a size.

The invention is described below by making reference to the enclosed drawings which illustrate an embodiment of the invention, in which

Figure 1 is a lateral view of _. an embodiment of the auxiliary device according to the invention as a whole, is an axonometric view of an embodiment of the auxiliary device and arrangement according to the invention as a whole,

is an exploded view of an embodiment of the invention,

is an axonometric front view of the gearbox frame of a landing gear of the arrangement according to the invention,

is an axonometric front view of the gearbox frame of a landing gear and a mounting iron connected thereto of the arrangement according to the invention,

is an axonometric view of the auxiliary device according to the embodiment of Figure 3 without the cover,

is a lateral cross-sectional view of the auxiliary device according to the embodiment of Figure 3 , is a lateral view illustrating the fastening of a second embodiment of the auxiliary device according to the invention, with the outer casing cut open,

is a top view of the auxiliary device of Figure 8, shows the auxiliary device of Figure 8 seen from the side of the power input shaft,

is. a cross-sectional view of a corresponding auxiliary device as in Figure 8, with the gearbox power input shaft pushed in,

is a separate view of the auxiliary device according to the second embodiment as a whole,

is an exploded view of the auxiliary device of Figure 12,

is an exploded view of the assembly of the pneumatic motor of the auxiliary device of Figure 12. The reference numbers in the igures refer to the following:

1 Cylinder 31 Support iron

2 Frame component 33 Notch

5 2' Sheet-formed rotor 35 Semitrailer frame beam frame 36 Slot

3 Counter toothing 38 Fitting (compressed air)

4 Blade groove in frame 39 Compressed air pipe

6 Blade springs 40 Intermediate flange io 7 Motor blades 41 Pin connection point

8 Grooved hollow shaft 44 Reduction gear

8 ' Axial toothing 46 Actuator

9 Frame bearings 48 Operating device

10 Rear flange of motor 49 Space

15 11 Front flange of motor 50 Drive motor supply

12 Spring flange pressure line

13 Locking pin 54 Control button

14 Power input shaft 62 Crank opening for man¬

15 Spring for locking pins ual operation

20 16 Blade spring 72 Connection detents in

17 Cylinder gearbox frame

18 Piston 74 Gearbox mounting screws

19 Thrust bearing 75 Auxiliary device

20 Piston return spring 76 Landing gear gearbox 25 21 Torsion shaft frame

22 Mounting iron 77 Landing gear gearbox

23 Rear cover 81 Drive motor cylinder

24 Casing component 82 Drive motor blades

25 Front cover 83 Drive motor shaft

30 26 Name plate 84 Drive motor front bear¬

27 Control means ing

28 Landing gear 85 Cylindrical screw

29 Landing gear paw 86 Roll pin

30 Drive motor 87 Bearing in drive motor 96 O-ring

bearing pedestal 97 Bearing flange

88 Front guard of drive 98 Worm gear

motor bearing 99 Slide pin

89 Drive motor rear end 102 Power input shaft openplate ing

90 Drive motor front end 103 Extension

plate 104 Manual control crank

91 Drive motor pedestal opening

92 Drive motor shaft guard 106 Valve assembly

93 Bearing pedestal 108 First mounting holes

94 Valve 5/3 110 Second mounting holes

95 O-ring

Figures 1 - 7 illustrate a first embodiment of the auxiliary device and arrangement according to the invention, wherein the operating device and the drive motor of the auxiliary device are separately located within the auxiliary device. Figures 8 - 14 illustrate a second embodiment wherein the operating device of the auxiliary device is inside the drive motor.

The arrangement and auxiliary device according to the invention in connection with a semitrailer landing gear is shown as a whole in Figures 1 and 2. Figure 1 additionally depicts the connection of the landing gear 28 to the semitrailer frame beam 35. The auxiliary device 75 is connected to the landing gear 28 with a fastening device 22 in such a way that the connection point of the auxiliary device 75 can be aligned with the power input shaft of the landing gear 28 gearbox. In the embodiment described in the application, the fastening device 22 is a mounting iron 22, but the fastening device can also be made of some other material. Due to the mounting iron, the connection of the auxiliary device to the landing gear is fixed whereby the auxiliary device is firmly in place. When the landing gear 28 is connected to the semitrailer frame beam 35, the landing gears 28 are sufficiently far from each other and the auxiliary device 75 is located, practically for the operator, at the edge of the semitrailer. Based on Figures 1 and 2, the compact size of the arrangement and auxiliary device according to the invention is easily detectable. With the auxiliary device, lifting or lowering of the landing gear takes only about 20 seconds, at the shortest. The auxiliary device may weigh only about 20 kg.

In the arrangement, the landing gear can be equipped with a telescopic arm (not shown) . At the bottom end of the landing gear, the version shown in figures has a paw 29 for reducing the surface pressure. Instead of the paw 29, steel rollers or another support surface can also be used.

The. operator controls the auxiliary device 75 using the control means 27 shown in the figure via mechanical control valves and compressed air. The control valves are operated by pressing control buttons 54. With the control buttons 54, the operator can control the up and down movements of the landing gear as well as change the gear. In problem conditions, the operator can connect a crank to a slot at the end of a grooved hollow shaft through a crank opening 62 located in a front plate 25, for manual operation. With the crank, the auxiliary device can be operated either completely manually or just to help the drive motor in situations in which the drive motor is not capable of moving the landing gears alone. For completely manual operation, the mounting of the reduction gear can also be removed.

As shown in Figures 1 and 2, the auxiliary device 75 is locked to the gearbox 77 frame 76 of the landing gear 28 with screws 74,. which ensures successful and reliable alignment of the auxiliary device 75. The gearbox 77, the gearbox frame 76 and the mounting screws 74 are shown in more detail in the exploded view 3. In connection with this application, the gear- box frame should be understood widely, i.e., the frame is conceived to also comprise the fixed protective covers and other similar fixed constructions fastened thereto. In Figure 3, the entire auxiliary device is shown exploded to various components. With the mounting screws 74 of the gearbox 77 frame 76, the auxiliary device 75 can be accurately positioned relative to the power input shaft 14 of the gearbox 77, which would be otherwise difficult to achieve. Generally the gearbox frame is of a standard size, which facilitates the installation of the auxiliary device. Mounting irons can be manufac- tured to suit each application or they can be formed from a mounting iron that is suitable for a standard landing gear. The mounting iron is advantageously a selected mounting iron from a group of various mounting irons each of which is adapted for a different type of landing gear.

In the embodiment of Figure 3, the operating device 48 of the auxiliary device and the drive motor 30 are separately located inside the auxiliary device. The auxiliary device operates in such a way that the drive motor 30 rotates a worm gear 98 via a reduction gear 44 and thereby the frame 2, which in turn transmits the force to a grooved hollow shaft 8. In turn, the grooved hollow shaft 8 is locked to the power input shaft 14 of the gearbox 77 by means of a spring-operated locking pin 13. The power input shaft 14 transmits the force to the gear- box 77, which in turn transmits the force to a screw hoist, which lifts the landing gears.

As the drive motor of the auxiliary device, a sheet-formed rotor receiving its driving force from compressed air can be used. The operating range of a sheet-formed rotor is within high speeds of rotation, since the operating speed of a sheet-formed rotor can be 4000 - 10000 rpm. With a direct connection, lowering of the landing gear takes place too fast due to which a reduction gear 44 is advantageously installed between the drive motor 30 and the operating device 48. Advantageously, the reduction gear 44 is a worm gear with a gear ratio ranging between 1/20 and 1/200, being advantageously about 1/60. An advantage of a worm gear is its low investment cost and high gear ratio. Other gear types can also be used as the reduction gear. In the embodiment shown in Figure 3, the cylindrical screw 85 of the reduction gear 44 rotates the worm gear 98. Figure 4 depicts a standard frame 76 for the landing gear gearbox. The frame 76 includes an opening 102 for the power input shaft and an opening 104 for the manual crank. The opening 102 of the power input shaft is surrounded by a conical extension 103. In addition, the frame 76 includes connection detents 72 for the mounting screws of the gearbox frame. The gearbox frame is usually of a standard size and design, in which case its holes are always in identical places. The mounting iron can be fastened to the landing gear directly through the ready-made mounting holes in the gearbox frame, in which case the installation is extremely simple.

Figure 5 shows a mounting iron 22 fastened on top of the gearbox frame 76, the mounting iron being fastened to the frame 76 with its screws 74. The mounting iron 22 includes first mount- ing holes 108 for fastening the mounting iron 22 to the gearbox frame 76 and second mounting holes 110 for fastening the mounting iron 22 to the auxiliary device. The first mounting holes 108 are located in the corresponding position as the connection detents 72 in the gearbox frame shown in Figure 4. In addition, the mounting iron 22 includes an opening 112 for the gearbox frame 76 extension 103 as well as a crank opening 114. In turn, the mounting holes 110 for the auxiliary device are adapted to align with the holes 40 in the intermediate flange 40 of the auxiliary device, which are shown in Figure 3.

The mounting iron 22 may include mounting screw provisions 105 for a part of the original mounting screws 74 of the gearbox or its guard, with the mounting iron 22 being adapted to be fastened by its first mounting holes 108 using at least part of the rest of the mounting screws 74 or corresponding new mounting screws 74. In this way, all mounting screws of the gearbox frame need not be removed when fastening the mounting iron, , but only those mounting screws which are used for fastening the mounting iron. Thus the gearbox remains in place for the entire fastening operation, and centering of the auxiliary device relative to the power input shaft of the gearbox is easy. When fastening the mounting iron, part of the mount- ing screws may need to be replaced with longer screws. In any case, the original connection detents in the gearbox frame are used for fastening the mounting iron.

The mounting iron can be adapted to substantially conform to the surface contours of the gearbox frame. In this connection, the term "substantially" refers to that the mounting iron conforms to the surface contours of the frame at least mainly, whereby the mounting iron firmly sets against the gearbox frame. Advantageously, the mounting iron can also be made of one continuous metal block, in which case its rigidity is good. A rigid mounting iron functions efficiently as a torque arm. The mounting iron can also be manufactured by casting or pressing, but also by welding using several pieces. Figure 6 shows an axonometric view of the auxiliary device according to the embodiment of Figure 5 without the outer cover. For controlling the arrangement according to the invention, the auxiliary device 75 can have a 5/3 valve 94, which is used to transfer operator commands to the drive motor 30 and the operating device 48. Pressure lines (not shown) for conveying the pressure depart from the valve 94 leading to the drive motor 30 and the operating device 48. At the end of the grooved hollow shaft 8, there is a slot 36 for the manual operation crank, to which slot the crank can be attached using a fitting component.

Figure 7 shows a lateral cross-sectional view of the auxiliary device 75 of the embodiment of Figure 5. A worm gear 98, fas- tened to a frame 2, is used to convey the force coming from a reduction gear 44 first to the frame 2 and further to a grooved hollow shaft 8 via slide pins 99. From the grooved hollow shaft 8, the force is transmitted to the power input shaft 14 of the landing gear gearbox by means of spring-operated locking pins 13. The spring 15 of the locking pins 13 is shown in Figure 3. The frame 2 can be made of aluminum, for example, and its construction can be lightened with various openings. The slide pins can be made of plastic, for example, for reducing the sliding friction. The design of the slide pins 99 can be, for example, round, in which case corresponding profiles are made in the grooved hollow shaft 8 and the frame 2, which together enable conveying the force from the slide pins to the grooved hollow shaft 8. Due to the slide pins 99, the grooved hollow shaft 8 can move axially during the axial movement and, at the same time, it is capable of transmitting the rotating motion coming from the drive motor to the power input shaft of the landing gear gearbox. The piston 18 of the actuator 46 can be made of plastic by- injection molding, for example. With the injection molding technique, the piston can be manufactured in two parts in which case manufacturing of the groove required by the sealing ring is non-problematic. The piston can also be lightened by leaving an empty space inside the outer covers.

Figures 8 - 14 illustrate the auxiliary device and the arrangement in combination with an auxiliary device according to another embodiment. Advantageously, the fastening of this auxiliary device to the landing gear is also performed with a mounting iron 22. According to Figure 8, the valve assembly 106 can be installed leaning to a support iron 31 at the bottom of a casing component 24, below the drive motor 30. The pressure medium connections between the valve assembly and the drive motor are not shown.

Figure 9 shows a top view of the auxiliary device. As shown in Figure 10, the grooved hollow shaft 8 is ready to receive said power input shaft 14. The auxiliary device of this embodiment is also suitable for use directly in connection with standard semitrailer landing gears without any modifications in the landing gear or the equipment. The auxiliary device can be connected to the bolts or screws of the landing gear gearbox, in which case the alignment of the power input shaft of the landing gear gearbox relative to the grooved hollow shaft 8 of the auxiliary device is accurate, and the auxiliary device functions correctly. For non-standard landing gears, the mounting iron can be formed suitable for each case.

A simplified modification can be made from the above auxiliary device according to the figures by changing the operating device to a manual one in which case the cylinder 17 according to Figure 7 and the cylindrical piston 18 would be removed or at least inoperable. Advantageously, both axial positions of the shaft include holding means, for example, a spring-suspended ball that holds the axial bearing axially in place (not shown) . A knob (not shown) can be used at the end of the torsion shaft 21 for facilitating manual operation.

Figure 11 shows a lateral cross-sectional view of the auxiliary device of a second embodiment. The auxiliary device according to the embodiment of Figure 11 differs from the first embodiment of Figure 7 in that this embodiment is implemented without a worm gear 98 and an empty space 49. Instead of these, there are blades 7 associated with the drive motor, springs 16 for the blades, and blade grooves 4 in the frame 2. Otherwise the construction is corresponding to the embodiment of Figure 7. With the arrangement of the embodiment of Figure 7, in which the drive motor and the operating device are separate, easy serviceability of the auxiliary device is achieved. For example, servicing the drive motor is notably easier when it is within the cover of the- auxiliary device as a separate part which can be easily removed for servicing.

In this second embodiment according to Figure 11, the auxiliary device comprises a casing having a back cover 23, a casing component 24 and a front cover 25. These also carry con- trol valves, which are described below. Fastened to the casing by means of an intermediate flange 40, there is a mounting iron 22 with which the auxiliary device is further connected to an existing lifting leg and, at the same time, the crank is removed from the power input shaft 14, if it has been con- nected thereto.

Additional force is supplied by a known method through the power input shaft to the lifting mechanism of the landing gear. At the same time, the power input shaft also operates the gearbox of the lifting mechanism by moving it in and out for a selected distance in the axial direction. The shaft is extended outwards while the cylinder 17 is unpressurized and the return spring 20 of the piston 18 pushes the cylindrical piston 18 inside the cylinder 17 by means of a thrust bearing 19. Here the thrust bearing 19 rotates relative to the cylindrical piston 18, which moves only axially within the perimetric cylinder 17 that is fixedly mounted to the front bearing.

The drive motor comprises as its main components a rear flange 10, a cylinder 1 and a front flange 11, with a sheet-formed rotor frame 2 ' complete with its blades 7 mounted between these. The blades 7 are installed in the grooves 4 of the sheet-formed rotor frame 2 ' . The sheet-formed rotor frame 2 ' is set rotary supported by the frame bearings 9 which are carried by the front and rear flanges 11 and 10. In a method known as such, the lamella blades are tensioned against the outer cylinder using the springs 16 of the blades 7. However, opposing lamella blades cannot be tensioned here with one spring, because the sheet-formed rotor has a hollow shaft. Therefore the springs 16 are placed in deep openings formed in the lamella blades, and thus each spring is pressed to the bottom of the groove 4.

The sheet-formed rotor frame 2' rotates the grooved hollow shaft 8, which has axial toothing 8' . The sheet-formed frame 2 has fins or counter toothing that are suitable for this toothing permitting the grooved hollow shaft 8 to move axi- ally. The power input shaft 14 is fastened to the grooved hollow shaft 8 with locking pins 13. The locking pins 13 and their spring 15 are placed inside a bore located in the power input shaft 14 of the landing gear gearbox. This bore can be found in all standard gearbox shafts. The opposing locking pins 13 are pressed to the notches 33 in the grooved hollow shaft 8 by the spring 15 located between the locking pins 13, whereby the locking pins 13 transmit a force from the grooved hollow shaft 8 to the power input shaft 14 in all conditions. As an extension to the grooved hollow shaft 8, it is possible to use a torsion shaft 21, which is fastened with a cotter by the mounting point 41. With the torsion shaft 21, the lifting leg can still be operated with a crank as before. In Figure 11, pressure is applied to the cylinder 17 of the operating device through a compressed air pipe line 39 and a fitting 38, whereby the piston 18 presses the grooved hollow shaft 8 inwards via a thrust bearing 19. The return spring 20 of the piston 18 simultaneously compresses by the force of the pneumatic cylinder.

Figure 12 shows the auxiliary device according to the second embodiment as a whole. As shown in Figure 13, the auxiliary device is composed of a few main parts: mounting iron 22, rear cover 23, casing component 24, drive motor 30, front cover 25, valve assembly for control means 27, name plate 26, and torsion shaft 21. As shown in Figure 14, the main parts of the drive motor are: rear flange 10, outer cylinder 1, drive bearings 9, grooved hollow shaft 8, sheet-formed rotor frame 2', return spring 20 for the piston 18, spring flange 12, thrust bearing 19, piston 18, cylinder 17, and front flange 11.

The drive motor of the auxiliary device should advantageously be of a type that rotates to two directions in order that the landing gear can be lifted and lowered in a controlled way. The drive motor used in the second embodiment of the invention is a sheet-formed rotor of the type that rotates fast to two directions, removing air from the center. Compressed air can be supplied to the sheet-formed rotor from two different di- rections depending on whether lifting or lowering of the landing gear is concerned. Compressed air can be removed, for example, through exhaust openings placed symmetrically relative to the supply openings . An advantage of a pneumatic sheet-formed rotor is a good torsional moment when starting the drive motor. In addition, compressed air is easily available in a semitrailer.

According to an embodiment, electric control can also be ar- ranged for the control valves, which allows the operator to perform lifting and lowering of the landing gear from the vehicle. In such an arrangement, the control valves are supplemented with a solenoid which is responsible for the valve movement .